bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Static Stiffness after Motion on a Three-Axis CNC Milling Table
Authors: Stejskal Tomáš , Svetlík Jozef , Dovica Miroslav , Demeč Peter , Kráľ Ján
Published: December 2017

This paper deals with a modified methodology for measuring the static stiffness of the machine tool. Inspiration to modify the commonly used expanded method of static stiffness measurement resulted from considerably different experimentally measured static stiffness values in the simulated process of load application under laboratory conditions compared to the standard method. An important takeaway from the measurements is that the measured static stiffness of the table depends greatly on the previous work performed thereon and on the method of the load application onto the table. This modified view of the static stiffness of the machine can have an impact on the increased emphasis on eliminating the phenomena related thereto. It is applicable in engineering practice, in particular in the field of machine tool design, where it will ensure higher machining precision under comparable conditions. In the experiments performed, deformations and displacements were measured with a laser interferometer.
Optimal Steady-State Range Prediction Filter for Tracking with LFM Waveforms
Authors: Saho Kenshi
Published: December 2017

This communication proposes a gain design method of an α - β filter with linear frequency-modulated (LFM) waveforms to achieve optimal range prediction (tracking) of maneuvering targets in steady-state. First, a steady-state root-mean-square (RMS) prediction error, called an RMS-index, is analytically derived for a constant-acceleration target. Next, a design method of the optimal gains that minimizes the derived RMS-index is proposed. Numerical analyses demonstrate the effectiveness of the proposed method, as well as producing a performance improvement over the conventional Kalman filter-based design method. Moreover, the theoretical relationship between range tracking performance and a coefficient for range-Doppler coupling of LFM waveforms is clarified. Numerical simulations using the proposed method demonstrate LFM radar tracking of maneuvering targets and prove the method’s effectiveness.
A Game Player Expertise Level Classification System Using Electroencephalography (EEG)
Authors: Anwar Syed , Saeed Sanay , Majid Muhammad , Usman Saeeda , Mehmood Chaudhry , Liu Wei
Published: December 2017

The success and wider adaptability of smart phones has given a new dimension to the gaming industry. Due to the wide spectrum of video games, the success of a particular game depends on how efficiently it is able to capture the end users’ attention. This leads to the need to analyse the cognitive aspects of the end user, that is the game player, during game play. A direct window to see how an end user responds to a stimuli is to look at their brain activity. In this study, electroencephalography (EEG) is used to record human brain activity during game play. A commercially available EEG headset is used for this purpose giving fourteen channels of recorded EEG brain activity. The aim is to classify a player as expert or novice using the brain activity as the player indulges in the game play. Three different machine learning classifiers have been used to train and test the system. Among the classifiers, naive Bayes has outperformed others with an accuracy of 88 % , when data from all fourteen EEG channels are used. Furthermore, the activity observed on electrodes is statistically analysed and mapped for brain visualizations. The analysis has shown that out of the available fourteen channels, only four channels in the frontal and occipital brain regions show significant activity. Features of these four channels are then used, and the performance parameters of the four-channel classification are compared to the results of the fourteen-channel classification. It has been observed that support vector machine and the naive Bayes give good classification accuracy and processing time, well suited for real-time applications.
Facile Synthesis of Two-Dimensional Porous MgCo2O4 Nanosheets as Anode for Lithium-Ion Batteries
Authors: Wang Fei , Liu Yong , Zhao Yuanfang , Wang Yue , Wang Zhijie , Zhang Wanhong , Ren Fengzhang
Published: December 2017

Lithium-ion batteries (LIBs) have drawn considerable attention due to their high energy density and good cycling stability. As a transition-metal oxide, MgCo2O4 (MCO) is a promising candidate for energy storage applications because of its low-cost and environmental characteristics. Here, MCO porous nanosheets have been successfully synthesized by a microwave-assisted liquid phase method followed by an annealing procedure. As a result, MCO annealed at 600 °C exhibited optimal rate and cycling performances for Lithium storage application. Specifically, when tested as anode materials for Lithium ion batteries, MCO porous nanosheets delivered a high specific capacity of 1173.8 mAh g−1 at 200 mA g−1, and the specific capacity reached 1130.1 mAh g−1 after 100 cycles at 200 mA g−1, achieving 96.3% for the retention rate. The excellent electrochemical performances are mainly attributed to the monolayer porous nanosheet, which provides short transport paths for Li ions and electrons. Results demonstrated that the MCO porous nanosheets are promising electrode materials for Lithium ion batteries applications.
Estimate of Passive Time Reversal Communication Performance in Shallow Water
Authors: Kim Sunhyo , Son Su-Uk , Kim Hyeonsu , Choi Kang-Hoon , Choi Jee
Published: December 2017

Time reversal processes have been used to improve communication performance in the severe underwater communication environment characterized by significant multipath channels by reducing inter-symbol interference and increasing signal-to-noise ratio. In general, the performance of the time reversal is strongly related to the behavior of the q -function, which is estimated by a sum of the autocorrelation of the channel impulse response for each channel in the receiver array. The q -function depends on the complexity of the communication channel, the number of channel elements and their spacing. A q -function with a high side-lobe level and a main-lobe width wider than the symbol duration creates a residual ISI (inter-symbol interference), which makes communication difficult even after time reversal is applied. In this paper, we propose a new parameter, E q , to describe the performance of time reversal communication. E q is an estimate of how much of the q -function lies within one symbol duration. The values of E q were estimated using communication data acquired at two different sites: one in which the sound speed ratio of sediment to water was less than unity and one where the ratio was higher than unity. Finally, the parameter E q was compared to the bit error rate and the output signal-to-noise ratio obtained after the time reversal operation. The results show that these parameters are strongly correlated to the parameter E q .
Message Collision Avoidance Protocols for Detecting Stray Nodes in a Scuba Diving Group Using Ultrasonic Multi-Hop Message Communication
Authors: Kaido Shinya , Takami Kazumasa
Published: December 2017

Recent years have seen a growing interest in underwater communication and some progress has been made in this area. However, underwater communication is still immature compared with terrestrial communication. A prime reason for this is that the underwater environment is intrinsically not suitable for propagation of electric waves. Instead, ultrasonic waves are mainly used for underwater communication. Since ultrasonic waves cannot provide sufficient communication speed or capacity, they cannot use existing network technologies, which assume use of radio waves. In particular, communication in shallow water is still an uncharted territory. Few communication technologies are employed in environments where people enjoy scuba diving. This paper addresses problems faced by recreational scuba divers. It proposes constructing an ad hoc mesh-shaped network between divers within a group and use ultrasonic waves as transmission media in order to enable the detection of a stray diver. It also proposes a communication protocol in which messages are relayed in multiple hops, and a message collision avoidance method, which is intended to reduce the rate of packet loss caused by message propagation delay. We have implemented the proposed methods in a network simulator, and compared them with an existing communication method that has no message collision avoidance function, in terms of the packet loss rate, the stray driver detection rate, and the rate of the ability to communicate in multiple hops.
Comparative Study on KNN and SVM Based Weather Classification Models for Day Ahead Short Term Solar PV Power Forecasting
Authors: Wang Fei , Zhen Zhao , Wang Bo , Mi Zengqiang
Published: December 2017

Accurate solar photovoltaic (PV) power forecasting is an essential tool for mitigating the negative effects caused by the uncertainty of PV output power in systems with high penetration levels of solar PV generation. Weather classification based modeling is an effective way to increase the accuracy of day-ahead short-term (DAST) solar PV power forecasting because PV output power is strongly dependent on the specific weather conditions in a given time period. However, the accuracy of daily weather classification relies on both the applied classifiers and the training data. This paper aims to reveal how these two factors impact the classification performance and to delineate the relation between classification accuracy and sample dataset scale. Two commonly used classification methods, K-nearest neighbors (KNN) and support vector machines (SVM) are applied to classify the daily local weather types for DAST solar PV power forecasting using the operation data from a grid-connected PV plant in Hohhot, Inner Mongolia, China. We assessed the performance of SVM and KNN approaches, and then investigated the influences of sample scale, the number of categories, and the data distribution in different categories on the daily weather classification results. The simulation results illustrate that SVM performs well with small sample scale, while KNN is more sensitive to the length of the training dataset and can achieve higher accuracy than SVM with sufficient samples.
Robust Control Examples Applied to a Wind Turbine Simulated Model
Authors: Simani Silvio , Castaldi Paolo
Published: December 2017

Wind turbine plants are complex dynamic and uncertain processes driven by stochastic inputs and disturbances, as well as different loads represented by gyroscopic, centrifugal and gravitational forces. Moreover, as their aerodynamic models are nonlinear, both modeling and control become challenging problems. On the one hand, high-fidelity simulators should contain different parameters and variables in order to accurately describe the main dynamic system behavior. Therefore, the development of modeling and control for wind turbine systems should consider these complexity aspects. On the other hand, these control solutions have to include the main wind turbine dynamic characteristics without becoming too complicated. The main point of this paper is thus to provide two practical examples of the development of robust control strategies when applied to a simulated wind turbine plant. Extended simulations with the wind turbine benchmark model and the Monte Carlo tool represent the instruments for assessing the robustness and reliability aspects of the developed control methodologies when the model-reality mismatch and measurement errors are also considered. Advantages and drawbacks of these regulation methods are also highlighted with respect to different control strategies via proper performance metrics.
Design, Implementation, and Field Testing of a Privacy-Aware Compliance Tracking System for Bedside Care in Nursing Homes
Authors: Zhao Wenbing , Wu Qing , Reinthal Ann , Zhang Nian
Published: December 2017

Lower back musculoskeletal disorders are pervasive in workplaces. In the United States alone, the total cost of such injuries exceed $100 billion a year. The lower-back injury rate in the healthcare sector is one of the highest among all industry sectors. A main risk factor for lower-back injuries is the use of improper body mechanics when doing lifting and pulling activities. In healthcare venues, nursing homes in particular, nursing assistants are on the front line to take care of patients. Even in places where ceiling-mounted lifting equipment is installed, they are still required to handle the patient for bedside care, such as sliding the sling underneath the patient, scooping up the patient, putting on compression socks, etc. To help nursing assistants get into the habit of using proper body mechanics, we designed and implemented a privacy-aware compliance tracking system (PACTS). PACTS can track a nursing assistant for possible violation of proper body mechanics while doing bedside care and provide realtime feedback via a smart wearable device such as a smart watch worn by the nursing assistant. The system was deployed in a local nursing home for an 80-day field study in six rooms with seven participating nursing assistants. The test exposed several issues with the original design of the system. The primary issue is how to balance the privacy requirement and the usability of the system. Over-emphasizing the former would negatively impact the latter. This issue is partially resolved with a leasing mechanism where the system would automatically register a nursing assistant within the lease period once she or he has manually registered with the system.
A Fuzzy Trade-Off Ranking Method for Multi-Criteria Decision-Making
Authors: Jaini Nor , Utyuzhnikov Sergey
Published: December 2017

The aim of this paper is to present a trade-off ranking method in a fuzzy multi-criteria decision-making environment. The triangular fuzzy numbers are used to represent the imprecise numerical quantities in the criteria values of each alternative and the weight of each criterion. A fuzzy trade-off ranking method is developed to rank alternatives in the fuzzy multi-criteria decision-making problem with conflicting criteria. The trade-off ranking method tackles this type of multi-criteria problems by giving the least compromise solution as the best option. The proposed method for the fuzzy decision-making problems is compared against two other fuzzy decision-making approaches, fuzzy Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) and fuzzy VlseKriterijuska Optimizacija I Komoromisno Resenje (VIKOR), used for ranking alternatives.
Incomplete Penetrance and Variable Expressivity: Hallmarks in Channelopathies Associated with Sudden Cardiac Death
Authors: Coll Monica , Pérez-Serra Alexandra , Mates Jesus , Del Olmo Bernat , Puigmulé Marta , Fernandez-Falgueras Anna , Iglesias Anna , Picó Ferran , Lopez Laura , Brugada Ramon , Campuzano Oscar
Published: December 2017

Sudden cardiac death is defined as an unexpected decease of cardiac origin. In individuals under 35 years old, most of these deaths are due to familial arrhythmogenic syndromes of genetic origin, also known as channelopathies. These familial cardiac syndromes commonly follow an autosomal dominant pattern of inheritance. Diagnosis, however, can be difficult, mainly due to incomplete penetrance and variable expressivity, which are hallmarks in these syndromes. The clinical manifestation of these diseases can range from asymptomatic to syncope but sudden death can sometimes be the first symptom of disease. Early identification of at-risk individuals is crucial to prevent a lethal episode. In this review, we will focus on the genetic basis of channelopathies and the effect of genetic and non-genetic modifiers on their phenotypes.
An FT-Raman, FT-IR, and Quantum Chemical Investigation of Stanozolol and Oxandrolone
Authors: Lemma Tibebe , De Barros Souza Fabiano , Tellez Soto Claudio , Martin Airton
Published: December 2017

We have studied the Fourier Transform Infrared (FT-IR) and the Fourier transform Raman (FT-Raman) spectra of stanozolol and oxandrolone, and we have performed quantum chemical calculations based on the density functional theory (DFT) with a B3LYP/6-31G (d, p) level of theory. The FT-IR and FT-Raman spectra were collected in a solid phase. The consistency between the calculated and experimental FT-IR and FT-Raman data indicates that the B3LYP/6-31G (d, p) can generate reliable geometry and related properties of the title compounds. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compounds, which show agreement with the observed spectra.
A Prospective Birth Cohort Study on Maternal Cholesterol Levels and Offspring Attention Deficit Hyperactivity Disorder: New Insight on Sex Differences
Authors: Ji Yuelong , Riley Anne , Lee Li-Ching , Volk Heather , Hong Xiumei , Wang Guoying , Angomas Rayris , Stivers Tom , Wahl Anastacia , Ji Hongkai , Bartell Tami , Burd Irina , Paige David , Fallin Margaret , Zuckerman Barry , Wang Xiaobin
Published: December 2017

Growing evidence suggests that maternal cholesterol levels are important in the offspring’s brain growth and development. Previous studies on cholesterols and brain functions were mostly in adults. We sought to examine the prospective association between maternal cholesterol levels and the risk of attention deficit hyperactivity disorder (ADHD) in the offspring. We analyzed data from the Boston Birth Cohort, enrolled at birth and followed from birth up to age 15 years. The final analyses included 1479 mother-infant pairs: 303 children with ADHD, and 1176 neurotypical children without clinician-diagnosed neurodevelopmental disorders. The median age of the first diagnosis of ADHD was seven years. The multiple logistic regression results showed that a low maternal high-density lipoprotein level (≤60 mg/dL) was associated with an increased risk of ADHD, compared to a higher maternal high-density lipoprotein level, after adjusting for pertinent covariables. A “J” shaped relationship was observed between triglycerides and ADHD risk. The associations with ADHD for maternal high-density lipoprotein and triglycerides were more pronounced among boys. The findings based on this predominantly urban low-income minority birth cohort raise a new mechanistic perspective for understanding the origins of ADHD and the gender differences and future targets in the prevention of ADHD.
Emotional Encoding Context Leads to Memory Bias in Individuals with High Anxiety
Authors: Lee Christopher , Fernandes Myra
Published: December 2017

We investigated whether anxious individuals, who adopt an inherently negative mindset, demonstrate a particularly salient memory bias for words tainted by negative contexts. To this end, sequentially presented target words, overlayed onto negative or neutral pictures, were studied in separate blocks (within-subjects) using a deep or shallow encoding instruction (between-subjects). Following study, in Test 1, participants completed separate recognition test blocks for the words overlayed onto the negative and the neutral contexts. Following this, in Test 2, participants completed a recognition test for the foils from each Test 1 block. We found a significant three-way interaction on Test 2, such that individuals with high anxiety who initially studied target words using a shallow encoding instruction, demonstrated significantly elevated memory for foils that were contained within the negative Test 1 block. Results show that during retrieval (Test 1), participants re-entered the mode of processing (negative or neutral) engaged at encoding, tainting the encoding of foils with that same mode of processing. The findings suggest that individuals with high relative to low anxiety, adopt a particularly salient negative retrieval mode, and this creates a downstream bias in encoding and subsequent retrieval of otherwise neutral information.
Synthesis of Hybrid Silica-Carbon Tubular Structures by Chemical Vapor Deposition with Methane or Ethene
Authors: Sepulveda Victor , López Betty
Published: December 2017

Silica microtube and carbon nanotube hybrid structures have been synthesized by catalytic chemical vapor deposition using either methane or ethene as the carbon source, and cobalt-grafted or impregnated silica tubes (200–800 nm) as catalyst. The cobalt-grafted catalyst shows a high resistance to reduction (>1000 °C) and selectivity to single-wall carbon nanotubes (SWCNT). While ethene deposition produces more carbonaceous material, methane experiments show higher selectivity for SWCNT. After removing the silica with an excess of HF, the carbon nanostructure endured, resulting in a coaxial carbon nanostructure. The novel hybrid nanostructures obtained consist of a submicron-sized tube, with walls that are formed by a succession of carbon/silica/carbon layers to which multiwall (20–25 nm) and/or single-wall (0.6–2.0 nm) carbon nanotubes are attached. This synthesis approach combines the mechanical properties of carbon nanotubes and the thermal properties of silica tubes into a synergetic nanostructured material, opening further possibilities for polymer reinforcement and potential applications in catalysis.
Polymeric Antimicrobial Coatings Based on Quaternary Ammonium Compounds
Authors: Druvari Denisa , Koromilas Nikos , Bekiari Vlasoula , Bokias Georgios , Kallitsis Joannis
Published: December 2017

Biocidal coatings that are based on quaternized ammonium copolymers were developed after blending and crosslinking and studied as a function of the ratio of reactive groups and the type of biocidal groups, after curing at room temperature or 120 °C. For this purpose, two series of copolymers with complementary reactive groups, poly(4-vinylbenzyl chloride-co-acrylic acid), P(VBC-co-AAx), and poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate), P(SSNa-co-GMAx), were synthesized via free radical copolymerization and further modified resulting in covalently bound (4-vinylbenzyl dimethylhexadecylammonium chloride, VBCHAM) and electrostatically attached (hexadecyltrimethylammonium 4-styrene sulfonate, SSAmC16) units. The crosslinking reaction between the carboxylic group of acrylic acid (AA) and the epoxide group of glycidyl methacrylate (GMA) of these copolymers led to the stabilization of the coatings through reactive blending. The so developed coatings were cured at room temperature and 120 °C, and then immersed in ultra-pure water and aqueous NaCl solutions at various concentrations for a time period up to three months. Visual inspection of the integrity of the materials coated onto glass slides, gravimetry, scanning electron microscopy (SEM) characterization, as well as the determination of total organic carbon (TOC) and total nitrogen (TN) of the solutions, were used to investigate the parameters affecting the release of the materials from the coatings based on these systems. The results revealed that curing temperature, complementary reactive groups’ content, and type of antimicrobial species control the release levels and the nature of releasable species of these environmentally-friendly antimicrobial coatings.
Plastic Deformation Induced by Nanoindentation Test Applied on ZrN/Si3N4 Multilayer Coatings
Authors: Wu Zhengtao , Zhong Xing , Liu Cihai , Wang Zhoucheng , Dai Wei , Wang Qimin
Published: December 2017

ZrN/Si3N4 multilayer coating that alternates with either nanocrystalline ZrN or amorphous Si3N4 interlayers was fabricated by reactively magnetron sputtering in an Ar-N2 mixture atmosphere. The thicknesses of the nanocrystalline ZrN and the amorphous Si3N4 interlayers are ~12.5 and 2.5 nm, respectively. The ZrN/Si3N4 coating exhibits a promoted hardness of 28.6 ± 1.2 GPa when compared to the binary ZrN. Microstructure evolution just underneath the nanoindentation impression of the ZrN/Si3N4 multilayer coating has been investigated. The result indicates that both ZrN nanograin rotations and plastic flow of the Si3N4 interlayers contribute to the permanent deformation of the multilayer coating induced by the nanoindentation. In addition, the introduction of the a-Si3N4 interlayers hinders both the initiation and propagation of microcracks when the multilayer coating was applied to the scratch test. The propagation deflection of the microcracks was observed attributed to the heterogenous interface, which produces the hardness promotion of the multilayer coating eventually.
Cutaneous Permeation and Penetration of Sunscreens: Formulation Strategies and In Vitro Methods
Authors: Tampucci Silvia , Burgalassi Susi , Chetoni Patrizia , Monti Daniela
Published: December 2017

Sunscreens are the most common products used for skin protection against the harmful effects of ultraviolet radiation. However, as frequent application is recommended, the use of large amount of sunscreens could reflect in possible systemic absorption and since these preparations are often applied on large skin areas, even low penetration rates can cause a significant amount of sunscreen to enter the body. An ideal sunscreen should have a high substantivity and should neither penetrate the viable epidermis, the dermis and the systemic circulation, nor in hair follicle. The research of methods to assess the degree of penetration of solar filters into the skin is nowadays even more important than in the past, due to the widespread use of nanomaterials and the new discoveries in cosmetic formulation technology. In the present paper, different in vitro studies, published in the last five years, have been reviewed, in order to focus the attention on the different methodological approaches employed to effectively assess the skin permeation and retention of sunscreens.
Effects of Crystal Orientation on the Crack Propagation of Sapphire by Sequential Indentation Testing
Authors: Wang Ningchang , Jiang Feng , Xu Xipeng , Lu Xizhao
Published: December 2017

Single-crystal sapphire (α-Al2O3) is a hard and brittle material. Due to its highly crystalline nature, the fracture behavior of sapphire is strongly related to its crystal structure, and understanding the effects of crystal structure on the crack propagation of sapphire is essential for the successful application of this important material (e.g., as wafers in the electronics industry). In the present work, crack propagation that is induced by sequential indentation was investigated on the A-plane and C-plane of sapphire using a Vickers indenter on a micrometer scale. It was found that increasing indentation depth obviously increases the rate of crack propagation on the A-plane, but this effect is not so obvious on the C-plane because of the different slip systems induced by indentation on the different crystal planes of sapphire. Moreover, some parallel linear traces along the A-plane, which fracture with increasing indentation depth, are observed from the residual indentation on the A-plane. The fracture toughness of both A-plane and C-plane sapphire is smaller after indentation testing than that obtained using conventional testing methods. The subsurface damage was detected by transmission electron microscopy (TEM).
Liquid Crystal Ordering of Four-Base-Long DNA Oligomers with Both G–C and A–T Pairing
Authors: Fraccia Tommaso P. , Smith Gregory P. , Clark Noel A. , Bellini Tommaso
Published: December 2017

We report the liquid crystal (LC) ordering in an aqueous solution of four-base-long DNA oligomers 5′-GCTA-3′. In such systems, the formation of the chiral nematic (N*) LC phase is the result of a continuous self-assembly process in which double helix stability is achieved only through linear chaining of multiple DNA strands. The thermal stability of the aggregates and their LC phase diagram have been experimentally investigated, quantitatively interpreted with theoretical models and compared with recent results on four-base sequences with only G–C or only A–T pairing motifs. N* phase is found at GCTA concentration, cDNA, between 240 and 480 mg/mL and at temperature T < 30 °C. The twist of the nematic director is found to be left-handed with pitch (p) in the optical range, increasing with cDNA and decreasing with T.
Structural Basis for the Influence of A1, 5A, and W51W57 Mutations on the Conductivity of the Geobacter sulfurreducens Pili
Authors: Shu Chuanjun , Xiao Ke , Sun Xiao
Published: December 2017

The metallic-like conductivity of the Geobacter sulfurreducens pilus and higher conductivity of its mutants reflected that biological synthesis can be utilized to improve the properties of electrically conductive pili. However, the structural basis for diverse conductivities of nanowires remains uncertain. Here, the impacts of point mutations on the flexibility and stability of pilins were investigated based on molecular dynamics simulations. Structures of the G. sulfurreducens pilus and its mutants were constructed by Rosetta. Details of the structure (i.e., electrostatic properties, helical parameters, residue interaction network, distances between amino acids, and salt bridges) were analyzed by PDB2PQR, Rosetta, RING, PyMOL, and VMD, respectively. Changes in stability, flexibility, residue interaction, and electrostatic properties of subunits directly caused wild-type pilin and its mutants assemble different structures of G. sulfurreducens pili. By comparing the structures of pili with different conductivities, the mechanism by which the G. sulfurreducens pilus transfers electron along pili was attributed, at least in part, to the density of aromatic rings, the distances between neighboring aromatic rings, and the local electrostatic environment around aromatic contacts. These results provide new insight into the potential for the biological synthesis of highly electrically conductive, nontoxic nanowires.
Hepatitis B Virus Genotype C is Predominant in Myanmar
Authors: Nwe Win Nan , Nakamoto Shingo , Myint Sein Myint , Moriyama Mitsuhiko , Kanda Tatsuo , Shirasawa Hiroshi
Published: December 2017

Myanmar is adjacent to India, Bangladesh, Thailand, Laos and China. In Myanmar, the prevalence of hepatitis B virus (HBV) infections is 6.5% and accounts for 60% of hepatocellular carcinoma. HBV has nine genotypes that have been identified by molecular genetic analysis. HBV genotypes are associated with several clinical features. We reviewed the prevalence of HBV genotypes in Myanmar and neighboring countries. We also reviewed HBV genotypes in refugees from Myanmar. HBV subgenotype C1 is predominant in Myanmar. As HBV genotype C is associated with hepatocellular carcinoma (HCC), it is important to screen for cirrhosis and HCC and to prevent their development in HBV-infected individuals of Myanmar.
Remarks on the Maximum Entropy Principle with Application to the Maximum Entropy Theory of Ecology
Authors: Favretti Marco
Published: December 2017

In the first part of the paper we work out the consequences of the fact that Jaynes’ Maximum Entropy Principle, when translated in mathematical terms, is a constrained extremum problem for an entropy function H ( p ) expressing the uncertainty associated with the probability distribution p. Consequently, if two observers use different independent variables p or g ( p ) , the associated entropy functions have to be defined accordingly and they are different in the general case. In the second part we apply our findings to an analysis of the foundations of the Maximum Entropy Theory of Ecology (M.E.T.E.) a purely statistical model of an ecological community. Since the theory has received considerable attention by the scientific community, we hope to give a useful contribution to the same community by showing that the procedure of application of MEP, in the light of the theory developed in the first part, suffers from some incongruences. We exhibit an alternative formulation which is free from these limitations and that gives different results.
Magnet Shape Optimization of Two-Layer Spoke-Type Axial Flux Interior Permanent Magnet Machines
Authors: Chai Feng , Bi Yunlong , Pei Yulong
Published: December 2017

In this paper, the two-layer spoke-type (TLST) axial flux interior permanent magnet (AFIPM) machine is proposed. Simple flux barriers are added to optimize the air gap flux density, in which way there is no need to change the surface of the rotor. The optimization principle is revealed and the advantages of the TLST AFIPM machine compared with the spoke-type (ST) AFIPM machine are clarified. An optimization design process based on magnetic equivalent circuit combined with idealized and improved air gap flux density waveform is proposed, in which way the calculation time is saved by avoiding an excess of finite element method (FEM) simulations. Finally, 3D FEM simulation is adopted to verify the optimization results.
Improving Transient Response of Power Converter in a Stand-Alone Microgrid Using Virtual Synchronous Generator
Authors: Nguyen Cao-Khang , Nguyen Thai-Thanh , Yoo Hyeong-Jun , Kim Hak-Man
Published: December 2017

Multiple power converters based on the droop controllers have been used widely in the microgrid (MG) system. However, owing to the different response time among several types of power converters such as grid-feeding and grid-forming converters, low frequency oscillation occurs with high overshoot in the transient state. This paper proposes a novel control strategy based on the virtual synchronous generator (VSG) for improving transient response of parallel power converters during large disturbance in the stand-alone microgrid. The proposed VSG control, which inherits the transient state characteristic of the synchronous generator, can provide inertia virtually to the system. The transient response of voltage and frequency is improved, while the total system inertia response is compensated. Thus, the system stability can be enhanced by using the proposed VSG control. Additionally, the small signal analysis of the conventional VSG controller and the proposed VSG controller are carried out to show the effectiveness of the proposed VSG controller. The derivation of frequency, which is used to evaluate the inertia support of the VSG controller to the MG system, is discussed. The simulation result demonstrates that the overshoot of the transient response can be reduced, and the system stability is improved when the proposed VSG controller is applied. The MG system based on the real-time simulator OP5600 (OPAL-RT Technologies, Montreal, QC, Canada) is carried out to verify the feasibility of the proposed VSG controller.
Research on a Novel Hydraulic/Electric Synergy Bus
Authors: Zhao Kegang , Liang Zhihao , Huang Yanjun , Wang Hong , Khajepour Amir , Zhen Yuke
Published: December 2017

In recent years, increasing concerns regarding environmental pollution and requirements for lower fossil fuel consumption have increased interest in alternative hybrid powertrains. As a result, this paper presents a novel hydraulic/electric synergy powertrain with multiple working modes. The three energy sources (i.e., engine, battery, and hydraulic accumulator) in this configuration are regulated by a dual planetary gear set to achieve optimal performances. This paper selects the component sizes of a hybrid electric vehicle (HEV), a hydraulic hybrid vehicle (HHV), and a hydraulic/electric synergy vehicle (HESV), based on the dynamic performance of a target vehicle (TV). In addition, this paper develops the forward simulation models of the four aforementioned vehicles in the MATLAB/Simulink/Driveline platform, in which the fuel economy simulations are carried out in relation to the Chinese urban bus cycle. The simulation results show that the fuel consumption of the three hybrid vehicles is similar, but much better than, that of the TV. Finally, based on the operating cost calculations over a five-year working period, the lowest cost ranges of the three hybrid vehicles are determined, which provides a method for choosing the optimal hybrid scheme.
Comparative Modeling of a Parabolic Trough Collectors Solar Power Plant with MARS Models
Authors: Rogada Jose , Barcia Lourdes , Martinez Juan , Menendez Mario , De Cos Juez Francisco
Published: December 2017

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.
Verification of Energy Reduction Effect through Control Optimization of Supply Air Temperature in VRF-OAP System
Authors: Lee Je , Yoon Hyun , Im Piljae , Song Young-hak
Published: December 2017

This paper developed an algorithm that controls the supply air temperature in the variable refrigerant flow (VRF), outdoor air processing unit (OAP) system, according to indoor and outdoor temperature and humidity, and verified the effects after applying the algorithm to real buildings. The VRF-OAP system refers to a heating, ventilation, and air conditioning (HVAC) system to complement a ventilation function, which is not provided in the VRF system. It is a system that supplies air indoors by heat treatment of outdoor air through the OAP, as a number of indoor units and OAPs are connected to the outdoor unit in the VRF system simultaneously. This paper conducted experiments with regard to changes in efficiency and the cooling capabilities of each unit and system according to supply air temperature in the OAP using a multicalorimeter. Based on these results, an algorithm that controlled the temperature of the supply air in the OAP was developed considering indoor and outdoor temperatures and humidity. The algorithm was applied in the test building to verify the effects of energy reduction and the effects on indoor temperature and humidity. Loads were changed by adjusting the number of conditioned rooms to verify the effect of the algorithm according to various load conditions. In the field test results, the energy reduction effect was approximately 15–17% at a 100% load, and 4–20% at a 75% load. However, no significant effects were shown at a 50% load. The indoor temperature and humidity reached a comfortable level.
Organosolv Fractionation of Softwood Biomass for Biofuel and Biorefinery Applications
Authors: Nitsos Christos , Rova Ulrika , Christakopoulos Paul
Published: December 2017

Softwoods represent a significant fraction of the available lignocellulosic biomass for conversion into a variety of bio-based products. Its inherent recalcitrance, however, makes its successful utilization an ongoing challenge. In the current work the research efforts for the fractionation and utilization of softwood biomass with the organosolv process are reviewed. A short introduction into the specific challenges of softwood utilization, the development of the biorefinery concept, as well as the initial efforts for the development of organosolv as a pulping method is also provided for better understanding of the related research framework. The effect of organosolv pretreatment at various conditions, in the fractionation efficiency of wood components, enzymatic hydrolysis and bioethanol production yields is then discussed. Specific attention is given in the effect of the pretreated biomass properties such as residual lignin on enzymatic hydrolysis. Finally, the valorization of organosolv lignin via the production of biofuels, chemicals, and materials is also described.
Particle (Soot) Pollution in Port Harcourt Rivers State, Nigeria—Double Air Pollution Burden? Understanding and Tackling Potential Environmental Public Health Impacts
Authors: Yakubu Okhumode
Published: December 2017

Residents of Port Harcourt in Rivers State, Nigeria, and its environs have since the last quarter of 2016 been experiencing adverse environmental impacts of particle (soot) pollution. This “double air pollution burden”—the unresolved prevailing widespread air pollution and the “added” emergence of particle pollution considered an environmental health threat, led to protests against government inaction in some parts of the state. In February 2017, several months following the onset of the pollution, the government declared an Emergency, and set up a Task Force to investigate and find a solution to the problem. Global research suggests that particle pollution correlates positively with a range of morbidities and an increased risk of mortality among exposed populations. This underscores the need for rigorous implementation of existing environmental legislations established to protect the environment and public health. Nigeria’s rapid response to the 2014–2015 Ebola Virus Disease (EVD) and successful prevention of its spread provides some lessons for addressing such environmental health emergencies—strategic action, including effective environmental risk communication, environmental audit, and monitoring is key. Epidemiological studies of the affected population is imperative. A concerted effort by the Rivers State Ministries of Environment and Health, as well as academia and private organizations is required. Public service campaign in terms of government providing up to date information on the existing situation is required.
Responses of Tree Seedlings near the Alpine Treeline to Delayed Snowmelt and Reduced Sky Exposure
Authors: Bader Maaike , Loranger Hannah , Zotz Gerhard , Mendieta-Leiva Glenda
Published: December 2017

Earlier snowmelt changes spring stress exposure and growing-season length, possibly causing shifts in plant species dominance. If such shifts involve trees, this may lead to changes in treeline position. We hypothesized that earlier snowmelt would negatively affect the performance of tree seedlings near the treeline due to higher spring stress levels, but less so if seedlings were protected from the main stress factors of night frosts and excess solar radiation. We exposed seedlings of five European treeline tree species: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata, and Sorbus aucuparia to two snow-cover treatments (early and late melting, with about two weeks difference) combined with reduced sky exposure during the day (shading) or night (night warming), repeated in two years, at a site about 200 m below the regional treeline elevation. Physiological stress levels (as indicated by lower Fv/Fm) in the first weeks after emergence from snow were higher in early-emerging seedlings. As expected, shade reduced stress, but contrary to expectation, night warming did not. However, early- and late-emerging seedlings did not differ overall in their growth or survival, and the interaction with shading was inconsistent between years. Overall, shading had the strongest effect, decreasing stress levels and mortality (in the early-emerging seedlings only), but also growth. A two-week difference in snow-cover duration did not strongly affect the seedlings, although even smaller differences have been shown to affect productivity in alpine and arctic tundra vegetation. Still, snowmelt timing cannot be discarded as important for regeneration in subalpine conditions, because (1) it is likely more critical in very snow-rich or snow-poor mountains or landscape positions; and (2) it can change (sub)alpine vegetation phenology and productivity, thereby affecting plant interactions, an aspect that should be considered in future studies.
Comparison of Wood Quality of Douglas Fir and Spruce from Afforested Agricultural Land and Permanent Forest Land in the Czech Republic
Authors: Zeidler Aleš , Borůvka Vlastimil , Schönfelder Ondřej
Published: December 2017

This study compares the quality of wood from two distinct sites in the Czech Republic—from former afforested agricultural land and forest land. We compared the properties of Norway spruce wood (Picea abies Karst.) and Scots pine wood (Pinus sylvestris L.), the most important domestic tree species, to Douglas fir (Pseudotsuga menziesii (Mirbel) Franco), a North American tree species and a potential substitute for the domestic spruce. Wood density, modulus of elasticity (MOE), modulus of rupture (MOR) and impact bending strength were the properties tested that were used for comparing tree species. Without taking into consideration the site, the highest density values from the tested tree species were obtained for Douglas fir (0.568 g·cm−3), followed by the pine (0.508 g·cm−3) and the spruce (0.463 g·cm−3). The Douglas fir also dominated in the remaining assessed properties, whilst the influence of site was not confirmed, with the exception of MOE and MOR, and only for the Douglas fir wood, wherein higher values were obtained for forest land. In terms assessed Douglas fir properties, it exceeds the domestic softwoods and represents a possible suitable replacement for them. The site only plays a role in terms of the Douglas fir, and only for certain properties.
Effects of Warming and Precipitation Manipulation on Fine Root Dynamics of Pinus densiflora Sieb. et Zucc. Seedlings
Authors: Han Seung , Kim Seongjun , Li Guanlin , Chang Hanna , Yun Soon , An Jiae , Son Yowhan
Published: December 2017

Air warming (TC: control; TW: +3 °C) and precipitation manipulation (PC: control; PD: −30%; PI: +30%) were established to examine effects of these treatments on fine root production (FRP), fine root mortality (FRM), and total root (coarse and fine root) biomass in 33- to 59-month-old Pinus densiflora Sieb. et Zucc. seedlings for two years. We hypothesized that warming and altered precipitation would affect the growth, death, and biomass of fine roots by changing soil temperature and soil water availability. Mean annual FRP and total root biomass were significantly altered by only precipitation manipulation: they were 29.3% (during the two-year period) and 69.0% (after the entire two years) higher, respectively, in PD plots than in PC plots, respectively. In contrast, only warming had a significant effect on mean annual FRM, being 13.2% lower in TW plots than TC plots during the two-year period. Meanwhile, fine root biomass was affected negatively and simultaneously by both soil temperature and soil moisture. It seemed that fine root dynamics have changed so that they maintain their systems in response to the altered soil temperature and moisture. The current study adds significant knowledge for understanding the fine root dynamics of P. densiflora seedlings under altered temperature and precipitation regimes.