Localization of vitamin A in the small intestine of mouse. An electron microscope radioautographic study

Localization of vitamin A in the small intestine of mice was studied with electron microscope radioautography after administration of tritiated vitamin A. The label was concentrated over lipid droplets in cells distributed in the lamina propria and the submucous layer. The cells were similar both to fibroblasts and to fat-storing cells in their morphological features. The name "Vitamin A-Storing Cell" is proposed for these labeled cells, including the fat-storing cell in the liver.     

Step slider bearing with viscoelastic lubricant

The performance of an idealized step slider bearing with a viscoelastic lubricant is investigated theoretically. The elasticity of the lubricant is characterized by a dimensionless number α. The effects of the elasticity of the lubricant on the pressure, load-bearing capacity, frictional resistance, coefficient of friction and maximum film thickness were studied in detail and are presented in several graphs and tables.     

A Petri Net based approach to determine the disassembly strategy of a product

In order to protect the environment and regain value added to products, a process known as disassembly has come into the limelight. This process is to be applied to reuse abandoned goods and materials. Manufacturers are being forced to establish disassembly plants and to develop their products' designs so as to maintain the government's dictate to dispose off their products in an environmentally responsible manner. This research presents a cost-based heuristic analysis for a circuit board assembly. Various components of the product and their assembly relationships are represented by a Petri Net diagram. Firing the transitions of the disassembly Petri Net is integrated with cost-based indices to develop an effective disassembly strategy. The methodology discussed here simplifies the decisionmaking process involved in disassembly planning. A comprehensive disassembly process planning system is proposed here and is exemplified by a case study of circuit board assembly.     

Single step synthesis of GdAlO3 powder

A novel method for preparation of nano-crystalline gadolinium aluminate (GdAlO₃) powder, based on combustion synthesis, is reported. It was observed that aluminium nitrate and gadolinium nitrate exhibit different combustion characteristics with respect to urea, glycine and β-alanine. While urea was proven to be a suitable fuel for direct formation of crystalline α-Al₂O₃ from its nitrate, glycine and β-alanine are suitable fuels for gadolinium nitrate for preparation of its oxide after combustion reaction. Based on the observed chemical characteristics of gadolinium and aluminium nitrates with respect to above mentioned fuels for the combustion reaction, the fuel mixture composition could be predicted that could lead to phase pure perovskite GdAlO₃ directly after the combustion reaction without any subsequent calcination step. The use of single fuel, on the other hand, leads to formation of amorphous precursor powders that call for subsequent calcination for the formation of crystalline GdAlO₃. The powders produced directly after combustion reactions using fuel mixtures were found to be highly sinterable. The sintering of the powders at 1550 °C for 4 h resulted in GdAlO₃ with sintered density of more than 95%. T.D.     

GPC Profile Change of Potato Starch with Extrusion Processing

Native potato starch (moisture content 15%) was treated by twin screw extruder under four operating conditions with varying barrel temperatures (110°C–230°C). These modified starch samples were compared to native and drum-dried starch. Starch sample solution for gel chromatography was prepared by the three methods (acidic, alkaline, and neutral methods). They were subjected to gel chromatography on Toyopearl HW-75, and some difference was found among the three gel chromatographic patterns obtained from the same starch solution. This discrepancy among GPC patterns suggests formation of some types of anhydro-bonds between chains of amylopectin and or amylose in the extrusion process. Elevating barrel temperature increases degree of depolymerization. The size of fragments formed with the treatment is bigger than that of oligosaccharides but smaller than that of amylose.     

High-temperature characteristics of 1.3-μm InAsP-InAlGaAs ridgewaveguide lasers

High-temperature characteristics of InAsP-InAlGaAs strained multiquantum-well (MQW) lasers with a large conduction band discontinuity (ΔE_c) are demonstrated. The InAsP-InAlGaAs MQW ridge waveguide lasers with narrow stripes exhibited a characteristic temperature as high as 143 K in the range from 25°C to 85°C. This material system is promising for developing a cooling-system-free 1.3-μm laser     

Scanning electron microscopy of food-poisoning bacterium Bacillus cereus using a variable-pressure SEM

A variable-pressure scanning electron microscopy (VP-SEM) with a cooling stage permits long hours of observation of water-containing specimens in their natural or close to natural state, without the conventional specimen preparations of fixation, dehydration, drying and metal coating. It reduces water vaporization and beam damage by keeping the specimens at a low temperature. We observed Bacillus cereus colonies on nutrient agar, which would shrink significantly if any conventional specimen preparation technique were used. We also studied the growing process of the bacteria on raw and steamed rice using the VP-SEM without conventional preparation techniques. Original specimens were directly mounted onto specimen holders and their backscattered electron images observed under the following conditions: specimen stage temperature, -10 degrees C; specimen chamber vacuum level, 30-70 Pa; and accelerating voltage, 15-20 kV. We recognized that the VP-SEM minimized deformation of the colonies due to shrinkage of the nutrient agar, and successfully imaged the morphology of the colonies and bacteria without a decline in bacteria number, which is apt to occur during fixation and dehydration. Also, the growth process of the bacteria on raw or steamed rice could be observed promptly, since there is no specimen preparation step.