Cells Definition and 429 Threads

I don't know if this is the right forum but I'm curious. Companies are searching for alternatives like copper and zinc to make photovoltaic solar cells out of. Could aluminum ever work and be feasible, and replace current rare Earth components?

In a galvanic cell, electrons are supplied by oxidation at the anode. I am struggling to find clarity on what makes the electrons move from the anode to the cathode when a wire is connected between the two. I have come across some texts on the internet that say the electrons are attracted to the...

How does one interpret band structures (i.e. E,k solution pairs for a given Hamiltonian) for a non-primitive cell? I was looking at these slides: http://www.tcm.phy.cam.ac.uk/castep/CASTEP_talks_06/clark2.pdf Slide 9 has the "normal" silicon band structure obtained with a primitive cell...

Hi all, I would appreciate a little guidance on some circuit theory. I was wondering how a circuit behaves when there are, say two identical 10V cells, and a 1Ω bulb happily sitting in series, but then one connects another identical bulb between the two cells. Obviously the current in the first...

My (chemistry) textbook states that maximum work is never achieved in a galvanic (electrochemical) cell due to frictional heating. I've been wondering, could a cell be made with superconducting wires, cathodes, and anodes in order to achieve maximum work? Would this violate the law of entropy?

First, I am not an electrical engineer and am not to familiar with circuit boards. PROJECT: I have a static load, represented by a block. The block has three very short legs (or feet 3/8" diameter each). The feet are located concentricly under the block. Under the feet I place three thin-film...

"The size cells can grow to is limited. Of the cells shown, which one" Practice test question: 12) The size cells can grow to is limited. Of the cells shown below, which one is likely to experience the greatest difficulty as it grows larger assuming it retains the same shape? This is...

I am confused on how osmolarity of cells with water would cause a cell to swell, shrink, or burst. I know that a cell has a solution concentration of 300 mosm. In a lab that was done, we analyzed the impact of a red blood cell in solutions containing different osmolarities. For example, when a...

Test question: "Respiring cells release CO2 into the bloodstream..." 1. 2. For this question, I was thinking about the nature of CO2. It's not an acid or base, so how could it drop or raise the pH level?! So I put that the pH level won't change (B), but the real answer is C (it will...

Here is the full article, just published today: http://phys.org/news/2013-01-quadruple-helix-dna-human-cells.html The article makes it apparent that this discovery could be used to inhibit the reproduction of cancer cells. Does anyone know of any other uses that this discovery could lead to?

i'm very interested in learning about photovoltaic cells, I've read in some sites already but they all describe it in very general way, can anyone tell me on detail how does it work? thanks

How does the efficiency of a Thin Film solar cell compare to the efficiency of a single crystal solar cell with reference to the 5 main solar cell parameters ( Iopt , Rs, Rsh, Is and n )? I know series resistance( Rs ) will probably increase in thin film cells because of grain boundaries...

Hi, I am conducting an experiment whereby I have to measure the individual performance (on a per-cell basis) of solar cells on a solar panel. The panel has 20 cells, which are 4 strings in parallel of 5 cells in series each. The entire panel has a +V and chassis GND wire that I can open or...

What problem arises or may potentially arise if drug molecules bind to plasma cells?

Thought I'd share this article w/ everyone since I found it very interesting. Imagine being able to regulate stem cells without the need for genetic manipulation or growth factors etc. Small molecules are so much easier to work with. Very interesting...

In leukaemia since immature white blood cells increase, do they overcrowd and decrease mature white blood cells. So does neutropenia and thrombocytopenia, leucocytopenia occur in leukaemia. Or does this deped on subtypes eg in some leukaemia B lymphocytes increase. Thanks :smile:

Homework Statement Within cells, small organelles containing newly synthesized proteins are transported along microtubules by tiny molecular motors called kinesins. What force does a kinesin molecule need to deliver in order to accelerate an organelle having mass 0.028 pg from rest to 2.8...

I need to calculate how much power will be generated by a solar cell at AM1.5. The cell is 1.5x3.5cm^2. I know that it is to do with the area of the cell i just don't understand how to work out the power generated without knowing things like the material. Any help would be appreciated.

If I'm "losing muscle mass", are some of my muscle cells actually disappearing? I've been running a lot lately and losing weight. Mostly getting leaner, but recently I've started to worry about losing muscle mass. I used to lift weights a lot, but I haven't done that in a few months. If I keep...

I recently started studying biology because suddenly I started getting curious about this subject. I read about the cell theory which states that all living things have cells. Is this necessary - that all living things have cells? Can't they have some different structure? Also these type of...

Congratulations, you've created a fuel cell car! Now you need electricity or fossil fuels to create hydrogen to fuel the car. So burn some coal to get electricity. How exactly does this help the environment again? What am I missing here?

Hello, PhysicsForums! I've been discussing what little I know of plate tectonics with someone and the other party has suggested that convection cells within the mantle (assuming convection really occurs at all) should eventually move such that they no longer push more matter up through...

Why does the genetic composition of sex cells of an individual vary since the genome of an individual is same throughout his/her body.

I'm doing a presentation on Hydrogen Fuel Cells for my class, but I'm having a hard time understanding how exactly it is that they work. I'm only able to find information on fuel cells and they tend to not be descriptive on the hydrogen part. If someone could please link some articles that...

So, I've read in books and on Wikipedia (see for instance http://en.wikipedia.org/wiki/Carnot%27s_theorem_%28thermodynamics%29#Applicability_to_fuel_cells_and_batteries) that the Carnot efficiency cannot be applied to a fuel cell because it is not a heat engine that produces work, operating...

hi I've got to do a project for college and need some direction I want to know a few things more so if you can help let me know. some of the things include (if you could answer any it would be useful): why can't we make a longer electric current to harness all the electricity produced in a...

Homework Statement Calculate the cell potential at 25°C for the cell: Fe (s) | (Fe^2+ (0.100 M) || Pd^2+ (1.0*10^-5 M) | Pd (s) given that the standard potential for Fe^2+/Fe is -0.45 V and for Pd^2+/Pd is +0.95 V. A. +1.28 V B. +1.16 V C. +1.52 V D. +1.68 V Homework Equations E Cell...

http://www.gatech.edu/newsroom/release.html?nid=128531 Browsing the alumni stuff, I see things that make me wish I were back in school. You kids and faculty are so lucky to be able to do this kind of stuff every day. I have serious envy! Alas, wife, kids, house, bills, argh. Nothing but work...

I am an undergraduate physics student working in a biophysics laboratory, and recently on the job I have started culturing cells. We need the cells in suspension for reasons I can't disclose but the important part is that I am having some difficulties in the trypsinization process. The main...

So a human is made of cells. It is essentially a city or society of cells that live together. There is no such thing as human, it's just a bunch of cells. So human is just a natural phenomenon, an emergent property. In addition, a cell is just a bunch of atoms. I.e. a collection of atoms...

Hey, I needed a clarification regarding this. Are photovoltaic cells ohmic devices? Or if I consider an entire PV Module, will that be an ohmic device or not? I basically need to know whether I can utilize the equation P = I2*R = V*I for a cell or not.

Conditional probability & "r balls randomly distributed in n cells" Homework Statement I'm posting this in hope that someone can give me a correct interpretation of the following problem (problem V.8 of Feller's Introduction to probability theory and its applications VOL I): 8. Seven balls...

So the question is even though we may have some fair idea how multicellularity came about. How would this lead onto specialized line-aged cells in a multicellular organism ? For example differentiating to blood cells or bone cells. http://en.wikipedia.org/wiki/Multicellular_organism

There are reports that stem cells have been successfully used to cure cancer in the lungs, spleen, brain and spine. It was done on a 38 year old man from Las Vegas, but can it cure colorectal cancer? And when was the stem cell cancer therapy first successfully tested?

So we use stem cells from infants for research, but do they never take those stem cells and use it to treat people, is it not possible to make cells from other people live in your body? would your body reject and kill those cells?

Please teach me this: I hear that we can make stem cells from fat tissue that is used in medical treatment.Is that correct? Thank you very much for your kind helping.

Are complex cells in the brain physically different from simple cells or is the difference in their function/role?

I did an experiment testing the thickness of a salt bridge (made of filter paper soaked in potassium nitrate) on the voltage produced from Zn and Cu half cells. This is similar to a thread someone made back in 2007. But I have no idea how to explain my findings or whether the thickness...

Homework Statement Based on the following chart, what ions would you use to construct an electrochemical cell with potential closest to 2.00 V? [PLAIN]http://img546.imageshack.us/img546/5568/electrochemicalcellchar.png Homework Equations I know that I am supposed to add the voltages of...

Hey all I'd like to help me.. thnx in advance here z tha Q's : 1) Two plane parallel conducting plates each have area S and are separated by a distance b. One carries a charge +Q ; the other carries a charge -Q. Neglect edge effects a) What is the charge per unit area on each plate ? where...

In a voltaic cell, why do electrons flow at all? If I place a piece of zinc metal into a zinc ion solution, nothing happens, right? Likewise if I place a copper electrode into a copper ion solution, nothing happens. When I attach the half cells with something that allows electrons to flow...

http://www.bbc.co.uk/news/health-15272081" and and from the research paper linked in the article: Rhody...

I am by no means well versed in nuclear power, but from my limited exposure I have gathered that a very large portion of nuclear energy (and antimatter) is expressed in high energy gamma radiation. All forms of electromagnetic radiation are expressed as photons, correct? Taking the concept of...

I know, as a matter of fact, that the equivalent resistance of three identical cells in parallel is equal to the internal resistance devided by 3. When we are concerning simply 3 equal resistors in parallel, I know that the outcome resistance is what. But when it comes to three cells with...

Hi, I would like to ask you, if you consider NaClO2 harmless for the human body/cells. I am asking because my father want to try the "healing" method described by Jim Humble but I am afraid he can make something bad to his body. I am not good in chemistry, so, I would like to ask you...

why platinum is used in some half cells and not in others?

Any suggestions on vendors for good, well-designed reflecting telescope mirror holding cells, in the ~ 8" diameter range? I've had enough grief from the very poorly-designed cell that holds the primary in my 7" Mak-Newtonian, and am looking to toss it and replace it with something better. Tube...

That is what is on my mind after reading this article: http://healthland.time.com/2011/08/11/mit-scientists-develop-a-drug-to-fight-any-viral-infection/

And does it similarly affect the cells of organisms of any other biological Kingdoms?

HIV completes the life cycle and finally causes the breaks down the T helper cells. During this process, are the T helper cells capable of producing interferon? Just curious. Tried to do some research, but couldn't understand what I read. So, kindly explain in a simplified language.