Harvesting Definition and 43 Threads

There has been much discussion about how could we (theoretically) extract energy from the accelerated expansion of the universe. However, the only gedankenexperiment I can found is the "tethered galaxies" one (e.g. https://arxiv.org/abs/astro-ph/0104349). However, has somebody proposed an...

- design of a micro-turbine based on different scenarios of waterfalls - build a system that involves a battery for storing power - test in the lab I have attached a image. I know the image is not very detailed but wanting some advice on this situation. I have done some water calculations on...

I have two questions: 1) Is it possible to cut the material with a laser cutter or scissors or do I need to have a specific tool? 2) What is the best way to attach the PZT-5H material to the beam but it can be easily detached for using it on another beam ( so no epoxy glue)?Thank you

I was enjoying my (very short) hot shower this morning and realized that the lovely warm water was flowing over my body (sorry - too much information) only once and then disappearing down the drain. This water - and what comes out of the washing machine, dishwasher etc. could be at a seriously...

I want to do RF energy harvesting simulation for the measurement of Power Conversion Efficiency. So how can be simulation done on a single platform?. Kindly suggest

Assume that a contraption with loosely suspended internal weights is fixed to the body of a vehicle that is moving in free 3D space without gravitational sources nearby. Given the position and orientation of the vehicle as functions of time, how can one tell whether it is possible for the...

Hello. I have a question related to capacitance. here is another mechanical solution to harness wave energy. Can changing capacity of the capacitor be used to harness wave energy? Let's say we envelope conductive plates in plastic and submerge them in the ocean and the water in between them...

Hello there :) if there were an energy converter for a motorway where 5000000 cars drive over it annually and that has an efficiency of 100 percent, how many kWh does the energy converter give me? The energy converter would generate 4000 joules / s per pass. (P = 1400 * 9.81 * 0.02 / 0.07)...

Hi, I have to make a report on an energy harvesting system using piezolectric materials by comparing two methods each other which are: the standard technique (rectifier bridge+filtering capacitance) and the nonlinear technique, by adding to the standard device a switch and an inductor in...

Hello! What are the available methods to harvest rotational energy? I was thinking to put a turbine on the shaft and compress air, but the air will get cold and the energy will be lost. I was thinking to put an electric generator, which is ok but it needs a battery. I was thinking to use...

Hello everyone (and sorry for my average english), I have to make a report on an energy harvesting system from vibrations with piezoelectric elements. During my research, i always read that there two cases in a piezoelectric harvesting system which are : weakly coupled strucutre and strongly...

What do you guys think of this concept. https://www.sciencedaily.com/releases/2017/09/170926125154.htm

Hi! Can anyone help me? If a constant number h of fish are harvested from a fishery per unit time, then a model for the population P(t) of the fishery at time t is given by: dP/dt = P(5-P) - h, P(0) = P0. a. Solve for the IVP if h = 4. b. Determine the value of P0 such that the fish...

Hello, I am an student of Engineering and I come a cross of a doubt that I would like to investigate a bit more. I would like some information or some directions to the right path for the following. I would like to know how could I calculate the harvesting energy of an area for a piezoelectric...

So I've noticed my little sister's helium balloons floating at the ceiling. Made me wonder if someone could create a device that could harvest energy from this buoyancy. What if I tied a very long rope to a huge balloon filled with helium, and rolled the other end of the rope to a gear attached...

why can't we go for harvesting hydropower from the pipelines, eventhough the flow is not continuous we can generate and store it,,, and can use it for small devices..

How difficult would it be to harvest the electrical out put of 8 small 3 volt motor/generator?

Hi guys, I was just thinking about something and I'd love to get your opinion. How much energy do you think is lost from water pipes getting hot and releasing that energy into the air? In a three bedroom house there are probably a lot of hot pipes releasing heat energy. Do you think some sort...

Hello, I'm an Aquaculture Engineering student at lima. I'm trying to do an experiment of electrochemical harvesting of microalgae. But it seems my weakness at physics its getting in the way plus i don't know to well how to operate the equipment which none knows either since its new to the lab. I...

Hi there... I have an application where I know the vibration frequency/force/acceleration of the source... How can I find the maximum theoretical power output (in mw/watts...) of a tuned piezo where its resonance is the same as the source vibration frequency...

An article by the University of Waterloo talks about Quantum Entanglement Harvesting and possible novel applications, such as using it to probe the structure of spacetime: https://uwaterloo.ca/institute-for-quantum-computing/news/entanglement-harvesting-vacuum So I understand that Spacetime...

Hey Physics Forum! So I will try to give as much detail as possible and needed without dragging on. We have an RF source at 5.8 GHz producing -17dBm and we eventually amplify it close to 27dBm (so we get as close to 30dBm out of source antenna as possible). We are using 5.8 GHz slot antennas...

Hi I have a really weird idea that is robbing me of my sleep. One of the many problems with fusion seems to be how to harvest the energy released by the reaction efficiently. So as I was slowly drifting into sleep I was wondering, how we usually harvest energy from reactions, and the piston...

So, personally, I'm really excited about having wireless energy harvesting. I was looking up articles on piezoelectrics, since that seems to be the leading thing these days, and I encountered an article that designed a MEMS circuit (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3958224/). It's...

Hello! I'm new to this website, so apologies if I'm a little off with the way I format this question. Nonetheless: This last year, I've been researching sound energy and methods of focusing, harvesting, and storing this energy. Essentially, I'm looking at the possibility of harnessing sound...

Hello, I am looking for harvesting piezo elements with the greatest possible power output. Can someone give me some links to manufacturers and/or articles and books, please? Thanks in advance.

So I was thinking about something today. Tell me if it's possible. I don't care if its plausible, just physically possible. Somehow, we design a huge solar panel that is extremely resistant to heat. We send it out on a trajectory towards the sun, coming very close before being pulled into an...

Radial Artery harvesting is becoming and more and more used as an option for bypass surgery. I have read that there is an increase in the risk of pour tissue oxygenation, which of course makes sense. You can read more in - http://lib.tmd.ac.jp/jmd/5202/01_manabe.pdf, where it is also referred...

Hello, I've been toying with the idea of making a cheap dynomometer for small electric motors, but one of the obstacles I'm encountering is finding a cheap load cell. The best I've done so far is a $75 sensor from Omega, which still requires conditioning. Then it occurred to me that you can...

Homework Statement I only need help with problem 16 but included problem 15 because it is referenced in problem 16. 16. Suppose that the growth-rate parameter k = 0.3 and the carrrying capacity N = 2500 in the logistic population model of Excercise 15. Suppose p(0) = 2500. (a) If 100...

Could a gyro be able to harvest the energy from the Earth rotation? If the gyro is locked in space, it must change position relative to the alignment of the earth. This change in position could be the energy output. A gear mechanism is taking energy from the rotating Earth to keep the gyro...

hi I am doing project on piezoelectric energy harvesting which is a cantilever structure using COMSOL. I have some doubts related to my project. I designed cantilever structure having three layers substrate (SiC), piezo (ZnO) and electrode (Al). My doubt is that when piezoelectric layer...

So, this may sound like a homework question but I promise it's not. How much energy do you think could be harvested per human step? For instance, if you had "buttons" in the bottom of shoes which compressed a spring and somehow moved that energy to some sort of energy storage device, how much...

using the proper orbital mechanics, could a megaton nickel/iron asteroid be soft landed on Earth without the use of heat shields?

Here's a new and interesting design for a nuclear reactor which I've never seen before: http://www.rbsp.info/rbs/RbS/PDF/aiaa05.pdf It's harvesting the kinetic energy of fission fragments via magnetic fields, converting it directly into electrical energy. They say that past obstacles over...

Here is the question: Investigate the harvesting model in problem 5 both qualitatively and analytically in the case a=5, b=1, and h=25/4. Determine whether the population becomes extinct in finite time. If so, find that time. The information from problem 5 is: dP/dt= P(a-bP)-h ...

A little gizmo with one heckuva claim was demonstrated at the Consumer Electronics Show (CES) recently. The Airnergy by RCA claims to be able to scavenge enough energy from WiFi (and presumably the 2.4GHz band) to juice up its own internal battery and allow a user to charge up devices on the...

Radio-frequency Harvesting THE INDUCTION SYSTEMS are only the beginning. Some of the most visually arresting examples of wireless electricity are based on what's known as radio frequency, or RF. While less efficient, they work across distances of up to 85 feet. In these systems, electricity...

Hi all, I just looked at a thread involving a wind turbine on a car or something of that sort and I have a similar idea... but it does not involve a car. It is similar in the aspect of something creates energy , and you add something else to it to get more energy, but I'm not sure if the...

Homework Statement Hi guys! I am trying to show the limiting population for this model:Homework Equations P'(t) = P(S - P) + H The harvesting, is actually immigration, so its a positive unknown. I have shown this before (without harvesting) by solving for P(t) using separation of variables...

There is a lot of talk about big projects to gather energy from wind. I have two ideas I don't see used that I was wondering about. 1. Using large stretches of canvas to redirect wind from a large cross sectional area to a smaller outlet, like some kind of wind nozzle. It would also form...

While exploring the information on biodiesel, it became clear that the feedstock for this all around. As it turns out, blue-green algae - cyanobacteria, or pond scum - is a good producer of hydrocarbons. Knowing that lichen is made from cyanobacteria and fungus, and considering the abudance of...

Are stem cells (used in research) derived from frozen embryos from people who wish to do in vitro fertilization?