bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the nature of destruction of castings made of 35HGSL steel after a long service life
Authors: Skryabin M L , Poyarkov M S
Published: May 2020

Today, castings of their alloy steels are an integral part of modern foundry production. In the process of obtaining castings, any defects inevitably appear. This paper deals with the issues of stone-like destruction of castings made of 35HGSL steel after a long service life. The paper compares the macro-and microstructures of the rock-like fracture and based on the analysis revealed that its causes are large grain and the presence of impurities in steel in the form of sulfides or nitrides, which are located on the grain boundaries and weaken them. The influence of ferrite layers around bainite grains on the presence of the studied defect was also revealed.
Research of stability of rotor of the knife grinding refiners
Authors: Vikharev S
Published: May 2020

An object of research is stability of provision of rotor in the knife grinding refiners. Dynamic and mathematical models of rotor in bearing support are developed. Expression for determination of force of a preliminary tightness in bearing support for stabilization of the situation of rotor is received. Amplitude of fluctuations of disk of rotor in bearings with tightness is much less than in bearings with gap. For ensuring stability of an interknife gap of refiners it is recommended to eliminate radial gaps in bearing knots, i.e. to use bearings with a preliminary tightness. It will allow to raise a technical resource of the grinding plate. The technique of researches can be applied in other high-precisionmachines, for example, in the metalworking equipment.
Intensification of heat transfer by mixing in pyrolysis units during oil waste disposal
Authors: Kolenchukov O A , Petrovsky E A , Mikhaylov A Yu , Bashmur K A , Smirnov N A
Published: May 2020

This article provides an overview of the most common mixing devices. Their advantages and disadvantages are presented, as well as a mathematical description of the heat transfer process. Revealed the most promising designs for mixing oil waste. The design of the developed mixing device is shown.
The technology of manufacture of the pistons of the heat engine by the method of liquid stamping
Authors: Skryabin M L , Poyarkov M S
Published: May 2020

Modern methods of production of heat engine pistons allow to strengthen individual parts of the piston with composite materials based on ceramics. The considered manufacturing technology allows reinforcing the bottom of the piston, thereby increasing the reliability of individual parts of the piston that perceive maximum temperatures during operation. The pistons obtained by this method have an increased heat transfer coefficient and a finer-grained metal structure. Also, the use of ceramic materials in pistons can increase the reliability and service life of engines.
Doubly fed inductor electric drive model for automation systems
Authors: Bronov Sergej , Stepanova Elena , Avlasko Pavel , Nukulin Nikolaj , Krivova Darya , Bisov Aleksej
Published: May 2020

The doubly fed inductor electric motor is the basis of the electric drive. It has two three-phase windings which can have different connection schemes: «separate connection», «star», «delta». Each scheme has its own advantages which are manifested in various modes of operation. The existing electric drive models are designed for the most used connection scheme «star». The models for other winding connection schemes are not available. This does not allow to study the modes of operation with other winding connection schemes. In doubly fed electric drives each winding can have its own connection diagram. The existing models also do not provide such an opportunity. The new models of the doubly fed inductor electric drive can be used with various winding connection schemes – «separate connection», «star» and «delta». Each motor winding can have its own winding diagram. The method of nodal potentials enables to simulate the windings switching during the process of their modeling. This model of electric drive is more universal than the existing ones and provides more research opportunities.
Geometric calculation of planetary rotor hydraulic machines
Authors: Kurasov Dmitry
Published: May 2020

Hydraulic and pneumatic volume displacement machines are commonly the most important and integral elements of modern mechanical systems. One of the known types of such machines is planetary rotor hydraulic machines (PRHM) with floating satellites in contact with central gearwheels. The numbers of the central gearwheels «waves» M and N may be different or the same. They are characterized by the absence of valves and loaded kinematic sliding pairs. The main task of design and calculation of PRHM is geometrical calculation of their gear elements. Such a task has to be solved in the case of a PRHM with two non-circular centre gearwheels and a PRHM with round and non-circular centre gearwheels. The developed method of geometric synthesis of PRHM allows to obtain profiles of PRHM gear elements.
Definition of factors limiting the growth of industrial production
Authors: Morkovkin D E , Gibadullin A A , Safarov B G , Alpatova E A
Published: May 2020

Issues related to the formation of new types of industrial production have been relevant in recent years, since it is industry that creates new technologies, products, provides human life and the existence of the state, in this regard, the authors of the study present this work. The transition of the industrial structure from one stage to another allows us to offer new scientific and practical solutions that ensure the development of industrial potential. The work revealed that industrial production in Russia is in stagnation and there are no changes in this area of activity. Based on the obtained data, a factor model was proposed, which made it possible to identify factors limiting the development of industrial production.
Organizing the cash flow management in the construction industry in the Russian Federation
Authors: Ketova К V , Rusyak I G , Kasatkina E V , Saburova E A , Vavilova D D
Published: May 2020

This paper presents a mathematical model of organizing the cash flow management in implementing an apartment building construction plan in the context of using an escrow account in the Russian Federation. A mathematical model of organizing the cash flow management implies an in-creased income of productive activities in the construction industry by means of changing the volume of sales in square meters and sale prices. Furthermore, a mathematical model enables us to determine the sales strategy of a construction organization, which would provide a minimum lending rate for minimizing a percentage rate which is paid by the construction organization. According to the monthly financing schedule of a building project, a mathematical model of organizing the cash flow management enables us to calculate the most suitable escrow account balance, as well as the volume of sales in square meters. Calculating rise in profitability of financial resources in the construction industry is exemplified by an average developer of one of Russia’s regions in which residential construction grows rapidly – the Udmurt Republic.
The analysis of changes in the payroll of information system support specialists during the Devops methodology implementing
Authors: Aliev I , Gazul S , Bobova A
Published: May 2020

For a wide range of tasks, especially in the field of software development, the use of modern platforms for virtualization and containerization of applications can significantly increase the density of computing nodes (virtual machines and containers) on the equipment. In addition, the use of CI and CD practices can save the working time of employees responsible for supporting such IT infrastructure. At the same time, specialists supporting such IT infrastructure should have a number of additional competencies. The purpose of this article is to analyze the cost of specialists supporting information systems built using virtualization technologies, cloud computing in the context of CI and CD practices. This article presents an analysis of all available relevant vacancies in Saint Petersburg and Moscow from the HeadHunter site. Also, the difference between the required competencies and the level of salaries of specialists supporting classical and virtualized, automated IT infrastructure is shown.
Face recognition methods
Authors: Dzhangarov A I , Suleymanova M A , Zolkin A L
Published: May 2020

Nowadays, a science as cybernetics is gaining popularity. World society is on the verge of digitalization a technological and social sectors of human life. One of the most popular areas of cybernetics is computer vision. Systems of video assistants that recognize images and objects are widely distributed, and social test and control systems are introduced in test mode. In this regard, the relevance of research in this area is extremely high. This paper provides an analysis of the available methods for recognizing faces in images and discusses the software implementation of one of them.
Contemporary state of the confidential information leakages through the cloud data repositories
Authors: Kalach A V , Timofeeva E A , Bakhteeva D A , Dayneko D D , Spirin VA
Published: May 2020

Information concerning the leakage of the confidential data held in the cloud repositories of Amazon, Mongo DB, in the file hosting of Google Drive kind, as well as cloud servers for back-up in the period of 2016-2018. Certain conclusions made concerning necessity for the development of the systems enabling information security with the use of the cloud technologies at the expense of cyber-resilience enhancement.
A parallel algorithm for finding the human face in the image
Authors: Zaynidinov H N , Mallaev O U , Anvarjonov B B
Published: May 2020

It is well-known that anyone who processes and analyzes image information needs a large amount of memory for storing images. For example, for storing a standard TV frame, if two of the three colors contain 2 bits for each of the 3 bits, the memory of at least 512×512 bytes is required. A passport image must be at least 64×64×64 bits (this requires more space than any other passport data). The problems associated with storage, search, and discovery are made more complex by processing and analyzing large numbers of images. The image contains a large amount of information, so it is natural for them to have excessive statistical, psychovisual and content information. Due to this redundancy, the process of digital image processing, image retrieval time, and storage capacity increase. The use of parallel technologies in digital processing of images plays an important role in solving the above problems. Therefore, the article presents an algorithm for calculating the process of extracting a human face from a color image using MPI technology.
An informational approach to quantizing the effectiveness of test data arrays for static memory devices
Authors: Akinina Ju S , Bolnokin V E , Tyurin S V , Akinin A A , Popov S A
Published: May 2020

While testing of the Static Random Access Memory (SRAM) the effective detection of potential faults is mostly determined by the structure and the algorithm of test arrays of data generation. This article proposes a multiplicative indicator W, which allows us to quantify the quality of test arrays of data. It is necessary to represent test arrays of data as a binary matrix, where each column corresponds to a certain bit of SRAM, and the rows correspond to test patterns. In this case, the process of sequential formation of test patterns is identified with the percolation process on a rectangular grid. It is assumed that percolation occurs at the moment when the maximization of the binary antagonisms both on the rows and on the columns of the binary matrix is provided. In this case, the binary sequences in all columns of the matrix must be different. Preliminary experimental data allows to suggest that the evaluation of the quality of test arrays of data based on the proposed indicator W can simultaneously be considered as the maximum efficiency of detecting a certain class of potential SRAM faults in a certain order of reading test data.
Computing process as a diagnostic object
Authors: Oblomov I A , Rzhavin V V , Pervova N V , Fadeeva K N , Gerasimova A G
Published: May 2020

The issues of improving the reliability of the functioning of the computing process are in the focus of attention of many developers and researchers of computer systems. Based on an analysis of research in this area, we came to the conclusion that the theory of reliability of computing systems has not yet been adequately developed, and none of the available groups of methods provides a satisfactory solution to the problems of reliable functioning of the computing process under given restrictions on cost and efficiency. The article discusses the main software methods of diagnosis and control, highlights their significant shortcomings. The conclusion is drawn on the need to develop new methods of program control and diagnostics of the computation process. These methods should ensure reliable functioning of the computing process in the conditions of hardware failures, and allow recovering the computing process and data from the consequences of failures in an acceptable time for the diagnosed process. The definition of the computing process as a sequence of elementary acts on a change in the state of the environment is refined. A path has been outlined for choosing mathematical models of the computing process, the most suitable of which are schemes of programs and algorithms.
Packet fragmentation as data protection method in automated systems
Authors: Gorokhov D E , Ryabokon V V , Kuzkin A A , Sherbakov V S , Kutsakin M A
Published: May 2020

The paper gives a detailed description of the information transfer covert channels and their main types. One of the most popular protection methods, the one with the software and the hardware applied to traffic encryption, against the information disclosure threat is considered. Experimental data obtained from the statistical analysis of the encrypted traffic and contributing into the identification of different modern info-communication services by the IP-package distribution and the time intervals between their arrival are collected and provided. A detailed classification of the information transfer covert channels is looked upon under the regulating documents in the in-formation protection sphere. An overall mechanism of a convert channel functioning in the automated systems is described. The areas to counteract the convert channels as an information disclosure threat are specified. The authors put forward a protection method employing IP fragmentation. A diagram of a pilot stand for the videoconference systems which was tested during the experiment is presented. The parameters and the characteristics of the obtained results are described. The results are analysed, and the possible applications of IP fragmentation as a method to counteract the information transfer convert channels in the videoconference systems are offered.
Thermal bar studies in the Krasnoyarsk Reservoir based on remote sensing datasets
Authors: Bondarenko E V , Gosteva A A , Shaparev N Ya
Published: May 2020

We study a possibility of using remote sensing datasets to identify a thermal bar in the Krasnoyarsk Reservoir. MODIS thermal band data have been used to produce sets of images showing temporal and spatial temperature distribution across the Krasnoyarsk Reservoir. Thematic maps of temperature distribution across the reservoir have been derived for the spring period of 2016-2019, which show the thermal bar period to commence and end up within about one and the same time interval.
Complete ultrashort pulse decomposition in modal filters with circular symmetry
Authors: Belousov A O , Gazizov T T
Published: May 2020

The work carried out simulation and optimization of structures with circular symmetry which is multiconductor lines to protect critical equipment from very fast acting pulses. Six cross section configurations of structures with circular symmetry are considered. Through parametric optimization, a complete splitting of the actuating pulse signal is achieved when the structures are matched with the path. The prospects of further investigations of structures with circular symmetry are shown.
Solving classification problems of visual evoked potentials for the brain-computer interfaces
Authors: Bulanov V A , Zakharov A V , Chaplygin S S
Published: May 2020

Development of the electroencephalogram-based neurocomputer interfaces requires application of the efficient algorithms for signal analysis. One of the methods of neurocomputer interface development is based on using single visual evoked potentials for characteristics control. However, it is a difficult task, requiring a combination of various methods of signal processing such as Blind Source Separation method, machine learning method and other modern mathematical and computational tools. In this paper, we drew a comparison between various classifiers for the visual evoked potentials recognition problem. The electroencephalogram records analyzed in this paper were published in the public domain.
Technologies and applications for the support of tourism in Krasnoyarsk region
Authors: Nozhenkov Alexander , Korobko Alexey
Published: May 2020

In this article we describe modern information technologies and applications for the support of tourism in Krasnoyarsk region. Applications provide services for registration of tourist groups and control of their travel. All information is automatically sent to the Territorial center of monitoring and forecast of emergencies, as well as to rescue and emergency services. The software is developed in form of a mobile application for tourists and online web-system for the emergency services.
Algorithms and methods of image classification for automated medical systems
Authors: Kovalev I V , Shelomentseva I G , Yakasova N V , Voroshilova A A
Published: May 2020

Modern medicine in the diagnosis of diseases increasingly relies on the use of automated image recognition systems. Automation is of particular importance in the diagnosis of socially significant diseases, when the quality and speed of diagnosis is important. The pathology processes imposes certain restrictions on the methods used, which are associated both with image quality and with the speed of analysis. The article discusses the algorithms and methods for classifying medical images as the basis for automated diagnostic systems; Criteria for choosing among them those methods that satisfy the requirements of the task are determined. Based on a comparison of compliance with the criteria of the methods, neural network methods were selected: a neuro-fuzzy network, a convolutional neural network, and self-organizing maps.
The role of digital technologies in economic development
Authors: Magomedov I A , Murzaev H A , Bagov A M
Published: May 2020

This work is focused on the main aspects of the development of the digital economy. The following work looks at the role of digital technologies in the economic development of modern society. The largest companies in the world influencing the development of the digital economy are considered and the influence of digital technologies on the attitude of society to the economy are also covered.
Industrial and ecological safety analysis for modeling oil and petroleum products spills in the Arctic waters of the Kola Bay
Authors: Katansky A A , Minchenok E E , Zhuravleva N G , Aleksandrova Ye Yu , Trotsenko A A
Published: May 2020

The paper analyses the industrial safety of the coastal and water areas of the Kola Bay of the Barents Sea when modeling the spill of oil or petroleum products. It gives a brief description of the methods and stages of liquidation of oil spills in the water and coastal areas as well as the main causes of accidents. It presents the results of physical and mathematical calculations in theoretical modeling of oil and petroleum products spills, namely: fire risk analysis, calculation of the minimum amount of combustible substance with partial destruction of the tank, calculation of probable areas of hazard boundary during an accident at the pump station, results of calculating the probability of explosion at the pumping station, and individual, collective and social risks. The most likely scenario is an event with partial depressurization (the probability will be 3.9·10−5 1/year): partial depressurization of the tank with liquid oil or petroleum products → oil slick formation → oil slick fire → personnel and equipment present in the hazardous area → exposure of people to thermal radiation. It was found that a minimum of 1182 kg of spilled crude oil is required for uncontrolled combustion to occur with an intensity of thermal radiation of not more than 4.2 kW/m2 m. The time to reach the maximum volumetric average temperature (894 K) in an accident at the pumping station is 136.8 minutes. In these calculations, the individual risk Rind = 3.31·10−5 1/year exceeds the regulatory standard, which shows an urgent need to reduce this risk. The collective risk is: Rcol total = 1.98·10−4 persons/year. Regarding the social risk, we can conclude that the minimum number of injured people will be three in case of an accident at the pump station or during the spill of oil or petroleum products into the Kola Bay, taking into account the fire development. The presented theoretical accident models will reduce the risk of major accidents involving petrochemical pollution of environmental objects, thereby preventing environmental damage, and the problem of the management of large oil spills at various facilities and technological systems of industrial enterprises will be solved.
Theoretical framework of the polymer waste thermal degradation
Authors: Petrov S K , Patrusheva T N , Matveev P V , Logunova T V
Published: May 2020

The article provides a theoretical analysis of the pyrolysis of polymer waste. The main products of pyrolysis are considered. The thermal degradation of polymers was studied depending on the composition of the materials. The main factors affecting the product distribution of pyrolysis of waste plastics are determined. Gaseous medium in the pyrolysis chamber plays a significant role in the process. The operating conditions of the pyrolyser are considered. The use of pyrolysis makes it possible to significantly reduce the amount of solid waste and increase energy savings without harming the environment and human health.
Modernization of gas treatment equipment from pollutants in alumina production
Authors: Shepelev I I , Kiryushin EV , Pilyaeva O V , Eskova E N
Published: May 2020

In this paper, it is the previous system of gas treatmenton sintering furnaces used at JSC “RUSAL Achinsk”, consisting of a dust chamber and electro filters, did not provide the necessary treatment degree. Old four-field electro filters were not effective and required constant replacement and adjustment of electrode systems and shaking mechanisms. Shown that the modernization of gas treatment equipment in alumina production reduces the emissions of polluted substances into the air. The introduction of technical solutions for modernization of obsolete and worn-out electric filters to more modern and efficient five-layer electro filters increases the degree of gas treatment from sintering furnaces from inorganic dust. The introduction of an additional stage of “wet” gas treatment on sintering furnaces in scrubbers has been confirmed by industrial tests, while ensuring high efficiency of gas treatment from fine-disperse dust. When using sub-sludge water as an irrigation liquid at the stage of “wet” gas treatment, it was not necessary to build additional treatment facilities, since the modernization project provides for its subsequent return to the hydrochemistry shop for technological needs.
Logic-sense model of primary oil processing plant safety assurance
Authors: Vakulenko M V , Zharinova N V
Published: May 2020

Safety of oil refining processes, their further technical improvement depend on how soon effective methods of information processing will be found, generalized schemes of reflection of the main dangers of these processes. Modeling of oil refining processes takes an important place in the study of safety issues. The results obtained are the basis for the subsequent systematization of the conditions for the occurrence of accidents and the systematic synthesis of measures to prevent and (or) localize them, eliminate the consequences (in case of occurrence) and reduce possible damage. The proposed model gives a clear idea to the production personnel of the main risks of the primary oil processing process, the consequences of accidents and the main directions of reduction of the plant risk.
Calculation of transition processes in stabilized power sources on the basis of a single-phase serial current inverter
Authors: Umarov Sh B , Rakhmatov D D
Published: May 2020

In article on the basis of an operational method the design procedure of transients duple key of converters of constant pressure in constant pressure with adjustable size of target pressure is offered. Are recived recurrent parities for required currents and pressure which allow to make calculation of transitional process at change of entrance pressure, change of loading and also at their simultaneous change to settle an invoice transients at change of loading. Also results calculation of transitional process in the form of time diagram’s are presented.
Investigation of the dependence of small rivers on the state of bottom sediments by mathematical methods
Authors: Nafikova E V , Dorosh I V , Alexandrov D V
Published: May 2020

Emergency inflow of contaminants into river waters, construction of various hydraulic engineering structures can have an adverse impact on the river ecosystem. Water quality assessment is necessary for operative water resources management, development of engineering solutions for water streams rehabilitation. In this work, application of genetic algorithms for selection of significant indicators of bottom sediments quality for water quality indicators of small rivers in the Republic of Bashkortostan (Russia) has been tested. Selection of significant parameters for indicators of water quality of small rivers was conducted from input parameters: hydrochemical indicators of water quality, indicators of quality of bottom sediments.
Thermal and material balances of the synthesis of PE block copolymers
Authors: Pliushchev V V , Nazarova M A , Bronskaya V V , Aminova G A , Manuyko G V , Shaikhetdinova R S , Guzaerov A M , Kharitonova O S
Published: May 2020

The complex two-phase model based on the well-mixed and two-phase models is presented. The profiles of concentrations and temperatures in microparticles are obtained. The average concentrations and temperatures at the active sites of the catalyst are determined. Heat exchange efficiency on the basis of temperature dependence on technological parameters was studied.
Monitoring of technogenic pollution of soil in the region
Authors: Zhichkina L N , Nosov V V , Zhichkin K A , Starikov P V , Vasyukova A T , Smirnova Z A
Published: May 2020

The purpose of the study is to conduct monitoring of technogenic pollution of soil in the Samara region. The objectives of the study are to identify the sources of technogenic pollution of soil, to analyze the minimum and maximum concentrations of heavy metal on long-term observation plots and background plots, to assess the average and the maximum values of total petroleum hydrocarbons (TPH) in soil of observed land plots. The allowable concentration levels of heavy metals (manganese, lead, cadmium, copper, nickel and zinc) in the soil of the Samara region are not exceeded. Mean heavy metal concentrations in soil did not exceed the maximum permissible concentration (MPC) and the approximate permissible concentration (APC) and was 0.1-0.6 MPC (APC). The maximum concentration of metals in soil was 0.1-0.9 MPC (APC). However, the obtained results were higher than background concentrations of metals. The mean concentrations of aluminium exceeded the background levels by a factor of 3.4-6.7. The maximum concentrations of aluminium in soil was observed in the area of the Samara metallurgic plant (ZAO ‘Arconik’) and was 9.2 of background.
Study of shrinkage of heat storage materials for building envelope structures
Authors: Aimbetova Indira , Suleimenov Ulanbator , Ristavletov Raimberdy , Baigenzhenov Omirserik
Published: May 2020

The article presents the results of thermophysical properties developed by the authors of heat storage materials for building envelope structures. Based on the results obtained, the materials obtained by mixing individual n-alkanes are distinguished by stable thermo-physical characteristics. Results of shrinkage of the developed heat storage materials depending on the temperature during crystallization and expansion during melting. Several shrinkage peaks and two heat release peaks were determined during crystallization and phase transition, which explains that the shrinkage coefficient curves and heat release graphs do not coincide. This is due to the complexity of the chemical composition of commodity paraffin, which contains other groups of hydrocarbons along with n-alkanes. The dependence of shrinkage of heat storage materials on temperature is obtained and their shrinkage coefficients from temperature are analyzed. Developed heat storage materials with a melting point of 250C provide energy savings by increasing the heat capacity of building envelope structures and can be used in the design of energy-efficient buildings.
Calculation of geometric parameters of diesel fuel ignition flares
Authors: Likhanov V A , Lopatin O P , Vylegzhanin P N
Published: May 2020

The fuel flare in the gas-diesel cylinder is the main source of ignition of the methane-air mixture, so the effective combustion of fuel depends on the processes that occur in it when vaporized fuel particles penetrate into the air and form a fuel-air mixture. Thus, the consideration of the parameters and structure of the fuel phase allows us to approach the analysis of the interaction between the methane-air environment and fuel particles, as well as the problems associated with the formation and burning of soot particles in the form of gas diesel.
Passenger gas diesels to preserve the city’s ecology
Authors: Likhanov V A , Lopatin O P , Vylegzhanin P N
Published: May 2020

Today, one of the main tasks of manufacturers of automobiles and mobile power tools is to increase the efficiency of using motor fuels in internal combustion engines while reducing the aggressiveness of toxic components contained in exhaust gases. The paper deals with the main aspects of converting diesels to work on the gas-diesel cycle and presents the results of upgrading a city passenger bus with a modified power system for working on natural gas.
Innovative development technologies of oil and gas industries
Authors: Kiseleva O N , Kulbyakina A V , Ozerov N A
Published: May 2020

Development of oil and gas industries on the base of innovative trends is indicator of sustainable development of the economy of any state. Advancement of innovative trends in the development of the Russian oil and gas industry is the only way to preserve and hold favorable positions on the home and international markets. The authors propose to apply an integrated approach to the design and implementation of innovative development projects at oil and gas enterprises. First, oil and gas enterprises should widely introduce a wide range of innovative technologies with a high potential for internal reserves. Implementation of innovative technologies by empowerment of the energy resources allows for significant economic benefits and upgrading the efficiency of an enterprise within a short term. Another aspect of the problem is related with supporting innovation technologies interconnected with managerial technologies or managerial innovations being the changes aimed at providing a favorable environment for the outcome of innovative technologies. Creation of a favorable management environment as the basis in innovative processes is one of the key factors for successful development. The proposed solution will contribute to innovative development of domestic enterprises and the Russian economy as a whole.
Synthesis of a zinc oxide/graphene hybrid material by the direct thermal decomposition of oxalate
Authors: Little Daniel J , Pfund Jacob D , McLain Avery A , Sporie Jacqueline A , Lantvit Sarah M , King Seth T
Published: May 2020

Hybrid materials of zinc (II) oxide (ZnO) nanocrystals and graphene are of current interest due to their cheap, Earth-abundant composition, low toxicity, and varied applications in photocatalysis, sensing, and electronics among others. We have developed a novel methodology for the synthesis of such materials utilizing the thermal decomposition of zinc (II) oxalate in solid-state solution with graphene nanoplatelets. Although the procedure simply involves precursor mixing and heating, electronic interaction between the ZnO and graphitic phases is spectroscopically observed in the hybrid material—beyond that of a homogeneous mixture of ZnO and graphene—via powder XRD, XPS, and ATR-IR spectroscopy. The synthetic method employed can be easily tuned for the desired hybrid product stoichiometry, and is easily industrially scalable with minimal chemical waste products.
Mechanical enhancement of ripples and dimples in CaCO3/low-density unsaturated polyester resin composites
Authors: Wang Ruru , Wang Xiaojun
Published: May 2020

Incorporation of different fine grain calcium carbonate into CaCO3/low-density unsaturated polyester resin (LDUPR) composites was studied and evident mechanical enhancement of CaCO3 on composites was investigated. Preliminary experiment results indicated that proper content of CaCO3 was less than 30.00 phr (parts per hundreds of resin), suitable preparation temperature range was from 72.0 °C to 80.0 °C, and initiator content was 1.80 phr. Optimal preparation conditions of CaCO3/LDUPR samples were obtained with the presence of 25.00 phr CaCO3 and 2.50 phr NH4HCO3 at 76.0 °C based on preliminary experiments. The lowest apparent density of A-CaCO3/LDUPR composite was 0.53 ± 0.02 g · cm−3 with a compressive strength of 20.27 ± 0.51 MPa · g−1 · cm3, and the highest specific compressive strength of the sample was 38.25 ± 1.43 MPa · g−1 · cm3. It is attributed to the hindrance to cross-linking between unsaturated polyester and styrene, and to the decrease of exothermic heat of the polymerization, which was caused by the existence of CaCO3. Unusual matrix microstructure with regular ripples and dimples formed by CaCO3, and the particular mechanical enhancement of regular ripples and dimples in composites were explored. ‘CaCO3 reefs’ concept, reefs-induced ripples, dimples of streams flowing, and resolution of external force with major force further being consumed models comprised the regulated mechanical enhancement of CaCO3 in CaCO3/LDUPR composites. This particular polymerization retarding and mechanical strengthening were obvious for the finest grain CaCO3.
Tumor microtubes connect pancreatic cancer cells in an Arp2/3 complex-dependent manner
Authors: Latario Casey J. , Schoenfeld Lori W. , Howarth Charles L. , Pickrell Laura E. , Begum Fatema , Fischer Dawn A. , Grbovic-Huezo Olivera , Leach Steven D. , Sanchez Yolanda , Smith Kerrington D. , Higgs Henry N.
Published: May 2020

We identify tumor microtubes (TMTs) and cell-substrate protrusions (CSPs) in a pancreatic cancer line, in cell culture, tumor models, and a subset of primary human tumors. TMTs and CSPs emanate from the lateral plasma membrane and contain actin filaments, microtubules, and cytokeratin. Arp2/3 complex drives two distinct TMT assembly mechanisms.
Performance of Electrocardiographic Criteria for Echocardiographically Diagnosed Left Ventricular Hypertrophy in Chinese Hypertensive Patients
Authors: Wang Dian , Xu Jian-Zhong , Zhang Wei , Chen Yi , Li Jian , An Yinghua , Bian Rui , Wang Ji-Guang
Published: May 2020

BACKGROUND

Performance of electrocardiographic (ECG) criteria for echocardiographically diagnosed left ventricular hypertrophy (LVH) in Chinese hypertensive patients is not well known. We investigated the accuracy of various ECG criteria for the diagnosis of the echocardiographic LVH according to the new cutoff values of left ventricular mass (LVM) index (>115 g/m2 for men and >95 g/m2 for women) in Chinese hypertensive patients.

METHODS

Our study included 702 consecutive hypertensive inpatients including 92 (13.1%) concentric and 121 (17.2%) eccentric LVH on standard echocardiography. Diagnostic accuracy of 7 ECG criteria was evaluated by calculating sensitivity and specificity and by using the receiver operating characteristic curves.

RESULTS

The ECG criteria for the detection of the echocardiographically defined LVH had a sensitivity of 15%–31.9% and specificity of 91.6%–99.2% overall, 20.7%–43.5% and 91.6%–99.2% concentric, and 7.4%–23.1% and 91.6%–99.2% eccentric. ECG diagnosis of LVH defined as the positive diagnosis of any of 4 ECG criteria including Sokolow–Lyon voltage, Cornell voltage, Cornell product, and RavL voltage had a sensitivity of 54% and specificity of 86.3% overall, 71.7% and 86.3% concentric, and 40.5% and 86.3% eccentric. After adjustment for confounding factors, various ECG criteria were significantly correlated with LVM, with standardized β coefficients from 0.20 to 0.39 (P < 0.001) and the highest coefficient for the Cornell product criterion.

CONCLUSIONS

All ECG LVH indexes had low sensitivity and high specificity in Chinese hypertensive patients. Combination of 4 or all ECG criteria might improve sensitivity without any loss of specificity.
Comparison of microbiome samples: methods and computational challenges
Authors: Comin Matteo , Di Camillo Barbara , Pizzi Cinzia , Vandin Fabio
Published: May 2020

The study of microbial communities crucially relies on the comparison of metagenomic next-generation sequencing data sets, for which several methods have been designed in recent years. Here, we review three key challenges in the comparison of such data sets: species identification and quantification, the efficient computation of distances between metagenomic samples and the identification of metagenomic features associated with a phenotype such as disease status. We present current solutions for such challenges, considering both reference-based methods relying on a database of reference genomes and reference-free methods working directly on all sequencing reads from the samples.
Normal tissue content impact on the GBM molecular classification
Authors: Madurga Rodrigo , García-Romero Noemí , Jiménez Beatriz , Collazo Ana , Pérez-Rodríguez Francisco , Hernández-Laín Aurelio , Fernández-Carballal Carlos , Prat-Acín Ricardo , Zanin Massimiliano , Menasalvas Ernestina , Ayuso-Sacido Ángel
Published: May 2020

Molecular classification of glioblastoma has enabled a deeper understanding of the disease. The four-subtype model (including Proneural, Classical, Mesenchymal and Neural) has been replaced by a model that discards the Neural subtype, found to be associated with samples with a high content of normal tissue. These samples can be misclassified preventing biological and clinical insights into the different tumor subtypes from coming to light. In this work, we present a model that tackles both the molecular classification of samples and discrimination of those with a high content of normal cells. We performed a transcriptomic in silico analysis on glioblastoma (GBM) samples (n = 810) and tested different criteria to optimize the number of genes needed for molecular classification. We used gene expression of normal brain samples (n = 555) to design an additional gene signature to detect samples with a high normal tissue content. Microdissection samples of different structures within GBM (n = 122) have been used to validate the final model. Finally, the model was tested in a cohort of 43 patients and confirmed by histology. Based on the expression of 20 genes, our model is able to discriminate samples with a high content of normal tissue and to classify the remaining ones. We have shown that taking into consideration normal cells can prevent errors in the classification and the subsequent misinterpretation of the results. Moreover, considering only samples with a low content of normal cells, we found an association between the complexity of the samples and survival for the three molecular subtypes.
The Prospect of Regulatory Alignment for an Interconnected Capital Market between the United Kingdom and China: A Takeover Law Perspective
Authors: Lee Joseph , Bao Yonghui
Published: May 2020

The United Kingdom (UK) and China have launched the London–Shanghai Stock Connect Scheme to achieve an integrated capital market. In this article, the takeover market is used as an example to examine the extent to which regulatory alignment between the UK and China is possible. The focus is on the role of financial intermediaries in the two markets and how they may influence the governance model of the transfer of corporate control by an open offer to the shareholders of the target company (a takeover bid). This article argues that without regulatory alignment such an integrated market is unlikely to be realized. There are differences between the UK and China in the economic model, ownership structure, and institutional arrangements, which have been reflected in the differences in interests served by takeover law in the two regimes. The design of the framework for takeover law in the UK empowers financial market participants, so as to attract capital to the London markets. In contrast, China’s takeover law is mainly aimed at facilitating industrial restructuring and creating globally competitive national companies (national champions). Hence, the UK’s shareholder-centred takeover model, with a strong focus on financial intermediaries and international investors, would not be easily replicated in China. However, the UK model could provide lessons for China to develop its takeover market—that is, further its market structure reform, develop independent financial intermediaries, and also attract an increasing number of investors.
Inferring Risk Perceptions and Preferences Using Choice from Insurance Menus: Theory and Evidence
Authors: Ericson Keith Marzilli , Kircher Philipp , Spinnewijn Johannes , Starc Amanda
Published: May 2020

Demand for insurance can be driven by high risk aversion or high-risk. We show how to separately identify risk preferences and risk types using only choices from menus of insurance plans. Our revealed preference approach does not rely on rational expectations, nor does it require access to claims data. We show what can be learned non-parametrically about the type distributions from variation in insurance plans, offered separately to random cross-sections or offered as part of the same menu to one cross-section. We prove that our approach allows for full identification in the textbook model with binary risks, and extend our results to continuous risks. We illustrate our approach using the Massachusetts Health Insurance Exchange, where choices provide informative bounds on the type distributions, especially for risks, but do not allow us to reject homogeneity in preferences.
Between Love and Coercion: Queer Desire, Sexual Barter and the Holocaust
Authors: Hájková Anna
Published: May 2020

In analysing a forced relationship between two women, a German guard and a Jewish Czech prisoner in a Hamburg concentration camp, this article uses queer Holocaust history to explore sexual barter, sexual violence, victim agency, and the rules of prisoner society. It also makes a plea for a departure from normativity in thinking about the Holocaust and for the inclusion of marginalized voices.
Understanding the Role of Incentive Salience in Sexual Decision-Making
Authors: Lynch Kathleen S , Ryan Michael J
Published: May 2020

Synopsis

In the search for understanding female sexual decision-making, progress has been made in uncovering a variety of perceptual biases and most of these concern the animal’s sensory biology and cognitive processes. We are now poised to dig deeper into the female’s decision-making and ask if incentive salience, which plays a role in all types of appetitive behaviors, also influences a female’s “taste for the beautiful.” The incentive salience hypothesis suggests that dopamine assigns value or salience to objects or actions. After value is assigned to all potential actions, an action selection system then chooses among potential options to select the most valuable action. In this view, dopamine stimulates reward-seeking behavior by assigning incentive salience to specific behavioral actions, which in turn, increases pursuit and focus on objects or stimuli that represent the valuable action. Here, we apply this framework to understand why females are compelled to respond maximally to some male courtship signals over others and how this process may reveal a female’s hidden mate preferences. We examine studies of dopamine and the mesolimbic reward system because these may play a role in expanding the female’s perceptual landscape for novelty in male courtship signals and establishing novel hidden preferences. We review three avenues of research that may identify signatures of incentive salience in females during sexual decision-making. This review includes studies of dopamine agonist or antagonist administration in females during mate choice or partner preference tests, measures of neural activity in dopaminergic neural circuits during mate choice or partner preference tests, and social regulation of dopamine in females when entering reproductive contexts and/or exposure to mate signals. By applying the incentive salience hypothesis to female reproductive decision-making, it redefines how we see the female’s role in sexual encounters. Females cannot be considered passive during reproductive encounters; rather they are seeking sexual encounters, particularly with males that tap into their perceptual biases and initiate a reward-seeking response. Incentive salience applied to reproductive behavior requires considering females as viewing sexual stimuli as rewarding and initiating action to seek out this reward, all of which indicates females are driving sexual encounters.