bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the solar twin 18 Scorpii
Authors: Bazot M. , Creevey O. , Christensen-Dalsgaard J. , Meléndez J.
Published: September 2018

Context.Solar twins are objects of great interest in that they allow us to understand better how stellar evolution and structure are affected by variations of the stellar mass, age and chemical composition in the vicinity of the commonly accepted solar values.

Aims.We aim to use the existing spectrophotometric, interferometric and asteroseismic data for the solar twin 18 Sco to constrain stellar evolution models. 18 Sco is the brightest solar twin and is a good benchmark for the study of solar twins. The goal is to obtain realistic estimates of its physical characteristics (mass, age, initial chemical composition, mixing-length parameter) and realistic associated uncertainties using stellar models.

Methods.We set up a Bayesian model that relates the statistical properties of the data to the probability density of the stellar parameters. Special care is given to the modelling of the likelihood for the seismic data, using Gaussian mixture models. The probability densities of the stellar parameters are approximated numerically using an adaptive MCMC algorithm. From these approximate distributions we proceeded to a statistical analysis. We also performed the same exercise using local optimisation.

Results.The precision on the mass is approximately 6%. The precision reached onX0andZ0and the mixing-length parameter are respectively 6%, 9%, and 35%. The posterior density for the age is bimodal, with modes at 4.67 Gyr and 6.95 Gyr, the first one being slightly more likely. We show that this bimodality is directly related to the structure of the seismic data. When asteroseismic data or interferometric data are excluded, we find significant losses of precision for the mass and the initial hydrogen-mass fraction. Our final estimates of the uncertainties from the Bayesian analysis are significantly larger than values inferred from local optimization. This also holds true for several estimates of the age encountered in the literature.
A relaxed approach for curve matching with elastic metrics
Authors: Bauer Martin , Bruveris Martins , Charon Nicolas , Møller-Andersen Jakob
Published: September 2018

In this paper, we study a class of Riemannian metrics on the space of unparametrized curves and develop a method to compute geodesics with given boundary conditions. It extends previous works on this topic in several important ways. The model and resulting matching algorithm integrate within one common setting both the family ofH2-metrics with constant coefficients and scale-invariantH2-metrics on both open and closed immersed curves. These families include as particular cases the class of first-order elastic metrics. An essential difference with prior approaches is the way that boundary constraints are dealt with. By leveraging varifold-based similarity metrics we propose a relaxed variational formulation for the matching problem that avoids the necessity of optimizing over the reparametrization group. Furthermore, we show that we can also quotient out finite-dimensional similarity groups such as translation, rotation and scaling groups. The different properties and advantages are illustrated through numerical examples in which we also provide a comparison with related diffeomorphic methods used in shape registration.
Explicit exponential stabilization of nonautonomous linear parabolic-like systems by a finite number of internal actuators
Authors: Kunisch Karl , Rodrigues Sérgio S.
Published: September 2018

An explicit feedback controller is proposed for stabilization of linear parabolic equations, with a time-dependent reaction–convection operator. The range of the feedback controller is finite-dimensional, and is typically modeled by indicator functions of small subdomains. Its dimension depends polynomially on a suitable norm of the reaction–convection operator. A sufficient condition for stabilizability is given, which involves the asymptotic behavior of the eigenvalues of the (time-independent) diffusion operator, the norm of the reaction–convection operator, and the norm of the nonorthogonal projection onto the controller’s range along a suitable infinite-dimensional (higher-modes) eigenspace. To construct the explicit feedback, the essential step consists in computing the nonorthogonal projection. Numerical simulations are presented, in 1D and 2D, showing the practicability of the controller and its response to measurement errors, where the actuators are indicator functions of suitable small subsets.
The reasoning of mining methods parameters toward development of the apatite-nepheline ore deposits based on results of forecast of massif stress state
Authors: Bagautdinov Ilya , Kuranov Anton , Belyakov Nikita , Streshnev Anatoly
Published: September 2018

The article describes the experience in which the argumented parameters of the sublevel caving system in the conditions of mining operations take into account the Khibiny apatite-nepheline deposits. The stress state of the massif under the given conditions is determined by the parameters of the initial gravitational-tectonic field stresses, which have a complex distribution and redistribution for each individual isolating situation, which, in turn, is determined by the zone of the bearing pressure from the overlying stages. The necessary consideration of the factors indicated determined the order of the research: the parameters of regional field stress should be determined using the global numerical model of the deposit; after this, in order to justify the parameters of mining methods in local areas, it is necessary to make local numerical simulation for each area. All calculations were performed using Simulia Abaqus software, which implements the finite element method. Thus, the article presents numerical simulation of the stressed state of the massif of areas of “Plato Rasvumchorr” and “Apatitovii Tsirk” deposits and further describes the order of intersection of the results with the help of a global numerical model to a local numerical model of stope block at + 310 m at the Rusvumchorr mine. There are fixed minimum pillar sizes according to the accepted mining method in numerical simulation results using multiscale models.
Geomechanical justification of security measures in the development of the South Khingan deposit of manganese ore
Authors: Rasskazov Maksim , Potapchuk Marina , Kursakin Gennady , Tsoy Denis
Published: September 2018

The paper presents the results of geomechanical studies on the assessment of the potential rockburst hazard of the rock massif of the South Khingan deposit of manganese ore at the stage of development. Geodynamic zoning has been performed, mining and technical, mining and geological conditions of field development have been studied, and parameters of physical and mechanical properties of enclosing rocks and ores have been determined. Numerical simulation methods have been used to estimate the stress state of a rock massif at various stages of the deposit development. The tendency of the lower part of the South Khingan deposit to rockburst has been established. The complex of effective organizational and technical security measures has been substantiated in the development of this field.
Determination of the distortions introduced by the compression algorithm in the results of the measurement of the local impact control device “Prognoz-L”.
Authors: Migunov Dmitry , Grunin Alexey
Published: September 2018

The article discusses the application of the u-law algorithm from the G.711 standard, which performs lossy compression. A theoretical error introduced by this algorithm into discrete samples of digitized acoustic emission signals is determined. The effect of compression on signal parameters was also determined. During the analysis, the data from the local "Prognoz-L" device were used. "Prognoz-L" performs rockburst hazard assessment. The data were processed in an automatic mode to isolate pulsed signals containing acoustic emission. The processing of the obtained sample of pulse signals made it possible to determine the basic statistical characteristics of the errors introduced by the compression algorithm into the values of the signal parameters. The possibility of using this algorithm for preliminary processing of acoustic emission signals is established with the aim of keeping rock pressure monitoring in low-power acoustic-emission devices.
Evaluation of geomechanical conditions at Magnezitovaya mine when undermining natural and anthropogenic objects
Authors: Krinitsyn Roman , Avdeev Arkady , Khudyakov Sergei
Published: September 2018

Development of Satka magnesite deposit is carried out in complicated geomechanical conditions, in particular, mining works are conducted under the Bolshaya Satka river, in the zone of influence of the existing and developed quarries. Underground workings undermine a number of surface objects of industrial and civil purpose: railways, bridges, buildings and structures. There was an urgent need to conduct special studies of geomechanical conditions at the mine in order to assess the feasibility of working off part of the safety pillars located under the railway tracks of "Russian Railways", PJSC and the river bed. In the process of research, the main physical and mechanical properties of rocks have been identified, and the initial natural stresses of the rock mass have been measured. An increased level of horizontal initial stresses in the zone of safety pillars at the horizons + 180. + 260 m was detected. Based on the results of the research, a conclusion was made on the need to develop some engineering measures to ensure the safety of underground works. It was recommended, to ensure the stability of the rocks massif, to apply the option of extracting the treatment chambers with the formation of the ceiling of the vaulted form. It is proposed to monitor deformation processes in mine workings and on the daylight surface. To this end, the installation of an automated control system for rock pressure is recommended. It is necessary to provide for the establishment of long-term observation stations for controlling rock pressure and displacement. According to the results of the research, "Guidelines for the safe control of mining operations at bump-hazardous Satka magnesite deposit" have been developed in accordance with the requirements of the Federal norms and regulations in industrial safety.
Selective Desintegration and Concentration: Theory and Practice
Authors: Aleksandrova Tatyana , Nikolaeva N. , Lieberwirth Holger , Aleksandrov Alexander
Published: September 2018

Investigations on the possibility of selective grinding and benefication of quartz-pecoraite ores of the Ufaleiskoye deposit have been carried out. Methods of computer X-ray microtomography have been used to study the morphometric features and pore volume parameters of samples, and these data was compared with results of quantitative microstructural analysis. The performed research shows the powerful capabilities of X-ray computer microtomography method for solving scientific and practical problems related to the study of physical and mechanical properties of rocks, the determination of ore minerals liberation, the evaluation of their content, the analysis of the granulometric composition and the spatial distribution of their grains. Analysis of mineralogical and geochemical composition of ores showed that these ores meet the criteria for selective disintegration. An analysis of flotation experiments results showed that when material is grinded in a roll mill, the consumption of reagents is 25% lower than when grinding in a ball mill if the same degree of nickel extraction is achieved.
Iron manganese ores comprehensive processing
Authors: Gurman Margarita
Published: September 2018

This article illustrates the results of the study of leaching the resistant industrial products of manganese with the subsequent deposit of Mn from the solution with ammonia and hydrogen peroxide oxidizer. The chemical beneficiation of industrial products under optimal conditions aids in converting 96-98% manganese and its attendant iron into concentrates (in the form of sediments) containing 30.53-40.44% Mn and 10-15 % Fe, sludge cakes containing 80.36-83.81 % SiO2. It shows that the use of hydrometallurgy in combination with the beneficiation of hematitebraunite ores using gravity and magnetic radiation aids in the 10.39% increase of total manganese recovery in mineral form, (with 76-87.19 % increase in chemical form) and allows for integrated use of valuable components.
Integration of fiber lasers in processes of mineral raw material processing
Authors: Leonenko Nina
Published: September 2018

The application of laser technologies (LT) in the economy of the most developed countries. The possibility of using laser technologies for processing technogenic mineral raw materials is considered. The possibilities of integration of fiber-optic lasers into the processes of enrichment and processing of mineral raw materials are explored. The effects of interaction of laser radiation with mineral media - objects of Amur placer technogenic deposits containing submicron gold not extracted by modern gravitational methods are analyzed. The formation of selforganizing gold structures on the surface of a silicate matrix was established, general patterns of agglomeration and concentration of “nonextractable forms” of gold were revealed.
Obtaining preset properties in the hydrogenation process by controlling the state of phase boundary
Authors: Metaksa Galina , Moldabaeva Gulnaz , Alisheva Zhanat
Published: September 2018

The introduction of science-intensive technologies that ensure a high level of energy content and restoration of ecological balance in places of extraction and processing of commercial resources is the main condition for the successful development of independent Kazakhstan. This paper concentrates on challenges of studying the mechanisms of chemical effects on oil-reservoir rocks functioning in order to increase oil recovery. Relevance of addressing the challenges is determined by necessity to increase profitability of fossil hydrocarbons mining. The article is prepared based on the results of the works carried out within the framework of the Program of the State Science Academies for 2013-2020 period. “Earth Sciences” geological library Section No.9, “Integrated discovery and conservation of the Earth subsoils” line of fundamental research # 132, innovative processes of mineral deposits development and advenced processing of mineral raw materials”, “The Fundamental Basis of Oil and Gas Industry Innovative Technologies” project, No.ААА - 0139-2018- 0006.
Dielectric behavior of a quaternary composite (RE, BT, MnO2, CaO) in the band (DC–2 GHz)
Authors: Bouchaour Mounir , Martínez Jiménez Juan Pablo , Bouzit Nacerdine , Bourouba Nacerdine
Published: September 2018

The main objective of this paper is to study the dielectric behavior of a quaternary composite, made from a mixture of barium titanate (BT), manganese dioxide (MnO2) and calcium oxide (CaO) in the same epoxy resin matrix (RE) maintained at 70% by volume fraction, while those of the other constituents are variable and completing each other in a way to achieve the remaining proportion, i.e. 30%. Random mixtures are made at room temperature and under atmospheric pressure. A dielectric characterization of this mixture type was performed by time-domain spectroscopy (TDS) over a frequency wide band (DC–2 GHz). This has been carried out to illustrate the effect of two oxides (MnO2 and CaO) simultaneously at low frequency (500 MHz), in the presence of (BT), on the composite dielectric behavior. This has led consequently to make a comparison between the present acquired results and those of the ternary composite, where (MnO2) and (CaO) act separately. The results obtained so far in this study allowed us to check the validity of the modified Lichtenecker law (MLL)-based predictive model in the quaternary composite case. The interest of this study lies on applications of these materials in microelectronics circuits and absorber materials in telecommunication domain.
Nanohybrid scaffolds with luminescent remote control
Authors: Sochilina Anastasia V. , Savelyev Alexander G. , Sholina Natalya V. , Karimov Denis N. , Nechaev Andrey V. , Khaydukov Evgeny V. , Generalova Alla N.
Published: September 2018

We report on hybrid nanocomposite scaffolds on the base of cross-linked hyaluronic acid derivative with embedded upconversion nanoparticles (UCNPs). The unique photoluminescence properties of specially designed hydrophilic UCNPs enable visualization of hydrogel using NIR irradiation. Formation of scaffold structure can be produced by means of 3D printing or direct laser writing. For the first time, we present visualization of nanohybrid scaffolds in live small animal aiming to demonstrate new possibilities of their luminescent remote control for tissue engineering.
Aircraft digital assembly process design technology based on 3D Model
Authors: Chen Zhen , Tang Jianjun
Published: September 2018

In order to improve the quality, efficiency and cooperativity of aircraft assembly, based on the analysis of the characteristics of aircraft assembly process, a method for assembly process design, simulation and application based on three dimensional (3D) product model was proposed. The basic working process and system structure of the method were introduced, and the 3D digital assembly process planning, design and simulation optimization application mode was explored. This method has been applied in the design of aircraft assembly process, the efficiency and synergy of process design have been greatly improved.
Chatter Behavior in the Milling Process of Inconel 718: Effects of Tool Edge Radius
Authors: Hoe C H , Reddy M M , Lee V C C , Debnath S
Published: September 2018

Inconel 718 is widely used in various high end industries such as aerospace, nuclear plant, petrochemical plants etc. Inconel 718 is used for these applications due to unique mechanical properties such as high mechanical strength at elevated temperatures, high resistance to corrosion, and high strength to weight ratio. The unique properties of Inconel 718 made it difficult to be machined due to rapid work hardening and high cutting temperature. In addition, chatter vibration further increases the difficulty in machining of Inconel 718. In this paper, an experimental study on the effects of tool edge radius to the chatter behaviour was investigated. The dynamic responses of the milling process were recorded and analysed in both time domain and frequency domain. The results showed the variable helix and pitch end mill tool with larger tool edge radius able to mitigate chatter vibration at lower cutting speeds. Variable helix and pitch end mill with specific tool edge radius able to mitigate chatter vibration under the same cutting parameters. Experiments shows proper selection of tool edge radius improves the stability of end milling machining process.
Analysis on Rolling Damping of a Conventional Boat fitted with T-shaped Bilge Keels
Authors: San Yam Ke , Chiew Gordon , Howe Chin , Lee Vincent Chieng Chen , Roy Sukanta
Published: September 2018

This work presents a numerical study on the effect of T-shaped bilge keels on the roll damping of a conventional boat. A scaled boat model with the same dimensions as that of Irkal et al. [2] was fitted with two T-shaped bilge keels at the edges of the model. Computational Fluid Dynamics method was employed to simulate the roll decay motion of the boat. The motion of the boat is captured using a 6DOF model and the Overset grid approach. Comparison was performed on the damping characteristics of the conventional I-shaped and the T-shaped bilge keels. In addition, the impact of the aspect ratio of the keel bilges on the roll damping of the boat was evaluated. It was found that the bilge keel aspect ratio influences the damping coefficient non-linearly. Sufficiently large aspect ratio, i.e. an aspect ratio greater than 2, is necessary in order to obtain an effective damping on the peak angle.
Performance Comparison of Organic Rankine Cycle and Vapour Compression Cycle Hybrid Cooling-Heating System using Subcritical or Supercritical Working Fluid
Authors: Yam Ke San , Ismail Raja Wahiduzzaman Bin Raja , Lee Vincent Chieng Chen , Jung Hyung Chul
Published: September 2018

This paper presents a mathematical modelling on the evaluation of cooling, heating and power performance of a hybrid system of Organic Rankine Cycle and Vapour Compression Cycle. The system is assumed to be powered through solar parabolic trough collector and is able to generate a cooling power of 10 kW. Refrigerants R134a or R245fa are chosen as the working fluid of the system. The system is constructed using commercial energy modelling tool AspenPlus. Analysis is performed to determine the effect of changing the mass flow rate split ratio on the energy output. The effect of using subcritical and supercritical working fluid is also compared. Particular attention is paid toward the condition where the power output is equivalent to the energy consumption in view of creating a self-powered cooling and heating system. The result shows that the coefficient of performance for system using R245fa is higher compared to that using R134a. However, the system using R134a allows a self-powered cooling and heating system to be achieved to be achieve at a much higher mass split ratio, resulting the system to be 35% more efficient in the performance.
Individual Cylinder Air-Fuel Ratio Estimation for a Gasoline Engine with Electromagnetic Valve Train
Authors: Xu Yaxuan , Chang Siqin
Published: September 2018

For the multi cylinder gasoline engine, the consistency of each cylinder is an important index to affect the emission and the power. In this paper, in order to reduce the air-fuel ratio (A/F) maldistribution of the engine based on the electromagnetic valve train (EMVT), an individual cylinder A/F estimation algorithm is proposed for the individual cylinder A/F control. Based on the analysis of the hybrid and transfer models of the exhaust of each cylinder in steady state, an individual A/F observer is established by using Kalman filter algorithm. Then the unknown parameters in the observer are identified by the differential evolution(DE) algorithm. Only a single wide area exhaust oxygen(UEGO) sensor is needed to identify the unknown parameters and estimate the A/F of each cylinder. The combined simulation of GT-Power and Simulink validates the effectiveness of the proposed estimation approach. The results show that the proposed method can provide good estimation results under steady-state condition.
An Evolving Hypernetwork Model to Quantify Progress Potential of Emerging Research Topic
Authors: Liu Jia , Yang Kewei , Xu Jianguo , Gao Yingying , Yang Qingqing
Published: September 2018

There is considerable and growing interest in the emergence of research topics. However, current methods to detect the emergence are still problematic mainly due to information loss and aging effect. In this study, we show three intrinsic mechanisms including preferential attachment, exponentially growth and heterogeneous fitness values that decay with time. Depending on the input assumptions, all topics tend to follow a universal temporal pattern according to our model which results in strongly sufficiency to quantify progress potential.
A Fuzzy Adaptive Control of Doubly Fed Induction Machine (DFIM)
Authors: Saidi A. , Youb Lamia , Naceri Farid , Belkacem Sebti
Published: September 2018

In this paper, we are interested in the adaptive fuzzy control a technique has been studied and applied, namely adaptive fuzzy control based on theory of Lyapunov. The system based on the stability theory is used to approximate the gains Ke and kdce to ensure the stability of the control in real time .the simulations results obtained by using Matlab environment gives that the fuzzy adaptive control more robust, also it has superior dynamics performances. The results and test of robustness will be presented.
Probabilistic Matrix Factorization Recommendation Algorithm with User Trust Similarity
Authors: Dong Yuxin , Fang Shuyun , Jiang Kai , Chen Fukun , Yin Guisheng
Published: September 2018

In this paper, we describe the formatting guidelines for Conference Proceedings. Whether the user similarity calculation is reasonable in the traditional collaborative filtering recommendation algorithm directly affects the result of the collaborative filtering recommendation algorithm. This paper proposes a probabilistic matrix factorization recommendation algorithm with user trust similarity which combines improved similarity of users’ trust and probability matrix factorization recommendation method. The results show that proposed algorithm could relieve user cold start issues and effectively reduce the error of recommendation.
Clinical Characteristics of Patients with co-Existent Diabetic Peripheral Neuropathy and Depression: A Systematic Review
Authors: Zafeiri Maria , Tsioutis Constantinos , Kleinaki Zoe , Manolopoulos Philip , Ioannidis Ioannis , Dimitriadis George
Published: September 2018

Objectives Both diabetic peripheral neuropathy and depression have significant implications on patients’ quality of life, management and outcomes. We aimed to evaluate all available evidence concerning patients with co-existent diabetic peripheral neuropathy and depression, and describe their clinical characteristics, in order to promote early recognition and management.

Methods Systematic search of PubMed for studies providing data on patients with diabetic peripheral neuropathy and depression. The primary outcome was to evaluate all available evidence related to characteristics of diabetes, diabetic peripheral neuropathy and depression. Secondary study outcomes included comorbid conditions and complications in these patients.

Results Final analysis included 24 studies with data on 205 patients. Most patients were adults between 18–65 years of age. Mean HbA1c value was above 8% and most patients were treated with insulin. Neuropathy was predominantly painful and most patients with available data were considered to have major depressive disorder. In addition to diabetic peripheral neuropathy and depression, diabetes-related complications were recorded in 43 patients, the most common being autonomic neuropathy, retinopathy and nephropathy. The most frequently reported comorbidities were weight loss (72 patients), impotence (60 patients), hypertension (23 patients) and coronary artery disease (22 patients).

Conclusions The present study describes the characteristics of patients with co-existent diabetic peripheral neuropathy and depression, aiming for prompt detection, prevention of further deterioration and improvement of patient outcomes. Available evidence shows that the majority of these patients are adults, with painful peripheral neuropathy and with insulin-treated and inadequately controlled diabetes.
Symmetric Multiple Carbohelicenes
Authors: Kato Kenta , Segawa Yasutomo , Itami Kenichiro
Published: September 2018

This account focuses on the synthesis and structures of symmetric multiple carbohelicenes; i.e., fully fused polycyclic aromatic hydrocarbons containing two or more symmetric helicene moieties. Synergies of the multiplexed helicene structures within a π-system generate a number of local minima and transition states between each state. Based on recent studies on multiple helicenes, a systematic molecular design for further multiplexed symmetric helicenes is proposed in the last section of this article.
Synthesis and Photophysical Properties of Hexaphenylbenzene–Pyrrolo[3,2-b]pyrroles
Authors: Jux Norbert , Gryko Daniel , Stężycki Rafał , Reger David , Hoelzel Helen
Published: September 2018

Methods for the synthesis of pyrrolo[3,2-b]pyrroles containing hexaphenylbenzene moieties at the 2- and 5-positions or the 1- and 4-positions have been developed. It was shown that placing a hexaphenylbenzene moiety at the 2- and 5-positions requires a Diels–Alder reaction between an alkyne-substituted pyrrolopyrrole core and a 2,3,4,5-tetraphenylcyclopenta-2,4-dien-1-one. The resulting dyes show a strong blue fluorescence that was hypsochromically shifted by chlorination at the 3- and 6-positions. The overall conjugation between the hexaphenylbenzene moieties and the pyrrolopyrrole core is limited, as evident from their photophysical properties. The hexaphenylbenzene moieties attached to the pyrrolo[3,2-b]pyrrole core could not be transformed into hexa-peri-hexabenzocoronenes through intramolecular oxidative aromatic coupling.
A Synthetic Route to the MT1-MMP Inhibitor Ancorinoside D
Authors: Schobert Rainer , Petermichl Markus , Steinert Christine
Published: September 2018

A methyl ester of ancorinoside D, a 3-acyltetramic acid metabolite of a sponge Penares sollasi, was synthesised in ten steps starting from a protected β-d-glucopyranosyl-(1→4)-d-galactopyranosyltrichloroacetimidate donor. Its attachment to the left half of the 3-acyl spacer by a Schmidt glycosylation, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation to the uronic acid, introduction of the Z-alkene via Wittig reaction, and functionalisation of the spacer terminus with Meldrum’s acid gave a β-keto ester that reacted with dimethyl N-methyl-d-aspartate under neutral conditions to afford a fully protected ancorinoside D as the product of an unusual domino N-acylation–Dieckmann condensation. Global deprotection left a methyl ester of ancorinoside D, which resisted all saponification attempts.
Copper(I)-Catalyzed Thiolation of C–H Bonds for the Synthesis of Sulfenyl Pyrroles and Indoles
Authors: Deng Chen-Liang , Xu Wei , Hei Yu-Yuan , Song Jian-Lan , Zhan Xin-Chen , Zhang Xing-Guo
Published: September 2018

A novel and convenient copper(I)-catalyzed thiolation of C–H bonds of pyrroles and indoles is developed for the synthesis of sulfenyl pyrroles and indoles. Dual C–H thiolation reactions are observed for pyrroles. A wide range of pyrroles and indoles undergo the C–H thiolation smoothly with various disulfides and diselenides to generate the corresponding heteroaryl thioethers in moderate to excellent yields.
Fe(ClO4)3·H2O-Catalyzed Ritter Reaction: A Convenient Synthesis of Amides from Esters and Nitriles
Authors: Ji Min , Feng Chengliang , Yan Bin , Yin Guibo , Chen Junqing
Published: September 2018

An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with esters catalyzed by Fe(ClO4)3·H2O is described. Fe(ClO4)3·H2O is an economically efficient catalyst for the Ritter reaction under solvent-free conditions. Reactions of a range of esters (benzyl, sec-alkyl, and tert-butyl esters) with nitriles (primary, secondary, tertiary, and aryl nitriles) were performed to provide the corresponding amides in high to excellent yields.
Nutrition for Hypercholesterolemic Children
Authors: Martín-Martínez Benjamín , López-Liñán María
Published: September 2018

In the diet of hypercholesterolemic children, 10 to 18% of the total calorie intake should be protein, 50 to 60% carbohydrates, and 30% lipids, of which less than 10% should be saturated fatty acids, between 7 and 10% should be polyunsaturated fatty acids, and 10 to 20% should be monounsaturated fatty acids. Cholesterol intake should not exceed 300 mg/dL, and an adequate fiber intake of 8 to 28 g/day, according to the child's age, should be ensured. If a child is obese or overweight, the aim of the initial treatment should be to normalize weight through improved lifestyle habits, dietary recommendations, and increased physical activity. The healthy diet for cardiovascular disease prevention is similar to that advised for a healthy pediatric population: (1) reduced total fat intake, such as through eating less red meat and sausages and choosing skimmed milk, butter, skimmed-milk cheese, lean meat, skinless chicken, and rabbit, cooked using simple cooking processes; (2) increased intake of monounsaturated and polyunsaturated oils, such as fish oil and olive oil; (3) reduced cholesterol intake, such as through the reduced consumption of eggs, viscera, and industrial bakery products; and (4) higher intake of fish and complex carbohydrates, such as pasta, pulses, and whole-grain bread. In addition, fruits and vegetables should be recommended for their fiber, vitamins, minerals, and trace elements. The recommended culinary preparation is to grill, steam, or bake food and to avoid frying, especially with butter or animal fat, and to give preference to oils based on monounsaturated fats, such as olive and sunflower oil.
Child Nutrition and Bone Health
Authors: Redondo-Cuevas Lucía , Sanchis-Chordà Jesús , Codoñer-Franch Pilar
Published: September 2018

Nutrition is one of the modifiable factors that contributes to bone accrual during childhood and adolescence, a critical period to prevent adult osteoporosis. Calcium and vitamin D seem to be the most important nutrients for optimal bone growth. Requirements for calcium intake are different among countries and organizations, and exact recommendations are difficult to determine since other dietary factors directly affect calcium metabolism, such as salt intake and vitamin D levels. Some scientists have suggested that the actual calcium requirements are overestimated and that increased dairy intake does not necessarily translate to better bone health in adults. Moreover, calcium can be obtained from other natural foods, such as cruciferous vegetables (turnip greens, broccoli rabe, kale, broccoli, and cabbage), endive, sesame seeds, legumes, almonds, calcium-fortified vegetable beverages, and canned sardines. Vitamin D should be obtained from food combined with appropriate sun exposure, and if that is not enough, vitamin D supplements can be used. Diets comprised a complex combination of nutrients and foods, and dietary patterns in children and adolescents play a key role in bone formation. A dietary pattern that is high in vegetables and fruits and low in processed foods (containing large amounts of added sugar and salt) is necessary to achieve optimal bone formation. Finally, physical activity, particularly activities that apply large forces, is even more important than dietary factors to contribute to bone accrual.
Adolescent Feeding: Nutritional Risk Factors
Authors: Carrasco-Luna Joaquín , Gombert Marie , Carrasco-García Álvaro , Codoñer-Franch Pilar
Published: September 2018

The aim of this review is to describe adolescent nutritional requirements from a scientific, nutritional, and psychosocial point of view, emphasizing the main risks of malnutrition at this age. Currently, too many teenagers are alone at home and prepare their own meals. The influence of friends replaces parental rules. The habits of adolescents are characterized by a tendency to skip meals, especially breakfast, and, less frequently, the midday meal; to purchase carry-out meals away from home; to consume snacks, especially sweets; to eat at fast food restaurants, almost always with high-calorie content; and to eat fried foods, soft drinks, and sweets. Toxic habits, such as smoking, alcohol, and drugs, interfere with a healthy diet, as well. Physical activity usually decreases during adolescence, particularly in girls. The lack of physical activity is due to a precarious knowledge of the benefits associated with practicing physical activity, low motivation, time constraints, and, in many cases, the lack of adequate facilities. Adolescents interested in a body image in accordance with modern ideals follow restrictive and unbalanced diets without any nutritional basis, which they themselves planned. These behaviors increase the risk of nutritional alterations, such as noncompliance with nutritional requirements, meal pattern irregularities, nutritional problems due to low nutrient intake, and self-esteem issues and frustration. In general, in this age group, there is an increase in protein consumption and salt content, often with a supply of unbalanced nutrients, high-fat diets (35–50% of total calories), and low polyunsaturated/saturated fat ratio. In addition, adolescents consume a low level of complex carbohydrates, fiber, fruits, and vegetables.
Circadian Rhythm Variations and Nutrition in Children
Authors: Gombert Marie , Carrasco-Luna Joaquín , Pin-Arboledas Gonzalo , Codoñer-Franch Pilar
Published: September 2018

Circadian rhythms are the changes in biological processes that occur on a daily basis. Among these processes are reactions involved in metabolic homeostasis. Circadian rhythms are structured by the central clock in the suprachiasmatic nucleus of the hypothalamus via the control of melatonin expression. Circadian rhythms are also controlled by the peripheral clocks, which are intracellular mechanisms composed of the clock genes, whose expression follows a circadian pattern. Circadian rhythms are impacted by signals from the environment called zeitgebers, or time givers, which include light exposure, feeding schedule and composition, sleeping schedule and pattern, temperature, and physical exercise. When the signals from the environment are synchronized with the internal clocks, metabolism is optimized. The term chronodisruption is used to describe the opposite situation. The latest research has demonstrated that life habits coherent with the internal clocks should be adopted, especially during childhood, to prevent metabolic diseases. Nevertheless, a few studies have investigated this link in children, and key information remains unknown.
Orphan Three-Finger Toxins Bind at Tissue Factor–Factor VIIa Interface to Inhibit Factor X Activation: Identification of Functional Site by Docking
Authors: Choudhury Manisha , McCleary Ryan , Kini R. Manjunatha , Velmurugan Devadasan
Published: September 2018

Three-finger toxins (3FTxs) contribute to toxicity of venomous snakes belonging to the family Elapidae. Currently, functions of a considerable proportion of 3FTxs are still unknown. Here, we describe the function of orphan group I 3FTxs consisting of four members. We also identified a new member of this group by sequencing a transcript isolated from Naja naja venom. This transcript, named najalexin, is identical to that previously described 3FTx from Naja atra venom gland, and shared high sequence identity with ringhalexin from Hemachatus haemachatus and a hypothetical protein from Ophiophagus hannah (here named as ophiolexin). The three-dimensional structure, as predicted by molecular modeling, showed that najalexin and ophiolexin share the same conserved structural organization as ringhalexin and other 3FTxs. Since ringhalexin inhibits the activation of factor X by the tissue factor–factor VIIa complex (TF-FVIIa), we evaluated the interaction of this group of 3FTxs with all components using in silico protein–protein docking studies. The binding of orphan group I 3FTxs to TF-FVIIa complex appears to be driven by their interaction with TF. They bind to fibronectin domain closer to the 170-loop of the FVIIa heavy chain to inhibit factor X activation. The docking studies reveal that functional site residues Tyr7, Lys9, Glu12, Lys26, Arg34, Leu35, Arg40, Val55, Asp56, Cys57, Cys58, and Arg65 on these 3FTxs are crucial for interaction. In silico replacement of these residues by Ala resulted in significant effects in the binding energies. Furthermore, these functional residues are not found in other groups of 3FTxs, which exhibit distinct pharmacological properties.
Invited Article: Advances in tunable laser-based radiometric calibration applications at the National Institute of Standards and Technology, USA
Authors: Woodward John T. , Shaw Ping-Shine , Yoon Howard W. , Zong Yuqin , Brown Steven W. , Lykke Keith R.
Published: September 2018

Recent developments at the National Institute of Standards and Technology’s facility for Spectral Irradiance and Radiance responsivity Calibrations using Uniform Sources (SIRCUS) are presented. The facility is predicated on the use of broadly tunable narrow-band lasers as light sources in two key radiometric calibration applications. In the first application, the tunable lasers are used to calibrate the spectral power responsivities of primary standard detectors against an absolute cryogenic radiometer (ACR). The second function is to calibrate the absolute radiance and irradiance responsivities of detectors with uniform light sources, typically generated by coupling the laser light into integrating spheres. The radiant flux from the uniform sources is determined by the ACR-calibrated primary standard detectors. Together these sources and detectors are used to transfer radiometric scales to a variety of optical instruments with low uncertainties. We describe methods for obtaining the stable, uniform light sources required for low uncertainty measurements along with advances in laser sources that facilitate tuning over broader wavelength ranges. Example applications include the development of a detector-based thermodynamic temperature scale, the calibration and characterization of spectrographs, and the use of a traveling version of SIRCUS (T-SIRCUS) to calibrate large aperture Earth observing instruments and astronomical telescopes.
Magnetization reversal in bent nanofibers of different cross sections
Authors: Blachowicz Tomasz , Ehrmann Andrea
Published: September 2018

Ferromagnetic nanofibers and nanofiber based networks with new electronic, magnetic, mechanical, and other physical properties can be considered significant components of bio-inspired cognitive computing units. For this purpose, it is necessary to examine all relevant physical parameters of such nanofiber networks. Due to the more or less random arrangement of the nanofibers, first of all, the elementary single nanofibers with varying bending radii, from straight fibers to those bent along half-circles, were investigated by micromagnetic simulations, using different angles with respect to the external magnetic field. Different fiber cross sections, i.e., circular, circle-segment, rectangular, significantly altered the coercive fields and their dependence on the bending radius, for the magnetic field oriented differently in relation to the fiber axes. The shapes of the longitudinal and transverse hysteresis curves showed strong differences, depending on cross section, bending radius, and orientation to the magnetic field, often depicting distinct transverse magnetization peaks perpendicular to the fibers for fibers which were not completely oriented parallel to the magnetic field. Varying these parameters thus provides a broad spectrum of magnetization reversal processes in magnetic nanofibers and correspondingly scenarios for a variety of fiber-based information processing.
On the extraction of the boundary conditions and the boundary ports in second-order field theories
Authors: Schöberl Markus , Schlacher Kurt
Published: September 2018

In this paper, we consider second-order field theories in a variational setting. From the variational principle, the Euler-Lagrange equations follow in an unambiguous way, but it is well known that this is not true for the Cartan form. This also has consequences on the derivation of the boundary conditions when non-trivial variations are allowed on the boundary. By posing extra conditions on the set of possible boundary terms, we exploit the degree of freedom in the Cartan form to extract physical meaningful boundary expressions. The same mathematical machinery will be applied to derive the boundary ports in a Hamiltonian representation of the partial differential equations which is crucial for energy based control approaches. Our results will be visualized for mechanical systems such as beam and plate models.
Multi-angle multi-pulse time-resolved Thomson scattering on laboratory plasma jets
Authors: Banasek J. T. , Rocco S. V. R. , Potter W. M. , Byvank T. , Kusse B. R. , Hammer D. A.
Published: September 2018

A single channel sub-nanosecond time-resolved Thomson scattering system used for pulsed power-driven high energy density plasma measurements has been upgraded to give electron temperatures at two different times and from two different angles simultaneously. This system was used to study plasma jets created from a 15 μm thick radial Al foil load on a 1 MA pulsed power machine. Two laser pulses were generated by splitting the initial 2.3 ns duration, 10 J, 526.5 nm laser beam into two pulses, each with 2.5 J, and delaying one relative to the other by between 3 and 14 ns. Time resolution within each pulse was obtained using a streak camera to record the scattered spectra from the two beams from two scattering angles. Analysis of the scattering profile showed that the electron temperature of the Al jet increased from 20 eV up to as much as 45 eV within about 2 ns by inverse bremsstrahlung for both laser pulses. The Thomson scattering results from jets formed with opposite current polarities showed different laser heating of the electrons, as well as possibly different ion temperatures. The two-angle scattering determined that the electron density of the plasma jet was at least 2 × 1018 cm−3.
Steady state magnetic sensors for ITER and beyond: Development and final design (invited)
Authors: Kocan M. , Duran I. , Entler S. , Vayakis G. , Agostinetti P. , Brombin M. , Carmona J. M. , Gambetta G. , Jirman T. , Marconato N. , Moreau P. , Peruzzo S. , Spuig P. , Walsh M.
Published: September 2018

The measurements of the magnetic field in tokamaks such as ITER and DEMO will be challenging due to the long pulse duration, high neutron flux, and elevated temperatures. The long duration of the plasma pulse makes standard techniques, such as inductive coils, prone to errors. At the same time, the hostile environment, with repairs possible only on blanket exchange, if at all, requires a robust magnetic sensor. This contribution presents the final design of novel, steady-state, magnetic sensors for ITER. A poloidal array of 60 sensors mounted on the vacuum vessel outer shell contributes to the measurement of the plasma current, plasma-wall clearance, low-frequency MHD modes and will allow for crosscheck with the outer-vessel inductive coils. Each sensor hosts a pair of bismuth Hall probes, themselves an outcome of extensive R&D, including neutron irradiations (to 1023 n/m2), temperature cycling tests (73–473 K) and tests at high magnetic field (to 12 T). A significant effort has been devoted to optimize the sensor housing by design and prototyping. The production version features an indium-filled cell for in situ recalibration of the onboard thermocouple, vital for the interpretation of the Hall sensor measurement.
Coarse-grained modeling of multiphase interactions at microscale
Authors: Huang Pengyu , Shen Luming , Gan Yixiang , Nguyen Giang D. , El-Zein Abbas , Maggi Federico
Published: September 2018

The objective of this study is to develop and test a coarse-grained molecular dynamics framework to model microscale multiphase systems with different inter-particle interactions and recover emerging thermodynamic and mechanical properties at the microscale. A water-vapor model and a fused silica model are developed to demonstrate the capability of our framework. The former can reproduce the water density and surface tension over a wide range of temperatures; the latter can reproduce experimental density, tensile strength, and Young’s modulus of fused silica. Therefore, the deformable solid model is implemented in the proposed framework. Validations of spatial scaling methods for solid, liquid, and multiphase systems suggest that the proposed framework can be calibrated at an arbitrary microscale and used at a different length scale without recalibration. Different values of wettability for a solid-liquid-vapor system that is characterized by the contact angle can be achieved by changing the solid-liquid inter-particle potential. Thanks to these features, the proposed coarse-grained molecular dynamics framework can potentially find applications in modeling systems in which multiple phases coexist and have substantial interactions.