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Wheat is one of the most important cereal crops. It covers the largest area under any single crop in the world. It feeds about 40 % of the world's population and provides 20 % of the caloric and protein requirements in human nutrition. Wheat also occupies a central position in maintaining world's food security. Following incorporation of semi-dwarfing genes, wheat production doubled in the 1960s, an era called the Green Revolution. The Green Revolution resulted in the development of semi dwarf wheat cultivars that were highly responsive to inorganic fertilizer application, were early maturing and resistant to lodging. Semi dwarf cultivars also remained resistant to various diseases for many decades. Wheat genetic gains are less than 1 % per annum which are not sufficient to meet the future food demand of ever increasing human population. This chapter addresses importance, history, production and utilization of wheat from different perspectives. [ABSTRACT FROM AUTHOR]

Chapter 12 of the book "How to Choose and Use Bench Planes and Scrapers" is presented. It explores on the choices of blades, which are the most critical part of the planes. It mentions about steel to be deceptive and considers the facts of its chemical compositions, manufacturing process, and the hardness. It highlights on different planes made up of two part blade system including the actual iron and an attached steel called cap iron, with a dome-head machine screw to the plane.

The machining of complex shaped designs was difficult earlier, but with the advent of the new machining processes incorporating in it chemical, electrical & mechanical processes, manufacturing has redefined itself. This paper intends to deal with one of the revolutionary process called Electro Chemical Machining (ECM) which is unconventional process. New materials which have high strength to weight ratio, heat resistance and hardness and also complex shapes and need for accuracy demand newer type of machining process. These processes are called unconventional machining processes. ECM removes material without heat. Almost all types of metals can be machined by this process. In today's high precision and time sensitive scenario, ECM has wide scope of applications. The said paper is a experimental study of effect of voltage variation on MRR for Stainless steel EN Series 58A (AISI 302B) A comparative study of calculation for MRR on theoretical as well practical basis are given in tabular format with graphical representation. The said experimentation is carried out at Micromachining Cell I I T Bombay in the month of Dec 2008. [ABSTRACT FROM AUTHOR]

Hard turning is the latest technology and is used to turn hard materials by using cutting tools like CBN and PCBN. Certain hard materials like titanium, Inconel and stainless steel are pronounced as difficult to cut materials. The superior cutting tools effectively machine such hard materials and produces desirable surface roughness with less tool wear. The present research was carried on hard Cr -Mo alloy steel namely SCM 440 material by turning process. The hardness of the work materials were maintained between 45 to 55 HRC. The CBN produced low surface roughness and PCBN tool produced high surface roughness. The formation of crater wear was less in PCBN tool than CBN tool. Build up layer (BUL) was due to diffusion of work material on CBN and PCBN tools. PCBN tool withstand heat better than CBN. Formation of built up edge (BUE) is concern on PCBN tool and is less than CBN tool. [ABSTRACT FROM AUTHOR]

Chapter 6 of the book "The Fundamentals of Corrosion and Scaling for Petroleum and Environmental Engineers," by George V. Chillingar, Ryan Mourhatch, and Ghazi D. Al-Qahtani is presented. It discusses the different scales in measuring the hardness and alkalinity of water that produces scale formation in oil well equipment which includes mineral scales of calcium carbonate and sulfate. It mentions that sodium polyacrylate polymers, amino-phosphates and phosphate esters of amino-alcohols can inhibit the scale formation.

All that is, at all, Lasts ever, past recall, Earth changes, But thy soul and God stand sure, Time's wheel runs back or stops: Potter and clay endure. Of all the different types of material, ceramics might be the most difficult to define. Many would regard them as falling in a small and rather restricted group, and the only examples that come readily to mind would probably be bathroom fixtures, tiles, and the insulators in spark plugs and on telephone poles. The term ceramic actually covers a large variety of natural and artificial substances that share the desirable qualities of hardness and resistance to heat, electricity and corrosion. Just how large and how important the ceramic domain is can be gauged by some of its members: stone, brick, concrete, sand, diamond, glass, clay and quartz. If there has been a lack of understanding of ceramics, it is excusable because even dictionary definitions tend to be rather narrow. We find them restricted to either pottery or porcelain in most cases, and even the better efforts usually go no farther than ‘products of industries involving the use of clay or other silicates’. The word ceramic actually comes from the Greek word keramos, which means burnt stuff. This is too broad a term to be useful here. The best working definition uses a combination of chemical and physical criteria. [ABSTRACT FROM AUTHOR]

Deep in unfathomable mines Of never failing skill He treasures up his bright designs And works his sovereign will The way in which the world came into being, and the time of this important event, have of course been the subject of frequent speculation down through the ages. The issue reveals an interesting schism between oriental and occidental philosophies. The Hindus, for instance, have long maintained that the Earth has existed for thousands of millions of years. In sharp contrast to this, we have the views of Archbishop Ussher and Dr Lightfoot, who, in the middle of the seventeenth century, made a systematic scrutiny of the Bible. They found that a consistent chronological sequence could be established and were able to announce that creation commenced promptly at 9 am on Sunday, 23 October, in the year 4004 BC. The remarkable fact is that this result continued to be taken seriously until not much more than a hundred years ago. And there are many who still believe it. The various scientific methods that have been brought to bear on the question during the past century have successively increased the estimates of the age of the Earth and its neighbouring planets. One can now state, with reasonable confidence, that the solar system is about 6000 million years old. This makes it between a third and a half the age of the Universe itself. [ABSTRACT FROM AUTHOR]

The spurt in research activities pertaining to nanotechnology, much interest has arisen in processes involving severe plastic deformation. Equal channel angular pressing (ECAP) in particular has drawn considerable attention due to its potential to produce ultrafine-grained or in some cases nanometer grain size materials in bulk form. It is now well known that materials with such small grain sizes have extraordinary properties and, such as simultaneous ultrahigh strength and high ductility as well as the capability of superplastic forming. They therefore have great potential for technological applications. Equal channel angular extrusion (ECAE) was used to investigate the formation of submicron grain in copper deformed to ultra-high plastic strains by die angle of 90°. The mechanical result was characterized by the use of tensile tests, microhardness measurement Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC). ECA extrusions at room temperature result in a significant reduction of grain size due to a fragmentation of the preexisting coarse grains. In TEM, many grains are separated by high-angle boundaries. For the specimen deformed N = 2, A drop of the hardness level was observed at 573 K, indicating that a fully recrystallized state was achieved. [ABSTRACT FROM AUTHOR]

Compressibility or hardness of objects is an important aspect in haptic perception. Both cutaneous and kinaesthetic information are used for the perception of compressibility. In this paper, the relative role of these contributions is investigated. This is done with psychophysical experiments using a purpose-made silicon rubber stimulus set. The fabrication and characterisation of the stimuli are described, as well as discrimination experiments with and without surface deformation of the stimuli. With the cutaneous cues of surface deformation present, the Weber fraction for hardness discrimination was 0.12. When surface deformation was removed and only kinaesthetic cues were available, the Weber fraction doubled, suggesting that the cutaneous sense contributes almost three quarters to hardness perception, and the kinaesthetic just over one quarter, if the information is integrated in a statistically optimal fashion. [ABSTRACT FROM AUTHOR]

In the cross country skiing community, hot wax treatment of the ski running surface (SRS) is used in order to influence the surface hardness of the skis in relation to the hardness of the snow crystals. This is discussed in a number of scientific papers and recommended in almost every ski waxing manual. The general idea is to decrease (soften) the surface hardness by the use of a soft glide wax treatment for wet snow conditions and to increase (harden) the hardness of the surface by a hard (synthetic) glide wax treatment for cold, dry snow conditions. The question is; does the hot glide wax treatment of the ski running surface influence the surface hardness? And if so, in what way? In our experiment, ski base specimens of UHMWPE (transparent and ˵graphite″) were treated with ski glide wax. Half of the specimens were treated with soft yellow glide wax, and half with hard green glide wax. After the wax treatment, the surface hardness (Shore D) was measured with a durometer. The study revealed that: both soft glide wax and hard glide wax treatment make the SRS softer; after a long immersion (12 hours) in the bath of melted glide wax, both the hardness of the specimens treated with soft glide wax and of those treated with hard glide wax decreased significant. Conclusion: The hot wax treatment of the SRS with available glide waxes cannot make the SRS harder than it was initially (unwaxed). [ABSTRACT FROM AUTHOR]

A chapter from the book "Pocket Nature: Rocks and Minerals" is presented. It teaches how to identify a mineral by its properties such as colour, streak, hardness, and density. Colour, lustre, and streak are properties visible to the eye, others such as hardness and radioactivity need to be measured using simple equipment. Crystal forms and systems, and a table of chemical elements and their symbols are also provided.

Radiation caries is stated after tumor therapeutic irradiation of the head-neck area. An expression of this is the disintegration up to a complete tooth loss. Different kinds of therapy aim to stop this disintegration. In this study, 3 different methods of tooth conservation using fluorides have been examined on their effect on the mechanical properties of the teeth. In the first method the remineralization took place after the cumulative dose of 60 Gy had been applied, in the second one, the remineralization took place before each dose und in the third one during the irradiation. [ABSTRACT FROM AUTHOR]

Chapter 4.1 of the book “Introduction to Molecular Motion in Polymers" is presented which explores the transition of glass to rubber. It discusses mechanical properties such as hardness and softness, elastic recovery of the original shape, and vibration damping and energy loss and moduli like linear elastic or Young's modulus and shear modulus. It also mentions the acoustic properties of polymer materials and the use of polymeric materials as electrical insulators.

A chapter from the book "Skateboarding: Learn to Skate Like a Pro!" is presented. It discusses the wheels on a skateboard including location, levels of hardness and composition. It examines the different aspects of the hardness of a skateboard wheel including how to measure hardness and the effects of number readings.