General knowledge

What is Thermal Imaging and How does it Works?

Thermal Imaging is a method of using infrared radiation and thermal energy to gather information about objects, in order to formulate images of them, even in low visibility environments. It’s a type of technology that has built up a broad range of uses over the years. In particular, it’s an effective form of night-vision technology, with the capability to work in the total absence of any light (since it doesn’t rely on visible light), and can even work in smoke, fog, smog and haze. Thermal imaging is based upon the science of infrared energy (otherwise known as “heat”), which is emitted from all objects. This energy from an object is also referred to as the “heat signature”, and the quantity of radiation emitted tends to be proportional to the overall heat of the object.
Thermal cameras or thermal imagers are sophisticated devices comprised of a sensitive heat sensor with the capacity to pick up minute differences in temperature. As they gather the infrared radiation from objects in a particular environment, they can start to map out an image based on the differences and inflexions of the temperature measurements.

"কিন্তু সেটিই শেষ কথা নয়, সেটি ট্র‍্যাজেডিও নয়। সে মহৎ কিছু করছে না, তার দারিদ্র্য যাচ্ছে না, তার অভাব মিটছে না, কিন্তু তা সত্ত্বেও সে জীবনবিমুখ হচ্ছে না। সে পালাচ্ছে না, escape করছে না। সে বাঁচতে চাইছে। সে বলছে, বাঁচার মধ্যেই সার্থকতা, তার মধ্যেই আনন্দ, He wants to live!"

The end of an era. 💔

বাংলা সাহিত্যের এবং মুভিতে কবিতা আবৃত্তিতে অনেক কিছু শিখার মত কন্টেন্ট রেখে গেলেন তিনি।

What is use of Calcium Carbide in fruits?

Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green (typically "redder"), and softer as it ripens.
Ripening agents accelerate ripening. An important ripening agent is ethylene, a gaseous hormone produced by many plants. Many synthetic analogues of ethylene are available They allow many fruits to be picked prior to full ripening, which is useful since ripened fruits do not ship well. For example, bananas are picked when green and artificially ripened after shipment by being exposed to ethylene.
Calcium carbide is also used in some countries for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is similar in its effects to the natural ripening agent, ethylene. Acetylene accelerates the ripening process. Catalytic generators are used to produce ethylene gas simply and safely. Ethylene sensors can be used to precisely control the amount of gas. Covered fruit ripening bowls or bags are commercially available. These containers increase the amount of ethylene and carbon dioxide gases around the fruit, which promotes ripening.
Ripening indicators like Iodine (I) can be used to determine whether fruits are ripening or rotting by showing whether the starch in the fruit has turned into sugar. For example, a drop of iodine on a slightly rotten part (not the skin) of an apple will stay yellow or orange, since starch is no longer present. If the iodine is applied and takes 2–3 seconds to turn dark blue or black, then the process of ripening has begun but is not yet complete. If the iodine becomes black immediately, then most of the starch is still present at high concentrations in the sample, and hence the fruit hasn't fully started to ripen.