Cells Definition and 450 Threads

Hello, As you can tell I'm new here. I'm not into science generally but I have come across some discussions online that have gained my interest. So I would like to get a basic understanding of a few things that I don't understand. So my question is, do cells generate heat? And I what I mean is...

I'd like to learn how to test for these types of cells (living or dead) in water. what do I need to do this from home ? is it cheap or expensive to buy the equipment ? please provide details of the equipment needed and just a rough idea as to the cost of doing so at home. oh yeah once i buy the...

Hello, In a battery or a galvanic cell, the electric potential of the battery is due to a difference of charges between the two cells like in a capacitor? if yes, why we call it electromotive force of a battery (EMF) ? Thank you.

I think in Multiple fusion daughter cells are different from parent cell.I interpreted this by looking at the image below Have I interpreted correctly?Is this image reliable?

If a foreign human cell is introduced into one's body by way of blood transfusion or through some other method could these foreign cells survive and take up host in their new environment ? So if a foreign nerve cell is introduced could this nerve cell take up host as a native cell where it can...

Hello. I have no experience as a cellular biologist nor have any lab experience or knowledge. However I would like to know how would one go about finding out what is needed in order to test the following foods mostly for human cells (any kind) : 1. How can I examine the following food items...

Please help me for finding out the voltage equations for series connection of sub cell of triple junction solar cell?how can i connect these cells in series..i want to connect these cells in series in MATLAB/SIMULINK environment... Please help me

Homework Statement Hi all, I have a question about using peltier cells for both cooling and reading temperature in the same moment. I need to cool down a couple of Integrated Circuits so I'll put put a 20mmx20mm peltier cell over them but I cannot read the cold side of the cell because it's...

Homework Statement Four balls are distributed randomly and independently into 4 cells. What is probability that: a) In every cell there is exactly one ball? b) All four balls be in one cell? c)Two balls in one cell ( any) , other two balls in other cell (any)? (assume that the balls are...

How many ways to arrange cells of k possible values in a mxn matrix provided that sums of all rows and columns are known? For example, if we have a 5x3 matrix and 10 possible values ( from 0 to 9) that can be assigned for each cell, then how many ways to arrange cells in that matrix satisfying...

I'm looking to find out what is degenerating in a semiconductor that is being bombarded with beta particles. I know in the low energy tritium beta cells. There is less degeneration because less energy. I know that current is formed by the beta particle making pair holes in the mobile band. Is...

good evening to all if two ideal cells with emf 6 volt and 3 volt are connected in parellel to supply current how the net emf can be decided

Power Source at 6.0V a) Voltage drop across the parallel branch of the circuit: 0.25V b) Voltage drop across the light bulb connected in parallel: 0.25V c) Voltage drop across the light bulb connected in series: 0.5V 2) How would you measure the current through the entire circuit: By putting...

Homework Statement Hi! I have a problem with the following problem: Calculate the efficiency of the solar cells with the characteristics given in the table below Power (28 degrees, BOL): 300 W/m2 Absorptance: <91 , emittance: >82. Reliability: 0.999 . Mass: 2 kg Homework Equations I know...

I went to class and watched this video () but I still don't understand how salt bridges work. I think I memorized all of the details and steps but I don't understand why anything is happening at all! I know that Cu2+ gains two electrons when it touches the electrode but why? And also does the...

I was wondering in Schottky junction solar cells, how is the open circuit voltage dependant on the built in potential and the Schottky Barrier Height?

Im trying to colour excel cells using (r,g,b) values. I understand its possible to do this through macros or through custom functions. Any suggestions / solutions?

Dear All, 1) I am not able to understand the statement given by one of the professor. i,e., Number of primitive cells in a material = Number of K-States. 2) Additionally, if one atom is per primitive cell then why do we have NUMBER of k-states equivalent to number of atoms in this case ? 3)...

I'm reading about short circuit current in a solar PV cell and I am a little confused. The short circuit current is defined as the current across the solar cell when there is zero potential difference across the cell. At this point the short circuit current is equal to the light current. What...

Lately I've started learning about fuel cells, particularly proton exchange membrane fuel cells (PEMFC), and a fairly basic question that has been bugging me is: Since the cathode is positive, it is clear why the electrons flow through the load and to the cathode, but why do the...

Homework Statement The full problem statement (I just need help for part c): You are determining which model of power cell to purchase for your project. Your project requires 6 power cells, at least 4 of which must work for the project to work. You would like your project to work for at least...

Hi, I understand that an exciton must reach the D/A interface within the Exciton diffusion length to prevent recombination, however, what are the factors during device fabrication that can affect the Exciton diffusion length of a P3HT:PCBM BHJ OSC?

What fraction of adult human cells are not replaced over a normal lifetime ?. see ... http://en.wikipedia.org/wiki/Ship_of_Theseus / [ aka "Trigger's broom" ]. I'm guessing it's a minority : brain and heart only account for about 3% of body weight.[ skeleton is replaced every decade , but...

Though I understand the basic combinations of resistors, emf and capacitors, both in parallel and series, complex circuitry questions always baffles me. I would like to know what are the key points? I mean important points to be kept in mind. What are the common mistakes? What are certain tricks...

Are all somatic cells same?As they all are product of mitosis of zygote ,all somatic cells should be identical.If yes then what makes eye cell different from say heart cell i think it is switching on and off mechanism i.e these two cells are exactly the same.They will contain same 46...

This may be debatable and/or depend on recent research. I want your opinion and evidence for that.

I've heard they were much more efficient then li-ion batteries and anything else really.. and drones today are all about flight time, wouldn't hydrogen fuel cells result in a great flight time advantage? why are they not in use?

Homework Statement A voltaic cell utilises the following reaction: 4 Fe2+(aq) + O2(g) + 4 H+(aq) ---> 4 Fe3+(aq) + 2 H2O(l) What is the emf of this cell when [Fe2+] = 1.3 M, [Fe3+] = 0.010 M, PO2 = 0.51 bar and the pH of the solution in the cathode is 3.5. The standard reduction potentials...

Is it because the bloodcells are dried out or because they are attacked by viruses?

Homework Statement i) A human erythrocyte (red blood cell) may be approximated as a disc around 2 microns in height and with a diameter of 10 microns. If the pressure inside were to become large enough for the cell membrane to rupture, where would you expect it to fail, assuming the membrane...

Dumb question. I don't know anything about biology or physics. But with all the intricate DNA unwinding and transporting and building and whatnot going on in a cell, is that screwed up if you jump up and down? Would that actually "shake up" your cells?

Is electricity produced from solar cell because light has electric and magnetic fields?

My base understanding of the solar cell is as follows: Light hits metal in solar cell and emits electron via photoelectric effect. There is n-type silicon which has an overall negative charge due to excess electrons. There is also p-type silicon which has an overall positive charge due to a...

I don't have a clear perception of how the following question is answered: "Two primary cells of emfs E1 and E2 respectively are joined in series with (i) the same polarity, and (ii) opposite polarities. The combination is connected through a galvanometer and a jockey to a potentiometer. The...

Hello everyone. I am a Hungarian born Australian theoretical/applied physicist. This is my first post on the forums. I am aware that silicon carbide crystal occurs in many different crystalline forms. I was wondering if someone here could please point me to a source that catalogs the...

it's good to aim for something impossible. so... recently, i have a lot of free time (oh, I'm only in my teens), and i would like aim to be someone who makes solar cells cheap and available, that kinda thing i know physics, like general relativity, and some quantum mechanics, recently I'm hooked...

What is the highest efficient solar cells out there? I heard there was one that is 80% efficient. And there is a clear solar cell but less efficient which are transparent ones.

Homework Statement Do fuel cell vehicles have a catalytic converter? Where is it located? The attempt at a solution[/b] I am guessing that the the question qould be referring to precious metal catalyst located at anode region which breaks the fuel into protons and electrons?

Hi, I just had 2 questions. 1. In multicellular organisms, are there any undifferentiated cells besides stem cells? Do they play any significant role? 2. Why is it that smooth ER does not have ribosomes attach to it but rough ER can have ribosomes come and attach? Is there a structural...

What I know about galvanic cells is : zinc is the anode and copper is the cathode, zinc loses electrons and it turns into ions leaving its electrons on the electrode. While copper is the cathode it also loses electrons and turns into ions leaving its electrons on the electrode, but zinc has...

Mod note: The OP has found an answer to his question. I am validating a text field in javascript in EXTJS 4 framework, based on the selected value of a text box: else if (record.get("type") === "CELL_VALUE" && record.get("apply_before") === true) { Ext.Msg.alert("Field Validation"...

I have a general question about tandem solar cells. So tandem solar cells are solar cells with multiple p-n junctions in them. However, why can't we have a single junction solar cell with multiple wavelength absorbers in them? That is to say, why do tandem solar cells need to be split...

How can I calculate the total diffused and incident light of the sun?Edit I am doing this project with solar panels. I thought, watching as well several youtube videos, that I could improve the panels with mirrors, and looking at some plants, I realized that some of their leaves bended towards...

I have undertaken a course on Semiconductors. My professor told us that a sun-solar cell system can be taken as a Carnot Engine. He assumed that the surface temperature of sun is 6000k and that of solar cell is 300k.And then he found out the efficiency by (1-T1/T2), which came out close to be...

I'm hoping to make (or model) these little cells on my own, but I'm not entirely sure how it can be done with household materials. I've seen a few videos of it being done but there's not much on how to create them. Any ideas? Thanks

With galvanic cells, we assume that the redox reaction is kinetically inhibited so that equilibrium takes a long time to reach, so we can make a good measurement of the potential difference V. I thought fuel cells were the same originally, except that we recycle in reactants and products to make...

what exactly ionizes zinc in the galvanic cell or the daniell cell ? i mean zinc atoms in the galvanic cell are ionized into Zn ++ and 2 e- . then the electrons move through the conductor to the copper bar , my question is why does zinc ionize when connected in a battery ? when the circuit...

Hello... For my biology school project, I was searching throw internet about Stem Cells in the bone marrow, that are responsible for the renewal of blood cell. I found that the bone marrow stem cells transform into red blood cells, white blood cells, monocytes... My question is how can this...

(Skip to the bottom for my questions). I'm just sounding off my thoughts above. Homework Statement Find the density of aluminum, which crystallizes in a face-centered cubic unit cell. The atomic radius is 143 pm. Homework Equations edge length of FCC is (4/sqrt2)r. The Attempt at a...

Homework Statement Above is the basic cell drawn with an object inside of it. You look in top view of the basic cell and the space around it filled with virtual cells. You can see the top view of a basic cell (the square [that is marked blue] formed by the four real mirrors with a...