bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficiency of vermicompost production and use in agriculture
Authors: Shetinina Elena , Shetinina Arina , Potashova Irina
Published: April 2019

The relevance of the study is due to the need to eliminate the environmental problems associated with the irrational use of chemical fertilizers in agriculture. Biohumus is an environmentally friendly natural fertilizer, which is produced by processing food waste ringworms, whose natural habitat is compost mass and not mineral soils. Thus, the production does not violate the flora and fauna and at the same time is environmentally friendly and waste-free. Practical significance of the study consists in the development of measures, the implementation of which will allow solving environmental problems caused by the irrational use of chemical fertilizers. As part of the study, the authors proposed using biohumus as a natural fertilizer, which allows, on the one hand, reducing the chemical effect on the soil cover, reducing the chemical elements content in finished agricultural products, eliminating the plants treatment with pesticides, and on the other hand, increasing the natural yield, developing immunity in plants of various species, and improving the physical properties of the soil layers.
Assessment of acoustic and pulsation characteristics of centrifugal pumps
Authors: Zharkovskiy Aleksandr , Borshev Igor , Ivanov Evgeniy , Donskoy Anatoliy , Klyuyev Arsentiy
Published: April 2019

Numerical investigations of unsteady viscous flow in centrifugal pumps were conducted in this paper. Verification of numerical approach was done. Hydraulic components of the pump were modernized with the purpose to improve their acoustic characteristics. Modernization was held on the base of isotropic turbulence noise measuring techniques. Results were confirmed by experiment. Pressure pulsations were studied in a flow between rotating impeller and stator for initial and improved flowing parts. As a result of numerical research, various impellers with different blade outlet angles were designed. During optimization, the optimal blade outlet angle was found, which provides increased vibroacoustic characteristics while maintaining a high level of efficiency.
Environmental safety of green construction and requirements of urban planning legislation
Authors: Voskresenskaya Elena , Vorona-Slivinskaya Lybov , Panov Sergey
Published: April 2019

The vector that defines the strategy of innovative development of the construction industry in Russia consists in providing conditions for increasing labor productivity, reducing energy intensity and prime cost of construction process by means of introducing new institutional mechanisms that allow directing the development of the construction complex to the implementation of green construction (ecological construction) investment projects. Today, the conditions for performing green construction as an innovative and energy-efficient solution of environmental management problems are being provided in Russia taking into account modern environmental requirements. The article discusses some problems and issues of green construction, considering architecture and construction areas that are aimed at erection and operation of buildings with soft impact on the nature. In order to ensure environmental safety, the effectiveness of elaboration and implementation of investment projects for green construction should be substantiated taking into account the ecological-and-economic model of the life cycle based on the subject-oriented approach. The present scientific article defines the state and trend of green construction development in the investment-and-construction sector, analyzes environmental safety and methods of creating the innovative green building development platform. The authors recommend developing a methodological outfit to optimize the interaction of economic entities of green construction. The optimization will help to assess the effectiveness of improving the innovative green building platform and the level of environmental safety.
Application of environmentally friendly concrete demolition techniques in the repair of shipping locks
Authors: Bazanov Vladimir
Published: April 2019

The paper analyzes the traditional mechanic technique of concrete demolition and the promising hydro demolition techniques from viewpoint of waterworks operators. The mechanical concrete demolition technique using chisel hammers is immediately available for the use and relatively cheap, but it is associated with considerable labor cost, generation of dust and noise. Concrete hydro demolition technique using high-pressure water has much higher productivity and reduces repair completion time, does not damage reinforcement, and ensures good adhesion of new concrete to old concrete. Basic technical characteristics of hydro demolition equipment and its pricing are given. On the basis of the current situation with regard to the estimated regulation and financing of construction projects, including from budgetary funds, the author considered the possibility of using promising methods of removing exposed concrete of lock chamber walls. A comparison was made between the cost and the regulatory and actual labor intensity between the methods of mechanical and hydraulic destruction of concrete. It has been shown that application of the hydraulic demolition technique is constrained by financial capabilities and estimates regulatory requirements. For substantiation of using the concrete hydro demolition techniques, operators need to adjust the regulatory framework for federal assessments.
Agrotourism as an element of the development of a green economy in a resort area
Authors: Baranova Alla , Kegeyan Svetlana
Published: April 2019

Due to the deterioration of the environmental situation in the world, many countries are interested in a strategy of “green growth” that combines efforts in the field of economics, ecology, sociology, health care, and technology. One of the environmentally friendly activities is agrotourism. Russian regions have a huge natural and recreational potential for agrotourism, which has a high socio-economic importance for municipalities in terms of the development of small and medium-sized businesses, the creation of additional jobs, the formation of the added value of the tourist product. However, there are negative factors: low level of infrastructure development, lack of a recognizable brand, poor transport accessibility to the objects of agrotourism, seasonality of agricultural products, weak state financial support for the development of entrepreneurship in rural areas, lack of investors’ interest. The paper presents main features of the development of agrotourism in the resort area (for example, the resort city of Sochi) that has the properties of a “green economy” and can contribute to “green growth”.
Road service facilities for improving the ecological state using the PPP mechanism
Authors: Subbotin Artem , Grigoryan Sevada
Published: April 2019

The relevance of this work is associated with the creation of methodological foundations for the formation of effective organizational forms and ways to improve the quality of road maintenance, the development of conditions that prevent different types of environmental pollution, compliance with environmental protection and environmental safety throughout the length of road transport routes. The study solves the following tasks: analysis of the development of systems and complexes that prevent environmental pollution, the development of road service facilities with the infrastructure for the environmental mode of transport, substantiation of the organizational form and scheme of interaction between the state and private business in the Russian Federation for the implementation of road service facilities, comparison of Russian and international experience in the development of these facilities. The organizational form of construction of road service facilities using the public-private partnership (PPP) mechanism in the Russian Federation is a priority from an economic point of view and effective for the development of facilities that contribute to the improvement and compliance with environmental safety requirements. The most effective type of construction in this industry is modular construction. Combining PPP and modular type of construction is the most priority method of cooperation for private entrepreneurs. The minimum construction time and the availability of the roadside service will accordingly improve the conditions for movement of road users and, thus, the ecological state.
Current state of labour productivity in the economy of developed countries
Authors: Bogatyreva Irina , Simonova Marina , Privorotskaya Elena
Published: April 2019

The article is devoted to the problems of labour productivity increase. It studies trends in labour productivity growth in 12 developed countries and presents a comparative analysis of individual factors that directly affect labour productivity indicators in some European countries as well as the USA and Japan. The article examines and analyzes the reasons for Russia’s lagging behind the developed countries of Europe and the USA in terms of labour productivity; the detailed analysis of the level and dynamics of labour productivity in the Russian economy is given. The authors of the article calculated indicators of labour productivity, indicators of the ratio of the average wage growth rates in the economy of the Samara region. Special attention is paid to the study of organizational and socioeconomic factors of increasing labour productivity in conditions of limited financial resources.
Regional environmental safety assessment
Authors: Ganebnykh Elena , Burtseva Tatyana , Petuhova Anastasia , Mottaeva Angela
Published: April 2019

The article provides a comparative analysis of the regions of the Volga Federal District, Russia to identify the dependence of industrial development on the environment. The research collected statistical information for all regions of the district and used it as a basis for constructing a perception map showing the actual regional situations compared to the “ideal point”.
Implementation of ecological audit in the enterprises activities for the benefit of the environment
Authors: Vasilyeva Elena , Mottaeva Angela
Published: April 2019

The author believes that the problems connected with the impact on the environment are very relevant, including the matters of the assessment of damage caused to it and the matters of the assessment of risk from this damage for the users of nature, as well as for the state institutes, which are carrying out control, for private and public organizations. The current situation in Russia is characterized by the need of introduction of new ecologic-and-economic concepts, such as ecological audit and revision of the role and value of old economic tools in the state policy. The scheme of ecological audit, its main directions in Russia at the level of the enterprise, regions and the country in general as well as within the international cooperation are considered in the article. At the same time, some problems connected with legislation shortcomings exist. Besides, the author emphasizes the inadmissibility to solve the environmental problems at the expense of detriment of economic interests, the need of balanced and reasonable decisions.
Preparation of the procedure of virtual organization development in construction
Authors: Slavina Anastasiia , Zhumaev Malik , Chadkina Yana , Tereshenko Diana
Published: April 2019

The use of virtual structures in the area of CAD may have an impact on the design labour coefficient and on the works cost reduction. When developing and further functioning of virtual structures in organization, there are a number of issues related to the employees search and employment, work with CAD, with staff, payment for activities, acquisition and storage of information, reporting, interaction between the virtual team members, etc. The full activity of project organizations, both within the large and independent companies, requires for new procedural developments based on the information systems. The procedure of virtual structures development and implementation in organization is proposed to resolve this issue.
Stability analysis and error estimates of arbitrary Lagrangian–Eulerian discontinuous Galerkin method coupled with Runge–Kutta time-marching for linear conservation laws
Authors: Zhou Lingling , Xia Yinhua , Shu Chi-Wang
Published: April 2019

In this paper, we discuss the stability and error estimates of the fully discrete schemes for linear conservation laws, which consists of an arbitrary Lagrangian–Eulerian discontinuous Galerkin method in space and explicit total variation diminishing Runge–Kutta (TVD-RK) methods up to third order accuracy in time. The scaling arguments and the standard energy analysis are the key techniques used in our work. We present a rigorous proof to obtain stability for the three fully discrete schemes under suitable CFL conditions. With the help of the reference cell, the error equations are easy to establish and we derive the quasi-optimal error estimates in space and optimal convergence rates in time. For the Euler-forward scheme with piecewise constant elements, the second order TVD-RK method with piecewise linear elements and the third order TVD-RK scheme with polynomials of any order, the usual CFL condition is required, while for other cases, stronger time step restrictions are needed for the results to hold true. More precisely, the Euler-forward scheme needs τ ≤ ρh2 and the second order TVD-RK scheme needs $ \tau \le \rho {h}^{\frac{4}{3}}$ for higher order polynomials in space, where τ and h are the time and maximum space step, respectively, and ρ is a positive constant independent of τ and h.
An operational effectiveness evaluation method of the swarming UAVs air combat system
Authors: Jia Niping , Yang Zhiwei , Yang Kewei
Published: April 2019

In this paper, we propose an operational effectiveness evaluation method of the swarming UAVs air combat system. The system network model is firstly established before the evaluation. We divide the edges in the network into nine types according to the Generalized Operation Loop and give the edge attribute of operational information entropy based on node attributes. When calculating the system operational effectiveness, we focus on the striking ability and propose the concept of Operation Loop Capability to represent the target-attack effectiveness of a certain operational loop, which can be calculated from the edge operational information entropies. We can get the combat effectiveness to a certain target from the Operation Loop Capability, and the combat effectiveness of the swarming UAVs air combat system is represented by the sum of the striking capabilities to all targets. Finally, the scene of swarming UAVs air combat is taken as a case study to apply and verify our evaluation method. This paper gives a quantitative perspective on swarming UAVs combat system assessment and can help to analyze the contribution of UAVs and other weapons in the system.
Applying the AcciMap methodology to investigate the tragic Mirsharai road accident in Bangladesh
Authors: Hamim Omar Faruqe , Hoque Md. Shamsul , McIlroy Rich C. , Plant Katherine L. , Stanton Neville A.
Published: April 2019

A serious road accident happened on Monday, 11 July, 2011 afternoon in Mirsharai sub-district of Bangladesh's Chittagong district, that killed at least 44 schoolboys injured many more when the truck in which they were traveling skidded off a highway and plunged into a canal. In this study, the AcciMap methodology is applied, an extension to Rasmussen’s Risk Management Framework. This sociotechnical framework provides an insight into the interactions between different levels of a system, and supports the development of recommendations that could mitigate or prevent the outcomes of such an incident in the future. In the case of Mirsharai accident, the police and social media put the blame on the truck driver alone; however, this study, based on popular media reports, accident investigation reports and local interviews revealed mismanagement and an apparent disregard for safety across different levels of the socio-technical system. By integrating the different levels of the system, from international committees to end users, the road accident scenario of Bangladesh can be improved through developing a systematic approach to accident analysis.
Deep convolutional neural networks for cardiovascular vulnerable plaque detection
Authors: Li Lincan , Jia Tong , Meng Tianqi , Liu Yizhe
Published: April 2019

In this paper, an accurate two-stage deep learning method is proposed to detect vulnerable plaques in ultrasonic images of cardiovascular. Firstly, a Fully Convonutional Neural Network (FCN) named U-Net is used to segment the original Intravascular Optical Coherence Tomography (IVOCT) cardiovascular images. We experiment on different threshold values to find the best threshold for removing noise and background in the original images. Secondly, a modified Faster RCNN is adopted to do precise detection. The modified Faster R-CNN utilize six-scale anchors (122,162,322,642,1282,2562) instead of the conventional one scale or three scale approaches. First, we present three problems in cardiovascular vulnerable plaque diagnosis, then we demonstrate how our method solve these problems. The proposed method in this paper apply deep convolutional neural networks to the whole diagnostic procedure. Test results show the Recall rate, Precision rate, IoU (Intersection-over-Union) rate and Total score are 0.94, 0.885, 0.913 and 0.913 respectively, higher than the 1st team of CCCV2017 Cardiovascular OCT Vulnerable Plaque Detection Challenge. AP of the designed Faster RCNN is 83.4%, higher than conventional approaches which use one-scale or three-scale anchors. These results demonstrate the superior performance of our proposed method and the power of deep learning approaches in diagnose cardiovascular vulnerable plaques.
Animal species classification using machine learning techniques
Authors: Alharbi Fahad , Alharbi Abrar , Kamioka Eiji
Published: April 2019

Animals recognition is one of the research areas in which few effective technologies have been proposed, especially in the predator animals' domain. Predator animals present a great danger to people who are camping or staying in outdoor areas and they are also a menace to livestock. In this paper, a multiple feature detection of predator animals is proposed. This method focuses on the face of the animal, explicitly the eyes and the ears. A database was created by collecting the features of ears and eyes from 10 animals and an experiment was conducted using machine learning techniques such as SVM and MLP to classify them as predators or pets. The evaluation results achieved the classification accuracies of 82% for MLP and 78% for SVM, which justify its effectiveness for the proposed method.
Action recognition based on 2D skeletons extracted from RGB videos
Authors: Aubry Sophie , Laraba Sohaib , Tilmanne Joëlle , Dutoit Thierry
Published: April 2019

In this paper a methodology to recognize actions based on RGB videos is proposed which takes advantages of the recent breakthrough made in deep learning. Following the development of Convolutional Neural Networks (CNNs), research was conducted on the transformation of skeletal motion data into 2D images. In this work, a solution is proposed requiring only the use of RGB videos instead of RGB-D videos. This work is based on multiple works studying the conversion of RGB-D data into 2D images. From a video stream (RGB images), a two-dimension skeleton of 18 joints for each detected body is extracted with a DNN-based human pose estimator called OpenPose. The skeleton data are encoded into Red, Green and Blue channels of images. Different ways of encoding motion data into images were studied. We successfully use state-of-the-art deep neural networks designed for image classification to recognize actions. Based on a study of the related works, we chose to use image classification models: SqueezeNet, AlexNet, DenseNet, ResNet, Inception, VGG and retrained them to perform action recognition. For all the test the NTU RGB+D database is used. The highest accuracy is obtained with ResNet: 83.317% cross-subject and 88.780% cross-view which outperforms most of state-of-the-art results.
Pelletization performance of Panzhihua ilmenite concentrate
Authors: Song Bing , Huang Ping , Ma Yong , Song Zan , He Zhake
Published: April 2019

The influences of particle size distribution and the binder on the pelletization performance of Panzhihua ilmenite concentrate were studied in this paper. The results showed that the particle size distribution of Panzhihua ilmenite concentrate has the most important on its pelletization. The particle size distribution of ilmenite concentrate was significant changed and the specific surface area increased after grinding. The particle size of 45μm should be controlled less than 55% and 74μm no more than 74% in order to acquire a better performance of pellets. While the same performance of pellets can be obtained when the specific surface area of ilmenite concentrate was 1493cm2/g. The performance of pellets added with an organic binder is better than added bentonite. The pellet’s performance could be further improved under the mixed ratio of 1.05% bentonite and 0.45% organic binder.
Skeleton based gait recognition for long and baggy clothes
Authors: Alharbi Abrar , Alharbi Fahad , Kamioka Eiji
Published: April 2019

Human gait is a significant biometric feature used for the identification of people by their style of walking. Gait offers recognition from a distance at low resolution while requiring no user interaction. On the other hand, other biometrics are likely to require a certain level of interaction. In this paper, a human gait recognition method is presented to identify people who are wearing long baggy clothes like Thobe and Abaya. Microsoft Kinect sensor is used as a tool to establish a skeleton based gait database. The skeleton joint positions are obtained and used to create five different datasets. Each dataset contained different combination of joints to explore their effectiveness. An evaluation experiment was carried out with 20 walking subjects, each having 25 walking sequences in total. The results achieved good recognition rates up to 97%.
Determination of temperature dependences of Young's modulus and internal friction of fuel cladding by resonance method
Authors: Moshev A A , Martynenko S P , Martynenko S S , Kudryavtsev E M , Ableyev A N , Tokarev A N , Panasenko R A , Rodko I I , Maksimkin A I , Zhukovskii Y O , Belendryasova E G
Published: April 2019

We study elastic characteristics and internal friction of fuel claddings to improve computer codes for VVER-1000 fuel rods. We analytically described elastic characteristics of cladding material and obtained coefficient of the form of the first longitudinal frequency numerically. We described new measuring module for automatic acquisition data. We’ve established temperature dependences of Young’s modulus and internal friction via high-temperature facility and developed electronic module and noted maximum of these characteristics at the temperature 1160 K. It can be explained by the destruction of the texture in the material of claddings.
A policy iteration algorithm for nonzero-sum stochastic impulse games
Authors: Aïd René , Bernal Francisco , Mnif Mohamed , Zabaljauregui Diego , Zubelli Jorge P.
Published: April 2019

This work presents a novel policy iteration algorithm to tackle nonzero-sum stochastic impulse games arising naturally in many applications. Despite the obvious impact of solving such problems, there are no suitable numerical methods available, to the best of our knowledge. Our method relies on the recently introduced characterisation of the value functions and Nash equilibrium via a system of quasi-variational inequalities. While our algorithm is heuristic and we do not provide a convergence analysis, numerical tests show that it performs convincingly in a wide range of situations, including the only analytically solvable example available in the literature at the time of writing.
A class of finite-dimensional numerically solvable McKean-Vlasov control problems
Authors: Balata Alessandro , Huré Côme , Laurière Mathieu , Pham Huyên , Pimentel Isaque
Published: April 2019

We address a class of McKean-Vlasov (MKV) control problems with common noise, called polynomial conditional MKV, and extending the known class of linear quadratic stochastic MKV control problems. We show how this polynomial class can be reduced by suitable Markov embedding to finite-dimensional stochastic control problems, and provide a discussion and comparison of three probabilistic numerical methods for solving the reduced control problem: quantization, regression by control randomization, and regress-later methods. Our numerical results are illustrated on various examples from portfolio selection and liquidation under drift uncertainty, and a model of interbank systemic risk with partial observation.
Bias behaviour and antithetic sampling in mean-field particle approximations of SDEs nonlinear in the sense of McKean
Authors: Bencheikh O. , Jourdain B.
Published: April 2019

In this paper, we prove that the weak error between a stochastic differential equation with nonlinearity in the sense of McKean given by moments and its approximation by the Euler discretization with time-step h of a system of N interacting particles is 𝒪(N-1+h). We provide numerical experiments confirming this behaviour and showing that it extends to more general mean-field interaction and study the efficiency of the antithetic sampling technique on the same examples.
On the implementation of a primal-dual algorithm for second order time-dependent Mean Field Games with local couplings
Authors: Briceño-Arias L. , Kalise D. , Kobeissi Z. , Laurière M. , Mateos González Á. , Silva F. J.
Published: April 2019

We study a numerical approximation of a time-dependent Mean Field Game (MFG) system with local couplings. The discretization we consider stems from a variational approach described in [14] for the stationary problem and leads to the finite difference scheme introduced by Achdou and Capuzzo-Dolcetta in [3]. In order to solve the finite dimensional variational problems, in [14] the authors implement the primal-dual algorithm introduced by Chambolle and Pock in [20], whose core consists in iteratively solving linear systems and applying a proximity operator. We apply that method to time-dependent MFG and, for large viscosity parameters, we improve the linear system solution by replacing the direct approach used in [14] by suitable preconditioned iterative algorithms.
High Incidence of Renal Stones in Severely Disabled Children with Epilepsy Treated with Topiramate
Authors: Ishikawa Nobutsune , Tani Hiroo , Kobayashi Yoshiyuki , Kato Akira , Kobayashi Masao
Published: April 2019

Purpose This study was aimed to assess the accurate incidence of renal stones in severely disabled children treated with topiramate (TPM).

Method We reviewed the medical records of severely disabled children with epilepsy under 15 years old who underwent radiological examinations to investigate urinary stones. The study enrolled 26 patients who were divided into two groups. One group had been treated with TPM for at least 1 year and the other had not been treated with TPM, zonisamide, acetazolamide, or other diuretic drugs. We collected parameters from the medical records and compared the groups.

Results All participants were evaluated radiologically, with computed tomography (CT) in two patients, ultrasonography in 22 patients, and both in two. No patient had any morphological abnormality of the kidneys and history of urinary tract infection. There were no significant differences in sex, age, body weight, or feeding manner between the groups, while the incidence of renal stones or calcifications was significantly higher in the TPM-treated group (60 vs. 0%; p = 0.00241).

Conclusion There is a high incidence of renal stone formation in severely disabled children treated with TPM.
Impacted Mandibular Third Molars and Their Influence on Mandibular Angle and Condyle Fractures
Authors: Mehra Anhad , Anehosur Venkatesh , Kumar Niranjan
Published: April 2019

The aim of this study is to retrospectively analyze the effect unerupted or partially erupted third molars have on the angle and condyle fracture patterns of the mandible. It also focuses on evaluating the type of impaction that causes angle fracture and the level at which the condyle most commonly fractures. The study involves all the patients who had undergone treatment for condylar and angle of the mandible fractures from 2010 to 2017 in our craniofacial center. The case records and orthopantomograms of each patient were taken into consideration and a correlation was established based on gender, age, etiology, presence of third molars, position of third molars, angulation, and root development of third molars. Of the 150 angle fracture patients, 146 had third molars and 4 did not, whereas of the 130 condyle fractures, third molar was present in 54 patients and absent in 76. The prevalence of angle fractures was statistically significant when a third molar was present, whereas the prevalence of condyle fractures was higher when third molar was absent. The results of age, etiology, angulation, position, and root development of third molars were also statistically significant. However, sex of the patient did not influence the fracture pattern. The presence of an impacted third molar or a completely erupted one has a definite influence on the fracture pattern of the mandible. The occurrence of angle and condyle fractures was mostly affected by the continuity of the cortical bone at the angle of the mandible. Hence, prophylactic removal of mandibular third molars does increase the risk of condyle fractures.
What drives people to believe in Zika conspiracy theories?
Authors: Klofstad Casey A. , Uscinski Joseph E. , Connolly Jennifer M. , West Jonathan P.
Published: April 2019

Conspiracy theories and other pseudo-scientific claims about the Zika virus have been prominent on social media. To what extent are the public concerned about the virus, and to what extent have the public adopted Zika conspiracy theories? Using data from the 2016 Cooperative Congressional Election Study, we show that a majority of Americans are not concerned about the Zika virus, but approximately one in five Americans believes in at least one Zika-related conspiracy theory. The most widely believed is that the virus is caused by genetically modified mosquitoes. We find that elevated levels of conspiracy thinking are correlated with both concern over Zika and belief in Zika-related conspiracy theories. For example, a person scoring the maximum on the conspiratorial thinking scale is estimated to believe in .61 Zika conspiracy theories while a person scoring the minimum is estimated to believe in only .06 Zika conspiracy theories. This study demonstrates the role of predispositions, specifically underlying conspiracy thinking, in the acceptance of conspiratorial and unscientific beliefs.
Novel high temperature vacuum nanoindentation system with active surface referencing and non-contact heating for measurements up to 800 °C
Authors: Conte Marcello , Mohanty Gaurav , Schwiedrzik Jakob J. , Wheeler Jeffrey M. , Bellaton Bertrand , Michler Johann , Randall Nicholas X.
Published: April 2019

High temperature nanoindentation is an emerging field with significant advances in instrumentation, calibration, and experimental protocols reported in the past couple of years. Performing stable and accurate measurements at elevated temperatures holds the key for small scale testing of materials at service temperatures. We report a novel high temperature vacuum nanoindentation system, High Temperature Ultra Nanoindentation Tester (UNHT3 HTV), utilizing active surface referencing and non-contact heating capable of performing measurements up to 800 °C. This nanoindenter is based on the proven Ultra Nano-Hardness Tester (UNHT) design that uses two indentation axes: one for indentation and another for surface referencing. Differential displacement measurement between the two axes enables stable measurements to be performed over long durations. A vacuum level of 10−7 mbar prevents sample surface oxidation at elevated temperatures. The indenter, reference, and sample are heated independently using integrated infrared heaters. The instrumental design details for developing a reliable and accurate high temperature nanoindenter are described. High temperature calibration procedures to minimize thermal drift at elevated temperatures are reported. Indentation data on copper, fused silica, and a hard coating show that this new generation of instrumented indenter can achieve unparalleled stability over the entire temperature range up to 800 °C with minimum thermal drift rates of <2 nm/min at elevated temperatures.
Thermionic-enhanced near-field thermophotovoltaics for medium-grade heat sources
Authors: Datas A. , Vaillon R.
Published: April 2019

Conversion of medium-grade heat (temperature from 500 to 1000 K) into electricity is important in applications such as waste heat recovery or power generation in solar thermal and co-generation systems. At such temperatures, current solid-state devices lack either high conversion efficiency (thermoelectrics) or high-power density capacity (thermophotovoltaics and thermionics). Near-field thermophotovoltaics (nTPV) theoretically enables high-power density and conversion efficiency by exploiting the enhancement of thermal radiation between a hot emitter and a photovoltaic cell separated by nanometric vacuum gaps. However, significant improvements are possible only at very small gap distances (<100 nm) and when ohmic losses in the photovoltaic cell are negligible. Both requirements are very challenging for current device designs. In this work, we present a thermionic-enhanced near-field thermophotovoltaic (nTiPV) converter consisting of a thermionic emitter (graphite) and a narrow bandgap photovoltaic cell (InAs) coated with low-workfunction nanodiamond films. Thermionic emission through the vacuum gap electrically interconnects the emitter with the front side of the photovoltaic cell and generates an additional thermionic voltage. This avoids the use of metal grids at the front of the cell and virtually eliminates the ohmic losses, which are unavoidable in realistic nTPV devices. We show that nTiPV operating at 1000 K and with a realizable vacuum gap distance of 100 nm enables a 10.7-fold enhancement of electrical power (6.73 W/cm2) and a 2.8-fold enhancement of conversion efficiency (18%) in comparison with a realistic nTPV device having a series resistance of 10 mΩ·cm2.
Quantum well infrared photo-detectors operating in the strong light-matter coupling regime
Authors: Vigneron Pierre-Baptiste , Pirotta Stefano , Carusotto Iacopo , Tran Ngoc-Linh , Biasiol Giorgio , Manceau Jean-Michel , Bousseksou Adel , Colombelli Raffaele
Published: April 2019

We report quantum well mid-infrared photo-detectors operating in the strong light-matter coupling regime. We claim that this is an ideal system to elucidate the elusive problem in intersubband polaritonics of the injection of electrons (single-particle fermionic states) into polaritonic modes (bosonic excitations). By reversing the perspective and focusing on the electron extraction, we have obtained experimental information on the transfer function between a polaritonic system and an electronic reservoir. In addition to its interest for fundamental science, this approach also opens promising avenues in view of adding previously unavailable functionalities to quantum well detectors and improving their performance.
Parallel propagating electromagnetic waves in magnetized quantum electron plasmas
Authors: Woo C. H. , Woo M. H. , Choi Cheong R. , Min K. W.
Published: April 2019

In this paper, we derive the quantum Vlasov equation as a differential equation of the Wigner function directly from the electromagnetic Schrödinger equation and apply it to the plasma waves propagating in the direction parallel to the ambient magnetic field. The upper branches of the L and R waves in the plot of (ω, k) space have dispersion relations similar to those of their respective classical waves, with only minor corrections. The lower R-wave branch also has a dispersion relation similar to that of the classical whistler wave for a small wavenumber k. However, the dispersion curve encounters a region of anomalous dispersion, exhibiting a negative group velocity, as k increases. Furthermore, the branch becomes a damping wave as k increases above a certain critical value and eventually the wave becomes ill-defined for larger k values.
A finite state projection method for steady-state sensitivity analysis of stochastic reaction networks
Authors: Dürrenberger Patrik , Gupta Ankit , Khammash Mustafa
Published: April 2019

Consider the standard stochastic reaction network model where the dynamics is given by a continuous-time Markov chain over a discrete lattice. For such models, estimation of parameter sensitivities is an important problem, but the existing computational approaches to solve this problem usually require time-consuming Monte Carlo simulations of the reaction dynamics. Therefore, these simulation-based approaches can only be expected to work over finite time-intervals, while it is often of interest in applications to examine the sensitivity values at the steady-state after the Markov chain has relaxed to its stationary distribution. The aim of this paper is to present a computational method for the estimation of steady-state parameter sensitivities, which instead of using simulations relies on the recently developed stationary finite state projection algorithm [Gupta et al., J. Chem. Phys. 147, 154101 (2017)] that provides an accurate estimate of the stationary distribution at a fixed set of parameters. We show that sensitivity values at these parameters can be estimated from the solution of a Poisson equation associated with the infinitesimal generator of the Markov chain. We develop an approach to numerically solve the Poisson equation, and this yields an efficient estimator for steady-state parameter sensitivities. We illustrate this method using several examples.
Microscopic analysis of thermo-orientation in systems of off-centre Lennard-Jones particles
Authors: Jack Robert L. , Wirnsberger Peter , Reinhardt Aleks
Published: April 2019

When fluids of anisotropic molecules are placed in temperature gradients, the molecules may align themselves along the gradient: this is called thermo-orientation. We discuss the theory of this effect in a fluid of particles that interact by a spherically symmetric potential, where the particles’ centres of mass do not coincide with their interaction centres. Starting from the equations of motion of the molecules, we show how a simple assumption of local equipartition of energy can be used to predict the thermo-orientation effect, recovering the result of Wirnsberger et al. [Phys. Rev. Lett. 120, 226001 (2018)]. Within this approach, we show that for particles with a single interaction centre, the thermal centre of the molecule must coincide with the interaction centre. The theory also explains the coupling between orientation and kinetic energy that is associated with this non-Boltzmann distribution. We discuss deviations from this local equipartition assumption, showing that these can occur in linear response to a temperature gradient. We also present numerical simulations showing significant deviations from the local equipartition predictions, which increase as the centre of mass of the molecule is displaced further from its interaction centre.
Dielectric resonator method for determining gap symmetry of superconductors through anisotropic nonlinear Meissner effect
Authors: Bae Seokjin , Tan Yuewen , Zhuravel Alexander P. , Zhang Lingchao , Zeng Shengwei , Liu Yong , Lograsso Thomas A. , Ariando  , Venkatesan T. , Anlage Steven M.
Published: April 2019

We present a new measurement method which can be used to image the gap nodal structure of superconductors whose pairing symmetry is under debate. This technique utilizes a high quality factor microwave resonance involving the sample of interest. While supporting a circularly symmetric standing wave current pattern, the sample is perturbed by a scanned laser beam, creating a photoresponse that was previously shown to reveal the superconducting gap anisotropy. Simulation and the measurement of the photoresponse of an unpatterned Nb film show less than 8% anisotropy, as expected for a superconductor with a nearly isotropic energy gap along with expected systematic uncertainty. On the other hand, measurement of a YBa2Cu3O7−δ thin film shows a clear 4-fold symmetric image with ∼12.5% anisotropy, indicating the well-known 4-fold symmetric dx2−y2 gap nodal structure in the ab-plane. The deduced gap nodal structure can be further cross-checked by low temperature surface impedance data, which are simultaneously measured. The important advantage of the presented method over the previous spiral resonator method is that it does not require a complicated lithographic patterning process which limits one from testing various kinds of materials due to photoresponse arising from patterning defects. This advantage of the presented technique, and the ability to measure unpatterned samples such as planar thin films and single crystals, enables one to survey the pairing symmetry of a wide variety of unconventional superconductors.
Molecular structure of a hyperactive antifreeze protein adsorbed to ice
Authors: Meister K. , Moll C. J. , Chakraborty S. , Jana B. , DeVries A. L. , Ramløv H. , Bakker H. J.
Published: April 2019

Antifreeze proteins (AFPs) are a unique class of proteins that bind to ice crystal surfaces and arrest their growth. The working mechanism of AFPs is not well understood because, as of yet, it was not possible to perform molecular-scale studies of AFPs adsorbed to the surface of ice. Here, we study the structural properties of an AFP from the insect Rhagium mordax (RmAFP) adsorbed to ice with surface specific heterodyne-detected vibrational sum-frequency generation spectroscopy and molecular dynamic simulations. We find that RmAFP, unlike other proteins, retains its hydrating water molecules upon adsorption to the ice surface. This hydration water has an orientation and hydrogen-bond structure different from the ice surface, thereby inhibiting the insertion of water layers in between the protein and the ice surface.
Microscopic velocity field measurements inside a regular porous medium adjacent to a low Reynolds number channel flow
Authors: Terzis A. , Zarikos I. , Weishaupt K. , Yang G. , Chu X. , Helmig R. , Weigand B.
Published: April 2019

This study examines experimentally the hydrodynamic interaction between a regular porous medium and an adjacent free-flow channel at low Reynolds numbers (Re < 1). The porous medium consists of evenly spaced micro-structured rectangular pillars arranged in a uniform pattern, while the free-flow channel features a rectangular cross-sectional area. The overall arrangement comprises a polydimethylsiloxane microfluidic model where distilled water, doped with fluorescent particles, is the examined fluid. Using micro-particle image velocimetry, single-phase quantitative velocity measurements are carried out at the pore scale to reveal the microscopic characteristics of the flow for such a coupled system. Interfacial velocity-slip and stress-jump coefficients are also evaluated with a volume-averaging method based on the Beavers-Joseph and Ochoa-Tapia-Whitaker models, respectively. The results show that, from a microscopic point of view, parallel flow at the interface is not obtained due to the periodically generated U-shaped flow profile between the interface pillars. However, the interface coefficients show no sensitivity to moderate flow angles. The highly resolved experimental information obtained in this study can also be used for the validation of numerical models providing a unique dataset for free-flow and porous media coupled systems.
Racial disparities in school-based disciplinary actions are associated with county-level rates of racial bias
Authors: Riddle Travis , Sinclair Stacey
Published: April 2019

There are substantial gaps in educational outcomes between black and white students in the United States. Recently, increased attention has focused on differences in the rates at which black and white students are disciplined, finding that black students are more likely to be seen as problematic and more likely to be punished than white students are for the same offense. Although these disparities suggest that racial biases are a contributor, no previous research has shown associations with psychological measurements of bias and disciplinary outcomes. We show that county-level estimates of racial bias, as measured using data from approximately 1.6 million visitors to the Project Implicit website, are associated with racial disciplinary disparities across approximately 96,000 schools in the United States, covering around 32 million white and black students. These associations do not extend to sexuality biases, showing the specificity of the effect. These findings suggest that acknowledging that racial biases and racial disparities in education go hand-in-hand may be an important step in resolving both of these social ills.
O-GlcNAcylation of core components of the translation initiation machinery regulates protein synthesis
Authors: Li Xuexia , Zhu Qiang , Shi Xiaoliu , Cheng Yaxian , Li Xueliu , Xu Huan , Duan Xiaotao , Hsieh-Wilson Linda C. , Chu Jennifer , Pelletier Jerry , Ni Maowei , Zheng Zhiguo , Li Sihui , Yi Wen
Published: April 2019

Significance

Protein synthesis is essential for cell growth, proliferation, and survival. Deregulation of protein synthesis is an important feature in many diseases. However, how protein synthesis is regulated under physiological and pathological conditions still remains poorly understood. In this study, we report an unknown mechanism for the regulation of protein synthesis in cells. We demonstrate that two important translation initiation factors, namely eIF4A and eIF4G, are modified by a single sugar N-acetylglucosamine. Detailed analyses show that this modification influences the interaction and function of these two proteins, and regulates protein synthesis at the initiation stage. This finding expands the current understanding of protein synthesis and adds a dimension of complexity to translational control of cellular proteins in cells.
Ammonia emission control in China would mitigate haze pollution and nitrogen deposition, but worsen acid rain
Authors: Liu Mingxu , Huang Xin , Song Yu , Tang Jie , Cao Junji , Zhang Xiaoye , Zhang Qiang , Wang Shuxiao , Xu Tingting , Kang Ling , Cai Xuhui , Zhang Hongsheng , Yang Fumo , Wang Huanbo , Yu Jian Zhen , Lau Alexis K. H. , He Lingyan , Huang Xiaofeng , Duan Lei , Ding Aijun , Xue Likun , Gao Jian , Liu Bin , Zhu Tong
Published: April 2019

Significance

Atmospheric ammonia plays important roles in fine particle pollution, acid rain, and nitrogen deposition. China, known as the world’s top emitter of gaseous ammonia, plans to control ammonia emissions to mitigate the haze pollution that has recently emerged. However, the complex side effects are still unclear. By integrating a chemical transport model, nationwide measurements, and a sophisticated ammonia emission model, we find that ammonia emission control would significantly aggravate acid rain pollution, thereby offsetting the benefit from reduced fine particle pollution and nitrogen deposition. Our work suggests that region-specific ammonia-control strategies provide a more rational and effective way to achieve the dual benefits of protecting human and ecosystem health in China.