bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of family involvement in business on capital structure decisions: a literature review
Authors: Ahmed Moussa Amr , Elgiziry Khairy
Published: March 2019

Family-controlled firms are a unique form of business because of the special nature of its ownership structure, management style, and financing needs. Moreover, these firms face difficulty in achieving a balanced mix of available financing alternatives (i.e., debt and equity), and this mix has a direct impact on the firms’ profitability, risk, and value. Therefore, the purpose of this study is to review the literature on how family involvement in business via ownership, management, and control affects capital structure decisions. The review showed that in a comparison with nonfamily businesses, family-controlled firms on average have higher debt levels. Additionally, family ownership is positively associated with debt financing, and the participation of family members in a firm’s top management leads to an increase in the firm’s overall debt level. Insights generated from the current study highlight the critical influence of family involvement in business on key financial policies such as capital structure decisions.
Optimization of Expression of Nitrilase from Alcaligenes denitrificans in Rhodococcus rhodochrous to Increase the Efficiency of Biocatalytic Synthesis of Ammonium Acrylate
Authors: Grechishnikova E.G. , Shemyakina A.O. , Novikov A.D , Kalinina T.I. , Epremyan A.S. , Glinskii S.A. , Minasyan R.A. , Voronin S.P. , Yanenko A.S.
Published: March 2019

The Rhodococcus rhodochrous M33-2nit strain containing in its chromosome two copies of a gene for A. denitrificans В-9582 NitC1 nitrilase under the control of a promoter region of genes of R. rhodochrous M8 nitrile hydratase has been constructed. The culturing of the strain was optimized and it was shown that using a two-substrate cultivation scheme on glucose and acetate, it was possible to obtain up to 17 g cdw/L of cells with the specific activity of 7 units/mg cdw. A capacity of synthesizing ammonium acrylate from acrylonitrile by the cells of A. denitrificans В-9582 and A. rhodochrous M33-2nit under the conditions simulating the industrial process was compared. It was shown that the cells of R. rhodochrous M33-2nit were able to produce ammonium acrylate at higher rates of acrylonitrile feeding, than the cells of A. denitrificans В-9582. Using the R. rhodochrous M33-2nit cells, high-concentration solutions of ammonium acrylate (450 g/L) were obtained with the conversion rate of 99.5%. Rhodococcus rhodochrous, nitrilase, nitrile hydratase promoter, ammonium acrylate, acrylonitrile, biocatalysis.
Synthesis and Physicochemical Properties of Exopolysaccharides Produced by Lactic Acid Bacteria Leuconostoc mesenteroides Cultured in Lactose- and Sucrose-Containing Medium
Authors: Semenova M.G. , Khokhlacheva A.A. , Antipova A.S. , Murzina E.D.
Published: March 2019

The dynamics of Leuconostoc mesenteroides bacteria growth and synthesis of exoplysaccharides when cultured on a medium containing whey and sucrose has been investigated. It was shown that exopolysaccharides were produced during the culture growth and the addition of sucrose increased in the productivity of those compounds without affecting their composition. Using the dynamic and static methods of light scattering, it was shown that sucrose as a medium component modified physicochemical properties of exopolysaccharides changing their structural and thermodynamic characteristics in aqueous medium, which affected their functional activity and determined the way of their most efficient use. kefir fungi, lactic acid bacteria, physicochemical properties of exopolysaccharides.
Audyty kliniczne IAEA - droga do bezpiecznej i skutecznej realizacji radioterapii
Authors: Konstanty Ewelina
Published: March 2019

Celem niniejszego artykułu jest przedstawienie niektórych działań Międzynarodowej Agencji Energii Atomowej oraz Światowej Organizacji Zdrowia związanych z audytami klinicznymi, które przyczyniają się do bezpiecznej i skutecznej realizacji radioterapii.Od ponad 30 lat Międzynarodowa Agencja Energii Atomowej (ang. International Atomic Energy Agency, IAEA) prowadzi wiele projektów mających na celu podniesienie jakości, bezpieczeństwa, a także dostępu do radioterapii na całym świecie. IAEA wspiera rozwój i normalizację w zakresie dozymetrii promieniowania oraz dostarczania usług dozymetrycznych państwom o niskich i średnich dochodach, co przyczynia się do ujednolicenia procedur dozymetrycznych na całym świecie. IAEA oferuje wspólną i jednolitą metodologię audytów dozymetrycznych opartych na detektorach termoluminescencyjnych, przekazuje wytyczne i zapewnia zaplecze techniczne dla krajowych sieci audytujących ośrodki radioterapii.
Użyteczność metod radioizotopowych w leczeniu przerzutów nowotworowych do układu kostnego – przegląd metod
Authors: Zając Roksana , Radzińska Paulina , Pietrzak Agata Karolina , Wiecheć Katarzyna , Żurawski Jakub , Cholewiński Witold
Published: March 2019

StreszczenieLeczenie dolegliwości bólowych będących konsekwencją przerzutów nowotworowych w układzie kostnym stanowi ważny problem kliniczny z uwagi na istotne obniżenie jakości życia chorego onkologicznego. Towarzyszące zaawansowanej chorobie nowotworowej zmiany przerzutowe oprócz bólu, są także przyczyną złamań patologicznych oraz upośledzenia funkcji ruchowych pacjenta, a nieleczone mogą być przyczyną krytycznych dla życia chorego powikłań. Zastosowanie leczenia radioizotopowego jako jednej z form terapii paliatywnej, jest ważnym i efektywnym sposobem zapobiegania komplikacjom zdrowotnym związanym z rozwojem przerzutów do układu szkieletowego.Abstract  Palliative therapy in patients’ suffering from metastatic bone lesions is an important clinical problem due to a significant reduction in the quality of life of an oncological patient. The metastatic bone lesions regardless pain are also the cause of pathological fractures and impairments of the patient's motor functions and untreated can affect mortality more often than primary neoplastic disease. The palliative therapy using radioisotopes seems to be an important and effective method which might prevent the critical health complications caused by the skeletal tumors.
Genetyczne podłoże nowotworów tarczycy – wybrane zagadnienia
Authors: Wróblewska Joanna , Marszałek Andrzej
Published: March 2019

Nowotwory tarczycy są najczęściej występującymi wśród nowotworów układu wewnątrzwydzielniczego. W ciągu ostatnich dekad liczba nowych zachorowań znacząco wzrosła i wciąż wykazuje tendencję wzrostową. U podstaw choroby nowotworowej leżą zmiany zachodzące w komórkach na poziomie molekularnym, głównie mutacje somatyczne w określonych onkogenach lub genach supresorowych. Analiza profilu molekularnego w zakresie mutacji somatycznych występujących w genach związanych z nowotworami tarczycy pozwala na poszerzenie wiedzy na temat molekularnych podstaw nowotworzenia i poznanie roli ich genetycznego podłoża w rozwoju choroby, jej progresji i rokowaniu powodzenia terapii. Mutacje w genach z rodziny RAS (NRAS, KRAS, HRAS) związane są najczęściej z typem pęcherzykowym nowotworu tarczycy, ale wykrywane są także w przypadku typu anaplastycznego. Mutacje w genie BRAF związane są natomiast z typem brodawkowym, ale również mogą występować w typie anaplastycznym. Mutacje w genie TP53 lub regionie promotorowym genu TERT związane są z większą agresywnością nowotworu, przerzutami i gorszym rokowaniem dla chorego.
Ocena najnowszych trendów w diagnozowaniu i leczeniu nowotworów złośliwych górnego odcinka układu pokarmowego na rok 2014 wg doniesień prezentowanych podczas konferencji ASTRO 56 w San Francisco
Authors: Martenka Piotr
Published: March 2019

Leczenie nowotworów złośliwych górnego odcinka układu pokarmowego, zarówno w USA, jak i w Europie, oparte jest o postępowanie wielodyscyplinarne. Podstawą terapii jest leczenie chirurgiczne, podczas gdy radioterapia i chemioterapia stosowane są głównie jako terapie uzupełniające. Wyniki dotychczasowych badań na temat skuteczności leczenia uzupełniającego są bądź sprzeczne, jak w przypadku stosowania radio-chemioterapii w leczeniu raka trzustki, bądź znane są alternatywne schematy postępowania o podobnej skuteczności, których jednak nie porównano bezpośrednio, jak w przypadku leczenia uzupełniającego raka żołądka. O wyborze danego schematu leczenia uzupełniającego decydują lokalne preferencje. Ponieważ radioterapia w leczeniu uzupełniającym nowotworów złośliwych górnego odcinka układu pokarmowego ma więcej pozytywnych wyników badań klinicznych w USA – tam też częściej stosowana jest radio-chemioterapia pooperacyjna w resekcyjnym raku żołądka czy trzustki, podczas gdy w Europie znacznie powszechniej stosowane są, odpowiednio okołooperacyjna chemioterapia w raku żołądka, czy pooperacyjna chemioterapia w raku trzustki, zgodnie z wynikami badań europejskich wykazujących większą skuteczność takiego postępowania.
The Use of Naltrexone in Dermatology. Current Evidence and Future Directions
Authors: Sikora Mariusz , Rakowska Adriana , Olszewska Małgorzata , Rudnicka Lidia
Published: March 2019

Naltrexone is a competitive opioid receptor antagonist approved as supportive treatment in alcohol dependence and opioid addiction. At a dose of 50-100 mg daily, naltrexone is used off-label in dermatology for the treatment of trichotillomania and different types of pruritus. At a dose as low as 1- 5 mg per day, naltrexone demonstrates immunomodulatory action i.e. modulates Toll-like receptors signaling, decreases release of proinflammatory cytokines (tumor necrosis factor, interleukin-6, interleukin- 12), inhibits T lymphocyte proliferation, down-regulates the expression of chemokine receptors and adhesion molecules. The efficacy of standard and low doses of naltrexone in a variety of dermatological disorders has been reported. These include diseases such as familial benign chronic pemphigus (Hailey-Hailey disease), dermatomyositis, systemic sclerosis, psoriasis and lichen planopilaris. Optimistic preliminary findings, low cost of therapy and good tolerance make naltrexone a promising alternative therapy or adjunct drug in dermatology.
The Effect of Lunate Morphology in Carpal Disorders: Review of the Literature
Authors: Rhee Peter C. , Moran Steven L.
Published: March 2019

Variation in lunate morphology can exist based on the absence (Type I) or presence
(Type II) of medial facet on the distal articular surface of the lunate that contacts the proximal pole
of the hamate. This additional lunatohamate articulation can affect load transmission across the radiocarpal
joint and exert an influence on carpal kinematics. A Type II lunate is protective against
carpal instability patterns associated with scaphoid nonunions and scapholunate dissociations. It
may also play a role in the progression of carpal collapse that occurs in Kienböck disease. This review
summarizes the effect of lunate morphology in the outcomes of non-operative and operative
treatment of carpal disorders.
Adequacy of the ASTM C1240 Specifications for Nanosilica Pozzolans
Authors: Hassan Maan S.
Published: March 2019

Background:

Nano-silica is a new pozzolan that is boosting the field of nanomaterials and can be used effectively in the concrete industry. ASTM C1240 is used to qualify silica fume pozzolans for use in concrete and for marketing purposes.

Objective:

The present study aims to assess the adequacy of ASTM C1240 in qualifying nanosilica for use in concrete and to introduce a modified procedure to measure the pozzolanic activity of nanosilica used with cementitious composites.

Methods:

The effects of various particle sizes and dosages on the compressive strength of blends in standard mortar were investigated. The correlation between the chemical reactivity and the compressive strength were also investigated using TGA and XRD analyses. The criterion conceived was validated at two ages: 7 days and 28 days.

Results and Conclusion:

The strength activity index results revealed that the following standard procedure ASTM C1240 is not applicable for nanosilica due to the high surface area and great pozzolanic reactivity of SiO2 nanoparticles, so a lower cement replacement percentage should be used. This study suggests that it be no more than 7%. The pozzolanicity testing results confirm that a nanosilica replacement level of more than 7% could not be effective in transforming further Portlandite into a C-S-H or other major cementing compound, leading to a “false negative” for nanosilica pozzolans.
Preparation and Characterization of Rutile Titania Nanofluids Stabilized in Different Surfactants Base Fluids
Authors: El-Salamony Radwa A. , Abd-Elaziz Mohamed Z. , Morsi Rania E. , Al-Sabagh Ahmed M. , Hassan Saad S.M.
Published: March 2019

Background:

Improvement of conventional heat transfer fluids for achieving higher
energy efficiencies in thermal equipment is a key parameter to conserve energy in industries. The
heat transfer fluids such as water, oil and ethylene glycol greatly suffer low heat transfer performance
in industrial processes. There is a need to develop new types of heat transfer fluids that are
more effective in terms of heat transfer performance. Nanofluids enhance thermal conductivity
and improve the thermal performance of heat transfer systems.

Methods:

New titania nanofluid samples consisting of 0.0625 to 1% TiO2 nanoparticles were
prepared and characterized. The method of preparation was based on prior precipitation of TiO2
from an ammoniacal solution of pH 9 and calcination at 900°C. Solubilization, homogenization
and stabilization of the of the nanoparticles were performed by sonication in the presence of sodium
dodecyl sulfate (SDS) anionic surfactant and cetyltrimethylammonium bromide (CTAB)
cationic surfactant.

Results:

This treatment was also utilized to increase the stability and improve the thermal properties
of the fluid.

Conclusion:

Several characterization techniques including measurements of hydrodynamic size
distribution, zeta potential, transmission electron microscopy (TEM), viscosity, density, specific
heat, thermal conductivity, and sedimentation photo capturing were used to measure and confirm
the stability and sedimentation rate of the prepared nanofluids.
Robust Two-degree-of-freedom Control Based on H∞ Method for PMSM Drive System
Authors: Zhu Qixin , Xiong Lei , Liu Hongli , Zhu Yonghong , Zhang Guoping
Published: March 2019

Background:

The conventional method using one-degree-of-freedom (1DOF) controller
for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between
the dynamic performance and the robustness.

Methods:

In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF)
controller has been proposed to improve the position control performance of PMSM servo system.
Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed
and discussed in detail.

Results:

The trade-off problem between the dynamic performance and robustness which exists in
one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory.
Then, through H∞ control theory, the design of robust position controller can be translated
to H∞ robust standard design problem. Moreover, the control system with robust controller has
been proved to be stable.

Conclusion:

Further simulation results demonstrate that compared with the conventional PID control,
the designed control system has better robustness and attenuation to the disturbance of load
impact.
Kinematics and Control of a Planar Cable Robot
Authors: Kapitány Pálma , Lénárt József
Published: March 2019

This paper deals with the kinematics and control of a planar cable robot [1], which is driven by four DC motors with gear. Cable robots are frequently used e.g., for the motion of cameras in sport halls and stadiums and also in high storage logistical systems [2]. Main goal of this research work is to design and build a test bench with low budget, which can model the motion of real life cable robots.
Examining the movement differences in the behavior of normal and rack railway vehicle
Authors: Nagy Andor , Lakatos István
Published: March 2019

The rack railway is a special type of railroad. There weren”t much built worldwide, and their number is decreasing. Now, in Budapest, there is a possibility to create an interoperable vehicle, based upon the experience gained from the previously operated line, and all the research regarding its unique characteristics. One from the many important sector of its operation, is the rail/rack/vehicle system. Its mechanical model is far more complex than a traditional railroad vehicle. We will demonstrate its behaviorial differences from a traditional railroad vehicle.
Experimental Study Regarding The Influence Of Compliant Hinges Geometry In Mechanical Structures
Authors: Lates D. , Casvean Marius
Published: March 2019

In this paper an experimental study will be carried out, on the influence of geometry, using different compliant mechanical couplings. In the first part of the paper will be presented the compliance of the couplings and a number of consecrated works on this theme will be quoted. The article continues with the case study made on three types of compliant joints. These joints and the mechanics that substitute them will be presented. Towards the end of the paper we explain the experimental method and its results. The final ideas concerning this work will be filled out by conclusions and research directions.
PVC/LDPE Blends: Relationship Between Thermal/Mechanical Properties, Structure and Blend Behaviour
Authors: Román Krisztina , Zsoldos Gabriella
Published: March 2019

In this paper the effect of LDPE content in PVC foams are examined on the structure of both the foam and the LDPE. We attempt to understand how LDPE content affects the structure of PVC in blends and how it changes the glass-transition (Tg). These parameters often provide important information related to the overall macromolecular structure of the polymer blend. Thermal analytical techniques such as differential scanning calorimetry (DSC) often used to determine the structural transformation of samples. The effect of the miscibility and composition of the PVC/LDPE foam blends on the thermal stability were also investigated.
A study of pressure-sinkage relationship used in a tyre-terrain interaction
Authors: Salman Nihal Dawood , Kiss Péter
Published: March 2019

The vehicle applies a normal load to the terrain, which causes sinkage and motion resistance. To forecast the normal pressure distribution on the interface of a vehicle–terrain and the tractive performance of a vehicle, the response of the terrain to normal load (which is characterized by pressure–sinkage relationship equations) must be measured. This paper presents the common conventional pressure sinkage models used in terramechanic and the modification that happened to this models. In addition the features of the new models.
Neural Network Based Enveloping Model of Agricultural Tyre
Authors: Stojic Boris
Published: March 2019

The vibration properties of agricultural tractor’s tyres significantly influence its response in terms of the exposure of the human operator to mechanical vibrations, which is still one of the key problems in the design and exploitation of tractors. The behaviour of the tyre in this sense is significantly influenced by the mechanism ofgeometric filtering of the short-wavelength unevenness of the unprepared ground mostly encountered by tractor during in-field operations. Herein, this aspect of tyre behaviour was studied with tyre rolling quasistatically over singular obstacle. Based on experimental results, neural network based model of tyre enveloping behaviour was developed. Main model properties are high computational efficiency, simplicity regarding number of input quantities and absence of the need for explicit parametrization etc. Main shortcomings of modelling approach used are high developing effort, labour-intensive experimental preparations and lack of flexibility regarding tyre design and operating parameters
Impact of physical properties of workpiece material on material removal rate at EDM
Authors: Straka Luboslav , Dittrich Gabriel
Published: March 2019

The volume stock removal from the workpiece during the EDM is one of the important parameters that characterize the productivity of the electro-erosion process itself. Therefore, in terms of the economic efficiency of the electro-erosion process, it is appropriate that the value of the MRR parameter is as high as possible. The paper describes the results of experimental research to identify the extent of influence of the physical properties of the workpiece material on the workpiece material removal rate at EDM. The experiments were carried out using an Aggregron Hyperspark 3 electro-erosion machine on selected tool steels. As a tool electrode material for experimental purposes, graphite with the designation EX-60 was chosen because of its practical advantages.
Simulation of an Operating Machine in Dust Chamber
Authors: Tollár Sándor , Bolló Betti
Published: March 2019

Auxiliary equipment used in the automotive industry, such as generator, air conditioner, or starter, is often exposed to harsh conditions, for example splash water, frost, or serious dust load. Therefore, these auxiliary devices are intended to be prepared by the manufacturers to these conditions. The topic of this paper is a part of the analysis of the dust control of generators, which in principle is no different from the examination of other equipment. The flow around the generator and in the dust chamber was simulated by Ansys FLUENT.
Effects of TIG Reheating on Duplex Stainless Steel Weld Microstructure
Authors: Varbai Balázs , Tolnai Ferenc , Májlinger Kornél
Published: March 2019

Duplex stainless steels (DSS) gaining their excellent mechanical properties and corrosion resistance due to their austenitic-ferritic microstructure, ideally in the same amount. However, to keep this ideal phase ratio during arc welding is very difficult. Generally, the arc welding processes will result in more ferritic microstructure in the weld metal and in the heat affected zone, due to the rapid cooling. The ferritic microstructure can cause chromiumnitride precipitation, because the nitrogen solubility in ferrite phase is very low below 700 °C. These chromiumnitride precipitations can cause loss of corrosion resistance and mechanical properties. However, during subsequent reheating, the chromium-nitrides can dissolve and act as a secondary austenite nucleation site in the ferritic microstructure. In our research we welded DSS specimen autogenously, with tungsten inert gas welding using pure argon and 94 % argon + 6 % nitrogen as shielding gasses. In the first case the sub-sequent solid-state reheating caused 20 % increase in the austenite fraction of the weld metal but with the use of mixed shielding gas only 5 % increase.
The observation of natural analogies and their use in design
Authors: Darabos Anita
Published: March 2019

According to, Thomas Heatherwick, who was an English architecture, ‘The biggest object is a building’. [1] Nature has phenomenal problem solving skills – ‘Nature knows it better’. It has an impact on us and on our subconscious.
Micromechanical model of dry friction hybrid polymer composite clutch facings
Authors: Biczó Roland , Kalácska Gábor
Published: March 2019

Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a complex material are described in this paper along with simplification ideas and solutions.
The Effect of Fluxes on the Melt Quality of AlSi7MgCu Alloy
Authors: Gyarmati Gábor , Fegyverneki György , Mende Tamás , Tokár Mónika
Published: March 2019

The presence of inclusions such as oxides, carbides or refractory particles can be harmful to the mechanical and surface characteristics of castings. Inclusion-rich metals result in lower fluidity and feeding capability during casting. Nowadays, solid fluxes are widely used in foundries in order to reduce the inclusion content of aluminium melts. In this study, the effect of four different fluxes on the melt quality was studied. First, the inclusion content of the flux-treated melt, and then the properties of the fluxes (i.e. chemical composition and melting temperature) were examined.
Designing of lab-scale anaerobic digester equipped with maxblend impeller to evaluate effect of mixing on anaerobic digestion
Authors: Buta Singh , Szamosi Zoltán , Siménfalvi Zoltán
Published: March 2019

Operational parameters can be easily controlled at lab scale experiments for an anaerobic digestion process. Our aim is to design a lab-scale digester equipped with an impeller to investigate how the geometry of impeller and different mixing modes effect the biogas yield of digester. Further, the methods of measuring the gas volume, gas composition, mixing intensity, torque, temperature are discussed in this article. The assembling of 4 liters digester is described which can be operated at various operating parameters which control the anaerobic digestion process. Mixing is very important to enhance efficiency of an anaerobic digester. To attain mixing Maxblend impeller is used in this lab-scale digester due to its better performance for mixing and power consumption. Various design consideration has been described.
Increasing the life of mulching tools
Authors: Ľuptáčiková Veronika , Hnilica Richard , Ťavodová Miroslava
Published: March 2019

Areas after mining or calamity are not amenable to immediate afforestation and require some adjustment. After removal of wood biomass, the rest of the residue is scattered throughout the area. To modify them, Several methods can be used to remove it. The optimal conditions for the planting environment and the subsequent adaptation process of the planting can be achieved by its mechanical, biological, chemical treatment. The basic prerequisite for a successful renewal of forests is their release from undesirable increases, in some cases from foams (trees) from mining waste. The area is also released when forest nurseries, seed plantations, etc. are established. The main purpose of the release of surfaces is to achieve the maximum throughput of the area for the machines to be moved. They wear during work. Wearing is a permanently undesirable change in the surface due to the interaction of functional surfaces or functional surface and wear medium. A tool that does not have any editing can go into a state where it can no longer be used anymore. An experiment was carried out in which 9 new teeth were placed on the rotor of the crusher and their wear patterns were observed. The article shows the progress of tool wear over time.
Investigation of Aluminum Dross as a Potential Asphalt Filler
Authors: Udvardi Bella , Géber Róbert , Kocserha István
Published: March 2019

There is a great concern about utilizing different waste materials all over the world. Stockpiling in landfills is not a final solution, therefore researchers try to find alternative methods to utilize these materials [1-5]. One potential area may be road construction. Fillers are one of the most important components of asphalt pavements. It has a dual role. First of all, these fine grained mineral materials (d<0.063 mm) enhance the cohesion with bitumen. Second is to fill the gaps between the particles to produce more compact mixture [6]. The aim of this research is to reveal the possibility of utilization of aluminum dross as a potential asphalt filler. This material, which is a by-product of aluminum casting process, is produced in large quantities year by year and its storage in landfills is not a proper solution. Therefore, there is an increasing demand to utilize this material. During the research material structural tests were made, which can characterize the samples (limestone powder, dross), and the cohesion between bitumen and filler can also reveal. Particle size distribution, BET specific surface area and porosity were investigated. Scanning electron micrographs were taken and oil adsorption test were also made.
The Effect of MMS Lubrication on Surface Roughness During Machining
Authors: Kári-Horváth Attila , Pataki Tamás , Szakál Zoltán
Published: March 2019

I display this paper the chipping front metal of cutting allocated geometric, considering particular the friction. I catch the attention energy's balance sheet someday metal of cutting, open one new direction the manufacture technology. I display this new direction's metal of cutting condition. but built I delineate his paper final division this new policy searching programme, consumed trial instruments as well as the evaluation's mode.
Numerical Model Analysis of Natural Gas Combustion Burners
Authors: Ibraheem Amjd , Szodrai Ferenc
Published: March 2019

Traditional power plants still the dominating power source for all the major industries and powerdemanding facilities, the most crucial facility for the whole plant operations is the industrial boiler which generatessteam, heating energy or electrical power. Boilers generate energy by combustion. The improvement of combustion efficiency could greatly influence the energy consumption and will make the boiler more efficient and cleaner (less emissions), that’s why it is important to understand the combustion and thermal flow behaviours inside the boiler. Beside experimental testing, computational work nowadays becoming more and more important due to lower cost and acceptable accuracy with minimum error. With numerical calculations method, the computational model created by a Computational Fluid Dynamics (CFD) software could reduce a lot of trial and error on experimental work. In this paper utilizing the ANSYS FLUENT 19.1 software to make crate the combustion model. The ratio of air to fuel mixture, the equivalency factor, mass flow rate of the mixture, velocity, mass fractions of the mixture components (fuel and air) and their temperatures will serve as the input parameter while the exhaust gase component mass fraction, temperature, mass flow and velocity will be monitored.
Время жизни неравновесных носителей заряда в полупроводниках с близкими значениями запрещенной зоны и спин-орбитального отщепления
Authors: Баженов Н.Л. , Мынбаев К.Д. , Семакова А.А. , Зегря Г.Г.
Published: March 2019

AbstractExpressions for the Auger- and radiative-recombination rates are derived in terms of Kane’s model for materials with a band-gap width close to the spin-orbit splitting energy, which is the case for InAs, InAsSb solid solutions, etc. Our results are compared with simplified expressions for recombination rates, frequently used in publications. It is shown that the nonparabolicity of the electronic structure should be taken into account in calculations of the recombination rates. As an example, the temperature dependences of the charge-carrier lifetimes governed by radiative and non-radiative processes are calculated for InAsSb solid solutions.
Quantum Confined Stark effect and temperature dependencies of photoluminescence of InAs quantum dots coupled with AlGaAs/GaAs two dimensional electron gas -=SUP=-*-=/SUP=-
Authors: Khmissi H. , El Sayed A.M.
Published: March 2019

AbstractIn this work, Experimental study of the influence of internal electric field and the temperature on the photoluminescence of InAs self assembled quantum dots inserted in AlGaAs/GaAs modulation doped hetero-structure have been investigated. The internal electric field is controlled by an appropriate design of the hetero-structure. We have observed a red shift of the photoluminescence position peaks result from the quantum confined Stark effect due to the local electric field existing in the structure. Estimation values of the internal electric field have been obtained through carrier’s densities values in interface of AlGaAs/GaAs hetero-junction. An anomalous dependence of the full width at half maximum with temperature has been found, which attributed to the carrier’s dynamics between InAs quantum dots layer and the two-dimensional electron gas.
Влияние облучения электронами с энергией 0.9 МэВ на вольт-амперные характеристики и низкочастотные шумы 4H-SiC pin-диодов
Authors: Добров В.А. , Козловский В.В. , Мещеряков А.В. , Усыченко В.Г. , Чернова А.С. , Шабунина Е.И. , Шмидт Н.М.
Published: March 2019

AbstractIt is established experimentally that noticeable changes in the I – V characteristics and low-frequency noise in 4 H -SiC pin diodes irradiated by electrons with an energy of 0.9 MeV are observed after doses of Φ ≥ 1.4 × 10^15 cm^–2. The currents in the forward and reverse branches of the I – V characteristics vary nonmonotonically at voltages lower than 2 V with increasing dose, which is explained by the interaction between the excited electronic subsystem and metastable defects. In this case, a steady increase in the ideality factor and the series resistance of diodes in the region of exponential growth of the I – V characteristics at voltages exceeding 2 V is observed. The reliable operation of microwave devices with low-noise 4 H -SiC pin diodes under conditions of electron irradiation is possible up to a cumulative dose of Φ ≤ 10^15 cm^–2. In microwave devices, the level of low-frequency noise in which is irrelevant but the stabile regime of parameters is of importance, the dose can be increased to Φ ≈ 8 × 10^15 cm^–2.
Фото- и термофорез нагретых умеренно крупных аэрозольных частиц сферической формы
Authors: Малай Н.В. , Щукин Е.Р.
Published: March 2019

AbstractA theory of photo- and thermophoresis of a heated medium-size spherical aerosol particle is proposed in the quasi-stationary Stokes approximation at relatively small Reynolds and Peclet numbers. Gas-dynamic equations are solved with allowance for power dependences of the molecular transport (viscosity and thermal conductivity) coefficients and density of the gas medium on temperature. Boundary conditions take into account effects that are linear with respect to the Knudsen number. Expressions for the total force and velocity are derived. It is shown than the above effects may substantially affect the motion of a heated particle.
Конструкционные прочностные параметры и разрушение ультрамелкозернистого титана Grade 4, полученного методом равноканального углового прессования РКУП-К
Authors: Смирнов И.В.
Published: March 2019

AbstractProcessing of metals and alloys by severe plastic deformation (SPD) is accompanied by refinement of the material grain structure, which can increase their physicomechanical properties, for instance, unique tensile strength. However, studies of mechanical properties of materials after SPD are usually limited by tensile tests and other properties of strength and fracture are not sufficiently considered. This article presents experimental studies of ultimate tensile strength, impact toughness, fracture toughness, as well as respective surfaces of fracture of initial and ultrafine-grained pure Grade 4 titanium fabricated by continuous equal channel angular pressing. The results demonstrated that upon high ultimate tensile strength after SPD the material demonstrates decreased resistance against initiation and propagation of cracks upon single loading. The fracture surface of both states of titanium structure reveals mainly localized plastic deformation.
Фононная теплопроводность и фазовые равновесия в наночастицах системы Bi-Sb фрактальной формы
Authors: Шишулин А.В. , Федосеев В.Б. , Шишулина А.В.
Published: March 2019

AbstractThe thermal conductivity component associated with lattice vibrations is one of the quantities determining the thermoelectric activity of a material. We have simulated the dependences of phase composition and the phonon component of the thermal conductivity associated with it on the shape of nanoparticles of a Bi–Sb alloy with an equiatomic composition and with core–shell configuration. The shape of a particle is simulated by a coefficient corresponding to the extent of deviation of the particle shape from spherical or by its fractal dimension. It is shown that mutual solubilities of components depend on the nanoparticle shape and on the mutual arrangement of coexisting phases, and the thermodynamic equilibrium position for particles with complex morphology corresponds to the homogeneous state. Homogenization of a nanoparticle reduces the phonon component of its thermal conductivity by 70–80%.
Ионно-оптическая система источника ионов с фокусировкой по энергии в формируемом пучке
Authors: Аверин И.А. , Бердников А.С. , Масюкевич С.В. , Самсонова Н.С. , Галль Н.Р. , Галль Л.Н.
Published: March 2019

AbstractWays to reduce ion beam intensity losses in a mass spectrometric ion source, which are caused by chromatic aberration of its immersion ion-optical system, are considered. These losses are rather significant in forming a beam from ions with a large energy spread. The reduction of aberration losses is especially important when ion sources are used jointly with mass analyzers with energy focusing. It is shown that these losses can be reduced significantly by using a new type of ion-optical system of the ion source, which includes achromatic elements. A special method for calculating such elements is given. Computer simulations have shown high efficiency of such elements in the ion-optical path of ion sources of mass spectrometers.
Изотопные эффекты в спектрах комплексов с водородной связью. Экспериментальное и теоретическое изучение спектра ИК поглощения комплекса (-=SUP=-12-=/SUP=-CH-=SUB=-3-=/SUB=-)-=SUB=-2-=/SUB=--=SUP=-13-=/SUP=-CO...НF
Authors: Булычев В.П. , Енгалычева Е.А. , Тохадзе К.Г.
Published: March 2019

AbstractIR absorption spectra of mixtures (^12CH_3) $$_{2}^{{13}}$$ CO/HF and free (^12CH_3) $$_{2}^{{13}}$$ CO molecules are recorded in the region of 4000−800 cm^−1 with a Bruker IFS-125 HR vacuum Fourier spectrometer at room temperature with a resolution of 0.05 cm^−1. Absorption bands of the (^12CH_3) $$_{2}^{{13}}$$ CO…HF complex are obtained by subtracting the absorption bands of free HF and acetone molecules and absorption lines of atmospheric water from the experimental spectrum of mixtures. Spectral characteristics of the 2ν(^13C=O) overtone band of free acetone were also recorded. Comparison of the spectral data obtained with the analogous data measured earlier for the (^12CH_3) $$_{2}^{{12}}$$ CO…HF complex shows changes in the absorption spectra of complexes caused by ^12C → ^13C isotopic substitution. The frequencies and intensities for absorption bands of both complexes are calculated using the perturbation theory and methods MP2/6-311++G(2d,2p) and MP2/6-311++G(3df,3pd) with allowance for the error of superposition of basis functions of the monomers. The calculated results are in good agreement with the experimental data and are used to interpret the observed spectra. The influence of anharmonic effects on the frequencies and intensities of the strongest ν(H–F) and ν(^13C=O) bands is examined with the help of variational calculations. It is shown that, unlike the (^12CH_3) $$_{2}^{{12}}$$ CO…HF complex, the 2ν(^13C=O)/ν(H–F) resonance is virtually absent in the (^12CH_3) $$_{2}^{{13}}$$ CO…HF complex.
Проявление структурных фазовых переходов в кристалле Rb-=SUB=-2-=/SUB=-KLuF-=SUB=-6-=/SUB=- в спектрах комбинационного рассеяния света
Authors: Крылов А.С. , Втюрин А.Н. , Воронов В.Н. , Крылова С.Н.
Published: March 2019

AbstractThe Raman spectra of an Rb_2KLuF_6 crystal are studied in the temperature range from 8 to 375 K, which includes two phase transitions: one of which proceeds from a cubic to a tetragonal phase, while the other transition takes place from a tetragonal to a monoclinic phase. An analysis of the temperature dependences of parameters of spectral lines shows that the former transition is of the second kind, while the latter transition is of the first kind, close to the tricritical point. It is shown that the structural phase transitions in the Rb_2KLuF_6 double perovskite are not associated with disordering. The former transition is associated with rotations of LuF_6 octahedra around the fourth-order axis, while the latter transition is related with rotations of octahedra and displacements of rubidium ions.
О сфероидальной модели рассеяния света несферическими частицами
Authors: Фарафонов В.Г. , Ильин В.Б. , Прокопьева М.С. , Тулегенов А.Р. , Устимов В.И.
Published: March 2019

AbstractWe have constructed a spheroidal model to solve the problem of light scattering by nonspherical particles. The semiaxes of the model spheroid are determined based on the requirement that the volumes of initial and model particles are equal, as well as the ratios of their longitudinal and transverse dimensions. This ensures the closeness of the optical properties of initial and model particles. This approach has been applied to prolate and oblate parallelepipeds, cylinders, and cones with the ratios between their larger and smaller dimensions equal to 2 or 10. The direction of propagation of the incident TE or TM plane wave was either parallel or perpendicular to the symmetry axis of particles and model spheroid. The particle size has been determined by dimensionless parameter $${{x}_{{v}}}$$ = $$2\pi {{r}_{{v}}}$$ /λ, which depends on the particle volume, since $${{r}_{{v}}}$$ is the radius of the equivolume sphere. In calculations, this parameter has been varied from small values to fairly large ones, $${{x}_{{v}}}$$ = 10. The applicability range of the model has been determined by comparing the results of numerical calculations performed by the rigorous separation of variables method for spheroids and the method of discrete dipoles for other nonspherical particles. It has been shown that the applicability range of the model for parallelepipeds, cylinders, and cones is wide enough for different parameters of the problem, in particular, if the parameter $${{x}_{{v}}}$$ ≤ 6, then the relative error of the model does not exceed 10–15%. To a large extent, this is related to the fact that the first maximum of the dependence of scattering factor Q _sca on $${{x}_{{v}}}$$ is similar for particles of different shapes approximated by one and the same model spheroid.
The SMART Framework: Integration of Citizen Science, Community-Based Participatory Research, and Systems Science for Population Health Science in the Digital Age (Preprint)
Authors: Katapally Tarun Reddy
Published: March 2019

UNSTRUCTURED

Citizen science enables citizens to actively contribute to all aspects of the research process, from conceptualization and data collection, to knowledge translation and evaluation. Citizen science is gradually emerging as a pertinent approach in population health research. Given that citizen science has intrinsic links with community-based research, where participatory action drives the research agenda, these two approaches could be integrated to address complex population health issues. Community-based participatory research has a strong record of application across multiple disciplines and sectors to address health inequities. Citizen science can use the structure of community-based participatory research to take local approaches of problem solving to a global scale, because citizen science emerged through individual environmental activism that is not limited by geography. This synergy has significant implications for population health research if combined with systems science, which can offer theoretical and methodological strength to citizen science and community-based participatory research. Systems science applies a holistic perspective to understand the complex mechanisms underlying causal relationships within and between systems, as it goes beyond linear relationships by utilizing big data–driven advanced computational models. However, to truly integrate citizen science, community-based participatory research, and systems science, it is time to realize the power of ubiquitous digital tools, such as smartphones, for connecting us all and providing big data. Smartphones have the potential to not only create equity by providing a voice to disenfranchised citizens but smartphone-based apps also have the reach and power to source big data to inform policies. An imminent challenge in legitimizing citizen science is minimizing bias, which can be achieved by standardizing methods and enhancing data quality—a rigorous process that requires researchers to collaborate with citizen scientists utilizing the principles of community-based participatory research action. This study advances SMART, an evidence-based framework that integrates citizen science, community-based participatory research, and systems science through ubiquitous tools by addressing core challenges such as citizen engagement, data management, and internet inequity to legitimize this integration.
Defeating Patriarchy on Its Own Terms: The Paradox of Female Chastity in Krittivasa’s Ramayana
Authors: Chakravarty Saumitra
Published: March 2019

This essay attempts to analyze the role of women in the Bengali Ramayana of Krittivasa, a regional version of the original Sanskrit epic composed by Valmiki. It does so from the perspective of the strict code of female chastity enshrined in a patriarchal society and enforced upon its women by their male guardians within and beyond the home. While on the one hand, it is an instrument of female subjugation, this essay make an attempt to analyze how the strict observance of this code by the women in the epic, makes it a weapon of female empowerment across the different strata of society through which the text operates. The powerful spiritual energy generated in the process by these women can threaten even the most powerful of patriarchs including the epic hero Rama himself.
AN ANALYSIS OF AUTHENTIC MATERIAL USED IN TEACHING ENGLISH AT SD PURI ASAH DASAR AVESIENA GREEN SCHOOL MALANG
Authors: Primadona. Yuhalisana , Prastiyowati Santi
Published: March 2019

Authentic material is a material which is used by the purpose to imitate the real-world situations. In addition, the use of authentic material is expected to bring the learners into direct contact with a reality so the students will interest during the learning process. However, the objectives of the research were to investigate kinds of authentic material, to explore the implementation of authentic material, to find out the problem faced by the Englishteacher in using the authentic material of SD PuriAsah Dasar Avesiena Green School Malang. Descriptive qualitative research design was used in this study. The techniques in collecting the data were observation and unstructured interview while field notes and interview guide were used as the instruments. The subject of this research was an English teacher of SD PuriAsah Dasar Avesiena Green School Malang. The result of the research showed that there were forty-eight authentic materials were used in five times observations. The researcher classified those varieties of authentic materials into three kinds of authentic materials: by those forty-eight authentic materials, only one referred to Authentic Visual Material, two referred to Authentic Printed Material, and the rest forty-five referred to Realia which meant it was the most favorable Authentic Material used by the English teacher. In using the authentic material, the teacher usually conducted an outdoor class activity to find out the real object related to the topic. By seeing and holding the real thing, it made the students interested and experienced the real situation. In this case, the problem faced by the teacher was in finding the authentic material which adjusted the students’ grade and topic.