bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromechanical Transient Modeling and Control Strategy of Decentralized Hybrid HVDC Systems
Authors: Wang Guoteng , Xiao Huangqing , Xiao Liang , Zhang Zheren , Xu Zheng
Published: July 2019

This paper studies the electromechanical transient model and the control strategy of line commutated converter (LCC) and modular multilevel converter (MMC) based decentralized hybrid High Voltage Direct Current (HVDC) Transmission systems. The decentralized hybrid HVDC system is a new type of topology, and the related electromechanical transient model and control strategy have not been studied well. In this paper, the electromechanical transient model of a decentralized hybrid HVDC system is devloped through mathematical deduction. This model can be easily implemented in electromechanical transient simulation software and meet the time domain simulation requirements of large-scale systems. Then, in order to ensure the safe absorption of the DC power under various conditions, an optimal power flow model considering the decentralized hybrid HVDC system is proposed. Finally, the electromechanical transient model proposed in this paper is verified by the electromagnetic transient model, and the control strategy is validated in a modified New England 39-bus system.
An Application of Time-Dependent Holding Costs and System Reliability in a Multi-Item Sustainable Economic Energy Efficient Reliable Manufacturing System
Authors: Sarkar Mitali , Kim Sungjun , Jemai Jihed , Ganguly Baishakhi , Sarkar Biswajit
Published: July 2019

Sustainable efficient energy is the key factor of any sustainable manufacturing system. This study addresses a multi-item sustainable economic energy efficient reliable manufacturing quantity (MSEEERMQ) model. The manufacturing system produces defective products during long-runs, where those products may be reworked under the optimum effect of energy and carbon footprint with some costs. As all products are not sold immediately, the holding cost increases based on time. The management decides the system design variable to reduce energy consumption cost and increase system reliability under some time-dependent holding costs, and the optimum energy such that the maximum profit of the production model is obtained with a system reliability as a decision variable. The inflation and time-value of money are considered to calculate the cost of the production model under efficient energy. Using control theory, an Euler–Lagrange method is employed to obtain the sustainable critical path, which gives the optimal solution of the model. There are two lemmas to prove the global optimal solution of the model through the control theory. There is an illustrative example to test the model. Under different conditions there are other two examples with graphical representation and sensitivity analysis. Numerical studies reveal that maximum profit is obtained at the optimal value of the decision variable.
Analysis and Control of Wind Power Grid Integration Based on a Permanent Magnet Synchronous Generator Using a Fuzzy Logic System with Linear Extended State Observer
Authors: Ma Youjie , Tao Long , Zhou Xuesong , Li Wei , Shi Xueqi
Published: July 2019

Recently, wind energy conversion systems (WECSs) have attracted attention due to their effective application in renewable energy sources. It is a complex system with multi-variables, strong coupling, non-linearity, and variable parameters; however, traditional control systems are inadequate in answering the demands of complex systems. In order to solve the complexity and improve the transient stability during grid faults and power fluctuations, this paper proposes a fuzzy logic system with the linear extended state observer (FLS-LESO) applied to WECSs based on a permanent magnet synchronous generator (PMSG). The FLS-LESO consists of a fuzzy logic controller, a conventional PD controller, and the linear extended state observer (LESO). This paper analyzes the mathematical model of a wind power system and combines it with LESO to improve the estimation accuracy of the observer and further improve the control performance. In the simulation study, the control performance of the FLS-LESO was also tested under various operating conditions using the MATLAB/Simulink simulation platform to verify the correctness and effectiveness of the control system.
The Optimal Energy Dispatch of Cogeneration Systems in a Liberty Market
Authors: Lin Whei-Min , Yang Chung-Yuen , Tu Chia-Sheng , Huang Hsi-Shan , Tsai Ming-Tang
Published: July 2019

This paper proposes a novel approach toward solving the optimal energy dispatch of cogeneration systems under a liberty market in consideration of power transfer, cost of exhausted carbon, and the operation condition restrictions required to attain maximal profit. This paper investigates the cogeneration systems of industrial users and collects fuel consumption data and data concerning the steam output of boilers. On the basis of the relation between the fuel enthalpy and steam output, the Least Squares Support Vector Machine (LSSVM) is used to derive boiler and turbine Input/Output (I/O) operation models to provide fuel cost functions. The CO2 emission of pollutants generated by various types of units is also calculated. The objective function is formulated as a maximal profit model that includes profit from steam sold, profit from electricity sold, fuel costs, costs of exhausting carbon, wheeling costs, and water costs. By considering Time-of-Use (TOU) and carbon trading prices, the profits of a cogeneration system in different scenarios are evaluated. By integrating the Ant Colony Optimization (ACO) and Genetic Algorithm (GA), an Enhanced ACO (EACO) is proposed to come up with the most efficient model. The EACO uses a crossover and mutation mechanism to alleviate the local optimal solution problem, and to seek a system that offers an overall global solution using competition and selection procedures. Results show that these mechanisms provide a good direction for the energy trading operations of a cogeneration system. This approach also provides a better guide for operation dispatch to use in determining the benefits accounting for both cost and the environment in a liberty market.
Optimising the Operation of Tidal Range Schemes
Authors: Xue Jingjing , Ahmadian Reza , Falconer Roger
Published: July 2019

Marine renewable energy, including tidal renewable energy, is one of the less exploited sources of energy that could contribute to energy demand, while reducing greenhouse gas emissions. Amongst several proposals to build tidal range structure (TRS), a tidal lagoon has been proposed for construction in Swansea Bay, in the South West of the UK, but this scheme was recently rejected by the UK government due to the high electricity costs. This decision makes the optimisation of such schemes more important for the future. This study proposes various novel approaches by breaking the operation into small components to optimise the operation of TRS using a widely used 0-D modelling methodology. The approach results in a minimum 10% increase in energy output, without the inclusion of pumping, in comparison to the maximum energy output using a similar operation for all tides. This increase in energy will be approximately 25% more when pumping is included. The optimised operation schemes are used to simulate the lagoon operation using a 2-D model and the differences between the results are highlighted.
Optimizing the 3D Distributed Climate inside Greenhouses Using Multi-Objective Optimization Algorithms and Computer Fluid Dynamics
Authors: Li Kangji , Xue Wenping , Mao Hanping , Chen Xu , Jiang Hui , Tan Gang
Published: July 2019

As one of the major production facilities in agriculture, a greenhouse has many spatial distributed factors influencing crop growth and energy consumption, such as temperature field, air flow pattern, CO 2 concentration distribution, etc. By introducing a hybrid computational fluid dynamics–evolutionary algorithm (CFD-EA) method, this paper constructs a micro-climate model of greenhouse with main environmental parameters optimized. Considering environmental factors’ spatial influences together with energy usage simultaneously, the optimal solutions of control variables for crop growth are calculated. A commercial greenhouse located in east China is chosen for the method validation. Field experiments using temperature/velocity sensor matrix are carried out for CFD accuracy investigation. On this basis, the proposed optimization method is employed to search for the optimal control variables and parameters corresponding to the environmental Pareto frontier. By the proposed multi-objective scheme, we believe the method can provide set point basis for the design and regulation of large/medium-sized greenhouse production with high spatial resolution.
A Distributed Energy Trading Authentication Mechanism Based on a Consortium Blockchain
Authors: Che Zheng , Wang Yu , Zhao Juanjuan , Qiang Yan , Ma Yue , Liu Jihua
Published: July 2019

With the rapid development of the energy internet, the transaction of distributed renewable energy (DRE) is playing an increasingly important role in the energy market. However, in the transaction model of distributed renewable energy combined with public blockchain technology, nodes in the trading network can join or leave the network at any time without any permission, which hinders the regulation of electricity institutions. Corresponding to the transaction principle, a distributed renewable energy transaction authentication mechanism based on consortium blockchain is proposed in this paper. First, certificate authority nodes were set in the transaction network to provide nodes with access authority by controlling the public keys and private keys of trading participants so that they can complete their identity authentication. Next, essential chaincodes in the transaction authentication were designed and deployed on a Hyperledger Fabric blockchain site, and a simulation experiment of a simple DRE transaction was used to elaborate the details on the transaction process. Finally, the proposed model was evaluated according to its performance and proved to be practical and effective.
Stakeholders’ Perspectives to Support the Integration of Ecosystem Services in Spatial Planning in Switzerland
Authors: Jaligot Rémi , Chenal Jérôme
Published: July 2019

Integrating the concept of ecosystem services (ES) into spatial planning is an opportunity to make land use and management choices that maximize the delivery of multiple ES. The assessment of social demand can be useful for the identification of priority areas or potential conflicts among stakeholders. We used Q-methodology to understand stakeholder perspectives on ES to facilitate their integration into spatial planning in the canton of Vaud, Switzerland. Three perspectives, utilitarian, cultural and protective, were analyzed and used to discuss potential implications for spatial planning. First, ecosystem multifunctionality and synergies among ES should be emphasized. Second, the food production system should move away from a productive-only approach, to a system that protects soils and their functions. Providing a paradigm change, arable land could be protected to the same level as forests and farmers could be incentivized further to change their practices. Finally, our findings show a potential over-interpretation of the importance of cultural ES in current planning policies, as most participants would be ready to change their behaviors to preserve biological functions. It would be useful to conduct a similar study in other cantons to ensure that the results are fully representative of the current situation in Switzerland.
Modulation of the Expression of Immune-related Gene in Atlantic and Coho Salmon during Infestation with the Sea lice Caligus rogercresseyi
Authors: Pontigo Juan Pablo , Saravia Julia , Oyarzún Ricardo , González Margarita P. , Hawes Christopher , Morera Francisco J. , Pino Jorge , Wadsworth Simon , Muñoz Jose Luis P. , Vargas-Chacoff Luis
Published: July 2019

Caligus rogercresseyi, a marine ectoparasite, causes notable economic losses for the Chilean salmonid industry. Nevertheless, the immunological responses of infected fish remain poorly understood, including proinflammatory cytokine generation and the respective modulatory effects of various cytokine receptors. This study evaluated mRNA expression of the NLRC5, major histocompatibility complex (MHC) class II, I-kappa-B-alpha, a regulatory that inhibits NF-kappa-B, and proinflammatory cytokines (IL-1β and IL-18) in the liver and muscle of Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynchus kisutch) during a time-course C. rogercresseyi infestation trial. All assessed mRNA were strongly regulated during infestation, but S. salar showed up-regulated expression, possibly accounting for the high infestation vulnerability of this salmonid. In conclusion, this work helps to understand the modulation of the expression of different transcripts involved over short periods of C. rogercresseyi infestation in two salmonid species (S. salar and O. kisutch).
Not Getting What You Want? The Impact of Income Comparisons on Subjective Well-Being—Findings of a Population-Based Longitudinal Study in Germany
Authors: Hajek André , König Hans-Helmut
Published: July 2019

Previous studies have mainly focused on interindividual income comparisons (e.g., comparisons with colleagues or neighbors), whereas intraindividual income comparisons (i.e., difference between factual income and expectations) have rarely been investigated in well-being research. Thus, the aim of this study was to investigate the role of intraindividual income comparisons on subjective well-being (negative/positive emotions and life satisfaction) longitudinally. Data from 2005 to 2013 (biannually) were used from the German Socio-Economic Panel (GSOEP), a nationally representative, longitudinal study. Affective well-being (negative and positive emotions) were quantified by using the affective well-being scale-SOEP. Life satisfaction was quantified using the widely used one-item form. Intraindividual income comparisons were analyzed by using the distance between the own individual income and fair income (“how high would your net income have to be in order to be just”). We tested whether negative (i.e., factual income was lower than their self-rated just income) and positive income comparisons (otherwise) affect the outcome measures differently. Fixed effects regressions showed that positive emotions increased with positive income comparisons in the total sample (β = 0.16, p < 0.05). In contrast, negative income comparisons neither affect negative emotions nor satisfaction with life. Strategies to shift income expectations might be beneficial for increasing positive emotions.
The Mediating Role of Self-Concept between Sports-Related Physical Activity and Mathematical Achievement in Fourth Graders
Authors: Dapp Laura C. , Roebers Claudia M.
Published: July 2019

Being physically active has many benefits for children and adolescents. It is essential for various aspects of physical and mental health, and also positively influences academic performance and school achievement. In addressing the still incomplete understanding of the link between physical activity (PA) and academic achievement, the present study scrutinized the open issues regarding different roles of PA type and PA duration within the relation between self-reported PA and objectively measured mathematical achievement in fourth graders. As to the type of PA, the current study distinguished between structured and unstructured sports activities children perform in their leisure time. Moreover, the current study investigated the indirect effect of PA on mathematical achievement by controlling for the mathematical self-concept as a mediating variable. Results showed PA to be positively related to mathematical outcomes if implemented in a structured setting and pursued for at least two hours per week. As to the mediation, the results revealed a full mediation, indicating PA to improve mathematical self-concept, which, in turn, positively affected mathematical achievement. Thus, engaging in structured PA for two hours or more a week may have additional benefits for children’s and adolescents’ self-concept in a way that is favorable and encouraging for promoting their academic achievement.
The Protective Role of Heme Oxygenase-1 in Atherosclerotic Diseases
Authors: Kishimoto Yoshimi , Kondo Kazuo , Momiyama Yukihiko
Published: July 2019

Heme oxygenase-1 (HO-1) is an intracellular enzyme that catalyzes the oxidation of heme to generate ferrous iron, carbon monoxide (CO), and biliverdin, which is subsequently converted to bilirubin. These products have anti-inflammatory, anti-oxidant, anti-apoptotic, and anti-thrombotic properties. Although HO-1 is expressed at low levels in most tissues under basal conditions, it is highly inducible in response to various pathophysiological stresses/stimuli. HO-1 induction is thus thought to be an adaptive defense system that functions to protect cells and tissues against injury in many disease settings. In atherosclerosis, HO-1 may play a protective role against the progression of atherosclerosis, mainly due to the degradation of pro-oxidant heme, the generation of anti-oxidants biliverdin and bilirubin and the production of vasodilator CO. In animal models, a lack of HO-1 was shown to accelerate atherosclerosis, whereas HO-1 induction reduced atherosclerosis. It was also reported that HO-1 induction improved the cardiac function and postinfarction survival in animal models of heart failure or myocardial infarction. Recently, we and others examined blood HO-1 levels in patients with atherosclerotic diseases, e.g., coronary artery disease (CAD) and peripheral artery disease (PAD). Taken together, these findings to date support the notion that HO-1 plays a protective role against the progression of atherosclerotic diseases. This review summarizes the roles of HO-1 in atherosclerosis and focuses on the clinical studies that examined the relationships between HO-1 levels and atherosclerotic diseases.
The Role of Prep1 in the Regulation of Mesenchymal Stromal Cells
Authors: Maroni Giorgia , Panetta Daniele , Luongo Raffaele , Krishnan Indira , La Rosa Federica , Campani Daniela , Salvadori Piero , Iozzo Patricia , Blasi Francesco , Penkov Dmitry , Levantini Elena , Magli Maria
Published: July 2019

Molecular mechanisms governing cell fate decision events in bone marrow mesenchymal stromal cells (MSC) are still poorly understood. Herein, we investigated the homeobox gene Prep1 as a candidate regulatory molecule, by adopting Prep1 hypomorphic mice as a model to investigate the effects of Prep1 downregulation, using in vitro and in vivo assays, including the innovative single cell RNA sequencing technology. Taken together, our findings indicate that low levels of Prep1 are associated to enhanced adipogenesis and a concomitant reduced osteogenesis in the bone marrow, suggesting Prep1 as a potential regulator of the adipo-osteogenic differentiation of mesenchymal stromal cells. Furthermore, our data suggest that in vivo decreased Prep1 gene dosage favors a pro-adipogenic phenotype and induces a “browning” effect in all fat tissues.
Behavioral Disturbances in Dementia and Beyond: Time for a New Conceptual Frame?
Authors: Ambrogio Federico , Martella Lucia Anna , Odetti Patrizio , Monacelli Fiammetta
Published: July 2019

Alzheimer’s disease and vascular dementia are estimated to be the most common causes of dementia, although mixed dementia could represent the most prevalent form of dementia in older adults aged more than 80 years. Behavioral disturbances are common in the natural history of dementia. However, so far, there is a paucity of studies that investigated the causal association between behavioral psychological symptoms of dementia and dementia sub-types, due to the high heterogeneity of methodology, study design and type of clinical assessment. To understand the scant evidence on such a relevant clinical issue, it could be hypothesized that a new shifting paradigm could result in a better identification of the relationship between behavioral disturbances and dementia. This narrative review provides an update of evidence on the behavioral patterns associated with different dementia sub-types and offers a potential future perspective as common ground for the development of new translational studies in the field of behavioral disturbances in dementia and the appropriateness of psychoactive treatments.
MicroRNA Profiling During Neural Differentiation of Induced Pluripotent Stem Cells
Authors: Kulcenty Katarzyna , Wroblewska Joanna P , Rucinski Marcin , Kozlowska Emilia , Jopek Karol , Suchorska Wiktoria M
Published: July 2019

MicroRNAs (miRNA) play an essential role in the regulation of gene expression and influence signaling networks responsible for several cellular processes like differentiation of pluripotent stem cells. Despite several studies on the neurogenesis process, no global analysis of microRNA expression during differentiation of induced pluripotent stem cells (iPSC) to neuronal stem cells (NSC) has been done. Therefore, we compared the profile of microRNA expression in iPSC lines and in NSC lines derived from them, using microarray-based analysis. Two different protocols for NSC formation were used: Direct and two-step via neural rosette formation. We confirmed the new associations of previously described miRNAs in regulation of NSC differentiation from iPSC. We discovered upregulation of miR-10 family, miR-30 family and miR-9 family and downregulation of miR-302 and miR-515 family expression. Moreover, we showed that miR-10 family play a crucial role in the negative regulation of genes expression belonging to signaling pathways involved in neural differentiation: WNT signaling pathway, focal adhesion, and signaling pathways regulating pluripotency of stem cells.
Innate Immune Cells and Toll-like Receptor–Dependent Responses at the Maternal–Fetal Interface
Authors: Olmos-Ortiz Andrea , Flores-Espinosa Pilar , Mancilla-Herrera Ismael , Vega-Sánchez Rodrigo , Díaz Lorenza , Zaga-Clavellina Verónica
Published: July 2019

During pregnancy, the placenta, the mother and the fetus exploit several mechanisms in order to avoid fetal rejection and to maintain an immunotolerant environment throughout nine months. During this time, immune cells from the fetal and maternal compartments interact to provide an adequate defense in case of an infection and to promote a tolerogenic milieu for the fetus to develop peacefully. Trophoblasts and decidual cells, together with resident natural killer cells, dendritic cells, Hofbauer cells and other macrophages, among other cell types, contribute to the modulation of the uterine environment to sustain a successful pregnancy. In this review, the authors outlined some of the various roles that the innate immune system plays at the maternal–fetal interface. First, the cell populations that are recruited into gestational tissues and their immune mechanisms were examined. In the second part, the Toll–like receptor (TLR)–dependent immune responses at the maternal–fetal interface was summarized, in terms of their specific cytokine/chemokine/antimicrobial peptide expression profiles throughout pregnancy.
Arterial Stiffness Assessed by Cardio-Ankle Vascular Index
Authors: Namba Takayuki , Masaki Nobuyuki , Takase Bonpei , Adachi Takeshi
Published: July 2019

Arterial stiffness is an age-related disorder. In the medial layer of arteries, mechanical fracture due to fatigue failure for the pulsatile wall strain causes medial degeneration vascular remodeling. The alteration of extracellular matrix composition and arterial geometry result in structural arterial stiffness. Calcium deposition and other factors such as advanced glycation end product-mediated collagen cross-linking aggravate the structural arterial stiffness. On the other hand, endothelial dysfunction is a cause of arterial stiffness. The biological molecular mechanisms relating to aging are known to involve the progression of arterial stiffness. Arterial stiffness further applies stress on large arteries and also microcirculation. Therefore, it is closely related to adverse outcomes in cardiovascular and cerebrovascular system. Cardio-ankle vascular index (CAVI) is a promising diagnostic tool for evaluating arterial stiffness. The principle is based on stiffness parameter β, which is an index intended to assess the distensibility of carotid artery. Stiffness parameter β is a two-dimensional technique obtained from changes of arterial diameter by pulse in one section. CAVI applied the stiffness parameter β to all of the arterial segments between heart and ankle using pulse wave velocity. CAVI has been commercially available for a decade and the clinical data of its effectiveness has accumulated. The characteristics of CAVI differ from other physiological tests of arterial stiffness due to the independency from blood pressure at the time of examination. This review describes the pathophysiology of arterial stiffness and CAVI. Molecular mechanisms will also be covered.
Melanocyte Activation Mechanisms and Rational Therapeutic Treatments of Solar Lentigos
Authors: Imokawa Genji
Published: July 2019

To characterize the pathobiology of solar lentigos (SLs), analyses by semiquantitative RT-PCR, Western blotting, and immunohistochemistry revealed the upregulated expression of endothelin (EDN)-1/endothelin B receptors (EDNBRs), stem cell factor (SCF)/c-KIT, and tumor necrosis factor (TNF)α in the lesional epidermis, which contrasted with the downregulated expression of interleukin (IL) 1α. These findings strongly support the hypothesis that previous repeated UVB exposure triggers keratinocytes to continuously produce TNFα. TNFα then stimulates the secretion of EDNs and the production of SCF in an autocrine fashion, leading to the continuous melanogenic activation of neighboring melanocytes, which causes SLs. A clinical study of 36 patients with SLs for six months treated with an M. Chamomilla extract with a potent ability to abrogate the EDN1-induced increase in DNA synthesis and melanization of human melanocytes in culture revealed a significant improvement in pigment scores and color differences expressed as L values. Another clinical study using a tyrosinase inhibitor L-ascorbate-2-phosphate 3 Na (ASP) demonstrated that L values of test lotion (6% APS)-treated skin significantly increased in SLs and in non-lesional skin with a significantly higher ΔL value in SLs when compared with non-lesional skin. The sum of these findings strongly suggests that combined topical treatment with EDN signaling blockers and tyrosinase inhibitors is a desirable therapeutic choice for SLs.
Light Stress-Induced Increase of Sphingosine 1-Phosphate in Photoreceptors and Its Relevance to Retinal Degeneration
Authors: Terao Ryo , Honjo Megumi , Ueta Takashi , Obinata Hideru , Izumi Takashi , Kurano Makoto , Yatomi Yutaka , Koso Hideto , Watanabe Sumiko , Aihara Makoto
Published: July 2019

Sphingosine 1-phosphate (S1P) is a potent lipid mediator that modulates inflammation and angiogenesis. In this study, we investigated the possible involvement of S1P in the pathology of light-induced retinal degeneration in vivo and in vitro. The intracellular S1P and sphingosine kinase (SphK) activity in a photoreceptor cell line (661W cells) was significantly increased by exposure to light. The enhancement of SphK1 expression was dependent on illumination, and all-trans-retinal significantly promoted SphK1 expression. S1P treatment reduced protein kinase B (Akt) phosphorylation and increased the protein expression of cleaved caspase-3, and induced photoreceptor cell apoptosis. In vivo, light exposure enhanced the expression of SphK1 in the outer segments of photoreceptors. Intravitreal injection of a SphK inhibitor significantly suppressed the thinning of the outer nuclear layer and ameliorated the attenuation of the amplitudes of a-waves and b-waves of electroretinograms during light-induced retinal degeneration. These findings imply that light exposure induces the synthesis of S1P in photoreceptors by upregulating SphK1, which is facilitated by all-trans-retinal, causing retinal degeneration. Inhibition of this enhancement may be a therapeutic target of outer retinal degeneration, including age-related macular degeneration.
The Effect of Health-Related Behaviors on Disease Progression and Mortality in Early Stages of Chronic Kidney Disease: A Korean Nationwide Population-Based Study
Authors: Lee Yookyung , Kwon SuYeon , Moon Jong Joo , Han Kyungdo , Paik Nam-Jong , Kim Won-Seok
Published: July 2019

A healthy life style is associated with decreased risk of chronic kidney disease (CKD) and mortality in the general population. However, there is no definitive evidence of the benefits of physical activity and other health-related behaviors in the early-stage of CKD. This study aimed to explore the association between health-related behaviors and end-stage renal disease (ESRD) and mortality in the early stages of CKD. The National Health Insurance Service (NHIS) database from 1 January 2009 to 31 December 2016 was used to screen 83,470 subjects with early stage CKD. Cox proportional hazard regression analysis was used to evaluate the association between health-related behaviors and ESRD and death. Kaplan–Meier curves for mortality and ESRD were plotted according to the physical activity, smoking status, and alcohol consumption pattern. Risk of death decreased significantly in subjects who engaged in sufficient physical activity (adjusted Hazard Ratio (HR) 0.73; 95% CI: 0.64–0.83; p < 0.001). Risk of ESRD and death increased significantly in the current smoker with adjusted HR of 1.44 (95% CI: 1.06–1.95; p < 0.02) and 1.61 (95% CI: 1.44–1.80; p < 0.001) respectively. Therefore, systematic interventions to encourage physical activity and smoking cessation need to be actively considered in the early stages of CKD.
Special Issue: Thermo-Mechanical Behaviour of Structural Lightweight Alloys
Authors: Requena Guillermo
Published: July 2019

The need to reduce the ecological footprint of (water, land, air) vehicles in this era of climate change requires pushing the limits in the development of lightweight structures and materials [...]
Impact of Perfluoro and Alkylphosphonic Self-Assembled Monolayers on Tribological and Antimicrobial Properties of Ti-DLC Coatings
Authors: Cichomski Michal , Prowizor Milena , Borkowska Ewelina , Piwoński Ireneusz , Jędrzejczak Anna , Dudek Mariusz , Batory Damian , Wrońska Natalia , Lisowska Katarzyna
Published: July 2019

The diamond-like carbon (DLC) coatings containing 1.6%, 5.3% and 9.4 at.% of Ti deposited by the radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on the silicon substrate were modified by n-decylphosphonic acid (DP) and 1H, 1H, 2H and 2H-perfluorodecylphosphonic acid (PFDP). The presence of perfluoro and alkylphosphonic self-assembled monolayers prepared by the liquid phase deposition (LPD) technique was confirmed by Fourier transform infrared spectroscopy (FTIR). It was shown that DP and PFDP monolayers on the surface of titanium incorporated diamond-like carbon (Ti-DLC) coatings had a huge influence on their wettability, friction properties, stability under phosphate- and tris-buffered saline solutions and on antimicrobial activity. It was also found that the dispersive component of surface free energy (SFE) had a significant influence on the value of the friction coefficient and the percentage value of the growth inhibition of bacteria. The dispersive component of SFE caused a reduction in the growth of bacteria and the friction coefficient in mili- and nano-newton load range. Additionally, both self-assembled monolayers prepared on Ti-DLC coatings strongly reduced bacterial activity by up to 95% compared to the control sample.
Refinements of Majorization Inequality Involving Convex Functions via Taylor’s Theorem with Mean Value form of the Remainder
Authors: Wu Shanhe , Khan Muhammad Adil , Haleemzai Hidayat Ullah
Published: July 2019

The aim of this paper is to establish some refined versions of majorization inequality involving twice differentiable convex functions by using Taylor theorem with mean-value form of the remainder. Our results improve several results obtained in earlier literatures. As an application, the result is used for deriving a new fractional inequality.
Conformal and Geodesic Mappings onto Some Special Spaces
Authors: Berezovski Volodymyr , Cherevko Yevhen , Rýparová Lenka
Published: July 2019

In this paper, we consider conformal mappings of Riemannian spaces onto Ricci-2-symmetric Riemannian spaces and geodesic mappings of spaces with affine connections onto Ricci-2-symmetric spaces. The main equations for the mappings are obtained as a closed system of Cauchy-type differential equations in covariant derivatives. We find the number of essential parameters which the solution of the system depends on. A similar approach was applied for the case of conformal mappings of Riemannian spaces onto Ricci-m-symmetric Riemannian spaces, as well as geodesic mappings of spaces with affine connections onto Ricci-m-symmetric spaces.
Non-Stationary Fractal Interpolation
Authors: Massopust Peter
Published: July 2019

We introduce the novel concept of a non-stationary iterated function system by considering a countable sequence of distinct set-valued maps { F k } k ∈ N where each F k maps H ( X ) → H ( X ) and arises from an iterated function system. Employing the recently-developed theory of non-stationary versions of fixed points and the concept of forward and backward trajectories, we present new classes of fractal functions exhibiting different local and global behavior and extend fractal interpolation to this new, more flexible setting.
Autothermal Thermophilic Aerobic Digestion (ATAD) for Heat, Gas, and Production of a Class A Biosolids with Fertilizer Potential
Authors: Pembroke J. Tony , Ryan Michael P.
Published: July 2019

Autothermal thermophilic aerobic digestion (ATAD) is a microbial fermentation process characterized as a tertiary treatment of waste material carried out in jacketed reactors. The process can be carried out on a variety of waste sludge ranging from human, animal, food, or pharmaceutical waste where the addition of air initiates aerobic digestion of the secondary treated sludge material. Digestion of the sludge substrates generates heat, which is retained within the reactor resulting in elevation of the reactor temperature to 70–75 °C. During the process, deamination of proteinaceous materials also occurs resulting in liberation of ammonia and elevation of pH to typically pH 8.4. These conditions result in a unique microbial consortium, which undergoes considerable dynamic change during the heat-up and holding phases. The change in pH and substrate as digestion occurs also contributes to this dynamic change. Because the large reactors are not optimized for aeration, and because low oxygen solubility at elevated temperatures occurs, there are considerable numbers of anaerobes recovered which also contributes to the overall digestion. As the reactors are operated in a semi-continuous mode, the reactors are rarely washed, resulting in considerable biofilm formation. Equally, because of the fibrous nature of the sludge, fiber adhering organisms are frequently found which play a major role in the overall digestion process. Here, we review molecular tools needed to examine the ATAD sludge consortia, what has been determined through phylogenetic analysis of the consortia and the nature of the dynamics occurring within this unique fermentation environment.
Robust Normalization of Luciferase Reporter Data
Authors: Repele Andrea , Manu
Published: July 2019

Transient Luciferase reporter assays are widely used in the study of gene regulation and intracellular cell signaling. In order to control for sample-to-sample variation in luminescence arising from variability in transfection efficiency and other sources, an internal control reporter is co-transfected with the experimental reporter. The luminescence of the experimental reporter is normalized against the control by taking the ratio of the two. Here we show that this method of normalization, “ratiometric”, performs poorly when the transfection efficiency is low and leads to biased estimates of relative activity. We propose an alternative methodology based on linear regression that is much better suited for the normalization of reporter data, especially when transfection efficiency is low. We compare the ratiometric method against three regression methods on both simulated and empirical data. Our results suggest that robust errors-in-variables (REIV) regression performs the best in normalizing Luciferase reporter data. We have made the R code for Luciferase data normalization using REIV available on GitHub.
Comparison of Experimental and Modeled EMI Shielding Properties of Periodic Porous xGNP/PLA Composites
Authors: Bregman Avi , Michielssen Eric , Taub Alan
Published: July 2019

Microwave absorbing materials, particularly ones that can achieve high electromagnetic interference (EMI) absorption while minimizing weight and thickness are in high demand for many applications. Herein we present an approach that relies on the introduction of periodically placed air-filled pores into polymer composites in order to reduce material requirements and maximize microwave absorption. In this study, graphene nano platelet (xGNP)/poly-lactic acid (PLA) composites with different aspect ratio fillers were characterized and their complex electromagnetic properties were extracted. Using these materials, we fabricated non-perfect electrical conductor (PEC) backed, porous composites and explored the effect of filler aspect ratio and pore geometry on EMI shielding properties. Furthermore, we developed and experimentally verified a computational model that allows for rigorous, high-throughput optimization of absorbers with periodic porous geometries. Finally, we extend the modeling approach to explore the effect of pore addition on PEC-backed composites. Our composite structures demonstrated decreased fractions of reflected power and increased fractions of absorbed power over the majority of the X Band due to the addition of periodically arranged cylindrical pores. Furthermore, we showed that for xGNP/PLA composite material, reflection loss can be increased by as much as 13 dB through the addition of spherical pores. The ability to adjust shielding properties through the fabrication of polymer composites with periodically arranged pores opens new strategies for the modeling and development of new microwave absorption materials.
Synthesis of Silane-Based Poly(thioether) via Successive Click Reaction and Their Applications in Ion Detection and Cell Imaging
Authors: Gou Zhiming , Zhang Xiaomei , Zuo Yujing , Lin Weiying
Published: July 2019

A series of poly(thioether)s containing silicon atom with unconventional fluorescence were synthesized via successive thiol click reaction at room temperature. Although rigid π-conjugated structure did not exist in the polymer chain, the poly(thioether)s exhibited excellent fluorescent properties in solutions and showed visible blue fluorescence in living cells. The strong blue fluorescence can be attributed to the aggregation of lone pair electron of heteroatom and coordination between heteroatom and Si atom. In addition, the responsiveness of poly(thioether) to metal ions suggested that the selectivity of poly(thioether) to Fe3+ ion could be enhanced by end-modifying with different sulfhydryl compounds. This study further explored their application in cell imaging and studied their responsiveness to Fe3+ in living cells. It is expected that the described synthetic route could be extended to synthesize novel poly(thioether)s with superior optical properties. Their application in cell imaging and ion detection will broaden the range of application of poly(thioether)s.
Coordination Dynamics and Thermal Stability with Aminal Metallogels and Liquids
Authors: Boul Peter J. , Rasner Diana K. , Jarowski Peter D. , Thaemlitz Carl J.
Published: July 2019

In this article, we review a dynamic covalent gel system developed as a high temperature well construction fluid. The key gel/fluid phase changes and related materials properties are addressable via the constitutional and coordination dynamics of the equilibrium and non-equilibrium molecular species comprising the material. The interplay between these species and external stimuli leads to material adaptability. Specifically, the introduction of metal ions into a non-equilibrium hemiaminal gel reverts this phase into a non-equilibrium liquid. When heated, this liquid transforms itself catalytically into the thermodynamically favoured closed-ring polyhexahydrotriazine (PHT) gel product. The temperature stability of different PHT gel formulations is evaluated as a function of the inclusion of various salts. It is possible to revert this thermodynamic PHT gel back into a liquid. This pH dependent transformation depends on the R groups linking the hexahydrotriazines (HTs) to one another. While polyethylene glycol (PEG) based PHT gels revert to liquids with water and mild protonation conditions, in comparison, polypropylene glycol (PPG) based gels require stronger acid conditions with heat, or a different more nucleophilically driven ring-opening mechanism by, for example, phosphines. The covalent dynamic chemistry in this chemical system gives way to many possible applications in addition to the high temperature solution-gelation (sol-gels) for which it has been primarily designed.
Using Verbal Art to Deal with Conflicts: Women’s Voices on Family and Kinship in Kāmākhyā (Assam)
Authors: Arrago-Boruah Emilie
Published: July 2019

Analyzing two women’s rituals in which verbal art on family and kinship is prominent, this article explores situations in which tales and songs in Assamese are staged by newly married and about-to-be-married young women. Active participation in stories and song sessions, under the guidance of older storytellers or singers, imparts practical knowledge to young women about the possible ways by which to retaliate against male domination and domestic tensions with one’s mother-in-law. The young women who participate are not merely engaged in the performance but are also encouraged to place themselves in the story. This performance study, based on the ecology of Assam and the annual calendar of festivals at the great temple of the goddess Kāmākhyā, combines the exploration of these narratives with the observation of rituals. It also seeks to question whether social language practices endow women with the power to affirm themselves and with the knowledge, through ritual performance, to deal with conflict. Finally, it shows how the use of an original ritual object—a small house—can be put into perspective with the concept of “house” as understood in particular by Lévi-Strauss.
On the Realistic Radio and Network Planning of IoT Sensor Networks
Authors: Kanaris Loizos , Sergiou Charalampos , Kokkinis Akis , Pafitis Aris , Antoniou Nikos , Stavrou Stavros
Published: July 2019

Planning and deploying a functional large scale Wireless Sensor Network (WSN) or a Network of Internet of Things (IoTs) is a challenging task, especially in complex urban environments. A main network design bottleneck is the existence and/or correct usage of appropriate cross layer simulators that can generate realistic results for the scenario of interest. Existing network simulators tend to overlook the complexity of the physical radio propagation layer and consequently do not realistically simulate the main radio propagation conditions that take place in urban or suburban environments, thus passing inaccurate results between Open Systems Interconnection (OSI) layers. This work demonstrates through simulations and measurements that, by correctly passing physical information to higher layers, the overall simulation process produces more accurate results at the network layer. It is demonstrated that the resulting simulation methodology can be utilized to accomplish realistic wireless planning and performance analysis of the deployed nodes, with results that are very close to those of real test-beds, or actual WSN deployments.
Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging
Authors: Egarievwe Stephen U. , Roy Utpal N. , Goree Carmella A. , Harrison Benicia A. , Jones Jeanette , James Ralph B.
Published: July 2019

Cadmium zinc telluride selenide (Cd1−xZnxTe1−ySey or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between −35 V and −200 V. The results showed an average of 25% improvement in the detector’s energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10−3 cm2/V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors.