Synthesis and characterization of NiPcTSTNa(L) thin films

NiPcTSTNa(L) [L = ethylenediamine (EDA); 1,4-diaminobutane (BDA); and 2,6-diamineanthraquinone (AqDA)] thin films were deposited by thermal evaporation. Their surface morphology was studied by AFM and SEM, and their chemical composition determined by EDS. Optical absorption studies of NiPcTSTNa(L) films were performed in the 200?C1150?nm wavelength range. The optical bandgap of thin films was determined from the (??h ??)^1/2 vs h?? plots for indirect allowed transitions. The temperature dependence of electrical conductivity shows a semiconducting behaviour. The amorphous semiconductor films show thermal activation energies of electrical conduction between 3·3 and 3·7?eV.     

A CONTINGENCY APPROACH TO CHOICE

The moment of choice, when a decision option is identified as being preferred, is a key stage in a decision-making process. Some explicit or implicit mechanism, be it optimising, satisficing or a combination of the two, is required to make a choice. Dependable decision-making requires an appropriate choice mechanism, but the process and criteria by which a choice mechanism is selected are seldom addressed. A contingency approach to choice is proposed in which a choice mechanism is selected according to the characteristics of the information available and the meta-level constraints and objectives of the decision-maker. Information used in the choice is characterised according to the extent and type of uncertainty. The importance in effective decision-making of meta-level requirements, for example for inclusive and transparent mechanisms, is discussed. Normative and fuzzy choice mechanisms are cast within a generic framework of choice mechanisms. A new theory of choice based on interval probabilities is introduced for use in some situations where existing theories of choice are inappropriate.     

Effects of Packaging Method, Display Light and Storage Time On The Microbial Growth and Rancidity of Fresh Pork

Effects of display light, packaging methods and storage time on total aerobic, lipolytic and proteolytic counts and oxidative rancidity of fresh pork stored at 2 ± 1° C were studied at the initial, 7th, 14th and 21st day of storage. Display light significantly increased the total aerobic psychrotroph count. Effects on lipolytic and proteolytic psychiotroph counts were not significant. No anaerobic psychrotrophs were encountered. Total and proteolytic counts of PVC film overwrapped chops and proteolytic and lipolytic psychrotroph counts of chops vacuum packaged accelerated linearly with time. Increases in lipolytic psychrotroph count of PVC packaged and total aerobic psychrotroph count of vacuum packaged chops were quadratic. TBA number and rancid odor scores were not significantly affected by treatments.     

Composition and synthesis of raphide crystals and druse crystals in berries of Vitis vinifera L. cv. Cabernet Sauvignon: Ascorbic acid as precursor for both oxalic and tartaric acids as revealed by radiolabelling studies

Biomineralisation in the fleshy pericarp of berries of Vitis vinifera L. gives rise to crystals of two distinct forms, viz. raphides and druses, which are found in exocarp and endocarp cells respectively. Druses have generally been considered as crystalline aggregates of calcium oxalate. However, the organic moiety of raphide crystals has been commonly accepted as tartrate, although we have found no analytical data to support that assumption. We now present TEM and X-ray powder diffraction analysis data showing that raphide crystals of V. vinifera berries are composed of calcium oxalate monohydrate. This work also established ascorbic acid as the biosynthetic precursor of both oxalic and tartaric acids. When ascorbic acid labelled with ¹⁴C at position 1 was introduced into berries via the rachis, 21% and 52% of the added radiolabel was recovered as oxalic and tartaric acids respectively. Purified crystals from the radiolabelled grape berries contained approximately 20% of the original radioactivity, further confirming the role of ascorbic acid in oxalic acid biosynthesis. To our knowledge, this is the first evidence to be published on the formation of oxalic and tartaric acids from ascorbic acid via two distinct pathways operating within the same physiological entity (organ).     

Gridded Aclar: preparation methods and use for correlative light and electron microscopy of cell monolayers,by TEM and FIB–SEM

Aclar, a copolymer film with properties very similar to those of tissue culture plastic, is a versatile substrate to grow cells for light (including fluorescence) and electron microscopic applications in combination with both chemical fixation and cryoimmobilization. In this paper, we describe complete procedures to perform correlative light and electron microscopy using Aclar as substrate for the culture of cell monolayers to be finally embedded in plastic. First, we developed straightforward, efficient and flexible ways to mark the surface of the Aclar to create substrates to locate cells first at the light microscopy and then the electron microscopy level. All the methods enable the user to self‐design gridded Aclar pieces, according to the purpose of the experiments, and create a large number of substrates in a short time. Second, we confirmed that marked Aclar supports the normal growth and morphology of cells. Third, we validated the correlative light and electron microscopy procedure using Aclar. This validation was done for the high‐resolution analysis of endothelial cells using transmission electron microscopy and focused ion beam–scanning electron microscopy in combination with the use of fluorescence, phase contrast and/or bright field microscopy to map areas of interest at low resolution. The methods that we present are diverse, easy to implement and highly reproducible, and emphasize the versatility of Aclar as a cell growth substrate for diverse microscopic applications.     

生物医用Ti6Al4V/xTiN复合材料的腐蚀与腐蚀磨损行为

用固相烧结法制备Ti6Al4V/xTiN(x=0,5,10,15,体积分数,％)复合材料,研究材料的腐蚀与腐蚀磨损行为及其与显微组织和显微硬度的关系.采用37℃ 和模拟体液模拟人体环境.结果表明,当TiN含量为15％时,氮(N)固溶到钛(Ti)晶格中使α-Ti稳定化,该显微组织的改变使Ti64基体的硬化效应达到58％....     

An Efficient Method for the Design of Shell and Tube Heat Exchangers

A simple, rapid, and robust algorithm for the design of segmentally baffled shell and tube heat exchangers is presented. The algorithm ensures full use of the maximum allowable pressure drops given typically as design specifications, with no geometric restrictions on the equipment. The core of the algorithm is provided by two compact formulations that relate the pressure drop for each side of the exchanger with the film heat transfer coefficient and the exchanger area. The compact formula for the tube side includes the effects of tube ends while the one for the shell side is based on the Bell-Delaware method. The parameters of the compact formulas are used as search variables in the design algorithm. Two examples are presented that show how the algorithm compares to other reported design methods and how the search for realistic solutions is aided by this method.