Early in my teaching career I became convinced that history has value in causing the student to look at chemistry in a realistic fashion. But, like classroom demonstrations, history should fulfill a teaching objective and not be used merely as entertainment. Further, history is made by human beings and lends a human interest which is lacking when only the facts of chemistry are expounded (1). M...

and Structure of Macromolecules, Cold Spring Harbor Symposia on Quantitative Biology, vol. 28 (1963), p. 549. 3 Speyer, J., P. Lengyel, C. Basilio, A. J. Wahba, R. S. Gardner, and S. Ochoa, in Synthesis and Structure of Macromolecules, Cold Spring Harbor Symposia on Quantitative Biology, vol. 28 (1963), p. 559. 4 Doctor, B. P., J. Apgar, and R. W. Holley, J. Biol. Chem., 236, 1117 (1961). 6 Wei...

Every successful company aims to design successful products. The first phase of the design process, called product design, is therefore very important. Designers’ obligation is, for better break trough of the product on the market, to apply these demands and expectations to the developing product considering general, objective factors that have influence on design of specific product. Mechanica...

All 169 caulkers employed at a ship yard were examined to determine the prevalence of vibration syndrome due to pneumatic portable tools (chipping hammer and grinders). Vibration measurements and medical investigations were performed in the field between September 1977 and July 1978. Vibration spectra recorded on pneumatic tools were compared to ISO Draft Proposal No. 5369. The chipping hammer ...

The motion of the striking point on the piano hammer was measured before and during string contact by means of an optical equipment. The measurements resolved the motion in two perpendicular components; in the striking direction (vertical), and in the string direction (horizontal). The influence of dynamic level and touch on the hammer motion was studied. Three different types of touch were eva...

The paper introduces mathematical models of a skid steered mobile platform for robotics. The platform consists of a rectangular steel construction with four wheels. Two banks of two drive wheels on each side are linked to two DC electrical motors via chain on sprocket drive and gearing. The two drive assemblies for the left and right banks are identical but they operate independently to steer t...

The purpose of this research is to facilitate the mechanical harvesting of apricots (Prunus armeniaca L.) for industry. A tractor-trailed harvester was built to catch the fruits detached from apricot (cv. Búlida) trees by vibratory systems. This machine is a low profile catcher that can move under the trees in high-density canopies where umbrella-type harvesters cannot. The trailer is able to w...

Bone is a dense, mineral-rich tissue with organic components. Implants such as plates and nails are used to reconstruct fractures. In orthopedic surgery, broad-spectrum of drills ranges from pneumatic battery-operated electric drills. Each drill has its own set benefits drawbacks. Though the standard care, battery drill, costly, expense maintenance too high. Orthopedic surgeons frequently emplo...