Chlorophyll in plant cells is regularly accompanied by other pigments. For many years there has been speculation as to whether the light absorbed by these so called accessory pigments is utilized for photosynthesis. Engelmann's skillful experiments (1883) on algae of various colors, with motile bacteria as an indicator of photosynthetic activity, have been the basis of a general belief that the...

The calculation of absorbed dose from internally incorporated radionuclides is based on the so-called specific absorbed fractions (SAFs) which represent the fraction of energy emitted in a given source region that is absorbed per unit mass in a specific target organ. Until recently, photon SAFs were calculated using MIRD-type mathematical phantoms. For electrons, the energy released was assumed...

In recent years, wood fibres have often been applied as the reinforcement of thermoplastic materials, such as polypropylene, whereas their use in combination with thermosetting resin has been less widespread. This study concerns the production of PMMA-based composites by partly replacing alumina trihydrate (ATH) with wood waste fillers, namely rice husks and almond shells, which would otherwise...

aluminum foams are a novel branch of advanced materials with superior properties. sandwich structures with aluminum foam core are good energy absorbers. in this paper, mechanical properties and energy absorption of aluminum foam sandwich panels subjected to quasi-static perforation tests with conical-nosed indenter were investigated experimentally. for this purpose sandwich panels consisting of...

an energy based damage index based on a new nonlinear finite element (fe) approach applicable to rc structures subjected to cyclic, earthquake or monotonic loading is proposed. the proposed method is based on the evaluation of nonlinear local degradation of materials and taking into account of the pseudo-plastic hinge produced in the critical sections of the structure. a computer program is dev...