CONCENTRATION AND DETERMINATION OF GRADE IN TESTS ON SILLIMANITE IN IDAHO SCHIST*

Laboratory batch tests have demonstrated that the Idaho sillimanite schist was amenable to beneficiation by common ore-dressing methods. The minable schist, containing an average of about 7.8%, sillimanite, was crushed to pass 35 mesh and concentrated by a combination of tabling and flotation. Grade was determined by petrographic examination of fractions obtained by heavy-liquid separations in a centrifuge. This method was used as a positive means of separating the sillimanite from the gangue minerals. Photomicrographs illustrate the character and quantity of sillimanite in the various concentration products.     

超临界CO2透平机主轴冷却装置静动态特性分析

以超临界二氧化碳(SCO2)透平机主轴冷却装置为研究对象,基于流体域圆柱曲面展开法建立了流体域压力分布的数学模型,推导出压力分布及承载力的函数表达式;采用CFD分析方法,针对进气压力、主轴转速、偏心率等不同条件下的流场压力、承载力、刚度进行了分析研究.研究结果表明:主轴低速对气膜压力影响极小,轴向压力以冷却装置轴向中心...     

Additive Manufacturing of Engineered Living Materials with Bio-Augmented Mechanical Properties and Resistance to Degradation

Engineered living materials (ELMs) combine living cells with polymeric matrices to yield unique materials with programmable functions. While the cellular platform and the polymer network determine the material properties and applications, there are still gaps in the ability to seamlessly integrate the biotic (cellular) and abiotic (polymer) components into singular materials, then assemble them into devices and machines. Herein, the additive-manufacturing of ELMs wherein bioproduction of metabolites from the encapsulated cells enhanced the properties of the surrounding matrix is demonstrated. First, aqueous resins are developed comprising bovine serum albumin (BSA) and poly(ethylene glycol diacrylate) (PEGDA) with engineered microbes for vat photopolymerization to create objects with a wide array of 3D form factors. The BSA-PEGDA matrix afforded hydrogels that are mechanically stiff and tough for use in load-bearing applications. Second, the continuous in situ production of l -DOPA, naringenin, and betaxanthins from the engineered cells encapsulated within the BSA-PEGDA matrix is demonstrated. These microbial metabolites bioaugmented the properties of the BSA-PEGDA matrix by enhancing the stiffness (l -DOPA) or resistance to enzymatic degradation (betaxanthin). Finally, the assembly of the 3D printed ELM components into mechanically functional bolts and gears to showcase the potential to create functional ELMs for synthetic living machines is demonstrated.