Asymptotic stress intensity factor density profiles for smeared-tip method for cohesive fracture

The paper presents a computational approach and numerical data which facilitate the use of the smeared-tip method for cohesive fracture in large enough structures. In the recently developed K-version of the smeared tip method, the large-size asymptotic profile of the stress intensity factor density along a cohesive crack is considered as a material characteristic, which is uniquely related to the softening stress-displacement law of the cohesive crack. After reviewing the K-version, an accurate and efficient numerical algorithm for the computation of this asymptotic profile is presented. The algorithm is based on solving a singular Abel's integral equation. The profiles corresponding to various typical softening stress-displacement laws of the cohesive crack model are computed, tabulated and plotted. The profiles for a certain range of other typical softening laws can be approximately obtained by interpolation from the tables. Knowing the profile, one can obtain with the smeared-tip method an analytical expression for the large-size solution to fracture problems, including the first two asymptotic terms of the size effect law. Consequently, numerical solutions of the integral equations of the cohesive crack model as well as finite element simulations of the cohesive crack are made superfluous. However, when the fracture process zone is attached to a notch or to the body surface and the cohesive zone ends with a stress jump, the solution is expected to be accurate only for large-enough structures.     

A VLIW processor with reconfigurable instruction set for embedded applications

This paper describes a new architecture for embedded reconfigurable computing, based on a very-long instruction word (VLIW) processor enhanced with an additional run-time configurable datapath. The reconfigurable unit is tightly coupled with the processor, featuring an application-specific instruction-set extension. Mapping computation intensive algorithmic portions on the reconfigurable unit allows a more efficient elaboration, thus leading to an improvement in both timing performance and power consumption. A test chip has been implemented in a standard 0.18-/spl mu/m CMOS technology. The test of a signal processing algorithmic benchmark showed speedups ranging from 4.3/spl times/ to 13.5/spl times/ and energy consumption reduced up to 92%.     

Quadtree based colour quantisation image compression

A new colour quantisation and quadtree based image compression scheme is proposed. The features of the new scheme are that colour palette ordering and requantisation of the decoded image for palette-based monitor displays are not required. Thus, fast decoding and displaying can be achieved     

Josephson junction with an amorphous silicon barrier

A Josephson junction Nb/Si/Nb with a 10 nm thick amorphous silicon barrier is studied. The upper electrode contains a 2 nm thick sublayer of amorphous phase adjacent to the barrier, as revealed by cross-sectional TEM. Thus, the junction can be considered as a S-I-N-S system with the N layer represented by amorphous niobium. Peculiarities in the I–V and Δ(T) dependencies are observed and explained as a consequence of a proximity effect present in the upper electrode.     

Breast cancer and benign breast disease patients evaluated in relation to oxidative stress

The 'WHO Analgesic Ladder' is a well validated approach for the selection of appropriate analgesic therapy for cancer pain as well as pain in AIDS. The mainstay of analgesic intervention for cancer and AIDS pain of moderate to severe intensity continues to be the appropriate use of opioid analgesics. There is, however, a growing appreciation for the role of adjuvant analgesics, such as antidepressants and other psychotropic medications, at each step of the WHO Analgesic Ladder, particularly in the treatment of neuropathic pain. Knowledge of the indications and usefulness of psychotropic analgesic drugs in cancer and AIDS pain populations will be most important to clinicians practicing in psycho-oncology/AIDS settings, particularly since these drugs are useful not only in the treatment of psychiatric complications of cancer and AIDS, but also as adjuvant analgesic agents in the management of pain. This paper reviews the literature on the use of antidepressants, psychostimulants, neuroleptics, anticonvulsants and other psychotropic analgesics in the management of cancer and AIDS pain. Mechanisms of analgesia, drug selection, and recommendations for clinical usage are discussed. The appropriate and timely use of psychotropic adjuvant analgesic drugs represents an opportunity for active psychiatric contribution to the multidisciplinary management of cancer and AIDS pain.     

A study of Nd2Fe14B and a neodymium-rich phase in sintered NdFeB magnets

The microstructure and properties of NdFeB sintered permanent magnets were analysed by different methods. Samples analysed were sintered and thermally treated. The hard magnetic Nd₂Fe₁₄B phase and amorphous neodymium-rich phase were observed by TEM. The neodymium-rich phase contained iron and boron, in elemental and in B₂O₃ form, which is known as a glass former. At the sintering temperature, Nd₂Fe₁₄B and the neodymium-rich phase are supersaturated with iron, which should be dissolved at the annealing temperature to react with neodymium and boron and form additional Nd₂Fe₁₄B phase. Iron precipitates of size up to 2 nm were detected in the Nd₂Fe₁₄B phase. These superparamagnetic precipitates of -Fe could affect the hard magnetic properties of NdFeB magnets.     

Performance Evaluation of Range Queries in Key Value Stores

Recently there has been a considerable increase in the number of different Key-Value stores, for supporting data storage and applications on the cloud environment. While all these solutions try to offer highly available and scalable services on the cloud, they are significantly different with each other in terms of the architecture and types of the applications, they try to support. Considering three widely-used such systems: Cassandra, HBase and Voldemort; in this paper we compare them in terms of their support for different types of query workloads. We are mainly focused on the range queries. Unlike HBase and Cassandra that have built-in support for range queries, Voldemort does not support this type of queries via its available API. For this matter, practical techniques are presented on top of Voldemort to support range queries. Our performance evaluation is based on mixed query workloads, in the sense that they contain a combination of short and long range queries, beside other types of typical queries on key-value stores such as lookup and update. We show that there are trade-offs in the performance of the selected system and scheme, and the types of the query workloads that can be processed efficiently.