Network Coding on Heterogeneous Multi-Core Processors for Wireless Sensor Networks

While network coding is well known for its efficiency and usefulness in wireless sensor networks, the excessive costs associated with decoding computation and complexity still hinder its adoption into practical use. On the other hand, high-performance microprocessors with heterogeneous multi-cores would be used as processing nodes of the wireless sensor networks in the near future. To this end, this paper introduces an efficient network coding algorithm developed for the heterogenous multi-core processors. The proposed idea is fully tested on one of the currently available heterogeneous multi-core processors referred to as the Cell Broadband Engine

Institutional case volume and mortality after aortic and mitral valve replacement: a nationwide study in two Korean cohorts

Background : There are only a handful of published studies regarding the volume-outcome relationship in heart valve surgery. We evaluated the association between institutional case volume and mortality after aortic valve replacement (AVR) and mitral valve replacement (MVR). Methods : Two separate cohorts of all adults who underwent AVR or MVR, respectively, between 2009 and 2016 were analyzed using a Korean healthcare insurance database. Hospitals performing AVRs were divided into three groups according to the average annual case volume: the low- ( 70 cases/year). Hospitals performing MVRs were also grouped as the low- ( 40 cases/year). In-hospital mortality after AVR or MVR were compared among the groups. Results : In total, 7875 AVR and 5084 MVR cases were analyzed. In-hospital mortality after AVR was 8.3% (192/2318), 4.0% (84/2102), and 2.6% (90/3455) in the low-, medium-, and high-volume centers, respectively. The adjusted risk was higher in the low- (OR 2.31, 95% CI 1.73–3.09) and medium-volume centers (OR 1.53, 95% CI 1.09–2.15) compared to the high-volume centers. In-hospital mortality after MVR was 9.3% (155/1663), 6.3% (94/1501), and 2.9% (56/1920) in the low-, medium-, and high-volume centers, respectively. Compared to the high-volume centers, the medium- (OR 1.97, 95% CI 1.35–2.88) and low-volume centers (OR 2.29, 95% CI 1.60–3.27) showed higher adjusted risk of in-hospital mortality. Conclusions : Lower case volume is associated with increased in-hospital mortality after AVR and MVR. The results warrant a comprehensive discussion regarding regionalization/centralization of cardiac valve replacements to optimize patient outcomes

Academic and Personal Problems Among Australian University Students Who Drink at Hazardous Levels: Web-Based Survey

Issue addressed: Australian university students consume large amounts of alcohol. There is little published information about personal and academic problems associated with this behaviour. We sought to estimate the prevalence, and identify variables associated with, alcohol-related problems among undergraduate hazardous drinkers. Methods: The control group members (942 undergraduates, 53.3% male, mean age 19.4 years) of an internet-based intervention trial, who scored 8 on the Alcohol Use Disorders Identification Test, completed two validated questionnaires about their experience of alcohol-related problems in the preceding 4 weeks. Regression models were used to identify associations between individual characteristics and alcohol-related problems. Results: One-quarter of participants had missed a class (25.6%) and/or had been unable to concentrate in class (25.7%), and 45% reported that their drinking had impacted negatively on their learning or grades. The most frequent non-academic problems were hangovers (74.8%), blackouts (44.8%), emotional outbursts (30.5%), vomiting (28.1%), arguments (20.2%) and drink-driving (23.2%).Male gender, lower age, being a smoker, being in the Faculty of Health (versus Humanities) and living in shared housing (versus with parents/guardians) were each associated with alcohol-related problems, whereas year of study had no association. Conclusions: There is a high prevalence of preventable alcohol-related problems among undergraduates drinking at hazardous levels and a need for restriction of the availability and promotion of alcohol as well as intervention for individuals at high risk. So what? Universities have a duty of care to large populations of young people drinking at hazardous levels and should make greater efforts to address hazardous alcohol consumption

Isolation and characterization of bacteriophages for avian pathogenic E. coli strains

Aims: To isolate and characterize bacteriophages, and to evaluate its lytic performance against avian pathogenic Escherichia coli (APEC) strains with high patterns of antibiotic resistance, in order to select phages for a therapeutic product to treat colibacillosis in chickens. Methods and Results: Bacteriophages were isolated from poultry sewage and tested against 148 O-serotyped APEC strains. The morphological characterization of the bacteriophages was made by transmission electronic microscopy (TEM) observations and the genetic comparison between bacteriophages DNA was performed by restriction fragment length polymorphism (RFLP) patterns. Results showed that 70·5% of the tested E. coli strains were sensitive to a combination of three of the five isolated phages, that seemed to be virulent and taxonomically belong to the Caudovirales order. Two of them look like 16–19, T4-like phages (Myoviridae) and the third is a T1-like phage and belongs to Syphoviridae family. All of them are genetically different. Conclusions: It was possible to obtain a combination of three different lytic bacteriophages with broad lytic spectra against the most prevalent O-serotypes of APEC. Significance and Impact of the Study: Data reported in this study, presents an in vitro well studied phage product to be used as antimicrobial agent to treat colibacillosis in poultry industry.Fundação para a Ciência e a Tecnologia (FCT

Development of Ni- and Fe- based catalysts with different metal particle sizes for the production of carbon nanotubes and hydrogen from thermo-chemical conversion of waste plastics

Co-production of valuable hydrogen and carbon nanotubes (CNTs) has obtained growing interest for the management of waste plastics through thermo-chemical conversion technology. Catalyst development is one of the key factors for this process to improve hydrogen production and the quality of CNTs. In this work, Ni/SiO2 and Fe/SiO2 catalysts with different metal particle sizes were investigated in relation to their performance on the production of hydrogen and CNTs from catalytic gasification of waste polypropylene, using a two-stage fixed-bed reaction system. The influences of the type of metals and the crystal size of metal particles on product yields and the production of CNTs in terms of morphology have been studied using a range of techniques; gas chromatography (GC); X-ray diffraction (XRD); temperature programme oxidation (TPO); scanning electron microscopy (SEM); transmission electron microscopy (TEM) etc. The results show that the Fe-based catalysts, in particular with large particle size (∼80 nm), produced the highest yield of hydrogen (∼25.60 mmol H2 g−1 plastic) and the highest yield of carbons (29 wt.%), as well as the largest fraction of graphite carbons (as obtained from TPO analysis of the reacted catalyst). Both Fe- and Ni-based catalysts with larger metal particles produced higher yield of hydrogen compared with the catalysts with smaller metal particles, respectively. Furthermore, the CNTs formed using the Ni/SiO2-S catalyst (with the smallest metal particles around 8 nm) produced large amount of amorphous carbons, which are undesirable for the process of CNTs production

Research on Dimensionless Unit Hydrograph and Time of Concentration for Maryland Watersheds

SHA/UM/5-04Observed data from 100 rainfall-runoff events on 54 watersheds in Maryland and Delaware were used to investigate two watershed characteristics: the dimensionless unit hydrograph (DUH) and time of concentration (Tc). Streamflow hydrograph data were obtained from US Geological Survey gaging stations. Event hyetographs were generated from US Weather Service NEXRAD Radar Stage III data (DPR) using a method developed in this study. The gamma-function form of the Natural Resources Conservation Service unit hydrograph was assumed. For each event, an optimization method was used to determine the time to peak and gamma parameter (related to the Peak Rate Factor, PRF) that give the best-fit direct runoff hydrograph when convolved with the rainfall excess hyetograph. Tc was estimated by differentiation of the unit hydrograph. Efforts to predict PRF and Tc using watershed properties, and to update an existing regression equation, were inconclusive. Future investigations will focus on improving the event baseflow separation and determination of rainfall excess

Dynamic shading systems: A review of design parameters, platforms and evaluation strategies

The advancements in software and hardware technologies provide opportunities for solar shading systems to function dynamically within their context. This development has helped dynamic shading systems respond to variable environmental parameters such as sun angles and solar insolation. However, the technical understanding of system design, mechanism and controlling methods presents a challenge for architects and designers. Therefore, this study aims to review the current applications and trends of dynamic shading systems to clarify the potentials and limitations in enhancing system performance based on integrated design objectives. This study assessed several systems on the basis of a critical review to identify different models, applications and methodologies. This study is divided into two main sections: (i) design elements and platforms that engage with specific methods in creating a dynamic shading system and (ii) evaluation strategies to examine system performance. The systems were investigated based on the multiplicity and integration of the parameters involved through various components, such as architectural, mechanical, operational and automation components. The review analysed various studies on the following two bases: (1) geometric-based analysis, which distinguishes between simple and complex shading models, and (2) performance-based analysis, which assesses the shading systems based on two groups of methodologies, namely, theoretical and experimental. The outcome of the review reflects a clear classification of shading models and a comprehensive analysis of their performance. This study generally provides a systematic framework for architects based on thorough research and investigation. Finally, the study introduced several findings and recommendations to improve the performance of dynamic shading systems

A review of photovoltaic module technologies for increased performance in tropical climate

The global adoption and use of photovoltaic modules (PVMs) as the main source of energy is the key to realising the UN Millennium Development Goals on Green Energy. The technology – projected to contribute about 20% of world energy supply by 2050, over 60% by 2100 and leading to 50% reduction in global CO2 emissions – is threatened by its poor performance in tropical climate. Such performance discourages its regional acceptance. The magnitude of crucial module performance influencing factors (cell temperature, wind speed and relative humidity) reach critical values of 90 °C, 0.2 m/s and 85%, respectively in tropical climates which negatively impact module performance indices which include power output (PO), power conversion efficiency (PCE) and energy payback time (EPBT). This investigation reviews PVM technologies which include cell, contact and interconnection technologies. It identifies critical technology route(s) with potential to increase operational reliability of PVMs in the tropics when adopted. The cell performance is measured by PO, PCE and EPBT while contacts and interconnections performance is measured by the degree of recombination, shading losses and also the rate of thermo-mechanical degradation. It is found that the mono-crystalline cell has the best PCE of 25% while the Cadmium Telluride (CdTe) cell has the lowest EPBT of 8-months. Results show that the poly-crystalline cell has the largest market share amounting to 54%. The CdTe cell exhibits 0% drop in PCE at high-temperatures and low irradiance operations – demonstrating least affected PO by the conditions. Further results establish that back contacts and back-to-back interconnection technologies produce the least recombination losses and demonstrate absence of shading in addition to possessing longest interconnection fatigue life. Based on these findings, the authors propose a PVM comprising CdTe cell, back contacts and back-to-back interconnection technologies as the technology with latent capacity to produce improved performance in tropical climates