bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional Intervention as an Essential Part of Multiple Sclerosis Treatment?
Authors: PENESOVÁ A. , DEAN Z. , KOLLÁR B. , HAVRANOVÁ A. , IMRICH R. , VLČEK M. , RÁDIKOVÁ Ž.
Published: July 2019

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system. In addition to the genetic, epigenetic and immunological components, various other factors, e.g. unhealthy dietary habits, play a role in the MS pathogenesis. Dietary intervention is a highly appealing approach, as it presents a simple and relatively low risk method to potentially improve outcomes in patients with brain disorders in order to achieve remission and improvement of clinical status, well-being and life expectancy of patients with MS. The importance of saturated fat intake restriction for the clinical status improvement of MS patients was pointed for the first time in 1950s. Recently, decreased risk of first clinical diagnosis of CNS demyelination associated with higher intake of omega-3 polyunsaturated fatty acids particularly originating from fish was reported. Only few clinical trials have been performed to address the question of the role of dietary intervention, such is e.g. low saturated fat diet in MS treatment. This review summarizes current knowledge about the effect of different dietary approaches (diets low in saturated fat and dietary supplements such as fish oil, lipoic acid, omega-3 polyunsaturated fatty acids, seeds oils, high fiber diet, vitamin D, etc.) on neurological signs, patient’s well-being, physical and inflammatory status. So far the results are not conclusive, therefore much more research is needed to confirm and to understand the effectiveness of these dietary interventions in the long term and well defined studies.
Respiratory-Induced Hemodynamic Changes Measured by Whole-Body Multichannel Impedance Plethysmography
Authors: LANGER P. , JURÁK P. , VONDRA V. , HALÁMEK J. , MEŠŤANÍK M. , TONHAJZEROVÁ I. , VIŠČOR I. , SOUKUP L. , MATEJKOVA M. , ZÁVODNÁ E. , LEINVEBER P.
Published: July 2019

The cardiovascular system is described by parameters including blood flow, blood distribution, blood pressure, heart rate and pulse wave velocity. Dynamic changes and mutual interactions of these parameters are important for understanding the physiological mechanisms in the cardiovascular system. The main objective of this study is to introduce a new technique based on parallel continuous bioimpedance measurements on different parts of the body along with continuous blood pressure, ECG and heart sound measurement during deep and spontaneous breathing to describe interactions of cardiovascular parameters. Our analysis of 30 healthy young adults shows surprisingly strong deep-breathing linkage of blood distribution in the legs, arms, neck and thorax. We also show that pulse wave velocity is affected by deep breathing differently in the abdominal aorta and extremities. Spontaneous breathing does not induce significant changes in cardiovascular parameters.
Ulinastatin Alleviates Neurological Deficiencies Evoked by Transient Cerebral Ischemia via Improving Autophagy, Nrf-2-ARE and Apoptosis Signals in Hippocampus
Authors: JIANG X.-M. , HU J.-H. , WANG L.-L. , MA C. , WANG X. , LIU X.-L.
Published: July 2019

Ulinastatin [or called as urinary trypsin inhibitor (UTI)] plays a role in regulating neurological deficits evoked by transient cerebral ischemia. However, the underlying mechanisms still need to be determined. The present study was to examine the effects of UTI on autophagy, Nrf2-ARE and apoptosis signal pathway in the hippocampus in the process of neurological functions after cerebral ischemia using a rat model of cardiac arrest (CA). CA was induced by asphyxia followed by cardiopulmonary resuscitation (CPR) in rats. Western blot analysis was employed to determine the expression of representative autophagy (namely, Atg5, LC3, Beclin 1), p62 protein (a maker of autophagic flux), and Nrf2-ARE pathways. Neuronal apoptosis was assessed by determining expression levels of Caspase-3 and Caspase-9, and by examining terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL). The modified neurological severity score (mNSS) and spatial working memory performance were used to assess neurological deficiencies in CA rats. Our results show that CA amplified autophagy and apoptotic Caspase-3/Caspase-9, and downregulated Nrf2-ARE pathway in the hippocampus CA1 region. Systemic administration of UTI attenuated autophagy and apoptosis, and largely restored Nrf2-ARE signal pathway following cerebral ischemia and thereby alleviated neurological deficits with increasing survival of CA rats. Our data suggest that UTI improves the worsened protein expression of autophagy and apoptosis, and restores Nrf2-ARE signals in the hippocampus and this is linked to inhibition of neurological deficiencies in transient cerebral ischemia. UTI plays a beneficial role in modulating neurological deficits induced by transient cerebral ischemia via central autophagy, apoptosis and Nrf2-ARE mechanisms.
Pathophysiological Characteristics of Non-Alcoholic Steatohepatitis-Like Changes in Cholesterol-Loaded Type 2 Diabetic Rats
Authors: TORINIWA Y. , MURAMATSU M. , ISHII Y. , RIYA E. , MIYAJIMA K. , OHSHIDA S. , KITATANI K. , TAKEKOSHI S. , MATSUI T. , KUME S. , YAMADA T. , OHTA T.
Published: July 2019

Spontaneously Diabetic Torii (SDT) fatty rats, a new obese diabetic model, reportedly presented with features of non-alcoholic steatohepatitis (NASH) after 32 weeks of age. We tried to accelerate the onset of NASH in SDT fatty rats using dietary cholesterol loading and noticed changes in the blood choline level which is expected to be a NASH biomarker. Body weight and biochemical parameters were measured from 8 to 24 weeks of age. At 16, 20, 24 weeks, pathophysiological analysis of the livers were performed. Hepatic lipids, lipid peroxides, and the expression of mRNA related to triglyceride (TG) synthesis, inflammation, and fibrosis were evaluated at 24 weeks. Hepatic fibrosis was observed in SDT fatty rats fed cholesterol-enriched diets (SDT fatty-Cho) from 16 weeks. Furthermore, hepatic lipids and lipid peroxide were significantly higher in SDT fatty-Cho than SDT fatty rats fed normal diets at 24 weeks. Hepatic mRNA expression related to TG secretion decreased in SDT fatty-Cho, and the mRNA expression related to inflammation and fibrosis increased in SDT fatty-Cho at 24 weeks. Furthermore, SDT fatty-Cho presented with increased plasma choline, similar to human NASH. There were no significant changes in the effects of feeding a cholesterol-enriched diet in Sprague-Dawley rats. SDT fatty-Cho has the potential to become a valuable animal model for NASH associated with type 2 diabetes and obesity.
Occurrence of Serum Antibodies Against Wheat Alpha-Amylase Inhibitor 0.19 in Celiac Disease
Authors: SÁNCHEZ D. , ŠTĚPÁNOVÁ HONZOVÁ S. , HOSPODKOVÁ M. , HOFFMANOVÁ I. , HÁBOVÁ V. , HALADA P. , TLASKALOVÁ-HOGENOVÁ H. , TUČKOVÁ L.
Published: July 2019

The alcohol-soluble fraction of wheat gluten (gliadins) induces in genetically susceptible individuals immunologically mediated celiac disease (CLD). However, gliadins and related cereal proteins are not unique foodstuff targets of CLD patients´ immune system. Non-gluten wheat alpha-amylase inhibitor 0.19 (AAI 0.19) has been found to be capable of activating human monocyte-derived dendritic cells and inducing pro-inflammatory status in intestinal mucosa of patients with celiac disease (CLD). The possible contribution of this reactivity in incomplete remission of CLD patients on a gluten-free diet (GFD) is matter of contention. In an attempt to characterize the antigenicity of AAI 0.19 in patients with active CLD, patients on a GFD and healthy controls we developed ELISA employing wheat recombinant AAI 0.19. Using this test we revealed a significant (P<0.001) elevation of IgA anti-AAI 0.19 antibodies (Ab) in patients with active CLD (12 out of 30 patients were seropositive) but also in CLD patients on a GFD (15/46), in contrast to healthy controls (2/59). Anti-AAI 0.19 IgG Ab levels were increased (P<0.001) only in patients with active CLD (14/30) in contrast to the controls. Interestingly, the levels of anti-AAI 0.19 IgG Ab were decreased in CLD patients on a GFD (P<0.001, 1/46) compared to the controls (1/59). Notably, 20 out of 30 patients with active CLD were positive either for IgA or for IgG anti-AAI 0.19 Ab. Thus, the majority of CLD patients developed a robust IgA and IgG Ab response against AAI 0.19. These findings may contribute to the broadening of the knowledge about CLD pathogenesis.
Gender-based Differences in Language Learning Strategies Among Undergraduates in a Malaysian Public University
Authors: Ho Ai Ping , Ng Lee Luan
Published: July 2019

Unemployment among the Malaysian public universities’ graduates due to their inability to communicate proficiently and accurately in English language with proper pronunciation has been a concern among various parties. One possible method to address such issue is to look at how these graduates learn and improve their command of English language. Language learning strategies (LLS) is one of the prominent variables that can affect their language learning process. With that in view, this study investigated the LLSs used by the first year undergraduates in a Malaysian public university. It also examined the relationship between language learning strategies based on gender. The survey utilised the Strategy Inventory for Language Learning (SILL) by Oxford (1990) on 535 male and 1173 female respondents. Data obtained were analysed using descriptive statistics, t-test, One-way ANOVA and chi-square test. Finding revealed that females employed more strategies if compared to males. The research result also showed that metacognitive strategies were highly employed by these undergraduates whereas affective strategies were least used among them. Further ANOVA test revealed there was a significant difference between the language learning strategies used by these undergraduates. The implications of these findings to educators, scholars and researchers were also discussed.
Typifying and Characterizing Suicide and its Dynamics of Progression towards Completion: A Model
Authors: Anand Gautam
Published: July 2019

Suicide has its own trends and path. An emotional set back may leads to suicide is seemed to happen instantly but it is not true, it takes times to complete .All most all of us have to experience death wishes but never reach to that point when said completed. Very few will reach to that point where assessed. This study has aim to decide the path by which completion occurs. Study has used the various discrete data of various studies freely available on internet. They were analyzed and arranged logically in sequence to set the path and trends. Conclusion: Everyone in their life at least has to wish to die but very few complete it. It progress in certain path as wish further strengthen by idea following celebrate self-harm may repeat or accidentally completed if not further proceeded to take attempt. It may be completed or rest as further are risk of suicide.
Motivations for Industry Stakeholders in China, Vietnam, Thailand and Malaysia to Improve Livestock Welfare
Authors: Sinclair Michelle , Idrus Zulkifli , Nhiem Duong van , Katawatin Suporn , Todd Brendon , Burns Georgette Leah , Phillips Clive J. C.
Published: July 2019

Understanding what might motivate livestock stakeholders to improve animal welfare is useful information when developing initiatives that benefit from stakeholder engagement. This study was designed to assess the strength of motivating drivers in the development of attitudes to animal welfare, and the factors that impacted their ability to improve animal welfare. During a series of qualitative focus group sessions with livestock leaders across the same countries (Malaysia, China, Vietnam and Thailand), the current study presented livestock leaders (n = 139) with the most significant results in their country, and collected data pertaining to the meaning and applicability of these results. This data was then subject to thematic analysis to identify salient and repeated motivating factors and meanings. This process revealed a complex picture of relationships between motivators and the contexts that drive them. Figures are presented to begin illustrating these relationships. Some strong motivators were uncovered that were previously rated low in the survey (i.e., financial benefit) or not included at all (e.g., food safety). This paper also presents the opportunity to better understand the strength and relationship of extrinsic and intrinsic motivational forces behind animal welfare improvement.
Ectopic or Over-Expression of Class 1 Phytoglobin Genes Confers Flooding Tolerance to the Root Nodules of Lotus japonicus by Scavenging Nitric Oxide
Authors: Fukudome Mitsutaka , Watanabe Eri , Osuki Ken-ichi , Uchi Nahoko , Uchiumi Toshiki
Published: July 2019

Flooding limits biomass production in agriculture. Leguminous plants, important agricultural crops, use atmospheric dinitrogen gas as nitrogen nutrition by symbiotic nitrogen fixation with rhizobia, but this root-nodule symbiosis is sometimes broken down by flooding of the root system. In this study, we analyzed the effect of flooding on the symbiotic system of transgenic Lotus japonicus lines which overexpressed class 1 phytoglobin (Glb1) of L. japonicus (LjGlb1-1) or ectopically expressed that of Alnus firma (AfGlb1). In the roots of wild-type plants, flooding increased nitric oxide (NO) level and expression of senescence-related genes and decreased nitrogenase activity; in the roots of transgenic lines, these effects were absent or less pronounced. The decrease of chlorophyll content in leaves and the increase of reactive oxygen species (ROS) in roots and leaves caused by flooding were also suppressed in these lines. These results suggest that increased levels of Glb1 help maintain nodule symbiosis under flooding by scavenging NO and controlling ROS.
Ciliopathy-Associated Protein Kinase ICK Requires Its Non-Catalytic Carboxyl-Terminal Domain for Regulation of Ciliogenesis
Authors: Oh Yoon Seon , Wang Eric J. , Gailey Casey D. , Brautigan David L. , Allen Benjamin L. , Fu Zheng
Published: July 2019

Loss-of-function mutations in the human ICK (intestinal cell kinase) gene cause dysfunctional primary cilia and perinatal lethality which are associated with human ciliopathies. The enzyme that we herein call CAPK (ciliopathy-associated protein kinase) is a serine/threonine protein kinase that has a highly conserved MAPK-like N-terminal catalytic domain and an unstructured C-terminal domain (CTD) whose functions are completely unknown. In this study, we demonstrate that truncation of the CTD impairs the ability of CAPK to interact with and phosphorylate its substrate, kinesin family member 3A (KIF3A). We also find that deletion of the CTD of CAPK compromises both localization to the primary cilium and negative regulation of ciliogenesis. Thus, CAPK substrate recognition, ciliary targeting, and ciliary function depend on the non-catalytic CTD of the protein which is predicted to be intrinsically disordered.
Investigations on Cationic Dye Degradation Using Iron-Doped Carbon Xerogel
Authors: Maicaneanu S. Andrada , McGhee Breanna , Stefan Razvan , Barbu-Tudoran Lucian , Sedwick Christopher , Lake Charles H.
Published: July 2019

Iron-doped carbon xerogels were prepared using sol-gel synthesis, with potassium-2,4-dihydroxybenzoate and formaldehyde as starting materials, followed by an ion exchange step. The obtained samples were characterized (XRD, FTIR, SED-EDX, TEM) and investigated as catalysts in heterogeneous Fenton and catalytic wet air oxidation (CWAO) processes. Experiments were conducted in the same conditions (0.1 g catalysts, 25 mL of 100 mg/L dye solution, 25 °C, initial solution pH, 3 h) in thermostated batch reaction tubes (shaking water bath, 50 rpm) at atmospheric pressure. A series of three cationic dyes were considered: Brilliant green (BG), crystal violet (CV), and methyl green (MG). Dyes and TOC removal efficiencies up to 99% and 92%, respectively, were obtained, in strong correlation with the iron content of the catalyst. Iron content measured in solution at the end of the reaction, indicated that its amount was less than 2 ppm for all tested catalysts.
A Class of Quadratic Polynomial Chaotic Maps and Their Fixed Points Analysis
Authors: Wang Chuanfu , Ding Qun
Published: July 2019

When chaotic systems are used in different practical applications, such as chaotic secure communication and chaotic pseudorandom sequence generators, a large number of chaotic systems are strongly required. However, for a lack of a systematic construction theory, the construction of chaotic systems mainly depends on the exhaustive search of systematic parameters or initial values, especially for a class of dynamical systems with hidden chaotic attractors. In this paper, a class of quadratic polynomial chaotic maps is studied, and a general method for constructing quadratic polynomial chaotic maps is proposed. The proposed polynomial chaotic maps satisfy the Li–Yorke definition of chaos. This method can accurately control the amplitude of chaotic time series. Through the existence and stability analysis of fixed points, we proved that such class quadratic polynomial maps cannot have hidden chaotic attractors.
The Complexity Entropy Analysis of a Supply Chain System Considering Recovery Rate and Channel Service
Authors: Li Qiuxiang , Shi Mengnan , Deng Qing , Huang Yi-min
Published: July 2019

In this paper, we study a dual-channel closed-loop supply chain in which a manufacturer considers the market waste products recovery and remanufacture, and a retailer considers provide services to customers. We build a Stackelberg game model and a centralized game model in a static and dynamic state, respectively, and analyze the two dynamic models by mathematical analysis and explore the stability and entropy of the two models using bifurcation, the basin of attraction, chaotic attractors, and so on. The influences of service level and profit distribution rate on the system’s profit are discussed. The theoretical results show that higher price adjustment speed will lead to the system lose stability with a larger entropy value. In the Stackelberg game model, the stability of the system increases as the service value and the recovery rate increases; in the centralized model, the stability of the system decreases with the increase of the service value and increases with the recovery rate increases. When the Stackelberg game model is in a stable state, the manufacturer’s profit increases first and then decreases, and the retailer’s profit first decreases and then increases as the service value of the retailer increases. The research will serve as good guidance for both the manufacturer and retailer in dual-channel closed-loop supply chains to improve decision making.
Micro-Motion Dynamics and Shape Parameters Estimation Based on an Infrared Signature Model of Spatial Targets
Authors: Wu Dongya , Lu Huanzhang , Zhao Bendong , Liu Junliang , Zhao Ming
Published: July 2019

Infrared imaging is widely applied in the discrimination of spatial targets. Extracting distinguishable features from the infrared signature of spatial targets is an important premise for this task. When a target in outer space experiences micro-motion, it causes periodic fluctuations in the observed infrared radiation intensity signature. Periodic fluctuations can reflect some potential factors of the received data, such as structure, dynamics, etc., and provide possible ways to analyze the signature. The purpose of this paper is to estimate the micro-motion dynamics and geometry parameters from the observed infrared radiation intensity signature. To this end, we have studied the signal model of the infrared radiation intensity signature, conducted the geometry and micro-motion models of the target, and we proposed a joint parameter estimation method based on optimization techniques. After analyzing the estimation results, we testified that the parameters of micro-motion and geometrical shape of the spatial target can be effectively estimated by our estimation method.
Study on the Possibilities of Natural Use of Ash Granulate Obtained from the Combustion of Pellets from Plant Biomass
Authors: Greinert Andrzej , Mrówczyńska Maria , Szefner Wojciech
Published: July 2019

As a step towards the diversification of electricity and heat sources, the EU countries suggest the use of biomass. The combustion of biomass poses the problem of the use of ash produced in the process. There are fluctuations in the properties of energetic biomass, which results in high variability of ash obtained by combustion, especially in terms of specific conductivity (EC) (8.1–9.7 mS·cm−1), the total content of components and their bioavailability. The combustion of biomass leads to large fluctuations in the total content of carbon in the ash (13.6%–28.6%). In this way, waste material with very different biological properties and cation exchange capacity is obtained. Ash from the combustion of biomass is an alkalizing material, rich in Ca, K and Mg carbonates (4.5%). The high average bioavailability of Pb (87.4%), Cd (63.1%) and Zn (46.9%) present in the ash is an environmental problem. The mobility of these heavy metals was reduced by half by the addition of bentonite during the process of ash granulation. With high doses of ash (4.4% of the mass of substrate), there is a significant bioaccumulation of Cd in the roots of Begonia semperflorens and Thuja occidentalis (1.0–3.8 mg·kg−1). Another disturbing issue is that during the cultivation of these plants, Cr is bioaccumulated in the roots (0.5–3.8 mg·kg−1).
Analysis and Design of an Air-Coupled DC Transformer with a Hybrid Modulation Control Method
Authors: Xu Song , Jiang Wei , Hashimoto Seiji
Published: July 2019

DC micro-grid is gaining increasing attention recently due to its highly efficient energy utilization and flexible energy exchange capabilities. In this paper, an air-coupled DC–DC transformer is proposed for the interconnection between the active load and the DC microgrid. The generic problems in an air-coupled power transfer system without ferromagnetic structure are discussed. A bidirectional half-bridge topology is also proposed to suit the characteristics of the stationary load and to realize the bidirectional power transfer between the active DC load and the DC grid. A Hybrid Modulation Method (HMM) is proposed; the small signal model is derived and linear control techniques are applied to the forward power transfer control, and phase model control is applied to the reverse power transfer model. The open-loop system is simulated by PSIM to get the characteristics of the forward and reverse transfer model, and the closed system is built in the MATLAB/SIMULINK to verify the effect of the forward frequency control method and the reverse phase control method. The prototype is built with a dsPIC controller, tests are performed to evaluate the characteristics of the transformer and the power flow control of the bidirectional power transfer.
Experimental Investigation on Thermal Performance of a PV/T-PCM (Photovoltaic/Thermal) System Cooling with a PCM and Nanofluid
Authors: Sarafraz M. , Safaei Mohammad , Leon Arturo , Tlili Iskander , Alkanhal Tawfeeq , Tian Zhe , Goodarzi Marjan , Arjomandi M.
Published: July 2019

In the present work, an experimental investigation is performed to assess the thermal and electrical performance of a photovoltaic solar panel cooling with multi-walled carbon nanotube–water/ethylene glycol (50:50) nano-suspension (MWCNT/WEG50). The prepared nanofluid was stabilized using an ultrasonic homogenizer together with the addition of 0.1vol% of nonylphenol ethoxylates at pH = 8.9. To reduce the heat loss and to improve the heat transfer rate between the coolant and the panel, a cooling jacket was designed and attached to the solar panel. It was also filled with multi-walled carbon nanotube–paraffin phase change material (PCM) and the cooling pipes were passed through the PCM. The MWCNT/WEG50 nanofluid was introduced into the pipes, while the nano-PCM was in the cooling jacket. The electrical and thermal power of the system and equivalent electrical–thermal power of the system was assessed at various local times and at different mass fractions of MWCNTs. Results showed that with an increase in the mass concentration of the coolant, the electricity and power production were promoted, while with an increase in the mass concentration of the nanofluid, the pumping power was augmented resulting in the decrease in the thermal–electrical equivalent power. It was identified that a MWCNT/WEG50 nano-suspension at 0.2wt% can represent the highest thermal and electrical performance of 292.1 W/m2. It was also identified that at 0.2wt%, ~45% of the electricity and 44% of the thermal power can be produced with a photovoltaic (PV) panel between 1:30 pm to 3:30 pm.
Structural Analysis of Large-Scale Vertical-Axis Wind Turbines, Part I: Wind Load Simulation
Authors: Lin Jinghua , Xu You-Lin , Xia Yong , Li Chao
Published: July 2019

When compared with horizontal-axis wind turbines, vertical-axis wind turbines (VAWTs) have the primary advantages of insensitivity to wind direction and turbulent wind, simple structural configuration, less fatigue loading, and easy maintenance. In recent years, large-scale VAWTs have attracted considerable attention. Wind loads on a VAWT must be determined prior to structural analyses. However, traditional blade element momentum theory cannot consider the effects of turbulence and other structural components. Moreover, a large VAWT cannot simply be regarded as a planar structure, and 3D computational fluid dynamics (CFD) simulation is computationally prohibitive. In this regard, a practical wind load simulation method for VAWTs based on the strip analysis method and 2D shear stress transport (SST) k-ω model is proposed. A comparison shows that the wind pressure and aerodynamic forces simulated by the 2D SST k-ω model match well with those obtained by 2.5D large eddy simulation (LES). The influences of mean wind speed profile, turbulence, and interaction of all structural components are considered. A large straight-bladed VAWT is taken as a case study. Wind loads obtained in this study will be applied to the fatigue and ultimate strength analyses of the VAWT in the companion paper.
Influence of Combustion Characteristics and Fuel Composition on Exhaust PAHs in a Compression Ignition Engine
Authors: Dandajeh Hamisu Adamu , Talibi Midhat , Ladommatos Nicos , Hellier Paul
Published: July 2019

This paper reports an experimental investigation into the effects of fuel composition on the exhaust emission of toxic polycyclic aromatic hydrocarbons (PAHs) from a diesel engine, operated at both constant fuel injection and constant fuel ignition modes. The paper quantifies the US EPA (United State Environmental Protection Agency) 16 priority PAHs produced from combustion of fossil diesel fuel and several model fuel blends of n-heptane, toluene and methyl decanoate in a single-cylinder diesel research engine based on a commercial light duty automotive engine. It was found that the level of total PAHs emitted by the various fuel blends decreased with increasing fuel ignition delay and premixed burn fraction, however, where the ignition delay of a fuel blend was decreased with use of an ignition improving additive the level of particulate phase PAH also decreased. Increasing the level of toluene present in the fuel blends decreased levels of low toxicity of two to four ring PAH, while displacing n-heptane with methyl decanoate increased particulate phase adsorbed PAH. Overall, the composition of the fuels investigated was found to have more influence on the concentration of exhaust PAHs formed than that of combustion characteristics, including ignition delay, peak heat release rate and the extent of the premixed burn fractions.
An Efficient Method to Predict Compressibility Factor of Natural Gas Streams
Authors: Gaganis Vassilis , Homouz Dirar , Maalouf Maher , Khoury Naji , Polychronopoulou Kyriaki
Published: July 2019

The gas compressibility factor, also known as the deviation or Z-factor, is one of the most important parameters in the petroleum and chemical industries involving natural gas, as it is directly related to the density of a gas stream, hence its flow rate and isothermal compressibility. Obtaining accurate values of the Z-factor for gas mixtures of hydrocarbons is challenging due to the fact that natural gas is a multicomponent, non-ideal system. Traditionally, the process of estimating the Z-factor involved simple empirical correlations, which often yielded weak results either due to their limited accuracy or due to calculation convergence difficulties. The purpose of this study is to apply a hybrid modeling technique that combines the kernel ridge regression method, in the form of the recently developed Truncated Regularized Kernel Ridge Regression (TR-KRR) algorithm, in conjunction with a simple linear-quadratic interpolation scheme to estimate the Z-factor. The model is developed using a dataset consisting of 5616 data points taken directly from the Standing–Katz chart and validated using the ten-fold cross-validation technique. Results demonstrate an average absolute relative prediction error of 0.04%, whereas the maximum absolute and relative error at near critical conditions are less than 0.01 and 2%, respectively. Most importantly, the obtained results indicate smooth, physically sound predictions of gas compressibility. The developed model can be utilized for the direct calculation of the Z-factor of any hydrocarbon mixture, even in the presence of impurities, such as N 2 , CO 2 , and H 2 S, at a pressure and temperature range that fully covers all upstream operations and most of the downstream ones. The model accuracy combined with the guaranteed continuity of the Z-factor derivatives with respect to pressure and temperature renders it as the perfect tool to predict gas density in all petroleum engineering applications. Such applications include, but are not limited to, hydrocarbon reserves estimation, oil and gas reservoir modeling, fluid flow in the wellbore, the pipeline system, and the surface processing equipment.
Effectiveness of a Power Factor Correction Policy in Improving the Energy Efficiency of Large-Scale Electricity Users in Ghana
Authors: Lotsu Samuel , Yoshida Yuichiro , Fukuda Katsufumi , He Bing
Published: July 2019

Confronting an energy crisis, the government of Ghana enacted a power factor correction policy in 1995. The policy imposes a penalty on large-scale electricity users, namely, special load tariff (SLT) customers of the Electricity Company of Ghana (ECG), whose power factor is below 90%. This paper investigates the impact of this policy on these firms’ power factor improvement by using panel data from 183 SLT customers from 1994 to 1997 and from 2012. To avoid potential endogeneity, this paper adopts a regression discontinuity design (RDD) with the power factor of the firms in the previous year as a running variable, with its cutoff set at the penalty threshold. The result shows that these large-scale electricity users who face the penalty because their power factor falls just short of the threshold are more likely to improve their power factor in the subsequent year, implying that the power factor correction policy implemented by Ghana’s government is effective.
Fireside Corrosion on Heat Exchanger Surfaces and Its Effect on the Performance of Gas-Fired Instantaneous Water Heaters
Authors: Huang Xiaomei , Sun Mengxiao , Kang Yinhu
Published: July 2019

The heat exchanger in a gas instantaneous water heater is a thermal device used for heat transfer from the high-temperature flue gas to the low-temperature water. The fireside corrosion, due to the reaction of acidic condensate formed on the heat exchanger surfaces and its metallic material, is one of the major hazards for gas instantaneous water heaters. This paper focuses on identifying and quantifying the fireside corrosion on the surface of heat exchangers in gas-fired instantaneous water heaters. Durability tests lasting for 2000 cycles were undertaken for five gas-fired instantaneous water heaters, which were different in terms of the heat input and coating of heat exchangers. The corrosion deposits on the surface of the heat exchangers were surveyed by several methods. The results show that the corrosion deposit grew as the test duration increased. The fins of the heat exchanger with a lead coating had been corroded and copper was exposed. Cu4(OH)6SO4 was the main corrosion product of heat exchangers without a lead coating, whereas PbSO4 was the main corrosion product of heat exchangers with a lead coating. The experiments demonstrate that the corrosion rate decreased with the increase of the heat input. The experiments also show that the thermal efficiency of gas instantaneous water heaters decreased by 2.4% to 6% at the end of the test duration.
An Unsupervised Classification Method for Flame Image of Pulverized Coal Combustion Based on Convolutional Auto-Encoder and Hidden Markov Model
Authors: Qiu Tian , Liu Minjian , Zhou Guiping , Wang Li , Gao Kai
Published: July 2019

Combustion condition monitoring is a fundamental and critical issue that needs to be addressed in the wide-load operation of coal-fired boilers. In this paper, an unsupervised classification framework based on the convolutional auto-encoder (CAE), the principal component analysis (PCA), and the hidden Markov model (HMM) is proposed to monitor the combustion condition with the uniformly spaced flame images, which are collected from the furnace combustion monitoring system. First, CAE is adopted to extract the features from the flame images, which obtain the sparse representations in the images. Then, PCA is applied to project the feature vectors into the orthogonal space for robustness and computation efficiency. Finally, a HMM is built to calculate the corresponding optimal states by learning the temporal behaviors in the compressed representations. A coal combustion adjustment experiment was conducted in a 660 MW opposed-firing boiler, and the sequential 14,400 flame images with three different combustion states were obtained to evaluate the effectiveness of the proposed approach. We tested six different compression dimensions of the latent variable z in the CAE model and ensured that the appropriate compress parameter was 1024. The proposed framework is compared with five other methods: the CAE + Gaussian mixture model (GMM), CAE + Kmean, the CAE + fuzzy c-mean method, CAE + HMM, and the traditional handcraft feature extraction method (TH) + HMM. The results show that the proposed framework has the highest classification accuracy (95.25% for the training samples and 97.36% for the testing samples) and has the best performance in recognizing the semi-stable state (85.67% for the training samples and 77.60% for the testing samples), indicating that the proposed framework is capable of identifying the combustion condition, changing when the combustion deteriorates as the coal feed rate falls.
Potential of Model-Free Control for Demand-Side Management Considering Real-Time Pricing
Authors: Zhou Suyang , Zou Fenghua , Wu Zhi , Gu Wei
Published: July 2019

This paper presents a detailed description of data predictive control (DPC) applied to a demand-side energy management system. Different from traditional model-based predictive control (MPC) algorithms, this approach introduces two model-free algorithms of artificial neural network (ANN) and random forest (RF) to make control strategy predictions on system operation, while avoiding the huge cost and effort associated with learning a grey/white box model of the physical system. The operating characteristics of electrical appliances, system energy consumption, and users’ comfort zones are also considered in the selected energy management system based on a real-time electricity pricing system. Case studies consisting of two scenarios (0% and 15% electricity price fluctuation) are delivered to demonstrate the effectiveness of the proposed approach. Simulation results demonstrate that the DPC controller based on ANN pays only 0.18% additional bill cost to maintain users’ comfort zones and system economy standardization while using only 0.096% optimization time cost compared with the MPC controller.
The Use of Satellite Information (MODIS/Aqua) for Phenological and Classification Analysis of Plant Communities
Authors: Ivanova Yulia , Kovalev Anton , Yakubailik Oleg , Soukhovolsky Vlad
Published: July 2019

Vegetation indices derived from remote sensing measurements are commonly used to describe and monitor vegetation. However, the same plant community can have a different NDVI (normalized difference vegetation index) depending on weather conditions, and this complicates classification of plant communities. The present study develops methods of classifying the types of plant communities based on long-term NDVI data (MODIS/Aqua). The number of variables is reduced by introducing two integrated parameters of the NDVI seasonal series, facilitating classification of the meadow, steppe, and forest plant communities in Siberia using linear discriminant analysis. The quality of classification conducted by using the markers characterizing NDVI dynamics during 2003–2017 varies between 94% (forest and steppe) and 68% (meadow and forest). In addition to determining phenological markers, canonical correlations have been calculated between the time series of the proposed markers and the time series of monthly average air temperatures. Based on this, each pixel with a definite plant composition can be characterized by only four values of canonical correlation coefficients over the entire period analyzed. By using canonical correlations between NDVI and weather parameters and employing linear discriminant analysis, one can obtain a highly accurate classification of the study plant communities.
Activating Mutations in PTPN11 and KRAS in Canine Histiocytic Sarcomas
Authors: Takada Marilia , Smyth Lauren A. , Thaiwong Tuddow , Richter Marlee , Corner Sarah M. , Schall Peter Z. , Kiupel Matti , Yuzbasiyan-Gurkan Vilma
Published: July 2019

While the genetic contributions to the predisposition of Bernese mountain dogs (BMDs) to histiocytic sarcoma (HS) remains unclear, some insights into key genetic drivers have been gained. Our group recently reported a mutation in the PTPN11 gene (E76K). We have now identified a second missense mutation in PTPN11 (G503V), and a mutation in KRAS (Q61H) present in HS cell lines. These mutations are associated with malignancies in humans, and known to be gain-of-function mutations that result in activation of the mitogen-activated protein kinase (MAPK) pathway. The goal of the present study was to evaluate the prevalence of these mutations in a large sample of HS cases from BMDs and golden retrievers, and in lymphoma cases, from a cohort of BMDs. Mutations in PTPN11 were present in HS in 41/96 (43%) BMDs, and in 3/13 (23%) golden retrievers. PTPN11 mutations E76K and G503V did not coexist in the same neoplasm. The KRAS mutation was much less frequent, with a prevalence of 3.1% (3/96). We did not identify either PTPN11 nor KRAS mutations in any of the lymphoma samples. These results point out the potential relevance of PTPN11 and KRAS mutations as activators of the oncogenic MAPK pathway for canine HS, particularly in BMDs.
The COPEWELL Rubric: A Self-Assessment Toolkit to Strengthen Community Resilience to Disasters
Authors: Schoch-Spana Monica , Gill Kimberly , Hosangadi Divya , Slemp Cathy , Burhans Robert , Zeis Janet , Carbone Eric G. , Links Jonathan
Published: July 2019

Measurement is a community endeavor that can enhance the ability to anticipate, withstand, and recover from a disaster, as well as foster learning and adaptation. This project’s purpose was to develop a self-assessment toolkit—manifesting a bottom-up, participatory approach—that enables people to envision community resilience as a concrete, desirable, and obtainable goal; organize a cross-sector effort to evaluate and enhance factors that influence resilience; and spur adoption of interventions that, in a disaster, would lessen impacts, preserve community functioning, and prompt a more rapid recovery. In 2016–2018, we engaged in a process of literature review, instrument development, stakeholder engagement, and local field-testing, to produce a self-assessment toolkit (or “rubric”) built on the Composite of Post-Event Well-being (COPEWELL) model that predicts post-disaster community functioning and resilience. Co-developing the rubric with community-based users, we generated self-assessment instruments and process guides that localities can more readily absorb and adapt. Applied in three field tests, the Social Capital and Cohesion materials equip users to assess this domain at different geo-scales. Chronicling the rubric’s implementation, this account sheds further light on tensions between community resilience assessment research and practice, and potential reasons why few of the many current measurement systems have been applied.
Building Vulnerability in a Changing Climate: Indoor Temperature Exposures and Health Outcomes in Older Adults Living in Public Housing during an Extreme Heat Event in Cambridge, MA
Authors: Williams Augusta A. , Spengler John D. , Catalano Paul , Allen Joseph G. , Cedeno-Laurent Jose G.
Published: July 2019

In the Northeastern U.S., future heatwaves will increase in frequency, duration, and intensity due to climate change. A great deal of the research about the health impacts from extreme heat has used ambient meteorological measurements, which can result in exposure misclassification because buildings alter indoor temperatures and ambient temperatures are not uniform across cities. To characterize indoor temperature exposures during an extreme heat event in buildings with and without central air conditioning (AC), personal monitoring was conducted with 51 (central AC, n = 24; non-central AC, n = 27) low-income senior residents of public housing in Cambridge, Massachusetts in 2015, to comprehensively assess indoor temperatures, sleep, and physiological outcomes of galvanic skin response (GSR) and heart rate (HR), along with daily surveys of adaptive behaviors and health symptoms. As expected, non-central AC units (Tmean = 25.6 °C) were significantly warmer than those with central AC (Tmean = 23.2 °C, p < 0.001). With higher indoor temperatures, sleep was more disrupted and GSR and HR both increased (p < 0.001). However, there were no changes in hydration behaviors between residents of different buildings over time and few moderate/several health symptoms were reported. This suggests both a lack of behavioral adaptation and thermal decompensation beginning, highlighting the need to improve building cooling strategies and heat education to low-income senior residents, especially in historically cooler climates.
Agronomic Management and Rice Varieties Controlling Cd Bioaccumulation in Rice
Authors: Chen Liangmei , Wu Wenge , Han Fengxiang , Li Jiangxia , Ye Wenling , Fu Huanhuan , Yan Yonghua , Ma Youhua , Wang Qiang
Published: July 2019

Selection of rice varieties and application of amendments are effective measures to ensure food safety. Here we report that in the non-Cd area, the grain quality of all rice varieties met the Chinese National Grain Safety Standards (CNGSS). In the high-Cd area, rice varieties showed significant different bioaccumulation of Cd with lower rice yields than those in non-Cd area with the average decrease of 31.1%. There was a negative correlation between grain Cd content and yields. A total of 19 rice varieties were selected as low Cd accumulating rice varieties and their Cd content met CNGSS in the low-Cd area. Six of them met CNGSS in the high-Cd area. The application of amendments significantly reduced Cd content in rice grains by 1.0–84.7% with an average of 52.6% and 13 of varieties met CNGSS. The amendments reduced available Cd content in soils by 1.1–75.8% but had no significant effects on rice yields. Therefore, the current study implied that proper agronomic management with selection of rice varieties and soil amendments was essential in controlling Cd accumulation in rice grains.
Women Reduce the Performance Difference to Men with Increasing Age in Ultra-Marathon Running
Authors: Waldvogel Karin J. , Nikolaidis Pantelis T. , Di Gangi Stefania , Rosemann Thomas , Knechtle Beat
Published: July 2019

Age and sex are well-known factors influencing ultra-marathon race performance. The fact that women in older age groups are able to achieve a similar performance as men has been documented in swimming. In ultra-marathon running, knowledge is still limited. The aim of this study was to analyze sex-specific performance in ultra-marathon running according to age and distance. All ultra-marathon races documented in the online database of the German Society for Ultra-Marathon from 1964 to 2017 for 50-mile races (i.e., 231,980 records from 91,665 finishers) and from 1953 to 2017 for 100-mile races (i.e., 107,445 records from 39,870 finishers) were analyzed. In 50-mile races, race times were 11.74 ± 1.95 h for men and 12.31 ± 1.69 h for women. In 100-mile races, race times were 26.6 ± 3.49 h for men and 27.47 ± 3.6 h for women. The sex differences decreased with older age and were smaller in 100-mile (4.41%) than in 50-mile races (9.13%). The overall age of peak performance was 33 years for both distances. In summary, women reduced the performance difference to men with advancing age, the relative difference being smaller in 100-mile compared to 50-mile races. These findings might aid coaches and ultra-marathon runners set long-term training goals considering their sex and age.
Coworking Spaces: The Better Home Office? A Psychosocial and Health-Related Perspective on an Emerging Work Environment
Authors: Robelski Swantje , Keller Helena , Harth Volker , Mache Stefanie
Published: July 2019

With the ongoing flexibilization of work, new trends concerning work outside the company’s premises such as coworking spaces are on the rise. Coworking spaces are designed to offer collaboration and community in furnished and equipped workspaces on a rental base. There is a growing body of scientific literature on coworking spaces with empirical results of qualitative and quantitative research. The present study adds to the latter by examining psychosocial demands experienced by coworkers in Germany based on a quantitative survey (n = 112). Among coworkers the home office was or still is another frequently used workplace. However, can the coworking space be seen as a better alternative to the home office in terms of work- and performance-related, social, environmental and health-related aspects? Results showed moderate to low psychosocial demands regarding quantitative workloads. Compared to the home office, the coworking space proved to be the preferred work arrangement. Results are discussed with regard to current literature and workplace design. In conclusion, coworking spaces can be seen as an alternative to the home office that was highly valued in the present sample. It is recommended to further emphasize aspects of work environment and ergonomics in order to create health-promoting and satisfying workplaces.