Improved prediction of shell side heat transfer in horizontal evaporative shell and tube heat exchangers

This paper presents an improved prediction method for the heat transfer and pressure drop in the shell side of a horizontal shell and tube evaporator. The results from an experimental test program are used in which a wide range of evaporating two-phase shell side flow data was collected from a TEMA E-shell evaporator. The data are compared with shell side heat transfer coefficient and pressure drop models for homogeneous and stratified flow. The comparison suggests a deterioration in the heat transfer data at low mass fluxes consistent with a transition from homogeneous to stratified flow. The pressure drop data suggest a stratified flow across the full test range. A new model is presented that suggests the transition in the heat transfer data may be due to the extent of tube wetting in the upper tube bundle. The new model, which also takes into account the orientation of the shell side baffles, provides a vast improvement on the predictions of a homogenous type model. The new model would enable designers of shell side evaporators/reboilers to avoid operating conditions where poor heat transfer could be expected, and it would also enable changes in process conditions to be assessed for their implications on likely heat transfer performance. (Abstract from WOK

Advances in the treatment of hereditary transthyretin amyloidosis: A review

Introduction: Amyloid transthyretin amyloidosis (ATTR) is a progressive and often fatal disease caused by the buildup of mutated (hereditary ATTR [hATTR]; also known as ATTR variant [ATTRv]) or normal transthyretin (wild-type ATTR) throughout the body. Two new therapies-inotersen, an antisense oligonucleotide therapy, and patisiran, an RNA interference therapy-received marketing authorization and represent a significant advance in the treatment of amyloidosis. Herein, we describe the clinical presentation of ATTR, commonly used procedures in its diagnosis, and current treatment landscape for ATTR, with a focus on hATTR. Methods: A PubMed search from 2008 to September 2018 was conducted to review the literature on ATTR. Results: Until recently, there have been few treatment options for polyneuropathy of hATTR. Inotersen and patisiran substantially reduce the amyloidogenic precursor protein transthyretin and have demonstrated efficacy in patients with early- and late-stage disease and in slowing or improving neuropathy progression. In contrast, established therapies, such as liver transplantation, typically reserved for patients with early-stage disease, and tafamidis, indicated for the treatment of early-stage disease in Europe, or diflunisal, a nonsteroidal anti-inflammatory drug that is used off-label, are associated with side effects and/or unclear efficacy in certain patient populations. Thus, inotersen and patisiran are positioned to be the preferred therapeutic modalities. Conclusions: Important differences between inotersen and patisiran, including formulation, dosing, requirements for premedications, and safety monitoring, require an understanding and knowledge of each treatment for informed decision making.info:eu-repo/semantics/publishedVersio

Key Technologies in Large-scale Rescue Robot Wrists

The full-Automatic Quick Hitch Coupling Device (full-AQHCD for short) is used as the starting point, key technologies in a large-scale rescue robot wrist, which is constituted by integrating a quick hitch coupling device, a turning device, and a swaying device together, are reviewed respectively. Firstly, the semi-AQHCD made domestically for the main-Arm Claw Wrist (main-ACW for short) is introduced, and the full-AQHCD imported from Oil Quick company in Sweden for the vice-Arm Cutter Wrist (vice-ACW for short) is presented. Secondly, aiming at three key technologies in the full-AQHCD including rotary joint technology, automatic docking technology and precise docking technology for quick action coupling, are concisely expressed. Thirdly, the hydraulic motor driving gear type slewing bearing technology of the turning device made domestically for the main-ACW is introduced, and the hydraulic motor driving worm type slewing bearing technology of the turning device imported from HKS company in Germany for the vice-ACW is presented, especially, the existing gap in the similar domestic technology is discussed. Subsequently, the hydraulic cylinder driving 4-bar linkage technology of the swaying device made domestically for the main-ACW is introduced, and the hydraulic double spiral swing cylinder technology of the swaying device imported from HKS company in Germany for the vice-ACW is presented, especially, the existing gap in the similar domestic technology is discussed. Finally, it is emphasized that these technological gaps have seriously restricted the ability of the vice-ACW to successfully work in future actual rescue combats, therefore, it must be highly valued in the follow-up research and development (R&D) through cooperating with professional manufacturers in China, thereby making technological advances

Herding Cats: Modelling, Simulation, Testing, and Data Mining for Weak Memory

We propose an axiomatic generic framework for modelling weak memory. We show how to instantiate this framework for SC, TSO, C++ restricted to release-acquire atomics, and Power. For Power, we compare our model to a preceding operational model in which we found a flaw. To do so, we define an operational model that we show equivalent to our axiomatic model. We also propose a model for ARM. Our testing on this architecture revealed a behaviour later acknowl-edged as a bug by ARM, and more recently 31 additional anomalies. We offer a new simulation tool, called herd, which allows the user to specify the model of his choice in a concise way. Given a specification of a model, the tool becomes a simulator for that model. The tool relies on an axiomatic description; this choice allows us to outperform all previous simulation tools. Additionally, we confirm that verification time is vastly improved, in the case of bounded model checking. Finally, we put our models in perspective, in the light of empirical data obtained by analysing the C and C++ code of a Debian Linux distribution. We present our new analysis tool, called mole, which explores a piece of code to find the weak memory idioms that it uses

"Clone Wars": Episode II - The Next Generation: The Copyright Implications relating to 3D Printing and Computer-Aided Design (CAD) Files

The future market potential of 3D printing will rest on the dissemination of Computer Aided Design (CAD) files. Without clear instructions from a CAD file, a 3D printer will not function. In fact, “a 3D printer without an attached computer and a good design file is as useless as an iPod without music”. The importance of CAD-based design files, therefore, cannot be underestimated. Drawing on UK and EU copyright laws and their application to 3D printing and CAD files, this paper will, first, question whether CAD files can be protected by copyright law before considering the copyright implications thrown up by the modification of CAD files as a result of scanning and the use of online tools. Highlighting some of the challenges for rights holders and users existent in the present law the paper advocates new business models over a premature call for stringent intellectual property laws before concluding with some recommendations for the future

Local and regional ecological morphology of dung beetle assemblages across four biogeographic regions

Aim Niche partitioning within species assemblages is thought to influence species packing and/or total niche space occupied. The evolution of dung beetles (Scarabaeinae) is likely to have been strongly influenced by inter-specific competition, leading to niche partitioning. We consider whether local-scale processes leave a signature in regional patterns of functional diversity in dung beetle assemblages, and investigate the correlation between total exploited ecomorphological space and density of species packing with increased species richness. We test whether ecomorphological space occupied by local assemblages reflects that of their regional species pool, and the extent to which ecomorphological space is convergent or divergent within functional groups across regional pools. Location Neotropics, Africa, Australia and Madagascar. Methods Dung beetle assemblages were collected in a standardized manner from four biogeographic regions. Ecomorphological similarity among the assemblages was assessed by multivariate analysis of 19 linear measurements for 300 species and three functional nesting types (roller, tunneller or dweller), firstly on a local level within the Neotropics and Afrotropics, and then between the regional species pools. Results Key body measurements, in particular the hind tibia, separated rollers and tunnellers into largely non-overlapping entities along the first three axes of the shape analysis. Three Neotropical assemblages, which vary widely in species numbers, each harboured a similar amount of morphometric variation, resulting in increasingly dense species packing with greater species richness. Similar findings were obtained in two South African assemblages. Assemblages in the four biogeographic regions showed largely similar distributions of ecomorphological variation, including the separation of rollers and tunnellers, despite their distant phylogenetic relationships. Ecomorphological similarity among regions was particularly high in tunnellers, whilst the rollers exhibited greater regional differentiation. Main conclusions Local assemblages evidently represent the full diversity of functional groups available in the regional pool, even in species-poor assemblages. There is a strong trend towards convergence in morphology separating tunnellers and rollers in phylogenetically independent lineages. The ecomorphological similarity of regional assemblages suggests that morphological convergence is the result of common selective forces active within the assemblages themselves. This lends support to the widely hypothesized effect of inter-specific interactions and niche partitioning in determining assemblage composition and lineage evolution in the Scarabaeinae. © 2011 Blackwell Publishing Ltd