The Spring System: Integrated Support for Complex Real-Time Systems

The Spring system is a highly integrated collection of software and hardware that synergistically operates to provide end-to-end support in building complex real-time applications. In this paper, we show how Spring's specification language, programming language, software generation system, and operating system kernel are applied to build a flexible manufacturing testbed. The same ingredients have also been used to realize a predictable version of a robot pick and place application used in industry. These applications are good examples of complex real-time systems that require flexibility. The goal of this paper is to demonstrate the integrated nature of the system and the benefits of integration; in particular, the use of reflective information and the value of function and time composition. The lessons learned from these applications and the project as a whole are also presented.     

转子热表面引起感应电动机内可燃蒸气的点燃

普通开户式和全封闭外壳扇冷电动机已用于分类（危险）场所２区几十年了。ＩＥＥＥＰ１３４９工作组（危险场所电动机）,正在制订１类,２区场所用电动机的一个“推荐方案”。他们产生了一个疑问,即如果感应电动机转子很热,能否安全地用于分类的（危险）场所。ＡＰＩ（美国石油协会）出版物２２１６“在露天中因热表面点燃碳氢蒸气的危险”,断定,在露天中热表面上的蒸气被点燃需要的温度,要高出实验室确定的（ＡＳＴＭＥ６５９）物质最低点燃温度很多（至少２００℃）才行。本报告验证了ＡＰＩ出版物的假设用到感应电动机内热表面上的正确性。几台各种规格的电动机配以热电偶,用仪器连接起来,将自燃温度低的（如（二）乙醚、庚烷、乙烷,四氟乙烯）可燃性浓度物质注入电动机内部,各台电动机承受一组短时转子制动试验,这时转子表面温度按规定的增高级差,处于物质的自     

The Scientific Prototype, a Proposed Next Step for the American MFE Program

The “Scientific Prototype” is a tokamak about the size and power of JET, TFTR or JT-60, but which runs steady state in DT and breeds its own tritium. This paper, more in the spirit of an editorial than a scientific research publication, argues that it is the only reasonable option for the American MFE program.     

Evaluating Enzymatic Productivity—The Missing Link to Enzyme Utility

Kinetic productivity analysis is critical to the characterization of enzyme catalytic performance and capacity. However, productivity analysis has been largely overlooked in the published literature. Less than 0.01% of studies which report on enzyme characterization present productivity analysis, despite the fact that this is the only measurement method that provides a reliable indicator of potential commercial utility. Here, we argue that reporting productivity data involving native, modified, and immobilized enzymes under different reaction conditions will be of immense value in optimizing enzymatic processes, with a view to accelerating biotechnological applications. With the use of examples from wide-ranging studies, we demonstrate that productivity is a measure of critical importance to the translational and commercial use of enzymes and processes that employ them. We conclude the review by suggesting steps to maximize the productivity of enzyme catalyzed reactions.     

Plasmonic Electrically Functionalized TiO2 for High‐Performance Organic Solar Cells

Optical effects of the plasmonic structures and the materials effects of the metal nanomaterials have recently been individually studied for enhancing performance of organic solar cells (OSCs). Here, the effects of plasmonically induced carrier generation and enhanced carrier extraction of the carrier transport layer (i.e., plasmonic‐electrical effects) in OSCs are investigated. Enhanced charge extraction in TiO₂ as a highly efficient electron transport layer by the incorporation of metal nanoparticles (NPs) is proposed and demonstrated. Efficient device performance is demonstrated by using Au NPs incorporated TiO₂ at a plasmonic wavelength (560–600 nm), which is far longer than the originally necessary UV light. By optimizing the concentration ratio of the Au NPs in the NP‐TiO₂ composite, the performances of OSCs with various polymer active layers are enhanced and efficiency of 8.74% is reached. An integrated optical and electrical model, which takes into account plasmonic‐induced hot carrier tunneling probability and extraction barrier between TiO₂ and the active layer, is introduced. The enhanced charge extraction under plasmonic illumination is attributed to the strong charge injection of plasmonically excited electrons from NPs into TiO₂. The mechanism favors trap filling in TiO₂, which can lower the effective energy barrier and facilitate carrier transport in OSCs.     

Role of Polyamine-Induced Dimerization of Antizyme in Its Cellular Functions

The polyamines, spermine (Spm) and spermidine (Spd), are important for cell growth and function. Their homeostasis is strictly controlled, and a key downregulator of the polyamine pool is the polyamine-inducible protein, antizyme 1 (OAZ1). OAZ1 inhibits polyamine uptake and targets ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis, for proteasomal degradation. Here we report, for the first time, that polyamines induce dimerization of mouse recombinant full-length OAZ1, forming an (OAZ1)₂-Polyamine complex. Dimerization could be modulated by functionally active C-methylated spermidine mimetics (MeSpds) by changing the position of the methyl group along the Spd backbone—2-MeSpd was a poor inducer as opposed to 1-MeSpd, 3-MeSpd, and Spd, which were good inducers. Importantly, the ability of compounds to inhibit polyamine uptake correlated with the efficiency of the (OAZ1)₂-Polyamine complex formation. Thus, the (OAZ1)₂-Polyamine complex may be needed to inhibit polyamine uptake. The efficiency of polyamine-induced ribosomal +1 frameshifting of OAZ1 mRNA could also be differentially modulated by MeSpds—2-MeSpd was a poor inducer of OAZ1 biosynthesis and hence a poor downregulator of ODC activity unlike the other MeSpds. These findings offer new insight into the OAZ1-mediated regulation of polyamine homeostasis and provide the chemical tools to study it.     

Genetic Tuning of Iron Oxide Nanoparticle Size,Shape, and Surface Properties in Magnetospirillum magneticum

Different applications require iron oxide nanoparticles (IONPs) of varying size, shape, crystallinity, and surfaces that can be controlled through the synthesis reaction conditions. Under ambient conditions, Magnetospirillum magneticum AMB-1 builds uniform Fe₃O₄ IONPs with shapes and crystal forms difficult to achieve with chemical synthesis. Genetic engineering can be used to change their properties, but there are few tools to fine-tune expression over a wide range. To this end, ribosome binding sites, minimal constitutive promoters, and inducible systems (IPTG, aTc, and OC6) with large dynamic range are designed. These are used to control M. magneticum genes that affect IONP properties, including size (mamC), morphology (mms6), chain length (mamK), and surface coating (mamC fusions). These systems increase the fraction of IONPs that are less than 30 nm, produce rounded particles, and lead to the production of intracellular chains with 24 or more IONPs. In addition, the R5 peptide from diatoms is found to silica coat the surface of metal oxide nanoparticles (Fe, Ti, Ta, Hf) and can be genetically directed to the IONP surface. This work demonstrates the genetic control of IONP properties, but also highlights the robustness of the system, which complicates genetic engineering to produce radically different particles and structures.     

Utility-scale subsurface hydrogen storage: UK perspectives and technology

To reduce effects from anthropogenically induced climate change renewable energy systems are being implemented at an accelerated rate, the UKs wind capacity alone is set to more than double by 2030. However, the intermittency associated with these systems presents a challenge to their effective implementation. This is estimated to lead to the curtailment of up to 7.72 TWh by 2030. Through electrolysis, this surplus can be stored chemically in the form of hydrogen to contribute to the 15 TWh required by 2050. The low density of hydrogen constrains above ground utility-scale storage systems and thus leads to exploration of the subsurface.This literature review describes the challenges and barriers, geological criteria and geographical availability of all utility-scale hydrogen storage technologies with a unique UK perspective. This is furthered by discussion of current research (primarily numerical models), with particular attention to porous storage as geographical constraints will necessitate its deployment within the UK. Finally, avenues of research which could further current understanding are discussed.