Bakki Shower/Bacteria House vs Conventional Submerged Filtration System.

[James P]

I know Roger, remember we talked about it once?!

Roger, I've used a lot of media over my 40 plus years of general fish keeping. In fact, to be as modest as I can, I've used them all! In all cases, they work! Because bacteria will grow on anything! Including glass plates! So I've used plastic in all shapes and sizes, horse hair, filter strands, air conditioning matting, wools, sands, stones, lava rock, BH, heated glass beads, pitted glass, resins, carbon, shells, zeolite, ribbon-----

The only differences are :

How the pieces work individually- do they have large or small surface, void space, encourage or discourage bacteria attachment, leech anything into the water , absorb anything from the water? etc.

How they work collectively- do they work well individually but pack too tightly as a group? Do they clog or trap detritus? How do they hold up over time? Do they pack after water has worked through them for a while?

How do they work in different situations- submerged or as TT or wet/dry action media? Are they better stationary or as dynamic application? Do they require special flow or aeration to be efficient? Some applications and associated media create lush biofilm ( organic and inorganic processing) others are purely inorganic reactors and thin, very very efficient, albeit limited in population diversity and resiliency.

Then in total, which is the most appropriate for the need. Which is most efficient, all things considered.

I have no doubt about your results. I think you are rightly measuring your observations against previous observations/ experiences. Depending on your former experiences and media used , I’m sure its possible to be quite impressed. I’m also not sure as to what life’s experience plays in this all. I have not had an ulcer infection in my pond in a decade now. I’m not sure why? I do things based on the experience I have gained. I guess it could be because of the filter media? But I kinda doubt that? JR

[hwong]

JR, no need to aplogise . We are almost embarrassed that these smart folks are making all this money out of you folks. Wonder who is more superstitious. The seller or buyer? Heck, if people have the money to spend on these products and feel good about it, maybe that's is good enuf for them.

I dont give a hoot about BH and or its active properties. I am only interested in the system's effectiveness. I have installed a shower system but not with BH. It helped stabilised my water condition. Now, I want to know if BH will enchance the system. I dont want to spend the kind of money that DTBH has spent just to find out. So I do value what he is doing and I am sure others do too.

Come on fellas, let it rest. it is sounding like an old record and a rash that wont go away. Lets give some respect to DTBH's thread on his experiment and all others who are keen to find out. It is a pain having to bloody sieve thru all this mud to read his and other relevant post.

And Yes , I know I dont own this site. Cheers

[James P]

Hwong, when you're right, you're right! Talking about the 'hows and whys' is the stuff of arm chair keepers!

BH in a trickle tower or a wet/dry application will most certainly work and work well. Pesonally, I would employ BOTH a submerged and an 'above water surface' type filtration if I had the room and the cash ( And I do! ) This way, you have all the benefits of the microbial life that each approach encourages.
I was very disappointed to see Maeda replace his Jmat with BH completely. Really though he was onto something good using the wet/dry bakki at the end of his filter design. I assume he feels the submerged Jmat was acting as a nitrogenous waste/ conductivity ' drag' on the system? I understand that but think loosing the lush biofilm is too much of a trade off. But the BH that replaced the Jmat is still submerged so maybe the results will be the same? I see on my submerged BH, feces and bits of algae is building in the trapped spaces ( held in glass container as filter enclosure so I can see the action at depth).

We now return you to the normally scheduled programming-----

[Valarc]

Tewa - you must not have been paying attention. Not one of the water cluster papers was in a reputable scientific journal. Most were in some way linked to the very people who sell this snake oil. Even JG has given up on that particular road, because it was a thoroughly debunked dead end. Now he's onto the infrared healing thing - which at least has some real papers in real journals. Now if he could only find a paper which ACTUALLY relates to BH in any way, shape, or form, he'd be onto something.

I don't have some secret agenda against momotaro - I've seen some absolutely breathtaking momotaro fish on the forums. I do, however, believe that at the end of the day it's just another breeder, and there is far too much hero worship. ESPECIALLY BY YOU. I also said that it's very possible that the momo folks genuinely believe the FIR crap - but that doesn't make it any more ethical to make it part of their advertising. Their claims are completely unsubstantiated and therefore do NOT belong on any advertising materials. Of course, you sell momotaro wares, so it'd be important for you to talk about how great they are. Which is, of course, why no one should trust your opinion - you clearly have an ulterior motive. And, to distract attention away from your own motives, you continually question mine.

I am a scientist. I am young to the hobby and in no way associated with anyone who could possibly gain anything financially from the discrediting of the FIR claims. I AM, however, also an educator, and I consider it my duty to correct outright ignorance when I see it. Keep looking for secret ulterior motives while you sell the product you are defending - and I hope your potential customers watch and see what an unethical businessman YOU are.

[junglegeorge12]

"Not one of the water cluster papers was in a reputable scientific journal."-val

Another one of your lies, I posted many links to Navy Journals, it is a very hot topic of research with them. But then, I would not expect you to be smart enough to make the connection between the Navy and water. Why might the Navy want to make ceramics capable of affecting water cluster size and bio and chem reactions for ship hulls, underwater detection sensors that must last for centuries, and other things???

Gee, wonder why they did not call emory to ask for help with it. They must have known how smart val was afer all his 'funded work'?lmao

As well, water cluster research from stanford was posted along with research from other funded projects like yours, only difference is they got refunded because they produced worthwhile research, unlike you. I guess you missed the part in the other link about there not being a temp change in the skin or blood in the healing animals and the amount of power being supplied??? You are friggin clueless val. You can't even read. IS this all about your pathetic university wars to be the ones funded? It sure smells like it.

You post lie after lie and try to characterize all federal funded research about this subject as 'science fiction'??? No wonder the DOE fired you. The way they do that is by not givig you contract they think you will renew. They make you an 'offer' you will refuse. It's called politics.

Both you and JR love to negatively characerize others, but the only bad characters here are you two. Neither of you have posted any real science, only tried to debunk the real science. WHY??? And don't give me the puritan bs, you are both way too massive of jerks for that to be the case.

You both know biology is affected by electricity, you both know FIR is a form of energy, you both know there are many materials that emit more FIR than normal. Apparently you both do not know the important role pore size plays in ferroelectric ceramics, that was why I kept asking about it, so you could look dumb. The fact you only talk about pore size as it relates to bacteria growth is funny. Pore size is what affects dielectric properties you ding dong. And electricity, affects biology, even in tiny amounts. That is why the sensors on subs last for decades bean brain. At least do a tiny bit of real research so you don't make complete asses of yourselves.

Here is the really funny part. Missiles are guided by just such ceramics. They produce and send their own signals, as they have no outside source of power. That is not fantasy, or my crazy inventions, but fact. Even funnier, guess where the foremost labs on research in that application are??? JAPAN. Where Bush is right now. I wonder which FIR and ceramic sensors they are using today to detect weapons, sick folks via body temp, and to keep our great president safe. Luckily for them, val has let them in on the secret that none of it is real, it all just a japanese myth. lol

Guess what temp those ceramics are fired at? They are fired at, get this, 1300, just like BH. Gee a pretty friggin amazing coincidence given that that is the same temp superplastic ferroelectric cermics are fired at, and BH has the same materials in it. You do not buy a kiln capable of firing superplastics if you do not already know what you are doing. I guess intel is not your strong suit. A kiln like that costs hundreds of thousand vs a few thousand for a 1200 degree kiln. But being complete dumbasses and all, I would not expect either of you to know that.

That is right, the DOD has worked with their education dep since the war to develop that area as an economic aid for them. Since they are so close to such friendly people as China and N Korea and are not allowed military might, thier very lives depend on being experts in superplastic ferroelectric FIR/IR ceramic sensing, so they can send reliable data to the Navy for help defending themselves. It is not about superstitions, you watch too many movies JR. Defaming them with lies is really unamerican and flat out nasty. You have no morals JR. None. Like EA, your back door buddies, you have no ethics.

The NSF only donated computers to emory, cuz they don't trust the buttbrains there with anything (I guess you could call that 'funding'??). So your insinuations that Japanese labs are unadvance mystics, is total bs. Theya re the worl'ds forerunners byu nescessity in such ceramics and using FIR and IR for security. Sensors immersed in water that do not affect biology and chemistry via FIR/IR and ferroelectricity are worthless.
They know more about ceramics than everyone at po-dunk emory put together.
Take the FIR dielectric ceramics used to sense location and guide missiles, I guess you saw the amazing accuracy of the smart bombs in the Iraq conflict on TV. You can thank ceramics developed by the labs in Japan doing Navy research for that.

Making a version of it for filtration was a VERY smart idea. The Navy already discovered it's many great uses in applictions where water biology and chemistry need to be altered to reduce operating costs and place important long term sensors underwater. If the ceramics does not affect the biology and chemistry priocesses in the water it fouls in months. Ask steve. If you had invested $20 in those journals you would be educated and in a place to commment and perhaps even invent something incredible. I handed it right to you. Geez you and your EA buddies are DUMB. I put it right in your palm to see if you had any sense at all. I always want to know how smart the competition is, or in this case, isn't.


Guess what temp those ceramics are fired at? They are fired at, get this, 1300, just like BH. Gee a pretty friggin amazing coincidence given that that is the same temp superplastic ferroelectric cermics are fired at, and BH has the same materials in it. You do not buy a kiln capable of firing superplastics if you do not what you are doing and are not making a serious high tech cermic product. The production and energy costs for it are huge. I guess intel is not your strong suit. A kiln like that costs hundreds of thousand vs a few thousand for a 1200 degree kiln. But being a complete dumbass and all, I would not expect either of you to know that.

Reducing water cluster size with FIR is one of the best ways to do that. Ask NASA. They are the ones who taught me about that, they have tons of ongoing research on it that is pulling funding AWAY from colloid research, interestingly enough. They are using it to investigate the water vapor in the ozone to watch and provide solutions for global warming. One of the characterisitcs of global warming is reduced water cluster size allowing more of the sun's rays through the ozone, heating us up. Interesting val never mentioned that subject. They are using those ceramics for the same field I worked in, sensing and solutions.

Those are the facts JR, not fantasy, not one of your movies or novels. Real life. Is reality hard for you to handle? Is that why you live in a zoo?


Your stories are funny, to the shallow and the ignorant. They are also fantasy and an attempt to again negatively characterize others. The only science you seem to be good at is the mental art of manipulation via characterization. You have no clas JR, you know you are not applying science, so I can only assume you are flat out intentionally malicous.

BH works, and it works why they say it works. Get over it. It isn't our fault you cannot make a worthwhile filter solution yourself.

[James P]

From the Bunk House page of pseudoscience:



The pseudoscience

Virtually all of the outfits flogging wonky wellness waters purporting to be "clustered", "unclustered", or otherwise altered in structure claim that one benefit of their product is to promote "cellular hydration" by allowing water to more easily pass through cell walls. This is supposed to improve health and performance, and even halt or reverse aging.

Some of the sales sites, for example, say that "the perfect shape of these water molecules allows them to slip easily through the cell membranes, carrying nutrients into the cells and carrying waste and toxins out."

This is all deceptive commercial humbug; there is no credible scientific evidence for any of these claims.

The Science

It turns out that over 3 billion years of evolution has done an exquisitely good job of accommoding cells to plain ordinary H2O— something that no self-styled "inventor", working in his garage, is likely to be able to improve on. Water transport across cell walls is mediated by "water channels" through which plain, ordinary water molecules pass in single file (that is, unclustered) at a rate of around a billion per second. These channels are made of specialized membrane proteins known as aquaporins. A typical channel along with the H2O molecules inside it is depicted schematically on the left, and as a molecular model image at the right.





Peter Agre of Johns Hopkins University was a co-winner of the 2003 Nobel Prize in Chemistry for his 1991 discovery of the aquaporin water channel.

[junglegeorge12]

Here is another 'bunk buster' bomb for your wrong ideas JR. That site you posted was made by a retired, out of date, jerk. WE are not claiming to heal cancer, just enhance filtration in a shower via FIR dielectric ceramics and it's obvious effects on biology and chemical processes in the water at the point where the bacteria strains grow. Simple. So please quit posting links to psuedo science sites and trying to characterize us with them. You are trying an age old techinque of guilt by YOU associating them with us. Enhancement of biological filtration and what you just posted about are not even related. Stop it.


This is an article by the US Navy Research Dep on ceramics. If you read it JR, it should help you understand the basics of ceramics like these. Which you clearly do not. Please not where the predominant amount of funded, cutting edge research on that area of ceramics is being done. It isn't emory or gitville. It is Japan.

Please take the time to read them carefully. You have been very careful to be as destructive to both me and Momotaro as you can be, I hope you will be equally as careful to investigate the actual real R&D science. I will follow this report wiht several others. Please be patient and read them carefully while you wait. Getting permission and then reformatting them so they can be posted here takes time.


Office of Naval Research International Field Office

35. Piezoelectric Single Crystals
Dr. Jun Kameda
October 3, 2003
__________________________________________________ ______________________________
These reports summarize global activities of S&T Associate Directors of the Office of Naval Research
International Field Office (ONRIFO). The complete listing of newsletters and reports are available
under the authors’ by-line on the ONRIFO homepage:
http://www.onrifo.navy.mil
or by email to kamedaj@onrasia.navy.mil

Contents:
Summary
Background
Assessment
Points of Contact

Keywords: Piezoelectric single crystal (SC), Curie temperature (Tc), Electromechanical coupling constant (k33), Dielectric constant (K3T, K3S), Pb(Mg1/3Nb2/3)3-PbTiO3 (PMN-PT), Pb(Zn1/3Nb2/3)3- PbTiO3 (PZN-PT)
Summary

It is recognized that relaxor based single crystals (SCs) like Pb, Zn or Mg niobate-Pb titanate (PZN-PT or PMN-PT) solid solution with near composition of morphotropic phase boundary (MPB), which have excellent electromechanical properties, are potential next generation materials for transducers and actuators. However, flux inclusions and compositional variation persist within wafers cut from conventionally grown relaxor-PT SCs. Such problems hinder the use of relaxor SCs in medical and industrial imaging devices and Navy undersea transducers. Prof. Lim at National University of Singapore (NUS) and Prof. Ye at Simon Fraser University (SFU) are engaged in FY03 NICOP entitled “High-Homogeneity PMN-PT Crystal/Wafers via Improved Flux Growth Technique” with strong endorsement of Drs. W. Smith and C. Wu at the ONR-HQ.
Nondestructive Evaluation of Large-area PZN-8%PT Single Crystal Wafers (Microfine Materials Technology: Business Incubator of NUS)
A multi-electrode nondestructive evaluation (NDE) technique is developed to check the quality assurance of large-sized (> 25 x 25 x 0.5mm) (001)-oriented 0.92Pb(Zn1/3Nb2/3)0.3- 0.08PbTiO3 (PZN-PT) wafers processed by an improved flux method developed at NUS. The NDE technique is used to determine the distribution of Curie temperature (Tc), dielectric constant (K3T, K3S), loss tangent (tand) and thickness coupling coefficient (kt) and electromechanical coupling constant {k33 = (1 - K3S/K3T)0.5} within the large wafer deposited by multi-electrodes, which is directly related to the composition of the relaxor SC. The quality assessment is carried out according to the methodology shown in Fig. 1: (i) visual check of defects and cracks, (ii) Tc measurement using deposit Au array electrodes, (iii) overall measurement of K3T, tand and kt on selected dices using deposit Cu/Au complete electrodes and (iv) distribution measurement of K3S, tand and kt. The typical PZN-PT plate shows Tc of 167oC (±2oC), K3T of 5200 (±10%), K3S of 600 (± 10%), tand of < 0.01, kt of 0.55 (±5%) and k33 = 0.94 (±2%). Similar approach can be applied to PMN-PT system.
Large {(1-x)PMN-xPT} Single Crystal (Microfine Materials Technology: Business Incubator of NUS)
It has been examined how the B2O3 content in PbO fluxes affects the growth behavior of large-sized relaxor-PT {(1-x)Pb(Mg1/3Nb2/3)0.3-xPbTiO3: x = 0.28-0.32} SCs. At low B2O3 contents, abundant flux inclusions form in the initial portion of the grown crystals while the later grown portion is relatively inclusion-free. A cluster growth mechanism is considered to control the growth of crystals associated with considerable composition variations. With increasing sufficiently B2O3 content, the flux inclusions disappear and crystal growth occurs with a microscopic (001) layer growth mechanism. The formation of flux inclusion would be related to the ionic complex in the solution, which is affected by the content of B2O3. By optimizing the B2O3 flux, a large inclusion free PMN-PT SC with the size > 25 mm are successively grown. The composition uniformity of the SC can be achieved by promoting microscopic (001) layer growth of the crystal.

Analysis of Morphotropic Phase Boundary (MPB)
In order to optimize the composition and processing condition of relaxor-PT SCs, it is important to investigate the structure near the MBP that separates the rhombohedral (relaxor side) and tetragonal (ferroelectric side) phase (Fig. 2). Synchrotron X-ray powder diffraction analysis on unpoled samples of (1-x)PMN-xPT with x = 0.3-0.39 indicates that the monoclinic phase, consisting of a multiple coexisting structures with Mc-type as the major component, stabilizes in a range of x from 0.31 to 0.37 at 20 K. Prof. Ye’s group has applied polarized light microscopy to conduct in-situ observation of a complex change in morphotropic domain structure of 0.65PMN-0.35PT SCs, composed of both the rhombohedral and tetragonal phases intimately mixed together. It is suggested that the substitution of Ti4+ ions for the B-site complex (Mg1/3Nb2/3)4+ ions in the PMN-PT causes long range symmetry to break. The piezoelectric constant (d33) and K3T in 0.67PMT-0.33PT become smaller than in the rhombohedral phase near the MPB while d33/K3T and kt remain the same.
2. Background
The development of advanced sonar materials with improved piezoelectric properties to construct three-dimensional images is underway. This requires the fabrication of piezoelectric SCs with complex phases and a large size, which is a significant challenge. Bridgman, flux and their combined methods have been applied to accomplish it. Yet, the transformation from the liquid to solid phase makes it difficult to fabricate SCs with homogeneous chemical composition due to the segregation at the solid/liquid interface.
3. Assessment
A great deal of piezoelectric SCs with high performance of piezoelectric properties has been achieved. However, better and economical processing methods are still required to replace conventional polycrystalline piezoelectric materials. Prof. Lee at Sunmoon University in Korea has successively applied a solid-state crystal growth technique to grow fully dense and chemically homogeneous 0.68PMN-0.32PT SCs. The report is listed in ONRIFO website: http://www.onrifo.navy.mil/reports/2003/HYLee-Piezo.pdf

4. Points of Contact
For further information, please contact:
Dr Jun Kameda
Associate Director, Materials Science
Office of Naval Research International Field Office-Asia
Phone: +81-3-3401-8924
Fax: +81-3-3403-9670
Email: kamedaj@onrasia.navy.mil
Assoc. Prof. Leong-Chew Lim
National University of Singapore
Department of Mechanical Engineering
Phone: +65-9874-2247
Fax: +65-9779-1459
Email: mpelimlc@nus.edu.sg
Assoc. Prof. Zuo-Guang Ye
Simon Fraser University
Department of Chemistry
Phone: +604-291-3351
Fax: +604-291-3765
Email: zye@sfu.ca
The Office of Naval Research International Field Office is dedicated to providing current information on global science and technology developments. Our World Wide Web home page contains information about international activities, conferences, and newsletters. The opinions and assessments in this report are solely those of the authors and do not necessarily reflect official U.S. Government, U.S. Navy or ONRIFO positions.


Fig. 1. Assessment methodology of PZN-PT wafer


Fig. 2. Phase diagram of (1-x)PMN-xPT. C, R and T designate cubic, rhombohedral and tetragonal structure, respectively. The shade area indicates monoclinic phase near the morphotropic phase boundary (MPB).

[James P]

Dear Reader, please note that in this last post I have responded with some facts that actually has SOMETHING to do with cluster water pseudoscience and living cells in — wait for it---- WATER!!!

NO microwave technology, radionics, navy adventures ( closest our outer space guy George has managed to get to ‘water’ in his evidence presentations!) , world politics, patriotism, guided missile systems, Iraq wars or even ‘mail boxes’!

By the way, I tried the experiment with the rat’s ‘shaving cuts’ and the FIR and it was going well until they all drowned. What should I do next Jungle George? LOLs

JR

PS George I counted the insults in your last post - 15! Very impressive! My recommendation? Try a little decaf

[junglegeorge12]

Here is another one that should help to clarify the link between grain size, pore size, and ferroelectric prperties and other thinkgs. The article smore pointed at FIR and ferroelectrics on biology and chemistry in water are not easily obtianed with permission to pos themo nt he internet, which I is why I asked you to buy the journals. If you had done so, we would not even be having this conversation.

These reports summarize global activities of S&T Associate Directors of the Office of Naval Research

International Field Offices (ONRIFO). The complete listing of newsletters and reports are available

under the authors’ by-line on the ONRIFO homepage:

http://onrifo.navy.mil

or by email to kamedaj@onrasia.navy.mil

Contents:

Summary

Background

Assessment

Points of Contact



Keywords: Superplasticity, High strain rate, Composite ceramic system, Yttria stabilized zirconia (YSZ), Alumina, Spinel, Grain growth, Additive effect of oxides

Summary

Superplastic behavior of metallic and ceramic systems can be utilized to improve the shape-forming technology. The constitutive law controlling superplasticity is represented by the relationship of the strain rate (ė) to the grain size (d), the stress component and the diffusion process controlling dislocation motion in the grain interior or along grain boundaries (GBs) and it is given by



ė » (Gb/kT)(b/d)p {(s-so)/G}n Doexp(-Q/RT) (1)



where G the shear modulus, b the Burgers vector,k Boltzmann’s constant, T the absolute temperature, p the grain size exponent, s & sothe applied & threshold stresses, n the stress exponent, Do the pre-exponential factor, Q the activation energy and R the gas constant. In Eq. (1), the variables and term of p, n and Doexp(-Q/RT) are related to the mechanism of diffusion controlling superplastic deformation. In general, promoting the GB sliding and preventing the grain growth and GB cavitation, which can be achieved by refining the grain size, cause the superplasticity to readily occur under a low energy barrier against the dislocation motion.



High strain rate superplasticity

The Kim & Hiraga group at the National Institute of Materials Science in Japan has fabricated a unique composite ceramics with high strain rate superplasticity. The composite system is composed of 3 mol%Y2O3 stabilized tetragonal Zr2O (YSZ), MgO/Al2O3 spinel (both of d: 0.18 mm) and a-Al2O3(d: 0.29 mm), all the components of which have similar volume fractions. The composite ceramics were prepared as follows. The starting materials had powder forms of a-Al2O3 (diameter: 0.2 mm), YSZ (diameter: 0.07 mm), and MgO (diameter: 0.017 mm) with purity > 99.97%. The powders were mixed in a ball-mill using pure Al2O3 balls and the mixed powers were pressed at 40 MPa followed by cold-isostatic pressing at 200 MPa. The compacted powder was finally sintered at 1,400oC for 1 h. The three-phase composite ceramics, exhibit superplastic deformation behavior at 1,650oC with uniform elongation to failure (ef) of 390% and 1,050% and maximum flow stress (sm) of 90 and 43 MPa under ė = 1.0 s-1 and 0.4 s-1, respectively, which are much faster than the conventional range of ė from 10-5 to 10-4 s-1. During the superplastic deformation, the average volume fraction of cavities remains very small ranging from 0.05 to 0.06. The high ė superplasticity is ascribed to a combination of the limited grain growth in the constitutive phases, which would suppress the cavity formation, and the intervention of dislocation activity in the YSZ grain matrix.



Additive effects on the superplasticity

Prof. Sakuma’s group at the University of Tokyo has investigated the effect of doping various oxides like SiO2, TiO2 and GeO2 on the superplasticity of 2.5 mol% YSZ. The addition of 5 mass% SiO2 with glass phase, which suppresses the grain growth, promotes dramatically the superplasticity with ef of 1,165% and sm of 8 MPa at 1500oC under ė = 6.2 x 10-4 s-1. The segregation of Y and Si at GBs and the formation of amorphous glass phases at the triple GB junction are also responsible for amplifying the ductility. On the contrary, the addition of TiO2 and GeO2, which enhances the grain growth and the self-diffusion, does not improve the superplasticity as much as that of SiO2. This is because the effect of grain growth during the elevated temperature deformation overwhelms that of softening.

Background

Prof. Wakai at the Tokyo Institute of Technology (previously affiliated with National Industrial Research Institute in Nagoya) first has demonstrated the superplastic behavior in fine-grained ceramics (d: 0.2-0.3 mm) under ė from 10-5 to 10-4 s-1. His pioneering works include the following:

Sintered 3 mol% YSZ, consisting of 90% tetragonal and 10% cubic grains, was deformed up to ef =120-170% depending on ė at 1450oC with sm of 6-15 MPa: Adv. Ceram. Mater, 1, 259 (1986).

Si3N4/SiC composites showed ef of 150% and sm of 50 MPa at 1600oC. The superplasticity is related to the formation of intergranular liquid phases resulting from the sintering additive of Y2O3 and Al2O3: Nature, 344, 421 (1990).

1 mass% B & 3.5 mass% C-doped SiC, fabricated by hot-isostatic pressing, exhibited superplastic deformation over ef of 140% at 1800oC in the absence of intergranular amorphous phases: J. Am. Ceram. Soc., 82, 2916 (1999).

Since Wakai’s discovery, a number of studies on superplasticity of several ceramic systems were carried out under Towards Innovation in Superplasticity (1996-99) funded by the Ministry of Education in Japan.

Assessment

The utilization of superplastic behavior of ceramics would be vital to further promote the application of advanced ceramics. Although great progress is underway, the superplasticity is still limited at temperatures higher than 1,300oC and at strain rates lower than 10-4 s-1. These conditions are not economically feasible for a practical forming process.

4. Points of Contact

For further information, please contact:

Dr. Jun Kameda

Associate Director, Materials Science

Office of Naval Research International Field Office-Asia

Phone: +81-3-3401-8924

Fax: +81-3-3403-9670

Email: kamedaj@onrasia.navy.mil



Dr. Byung-Nam Kim

National Institute for Materials Science

Phone: +81- 298-2539

Fax: +81-298-2501

Email: kim.byung-nam@nims.go.jp



Prof. Taketo Sakuma

University of Tokyo

Department of Materials Science and Engineering

Phone: +81-3-5841-7153

Fax: +81-3-5841-8653

Email: sakuma@ceramic.mm.t.u-tokyo.ac.jp



Prof. Fumihiro Wakai

Tokyo Institute of Technology

Materials and Structures Laboratory

Phone: +81- 45-924-5361

Fax: +81-45-924-5390

Email: wakai@msl.titech.ac.jp



The Office of Naval Research International Field Office is dedicated to providing current information on global science and technology developments. Our World Wide Web home page contains information about international activities, conferences, and newsletters. The opinions and assessments in this report are solely those of the authors and do not necessarily reflect official U.S. Government, U.S. Navy or ONRIFO positions.

[James P]

O dear--- well when without facts revert to a storm of buster I guess?

And rest assured George, next time I want to grow peas or send nuclear missiles into my biofilter I will refer to this valuable information you have posted here--- gezzzzzzz

But, for now, to defend the honor of the poor chemist who won the 2003 Nobel prize for chemistry with his work with water and living cells----

( sorry to disappoint- no rockets, space ships or mail boxes included in this article! )


The Nobel Prize in Chemistry 2003 – Information for the Public

8 October 2003

All living matter is made up of cells. A single human being has as many as the stars in a galaxy, about one hundred thousand million. The various cells – e.g. muscle cells, kidney cells and nerve cells – act together in an intricate system in each one of us. Through pioneering discoveries concerning the water and ion channels of cells, this year’s Nobel Laureates Peter Agre and Roderick MacKinnon, have contributed to fundamental chemical knowledge on how cells function. They have opened our eyes to a fantastic family of molecular machines: channels, gates and valves all of which are needed for the cell to function.

Molecular channels through the cell wall

To maintain even pressure in the cells it is important that water can pass through the cell wall. This has been known for a long time. The appearance and function of these pores, remained for a long time as one of the classical unsolved problems of biochemistry. It was not until around 1990 that Peter Agre discovered the first water channel. Like so much else in the living cell, it was all about a protein.

Water molecules are not the only entities that pass into and out of the cell. For thousands of millions of cells to be able to function as something other than one large lump, coordination is required. Thus communication between the cells is necessary. The signals sent in and between cells consist of ions or small molecules. These start cascades of chemical reactions that cause our muscles to tense, our eyes to water – indeed, that control all our bodily functions. The signals in our brains also involve such chemical reactions. When we stub a toe this starts a signal moving up towards the brain. Along a chain of nerve cells, through interaction between chemical signals and ion currents, information is conveyed from cell to cell like a baton in a relay race.

It was in 1998 that Roderick MacKinnon succeeded for the first time in showing what ion channels look like at atomic level – an achievement which, together with Agre’s discovery of water channels, opened up entirely new research areas in biochemistry and biology.

The medical consequences of Agre’s and MacKinnon’s discoveries are also important. A number of diseases can be attributed to poor functioning in the water and ion channels of the human body. With the help of fundamental knowledge of what they look like and how they work, there are now new possibilities for developing new and more effective pharmaceuticals.

Water channels
The hunt for the water channels
As early as the middle of the nineteenth century it was understood that there must be openings in the cell membrane to permit a flow of water and salts. In the middle of the 1950s it was discovered that water can be rapidly transported into and out of cells through pores that admit water molecules only. During the next 30 years this was studied in detail and the conclusion was that there must be some type of selective filter that prevents ions from passing through the membrane while water molecules, which are uncharged, flow freely. Thousands of millions of water molecules per second pass through one single channel!

Although this was known, it was not until 1992 that anybody was able to identify what this molecular machinery really looked like; that is, to identify what protein or proteins formed the actual channel. In the mid-1980s Peter Agre studied various membrane proteins from the red blood cells. He also found one of these in the kidney. Having determined both its peptide sequence and the corresponding DNA sequence, he realised that this must be the protein that so many had sought before him: the cellular water channel.

Agre tested his hypothesis in a simple experiment (fig. 2) where he compared cells which contained the protein in question with cells which did not have it. When the cells were placed in a water solution, those that had the protein in their membranes absorbed water by osmosis and swelled up while those that lacked the protein were not affected at all. Agre also ran trials with artificial cells, termed liposomes, which are a type of soap bubble surrounded on the outside and the inside by water. He found that the liposomes became permeable to water if the protein was planted in their membranes.



What is osmosis?
The liquid pressure in plant and animal cells is maintained through osmosis. In osmosis, small molecules (such as water) pass through a semi-permeable membrane. If the membrane does not admit macromolecules or salts that are in higher concentrations on one side of the membrane, the small molecules (water) will cross to this side, attempting to "dilute" the substance that cannot pass through the membrane. The osmotic pressure thus arising is the reason why cells are often swollen and stiff, in a flower stalk, for example.

Peter Agre also knew that mercury ions prevent cells from taking up and releasing water, and he showed that water transport through his new protein was prevented in the same way by mercury. This made him even more sure of that he had discovered what was actually the water channel . Agre named the protein aquaporin, "water pore".


How does the water channel work? A question of form and function
In 2000, together with other research teams, Agre reported the first high-resolution images of the three-dimensional structure of the aquaporin. With these data, it was possible to map in detail how a water channel functions. How is it that it only admits water molecules and not other molecules or ions? The membrane is, for instance, not allowed to leak protons. This is crucial because the difference in proton concentration between the inside and the outside of the cell is the basis of the cellular energy-storage system.

Selectivity is a central property of the channel. Water molecules worm their way through the narrow channel by orienting themselves in the local electrical field formed by the atoms of the channel wall. Protons (or rather oxonium ions, H3O+) are stopped on the way and rejected because of their positive charges



The medical significance of the water channels
During the past ten years, water channels have developed into a highly topical research field. The aquaporins have proved to be a large protein family. They exist in bacteria, plants and animals. In the human body alone, at least eleven different variants have been found.

The function of these proteins has now been mapped in bacteria and in plants and animals, with focus on their physiological role. In humans, the water channels play an important role in, among other organs, the kidneys.

The kidney is an ingenious apparatus for removing substances the body wishes to dispose of. In its windings (termed glomeruli), which function as a sieve, water, ions and other small molecules leave the blood as ‘primary’ urine. Over 24 hours, about 170 litres of primary urine is produced. Most of this is reabsorbed with a series of cunning mechanisms so that finally about one litre of urine a day leaves the body.

From the glomeruli, primary urine is passed on through a winding tube where about 70% of the water is reabsorbed to the blood by the aquaporin AQP1. At the end of the tube, another 10% of water is reabsorbed with a similar aquaporin, AQP2. Apart from this, sodium, potassium and chloride ions are also reabsorbed into the blood. Antidiuretic hormone (vasopressin) stimulates the transport of AQP2 to cell membranes in the tube walls and hence increases the water resorption from the urine. People with a deficiency of this hormone might be affected by the disease diabetes insipidus with a daily urine output of 10-15 litres.

Ion channels

The cells signal with salt!
The first physical chemist, the German Wilhelm Ostwald (Nobel Prize in Chemistry 1909) proposed in 1890 that the electrical signals measured in living tissue could be caused by ions moving in and out through cell membranes. This electro-chemical idea rapidly achieved acceptance. The notion of the existence of some type of narrow ion channel arose in the 1920s. The two British scientists Alan Hodgkin and Andrew Huxley made a major breakthrough at the beginning of the 1950s and for this were awarded the Nobel Prize in Physiology or Medicine in 1963. They showed how ion transport through nerve cell membranes produces a signal that is conveyed from nerve cell to nerve cell like a relay race baton. It is primarily sodium and potassium ions, Na+ and K+, that are active in these reactions.

Thus as much as fifty years ago there was well-developed knowledge of the central functions of the ion