bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric Study of Cascade Latent Heat Thermal Storage System for Concentrating Solar Power Plants
Authors: Xu Ben , Zhao Yawen , Chirino Hermes , Li Peiwen
Published: August 2017

Recently, Concentrated Solar Power (CSP) is attracting more research attentions because it can store the excessive heat from the solar field and extend the power generation at night, CSP can also levelized the mismatch between energy demand and supply. To make CSP technology competitive, thermal energy storage (TES) system filled with energy storage media is a critical component in all CSP plant.

TES system can be operated by using sensible materials, phase change materials (PCMs) or a combination of both. Because the phase change materials can store more heat due to the latent during the melting/freezing process, it becomes promising to use PCM in latent heat thermal energy storage (LHTES) system for large scale CSP application. Unfortunately, LHSS has relatively low energy storage efficiency compared to SHSS alone because of the fact that LHSS has more parameters to be controlled and optimized.

To realize a complete utilization of PCM and a high energy storage/extraction efficiency and a high exergetic efficiency, one approach is to adopt a cascade configuration of multiple PCMs modules in TES tank, which can also be called as a cascade latent heat thermal energy storage (CLHTES) system. The melting temperatures of the PCMs placed in the TES tank should be cascaded from low to high temperature, where the latent heat of PCM can completely be used to absorb the heat from the solar field for energy storage purpose.

Due to the complexity of a CLHTES system, it is necessary to provide a comprehensive study from the heat transfer perspective. This paper presents a preliminary parametric study of CLHTES system using a previously developed enthalpy-based 1D transient model for energy storage/extraction in CLHTES system. The effects of material properties (such as latent heat, specific heat at solid and liquid phase) and CSP plant operation conditions (such as charging/discharging time period) are to be explored. The results from the preliminary parametric study is expected to be beneficial to the community of solar thermal engineering.
Peak-Shaving Ratio Analysis of the Natural Gas Combined Heat and Power Plant With Distributed Peak-Shaving Heat Pumps
Authors: Zhao Xiling , Wang Xiaoyin , Sun Tao
Published: August 2017

Distributed peak-shaving heat pump technology is to use a heat pump to adjust the heat on the secondary network in a substation, with features of low initial investment, flexible adjustment, and high operating cost. The paper takes an example for the system that uses two 9F class gas turbines (back pressure steam) as the basic heat source and a distributed heat pump in the substation as the peak-shaving heat source. The peak-shaving ratio is defined as the ratio of the designed peak-shaving heat load and the designed total heat load. The economic annual cost is taken as a goal, and the optimal peak-shaving ratio of the system is investigated. The influence of natural gas price, electricity price, and transportation distance are also analyzed. It can provide the reference for the optimized design and operation of the system.
Feasibility Assessment of Low-Volume Anaerobic Digestion Systems for Institutional Food Waste Producers
Authors: Win Shwe Sin , Hegde Swati , Chen Roger B. , Trabold Thomas A.
Published: August 2017

Anaerobic digestion (AD) has gained popularity as an effective way to treat organic materials, produce clean energy, and reduce greenhouse gas emissions. There is a significant number of large-scale AD facilities operating world-wide, largely treating livestock wastes, and used primarily for electricity production in industrialized countries. At the same time, there are millions of small, household-scale ADs deployed in developing countries, mostly to provide biogas resources for heating and cooking. Decentralized low-volume AD systems could provide a local, renewable energy source (for electricity, heating, or both), reduce or eliminate waste disposal costs, and limit discharges of high strength wastes. The purpose of this study was to evaluate the feasibility of deploying low-volume anaerobic digestion (LVAD) systems at institutions generating significant food waste, using Rochester Institute of Technology (RIT) as a case study. Mass flows and energy balance, net present value (NPV), and discounted payback period (DPP) were used to assess the feasibility of implementing an anaerobic digestion system utilizing the campus organic waste resources. Our study showed that a positive NPV can be achieved if subsidies and incentives were applied to offset the initial capital investment. However, the economics can be improved by driving down equipment cost and accepting food waste from other establishments to generate revenue from tipping fees.
Effect of Multi Injection Process on “Zeolite Boiler” in Thermochemical Energy Storage and Transport System of Unused Heat From Bagasse Boiler
Authors: Fujii Shoma , Kanematsu Yuichiro , Kikuchi Yasunori , Nakagaki Takao
Published: August 2017

In the sugar mill in Tanegashima which is an isolated island in Japan, raw sugar production process produces raw sugar and bagasse simultaneously. Raw bagasse is not storable because of its perishability due to high moisture content. Actually, the bagasse boiler burns more bagasse than that is required for the sugar mill. Hence, the temperature of flue gas increases and a massive amount of unused heat at around 200 °C is exhausted during sugar mill operation period. On the other hand, many other factories in this island burn imported oil at package boilers to generate process steam up to 120 °C all year around. To resolve this spatial and seasonal mismatch, we employed thermochemical energy storage and transport system using zeolite steam adsorption and regeneration cycle. We introduced a basic design of heat release device which is called “Zeolite boiler”, that is a moving bed with indirect heat exchanger. Adsorbed steam is assumed to be generated by a package boiler. A small zeolite boiler with 20 kg/h of zeolite was designed by using a developed quasi-2D simulation code that numerically solves mass and heat conservation equations of the counter-flow reactor model. As the result of single injection from the top of chamber, the zeolite boiler could generate 4.95 kg/h of dry saturated steam at 0.2 MPa when 4.0 kg/h of steam was injected from the package boiler. Multi injection process was considered to improve the heat recovery rate. By injecting 3.0 kg/h and 1.0 kg/h of steam separately from the top and the middle of the chamber, 5.9 kg/h of steam was generated and heat recovery rate was increased by 13 points.
Optimization of a Small Size CHP System by Means of a Fully Transient Numerical Approach
Authors: Chiantera Luigi , Milani Massimo , Montorsi Luca , Stefani Matteo
Published: August 2017

The paper investigates the performance of a combined heat and power system by means of a fully dynamic numerical approach. An ad-hoc library for the simulation of energy conversion systems is developed under the OpenModelica open source platform; the library includes the main components that usually equip a Combined Heat and Power (CHP) system and they can be connected as they are logically connected in the real plant. Each component is modelled by means of equations and correlations that calculate their performance on a time dependent basis. Therefore, many configurations can be evaluated not only in terms of cumulative annual results or average performance, but the instantaneous behavior can be investigated. The numerical library is constructed using the lumped and distributed parameter approach and it is validated by comparing the numerical results with the measured values over a one-year time period. The prediction capabilities of the proposed numerical approach are evaluated by simulating a case study of a health spa. This case study is selected since it is characterized by significant requirements of both thermal and electric energy. The comparison demonstrated that the calculated results are in good agreement with the measurements in terms of both annual values and distribution over the reference period.

Furthermore, an optimization algorithm is adopted and linked to the developed library in order to estimate the best size of different components of the CHP system according to a number of constraints. This feature is particularly important when addressing the energy efficiency of a complete system that is depending on a number of interdependent variables. Therefore, the case study is investigated by accounting also for additional technologies that can be further enhance the performance of the system both in terms of energy consumption and economic investment. In particular, the numerical model is used to optimized the CHP energy efficiency by estimating the best trade-off between the reduction of the energy purchased and the overall cost of the system. The application of PV panels and electric energy accumulators is also investigated and the simulation demonstrates that the size of the cogeneration unit equal to 48 kW, the number of PV panels of 299 and the battery capacity of 45 kWh provide the lowest amount of energy purchased, while the best return of investment is obtained by the CHP unit of 40 kW along with 109 PV panels and a battery of 40 kWh.
Numerical Study of the Effect of a Biodiesel on the Cylinder Liner of Compression Ignition Engine
Authors: Nwaiwu Chidiebere F. , Nwufo Olisaemeka C. , Igbokwe Johnson O. , Ogueke Nnamdi V. , Anyanwu Emmanuel E.
Published: August 2017

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion chamber experienced the greatest temperature rise in comparison to other parts of the liner. These results show that though there are lots of publications confirming that a compression ignition engine previously running on diesel fuel can run on biodiesel fuel or its blend with diesel, there is a need for a further critical study on the development of engine parts like the cylinder liner.
Design and Development of a Battery Internal Short Circuit Test Machine
Authors: DeLaney Scott C. , Burbules Mary B. , Garg Mayank , Hollinger Adam S. , Rahn Christopher D.
Published: August 2017

The use of lithium-based batteries, due to their high energy density, has become popular for power sources in portable electronic devices. Safety concerns over lithium cell applications have arisen due to their lower abuse tolerance compared to standard battery designs. Internal short circuits present one of the more dangerous abuse situations since there is a great potential of thermal runaway leading to fire and explosion. Field failures and recalls associated with internal short circuits demonstrate the risks of lithium batteries. Understanding the response of lithium cells under internal short circuit conditions is of great importance to ensure the safe development of lithium battery application. In this work, an internal short circuit test machine was designed to conduct nail penetration tests of lithium chemistry cells. The test machine successfully provides the required force to allow for multi-cell penetration. The test machine also provides accurate control of the penetrating nail’s position and velocity. This testing will support the development of models to simulate the mechanism of internal short circuits of lithium cells.
Dynamic Modeling of a Flat-Plate Photovoltaic/Thermal Collector
Authors: Li Xuan , Al-Alili Ali
Published: August 2017

To investigate the performance of photovoltaic/thermal (PV/T) collectors, the steady-state model is not sufficient. Therefore, a dynamic model of the PV/T collector is required to capture the PV/T electrical and thermal output variation throughout the day. This article presents a dynamic model of a water type flat-plate PV/T collector. The model can be used to carry out in depth analysis of the PV/T transient thermal and electrical performance. It is developed based on the energy analysis of each component of the PV/T collector. The energy balance equations are solved by employing an explicit Runge-Kutta method using MATLAB program. The model is then validated with an experimental work. The thermal and electrical performance of a certain PV/T collector on a typical summer day is investigated under the hot and humid weather conditions of Abu Dhabi, the United Arab Emirates. A parametric study is also performed in order to study the effect of various parameters, namely: the inclination angle of the PV/T collector, the thermal conductance of the adhesive layer between the PV cells and the absorber plate, and the water mass flow rate.
Detailed Dynamic Model of an Institutional Building in Hot and Humid Climate Conditions
Authors: Bin Masood Junaid , Hussain Sajid , AlAlili Ali , Zaidan Sara , Al Hajri Ebrahim
Published: August 2017

This paper is an ASHRAE Level 3 study of the energy audit process carried out in an institutional building, The Umm Shaif Building, of The Petroleum Institute, Abu Dhabi, UAE. It undertakes the study by collecting data and conditional surveys. The energy loss locations are highlighted through psychrometric and infrared camera analysis. The detailed dynamic model has been simulated using the EnergyPlus® simulation engine. The details of the building envelope, and fenestration, the occupancy schedules, the equipment energy consumption and HVAC details are presented. The detailed building model is used to allocate the energy usage and identify key energy consumers. The main results are reported using monthly total energy consumption. The validation and calibration are performed through different statistical metrics including Coefficient of Determination (R2), Root Mean Square Error (RMSE) and Coefficient of Variance Root Mean Square Error (CVRMSE). Finally, energy conservation measures are suggested with the energy and cost savings.
Wind Turbine Drivetrain Test Bench Capability to Replicate Design Loads: Part I — Evaluation Methodology
Authors: Giguère Philippe , Wagner John R.
Published: August 2017

The utilization of a ground-based testing facility for full-size wind turbine drivetrains is growing. Several test benches have been developed to apply torque and non-torque loads. These mechanical loads can be the loads used to design the drivetrain components or loads obtained from field measurements. Irrespective of the reason for testing a drivetrain, the selected test bench should have the capability to impose the loads of interest. The design of these test benches and their capabilities vary, and the loads of interest vary between drivetrain designs. A systematic method to evaluate the capability of a test bench to impose the loads of interest has been developed. This method can be applied to any test bench and drivetrain design. Part I of this paper presents the methodology and recommendations for presenting and interpreting the results. The demonstration of the method is the focus of part II. Overall, this two-part paper aims to establish guidelines for consideration by the IEA task force 35 for ground based testing for wind turbines and their components.
A Comparative Assessment on Static and Dynamic PCA for Fault Detection in Natural Gas Transmission Systems
Authors: Pinzón Horacio , Audivet Cinthia , Torres Melitsa , Alexander Javier , Sanjuán Marco
Published: August 2017

Sustainability of natural gas transmission infrastructure is highly related to the system’s ability to decrease emissions due to ruptures or leaks. Although traditionally such detection relies in alarm management system and operator’s expertise, given the system’s nature as large-scale, complex, and with vast amount of information available, such alarm generation is better suited for a fault detection system based on data-driven techniques. This would allow operators and engineers to have a better framework to address the online data being gathered.

This paper presents an assessment on multiple fault-case scenarios in critical infrastructure using two different data-driven based fault detection algorithms: Principal component analysis (PCA) and its dynamic variation (DPCA).

Both strategies are assessed under fault scenarios related to natural gas transmission systems including pipeline leakage due to structural failure and flow interruption due to emergency valve shut down. Performance evaluation of fault detection algorithms is carried out based on false alarm rate, detection time and misdetection rate. The development of modern alarm management frameworks would have a significant contribution in natural gas transmission systems’ safety, reliability and sustainability.
Estimating Residential Wall Thermal Resistance From Exterior Thermal Imaging
Authors: Alshatshati Salahaldin , Hallinan Kevin P. , Alrobaian Abdulrahman , Naji Adel , Altarhuni Badr
Published: August 2017

Building energy audits are both expensive, on the order of $0.50(US)/sf [1], and there aren’t enough auditors to survey the entire building stock in the U.S. Needed are lower cost automated approaches for rapidly evaluating the energy effectiveness of buildings. A key element of such an approach would be automated measurements of envelope R-values. Proposed is the use of single point-in-time thermal images potentially obtainable from drive-by thermal imaging to infer wall and window R-values. A data mining based approach is proposed, which seeks to calibrate the measured exterior wall temperatures to known and measured R-values for a small subset of residences. In this approach, visual imagery is first used to determine the wall emissivity based on the color of the wall siding in order to yield an estimate of the wall temperature. A Random Forest model is developed using the training set comprised of the residences with known R-value. This model can then be used to estimate R- and C-values of other houses based upon their measured exterior temperatures. The results show that the proposed approach is capable of accurately estimating envelope thermal characteristics over a spectrum of envelope R-values and thermal capacitances present in residences nationally. The resulting error for the houses considered is maximally 12% using as few as nine training houses. The data mining approach has significantly greater accuracy than modeling-based approaches in the literature.
Installed Capacity Price Competitiveness of CSP Versus PV
Authors: McBride Troy , Stettenheim Joel
Published: August 2017

Solar electricity can be generated by either photovoltaic panels or concentrating solar power (CSP), which uses a thermal cycle. The recent historic drop in photovoltaic panel prices has encouraged the opinion that CSP, with its higher levelized cost of energy, has poor prospects outside of niche deployments. We review evidence for the contrary view, supported by the International Energy Agency and others, that CSP’s market prospects are in fact bright.
Transient Analysis of Simultaneous Multivariable Signals on Fuel Cell/Gas Turbine Hybrid to Define Control Strategies for Cathode Parameters and Compressor Stall
Authors: Restrepo Bernardo , Tucker David
Published: August 2017

Transients in a hybrid system composed of a solid oxide fuel cell (SOFC) and a gas turbine (GT) were evaluated during simultaneous manipulation of system airflow bypasses and turbine electric load. The three airflow bypass valves selected for study were chosen for their potential application in controlling dynamic excursions of the main fuel cell and gas turbine parameters in the system. The objective of this work was to understand the physical behavior by the simultaneous operation of the bypass valves along with the turbine electric load in order to formulate scenarios of control on the key parameters relevant to system failure, specifically from compressor stall and surge. Empirical data was collected using the National Energy Technology Laboratory Hybrid Performance project hardware simulation of a SOFC/GT hybrid. Step changes were implemented in all three valves for various open/close valve commands and increase/decrease of the turbine electric load simultaneously. The transient response of process variables was analyzed to determine the potential for mitigating or aggravating compressor stall and surge during load excursions.
Minimization of Stack Mass in Miniature PEM Fuel Cell Systems With DC/DC Converters
Authors: Wei Yijin , McKahn Denise A.
Published: August 2017

Polymer electrolyte membrane (PEM) fuel cells have been explored as a clean battery replacement in portable and miniature applications where total system mass and specific energy density (Wh/kg) are critical design constraints. By coupling a boost (step-up) DC/DC converter with a miniature PEM fuel cell stack, the total power system mass can be reduced while providing voltage regulation capabilities not available with a fuel cell alone. This configuration is applied to the design of a controlled meteorological (CMET) balloon power system as a case-study. In this work, we designed and tested three different micro-power DC/DC boost converters that were deployed in series with a PEM fuel cell stack. Testing of the converters revealed a transition region in which the converter output voltage is hysteretic, not well regulated, and dependent on the input voltage. As a result, it is important to identify the minimal stable and reliable input voltage to a given DC/DC converter in order to minimize the fuel cell power system mass. An optimization strategy is presented here that enables the minimization of PEM fuel cell stack mass by identifying the appropriate DC/DC converter input voltage subject to the dimension constraints of the fuel cell components. Prototype DC/DC converters were then experimentally tested in direct connection to a miniature two-cell PEM fuel cell stack.
Genome Sequences of Seven Foot-and-Mouth Disease Virus Isolates Collected from Serial Samples from One Persistently Infected Carrier Cow in Vietnam
Authors: Pauszek Steven J. , Bertram Miranda R. , Vu Le T. , Hartwig Ethan J. , Smoliga George R. , Brito Barbara , Stenfeldt Carolina , VanderWaal Kimberley , Fish Ian H. , Hung Vo V. , Phuong Nguyen T. , Hoang Bui H. , Rodriguez Luis L. , Dung Do H. , Arzt Jonathan
Published: August 2017

Several foot-and-mouth disease virus (FMDV) carrier cattle were identified in Vietnam by the recovery of infectious virus from oropharyngeal fluid. This report contains the first near-complete genome sequences of seven viruses from sequential samples from one carrier animal collected over the course of 1 year. The characterization of within-host viral evolution has implications for FMDV control strategies.
Whole-Genome Sequences of Salmonella enterica subsp.
enterica
Serovar Typhimurium Strains TT6675 and TT9097 Employed in the Isolation and Characterization of a Giant Phage Mutant Collection
Authors: Gan Han Ming , Eng Wilhelm Wei Han , Barton Melissa K. , Adams Lily E. , Samsudin Nurul Aisyah , Bartl Austin J. , Hudson André O. , Savka Michael A. , Thomas Julie A.
Published: August 2017

We report here the genome sequences of
Salmonella enterica
subsp.
enterica
serovar Typhimurium strains TT6675 and TT9097, which we utilize for genetic analyses of giant bacterial viruses. Our analyses identified several genetic variations between the two strains, most significantly confirming strain TT6675 as a serine suppressor and TT9097 as a nonsuppressor.
Draft Genome Sequence of Strain R_RK_3, an Iron-Depositing Isolate of the Genus
Rhodomicrobium
, Isolated from a Dewatering Well of an Opencast Mine
Authors: Braun Burga , Künzel Sven , Schröder Josephin , Szewzyk Ulrich
Published: August 2017

Rhodomicrobium
sp. strain R_RK_3 is an iron-depositing bacterium from which we report the draft genome. This strain was isolated from ochrous depositions of a mining well pump in Germany. The Illumina NextSeq technique was used to sequence the genome of the strain.
Taxonomic Resolution of the Nematophagous Fungal Isolate ARF18 via Genome Sequencing
Authors: Sharma Sandeep , Zaccaron Alex Z. , Ridenour John B. , Bradshaw Amy , Kirkpatrick Terry L. , Cartwright Kelly , Bluhm Burton H.
Published: August 2017

The taxonomically uncharacterized nematophagous fungus ARF18, which parasitizes cysts, juveniles, and adults of the soybean cyst nematode (
Heterodera glycines
), was proposed as a nematode biological control agent in 1991. A 46.3-Mb draft genome sequence of this fungus is presented, and a tentative taxonomic identification as a novel species of
Brachyphoris
is proposed.
Microbiota, Liver Diseases, and Alcohol
Authors: Cassard Anne-Marie , Gérard Philippe , Perlemuter Gabriel
Published: August 2017

Being overweight and obesity are the leading causes of liver disease in Western countries. Liver damage induced by being overweight can range from steatosis, harmless in its simple form, to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Alcohol consumption is an additional major cause of liver disease. Not all individuals who are overweight or excessively consume alcohol develop nonalcoholic fatty liver diseases (NAFLD) or alcoholic liver disease (ALD) and advanced liver disease. The role of the intestinal microbiota (IM) in the susceptibility to liver disease in this context has been the subject of recent studies. ALD and NAFLD appear to be influenced by the composition of the IM, and dysbiosis is associated with ALD and NAFLD in rodent models and human patient cohorts. Several microbial metabolites, such as short-chain fatty acids and bile acids, are specifically associated with dysbiosis. Recent studies have highlighted the causal role of the IM in the development of liver diseases, and the use of probiotics or prebiotics improves some parameters associated with liver disease. Several studies have made progress in deciphering the mechanisms associated with the modulation of the IM. These data have demonstrated the intimate relationship between the IM and metabolic liver disease, suggesting that targeting the gut microbiota could be a new preventive or therapeutic strategy for these diseases.
The Potential of Probiotics as a Therapy for Osteoporosis
Authors: Collins Fraser L. , Rios-Arce Naiomy D. , Schepper Jonathan D. , Parameswaran Narayanan , McCabe Laura R.
Published: August 2017

Osteoporosis, characterized by low bone mass and micro-architectural deterioration of bone tissue with increased risk of fracture, can be categorized into two forms: primary and secondary, depending on whether it occurs as part of the natural aging process (estrogen deficiency) or as part of disease pathology. In both forms bone loss is due to an imbalance in the bone remodeling process, with resorption/formation skewed more toward bone loss. Recent studies and emerging evidence consistently demonstrate the potential of the intestinal microbiota to modulate bone health. This review discusses the process of bone remodeling and the pathology of osteoporosis and introduces the intestinal microbiota and its potential to influence bone health. In particular, we highlight recent murine studies that examine how probiotic supplementation can both increase bone density in healthy individuals and protect against primary (estrogen deficiency) as well as secondary osteoporosis. Potential mechanisms are described to account for how probiotic treatments could be exerting their beneficial effect on bone health.
Protocol for a pilot randomised controlled trial of metformin in pre-diabetes after kidney transplantation: the Transplantation and Diabetes (Transdiab) study
Authors: Alnasrallah Basil , Pilmore Helen , Manley Paul
Published: August 2017

Introduction

Post-transplant diabetes mellitus (PTDM) is a common complication of kidney transplantation and is associated with significant morbidity and mortality. In the general population, metformin has been used for diabetes prevention in high-risk individuals. Improving insulin sensitivity is one of many proven favourable effects of metformin. Despite the high incidence of PTDM in kidney transplant recipients, there is a lack of evidence for the role of metformin in the prevention of diabetes in this setting.

Methods and analysis

Transplantation andDiabetes (Transdiab)is a single-centre, unblinded, pilot randomised controlled trial assessing the feasibility, tolerability and efficacy of metformin after renal transplantation in patients with impaired glucose tolerance (IGT). Participants will undergo an oral glucose tolerance test in the 4–12 weeks post-transplantation; those with IGT will be randomised to standard care or standard care and metformin 500 mg twice daily, and followed up for 12 months. The primary outcomes of the study will be the feasibility of recruitment, the tolerability of metformin assessed using the Gastrointestinal Symptom Rating Scale at 3 and 12 months, and the efficacy of metformin assessed by morning glucose and glycated haemoglobin at 3, 6, 9 and 12 months.

Ethics and dissemination

Despite the significant morbidity and mortality of PTDM, there are currently no randomised clinical trials assessing pharmacological interventions for its prevention after kidney transplantation. The Transdiab trial will thus provide important data on the feasibility, safety, tolerability and efficacy of metformin after renal transplantation in patients with IGT; this will facilitate undertaking larger multicentre trials of interventions to reduce the incidence or severity of diabetes after kidney transplantation. This study has been approved by the Northern B Health and Disability Ethics Committee of the Ministry of Health in New Zealand. On study completion, results are expected to be published in a peer-reviewed journal.

Trial registration number

Australian New Zealand Clinical Trials Registry Number: ACTRN12614001171606.
The association between vertebrobasilar insufficiency and the risk of dementia: a nationwide register-based retrospective cohort study in Taiwan
Authors: Yang Fu-Chi , Chen Shao-Yuan , Yin Jiu-Haw , Lin Chun-Chieh , Sung Yueh-Feng , Chou Chung-Hsing , Chung Chi-Hsiang , Chien Wu-Chien , Tsai Chia-Kuang , Tsai Chia-Lin , Lin Guan-Yu , Lee Jiunn-Tay
Published: August 2017

Objectives

Neurodegenerative disorders are reportedly characterised by decreased regional cerebral blood flow. However, the association between vertebrobasilar insufficiency (VBI) and dementia remains unclear. In this nationwide, population-based, retrospective cohort study, we explored the potential association between VBI and dementia.

Design

Nationwide population-based cohort study.

Setting

Patients with VBI were newly diagnosed between 2000 and 2005 from the Taiwan National Health Insurance Research Database.

Participants

We included 3642 subjects as the VBI group. The control cohort included 14 568 randomly selected age-matched and sex-matched VBI-free individuals.

Outcome measures

All subjects were followed until the diagnosis of dementia, death or the end of 2010. Patients with VBI, dementia (viz, vascular and non-vascular, including Alzheimer’s) subtypes and other confounding factors were identified according to the International Classification of Diseases Clinical Modification Codes. Cox proportional hazards regression analysis was employed to examine adjusted HRs after adjusting for confounding factors.

Results

Patients with VBI had a 1.807-fold (95% CI 1.643 to 1.988, p<0.001) higher risk to develop all-cause dementia than individuals without VBI. The risk was significantly higher in the VBI group than in the non-VBI group regardless of age (<65 years: HR: 2.997, 95% CI 1.451 to 6.454, p<0.001; ≥65 years: HR: 1.752, 95% CI 1.584 to 1.937, p<0.001). The VBI group had a higher risk of all-cause dementia than the non-VBI group regardless of sex and follow-up time intervals (<1 year, 1–2 years and≥2 years).

Conclusion

Patients with VBI appear to have an increased risk of developing dementia. Further research is needed to investigate the underlying pathophysiology.
End-of-life prescribing of aspirin in patients with breast or colorectal cancer
Authors: Murphy Laura , Brown Chris , Smith Amelia , Cranfield Faith , Sharp Linda , Visvanathan Kala , Bennett Kathleen , Barron Thomas Ian
Published: August 2017

Objectives

The aim of this study was to evaluate the influence of an approaching cancer death on end-of-life aspirin use, a frequently prescribed medication for cardiovascular disease prevention.

Methods

This study was conducted using linked cancer registry and prescribing data. Breast (n=1151) and colorectal (n=1859) cancer decedents were matched to cancer survivors and the probability of either initiating aspirin, or continuing established aspirin use, was estimated in consecutive periods over the 5 years approaching a cancer-specific death (decedents) or matched index date (survivors).

Results

Using the linked data sets, we identified patients who died of their cancer (decedents) between 1 January 2001 and 31 December 2009. In the 5 years prior to death, we compared (1) the probability of initiating aspirin use for the first time, and (2) the probability of continuing aspirin use. In comparison to matched cancer survivors, an approaching cancer death was not associated with a reduction in aspirin initiation by breast or colorectal cancer decedents. However, the probability of continuing established aspirin use declined considerably in the 24 months approaching death and at the time of a death was significantly lower for breast (risk difference (RD) −0.26, 95% CI −0.33 to −0.20) and colorectal (RD −0.38, 95% CI −0.46 to −0.30) cancer decedents versus matched survivors.

Conclusion

A significant proportion of patients discontinue their aspirin in the time approaching a breast or colorectal cancer-specific death. The safety and benefits of this are unclear and empirical data are needed to guide decisions about aspirin use in the end of life.
Carotid endarterectomy for treatment of carotid in-stent restenosis: long-term follow-up results and surgery experiences from one single centre
Authors: Yu Le-Bao , Yan Wei , Zhang Qian , Zhao Ji-Zong , Zhang Yan , Wang Rong , Shao Jun-Shi , Zhang Dong
Published: August 2017

Objective

Few studies have reported the surgical treatment of carotid in-stent restenosis (ISR), more data and longer follow-up are needed. We describe the surgical treatment of ISR by standard carotid endarterectomy (CEA) with stent removal, including long-term follow-up in 10 patients from our centre.

Methods

Ten patients from our centre who underwent CEA with stent removal for ISR were retrospectively analysed, including nine symptomatic and one asymptomatic ISR of at least 70% with mean age 67.3, the median time between carotid artery stenting and CEA was 17 months (range, 2–54 months).

Results

Standard CEA with stent removal was performed in all 10 patients without much technical difficulty (9 male and 1 female, mean age 67.3). Two cases were performed in hybrid operation room. There were a total of three complications that happened in three patients (30%) respectively. An asymptomatic dissecting aneurysm was formed on the petrous internal carotid artery in one patient who was followed up without intervention. In the second case, dissection occurred in the arterial wall distal to the site of the stent after stent removal revealed by intraoperative angiography, and another stent was implanted. The patient sustained temporary hypoglossal nerve dysfunction postoperatively. The third patient suffered cerebral hyperperfusion with complete recovery when discharged. No neurological complications occurred in other seven patients. After follow-up of 25 months (range, 11–54 months), one patient died of rectal cancer without ischaemic attack and restenosis 4 years postoperation; in one patient occurred recurrent symptomatic restenosis (90%) 1 year later; all other patients remained asymptomatic and without recurrent restenosis (>50%) by follow-up carotid ultrasound or CT angiography.

Conclusion

It seems that CEA with stent removal is a reasonable choice, by experienced hand, for symptomatic ISR with higher but acceptable complications. The indication of stent removal for asymptomatic ISR needs further observation.
Rhizosphere effect is stronger than PAH concentration on shaping spatial bacterial assemblages along centimetre-scale depth gradients
Authors: Bourceret Amélia , Leyval Corinne , Thomas François , Cébron Aurélie
Published: August 2017

At centimetre scale, soil bacterial assemblages are shaped by both abiotic (edaphic characteristics and pollutants) and biotic parameters. In a rhizobox experiment carried out on planted industrial soil contaminated with polycyclic aromatic hydrocarbons (PAHs), we previously showed that pollution was distributed randomly with hot and cold spots. Therefore, in the present study, we investigated the effect of this patchy PAH distribution on the bacterial community assemblage and compared it with that of root depth gradients found in the rhizosphere of either alfalfa or ryegrass. Sequencing of 16S rRNA amplicons revealed a higher bacterial diversity in ryegrass rhizosphere and enrichment in specific taxa by the 2 plant species. Indeed, Bacteroidetes, Firmicutes, and Gammaproteobacteria were globally favored in alfalfa, whereas Acidimicrobiia, Chloroflexi, Alpha-, and Betaproteobacteria were globally favored in ryegrass rhizosphere. The presence of alfalfa created depth gradients of root biomass, carbohydrate, and pH, and actually shaped the bacterial assemblage, favoring Actinobacteria near the surface and Gemmatimonadetes and Proteobacteria at greater depths. Contrarily, the bacterial assemblage was homogeneous all along depths of the ryegrass root system. With both plant species, the PAH content and random distribution had no significant effect on bacterial assemblage. Globally, at centimeter scale, bacterial community assemblages were mostly shaped by soil physical and chemical depth gradients induced by root growth but not by patchy PAH content.
Automatic generation of essentially distinct Hugenholtz diagrams
Authors: Tag M. A. , Khène S.
Published: August 2017

A new automatic C/C++ program which generates all linked and essentially distinct vacuum Hugenholtz-type diagrams of many-body perturbation series up to arbitrary order is presented. The output results are shown as lists of integers which present the sites of suitable vertex of each diagram with its symmetry factor. The analysis results up to 10-order are displayed.
Incremental Learning-Based Facial Expression Classification System Using a Novel Multinomial Classifier
Authors: Sultan Zia M. , Hussain Majid , Arfan Jaffar M.
Published: August 2017

Facial expressions recognition is a crucial task in pattern recognition and it becomes even crucial when cross-cultural emotions are encountered. Various studies in the past have shown that all the facial expressions are not innate and universal, but many of them are learned and culture-dependent. Extreme facial expression recognition methods employ different datasets for training and later use it for testing and demostrate high accuracy in recognition. Their performances degrade drastically when expression images are taken from different cultures. Moreover, there are many existing facial expression patterns which cannot be generated and used as training data in single training session. A facial expression recognition system can maintain its high accuracy and robustness globally and for a longer period if the system possesses the ability to learn incrementally. We also propose a novel classification algorithm for multinomial classification problems. It is an efficient classifier and can be a good choice for base classifier in real-time applications. We propose a facial expression recognition system that can learn incrementally. We use Local Binary Pattern (LBP) features to represent the expression space. The performance of the system is tested on static images from six different databases containing expressions from various cultures. The experiments using the incremental learning classification demonstrate promising results.
A Hamilton–Jacobi approach to characterize the evolutionary equilibria in heterogeneous environments
Authors: Mirrahimi Sepideh
Published: August 2017

In this work, we characterize the solution of a system of elliptic integro-differential equations describing a phenotypically structured population subject to mutation, selection and migration between two habitats. Assuming that the effects of the mutations are small but nonzero, we show that the population’s phenotypical distribution has at most two peaks and we give explicit conditions under which the population will be monomorphic (unimodal distribution) or dimorphic (bimodal distribution). More importantly, we provide a general method to determine the dominant terms of the population’s distribution in each case. Our work, which is based on Hamilton–Jacobi equations with constraint, goes further than previous works where such tools were used, for different problems from evolutionary biology, to identify the asymptotic solutions, while the mutations vanish, as a sum of Dirac masses. The main elements for the computation of the dominant terms of the population’s distribution are the convergence of the logarithmic transform of the solution to the unique solution of a Hamilton–Jacobi equation and the computation of the correctors. This method allows indeed to go further than the Gaussian approximation commonly used by biologists and makes a connection between the theories of adaptive dynamics and quantitative genetics. Our work being motivated by biological questions, the objective of this paper is to provide the mathematical details which are necessary for our biological results [S. Mirrahimi and S. Gandon, The equilibrium between selection, mutation and migration in spatially heterogeneous environments, in preparation].
A Korn-type inequality in SBD for functions with small jump sets
Authors: Friedrich Manuel
Published: August 2017

We present a Korn-type inequality in a planar setting for special functions of bounded deformation. We prove that for each function in [Formula: see text] with a sufficiently small jump set the distance of the function and its derivative from an infinitesimal rigid motion can be controlled in terms of the linearized elastic strain outside of a small exceptional set of finite perimeter. Particularly, the result shows that each function in [Formula: see text] has bounded variation away from an arbitrarily small part of the domain.
The Cahn–Hilliard–Oono equation with singular potential
Authors: Giorgini Andrea , Grasselli Maurizio , Miranville Alain
Published: August 2017

We consider the so-called Cahn–Hilliard–Oono equation with singular (e.g. logarithmic) potential in a bounded domain of [Formula: see text], [Formula: see text]. The equation is subject to an initial condition and Neumann homogeneous boundary conditions for the order parameter as well as for the chemical potential. However, contrary to the Cahn–Hilliard equation, the total mass might not be conserved. The existence of a global finite energy solution to such a problem was proven by Miranville and Temam. We first establish some regularization properties in finite time of the (unique) solution. Then, in dimension two, we prove the so-called strict separation property, namely, we show that any finite energy solution stays away from pure phases, uniformly with respect to the initial energy and the total mass. Taking advantage of these results, we study the long-time behavior of solutions. More precisely, we establish the existence of the global attractor in both two and three dimensions. Due to the strict separation property in dimension two, we also prove the existence of exponential attractors and we show that a finite energy solution always converges to a single equilibrium even though the mass is not conserved.
Regularity and approximation of strong solutions to rate-independent systems
Authors: Rindler Filip , Schwarzacher Sebastian , Süli Endre
Published: August 2017

Rate-independent systems arise in a number of applications. Usually, weak solutions to such problems with potentially very low regularity are considered, requiring mathematical techniques capable of handling nonsmooth functions. In this work, we prove the existence of Hölder-regular strong solutions for a class of rate-independent systems. We also establish additional higher regularity results that guarantee the uniqueness of strong solutions. The proof proceeds via a time-discrete Rothe approximation and careful elliptic regularity estimates depending in a quantitative way on the (local) convexity of the potential featuring in the model. In the second part of the paper, we show that our strong solutions may be approximated by a fully discrete numerical scheme based on a spatial finite element discretization, whose rate of convergence is consistent with the regularity of strong solutions whose existence and uniqueness are established.
A Tool for xMAS-Based Modeling and Analysis of Communication Fabrics in Simulink
Authors: Zhao Xueqian , Lu Zhonghai
Published: August 2017

The eXecutable Micro-Architectural Specification (xMAS) language developed in recent years finds an effective way to model on-chip communication fabrics and enables performance-bound analysis with network calculus at the micro-architectural level. For network-on-Chip (NoC) performance analysis, model validation is essential to ensure correctness and accuracy. In order to facilitate the xMAS modeling and corresponding analysis validation, this work presents a unified platform based on xMAS in Simulink. The platform provides a friendly graphical user interface for xMAS modeling and parameter setup by taking advantages of the Simulink modeling environment. The
regulator
and
latency-rate sever
are added to the xMAS primitive set to support typical flow and service behaviors. Hierarchical model build-up and Verilog-HDL code generation are essentially supported to manage complex models and to conduct cycle-accurate bit-accurate simulations. Based on the generated simulation models of xMAS, this tool is applied to evaluate the tightness of analytical delay bound results. We demonstrate the application as well as the work flow of the xMAS tool through a two-agent communication example and an all-to-one communication example with a tree topology.
Analysis of JavaScript Programs
Authors: Sun Kwangwon , Ryu Sukyoung
Published: August 2017

JavaScript has been a
de facto
standard language for client-side web programs, and now it is expanding its territory to general purpose programs. In this article, we classify the client-side JavaScript research for the last decade or so into six topics: static analysis, dynamic analysis, formalization and reasoning, type safety and JIT optimization, security for web applications, and empirical studies. Because the majority of the research has focused on static and dynamic analyses of JavaScript, we evaluate research trends in the analysis of JavaScript first and then the other topics. Finally, we discuss possible future research directions with open challenges.