bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship Between Insulin Sensitivity and β-Cell Secretion in Nondiabetic Subjects with Rheumatoid Arthritis
Authors: Tejera-Segura Beatriz , López-Mejías Raquel , de Vera-González Antonia M. , Jiménez-Sosa Alejandro , Olmos José M. , Hernández José L. , Llorca Javier , González-Gay Miguel A. , Ferraz-Amaro Iván
Published: October 2018

Objective.

In nondiabetic healthy individuals, insulin secretion and sensitivity are linked by a negative feedback loop characterized by a hyperbolic function. We aimed to study the association of traditional insulin resistance (IR) factors with insulin secretion and sensitivity, and to determine whether the hyperbolic equilibrium of this relation is preserved in patients with rheumatoid arthritis (RA).

Methods.

This was a cross-sectional study encompassing 361 nondiabetic individuals: 151 with RA and 210 controls. Insulin, C-peptide, and IR indices by homeostatic model (HOMA2) were assessed. A multivariable analysis was performed to evaluate the differences in the correlation of traditional IR-related factors with glucose homeostasis molecules, as well as IR indices between patients and controls. Nonlinear regression analysis was used to assess the hyperbolic relation of insulin sensitivity and secretion.

Results.

HOMA2-IR indices were higher in patients with RA than controls. Hepatic insulin extraction, as assessed by the insulin:C-peptide molar ratio, was lower in patients with RA after multivariable analysis (0.08 ± 0.02 vs 0.14 ± 0.07, p < 0.001). Traditional IR-related factors showed significantly lower adjusted correlation coefficients with IR indices in patients with RA. The association between insulin sensitivity and secretion showed a different hyperbolic relation in patients with RA: the variability explained by the curve was lower in RA (nonlinear r2= 0.845 vs r2= 0.928, p = 0.001) and β coefficients (−0.74, 95% CI −0.77 to −0.70 vs −1.09, 95% CI −1.17 to −1.02, ng/ml, p < 0.001) were different in RA.

Conclusion.

The traditional factors associated with IR in healthy individuals are less related to IR in patients with RA. Insulin sensitivity and secretion yield a different hyperbolic equilibrium in RA.
Indigenous practices in poultry farming using maggots in western Burkina Faso
Authors: Sanou A.G. , Sankara F. , Pousga S. , Coulibaly K. , Nacoulma J.P. , Kenis M. , Clottey V.A. , Nacro S. , Somda I. , Ouédraogo I.
Published: October 2018

The exploitation of insects such as saprophagous fly larvae for poultry nutrition is getting prominence in many African countries. In the framework of a participatory research, a survey was carried out in Burkina Faso to assess the present use of fly larvae and other feed inputs in traditional poultry farming, to identify traditional methods associated with fly larvae production and to gather information on the organic wastes that could be used locally by farmers to produce fly larvae. A questionaire was randomly administered to 360 poultry farmers in 12 villages and 2 regions (Boucle du Mouhoun and Hauts-Bassins) in Burkina Faso. Nearly 15% of the respondents mentioned that they also use fly larvae at least occasionally. Fly larvae are either produced by exposing substrates to naturally occurring flies, in which case larvae are obtained after three to 14 days, depending on the species, or directly collected in organic wastes. Housefly (Musca domesticaL.) was the most commonly used fly species but black soldier fly (Hermetia illucens(L.)) was also cited by some farmers. Over 30 organic wastes of animal or plant origin were cited by farmers as substrates that can attract adult flies and allow the development of their larvae. Farmers who have already produced fly larvae cited 25 potential substrates that can be used either alone or mixed with attractants. Information was gathered on the production techniques and their constraints, among which the lack of availability of suitable substrates. The study highlighted the potential of maggots as protein feed in traditional poultry farming but also the need to develop sustainable, efficient and safe production methods. The survey revealed the need to determine the most productive substrates for maggot rearing and safe substrates for poultry health. There are also indigenous practices that can be improved to increase maggot production.
Correlates and Predictors of Stigmatization of Patients With Mental Illness Among Nursing Students
Authors: Abuhammad Sawsan , Hatamleh Reem , Howard Kimberly , Ahmad Muayyad M.
Published: October 2018

The purpose of the current study was to explore knowledge of, attitudes about, and perception of stigma among nursing students in relation to mental illness, and to identify the predictors of stigma toward patients with mental illness based on nursing students' characteristics, knowledge, and attitude. A cross-sectional survey was conducted on 169 participants from a university in Jordan. The regression model predicted a relatively moderate proportion of variance in stigma perception. Significant predictors in the model were family income, father's educational level, and experience with mental health patients. Findings of the current study showed that undergraduate nursing students who had experience with patients with mental illness hold relatively positive perceptions toward mental health patients. Enhancing the content of nursing curriculum regarding issues related to patients with mental illness could help students develop better assessment skills, have more positive attitudes, and gain more accurate knowledge about mental illness. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(1), 43–51.]
Professional Boundaries of Nursing Staff in Secure Mental Health Services: Impact of Interpersonal Style and Attitude Toward Coercion
Authors: Lambert Katie , Chu Simon , Turner Polly
Published: October 2018

The current study explored the impact of nursing staff members' interpersonal style and attitudes toward coercion on the management of their professional boundaries. Researchers predicted that a combination of a particular interpersonal style, a specific attitude toward coercion, and self-reported engagement in boundary-crossing behavior would be associated with particular styles of boundary management as outlined by Hamilton's Boundary Seesaw Model. Sixty-three nursing staff members in secure inpatient mental health services completed measures of boundary management, boundary crossings, attitude toward coercion, and interpersonal style. Regression analyses showed that a submissive interpersonal style and fewer boundary-crossing behaviors were associated with a pacifier boundary management style. In contrast, a pragmatic attitude toward coercion predicted a negotiator style of boundary management. The regression model for controller boundary management style was not significant. Findings are explored, along with their impact and implications for research and practice. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(2), 16–24.]
Examination of Executive Function and Social Phobia Among Female College-Aged Students With Celiac Disease
Authors: Arnone Jacqueline M. , Rizzolo Denise , Conti Richard P.
Published: October 2018

Celiac disease (CD) is a T-cell mediated genetically inherited autoimmune disease affecting approximately 1% of the population. Research suggests that CD impacts executive functioning (EF) and social phobia (SP). However, most of the literature in this area focuses on age groups outside of the traditional college age range and has never measured EF and SP together. This descriptive study compared traditional age female college students with CD to age- and sex-matched college students without CD on measures of EF and SP. Participants completed the Behavior Rating Inventory of Executive Function–Adult version (BRIEF-A), the Social Anxiety Questionnaire for Adults–Short Form (SAQ-A30), and a demographic questionnaire. Results indicated that participants with CD reported lower grade point averages; scored lower on BRIEF-A measures of working memory, planning/organization, and organization of materials; and scored higher on SAQ-A30 measures involving interactions with the opposite sex and strangers. Implications for nursing practice are discussed. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(2), 25–34.]
Interrelationships Among Resilience, Posttraumatic Stress Disorder, Traumatic Brain Injury, Depression, and Academic Outcomes in Student Military Veterans
Authors: Shackelford Jo L. , Smith Lynette S. , Farrell C. Thomas , Neils-Strunjas Jean
Published: October 2018

Resilience, depression, posttraumatic stress disorder (PTSD), and traumatic brain injury (TBI) are important factors to consider as student military Veterans work to reintegrate into society. The impact of these factors on academic success is not fully understood, but is important for rehabilitation professionals, student advisors, and counselors. The current study examined the impact of resilience, depression, PTSD, and TBI on student Veteran academic outcomes, and whether the amount of student Veterans' military experience moderated the effect of these factors on academic performance. Seventy-seven student Veterans completed measures that assessed resilience, grade point average, academic disruptions, and symptoms of depression, PTSD, and TBI. Path analysis was used to determine the manner in which the variables influenced academic performance. Results indicate that student Veterans should not be viewed as a homogeneous group and their needs differ based on level of military experience. Academic disruption among less experienced Veterans was most associated with symptoms of depression, whereas academic disruption among more experienced Veterans was most associated with symptoms of TBI. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(2), 35–43.]
Leveraging Community Engagement to Develop Culturally Tailored Stress Management Interventions in Midlife Black Women
Authors: Jones Holly J. , Norwood Carolette R. , Bankston Karen
Published: October 2018

Chronic stress is a social health determinant associated with many persistent health conditions and health disparities for midlife Black women. Midlife Black women in the United States are exposed to multiple, competing stressors, increasing their risk for adverse health outcomes. The objective of the current study was to illicit information about the key life stressors experienced by midlife Black women. Focus groups were conducted using a convenience sample of midlife Black women (
N
= 11, age range = 41 to 54 years). Coding and thematic analysis identified four primary sources of stress: workplace, parenting, finances, and social media. Gendered racism and discrimination and life imbalance emerged as underlying stressors linked to the Strong Black Woman persona. This persona prioritizes resilience and self-reliance while suppressing self-care. The stressors identified will inform the development of an intervention and should be considered when providing care for midlife Black women. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(3), 32–38.]
Regional Differences in Body Image Perception Among Young African American Women Living in the United States
Authors: Pickett Stephanie , McCoy Thomas P.
Published: October 2018

The current study examined regional differences in body image perceptions and body mass index (BMI) among young African American women. Three hundred forty-one African American women, 18 to 40 years old, living in three regions of the United States were recruited. Pulver's Figure Rating scale was used to identify body image perceptions. Weight and height were measured for BMI calculation. Analysis of covariance was used to examine body image perception differences. The sample mean age was 27.8 years and mean BMI was 30.3 kg/m
2
. Participants' body image perceptions were significantly smaller among participants living in the Northeast compared to the Southeast (mean difference = −0.65, 95% confidence interval [CI] [−1.18, −0.11],
p
= 0.018) and Midwest (mean difference = −0.64, 95% CI [−1.16, −0.12],
p
= 0.015). No significant differences in BMI were found among regions (
F
(8,318) = 1.17,
p
= 0.314). Clinical implications of these findings are discussed. [
Journal of Psychosocial Nursing and Mental Health Services, 57
(3), 25–31.]
Theoretical and experimental analysis of multifunctional high performance cement mortar matrices reinforced with varying lengths of carbon fibers
Authors: Khushnood R. A. , Muhammad S. , Ahmad S. , Tulliani J. M. , Qamar M. U. , Ullah Q. , Khan S. A. , Maqsom A.
Published: October 2018

An effective scheme to formulate high performance and multifunctional cement based mortar composites reinforced with varying lengths of carbon fibers has been devised. The detailed investigations pertaining to the fracture response of composites in cracks initiation and progression phases, their conducting mechanism and volumetric stability were performed with varying loads of 6mm and 12mm long carbon fibers at two different w/c ratios i.e. 0.45 and 0.50. The experiments concluded that an optimum addition of carbon fibers results in substantial improvement of fracture properties alongside significant reduction in electrical resistivity and total plastic shrinkage. The field emission scanning electron microscopy of the cryofractured specimen revealed crack arresting actions of uniformly distributed carbon fibers through successful crack bridging and branching phenomenon.
Adaptive Node Degree Adjustment Based Power Control Method for Wireless Sensor Networks
Authors: Hu Huang Shui , Zheng Man , Zhang Bang Cheng , Qing Jin Hui
Published: October 2018

Properly adjusting the transmission power of the wireless sensor nodes has shown to be an effective approach to reduce energy consumption and to improve the network reliability. I In this paper, an adaptive Node Degree adjustment based Power Control method for wireless sensor networks (NDPC) is proposed to dynamically adjust the transmission power of the nodes. In NDPC, each node is embedded with a fuzzy neural controller which is used to adjust the target node degree so as to control the communication range properly. The fuzzy neural controller consists of two Fuzzy Inference Systems (FIS). One adopts closed-loop feedback mechanism to adjust the target node degree according to the residual energy. The other adjusts the communication range by a self-learning neural network to control the transmission power based on the target node degree. Consequently, the actual energy consumption of the node is reduced while keeping the desired node degree. Several simulation experiments are conducted to evaluate the performance of NDPC, and the results show that NDPC can reduce the actual energy consumption as well as extend the network lifetime.
Applying a Model Driven Architecture Approach: Transforming CIM to PIM Using UML
Authors: Betari Oualid , Filali Saida , Azzaoui Amine , Boubnad Mohamed Amine
Published: October 2018

Over the last few years, as they evolve with business needs and technology, enterprises are faced with the need to adapt their business processes to work in open settings. In such settings, the automation and the interoperability of business process and applications become a key concern. The Model Driven Architecture (MDA) is introduced as an approach to cope with this challenge. MDA specifies four levels of abstraction, most of the existing studies focus on modeling and transforming the Platform-Independent Model (PIM) to Platform-Specific Model (PSM) levels, while the more conceptual level, the Computation-Independent Model (CIM) is often presumed as present and is not further studied. In this paper, we propose an approach for transforming a CIM into a PIM using the core modeling concepts of the Unified Modeling Language (UML). One important characteristic of this approach is that it provides a method to capture and describe the requirements of the business process using a use cases model. The other important characteristic is proposing an architecture of the PIM based on the classes model. The execution of the transformation is programmed by the Query View Transformation (QVT) language.
Volunteer Observer Bias and Sharp-Tailed Grouse Lek Counts in the Upper Midwest
Authors: Corace R. Gregory , Weiss Shelby A. , Shartell Lindsey M.
Published: October 2018

For most species of prairie grouse Tympanuchus spp. standardized monitoring protocols do not exist across adjoining jurisdictions. For instance, researchers monitor relatively small and disjunct populations of prairie sharp-tailed grouse Tympanuchus phasisanellus campestris in Michigan, Wisconsin, and Minnesota using different lek count protocols. Some of these state-led monitoring efforts include the widespread use of volunteers who conduct lek counts without training. To facilitate discussions regarding standardizing sharp-tailed grouse lek count protocols in the Upper Midwest and elsewhere, we quantified the magnitude of differences in data arising from lek counts conducted by paired observers and examined factors potentially associated with observer bias (e.g., training type, use of optical equipment, experience). During 2010–2015, 44 unique pairs of formally trained volunteers in the Upper Peninsula of Michigan performed 93 counts at one lek while controlling for weather, distance to the lek, and the timing of observations. All counts consisted of six 1 min observations over 1 h. At three leks in northeastern Minnesota during 2015, nine pairs (consisting of an individual new to lek counts and a more experienced biologist) performed 21 lek counts using the same protocols, but without formal training for novice observers. Across all years and all sites, our results consistently indicated more agreement in data for dancing birds than nondancing birds. Overall, the mean ± SE difference between paired observers for total birds (dancing and nondancing combined) was 1.05 ± 0.09 in Michigan and 0.37 ± 0.08 in Minnesota. Generalized linear models indicated that the use of optical equipment and training type for dancing birds and training type for nondancing birds were significant factors that improved data agreement in Michigan. In Minnesota, models indicated that experience level (number of surveys performed) of the technician or volunteer did not affect count differences for dancing birds or nondancing birds. We contend that using behavior as a proxy for sex can bias lek count data for sharp-tailed grouse. We suggest lek count protocols in the Upper Midwest be simplified and standardized. Specifically, we suggest that observers report the total number of observed birds (regardless of behavior) and that protocols establish a set duration of observation. We also suggest that the use of optical equipment be required and that training be mandatory.
Reflexões sobre a memória na ficção de Machado de Assis e na obra de Paul Ricoeur
Authors: Chaves Renato Novaes , Marinho Maykon Dos Santos , Reis Luciana Araújo dos
Published: October 2018

O objetivo desta pesquisa é analisar a concepção de memória na ficção romancista: Memórias Póstumas de Brás Cubas, de Machado de Assis, e na obra A Memória, A História e o Esquecimento, de Paul Ricoeur; bem como apresentar algumas singularidades da referida obra machadiana à luz da teoria deste último. O corpus constituiu-se em bases bibliográficas, sendo que as fontes secundárias foram obtidas a partir do romance de Machado de Assis e da obra de Ricoeur. Procedeu-se a análise crítica dos livros por meio de uma revisão narrativa. Os resultados evidenciaram que Ricoeur entende a memória como uma experiência que o indivíduo tem de ressignificar ou representar; a memória é tratada e discutida na perspectiva de atribuir um dever de legitimação. Em Machado de Assis, tem-se uma descrição qualitativa da memória como uma experiência vivida. Ele revela diferentes aspectos da memória, uma vez que as lembranças são usadas de um modo muito dinâmico. As singularidades mostraram que em Brás Cubas a memória, empregada enquanto recurso artístico, revela-se autêntica, pois a lembrança evocada pelo protagonista confere à memória um significado de verdade.
Diferenças salariais por gênero no setor público brasileiro no período 2002-2015: magnitude, evolução e determinantes
Authors: Vaz Daniela Verzola
Published: October 2018

Este trabalho estuda o comportamento do hiato de rendimentos por sexo no setor público brasileiro entre 2002 e 2015. Emprega-se a metodologia de Blinder-Oaxaca para decompor o diferencial salarial bruto na parcela explicada pelas características da mão de obra ― como as diferenças nas dotações produtivas médias de homens e mulheres e em seus padrões de inserção ocupacional ― e em um componente residual, derivado dos retornos a essas características. A análise é feita para todas as PNAD no período 2002-2015, porém, é apresentada de forma mais detalhada para 2015. Para esse ano também é empregada a metodologia não paramétrica de Ñopo (2008) para decompor o diferencial salarial. Os resultados mostram que, de acordo com o método de Blinder-Oaxaca, a participação do componente residual no hiato salarial aumentou, passando de 45,3% em 2002 para 55,5% em 2015. A técnica de Ñopo mostrou uma participação de 54% da parcela residual no diferencial de rendimento em 2015. Assim, mesmo após o controle pelas características observáveis dos servidores, subsiste um diferencial por sexo, cuja magnitude não sofreu redução no decorrer do período estudado. Os fatores que mais se destacam na explicação desse diferencial são a idade e a jornada semanal de trabalho dos servidores.
New Concrete for Protection from Radiation in the Urals Based on Natural Fillers
Authors: Rudnov Vasiliy S. , Belyakov Vladimir A. , Galiakhmetov R.T.
Published: October 2018

The most difficult problem of the modern high-tech world is the protection of a living organism from the effects of radiation in the existence of nuclear technology in all areas of daily life. The article considers the problem of finding new effective building materials to protect people and the environment from the threat of the neutron and γ-radiation. Modern radiation-protective materials must have high strength and environmental characteristics of the performances and have a low cost. The authors carried out experimental studies on the development of a new radiation-shielding concrete using natural dunite aggregates from the Urals region. The research included selecting the original components of rational composition and technological characteristics of the concrete mixtures. The results showed its effectiveness compared to traditional granite aggregate used in concrete. On the experimental base of Ural Federal University named after. B.N. Yeltsin the research has shown an increase in efficiency of 1.35-3.0 times the effectiveness of the newly developed protection of electromagnetic radiation to protect against non-ionic and γ-excretions, depending on the energy field.
Optimization of Fine-Grained Concrete Composition in Order to Improve the Quality of Units’ Front Surface
Authors: Goncharova Margarita A. , Simbaev V.V. , Karaseva O.V.
Published: October 2018

In this article, the results of optimizing fine-grained concretes are given. Laboratory tests were conducted to obtain a high-quality front surface of products formed according to two different methods. Special focus was given to the rheological characteristics of concrete mixture which make the biggest impact on the front surface quality class of units produced from modified fine-grained concretes.
Defects of Porous Self-Structured Anodic Alumina Oxide on Industrial Aluminum Grades
Authors: Yuferov Yu.V. , Zykov F.M. , Malshakova E.
Published: October 2018

In this paper, an experimental examination of defects in anodization of aluminum of the industrial grade A7E is presented. A two-step method of anodizing was used in an electrolyte containing 20% wt. % sulfuric acid at 0 ° C at constant voltage. Micro-video recording was carried out in both anodizing stages to examine anodizing process on a micrometer scale, and to determine the corresponding macro-scale effects indicating incorrect anodization process. Macro-scale effects in the form of gas evolution were detected. Subsequently confirmed on the surface of the coating from which it occurred, using scanning electron microscopy. Methods for preparing samples subject to anodization are proposed to reduce the number of defects. The results should lead to industrial implementation of inexpensive and high-quality nanoporous anode materials with a variety of applications.
Investigation into the Effects of High Temperature on Mechanical Properties of Thermal Spray Coatings Applied by Plasma Spraying
Authors: Shafigullin Lenar N. , Ibragimov A.R. , Saifutdinov A.I.
Published: October 2018

C. C. Berndt advanced investigations of mechanical properties of thermal spray coatings under 4-point bending. He found that this investigation method is sensitive to the mechanical properties of thermal spray coatings.This paper contains the detailed investigation results for thermal spray coatings of zirconium dioxide under 4-point bending, i.e. tests of the specimens subjected to spraying at varying conditions and pre-test soaking with the various duration at 1100 °С.It was established how the mechanical properties of thermal spray coatings changed depending on the spraying mode and high temperature soaking. The test results show that the double heat treatment of coatings is more preferable than one-time heat treatment as it make the properties change linearly. It is more easily controllable during operation of the components with thermal spray coating.
Tin Powders Electrodeposition from Choline Chloride Based Ionic Liquid
Authors: Lipkin V.M. , Fesenko L.N. , Lipkin Mikhail S.
Published: October 2018

Possibilities of tin powders obtainment from the choline chloride-ethylene glycol ionic liquid are considered. The tin reduction from an ionic liquid mechanism is confirmed via chronovoltametry, chronopotentiometry, transient potential and impedance spectroscopy methods. Said mechanism includes the trichlorostanite complexes reduction at current densities up to 5 mA / cm2, recovery from a polyanionic adsorbed layer at current densities of 5-12 mA/cm2 and recovery from a mixed layer including polyanions bound and by electrolyte ions at current densities exceeding 12 mA/cm2. Tin ions reduction from the mixed coating layer facilitates forming of encapsulated tin powder particles with shape of symmetrical dendrites. Powders obtainment from an ionic liquid allows to reduce the resulting powder dispersion.
Laser-Spark Modification of the Surfaces of Structural Materials by the Example of St3
Authors: Kuptsov S.G. , Shimov V.V. , Magomedova R.S.
Published: October 2018

The paper considers a technology for hardening construction materials using the hybrid (laser-spark) method by the example of steel St3 using hard alloys (VK8, stellite PR-V3K). A significant (several-fold) increase in the wear resistance of the coatings obtained is shown at resistance to abrasive friction due to the good quality of the coating layer and its microhardness (up to 60 GPa). Optimum modes for electrical spark and laser surface modification are proposed. Some physical and chemical properties of the coatings obtained (thickness, roughness, wear resistance, microhardness), as well as their dependence on the hybrid machining modes, are studied. The prospectivity of applying the hybrid (laser-spark) method for hardening of machine parts in order to increase their resistance to abrasive wear during friction is justified.
Application of Gas-Thermal Coatings on Low-Alloyed Steel Surfaces
Authors: Gerasimova Alla A. , Gorbatyuk Sergey , Devyatiarova Victoria V.
Published: October 2018

In the present scientific work a thickness calculation procedure of an aluminum gas-thermal coating, sprayed on the low-alloyed steel surfaces, in order to provide its effective protection at high temperatures, has been developed. The method is based on the calculations of the diffusion layer thickness with consideration the temperature change on the blank`s surface and on the dependence of the parameter (directly proportional to the diffusion coefficient) on the temperature over the range 700 to 1200 °C.
Modeling Calculation of the Corrosion Rate of Low Carbon Steel in Heat and Power Systems
Authors: Kozlova T.V. , Lipkina T.V. , Lipkin Mikhail S.
Published: October 2018

This article is about electrochemical analysis system of passive films corrosion properties of the thermal power equipment heating surfaces. It was found that forecasting the low carbon steel corrosion rate in thermal power systems is possible based on the multiple regression equations, which includes the amount of silicon oxide and iron hydroxide phases in the films, the fraction of free area and the active component of impedance of the films in the alkaline electrolyte and mercury. Construction of the regression equation should be carried out with the preliminary classification of data on the quantities of the active component of the film impedance of mercury and an alkaline electrolyte.
Efficiency Analysis of the Friction Material for the Wind Turbine Braking System
Authors: Solomin E.V. , Sirotkin E.A. , Kirpichnikova I.M.
Published: October 2018

The paper presents a research in identification of optimal conditions for friction material operation in the wind turbine braking system. The component composition of friction material includes brass (binder material); steel (fibers); iron oxide (fillers); cuprum, graphite and metal sulphides (friction modifier); aluminum (abrasive). The dependence of its frictional characteristics on the operating temperature is presented. We also presented the simulation of several modes of the wind turbine braking system. The most optimal operation mode for the friction material is the wind turbine rotor braking and its retention for 30 seconds, followed by further retention of the wind turbine rotor for 300 seconds after each 4th braking.The temperature of frictional material with these parameters did not exceed 350 oC, though the minimal idling of wind turbine was provided.
Qualimetry Rating of Hot-Rolled Pipes
Authors: Orlov Grigory A. , Orlov A.G.
Published: October 2018

The evaluation quality rating of hot-rolled pipes using complex quality indicators is considered. The weighted averages of arithmetic and geometric complex indicators as well as with probabilistic indicators of access to allowable intervals on the example of oil-grade pipes are compared. It is shown that all the indicators have similar values. A complex rating of the properties of pipes manufactured by current and improved technologies was conducted. The impact of individual indicators on the quality of pipes as a whole was estimated. A comparison of complex indicators of the quality of pipes rolled on two technologies made on the scale of Harrington's desires: the current technology indicator corresponds to a sufficient level of quality in accordance with the normative documents. The indicator of the improved technology corresponds to an acceptable and good level of quality.
The Method and Device for Automated Material Elastic and Proportionality Limits Calculation
Authors: Kuts Vadim V. , Byshkin A. , Khodyrevskaya S.
Published: October 2018

The present article describes the method and devices for material elastic limits and proportionality calculation. This invention is to allow for automation and higher measurement accuracy. Formulas for calculating measurement errors are given. An example of measuring and calculating is described.
The Study of Ultrasonic Relaxation of Residual Stresses of Metal Plates Using Computer Simulation
Authors: Korolev Albert Viktorovich , Balaev A.F. , Korolev A.A.
Published: October 2018

To stabilize the geometric parameters of the elastic plates during production, the "aging" method is used, which has low performance, and as an alternative to which the method of ultrasonic stabilization is developed. The essence of ultrasonic stabilization is to create the elastic strain applied via the static load in the central part of the plate by the tool, and to communicate ultrasonic vibrations, which lead to the relaxation of residual stresses and stabilization of the geometric parameters of the plate. Analytical expressions are obtained in order to calculate technological parameters of the ultrasound processing. Computer simulation was held on the basis of the theoretical and analytical models, which has allowed to identify and to visualize the dependence of residual stress and plate deformation on the duration and amplitude of ultrasonic vibrations. On the basis of the obtained dependences it was found that the vibrational amplitude should be reduced to reduce the residual strain, however this increases the processing time. Thus, the greater the amplitude of the ultrasonic vibrations is, the more intense the reduction of residual stresses is. Intensive changes of the residual strain and stresses in the first few seconds are characterized by high efficiency of ultrasonic stabilization, which is recommended as a replacement for the aging method.
The Dependence of Gibbs Energy of Formation of Niobium Mononitride on its Composition and Temperature in the Range of 1773-2023 K
Authors: Zhikharev V.M. , Pavlovskaya M.S.
Published: October 2018

The article demonstrates the applicability of the interaction parameter method for describing the thermodynamic properties of non-stoichiometric niobium nitrides at temperatures of 1773 ± 2023 K. The authors obtained the equation of dependence of the nitride dissociation elasticity on its composition and temperature. They derived the expression for calculating Gibbs energy of formation of nitrides with a set composition, including stoichiometric, in the range of 1773 - 2023 K.
Resource-Saving System of Heat and Cold Supply in Power Complex of the Metallurgical Plant
Authors: Volkov A.V. , Malenkov A.S. , Shelginsky A.Ia.
Published: October 2018

This paper deals with the problem of energy efficiency improvement of the power supply system at the metallurgical plant. It is known, that up to 50-60% of metallurgical costs of production are energy costs, and there is a significant amount of thermal secondary energy resources, which can be used for heat supply in winter and cold supply in summer. For the organization of the system of waste heat utilization, it is proposed to use an absorption heat transformer, which operates in accordance with the scheme of absorption heat exchanger in winter, and in accordance with the scheme of absorption refrigerating machine in summer.
The Effect of Soft Interlayers on the Behavior of a Four-Layer Titanium-Steel Composite at High Temperatures
Authors: Gurevich Leonid Moiseevich , Pronichev Dmitriy V. , Novikov Roman Evgenyevich
Published: October 2018

The work presents the result of the finite element simulation of the titanium-steel composite with copper-niobium sublayer – VT6-VN2-M1-12Cr18Ni10Ti behavior under axial tension of a cylindrical sample by varying the relative thickness of the soft layer using a SIMULIA/Abaqus software package.
The Influence of Milling Regimes in Beater Mill on Particle Size Distribution and Structural Characteristics of Strontium Hexaferrite Powder
Authors: Yegorov I.N. , Egorov Nikolay Ya.
Published: October 2018

The paper experimentally substantiates effectiveness of method of milling particulate ferromagnetic materials in magneto fluidized bed. Comparative results of particle size distributions and structural parameters of strontium hexaferrite SrFe12O19 powder obtained by milling coarse material in beater mill without electromagnetic effect and in same mill with formation of magneto fluidized bed from mill material are presented. The magneto fluidized bed is formed by constant and alternating gradient magnetic fields with induction lines that are mutually perpendicular and parallel to the plane of rotating beaters. It is shown that application of electromagnetic effect to milling coarse material in beater mill allowed to greatly intensify that process, significantly increase powder quality: increase particle size distribution uniformity and decrease average particle size from 1558.50 μm to 0.56 μm after 120 minutes of processing in the mill. X-ray diffraction analysis showed that milling in beater mill in magneto fluidized bed leads to reduction of coherent-scattering region size, increase of lattice microstrain and dislocation density, making powder more active during sintering process.
Dependence of the Elastic Properties of a Single-Walled Carbon Nanotube on its Chirality
Authors: Sergeeva E.S.
Published: October 2018

Currently, composite materials composed of a matrix and reinforcing components are widely used as a structural material for various engineering devices designed to operate under extreme loads of different types. By modifying a composite with structure-sensitive inclusions, such as a single-wall carbon nanotube, the mechanical properties, especially elastic characteristics, of the resulting material can be significantly improved. The results of investigation of a single-walled carbon nanotubes chirality influence on its elastic properties are presented. Various configurations of nanotubes, such as zigzag and armchair are considered. The dependences of the nanotube bulk modulus and shear modulus of its diameter are shown.
A Study of the Structure and Regularities of Formation of the Compounds during Explosive Welding of Steel-Aluminum Composite
Authors: Kuz'min Vladimir I. , Lysak V.I. , Kuz’min Evgeniy V.
Published: October 2018

This paper discusses the structure and regularities of formation of compounds during explosive welding plate steel-aluminum composite. The influence of thickness of the welded element on the structure and the shear deformation of the metal in the heat-affected zone under different conditions of explosive loading was investigated.
Crystallographic Peculiarities of Shear α-γ Transformation in Austenitic Stainless Steel in the High Temperature Area
Authors: Pastukhov Vladimir I. , Kozlov A.V. , Lobanov Mikhail L.
Published: October 2018

Structure-texture states in 18Cr-9Ni austenitic stainless steel after long-term operation of the tube at high temperatures and neutron irradiation have been investigated with orientation microscopy (EBSD). In the examined samples, cut out at the external surface, a significant concentration of α-phase with the lattice close to bcc has been detected. Phase transformation shows prominent crystallographic direction, caused by initial orientation of austenite grains and tensile stress effect, normally directed at a tangent to its external surface. High-angle boundary spectrum with the most prominent coincidence site lattice (CSL) boundaries, Σ3, Σ11, Σ25b, Σ33с Σ41с, is typical for α-phase. Thus, it can be claimed that austenite transformation was carried out by shear (bainite, taking into account high temperature) mechanism, according to orientation relationships (OR), intermediate between Kurdjumov-Sachs (K-S) and Nishiyama-Wassermann (N-W). Shear γ-α transformation began in austenite on twin boundaries (CSL Σ3), and was carried out in the range determined by initial orientation of γ-phase crystals and effective stress value. Based on high density of CSL boundaries Σ3 in α-phase it has been suggested that its nuclei are represented not by single crystallites, but crystallite couples in twin misorientation.
Influence of Different Factors on Withdrawal Speed of Continuous Cast Billet
Authors: Stolyarov A.M. , Potapova Marina V. , Potapov Michail G.
Published: October 2018

The influence of the St.3sp, 40 and 85 steel grades chemical composition, temperature of the metal in the tundish ladle, billet cross-sectional dimensions (150 × 150 and 152 × 170 mm), the sulfur content in the metal on the speed of withdrawal of the billets from the CCM mold has been investigated. It was established, that the change of the metal temperature in the tundish ladle of the CCM has the greatest effect on the billet withdrawal speed, the change of carbon content in the steel and the billet cross-sectional dimensions influence in less extend, and the sulfur content in the cast steel does not affect at all.
Microstructure and Mechanical Properties of High Strength Alloyed Steel for Aerospace Application
Authors: Maisuradze Mikhail V. , Ryzhkov Maxim A.
Published: October 2018

The high strength aerospace steel alloyed with Cr, Mn, Si, Ni, W and Mo was studied. The austenite transformations under continuous cooling conditions were investigated using the dilatometer analysis at the cooling rates 0.1...30 °C/s. The mechanical properties of the studied steel were determined after the conventional quenching and tempering heat treatment. The dependences of the mechanical properties on the tempering temperature were obtained. The novel quenching and partitioning heat treatment was applied to the steel under consideration. The microstructure and the mechanical properties were studied after three different modes of the quenching and partitioning (QP) treatment: single-stage QP, two-stage QP and single-stage QP with subsequent tempering (QPT).
Synthesis of Aluminum-Matrix Alloys with Al-Zr-W by Metallothermy of Oxides
Authors: Gostishchev V.V. , Kim E.D. , Ri Ernst H.
Published: October 2018

The article presents the results of obtaining complex-alloyed aluminum-zirconium alloys by aluminothermy of initial metal oxides. Aluminum-matrix Al-Zr-W alloys have been obtained by a metal-thermal reduction with an excessive amount of aluminum in the initial charge of zirconium and tungsten oxides. The process of synthesis is presented as partial reduction reactions of zirconium, tungsten and synthesis of intermetallic compounds. It is shown that thermodynamic parameters of the reactions are favorable for the process of formation of refractory metal alloys. It is found that the temperature reached during the melting process makes it possible to obtain intermetallids and to synthesize alloys at the out-of-furnace process in the form of a compact ingot. The composition of the alloys obtained has been determined by an X-ray phase and an element analysis. It is established that the alloys have a composite structure: intermetallides Al3Zr and Al4W are distributed in the aluminum matrix.
To the Question of Evaluation of the Anode Voltage Drop
Authors: Osipov A.M. , Bezgans Yu.V.
Published: October 2018

The paper presents the results of the evaluation of the drop of anode voltage while the open burning arc between the steel plate (cathode) and the wire electrode CuSi3Mn1. Experiments were performed to determine the temperature of metal of electrode droplets at manual and mechanized deposit welding. The results of experimental determination of heat contents and temperature of metal of electrode droplets are represented on the chart.
A Study of the Influence of the Manufacturing Process Parameters on the Distribution of Residual Stresses in Pipe Walls during Sink Drawing
Authors: Shimov Georgy V. , Shimov V.V. , Zavalin Artem
Published: October 2018

The paper presents the results of the study of residual stresses in stainless cold-drawn pipes obtained during FEM simulation of the process of sink drawing. The relation of the value of reduction, the taper angle of the working area of the drawing zone, the drawing speed and the friction coefficient to the pattern of distribution and the value of residual stresses in the pipe walls was established.
Computerized Study of Intense Deformed State of Grinding Plate of High-Manganese Steel
Authors: Erdakov Ivan Nikolaevich
Published: October 2018

The article studies peculiarities of shrinkage formation during induration of a grinding plate made of high-manganese steel. It suggests a method evaluating influence of the defect of such kind on intense deformed state of a grinding plate occurring in the result of impact loads of preparation grinding plates. The finite-element method in the DEFORM software package is used for calculating lumped voltages for different parameters of circular section macropores.
Increase in the Slag Resistance of Refractories Based on the Al2O3-SiC-SiO2 System
Authors: Lonzinger Tatiana M. , Skotnikov Vadim A.
Published: October 2018

The technology for manufacturing corundum-carbide-silicon refractories with increased slag resistance has been developed. It is shown that one of the directions for improving the quality of carbon-containing products is the creation of protective antioxidant coating on the surface of particles. A dense protective film is formed during the processing on the surface of carbon-containing particles. The coating does not break down when heated to the melting temperature of steel. Therefore, the number of heat-conducting particles in the bond can be increased without the risk of loss of strength. An increase of the number of high-heat-conducting particles reduces the value of the temperature gradient inside the refractory and reduces the zone impregnated with the melt. A technique has been developed that makes it possible to determine the degree of interaction of a refractory with metal (slag) in ground samples under the binocular microscope MBS-9. The proof of high slag resistance is the depth of penetration of metal and slag into the structure of the sample by not more than 1 to 2 mm without changing the lateral surface of the conical hole.
Examination of Hardening Curves Definition Methods in Torsion Test
Authors: Erpalov Mikhail , Kungurov E.A.
Published: October 2018

Torsion tests allow studying the rheological properties of materials over a wide range of strain and strain rate values, as well as temperature. A key moment in construction of hardening curves is the interpretation of experimental data, which are usually the torque – angle of twist curves. However, there is a number of independent methods to obtain interpretation of experimental data. In addition, there is no single approach to determining the degree of equivalent strain in torsion test. The aim of this paper is to review existing hardening curves definition methods in torsion test and to examine them with the use of finite element modelling.
Influence of Nitrogen and Nitride-Forming Elements on Properties of Boron-Treated Steel
Authors: Maznichevsky Alexander N. , Goikhenberg Yuri N. , Sprikut Radii V.
Published: October 2018

Microalloying has received increased attention in recent years. The aims of the study were to identify and to examine the influence of nitrogen concentration in steel and small additions of nitride-forming elements on the hardenability of a boron-treated manganese-vanadium steel 40GF-VI. The study has shown that the increase in nitrogen concentration from 0.004% to 0.015% increases the hardenability of steel. It was found that a small amount of titanium (about 0.02%) in steel with low concentration of nitrogen (0.004%) is sufficient to bind it to nitrides, which makes it possible to save the most of boron in an active state (in a solid solution). A residual amount of titanium and aluminum in the range of 0.015-0.020% of each in steel with nitrogen concentration in the range of 0.010-0.015%, which is typical of an electric arc melting steel, is insufficient to bind all nitrogen. As a result, a part of nitrogen is spent on the formation of boron nitrides, which reduces the effect of boron on the hardenability of manganese-vanadium steel microalloyed with boron. Some methods of protecting boron in steel are briefly described. The study has established that grain refinement is observed with increasing nitrogen content in steel. Introduction of boron, in absence of titanium, does not change the size of the austenite grain in the entire range of the investigated temperatures. The optimum combination of strength, plastic and ductility characteristics in steel microalloyed with boron and additives of aluminum and titanium was obtained.