This paper presents an approach for teaching and learning dc-dc converter design using MathCAD. MathCAD provides advantages that greatly improve teaching and learning process especially when long and complicated design equations are involved such as those found in dc-dc converters. A design example using Excel is presented and then compared with the same example using MathCAD. Experience learne...

Step-up dc-dc converters have to cope with extremely low input voltages when used in combination with energy harvesting sources like thermogenerators, inductive generators or solar cells. The presented dc-dc converter is characterized by a high efficiency, up to 70 % in the input voltage range between 200 mV and 500 mV, and a minimum start-up voltage of 70 mV. It can deliver an output power of ...

trichomoniasis is one of the most common urinary-genital tract disease. the causal agent of trichomoniasis is flagellate protozoan called trichomonas vaginalis. metronidazole and tinidazole are the drug of choice for treatment. carcinogenic and embryo-teratogenic effects of the mentioned drugs and resistance to metronidazole has been reported. according to cytotoxic effects of medicinal herbs i...

Leyland's cypress (xCupressocyparis leylandii) is a putative, spontaneous hybrid between Chamaecyparis nootkatensis and Cupressus macrocarpa. To investigate this putative origin, twenty five Leyland's cypresses were sampled, along with living, putative parents of Ch. nootkatensis and Cup. macrocarpa from gardens in the UK. The DNA was extracted and analyzed by DNA fingerprinting (RAPDs) and Int...

Leaf tissues of aurea mutants of tobacco and Lespedeza have been shown to have higher photosynthetic capacity per molecule of chlorophyll, a higher saturation intensity, a simpler lamellar structure, and the same quantum yield as their dark green parents. Here we report on the values of photosynthetic units for both types of plants and some algae. The unit has been assumed to be about as unifor...

Fur color that differs from the typical shades of brown and gray occurs in eight species of marmots. Albinism generally is rare whereas melanism is more common. Melanism may persist in some populations at low frequencies averaging 16.1% in M. monax and in M. flaviventris for as long as 80 years. White (not albino) and “bluish” marmots generally are rare, but a population of white M. marmota per...