Point Dynamic Loads on a Sandwich Structure

Russian Engineering Research - The action of dynamic point loads on a three-layer structure with fiberglass filler is studied experimentally. The experimental data are compared with theoretical...     

A high-sensitivity Hall magnetometer

Based on two Hall transducers, a low-frequency magnetometer with a sensitivity of 2.5 × 10^–3 G/Hz^1/2 is designed. The dynamic range of the magnetometer at a frequency of 19 Hz varies from 2.5 × 10^–3 to ±8 × 10⁴ G.     

Some Studies on Starch Carbamate

Starch carbamate was prepared by reacting maize starch with urea using solid state technique. The different factors affecting this reaction were studied. These factors include urea concentration, type of starch, reaction and duration. The carbamate extent and carbamation reaction efficiency (%) were traced by estimating the nitrogen content of the reaction product. Solubility, viscosity and total ester content of starch carbamate samples were estimated. The carbamate extent increases by increasing urea concentration as well as reaction temperature and duration. Increasing the reaction temperature and duration has the same effect on carbamation reaction efficiency (%), while increasing urea concentration do the reverse. The solubility (%) of starch carbamate samples depends on urea concentration, reaction temperature and duration as well as the type of starch used. The maximum solubility obtained was 63% and 43% for starch carbamate derived from pregelled and native starch, respectively. Tentative mechanism for the reaction between starch and urea has been proposed.     

Photo-Thermal-Elastic Interaction in a Functionally Graded Material (FGM) and Magnetic Field

Silicon - In this work, we aim to investigate the photo-thermal-elastic waves interaction in a nano-composite semiconductor, elastic and functionally graded material (FGM). The governing equations...     

半固态铝合金汽车动力零件的疲劳分析模型开发（英文）

汽车悬架控制臂被用来连接转向节和车架,其主要功能是在加速和制动的装载和脱载的疲劳应力作用下提供稳定性。一般情况下,这些零件采用钢材制备,导致油耗量和污染气体排放量增加。最近,有研究尝试研发更轻、更耐疲劳的半固态A357铝合金以取代钢质悬架控制臂。本研究旨在更好地理解运用数学模拟识别疲劳应变强化参数,以便确定铝合金悬架控制臂的疲劳特性。最佳的方法是对标准试样进行疲劳测试,然后以循环次数分别作为应力和变形的函数,绘制两条Wohler曲线。利用这些曲线和特定的数学分析方法,可以得到所有的参数。计算出的新参数表明,与同一合金的相同分析曲线相比,A357铝合金样品的实验疲劳曲线明显改善。     

Manufacture of magnetic circuits of axial welding equipment

Advanced technologies of producing magnetic circuits for axial welding transformers are discussed. The technologies proposed by the authors are characterized by the efficient utilization (almost without waste) of electrical engineering material, simple procedure and universal nature, high degree of automation and continuous technological process stages.     

Specific Features of the Transition of Amorphous Al87REM5Ni8(Fe) Alloys Into the Crystalline State Under the Influence of Temperature

Materials Science - We determine the kinetic parameters of crystallization of amorphous metallic alloys based on aluminum doped with rare-earth metals (REM) by the method of differential scanning...