Types of machines and other devices

Types of machines and other devices

Simple machines	Inclined plane, Wheel and axle, Lever, Pulley, Wedge, Screw
Mechanical components	Gear, Rope, Spring, Wheel, Axle, Bearings, Belts, Seals, Roller chains, Link chains, Rack and pinion, Fastener, Key
Clock	Atomic clock, Chronometer, Pendulum clock, Quartz clock
Compressors and Pumps	Archimedes screw, Eductor-jet pump, Hydraulic ram, Pump, Tuyau, Vacuum pump
Heat engines	External combustion engines	Steam engine, Stirling engine
	Internal combustion engines	Reciprocating engine, Wankel engine, Jet engine, Rocket, gas turbine
Linkages	Pantograph,Peaucellier-Lipkin
Turbine	Gas turbine, Jet engine, Steam turbine, Water turbine, Wind generator, Windmill (Air turbine)
Airfoil	Sail, Wing, Rudder, Flap, Propeller
Electronic machines	Computing machines	Calculator, Computer, Analog computer
	Electronics	Transistor, Diode, Capacitor, Resistor, Inductor
Biological machines	Virus, Bacterium, Cell (biology), Plant and animal, DNA computers, Human being
Miscellaneous	Robot, Vending machine, Wind tunnel

MEMBRANES

Overview of membranes.

The cell is not an amorphous sack of components, but a complex structure filled with organelles. Examples include:

1. endoplasmic reticulum
2. mitochondria
3. nucleus

Membranes are not passive barriers.

1. They control the structures and environments of the compartments they define, and thereby the metabolism of these compartments.
2. The membrane itself is a metabolic compartment with unique functions.

Membranes are dynamic.

1. They can move.
2. Their components are continuously synthesized and degraded.
3. The primary event in cell death (e.g. myocardial infarction) may be damage to the cell membrane, leading ultimately to cell death.

Preview: In the following sections we will look at membranes from the perspectives of

1. chemical components
2. structure
3. function

The chemical components of membranes

General composition.

1. The components
   • Lipid -- cholesterol, phospholipid and sphingolipid
   • Proteins
   • Carbohydrate -- as glycoprotein
2. Differences in composition among membranes (e.g. myelin vs. inner mitochondrial membrane)
   • Illustrate the variability of membrane structure.
   • This is due to the differences in function. Example:

     Mitochondrial inner membrane has high amounts of functional electron transport system proteins.

     Plasma membrane, with fewer functions (mainly ion transport), has less protein.

   • Membranes with similar function (i.e. from the same organelle) are similar across species lines, but membranes with different function (i.e. from different organelles) may differ strikingly within a species.

Distribution of lipids in membranes

1. There can be large membrane to membrane differences in lipids (compare phosphoglycerides and cholesterol in plasma membrane vs. inner mitochondrial membrane).
2. There can be large differences within classes of lipids (compare the cardiolipin of the inner mitochondrial membrane to other membranes).
3. There are also patterns of differences among the fatty acyl groups of the lipids of various membranes

The reasons for these variations are not known.

The proteins of membranes.

1. Classification of membrane proteins is operational.
   • Definition of "operational classification": based upon how a thing responds to a specified treatment (or operation), rather than upon the intrinsic nature of the thing.
   • There are two kinds of membrane proteins

     Extrinsic (or peripheral): These may be removed from the membrane, or solubilized, by mild treatment, such as shaking with a dilute salt solution. Extrinsic proteins are often thought of as being loosely associated with the membrane surface.

     Intrinsic (or integral): These cannot be removed from the membrane without treatment that destroys the membrane structure, such as dissolving it with detergent. Intrinsic proteins are often pictured as being deeply imbedded in the membrane or transfixing it.

     The biological activity of some proteins depends on whether or not they are associated with membrane.
2. Roles of membrane proteins.
   • Catalytic: enzymes
   • Receptors for signals such as hormones. Binding of the hormone to the protein transmits the signal.
   • Transport
   • Structural. The biconcave discoidal shape of the erythrocyte is due in part to the membrane protein.

Carbohydrates of membranes are present attached to protein or lipid as glycoprotein or glycolipid.

1. Typical sugars in glycoproteins and glycolipids include glucose, galactose, mannose, fucose and the N-acetylated sugars like N-acetylglucosamine, N-acetylgalactosamine and N-acetylneuraminic acid (sialic acid).
2. Membrane sugars seem to be involved in identification and recognition.

Membrane structure

The amphipathic properties of the phosphoglycerides and sphingolipids are due to their structures.

1. The hydrophilic head bears electric charges contributed by the phosphate and by some of the bases.
   • These charges are responsible for the hydrophilicity.
   • Note that no lipid bears a positive charge. They are all negative or neutral. Thus membranes are negatively charged.
2. The long hydrocarbon chains of the acyl groups are hydrophobic, and tend to exclude water.
3. Phospholipids in an aqueous medium spontaneously aggregate into orderly arrays.
   • Micelles: orderly arrays of molecular dimensions. Note the hydrophilic heads oriented outward, and the hydrophobic acyl groups oriented inward. Micelles are important in lipid digestion; in the intestine they assist the body in assimilating lipids.
   • Lipid bilayers can also form.
   • Liposomes are structures related to micelles, but they are bilayers, with an internal compartment. Thus there are three regions associated with liposomes:

     The exterior

     The membrane itself

     The inside. Liposomes can be made with specific substances dissolved in the interior compartment. These may serve as modes of delivery of these substances.

4. The properties of phospholipids determine the kinds of movement they can undergo in a bilayer.
   • Modes of movement that maintain the hydrophilic head in contact with the aqueous surroundings and the acyl groups in the interior are permitted.

     Rotation

     Lateral diffusion

     Flexing of the acyl chains

   • Transverse movement from side to side of the bilayer (flip-flop) is relatively slow, and is not considered to occur significantly.

Membranes are currently pictured according to the fluid mosaic model.

1. A lipid bilayer composed of phospholipid and cholesterol
2. Proteins. Integral proteins are shown; peripheral proteins may be loosely attached to the surface.

The difficulty with which flip-flop movement of membrane components occurs relates to the sidedness of membranes. Membrane surfaces have asymmetry -- different characteristics on the two sides.

1. There are differences in lipid composition between the sides of a membrane. The mechanism for generating this sidedness is unknown.
2. Membranes also show sidedness with respect to protein composition
   • Different catalytic proteins (enzymes) appear on the two sides of membranes.
   • Carbohydrate is mostly on the outer surface of cell membranes. It is typically attached to the portion of membrane proteins that sticks out.
3. The erythrocyte membrane provides a good model of membrane sidedness.
   • Some proteins (ankyrin, spectrin) are associated with the inner surface of the membrane.
   • Other proteins transfix the membrane (glycophorin), or loop back and forth from side to side (band 3 protein). Note that there is carbohydrate on the exterior portion of glycophorin and band 3.

Membrane fluidity -- according to the fluid mosaic model, proteins and lipids diffuse in the membrane.

Membranes separate and maintain the chemical environments of the two sides of the membrane.

Introduction: there are ion gradients across the mammalian plasma membrane. Here is a comparison of the mean concentration of selected ions outside and inside a typical mammalian cell, giving the ion, the concentration in the extracellular fluid, the intracellular fluid and the difference betwen the two.

 Na+  140 mM   10 mM  14-fold

 K+  4 mM   140 mM  35-fold

 Ca++  2.5 mM   0.1 microM 25,000-fold

 Cl-  100 mM   4 mM  25-fold

Cell membranes maintain these gradients by

• preventing ion flux
• active transport of ions from side to side of the plasma membrane.

Some substances can cross membranes by passive (simple) diffusion.

1. Types of molecules that can cross membranes by diffusion:
   • Water and small lipophilic organic compounds can cross.
   • Large molecules (e.g. proteins) and charged compounds do not cross.
2. Direction relative to the concentration gradient: movement is DOWN the concentration gradient ONLY (higher concentration to lower concentration).
3. Rate of diffusion depends on
   • charge on the molecule -- electric charge prevents movement.
   • size -- smaller molecules move faster than larger molecules.
   • lipid solubility -- more highly lipid-soluble molecules move faster.
   • the concentration gradient -- the greater the concentration difference across the membrane, the faster the diffusion.
4. Direction relative to the membrane: molecules may cross the membrane in either direction, depending only on the direction of the gradient.

Protein channels transport specific ions.

1. Ion channels exist for Na⁺, K⁺ and Ca⁺⁺ movement. These channels are specific for a given ionic species.
2. Channels consist of protein, which forms a gate that opens and closes under the control of the membrane potential.
3. Ion movement through channels is always down the concentration gradient.

Transport of molecules across membranes by carriers (mediated transport).

1. A carrier must be able to perform four functions in order to transport a substance.
   • Recognition -- to specifically bind the substance that is to be transported.
   • Translocation -- movement from one side of the membrane to the other.
   • Release -- on the other side of the membrane
   • Recovery -- return of the carrier to its original condition so it can go through another cycle of transport.
2. Terminology: Carriers are also variously called "porters,""porting systems,""translocases,""transport systems" and "pumps."
3. Carriers resemble enzymes in some of their properties.
   • They are NOT enzymes, as they do NOT catalyze chemical reactions.
   • They are enzyme-like in the following ways.

     They are specific.

     They have dissociation constants for the transported substances which are analogous to Km of enzymes.

     Transport can be inhibited by specific inhibitors.

     They exhibit saturation, like enzymes do. Diffusion, in contrast, is not saturable, and its rate increases with increasing concentration.

4. A general model for transport is that the carrier is a protein which changes conformation during the transport process.
5. Sometimes carriers move more than one molecule simultaneously. Nomenclature:
   • Uniport: a single molecule moves in one direction.
   • Symport: two molecules move simultaneously in the same direction.
   • Antiport: Two molecules move simultaneously in opposite directions.

Passive mediated transport, or facilitated diffusion.

1. The characteristics of a carrier operating by passive mediated transport.
   • Faster than simple diffusion
   • Movement is down the concentration gradient only (like diffusion)
   • No energy input is required -- the necessary energy is supplied by the gradient.
   • The carrier exhibits

     specificity for the structure of the transported substance

     saturation kinetics

     specific inhibitability

2. Examples of passive mediated transport.
   • Glucose transport in many cells.

     A uniport system

     Can be demonstrated by the fact that adding substances with structures that resemble the structure of glucose can inhibit glucose transport specifically.

     It is specific for glucose. The K_m for glucose is 6.2 mM (a value in the neighborhood of the blood concentration of glucose, 5.5 mM) The K_m for fructose is 2000 mM

     The transport process involves attachment of glucose outside the cell. Conformational change of the carrier protein. Release of the glucose inside the cell. There is no need to change K_m for glucose, since the glucose concentration in the cell is very low.

   • Chloride-bicarbonate transport in the erythrocyte membrane. This is catalyzed by the band 3 protein seen previously.

     An antiport system: both ions MUST move in opposite directions simultaneously. The system is reversible, and can work in either direction. Movement is driven by the concentration gradient.

Active mediated transport involves transport against a concentration gradient, and requires energy.

1. There are two sources of energy for active transport.
   • ATP hydrolysis may be used directly.
   • The energy of the Na⁺ gradient may be used in a symport mechanism. The energy of the Na⁺ going down its gradient drives the movement of the other substance. But since the Na⁺ gradient is maintained by ATP hydrolysis, ATP is the indirect source of energy for this process.
2. The characteristics of a carrier operating by active transport.
   • Can move substances against (up) a concentration gradient.
   • Requires energy.
   • Is unidirectional
   • The carrier exhibits

     specificity for the structure of the transported substance

     saturation kinetics

     specific inhibitability

3. How can the substance be released from the carrier into a higher concentration than the concentration at which it bound in the first place?
   • The affinity of the translocase for the substance must decrease, presumably by a conformational change of the translocase.
   • This process may require energy in the form of ATP.
4. Examples of active mediated transport.
   • Ca⁺⁺ transport is a uniport system, using ATP hydrolysis to drive the Ca⁺⁺ movement. There are two Ca⁺⁺ translocases of importance.
     • In the sarcoplasmic reticulum, important in muscle contraction.
     • A different enzyme with similar activity in the plasma membrane.
   • The Na⁺-K⁺ pump (or Na⁺-K⁺ ATPase).
     • An antiport system.
     • Importance: present in the plasma membrane of every cell, where its role is to maintain the Na⁺ and K⁺ gradients.
     • Stoichiometry: 3 Na⁺ are moved out of the cell and 2 K+ are moved in for every ATP hydrolyzed.
     • Specificity: Absolutely specific for Na⁺, but it can substitute for the K⁺.
     • The structure of the Na⁺-K⁺ pump is a tetramer of two types of subunits, alpha₂beta₂. The beta-subunit is a glycoprotein, with the carbohydrate on the external surface of the membrane.
     • The Na⁺-K⁺ ATPase is specifically inhibited by the ouabain, a cardiotonic steroid. Ouabain sensitivity is, in fact, a specific marker for the Na⁺-K⁺ ATPase.
     • The proposed mechanism of the Na⁺-K⁺ ATPase shows the role of ATP in effecting the conformational change.
       • Na⁺ attaches on the inside of the cell membrane.
       • The protein conformation changes due to phosphorylation of the protein by ATP, and the affinity of the protein for Na⁺ decreases.
       • Na⁺ leaves.
       • K⁺ from the outside binds.
       • K⁺ dephosphorylates the enzyme.
       • The conformation now returns to the original state.
       • K⁺ now dissociates.
   • Na⁺ linked glucose transport is found in intestinal mucosal cells. It is a symport system; glucose is transported against its gradient by Na⁺ flowing down its gradient. Both are transported into the cell from the intestinal lumen. Na⁺ is required; one Na⁺ is carried with each glucose. The Na⁺ gradient is essential; it is maintained by the Na⁺-K⁺ ATPase.
   • Na⁺ linked transport of amino acids, also found in intestinal mucosal cells, works similarly. There are at least six enzymes of different specificity that employ this mechanism. Their specificity is as follows.

     Short neutral amino acids: ala, ser, thr.

     Long or aromatic neutral amino acids: phe, tyr, met, val, leu, ile.

     Basic amino acids and cystine: lys, arg, cys-cys.

     Acidic amino acids: glu, asp

     Imino acids: pro and hypro

     Beta-amino acids: beta-alanine, taurine.

Membrane receptors

Cell-cell communication is by chemical messenger.

1. There are four types of signals.
   • Nerve transmission
   • Hormone release
   • Muscle contraction
   • Growth stimulation
2. There are four types of messenger molecules.
   • steroids
   • small organic molecules
   • peptides
   • proteins
3. The messenger may interact with the cell in either of two ways.
   • Entry into the cell by diffusion through the cell membrane (the steroid hormones do this).
   • Large molecules or charged ones bind to a receptor on the plasma membrane.
4. The events associated with communication via these molecules may include the following.
   • Primary interaction of the messenger with the cell (binding by a receptor).
   • A secondary event, formation of a second messenger. (this is not always found).
   • The cellular response (some metabolic event).
   • Termination (removal of the second messenger).

Messenger molecules which diffuse into the cell -- example: steroid hormones.

1. Steroids are lipid soluble, and can diffuse through the plasma membrane.
2. Cells which are sensitive to steroid hormones have specific receptor proteins in the cytosol or nucleus which bind the steroid.
3. The receptor-hormone complex then somehow causes changes in the cell's metabolism, typically by affecting transcription or translation.
4. The mechanism of termination is unclear, but involves breakdown of the hormone.

Plasma membrane receptors.

1. Membrane receptors bind specific messenger molecules on the exterior surface of the cell. Either of two types of response may occur.
   • Direct response: binding to the receptor directly causes the cellular response to the messenger.
   • Second messenger involvement: Binding to the receptor modifies it, leading to production of a second messenger, a molecule that causes the effect.
   • In each case messenger binding induces a conformational change in the receptor protein. Binding of the messenger resembles binding of a substrate to an enzyme in that there is

     a dissociation constant

     inhibition (by antagonists) which may be competitive, noncompetitive, etc.

2. A variety of messengers can bind to various tissues.
   • Various cellular responses may occur, depending on the tissue.
   • Either positive or negative responses may occur, even in the same tissue, depending on the type of receptor.
3. The response of a cell to a messenger depends on the number of receptors occupied.
   • A typical cell may have about 1000 receptors.
   • Only a small fraction (10%)of the receptors need to be occupied to get a large (50%) response.
   • Receptors may have a dissociation constant of about 10 exp -11; this is the concentration of messenger at which they are 50% saturated. Thus very low concentrations of messengers may give a large response.

The acetylcholine receptor of nervous tissue exemplifies a direct response type of receptor.

1. The receptor is a complex pentameric protein which forms a channel through the membrane.
2. Mechanism of action.
   • Binding of acetylcholine, a small molecule, at the exterior surface causes the channel to open. (Binding)
   • Na⁺ and K⁺ flow through the channel, depolarizing the membrane. (Response)
   • The esterase activity of the receptor then hydrolyses the acetylcholine, releasing acetate and choline, and terminating the effect. (Recovery)
   • The process can now be repeated.

Some receptors involve second messengers.

Sometimes the binding of an effector to a receptor leads to the formation of an intracellular molecule which mediates the response of the effector.

1. Definition: This intracellular mediator is called a second messenger.
2. Effect of second messenger formation: Since a receptor usually forms many molecules of second messenger after being stimulated by one molecule of the original effector, second messenger formation is a means of amplifying the original signal.
3. The formation and removal of the second messenger can be controlled and modulated.

Cyclic AMP (cAMP) is a second messenger that mediates many cellular responses.

1. Structure of cAMP: an internal (cyclic) 3', 5'-phosphodiester of adenylic acid.
2. The mechanism of action of cAMP is to activate an inactive protein kinase.
   • Animated activation sequence.
   • Since an active protein kinase which acts on many molecules of its substrate is produced, this process is an amplification of the original signal.
   • Since the protein kinase is activated by cAMP it is called protein kinase A.

3. cAMP is synthesized by the enzyme, adenyl cyclase.
   • The reaction ATP < -> cAMP + PP_i is reversible, but subsequent hydrolysis of the PP_i

     PP_i + H₂O -> 2 P_i

     draws the reaction forward and prevents reversal.

   • Adenyl cyclase is an enzyme, and therefore it is also part of the amplification system.
   • cAMP is degraded by cAMP phosphodiesterase. cAMP + H₂O -> AMP
4. Adenyl cyclase is controlled by two membrane protein complexes, G_s and G_i.
   • G-proteins are a class of proteins that are so named because they can react with GTP. There are G-proteins in addition to the ones under consideration here.
   • G_s and G_i are so named because they stimulate and inhibit, respectively, adenyl cyclase.
5. The action of the G-proteins.
   • Structure: G-proteins are complexes of three different subunits, alpha, beta and gamma. Beta and gamma are similar in the G_s and G_i proteins. The alpha-subunits are different, and are called alpha_s and alpha_i, respectively.
   • Mechanism: Receptor-messenger interaction stimulates binding of GTP to the alpha-subunits. The alpha-subunit with its bound GTP then dissociates from the beta-gamma complex. The alpha-subunit with its bound GTP then acts on adenyl cyclase. alpha_s-GTP stimulates adenyl cyclase. alpha_i-GTP inhibits adenyl cyclase.
6. Termination of the signal occurs at several levels.
   • The alpha-subunit of the G-protein has GTPase activity. After it cleaves the GTP it reassociates with the beta-gamma complex to form the original trimer.
   • cAMP already formed is cleaved by cAMP phosphodiesterase.
   • The hormone gradually and spontaneously dissociates from the receptor.

Inositol triphosphate (IP₃) and diacylglycerol (DG) are also second messengers.

1. Animated activation sequence.
2. IP₃ and DG are synthesized by the enzyme, phospholipase C, which has phosphatidylinositol 4,5-bisphosphate (PIP₂) phosphodiesterase activity. PIP₂ is a normal minor component of the inner surface of the plasma membrane.
3. The phosphodiesterase is controlled by a G-protein in the membrane, which activates the phosphodiesterase.
4. Mechanism: IP₃ and DG have separate effects.
   • IP₃ releases Ca⁺⁺ from the endoplasmic reticulum. The Ca⁺⁺ then activates certain intracellular protein kinases.
   • DG activates protein kinase c, a specific protein of the plasma membrane.
   • Note that both IP₃ and DG activate protein kinases, which in turn phosphorylate and affect the activities of other proteins.
5. Termination of the signal occurs at several levels.
   • IP₃ is hydrolyzed.
   • Ca⁺⁺ is returned to the endoplasmic reticulum or pumped out of the cell.
   • The GTPase activity of the G-protein hydrolyses the GTP, terminating the activity of the phospholipase C.
6. Many systems respond to changes on IP₃ and DG. Be aware of the large number of systems affected.

Insulin and growth factor receptors.

The insulin receptor exemplifies receptors for which no second messenger has yet been identified.

Structure: The insulin receptor is a tetramer with two kinds of subunits, alpha and beta. Disulfide bridges bind them together.

The mechanism of signal transmission is unclear.

Many of the cellular responses are well known, e.g.

1. Glucose transport
2. Protein phosphorylation -- Insulin and many growth factors activate a protein kinase which phosphorylates a tyrosyl residue in the target proteins, including the receptor itself.
   • The phosphorylation of tyrosyl residues is unusual; usually seryl or threonyl residues become phosphorylated.
   • The significance of this type of phosphorylation is unknown.

Termination of the insulin and certain growth factor signals involves internalization and degradation of the hormone within the cell.

1. The receptor-insulin complex migrates to a region of the plasma membrane with the protein clathrin coating its inner surface.
2. This region forms a "coated pit," a region that invaginates and pinches off, forming an intracellular "coated vesicle."
3. The coated vesicle fuses with a lysosome; the lysosomal proteases degrade the hormone specifically, leaving the clathrin and the receptor unharmed.
4. The receptor and clathrin recycle, and are returned to the plasma membrane.

Return to the NetBiochem Welcome page.

jb

Last modified 1/5/95

Drinking Water Filter

SUMMARY OF THE INVENTION

In view of the foregoing, it is a primary object of the subject invention to provide an improved water filter used for various household uses. Also, the water filter can be used in commercial and industrial applications where treated drinking, cooking and washing water is desired or required. The water filter provides a consumer with protection against major water contaminants found in municipal water supplies.

Another object of the invention is the water filter removes the contaminants in the water to below E.P.A. recommended minimum levels.

Yet another object of the invention is the water filter is designed to remove large and small sediments in the water. Also, the filter removes chlorine, trihalomethanes, hydrogen sulfide, pesticides, herbicides, toxic heavy metals, (such as lead, organic mercury, organic arsenic and others), cysts, protozoa, (including giardia and cryptosporidium), cancer-causing organic pollutants, micro-organisms and other foreign particles and organisms. The subject invention gives treated water a sparkling clarity by screening material out of the water down to a one micron in size.

Still another object of the invention is the filter is designed to raise the water's pH, thereby lowering acidity and increasing alkalinity, which is recommended by many nutritionists.

A further object of the water filter is no plumbing is required in its use. The water filter is received in a filter housing which is attached to a standard water faucet. The filter housing can be disposed on a counter top for household use. Also, the water filter housing can be attached to a water supply line and mounted under a kitchen sink.

Another object of the invention is the water filter costs pennies per gallon, is compact and space saving in design and eliminates the need to buy, lift and carry heavy water bottles. The water filter has a filter life of treating 1500 gallons of tap water, which is a typical one year average drinking and cooking water use of a family of four. The water filter includes a replaceable filter cartridge which can be quickly and easily replaced.

The filter includes a cylindrical filter cartridge with a number of filter layers therein. The filter cartridge is adapted for receipt in a water filter housing connected to a municipal water supply. The filter cartridge includes an upper filter cap with water inlet in fluid communication with a tap water supply to the filter housing. The upper filter cap is received inside an open top portion of the cartridge. The cartridge also includes a lower filter cap with a water outlet. The lower filter cap is received inside an open bottom portion of the cartridge.

The cartridge further includes a plurality of filter pads which may be used as dividers between different layers of filtration material and along a length of the cartridge. The filter pads are designed to remove large and small sediments in the water from 1 to 100 microns in size and greater when the water is introduced through the cartridge.

In an upstream upper portion of the cartridge is layer of a granulated zinc and copper alloy. The zinc and copper alloy is known in the trade by a brand name of KDF-55. The zinc and copper alloy is used for removing chlorine and some heavy metals in the water. Also, the alloy is an excellent bacteriostat for reducing bacteria in the water.

In a center portion of the filter cartridge is a layer of granulated activated carbon. The activated carbon is used for removing chlorine, odor and color from the water being filtered. Also, the activated carbon removes organic contaminants such as pesticides, herbicides, arsenic, mercury and trihalomethanes, a cancer-causing organic pollutant.

Downstream from the layer of granulated activated carbon is a layer of a granulated ion exchange resin. The ion exchange resin has an exceptional affinity for lead and removes this contaminant to below minimum E.P.A. standards.

In a downstream bottom portion of the cartridge is a layer of granulated calcite. The calcite may be used in the filter to raise the water's pH. This feature lowers the acidity of the water and increases the alkalinity, which many nutritionists recommend.

The last stage of the filter is a one micron absolute depth filter material made of polypropylene or like material. The one micron filter material screens out cysts and protozoa, which includes giardia and cryptosporidium. Also, by filtering the water through the one micron filter material, the water is given a sparkling clarity.

These and other objects of the present invention will become apparent to those familiar with the water filters and water filtration equipment when reviewing the following detailed description, showing novel construction, combination, and elements as herein described, and more particularly defined by the claims, it being understood that changes in the embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing illustrates complete preferred embodiment of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which:

FIG. 1 is a perspective view of the subject water filter with the filter cartridge in an upright position. A portion of a cartridge housing has been cutaway to expose and illustrate the various granular materials used in filtering the water to be treated. Arrows are shown at the top of the cartridge to illustrate the incoming unfiltered water. Also, additional arrows are shown at the bottom of the filter cartridge illustrating discharged treated water.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, a perspective view of the subject water filter is shown having a general reference numeral 10. The water filter 10 includes a cylindrical hollow filter cartridge 12 shown in an upright position. The cartridge 12 is adapted for receipt inside a filter housing which is connected to a tap water supply line. The filter housing and the water line are not shown in the drawings. The filter housing may be a free standing unit for receipt on top of a kitchen counter top or may be mounted under a kitchen sink or like installation.

The cartridge 12 includes a cartridge housing 14. The cartridge housing 14 includes an upstream upper portion 16, a center portion 18 and a downstream lower portion 20. A portion of the cartridge housing 14 in FIG. 1 has been cutaway to expose and illustrate the various layers of granular materials and filter pads used in filtering the water as it flows therethrough.

Also, the cartridge 12 includes an upper filter cap 22 with a water inlet 24. The water inlet 24 is in fluid communication with the tap water supply line. The upper filter cap 22 is received inside an open top portion 26 of the cartridge housing 14. The cartridge 12 also includes a lower filter cap 28 with a water outlet. The lower filter cap 28 is received inside an open bottom portion 30 of the cartridge housing 14. The water outlet is centered on the lower filter cap 28 and is hidden in this drawing and therefore not shown. In this drawing, arrows 32 are shown at the top of the cartridge 12 to illustrate the incoming unfiltered water from the water supply line. Also additional arrows 34, illustrating the discharged treated water, are shown leaving the water outlet in the lower filter cap 28.

The filter cartridge 12 further includes a plurality of filter pads which may be used as dividers between different layers of filtration material and along a length of the cartridge housing 14. A first filter pad 36 is designed to remove large solids and sediments such as rust. The pad 36 is typically a 100 micron sponge filter but can be in a range of 50 to 150 microns for screening large particles and floating solids in the unfiltered water.

In the upstream upper portion 16 of the cartridge 12 and below the pad 36 is layer of a granulated zinc and copper alloy 38. The zinc and copper alloy 38 is known in the trade by a brand name of KDF-55. The zinc and copper alloy 38 is used for removing chlorine and some heavy metals in the water. Also, the alloy 38 is an excellent bacteriostat for keeping bacteria from growing inside the cartridge 12.

Disposed below the layer of alloy 38 is a second filter pad 40. The second filter pad 40 is typically a 10 micron felt pad for removing smaller floating solids in the water. The pad 40 can be in a range of 5 to 20 microns for screening small particles out of the water.

In the center portion 18 of the cartridge 12 and below the second filter pad 40 is a layer of granulated activated carbon 42. The activated carbon 42 is used for removing chlorine, odor and color from the water being filtered. Also, the activated carbon 42 removes organic contaminants such as pesticides, herbicides, arsenic, mercury and trihalomethanes, a cancer-causing organic pollutant.

Disposed below the layer of activated carbon 42 is a third filter pad 44. The third filter pad 44 is typically a 10 micron felt pad for removing fine sediment in the water. The pad 44, similar to the second pad 40, can be in a range of 5 to 20 microns for screening small and fine particles out of the water.

Downstream from the layer of granulated activated carbon 42 and below the third filter pad 44 is a layer of a granulated ion exchange resin 46. The ion exchange resin 46 has an exceptional affinity for lead and removes this contaminant to below minimum E.P.A. standards.

Disposed below the layer of ion exchange resin 46 is a fourth filter pad 48. The fourth filter pad 44 is typically a 10 micron felt pad for removing fine sediments in the water. The pad 48, similar to the second and third pads 40, 44, can be in a range of 5 to 20 microns for screening additional small and fine particles out of the water.

In the downstream bottom portion 20 of the cartridge 12 is a second layer of granulated activated carbon 42. The second layer of activated carbon 42 provides additional protection in removing chlorine, odor, and cancer-causing organic pollutants from the water.

Disposed below the second layer of activated carbon 42 is a fifth filter pad 50. The fifth filter pad 44 is typically a 10 micron felt pad for removing fine sediment in the water. The pad 48, similar to the other above mentioned felt pads and can be in a range of 5 to 20 microns for screening additional small and fine particles out of the water.

Below the fifth filter pad 44 is a layer of granulated calcite 52. The calcite 52 may be used in the filter 10 to raise the water's pH. This feature lowers the acidity of the water and increases the alkalinity.

The last stage of the water filter 10 is a one micron absolute depth final filter 54. The final filter 54 is made of cellulose or like material. The one micron final filter 54 screens out cysts and protozoa. Also, by filtering the water through the one micron final filter 54, the water is given a sparkling clarity. The final filter 54 is disposed above the lower filter cap 28.

While the invention has been shown, described and illustrated in detail with reference to the preferred embodiments and modifications thereof, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention as claimed, except as precluded by the prior art.

AIR FILTRATION

AIR FILTRATION

---

THEORY AND BACKGROUND

Airborne Particle Characteristics

Airborne contaminants pose a constant threat to our environment. Man and nature both foul the air with particulate and gaseous pollutants. Despite efforts to control emission of these pollutants, the air around most large cities still contains billions of particles per cubic foot of air. A great many of these are dangerous to plant and animal life. Clean air is dependent upon a reduction of these particulate levels.

The following information is provided to give a basic understanding of the characteristics of particulate matter.

Particulate Matter

For our purposes , particles are defined as bodies with:

1. Definite physical boundaries in all directions.
2. Diameters ranging from 0.001 micron to 100 microns.
3. Liquid or solid phase material characteristics.

A micron, or micrometer, is a measure of length in the metric system. One micron equals one-millionth (1/1,000,000 or 0.000001) of a meter. In English units one micron equals 1/25,400 inch.

EXAMPLES:

1. 1 inch = 25,400 microns (or 0.000039411 = 1 micron).
2. Eye of needle (1/32 inch) = 749 microns.
3. The dot of an "i" (1/64 inch) = 397 microns.

Particle Visibility

The ability to see an individual particle depends on the eye itself, the intensity and quality of light, the background and the type of particle. The particles seen on furniture or floating in a ray of sunshine are in the range of 50 microns or larger, although 10 micron particles can be seen under favorable conditions. A beam of light is visible due to the light scattering effects produced by a multitude of particles present in the air. In this manual, 10 microns has been chosen as a conservative dividing line between larger. visible and smaller, invisible particles.

Particles smaller than 10 microns are visible under a microscope. Electron microscopes can resolve particles down to 0.001 micron. Particles as small as 0.01 micron are demonstrably removable by an electronic air cleaner although theoretically it will remove particles down to 0.001 micron.

The majority of invisible particles are 3 microns in diameter and smaller. If these smaller particles are present in vast numbers, they are usually visible as a pollutant due to their light scattering quality. For instance, a wisp of cigarette smoke is actually composed of tiny particles (0.01 to 1 micron) which are too small to be seen individually. As soon as the smoke particles disperse, they are no longer visible.

Visible particles (less than 10% of the total airborne particles by count) tend to settle on horizontal surfaces of furniture, floors and shelves where they can be removed by a dust cloth, mop or vacuum cleaner. Invisible particles can deposit on vertical as well as horizontal surfaces. In industry, this contributes to the soil and grime that collects on walls, windows, machinery and clothing, forming potential health hazards as well as maintenance problems.

Particle Weight and Density

In ambient air, 99% of airborne particles by count are less than 1 micron but contribute only 20% of the total particle weight. The remaining weight comes from a rather small number of particles up to 100 microns in size. Industrial processes generate particulate, adding to material already suspended in the air. The "smoke" they generate usually consists of high concentrations of particles less than 10 microns (typically, 60% are less than 2 microns).

Standard filter media can remove particles above 10 microns very effectively. As particle size decreases to 5 microns, 2 microns and on into the sub-micron range, mechanical particulate removal systems become increasingly expensive to operate at high efficiency. It is in this range that the electronic air cleaner performs best, yielding high collection efficiency at a very low expenditure of energy.

Particle Settling Factor

The rate at which particles of the same density (same weight per volume) settle out of the air is an important factor affecting the performance of air cleaning equipment. In a room with an eight foot ceiling, the time necessary for particles to settle out of the air can be dramatic.

Particle Settling Times

Many 10 micron and larger particles settle out of the air before they reach the air cleaner. About 5 to 10% (75 to 90% by weight) settle in the rooms and never reach the air cleaner. Particles less than 1 micron have masses so small that gravity is seemingly neutralized. Their settling velocities are so low that they are easily affected by air movement from hot working machinery and plant circulation systems. These particles are also subject to Brownian motion, i.e., erratic movement of particles in a fluid (in this case, air). Brownian effects become dominant on particles less than 0.3 micron in size, where their random motion keeps them almost indefinitely suspended in the air. By continuously recirculating plant air through an air cleaner, or series of cleaners, a high efficiency of small particle removal can be attained. By capturing the particles at the generation source, an even higher efficiency can be achieved, usually with less air cleaner capacity.

Respirable Fraction

Industrial hygienists are concerned about airborne particulates and their effect on the welfare of workers. The human body is a marvelous filter mechanism, but vulnerable to heavy concentrations of small particles. Some particles are particularly dangerous to the human anatomy since they can become trapped for long periods of time, or even permanently.

Some particle size ranges have been identified as areas of special attention. Particles 10 microns and below fall into the "inhalable fraction" range, i.e., those particles small enough to pass through the body's standard filtration mechanisms and deposit. Particles below about 2.5 microns constitute the "respirable fraction", i.e., that percentage of particles which can be trapped in the human lung or even find their way into the blood stream. Potential chemical reactivity, surface reactivity and immunological effects make these particulates extremely dangerous. Two stage electrostatic precipitators, with peak efficiencies in the inhalable and respirable fraction range, are useful tools in industrial particulate emission control.

Particulate Adhesion and Soiling Effects (Housekeeping)

Particles under 1 micron in size are suspended in the air until they deposit on some type of surface. They deposit on vertical and underside surfaces such as walls and ceilings, as easily as they do on floors. Once deposited, they are imbedded or attached to that surface by molecular adhesion so that manual cleaning is the only way to remove them. Examples of this include oily residue on machinery, discoloration and dirt build-up on walls and light fixtures, and thick layers of powdery residue in welding shops.

The Electronic Air Cleaner

The electronic air cleaner is technically referred to as an electrostatic precipitator. An electrostatic precipitator is a device which ionizes, or charges, then collects, particulate suspended in a gas stream. The term "electrostatic" is used even though the mechanism of removal is dynamic rather than static. This term evolved because of the close relationship between the physical behavior of the device and the general field of static electricity that exists in it. Credit is given to two modem day pioneers, F. G. Cottrell in the United States and Sir Oliver Lodge in Great Britain, for developing the single stage precipitator for particulate removal in industries such as blast furnaces, reverberatory furnaces and power plants. In 1933, Dr. Gaylord Penney developed the two-stage electrostatic precipitator-the type most commonly used today in commercial and industrial process applications.

Theory of Electrostatic Particle Attraction

Common electrical phenomena, such as a comb attracting bits of paper or dry clothes that cling to the body, (occurrences normally ascribed to static electricity), illustrate the attractive force employed in electronic air cleaners. Under normal conditions, particles in the air tend not to exhibit visible attraction to one another because they are electrically "neutral," carrying little, if any, charge.

In the example of the comb and bits of paper the rubbing of the comb changes the electrical balance, or polarity," and causes the comb to attract the paper. In the same manner, an electronic air cleaner actively alters the electrical balance of particles in the air by imparting a high positive charge to those particles. The particles' tendency to be repelled by other positive surfaces and to be attracted by negative surfaces is radically intensified. These phenomena occur because the materials involved have different electrostatic charges, or polarities, with respect to one another. However, none of the above exhibit a visible attraction for any of the others without special treatment. They are usually electrically neutral because each one tends to be balanced electrically and has very little, if any, charge. Rubbing the objects disturbs the electrical balance and creates a slight mutual attraction between them.

How Electronic Air Cleaners Work

A two-stage electrostatic precipitator is constructed in two sections-a charging, or ionizing, section and a collecting section. The charging section contains a series of fine wires suspended between metal plates; the collecting section is a series of parallel, flat metal plates spaced about a quarter inch apart. The entrained particles are first given an electrical charge by the ionizer. They are then collected on plates which have an opposite charge in the collection cell.

The Ionizing Section

When observed in darkness, a pale violet glow appears around the fine wires of the ionizer when it is operating. This is a visible indication of a corona discharge in the air immediately adjacent to the wires. It is in the area of this discharge that the electric charges are produced for the particles to be collected. The intense electrical activity which occurs in this area may be explained as it applies to the charging of particles in an electronic air cleaner. According to electrostatic theory, when a continuous DC voltage is applied to a fine wire suspended between grounded metal plates (a large surface in relation to the wire), a nonuniform electrostatic field is formed in the inter-electrode space (on both sides of the wire between the grounded plates). The field is said to be non-uniform because it is very strong near the wire, decreasing rapidly, as distance from the wire increases, to a relatively low value at the surface of the grounded plates. By increasing the voltage on the wire, field strength is proportionately increased. Eventually, depending upon wire size, wire shape and distance from wire to plate, corona starting conditions are reached and air (gas molecules) near the wire is forced to undergo an electrical change

A molecule is the smallest portion of any substance that can exist and still retain the chemical characteristics of the substance. Each molecule includes protons that carry a positive electrical charge and electrons that carry a negative electrical charge. The negative charges of the electrons are all of the same value and in an electrically neutral molecule their sum equals the sum of the positive charges of the protons in the molecule. But if one or more of the electrons is knocked out of the molecule, for instance by collision with a foreign electron, the molecule is left with a surplus of positive charge and then is called a positive ion. If the positive ion is in an electrostatic field, it will be propelled toward the negative side of the field. The freed electron will be propelled toward the positive side of the field. The propelling force will be proportional to the gradient of field intensity. "Free" electrons (those not attached to atoms) exist everywhere, even in a vacuum. Within the non-uniform electrostatic field in an electronic air cleaner, free electrons are accelerated toward the positively charged wire. The velocity becomes very great as they pass through the increasingly higher fie!d intensity in approaching the wire. On their way, many free electrons strike air molecules and knock other electrons out of them. The dislodged electrons then accelerate toward the positive wire, in turn knocking more electrons free from other molecules. In this way a vast number of positive ions are created and they move rapidly toward the grounded plates. The electrons attracted to the wire tend to neutralize the positive charge on the wire, but are prevented from doing so by the continuously supplied current from a highvoltage power supply. In the process, electrons pass through the wire and the power supply circuit to the negatively charged plates, where they again combine with positive ions and prevent the neutralizing of the negative charge on the grounded plates.

Dense clouds of charged air molecules, or ions, are diffused and accelerated away from the wire (toward the grounded plates) by electrostatic field and molecular forces. A dense cloud of air ions exists in the interelectrode space across the inlet to the electronic air cleaner. These ions attach to particulate and cause the particulate to be removed by the field. The disruption of the molecules in the process of creating the positive ions causes energy to be radiated. Some of this energy is in the visible light spectrum producing a visible corona around the wire.

The Collecting Section

While some collecting occurs in the ionizer of a two-stage electronic air cleaner, most takes place in the separate collecting section, or second stage. The collecting section is comprised of a series of flat metal plates set parallel to the airflow through the air cleaner. Their spacing is a design consideration that varies somewhat from air cleaner to air cleaner, but is usually about a quarter-inch. To make the collector work, a high voltage DC source is applied to every other plate. The alternate plates are grounded so that there is a high voltage difference between plates.

The following examines the collecting process with reference to just one set of two adjacent collecting plates. (This applies to a series of plates as well.) A uniform electric force field is produced between the two plates when a voltage is applied to them, creating a uniform distribution of electrons (negative charge) on the surface of one plate opposite an equal and uniformly distributed deiciency of electrons (positive charge) on the other. The voltage gradient is uniform throughout this field.

A single, positively charged particle entering such a field is acted upon by a force, the sum of all the attracting and repelling forces due to the interaction of the uniformly distributed charges on the plates and the charge on the particle itself. These forces accelerate the particle toward the negative (grounded) plate. Likewise, a negatively charged particle is forced toward the positive plate. As a design consideration, it is important to note that the amount of force on the particle depends on the amount of charge imparted on the particle in the ionizing section, the voltage applied to the cell plates, and the space between the plates. These relationships, along with the velocity of the airstream itself, account for significant differences in efficiencies between various types and brands of electronic air cleaners.

Because of the uniform characteristics, the amount of force on the particle is the same whether the particle is near the negative plate, positive plate or anywhere in between. If no other force is acting on the particle, it is accelerated (constant rate of increase in velocity) in the direction of the negative plate. The force on a small particle can be in excess of 1,000 times the force of gravity.

Other forces also act on this particle as it passes between the collecting plates in an air cleaner. Among them are the resistance of the airstream, the repelling and attracting forces between it and other particles, gravity, inertia and others. Any or all of these forces may affect the movement of the particle toward the collecting plates. Although the actual paths of particles in the collector vary considerably, the component of force (the electrostatic field force) toward the plates is great enough in relation to the downstream component to transport the particles along a nearly diagonal path to the collector plates.

The air cleaner designer uses this information to increase the effectiveness of the collecting section. He might lengthen the plates (in the direction of airflow) so that the particles have more time to migrate to them. He might increase the voltage, decrease the space between plates, decrease velocity or increase the charge on the particles by strengthening the electrostatic field in the charging section.

Other Air Cleaner Components

To maintain maximum efficiency, the air entering the cleaner must be equally distributed across the ionizer and collecting cell. This is accomplished with pre and afterfilters. The prefilter diffuses the air across the ionizer as it enters the air cleaner. It traps larger particles that could short out the active components and allows the precipitator to collect the small to submicron particles to which it is best suited. The afterfilter also aids in equalizing air distribution.

Measuring Efficiency

Finding an accurate test procedure and evaluation method has occupied filter manufacturers for over 20 years. The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Technical Advisory Committee on Air Cleaning has been establishing test procedures since the early 1930's.

Lack of standardization has resulted in line after line of filtering products which are almost perfect according to the manufacturer's own ratings. From published efficiency ratings, it is often only possible to find differences among filters in the last 1/10 of 1%. In recent years, there has been a more realistic approach to advertised ratings of air cleaning devices due, in part, to the emergence of electronic air cleaners and other new filter products.

Ozone

Ozone is a pungent, colorless, toxic, unstable form of oxygen. Its chemical symbol is O3 It is formed in nature as well as by artificial means. It is usually produced by the discharge of electricity (lightning) in ordinary air or by subjecting air or oxygen to ultraviolet radiation. Normally, it is present in low concentrations wherever there is oxygen. The ozone layer in the stratosphere at an altitude of about 35 to 40 miles has concentrations of 10 to 20 parts of ozone per million (PPM) of air. Normal down drafts and other atmospheric disturbances bring some of this ozone down to the surface of the earth where concentrations seldom exceed a few parts per million.

Ozone generators are devices that produce ozone as a primary function. Electrostatic precipitators, copy machines and arc welders are devices that produce some ozone as a by-product of their intended function.
Ozone can be injurious to health when reaching certain levels. It can have undesirable physiological effects on the central nervous system, heart and vision. The predominant physiological effect is that of irritation to the lungs resulting in pulmonary edema. On the positive side, ozone acts as a deodorizing agent for objectionable odors. It readily oxidizes organic matter and has a variety of uses such as sterilization of water, bleaching and control of fungi in cold storage rooms.

Like many substances, ozone has advantages and disadvantages depending on its intended use and concentrations. Concentrations of ozone, as related to adverse health effects, influence allowable exposure time. High levels of ozone can be tolerated for a short period of time or low levels of ozone for a long period of time.

OSHA (Occupational Safety and Health Administration) has established 0. 1 parts per million (PPM) by volume of air, 0.2 Mg/M3, as the maximum allowable safe concentration of ozone for an 8 hour industrial exposure.

Ozone, being a form of oxygen, mixes with and decomposes in air. Decomposition is more rapid in higher humidity. The amount of ozone, therefore, that will be in the air depends upon the rate of generation versus the rate of decomposition. Another factor affecting the amount of ozone is the dilution of the air. The above statement applies only to an airtight room. The average building today completely exchanges the air 1 to 4 times an hour depending on the insulation, tightness of construction and make-up air systems.

Independent laboratory tests show that some air cleaner generate ozone at an average rate of 0.8 parts per 100 million (PPHM), or 0.008 parts per million (PPM) or less, a figure well below allowable concentrations.

R.A. Mashelkar, F.R.S.

R.A. Mashelkar, F.R.S.

Dr. R.A. Mashelkar was the Director General of Council of Scientific and Industrial Research (CSIR), the largest chain of publicly funded industrial research and development institutions in the world, with thirty-eight laboratories and about 20,000 employees.

Dr. Mashelkar is at present the President of Indian National Science Academy (INSA). He is only the third Indian engineer to have been elected as Fellow of Royal Society (FRS), London in the twentieth century. He was elected Foreign Associate of National Academy of Science (USA) in 2005, only the 8 th Indian since 1863 to be s0 elected. He was elected Foreign Fellow of US National Academy of Engineering (2003), Fellow of Royal Academy of Engineering, U.K. (1996), and Fellow of World Academy of Art & Science, USA (2000). Twenty-three universities have honoured him with honorary doctorates, which include Universities of London, Salford, Pretoria, Wisconsin and Delhi.

In August 1997, Business India named Dr. Mashelkar as being among the 50 path-breakers in the post- Independent India. In 1998, Dr. Mashelkar won the JRD Tata Corporate Leadership Award, the first scientist to win it. In June, 1999, Business India did a cover story on Dr. Mashelkar as "CEO OF CSIR Inc." , a dream that he himself had articulated, when he took over as DG, CSIR in July 1995. On 6 November 2005, he received the Business Week (USA) award of ‘Stars of Asia' at the hands of George Bush (Sr.), the former President of USA.

When Dr. Mashelkar took over as the Director General of CSIR, he enunciated “CSIR 2001: Vision & Strategy” . This was a bold attempt to draw out a corporate like R&D and business plan for a publicly funded R&D institution. This initiative has transformed CSIR into a user focussed, performance driven and accountable organization. This process of transformation has been recently heralded as one of the ten most significant achievements of Indian Science and Technology in the twentieth century.

Dr. Mashelkar has been propagating a culture of innovation and balanced intellectual property rights regime for over a decade. It was through his sustained and visionary campaign that growing awareness of Intellectual Property Rights (IPR) has dawned on Indian academics, researches and corporates. He spearheaded the successful challenge to the US patent on the use of turmeric for wound healing and also the patent on Basmati rice. These landmark cases have set up new paradigms in the protection of India's traditional knowledge base, besides leading to the setting up of India's first Traditional Knowledge Digital Library. In turn, at an international level, this has led to the initiation of the change of the International Patent Classification System to give traditional knowledge its rightful place. As Chairman of the Standing Committee on Information Technology of World Intellectual Property Organization (WIPO), as a member of the International Intellectual Property Rights Commission of UK Government and as Vice Chairman on Commission in Intellectual Property Rights, Innovation and Public Health (CIPIH) set up by World Health Organization (WHO), he brought new perspectives on the issue of IPR and the developing world concerns.

In the post-liberalized India, Dr. Mashelkar has played a critical role in shaping India's S&T policies. He was a member of the Scientific Advisory Council to the Prime Minister and also of the Scientific Advisory Committee to the Cabinet set up by successive governments. He has chaired ten high powered committees set up to look into diverse issues of higher education, national auto fuel policy, overhauling the Indian drug regulatory system, dealing with the menace of spurious drugs, reforming Indian agriculture research system, etc. He has been a much sought after consultant for restructuring the publicly funded R&D institutions around the world; his contributions in South Africa, Indonesia and Croatia have been particularly notable.

Dr. Mashelkar has won over 40 awards and medals, which include S.S. Bhatnagar Prize (1982), Pandit Jawaharlal Nehru Technology Award (1991), G.D. Birla Scientific Research Award (1993), Material Scientist of Year Award (2000), IMC Juran Quality Medal (2002), HRD Excellence Award (2002), Lal Bhadur Shastri National Award for Excellence in Public Administration and Management Sciences (2002), World Federation of Engineering Organizations (WFEO) Medal of Engineering Excellence (2003) by WFEO, Paris, Lifetime Achievement Award (2004) by Indian Science Congress, the Science medal (2005) by TWAS, the Academy of Science for the Developing World, Asutosh Mookherjee Memorial Award (2005) by Indian Science Congress, etc.

The President of India honoured Dr. Mashelkar with Padmashri (1991) and with Padmabhushan (2000), which are two of the highest civilian honours in recognition of his contribution to nation building.

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Lessons Of life

Allow Your Own Inner Light to Guide You

There comes a time when you must stand alone.

You must feel confident enough within yourself to follow your own dreams.

You must be willing to make sacrifices.

You must be capable of changing and rearranging your priorities so that your final goal can be achieved.

Sometimes, familiarity and comfort need to be challenged.

There are times when you must take a few extra chances and create your own realities.

Be strong enough to at least try to make your life better.

Be confident enough that you won't settle for a compromise just to get by.

Appreciate yourself by allowing yourself the opportunities to grow, develop, and find your true sense of purpose in this life.

Don't stand in someone else's shadow when it's your sunlight that should lead the way.

I've learned that we don't have to change friends if we understand that friends change.

I've learned that no matter how good a friend is, they're going to hurt you every once in a while and you must forgive them for that.

I've learned that true friendship continues to grow, even over the longest distance. The same goes for true love.

I've learned that you can do something in an instant that will give you heartache for life.

I've learned that it's taking me a long time to become the person I want to be.

I've learned that you should always leave loved ones with loving words. It may be the last time you see them.

I've learned that you can keep going long after you can't.

I've learned that we are responsible for what we do, no matter how we feel.

I've learned that either you control your attitude or it controls you.

I've learned that regardless of how hot and steamy a relationship is at first, the passion fades and there had better be something else to take its place.

I've learned that heroes are the people who do what has to be done when it needs to be done, regardless of the consequences.

I've learned that money is a lousy way of keeping score.

I've learned that my best friend and I can do anything or nothing and have the best time.

I've learned that sometimes the people you expect to kick you when you're down, will be the ones to help you get back up.

I've learned that sometimes when I'm angry I have the right to be angry, but that doesn't give me the right to be cruel.

I've learned that just because someone doesn't love you the way you want them to doesn't mean they don't love you with all they have.

I've learned that maturity has more to do with what types of experiences you've had and what you've learned from them, and less to do with how many years you have lived.

I've learned that it isn't always enough to be forgiven by others. Sometimes you have to learn to forgive yourself.

I've learned that no matter how bad your heart is broken the world doesn't stop for your grief.

I've learned that our background and circumstances may have influenced who we are, but we are responsible for who we become.

I've learned that just because two people argue, it doesn't mean they don't love each other And just because they don't argue, it doesn't mean they do love each other.

I've learned that you shouldn't be so eager to find out a secret. It could change your life forever.

I've learned that two people can look at the same thing and see something totally different.

I've learned that your life can be changed in a matter of hours by people who don't even know you.

I've learned that even when you think you have no more to give, when a friend cries out to you you will find the strength to help.

I've learned that credentials on the wall do not make you a decent human being.

I've learned that the people you care about most in life are sometimes taken from you too soon

what is chemcial engineering?

What is Chemical Engineering
	Chemical engineering is a discipline influencing numerous areas of technology. In broad terms, chemical engineers are responsible for the conception and design of processes for the purpose of production, transformation and transportation of materials. This activity begins with experimentation in the laboratory and is followed by implementation of the technology to full scale production. The large number of industries which depend on the synthesis and processing of chemicals and materials place the chemical engineer in great demand. In addition to traditional examples such as the chemical, energy and oil industries, opportunities in biotechnology, pharmaceuticals, electronic device fabrication, and environmental engineering are increasing. The unique training of the chemical engineer becomes essential in these areas whenever processes involve the chemical or physical transformation of matter. For example, chemical engineers working in the chemical industry investigate the creation of new polymeric materials with important electrical, optical or mechanical properties. This requires attention not only to the synthesis of the polymer, but also to the flow and forming processes necessary to create a final product. In biotechnology, chemical engineers have responsibilities in the design of production facilities to use microorganisms and enzymes to synthesize new drugs. Problems in environmental engineering that engage chemical engineers include the development of processes (catalytic converters, effluent treatment facilities) to minimize the release of or deactivate products harmful to the environment. To carry out these activities, the chemical engineer requires a complete and quantitative understanding of both the engineering and scientific principles underlying these technological processes. This is reflected in the curriculum of the chemical engineering department which includes the study of applied mathematics, material and energy balances, thermodynamics, fluid mechanics, energy and mass transfer, separations technologies, chemical reaction kinetics and reactor design, and process design. These courses are built on a foundation in the sciences of chemistry, physics and biology.

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Websites of Different Chemical Engineering Institutes

Assam Engineering College - c/o Guwahati University, Guwahati - 781013

Bokaro Institute of Technology - Dhanbad- 828123

Zakir Hussan College of Engineering and Tech c/o Aligarh Muslim University - Aligarh- 202002

Institute of Technology - c/o Banaras Hindu Univesity, Varanasi - 221005

Central Electrochemical Research Institute - Karaikudi- 623006

Coimbatore Institute of Technology - Coimbatore - 641014

Dr. M.G.R. Engineering College - Chennai- 602101

Dr. Navalar Nedunchezhiyan College of Engineering -Tholudur-606303

S.D.College of Engineering & Technology - Muzaffarnagar- 251001

Dr. Kedar Nath Modi Institute of Engineering and Technology (Affiliated to Choudhry Charan Singh Univerity) - Modinagar- 201204

Harcourt Butler Technological Institute - c/o S. S. J. Maharaj University - Kanpur- 208002

Department of Chemical Engineering &Technology - Punjab University , Chandigarh - 160014

Indian Institue of Technology - INew Delhi - 110016

Chhotu Ram State College of Engineering c/o Guru Jambheshwar University, Sonepat , Murthal - 131039

Institute of Engineering & Technology - c/o Kanpur University, Kanpur - 208024

Indian Institute of Technology -Kanpur- 208016

Bihar Institute of Technology - Dhanbad- 828123

Indira Gandhi Institute of Technology - Dhenkanal , Sarang - 759146

Regional Engineering College - Rourkela - 769008

Pondicherry Engineering College - Pondicherry- 605014

Government Engineering College - Raipur- 492010

Government Engineering College - Ujjain- 456010

Institute of Technology & Management - Gwalior- 474001

Maharana Pratap College of Technology - Gwalior- 474003

Bhai Jaitaji College of Engineering & Tech - Chamkour Sahib, Punjab

Thadomal Shahani Engineering College - Linking Rd, Mumbai.

Shaheed Bhagat Singh College of Engineering & Technology - Ferozepur- 152001

Faculty of Engineering & Technology - c/o Jadavpur University , Calcutta - 700032

Sant Longowal Institute of Engineering & Technology - Longowal - 148106

Beant College of Engineering & Technology - Gurudaspur- 143521

Department of Chemical Engineering and Technology - Punjab

Dr. B.R.Ambedkar Regional Engineering College - Jallandhar- 144027

Indian Institute of Technology -Kharagpur- 721302

University College of Science & Technology - Kolkata - 700009

Dwarkadas J. Sanghiv College of Engineering - Vile Parle (W), Mumbai.

Indian Institue of Technology - IIT Powai ( Mumbai )

Jawahar Lal Darda Institute of Engineering - Yavatmal

Anuradha Engineering College - Buldana - 443201

Bharati Vidyapeeth's College of Engineering - CBD, Navi Mumbai- 400614

Department of Chemical Technology - Matunga, Mumbai.

Dr. Babasaheb Ambedkar Technological University - Lonere- 402103

Jondhale College of Engineering - Dombivli- 421202 ( Maharashtra)

Jawaharlal Nehru Engineering College - Aurangabad- 431003

Konkan Education Societys Engineering College - Raigad - 402107

Parvara Rural College of Engineering - Ahmednagar

S.S.E. Society's College of Engineering & Technology - Akola- 444001

Shivajirao's Jondhale College of Engineering -Thane- 421202

Laxminarayan Institute of Technology - Nagpur- 440010

Maharashtra Institute of Technology -Pune

Mahatma Gandhi Mission's College of Engineering - Navi Mumbai- 410209

Padmabhusan Vasantdada Patil Institute of Tech - Miraj- 416304, Sangli

Shrama Sadhna Trusts's College of Engineering & Techn. - Jalgaon- 425001

Tatyasaheb Kore Institute of Engineering & Technology - Waranganagar- 416113, Kolhapur

RTE Society's Rural Engineering College - Hulkot.i- 582205, Dharwad.

RV. College of Engineering - Bangalore- 560059

Rural Engineering College - Bhalki- 585328

University Department of Chemical Technology - Matunga- 400019 ( Mumbai)

Dayananda Sagar College of Engineering - Bangalore- 560078

Dr. TMA. Pal Foundation - Manipal- 576119

M.S. Ramaiah Institute of Technology - Bangalore- 560054

M.V.J. College of Engineering - Bangalore- 560067

Siddaganga Institute of Technology - Tumkur-572103

Sri Venkateswara University College of Engineering - Tirupati- 517502

University College of Technology - c/o Osmania University , Hyderabad- 500007

Madhav Institute of Technology & Science - Gwalior.

Alagappa College of Technology - c/o Anna University, Chennai- 600025

S.V.E. Society's Rural Engineering College - Bhalki- 585328

Sri Dharmasthala Manjunatheshwara College of Engineering & Technology - Dharwad- 580002

Government Engineering College - Thrisur- 680009

Thangal Kunju Musaliar College of Engineering - Kollam - 691005

Anjalai Ammal Mahalingam Engineering College - Kovilvenni - 614403

Edayathangudi G.S. Pillay Engineering College - Nagapattinam - 611001

Erode Sengunthar Engineering College - Periyar

Faculty of Engineering & Technology - c/o Annamalai University, Annamalainagar- 608002

Indian Institute of Technology - Chennai- 600036

Kongu Engineering College - Perundurai- 638052

Priyadarshini Engineering College - Anna Salai Konamedu Vaniyambadi- 635751

Regional Engineering College - Tiruchirapalli- 620015

Sathyabama Engineering College - Chennai- 600096

Shanmugha College of Engineering -Thanjavur- 613402

Sri Ram Engineering College - Perumalapttu- 602024

Sri Venkateswara College of Engineering - Pennalur Sriperumbudur- 602105

St. Joseph's College of Engineering - Chennai- 600096

Vellore Engineering College - Vellore- 632014

Faculty of Technology & Engineering - Vadodara - 390001

Government Engineering College Gandhinagar - 382027

L.D. College of Engineering - Ahmadabad - 380015

Nirma Institute of Technology c/o Gujarat University - Ahmedabad - 380058

Sarvjanik College of Engineering & Technology c/o South Gujarat University) - Surat- 395001

Birla Institute of Technology & Science -Pilani- 333031

Malaviya Regional Engineering College c/o University of Rajasthan - Jaipur - 302017

Arkay College of Engineering & Technology - Zaheerabad

College of Engineering - c/o Andhra University,Visakapatnam- 530003

College of Engineering - Anantapur- 515002

Mona College of Engineering and Tech. - Nalgoda , Gollanguda Village , Andhra Prades.

Regional Engineering College - Warangal-506004

Vignan Institute of Technology - Guntur