Talreja payhnu Shaid

One of the most important tests in engineering is knowing when an object or material will bend or break, and the property that tells us this is the Young’s modulus. It is a measure how easily a material stretches and deforms.

Wires obey Hooke’s law, just like springs do. When a force F is applied, it will extend some distance x, which can simply be described by the equation F = kx

Whereas k for a spring is the spring constant, the amount of extension for a wire depends on its cross sectional area, length, and the material it is made from. The Young’s modulus (E) is a property of the material that tells us how easily it can stretch and deform and is defined as the ratio of tensile stress (σ) to tensile strain (ε). Where stress is the amount of force applied per unit area (σ = F/A) and strain is extension per unit length (ε = dl/l).

Since the force F = mg, we can obtain the Young’s modulus of a wire by measuring the change in length (dl) as weights of mass m are applied (assuming g = 9.81 metres per second squared).

Is Young's modulus relevant to research?

For different types of materials, the stress-strain plots can look very different. Brittle materials tend to be very strong because they can withstand a lot of stress, they don’t stretch very much and will break suddenly. Ductile materials have a larger elastic region where the stress-strain relationship is linear, but at the first turnover (the elastic limit), the linearity breaks down and the material can no longer return to its original form. The second peak, is the ultimate tensile strength and it tells us the maximum stress a material can withstand before breaking. Plastic materials are not very strong but can withstand a lot of strain. Young's modulus is given by the gradient of the line in a stress-strain plot.

In the experiment in the video above, we measured the Young’s modulus of some copper wire which does not extend very much. So a fiducial marker such as some tape can be used to help identify the original and extended lengths. Making multiple measurements with a variety of masses will increase the number of points on the stress-strain plot and make the calculation of Young's modulus more reliable. Another thing to take care of is measuring the cross-sectional area of the wire. Imperfections of the wire may mean that the diameter is not perfectly constant along its length, so taking the mean of several readings with the micrometer could help.

Studying of the mechanical properties of materials is important because it helps us understand how materials behave, and allows us to develop new products and improve existing ones. One example research topic at Birmingham looked at developing vaulting poles used by high jump athletes to maximise performance. These poles need to be light to allow a fast run-up, but also must be able to store elastic strain energy as the pole bends. The pole has to convert elastic energy to kinetic energy as the pole straightens out, and be able to withstand the stress caused by the weight of the vaulter - and withstand repeated uses by the athlete.

On small scales, there are many products that contain biological (e.g. pharmaceutical drugs, fertility treatments, tissue engineering) and non-biological microparticles (e.g. chemicals, agriculture, household care). Through understanding their mechanical properties we can predict their behaviour in manufacturing and processing, maximise their performance capabilities.

The Young's modulus of a material is a useful property to know in order to predict the behaviour of the material when subjected to a force. This is important for almost everything around us, from buildings, to bridges to vehicles and more.

Select an image, layer, or area. Choose Filter > Adjustments > Equalize. If you selected an area of the image, select what to equalize in the dialog box, and click OK: Equalize Selected Area Only to evenly distribute only the selection's pixels.

If you’re sick of stale air and weeping windows, but don’t know where to start, we’re here to help. Follow these steps, in conjunction with using our database, to narrow your options and find the best ventilation system for your home.

You should only opt for a ventilation system if you’ve installed floor and ceiling insulation (if possible) as well as a decent heat source. In living areas this should be a fixed, efficient source of warmth, such as a heat pump or wood burner. In smaller rooms, portable plug-in electric heaters are sufficient.

Identify any sources of airborne moisture, such as bathrooms, then consider installing a shower dome or extractor fan. Also look at fitting a plastic moisture control sheet to stop rising damp, and check if water is pooling under the home from any blocked drains.

If problems persist, you can opt for a mechanical ventilation system, but note these cost upwards of $2000 (installed). A dehumidifier is a cheaper stopgap solution, but will cost more to run than a ventilation system.

The first thing to consider when looking at ventilation systems is whether you should go for positive pressure or balanced pressure – don’t confuse either with heat transfer systems.

Ventilation systems filter the air coming from your roof space or the outdoors. There are a wide array of filter types, usually designated by a letter and a number (for example, G4). In general, “F” filters remove smaller particles than “G” filters, so will catch more dust and airborne bacteria. The higher the second number, the more effective the filter – for example, an F7 filter will catch more nasties than an F6 filter. Some manufacturers offer optional advanced filters: carbon filters can be good for removing odours from the air (for example, the smell of everyone blasting their wood burner on a cold winter day), while HEPA filters are claimed to be effective at removing allergens. We recommend going for the standard filter initially, and only adding a carbon or HEPA filter if you find you’re dealing with odours indoors or suffering from allergies.

Some systems offer the ability to add heaters to ducting, which can be useful for positive pressure systems if you’re concerned about cool air from the roof space reducing indoor temperatures. Summer cooling options, where the ventilation system introduces cooler air to the home, are available but can be expensive.

Winter condensation is a widespread problem. In winter we spend more time indoors, creating moisture from cooking, cleaning, washing and even breathing. When we're out of the house we leave it closed up for security.

Insulation adds to the problem. We trap the heat of living areas by keeping doors shut and using heavy curtains and carpets.

This all comes at a price. Warm air holds water better than cold air. Because it's sealed in, the moisture builds up then condenses on cold surfaces such as windows and walls.

The solution is simple – better ventilation. Making it happen is less simple.

If you're living in a draughty old Victorian villa, you shouldn't have too much of a problem with ventilation. But modern houses are much more airtight, so natural ventilation is minimal.

Extra heating is part of the solution, combined with water extraction near the sources. Rangehoods intercept steam from the kitchen; extractor fans are effective at drying out bathrooms. You could also consider a dehumidifier. While these can help control condensation, they’re expensive to run (up to $2.50 a day), often noisy, and must be run constantly. With a dehumidifier you are controlling the symptoms and not dealing with the problem. While not the ideal solution, dehumidifiers have their place.

An automatic ventilation system is a better way of controlling condensation. Whichever way you attack the problem, remember it's even more effective if the amount of water released into the air is reduced.

• Launch DBX File Viewer.
• You can open an existing Outlook Express identity.
• Or select and open any DBX file.
• You can also perform a DBX file search.
• You can view the messages and perform an email search.
• Double-click on a message to open it in your default email client.

• On the Google Fi website, go to Your plan.
• Select the device that you would like to discontinue enrollment for.
• Under "Device protection," select Discontinue. On the next screen, select Discontinue again.