Pinning, de-pinning and re-pinning of a slowly varying rivulet

The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible depinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width

Hybrid Lateral Transshipments in a Multi-Location Inventory System

In managing networks of stock holding locations, two approaches to the pooling of inventory have been proposed. Reactive transshipm nts respond to stockouts at a location by moving inventory from elsewhere within the network, while proactive redistribution of stock seeks to minimise the chance of future shocks. This paper is the first to propose a hybrid approach in which transshipments are viewed as an opportunity for stock redistribution. We adopt a quasi-myopic approach to the development of a strongly performing hybrid transshipment policy. Numerical studies which utilise dynamic programming and simulation testify to the benefits of using transshipments proactively. In comparison to a purely reactive approach to transshipment, service levels are improved while a reduction in safety stock levels is achieved. The aggregate costs incurred in managing the system are significantly reduced, especially so for large networks facing high levels of demand.

Gel electrophoresis, phase microscopy and water-holding capacity studies of beef sternomandibularis muscle treated with sodium chloride and alkaline phosphates

Beef sternomandibularis muscle (STM) was treated with various concentrations (0.10M, 0.40M, 0.70M and 1.0M) of sodium chloride (NaCl), with and without 10mM pyrophosphate (PP), and differences in myofibril swelling, myofibrillar protein extraction and water-holding capacity (WHC) were evaluated. As NaCl concentration increased, swelling of isolated myofibrils increased and reached a maximum at 1.0M NaCl. However, in the presence of 10mM PP, the NaCl concentration required to achieve maximal swelling was reduced to 0.70M NaCl;Results of gel electrophoresis revealed that as the NaCl concentration increased from 0.10M to 1.0M, the extraction of titin, myosin and other myofibrillar proteins from beef STM also increased. Furthermore, the addition of 10mM PP to NaCl solutions enhanced the extraction of myofibrillar proteins, particularly titin, from beef STM. Beef tissue WHC was increased by higher NaCl concentrations and the combination of NaCl and 10mM PP produced higher WHC values than NaCl alone;In the second study, the effects of NaCl, NaCl + 10mM PP, NaCl + 10mM tripolyphosphate (TPP) and NaCl + 10mM sodium polyphosphate glassy (SPG) were examined by treating beef STM with various concentrations (0.30M, 0.47M, 0.64M and 0.80M) of NaCl, with and without the presence of 10mM PP, 10mM TPP or 10mM SPG. Beef myofibril swelling was greater when phosphates, especially PP and TPP, were combined in solution with NaCl than when only NaCl was used;Gel electrophoresis showed that increased NaCl concentrations resulted in increased extraction of titin and myosin from beef STM. Additionally, the WHC of beef STM increased as NaCl concentration increased and the WHC was further increased when 10mM phosphates, particularly PP and TPP, were combined with NaCl. The increased beef myofibril swelling and increased beef STM tissue WHC observed in both studies was attributed to the increased extraction of a critical amount of myofibrillar/cytoskeletal protein, or to the increased extraction of a critical type of myofibrillar/cytoskeletal protein, namely titin

Accurate Analysis of Quality Properties of Software with Observation-Based Markov Chain Refinement

We introduce a tool-supported method for the automated refinement of continuous-time Markov chains (CTMCs) used to assess quality properties of component-based software. Existing research focuses on improving the efficiency of CTMC analysis and on identifying new applications for this analysis. As such, ensuring that the analysis is accurate by using CTMCs that closely model the behaviour of the analysed software has received relatively little attention. Our new method addresses this gap by refining the high-level CTMC model of a component-based software system based on observations of the execution times of its components. Our refinement method reduced analysis errors by 77–90.3% for a service-based system implemented using six public web services from three different providers, improving the accuracy of the analysis and significantly reducing the risk of invalid software engineering decisions