Bøger af Abu Bakr El-Bediwi

The known world you know could not exist without electromagnetic energy. The term radiation refers to energy in the electromagnetic spectrum, visible light, ultraviolet light and infrared are non-ionizing radiations. Gamma rays are photons, which are type of elementary particles traveling at the speed of light with zero mass and zero charge, have much shorter wavelengths, are called ionizing radiations because they are capable of producing ions by knocking electrons out of the normal orbits of atoms or molecules. Ultraviolet light plays important part of our daily lives than most people realize, where it is a form of electromagnetic radiation with wavelength from 10 nm to 400 nm, shorter than of visible light, but longer than x-rays or it is a form of non-ionizing radiation emitted from the sun and artificial sources and its beneficial effect is production of a vitamin D. Only a few studies are available in literature about the effect of radiation on structure and antioxidants of seeds. For this reason, this book is interesting for scientist and who works in agriculture, pharmacology and bioengineering because it contains new and not available research data.

Fusible alloys are one of materials category which has attracted the attention of scientists and technologists around the world. Fusible alloys are usually eutectic mixtures of bismuth, lead, tin and cadmium. Fusible alloys melt at low temperature below 150 °C. The term fusible is used, when the alloy melts at low temperature, about the boiling water. In the past they known as Lipowitz's, Wood's, D'Arcet and Rose alloys and now they are known as Arconim's alloys. Wood's metal is the famous fusible alloy which contains 50% bismuth, 25% lead, 12.5% tin and 12.5% cadmium and melts at 70 °C. Fusible alloys are used in some fairly common items such as fire sprinkler systems in office buildings. Now other alloys having slightly different compositions in order to improve their peculiarities replaced them, because the field of applications of the mentioned alloys is extremely various. Fusible alloys are normally used in gravity casting but also lend themselves well to pressure casting and centrifugal casting methods. Bismuth alloys was primarily as laboratory interests before 1930. Bismuth alloys have very low melting temperature, low physical strength and used as solders for safe.