Cell Definition and 899 Threads

  1. Physics345

    Cell Phone EM Waves - Health Risks & Physics Explained

    Homework Statement A cell phone sends and receives electromagnetic waves in the microwave frequency range. a) Explain the physics of how an oscillator creates these waves. b) Research the possible side effects of using cell phones. citing at least three websites that you consider reliable...
  2. L

    Potentiostat and powersource in electrochemical cell

    Hi, Could someone please explain to me some terminology. Is a potentiostat considered a "power source" for an electrochemical cell (the cell is for the CO2 reduction reaction). An example of this type of cell can be seen here...
  3. G

    Cell Phone Tower Communication: How Does it Work?

    Pardon my ignorance if this is simply stated in wikipedia although I thought to ask here, So I am wondering how does exactly a radio tower communicate with a cell phone? Yes obviously by radio waves in the microwave? or so about region, but ok let me try to ask this in stages, 1)The radio...
  4. srinaath

    Why do we need to supply air to the cathode of a hydrogen fuel cell

    I am trying to understand the working of simple hydrogen fuel cell. We have anode (negative terminal), cathode (positive terminal), catalyst at anode to separate negative and positive ions of hydrogen atoms and electrolyte which allows only positive ions. We will be sending hydrogen fuel at...
  5. I

    Term for differentiation within the cell

    I understand that the terms "differentiation" and "epigenetic" apply to cells in multicellular environment, and that different DNA is expressed to create distinct features in different cells. What about the process of the creation of distinct features within the cell itself, such as all the...
  6. J

    Microbiological Fuel Cell: Negative Voltage

    Hello! I've been working on a few soil based MFCs and I have been monitoring my voltage and energy output for a week now. I've made the electrodes by covering stainless steel metal meshes with activated carbon using epoxy. I've gotten some funky results as attached. As you can see... the...
  7. W

    Max power of a photovoltaic cell -- where did I go wrong?

    1. The problem statement, all variables and given/known da Show that for a PV cell finding a maximum of power leads to the following equation: ##(1 +\frac{qV_{max}}{kT})\exp\left(\frac{qV_{max}}{kT}\right) = 1 + \frac{I_{sc}}{I_{rs}}## ##I_{sc}## is short circuit current and ##I_{rs}## is...
  8. I

    What happens to a cell if a chromosome gets damaged

    Hi, I was wondering what would happen to a cell if one of the chromosomes gets destroyed or damaged in a section? I am guessing that, if the "housekeeping genes" and expressed genes are intact, the cell, would be ok or somewhat ok? If it can survive, would it affect its ability to do mitosis...
  9. C

    Finding Potential Difference Across AB in a Multi-Cell Circuit

    Homework Statement Find potential difference across AB Homework EquationsThe Attempt at a Solution I have posted a picture of my figure, I have 3-i1=v=2-i2=1-i3 and i1+i2+i3= io on solving I got 6-io=3v and then I found resistance equal to 1/3 ohm. So after solving I got v= 1 volt, but it's wrong
  10. C

    Potential difference in multi cell circuit

    Homework Statement Find potential difference between a and b in the figure Homework Equations Q=cv The Attempt at a Solution can anybody tell me how to apply the equation in this problem with more than one cell [/B]
  11. W

    Excel: Inserting many Horizontal rows in same Cell

    Hi all, I have been trying unsuccessfully to figure out how to insert many horizontal rows into the same cell in Excel: I have gone over many sites, asked people, all sorts of key combinations, without success. Any ideas you know work, please? Thanks.
  12. O

    Unit cell conversion and shape of fuel pellet

    As you may know, below is the conversion process of square unit cell into circular shape in order to calculate the thermal utilization factor (f) for a lattice. As far as I know, it is really difficult to make a simulation for which a lattice is constructed as a circular fuel and square...
  13. Cool4Kat

    How much current does a cell phone use?

    I am doing a series of videos on the history of electricity and I am working on a video on Volta and the first battery. Anyway, I want to compare the voltaic pile to a typical li-ion battery running my iPhone. Now the voltaic pile could easily create 20 V of potential but it had high...
  14. D

    Solar Cell Problem(semiconductor)

    Homework Statement Homework Equations Voc=kt/q x ln(tpXGlXNd/(ni)2) Isc=A x q x Lp x Gl Lp=√(Dp×tp) FF=Pma/(Isc*Voc) The Attempt at a Solution I got Voc=.298 V and Isc=3.04 mA I]However, I am confused as to how to find the fill factor. I know it is the maximum voltage and current the load...
  15. D

    Are Human Cell Walls Capacitors?

    Homework Statement Some cell walls in the human body have a layer of negative charge on the inside surface. Suppose that the surface charge densities are ##±0.50 \times 10^{-3} C/m^2## , the cell wall is ##5.0 \times 10^{-9} m## thick, and the cell wall material has a dielectric constant of...
  16. A

    A Origin of the polarization in BaTiO3 unit cell

    hi, in perovskite crystal, such as BaTiO3, due to the off-centre of Ti ion, there exists a polarization moment in the unit cell (as shown in below link). my question is: does the disposition of Ti atom lead to separation of electron cloud from the nuclei of the Ti atom and so the Ti atom plays...
  17. hilbert2

    IR transmission through a very thin liquid-filled cell

    Hi, does anyone know if it's possible, with a Nicolet is50 FTIR spectrometer or similar, to measure the transmittance of IR radiation through a cell filled with a liquid sample with thickness in the range of about 10 microns and accurately adjustable? The reason for doing this would be because...
  18. L

    What's Wrong with the First Primitive Cell Choice?

    Homework Statement When calculating the Fourier coefficients of the potential of the following lattice (the potential is a sum of deltas at the atom sites): I get the wrong coefficients if I choose the following primitve cell, with primitve vectors a1,a2: And the right coefficients if I...
  19. Zeynel

    What Are Telomeres and How Do They Relate to Aging?

    I read that cells in human body are continuously oxidized. Can you explain in layman's term what this means? Is it possible to explain cell oxidation withot reference to "electron loss." Because I cannot imagine visually how a cell can lose an electron or what that means.
  20. B

    What is the Capacity Factor of Glycolysis in Cells?

    Hello. I'm in the process of teaching myself cell bio and I'm curious to find a good source with actual rates of glycolysis in cells. In a nutshell, I'm wondering what the maximum rate of ATP production within the cell is (assuming a normal yet constant extracellular concentration of glucose)...
  21. C

    Internal resistance of a battery cell

    if a cell is running down, there would be a constant drop in p.d. across the cell, does the internal resistance of the cell increase or decrease?
  22. D

    Getting rid of fuel cell / flow battery membrane

    I am aware of laminar flow but would like to look for some other ways. Is it possible to block ions from flowing in the "wrong" direction by applying a magnetic field to the electrolyte and let neutral molecules pass through?
  23. A

    How shunt and series resistance in a PV cell changes? Or are they stable?

    i really need help about shunt and series resistances i just want to know if they are constant or variable ? if they are variable what make them increase or decrease?
  24. A

    I What is the main role of doping in a solar cell?

    Is doping only to form an electric field in depletion region? Somehow I'm confused as far as I'm reading right now, the doping-generated carrier never discussed its role in the solar cell (other than leaving the ion and causing an electric field). Is not the number of carriers generated by...
  25. S

    Voltage output of a photodiode (solar cell)

    Hi, I'm trying to figure out how the angle of incidence will affect the voltage output of a photodiode. The obvious answer that comes to my mind is that the voltage output should be proportional to the cos(α), where α is the angle of incidence of light. However, I couldn't find any...
  26. W

    Thermodynamic cycle of a solar cell

    Mechanical Engineering Undergrad here: So this didn't seem explicitly like a homework question, but I was wondering how to describe a solar cell in terms of thermodynamics. If I had to model it with the first law of thermodynamics, I would consider it a simple loop of heat/work exchange...
  27. Natalie456

    Salt Bridges in Cells: Voltage & Distance

    I know that salt bridges maintain charge, thus allowing the reaction to proceed. I was wondering if the distance of the electrodes from the salt bridge affects the voltage of the cell in any way. Thanks!
  28. V

    Is first Brillouin zone the same as Wigner-Seitz cell?

    Homework Statement Not a homework question, but I am attempting to understand what exactly the first Brillouin zone is. Homework EquationsThe Attempt at a Solution From my textbook, what I'm gathering is that one constructs the first Brillouin zone by constructing a "Wigner-Seitz" type cell in...
  29. B

    Are load cell signal conditioners limited to sample speeds?

    Hi, I need to buy a bridge amplifier for my load cell. I need to be able to take at least 350SPS (samples per second). The only load cell amplifier I can find within my budget states that it has a selectable 10 SPS and 80 SPS output data rate. Heres the link to the amplifier...
  30. C

    Internal resistance of a cell varying with power drawn

    If we continue to draw a specific amount of power from a cell (re-chargable), how will the internal resistance of the cell vary? Is there any particular mathematical relation between them? Please help me understand
  31. P

    MCNP Error: JCO, Cell Cards & Surface Cards

    hi everyone, i have a mcnp error, it don't finish, it only run a half! i hope someone can help me! thank you! and my code JCO c cell cards 1 1 -0.00117 -100 300 2 2 -1.52 (-100:-101) -300 #1 $solution 3 4 -7.93 (-110:-111)#1#2 $clad 4 3 -1 (-200:-201)#3#1#2 $water 5 4 -7.93...
  32. I

    Average neurotransmitter count in a cell?

    Is there a general average number of neurotransmitters a given cell would "work with"?
  33. Ygggdrasil

    Medical Gene Therapy Successfully Treats Teenage Boy with Sickle Cell Anemia

    *in one patient, for at least 15 months Research published this week in the New England Journal of Medicine reports on a case of using gene therapy to potentially cure a teenage boy of sickle cell anemia, a genetic disease that impairs red blood cell function...
  34. I

    Do cells in the body stay in one place once they have found their position?

    Once cells in the body "find their place" between other neighboring cells, do they stay there touching each other in the same way or do they move around, migrating, sliding around with their membranes? Can a cell just "take off"? I wonder the same about neuron cells and their axons and...
  35. hikari1987

    Joule heating in internal resistances of a solar cell

    Hi , How can I calculate the resistive heating occurring in the internal resistances of a solar cell ? Are ohm's law or the power dissipation relation P=RI2 applicable in this case ? if not the case how can we calculate the resistive heating there? Thank you in advance for your help
  36. S

    How to find the cell voltage of this circuit?

    Homework Statement Find the cell voltage, the current at the 15 OHM resistor is 2A. Homework Equations How would I solve to find the cell voltage? The Attempt at a Solution I tried to find the voltage of the top part of the circuit but I just cannot remember how you would do that or if it...
  37. Biker

    Negative ions affecting galvanic cell voltage

    I saw this more related to physics than chemistry. So I have been trying to model how the voltage is generated in galvanic. I couldn't find any online and I thought it would be a good exercise. I modeled ions as electric charges with different magnitude of charge. Each producing a different...
  38. P

    Solar Cell Current increases as Resistance increases Problem

    Hi everyone, so I'm trying to achieve IV curves based on how this website had done below: http://www.voltaicsystems.com/blog/solar-charger-tutorial-part-2/ But whenever I increase the resistance, the amperage increases rather than decreases! For example, when I use a 500 ohm resistor the...
  39. C

    Solve Galvanic Cell Problem: Iron Oxidation

    http://imgur.com/a/wGTEQ The example is straight from my textbook. Since the iron is being oxidized, and it has a negative cell potential to begin with, wouldn't you flip the equation to make it the anode and in the end add it to the other cell potential?
  40. I

    Do amino-acids spontaneously bond within a cell?

    I was wondering whether it is possible for amino acids that end up in a cell (ready to be made into proteins) to spontaneously start to bond in the cytoplasm (or wherever the routing channel is I guess) and create randomly floating short strands of polymers? Furthermore, can it ever happen that...
  41. B

    A Tools to transform primitive cell orientation

    In case the orientation of a primitive cell is not what I want, is there tools to do a user-supplied 3D rotation to bring the primitive cell to the preferential orientation and output the new coordinates? Thanks,
  42. Thermo

    Fuel cell voltage end efficiency

    I know theoretically fuel cell efficiency decreases as temperature increases. But in practice it is vice versa. What is the reason of that? I couldn't find enough sources. Any kind of help is much appreciated.
  43. B

    A Primitive cell parameter given chemical unit cell info

    Experimentalists usually provide chemical unit cell information including full symmetry (space group) information of the crystal together with coordinates of independent atoms. But this cannot be directly used by ab initio packages, which requires either primitive cell or unit cell information...
  44. S

    Simulink model of a hybrid vehicle (replace battery with fuel cell)

    greetings, here I found a Simulink model on mathswork, I want to replace the battery with a fuel cell, so I'm stuck at the level of the energy management block. here is the link of the model: https://www.mathworks.com/matlabcentral/fileexchange/28441-hybrid-electric-vehicle-model-in-simulink...
  45. A

    How to copy the value of a cell in Excel to a new location?

    Suppose I apply a particular function and I get a value of the cell-A1. How can I copy this value to another cell-C1 and the entire column under C1 to use it in a new operation provided that C1 and the entire column are always updated when A1 changes?
  46. reddvoid

    Synopsys ICC: cell stats and post route netlist from mwlib

    Hi, I have loaded the milkyway database of the design to the synopsys ic compiler how can i get details of all the cells present in the design or the netlist after place and route ? Thanks :)
  47. J

    I Is it possible to calculate Tsupercon from the unit cell?

    Hi folks, It is an elementary question for people expert in superconductivity. I know there is a theory, the BCS theory, and the GIzburg Landau theory too that apparently explains superconductivity. My question is, if I give you a unit cell would you be able to tell me the temperature at...
  48. I

    Are there genes that are expressed in every cell in organism

    I know that different cells in a body express different genes and thus have different functionalities. I am wondering if there are genes that are expressed in all the cells of a certain organism. (or for that matter in all the cells that have that specific gene, for example all mammals.)? For...
  49. LtIvan

    My Static RAM Cell I Made over the Weekend

    Allo, Recently, I have been researching RAM, including formats such as DRAM and SRAM. While I was running simulations on SRAM one week, I realized I could make a 1 bit Static Memory Cell using a simple Schmidt NAND IC. I ran a draft for it displaying two feed backing NAND gates as inverters...
  50. S

    Finding series and shunt resistance of solar cell

    Hi, I am trying to find out series and shunt resistance of solar cell from I-V curve which starts from Isc and going to Voc. I read some papers and for single illumination mostly said Rs= -(dv/dI)V=Voc and Rsh= -(dv/dI)I=Isc. so I am finidng Rs from slope between points from Vmax to Voc, and...
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