bluuebunny/crossref_metadata_2025 huggingface dataset:
Emancipating myself, the students and the language: Brazilian teachers’ attitudes towards ELF and the diversity of English
Authors: Cogo Alessia , Siqueira Sávio
Published: February 2019

A great amount of the findings in ELF research has not yet reached the regular practitioner in different parts of the world. Despite the fact that ELF research has been solidly advancing, very little has been found out about teachers’ questioning their role in the context of ELF, the global position of English, their role in possibly reproducing or resisting discourses of dominance, inequalities, hegemony, among others. This paper investigates teachers’ attitudes towards ELF, and what influences them, with pre- and in-service teachers in Brazil, the former from a public university and the latter from a prestigious language institute located in Salvador, the capital city of Bahia, Brazil. The findings have shown that regardless of the differences in experience and background knowledge, both groups have demonstrated a very positive attitude towards ELF, although many questions and doubts were brought up when it came to conceiving the teaching of ELF-oriented classes on a regular basis. At a broader level, both groups highlighted the link between an ELF-oriented pedagogy and emancipation and open-mindedness, a way of liberating the teachers from the straightjacket of traditional ELT.
Synergistic effect between CO2 and H2O2 on ethylbenzene oxidation catalyzed by carbon supported heteropolyanion catalysts
Authors: Al Kahtani Abdullah , Abduh Naaser A.Y. , Aouissi Ahmed
Published: February 2019

A series of Keggin heteropolytungstate salts (M1.5PW12O40, M=Cu, Co, Zn and Fe) were prepared and characterized utilizing inductively coupled plasma spectrometry (ICP), Fourier transform infrared (FTIR) spectra, and ultraviolet-visible (UV-Vis) light spectroscopy. The as-prepared catalysts were tested for the oxidation of ethylbenzene by using carbon dioxide/hydrogen peroxide (CO2/H2O2) as the oxidizing agent system under solvent-free conditions. The results indicated that the heteropolytungstates catalyzed the side chain oxidation of ethylbenzene leading to acetophenone as a major product. The effect of various reaction parameters on ethylbenzene oxidation over the best catalyst of the series, namely Co1.5PW12O40 loaded on activated carbon (AC), was investigated. It was found that the selectivity depends strongly on the reaction temperature. Higher reaction temperatures reduce the conversion due to the decomposition of H2O2. Oxidation by a large amount of H2O2 decreases the conversion owing to a decrease of the solubility of ethylbenzene in an aqueous medium, and favors the oxidation of the reaction products, which are more soluble in an aqueous medium. The increase of the CO2 pressure improves both the conversion and the selectivity of acetophenone due to the involvement of the percarbonate species (HCO4−) responsible for oxidation by oxygen transfer.
La voz del usuario en la planeación estratégica de bibliotecas públicas usando el Despliegue de la Función de la Calidad (QFD)
Authors: Romo - González José Refugio , Tarango Javier , Machin-Mastromatteo Juan
Published: February 2019

La planeación estratégica ha funcionado tradicionalmente al escuchar la voz de directivos. Además del estudio de sus ambientes y procesos funcionales, esta iniciativa considera como fundamental escuchar la voz del usuario, al valorar que son los que verdaderamente enfrentan las condiciones de la calidad de los servicios bibliotecarios.Por esta razón, se toman como referencia los resultados de un estudio de usuarios, en donde se aplicó la herramienta de Despliegue de la Función de La Calidad (QFD) En bibliotecas públicas del municipio de Chihuahua, México. Ello permitió identificar que la planeación estratégica de bibliotecas en un sistema integral administrativo puede estar sustentada en la gestión de la calidad y en el cuadro de indicadores de desempeño, cuya implantación podrá ser desarrollada bajo un ciclo de diseño, control, mejora e innovación para alcanzar objetivos armónicos y sistemáticos.
Impaired oxidative-antioxidative balance during migraine attack
Authors: Khosravi Alireza , Nakhaee Alireza , Ghoreishi Abdoreza , Arefpoor Zahra , Sadeghi Masoud
Published: February 2019

Background: Recent evidence has suggested that oxidative stress may play a role in the pathophysiology of migraine. In this study, we aimed to evaluate the oxidative-antioxidative status in sera of migraine patients from an Iranian population during migraine attacks.
Methods: This study recruited 46 migraine patients with or without aura and 45 sex- and age-matched healthy controls. The levels of protein carbonyl (PC), malondialdehyde (MDA) and total oxidants status (TOS) were measured as the indicators of oxidative stress. The levels of total thiols (T-SH), reduced glutathione (GSH) and total antioxidant capacity (TAC) were determined as markers of antioxidant status. Oxidative stress index (OSI) was calculated by dividing TOS to TAC.
Results: The serum levels of MDA (4.10 +/- 0.70 vs. 3.20 +/- 0.62, P = 0.003), TOS (18.46 +/- 4.06 vs. 16.21 +/- 3.67, P = 0.007) and OSI (1.54 +/- 0.60 vs. 1.22 +/- 0.46, P = 0.006) were significantly higher in migraine group compared to controls, however, no statistically significant differences of PC levels were found between migraine patients and controls (0.615 +/- 0.161 vs. 0.517 +/- 0.126, P = 0.1). In contrast, the levels of T-SH (273 +/- 51.71 vs. 310.88 +/- 53.32, P = 0.001), GSH (28.08 +/- 6.20 vs. 32.13 +/- 5.8, P = 0.002) and TAC (1.27 +/- 0.226 vs. 1.41 +/- 0.26, P = 0.01) were significantly lower in migraine patients compared to healthy controls.
Conclusion: Our study showed higher levels of oxidative stress and lower levels of antioxidant status in migraine group compared to controls, which indicates the possible role of oxidative stress in triggering migraine attacks.
Facile synthesis and electrical characteristics of n-SnO2/p-NiO nanowire heterojunctions
Authors: Thi Thanh Le Dang , Manh Hung Chu
Published: February 2019

In the current work, we report a facile synthesis of n-SnO2/p-NiO nanowire heterojunctions by a drop-coating approach. The pure SnO2 and NiO nanowires (NWs) were grown by chemical vapor deposition (CVD) and hydrothermal methods, respectively. Morphology, composition and crystal structures of the NWs and heterojunctions were investigated by means of field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The data showed that SnO2 NWs were grown with their average diameter of 200 nm and length of about 10 mm. The NiO NWs were also synthesized with a shorter average length and smaller average diameter compared to those of the SnO2 NWs. The EDS results indicated no impurity present in both SnO2 and NiO NWs. The XRD patterns pointed out the tetragonal rutile and cubic structures of SnO2 and NiO, respectively. Interestingly, electrical properties of the NWs and heterojunctions were studied through the Keithley 2602A sourcemeter-based I-V characterizations. The results confirm the nature of the metal semiconducting oxides. The formation of the n-SnO2/p-NiO heterojunctions was certified through the rectifying behavior of the I-V curves with the rectification ratio of about 5 at ± 3V and 350 oC. The potential energy barrier between the NWs was also estimated to be about 1.16 eV. The band energy structure was also proposed to get insight into characteristics of the n-SnO2/p-NiO heterojunction.
Effects of bottle gourd (Lagenaria siceraria) rootstocks on plant nutrient content of watermelon [Citrullus lanatus (Thunb.) Mats. & Nak.] leaf and nitrogen use efficiency
Authors: YETİŞİR Halit , SARI Nebahat
Published: February 2019

In this study,
rootstock effects of bottle gourds on nutrient uptake and nitrogen use
efficiency of watermelon were investigated. Watermelon seedlings were grafted
onto Birecik, Skopje, Emphasis, 216 and FRGold. Non-grafted plants were used as
control. The seedlings were transplanted and kept under plastic tunnel until
climatic conditions were suitable for watermelon cultivation. Experimental area
was amended with doses of 18 kg N da-1,
20 kg P2O5
da-1 and 18
kg K2O da-1based on soil analysis. No micro-nutrient
fertilizer was applied. While total P and 1/3 of N and K were applied as base
fertilizer before transplanting, the second and third portions of the N and K
were applied 20 and 40 days after transplanting, respectively. The experiment
planned as a completely randomized block design and repeated four times, each
replication has 15 plants. The seedlings were transplanted with 200 x 50 cm spacing. Macro and
micro-nutrient contents were analyzed in fully grown seventh and eighth leaves
from soot tips. While N, P, K and Ca contents of the leaves did not show
significant differences between graft combinations and control plants, Mg concentration
was significantly affected by rootstocks. All graft combinations had higher Fe
concentration in the leaf than non-grafted plants. Cu and Zn concentrations
showed significant variation based on rootstock. Higher nitrogen use efficiency
(ton yield kg N-1) was recorded in all graft combinations as
compared to controls. Bottle gourd rootstocks used in this study enhanced the
nutrient uptake, plant growth and total fruit yield.
THE CONCEPT OF OPTIMAL BAR ROLL PASS DESIGN. REPORT 3. SPACE OF ROLL PASS DESIGN SCHEMES
Authors: Mikhailenko A. M. , Shvarts D. L.
Published: February 2019

Based on the system approach and on the experience accumulated at theoretical data, design and industrial development of bar rolling, the Chair “Metal Forming” of Ural Federal University develops the universal “Concept of optimum calibration”. The general ideology of roll pass design optimization is stated in article “The concept of optimal bar roll pass design. Report 1. Basic statements”. In the article “The concept of optimal bar roll pass design. Report 2. Calibers space” the structure, appointment and maintenance of the information block reflecting so-called “calibers space” are considered. According to the general concept of optimization, the following task that needs to be solved is the problem of creation of information block so-called “space of schemes of roll pass design” which will be used further as the first space of optimization. The concept “space of schemes of roll pass design of a bar-rolling mill” is considered as the space containing all possible virtual schemes of rolling of a concrete profile on the concrete rolling mill. For formation of the space of schemes of rail calibrations it is necessary to generate separate virtual schemes and to consistently fill this space with them. Thus, the space of calibrations schemes is formed of separate unique calibrations schemes. For formation of this space from separate calibers, it is offered to use the specialized algorithms which are “generators of schemes of roll pass design”. As an example, the structure of the generator prepared for creation of such space for rolling of railway rails is considered. It is revealed that all known rail calibrations can be presented in the form of essentially the same block structure which is used as the central element of the schemes generator of rail calibrations. Usage of described and similar generators in relation to rolling process of a concrete profile on the concrete rolling mill allows obtaining spaces of acceptable schemes of calibrations. Such spaces are necessary for the subsequent optimizing procedures for search of the best calibration scheme from all possible calibrations. The considered approach for creation of calibrations schemes space can be used during creation of computer-aided engineering systems and optimization of calibrations of rolling rolls.
ESTIMATION OF STRUCTURAL SENSITIVITY OF PIPE STEELS ULTIMATE STRAIN TO PIPELINES SERVICE LIFE USING COMPLEX ENERGY CRITERIA OF SYNERGY FRACTURE
Authors: Skudnov V. A. , Safronov A. S. , Khlybov A. A.
Published: February 2019

The article gives an overview of well-known hypotheses and theories on ultimate state of metals. Processes in metals when stress is applied are described. Multifunctional equation for ultimate strain dependence from density (opening) is offered with all the factors of metal’s ultimate state before fracture. Phases of the fracture of deformed polycrystal structure are specified. An equation is presented that relates the ultimate deformation of a metal to fracture with all the characteristics that determine the limiting state of the metal. Two- or three- compound energy failure criteria equations used for quality estimation of metal structure and performance when main pipeline operating are given for such criteria as energy capacity, crack initiation, crack proliferation, fragility and scale. The fracture criteria calculation for Kh70 steel samples of pipes after operation for 5, 20 and 24  years was made as an example. The comparative analysis of complex fracture criteria values for Kh70 steel pipelines of different lifespans has been carried out. After 5, 20 and 24 years of usage mechanical characteristics of steel Kh70 of main pipelines haven’t changed dramatically, and fracture criteria are inclined to decrease from 21 to 48.5  %, crack proliferation and fragility criteria are the most changeable. At mesolevel the nature of crack initiation is the same for all classes of steel. Under the influence of operating loads, energy intensity, i.e. the ability of metal to withstand any loads with increasing service life is significantly reduced, which is confirmed by the change in the fracture criteria considered in the article. It is shown that the fracture criteria can be used to predict the performance of pipeline steels after a long period of operation.
DESIGN IMPROVEMENT AND OPERATION MODELING OF EAF GAS EXHAUST SYSTEM OF A FOUNDRY SHOP
Authors: Eron’ko S. P. , Gorbatyuk S. M. , Tkachev M. Yu. , Oshovskaya E. V.
Published: February 2019

As a result of a survey of gas exhaust systems of low-tonnage electric arc furnaces (from 3 to 10 tons) operated in the foundries of machine-building enterprises, the bottlenecks were identified, due to which a large amount of gas-dust emissions gets into the production rooms and pollutes the air in the working areas. First of all, it occurs due to the design schemes imperfection of the evacuation systems of gas and dust ejected from the furnace cavity through the outlet channel, the working window, gaps between its body and the roof, between edges of the holes in its upper part and the electrodes lowered through them. In particular, joint units of the rotary collection hoods with the gas exhaust pipelines in these systems do not provide proper sealing of movable joints. In this regard, the authors have proposed an improved design of rotation mechanism of the furnace collection hood, which involves the use of two sand gates. These gates eliminate the possibility of harmful emissions release between movably connected elements of the system into the environment. To begin designing of the industrial sample of a modernized mechanism, a method for calculating the energy-power parameters of its drive has been developed. A preliminary validation of the correctness of the taken technical decisions and of the obtained calculating dependencies was performed on the operating model of the investigated system manufactured on a 1:10 scale relative to the industrial sample. For the model research an instrumentation complex that included strain gauge transducer, AC amplifier, analogto-digital converter and computer was used. During this research the load acting on the model drive of the collection hood rotation mechanism when it was transferred from the working position to the parking one and back was fixed. At the same time, the load was measured for two cases: in the absence and in the presence of sand in the gates which ensure sealing of the movably joint elements of the investigated mechanical system. It was established that the portion of resistance forces arising in two sand gates during relative rotation of the moving element is 20  –  26  % of total load on the mechanism drive depending on angular velocity of the cantilever with collection hood. Similarly, this indicator calculated from obtained theoretical dependences was in the range of 17  –  23  % for the rotation mechanisms of collection hood of arc furnaces with a tonnage of 3 to 10  tons. Video filming of the smoke movement patterns, which flows from the furnace model through the existing gaps between its body and roof during the steelmaking process imitating, confirmed the reliability of the sand gates that provide complete sealing at the joint units of the moving parts of the collection hood rotation mechanism. Practical use of the proposed technical solution allows increasing of efficiency of evacuation of the harmful gas and dust emissions from the working zone of smelting furnaces used in the foundry.
VOLUMETRIC CHANGES AT HEATING IN STEEL 60Si2CrV SUBJECTED TO Q&P TREATMENT
Authors: Zurnadzhi V. I. , Efremenko V. G. , Brykov M. N. , Gavrilova V. G. , Tsvetkova E. V.
Published: February 2019

The paper presents results of the investigation of phasestructural transformations and volumetric changes that occur during heating in high-silicon spring steel 60Si2CrV subjected to Q&P(quenching and partition) treatment. Chemical composition of the steel was: 0.53  %  C; 1.46  %  Si; 0.44  %  Mn; 0.95 % Cr; 0.10 % V; 0.016 % S; 0.013  %  P. Steel samples were subjected to Q-n-P treatment as follows: a) austenitization at 880  °C; b) quenching with the cooling stop at 120, 160, 200 and 240  °C; c) subsequent holding at 220, 250 and 300  °С with duration from 10 to 3600  s; d) final cooling in water. The volumetric changes during heating were studied using an optical differential dilatometer at a heating rate of 1  K/s. As a reference, a sample of the same steel stabilized by high tempering was used. The amount of retained austenite was determined by X-ray diffraction using a diffractometer DRON-3 with Fe-radiation. It is found that on the heating curves of Q&P samples, the sections corresponding to different transformations during tempering are clearly identified. On dilatograms of the Q&P samples, dilatometric effect corresponding to the second transformation during tempering (270  –  430  °C) was found to be increased dramatically, indicating an increase in retained austenite amount compared to the quenched state as a result of Q&P treatment (as confirmed by Xray study). At the same time, value of the effect corresponding to the third transformation during tempering was found to be decreased. To obtain the maximum amount of retained austenite in 60Si2CrV steel, the partitioning temperature should be of 260  –  300  °С, while the quenching completion temperature should be of 160  –  240  °С. The amount of retained austenite rises substantially as the quenching temperature increases. Duration of the partitioning stage should be selected taking into account the extreme character of austenite dependence on the partitioning time. As a result of the work, an effective applicability of the dilatometric method for analyzing the steel structural state and choosing the optimal mode of Q&P treatment was demonstrated.
CORROSION AND CAVITATION RESISTANCE IN SEAWATER OF CHROMIUM–NICKEL–MANGANESE HIGH-STRENGTH NITROGEN AUSTENITIC STEELS
Authors: Kaputkina L. M. , Svyazhin A. G. , Smarygina I. V. , Kindop V. E.
Published: February 2019

Corrosion and cavitation resistance in seawater of high-strength economically alloyed nitrogen chromium–nickel–manganese steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N is experimentally studied compared to chromium-nickel steels Cr18Ni9 and Cr18Ni9N. Tests for resistance to pitting corrosion were carried out according to the chemical method in the test solution 100 g/l FeCl3 ·6H2 O. Resistance to general corrosion was assessed by tests in synthetic seawater (3  %  NaCl). Test for cavitation resistance in seawater was performed using a research stand of high-intensity cavitation effects with the use of ultrasonic devices UIP 1000  hd Hielscher Ultrasonic in 3  %  NaCl solution in water at a frequency of 20 kHz, a power of 1000  W and amplitude of 25 microns for 8  –  36  hours. The extent of damage and change in the surface microhardness, change in the phase composition and mass of the samples were assessed after cavitation. It is shown that steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N are more susceptible to pitting in seawater and in solution of ferric chloride, and have the general corrosion rate lower than that of chromium-nickel steels type Cr18Ni9. It is shown that ultrasonic cavitation can not only lead to surface damage due to erosion, enhance local corrosion, but also to changes in their physico-mechanical properties by strain hardening and phase transformations. Steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N with thermally and mechanically stable austenite are more resistant to ultrasonic cavitation in the seawater in comparison with chromium-nickel steels, especially those with less strength and less resistant steel Cr18Ni9. So subjected to cavitation in the seawater for 36 hours, samples of chromium-nickel steels Cr18Ni9 and Cr18Ni9N had a significant change in their condition: significant damage (etching) and surface hardening, and there was formation of a small amount of martensite in steel Cr18Ni9. Samples of steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N had only minor changes in surface conditions and hardening of the surface layers.
MENDELEEV VIEW ON URAL FERROUS INDUSTRY OF THE END OF 19th CENTURY
Authors: Schastlivtsev V. M.
Published: February 2019

The article presents conclusions of the commission, headed by D.I. Mendeleev, directed at the end of the 19th century to the Urals, to find out the reasons for the lag of Ural metallurgical industry from the growth of this industry in Southern Russia. The commission examined the iron ore base of the Urals, its timber reserves and the ways of its delivery to the plants, and established the type of plant owners. Important conclusions were made about the further development of industry.
FORMATION OF TEMPERATURE FIELDS AND THERMAL STRESSES ARISING DURING SOLIDIFICATION OF CYLINDRICAL CONTINUOUSLY CAST STEEL BILLETS
Authors: Krayushkin N. A. , Pribytkov I. A. , Shatokhin K. S.
Published: February 2019

The article presents investigation results of the effect of inhomogeneity of boundary conditions on the intensity of metal cooling in the process of continuous casting of cylindrical billets from corrosionresistant steels. It is assumed that the boundary conditions are nonuniform along the billet perimeter. In the longitudinal direction, the cooling intensity is assumed to be constant within the cooled sector of the billet. During the research it was believed that there are flows of thermal energy between the cooling sectors. A comparative analysis of temperature gradients and resulting thermal stresses in the solidified billet at different cooling intensities realized in the secondary cooling zone was carried out The values of thermal stresses are compared with the maximum permissible for each grade of steel in order to find those cooling conditions in which the thermal stresses do not exceed the permissible values. Based on the results obtained, conclusions are drawn about the effect of cooling intensity on the occurrence of external and internal defects in the resulting cylindrical continuous cast billets. The authors have also made the conclusions about the effect of inhomogeneity of the boundary conditions on the formation of temperature fields in a solidified cylindrical continuously cast billet. The results of the conducted studies are presented in a graphic form and their detailed analysis is carried out. To calculate the temperature fields in the solidifying billet, a specially developed mathematical model was used, based on the equation of nonstationary heat conductivity. For the calculation of thermal stresses, known mathematical formulas have been used that allow calculating the values of thermal stresses arising between cooling zones in the solidifying billet during the continuous casting of steel. The obtained data are of high practical importance, since they can be used to develop rational cooling regimes, in which excess permissible thermal stresses will not be observed. This, as a consequence, will reduce the number of internal and external defects arising in the solidifying continuously cast billet.
DEFORMATION AND FRACTURE OF STRENGTHENED HIGH-CARBON STEEL AFTER TREATMENT IN TEMPERATURE CONDITIONS OF PHASE PRE-TRANSFORMATION AND TRANSFORMATION
Authors: Murav’ev V. I. , Bakhmatov P. V. , Lonchakov S. Z. , Frolov A. V.
Published: February 2019

Traditional methods of heat treatment are energy-intensive and time-consuming, so the task of increasing their efficiency is very relevant. The process of repeated high-speed heating with short-term aging in the temperature range of polymorphic pre-transformation and transformation from the viewpoint of evolution of structure, properties and character of the fracture of quenched high-carbon steels was investigated. In particular, it was found that high-speed heating (600  –  700  °C/s) and short-term holding (0.5  sec) followed by cooling in salted water (6  °C) leads to the formation of a structure not differing from the structure of low-drawn (200  °C, 2  hours) martensite of traditionally hardened steel with 4 times increase in elongation and 2  times contraction while maintaining strength during the tensile test. Short-term aging of 8  –  15  –  25  seconds with repeated quenching of high-carbon steels from 820  °С in cold salted water (6  °С) leads to formation of the structure of ultra-fine-lamellar, submicroplast, globular perlite. There is a three-dimensional nanostructuring of steel that differs from traditional hardening with high temperature tempering by the structure and properties: magnitude of the applied stresses, both at deformation stages and at fracture (increase in σ by 55  %, in σ0.2 – by 17  %, in ψ  –  8  times, in αn  –  by 80  %). Increase in short-time holding up to 40  –  50  sec, with repeated quenching from 820  °C leads, in contrast to the traditional one, to formation of the structure of ultra-small-malt martensite and to appearance in fracture on the slip planes of the patching structure, resembling a honeycomb in shape. After the low temperature tempering during the tensile test, all stages of deformation are presented. In fracture the crushing of pit structure and the absence of brittle tunnel pits are observed, plasticity is improved (δ  ~  1.5  times, ψ  –  3  times) at strength preservation.
METHOD OF THE RESEARCH OF OXIDIZABLE METAL HEATING BY SOFTWARE SUITES OF ENGINEERING ANALYSIS
Authors: Denisov M. A. , Chernykh V. N.
Published: February 2019

The article is devoted to the development of a method for modeling the heating of oxidized metal billets, in which the dimensions and thickness of the scale layer vary with time. The approach used in this development facilitates the appliance of modern software packages for the analysis of objects with varying geometry; and due to this the complexity of developing mathematical models of several metallurgical processes can be dramatically reduced. To simulate the process of metal oxidation, the method of equivalent thermal conductivity was used. The experimental verification of the method is performed and the possibility of its use for improving the methods of controlling the processes of industrial heating is shown. This method was worked out during experiments on the furnace №3 with walking beam of the mill 150 at Nizhne-Serginsk Hardware and Metallurgical Plant. Calculations were made to determine the thickness of the scale layer, which varies with time; the corresponding dependencies were constructed. The problem was solved by ANSYS Multiphysics software package as a problem of non-stationary heat conduction with boundary conditions of the first kind. During modeling, a finite-element grid was constructed, sufficiently detailed to obtain reliable results and, at the same time, allowing to solve the problem on low-power computers. In the course of solution, a number of simplifications were applied, in particular, simplification of the computational algorithm, in which the thickness of the scale layer is uniquely determined by surface temperature of the billet. Temperature distribution along the billet’s thickness was determined. Graphs and isotherms were constructed to compare values of the temperatures in metal and in scale layer. Also, a comparison of the temperature differences in the scale layer determined by the calculation method was made for the furnace and experimental conditions. In this study, the problem is considered as nonstationary, with varying boundaries. The research object is preparation of the metal (real solid) with scale layer, increasing with time. When solving a problem, this real solid was replaced by a conditional one with constant averaged dimensions. According to the equality of thermophysical processes, properties of the conditional solid were determined, whose change is equivalent to the dimensions of the real solid.
COLD RESISTANCE AND MECHANICAL PROPERTIES OF HIGH-STRENGTH MEDIUM ALLOY STEEL DEPENDING ON THE TECHNOLOGY OF CAST BILLETS PRODUCTION
Authors: Chernyshov E. A. , Baev I. M. , Romanov A. D. , Romanova E. A.
Published: February 2019

Experimental data on influence of conditions of high-strength steel crystallization on its mechanical properties are given in the work. Special attention is paid to the cold resistance as to the most important indicator of operation properties of the responsible products defining reliability and operability of a cast final product. Serial curves of impact strength, work of crack development and percent of fibration are given depending on test temperature. The possibility of increase in cold resistance of the cast alloyed steel is shown depending on casting technology: in a volume sandy form (control casting), in a thin-walled form with the ceramic layer and compulsory cooling with air-and-water mix differentiated on height (with external cooling) and in the same form with input of microrefrigerators when filling liquid steel (with complex impact). According to the research results it was established that the impact strength of the experimental metal obtained at complex impact on the hardened metal is higher in all studied temperature interval. Distinctive feature is smoother change nature of impact strength of experimental metal and lack of sharp reduction of this indicator for control samples. Change of work of crack development also depends on conditions of crystallization and cooling of casting metal. Serial curves have shown that tested metal has smaller tendency to fragile destruction (higher cold resistance). Similar dependences are received during the research of break fibration.
SLAGS OF THE METALLURGICAL PLANTS OF ARMENIA AT FINE GRINDING
Authors: Martirosyan V. A. , Sasuntsyan M. E.
Published: February 2019

In connection with the development of copper and molybdenum production in Armenia, it becomes necessary to develop a technology for processing the slags of the functioning metallurgical plants to extract valuable metals from these slags. It concerns the copper slags of Alaverdi Copper-Smelting Plant with a content of FeO ~50  % and the molybdenum slags of Yerevan “Pure Iron” Plant with a content of SiO2 ~80  %. These slags are obtained at high temperatures (with FeO·SiO2 , CaO·SiO2 , Fe3 O4 ) and, therefore, they are less active to be used later. Meanwhile, the mentioned slags are rich in iron and silicon oxides and can serve as a cheap raw material for producing iron silicides. The iron silicides can be used in micro- and nanoelectronics, as well as in metallurgy as an alloying additive in the production of steels of special physical and chemical properties. The production of such valuable silicides from an inexpensive raw material is important for Republic of Armenia and is of not only economic, but also ecological significance. To obtain iron silicides, a method of combined aluminothermal reduction of primarily mechanoactivated copper and molybdenum slags is proposed. The preliminary mechanoactivation allows to purposefully affect the structure of the reaction mixture and parameters of the self-propagating high-temperature synthesis (SHS), thus ensuring the possibility of regulating the structure and phase composition of the synthesized silicides. This work considers issues on the impact of transformation and phase formation on the morphology of slags of copper and molybdenum production in the functioning Armenian metallurgical plants at mechanochemical activation by the method of fine grinding in a vibromill. It is shown that at fine grinding (up to 10  mcm), the slags, containing small-reactivity complex compounds of iron and silicon (fayalite, magnetite, quarzite) undergo profound chemical changes, transforming into amorphous oxides. The obtained activated oxides can serve as a raw material for producing iron- and silicon-containing alloys – iron silicides.
During data acquisition v10
Authors: Snoek Lukas , Beemsterboer Tinka
Published: February 2019

This protocol lists all the steps necessary to run your MRI experiment/data acquisition safely and in a way that yields high-quality data. Moreover, if you use the centre's QC/preprocessing service, it lists the steps necessary to make sure we can convert the data into BIDS and run them through the QC/preprocessing pipelines.
Grade Level Differences in the Cognitive, Behavioral, and Physiological Components of Test Anxiety
Authors: Aydın Utkun
Published: February 2019

The capacity to cope with test anxiety that contain high concentrations of cognitive, behavioral, and physiological manifestations, is becoming increasingly important in educational contexts as well as evaluative settings. The developing ability to deal with test anxiety relative to the increasingly strict evaluative practices students encounter points that students’ test anxiety may decline as they move through school years. This study examined three test anxiety components (thoughts, off-task behaviors, and autonomic reactions) with students from 3 public schools in İstanbul, Turkey. Using a diverse sample of elementary (Grade 4; N = 414) and middle (Grade 6; N = 201) school students, grade level differences in these components were investigated. Applying a multivariate approach, significant differences were found in the overall test anxiety, favoring fourth grade students. The results also revealed Grade 4 advantage for off-task behaviors and autonomic reactions, = .014 and = .011, but no grade level differences in the thoughts. Educational implications of the findings are discussed.
Predicting Procrastination: The Role of Academic Achievement, Self-efficacy and Perfectionism
Authors: Kurtovic Ana , Vrdoljak Gabrijela , Idzanovic Anita
Published: February 2019

The aim of this study was to examine the relations of academic achievement, self-efficacy, and perfectionism with procrastination in University students, and to examine whether procrastination can be predicted by academic achievement, self-efficacy, and perfectionism dimensions. 227 University students from different faculties completed Tuckmans' procrastination scale, Almost Perfect Scale – Revised (APS-R; Slaney Rice, Mobley, Trippi, & Ashby, 2001) and General self-Efficacy Scale (GSE; Schwarzer & Jerusalem, 1995), as well as data about academic achievement at the end of last academic year. Results have shown negative correlations of academic achievement, self-efficacy and adaptive perfectionism with procrastination, and a positive correlation between maladaptive perfectionism and procrastination. Results have also shown that self-efficacy is positively correlated with adaptive perfectionism and negatively with maladaptive perfectionism. Maladaptive perfectionism was a positive predictor of procrastination, while academic achievement, self-efficacy and adaptive perfectionism were all negative predictors. Finally, we used Hayes bootstrapping method to examine possible mediations. The results have shown that self-efficacy, by its self, is not a significant mediator, while paths containing self-efficacy and adaptive or maladaptive perfectionism mediate the relation between academic achievement and procrastination. Furthermore, both adaptive and maladaptive perfectionism mediated the relation between self-efficacy and procrastination.
Effectiveness of a Program Based on A Multi-Sensory Strategy in Developing Visual Perception of Primary School Learners with Learning Disabilities: A Contextual Study of Arabic Learners
Authors: K Alenizi Mogbel Aid
Published: February 2019

The current study aims to assess the effectiveness of a program based on a multi-sensory strategy in developing of visual perception for primary school learners with learning disabilities. The study employed the quasi-experimental method on the experimental group of learners. A training program based on multi-sensory strategy was employed on a group of third and fourth graders (n = 30) who were exposed to draw upon their sensorimotor memories and familiarities to recognize the mentally stimulating texts. The other group of 30 learners i.e. the control group was exposed to the regular reading comprehension instructions. Pre-to-post test differences were examined in terms of the learners’ visual perception to evaluate the teaching’s effectiveness. The results illustrates that there is a difference in the level of visual perception skills of the learners of both groups. And the differences were in favor of multi-sensory strategy. The findings of this study suggest that it is constructive for learners to connect their sensorimotor experiences to the text/or the reading materials they are exposed to.
Developing School-relevant Language and Literacy Skills through Dialogic Literary Gatherings
Authors: Lopez de Aguileta Garazi
Published: February 2019

Research in the field of educational linguistics has found that low levels of academic language development negatively affect children’s language, reading and writing skills and, therefore, academic achievements. This is more noticeable in students from low SES backgrounds, who traditionally have a lower exposure to academic language. Nevertheless, dialogic learning environments such as Dialogic Literary Gatherings (DLGs), a worldwide educational practice where participants read and debate literary classics in an egalitarian dialogue, contribute to the appearance of school-relevant language and literacy skills. Although multiple studies on DLGs have shown their impact in different levels, including improving vocabulary and reading skills, the emergence of such skills has not been studied in depth yet. This exploratory study aims to analyze the emergence of academic language and literacy skills in 19 students between the ages of 11 and 13 studying in a school in Spain with over 90% immigrant students. Results show that the egalitarian dialogue in which DLGs are based favors the emergence of school-relevant language and literacy skills, such as judgements and arguments, referential links, or connectives.
Pedagogical design capacity of lower-secondary mathematics teacher and her interaction with curriculum resources
Authors: Jukic Matic Ljerka
Published: February 2019

Various curriculum resources emerged in the last decades, but the textbook still remains the most used teaching and learning resource in mathematics classrooms. In this paper, we use a case study to analyze teaching practice of one math teacher. The aim of the study is to examine how math teacher interacts with the textbook and teacher guide, especially when teacher offloads on those resources, adapts them or improvises in the classroom. The study was conducted using lessons observations and semi-structured interviews. The results showed that teacher does not favour particular type of resource mobilization. Her interaction with resources can be characterized as a dynamic interplay, where type of resource mobilization exchange between the lessons and within a lesson as well. Moreover, teacher’s mobilization of textbook and teacher guide depends on teacher’s goals and assessment of the most pedagogically beneficial instruction for students.
Students´ reasoning on multiplication in primary school classroom context
Authors: Kaufmann Odd Tore
Published: February 2019

This article investigates how students in third grade discuss and reason on multiplication when they first encounter that concept in the classroom context. By analysing the data from 24 classrooms focused on teaching and learning multiplication, the article aims at contributing to the research and conceptualisations about students´ reasoning and strategy use in multiplication. The analysis shows that some of the features within previous research are helpful in characterizing the students´ reasoning about multiplication. However, the data material also reveals new aspects of students´ reasoning multiplication in classroom settings. One aspect is how students reason about different characteristics of multiplication, and reason about the concept of multiplication in a more general way. They put it in a broader context by going beyond the actual example in which the activity takes place. The students have moved away from the actual example, shifting their attention towards a focus on mathematical relationships. Another aspect is how a strong emphasis on using addition when they work with multiplication, by for instance that some students may begin to use different sub-totals, can cause tensions in the discussions between the teacher and students. Results are discussed in relation to previous studies of students´ multiplicative reasoning and implications for practice are elaborated upon.
List of Reviewers
Authors: Diez Palomar Javier
Published: February 2019

This is the list of reviewers.
Cilt kanserlerinde lenfosintigrafi ve cerrahi gama prob ile sentinel lenf nodu biyopsisinin minimal invaziv cerrahi yaklaşımındaki rolü
Authors: GÜNEY İsa Burak , KÜÇÜKER Kadir Alper
Published: February 2019

Amaç: Sentinel lenf nodu(SLN) biyopsisi prosedürü tümörün lenfatik sistem boyunca bir sıra içerisinde ilerlediği görüşünden gelişmiştir. SLN biyopsisinin uzun dönem terapötik kazancı henüz tam olarak aydınlanmamış olsa da bu prosedür lenfatik disseksiyon ve onun lenfödem gibi komplikasyonlarından korunulması gereken lenfatik metastazı olmayan hastaları, komple lenfadenektomi ve adjuvan kemoterapi gibi ek tedavilerden fayda görecek lenfatik metastazı olan hastalardan ayırmamızı sağlar. Bu çalışmada, lenfosintigrafi ile SLN biyopsisinin hasta yönetimindeki rolünü saptamayı amaçladık.Yöntemler: Çalışmamıza 25 cilt kanserli hasta (16 malign melanom, 9 epidermoid karsinom) dahil edildi. Operasyon günü tüm hastalara Tc-99m Nanokolloid intradermal enjeksiyon ile uygulandı. Preoperatif lenfosintigrafi sırasında sentinel lenf nodlarının derideki izdüşümleri işaretlendi. İşaretleme sonrası hastalar operasyona alındı. Cilt üzerinde izdüşümleri işaretlenmiş lenf nodları intraoperatif gama prob ile tespit edilip eksize edildi. Tüm sentinel nodlar histopatolojik inceleme için çıkartıldıktan sonra sentinel lenf nodlarının çıkartıldığı yataktaki rezidüel radyoaktivite sayımının rezeke edilen en yüksek aktiviteli nodun aktivitesinin %10’unun altına düşmesine dikkat edildi.Bulgular: Toplam 86 adet SLN, 54 adet non-SLN cerrahi olarak çıkartılıp, tüm nodlar histopatolojik inceleme için Patoloji Bölümüne gönderildi. Dört hastada sentinel lenf nodlarında metastaz tespit edildi. Bu hastalar geniş cerrahi için elektif şartlarda tekrar operasyona alındı.Sonuç:Lenfosintigrafi ve intraoperatif gamma prob ile lenfatik haritalama yöntemi yüksek bir spesifisite ve sensitivite oranına sahip olup morbiditeyi minimalize etmektedir. Bu yöntemin, mikrometastazları saptaması, olası metastaz yollarını ortadan kaldırması, evreleme ve adjuvan tedaviye yol göstermesi nedeniyle malign deri tümörlerinde rutin olarak uygulanması gereken bir yöntem olduğu düşünüldü.
Compliance to guidelines in in-hospital cardiopulmonary resuscitation interventions: single-center experience
Authors: ÇALIŞKAN Nail , DURUKAN Polat , BAYKAN Necmi , KAYMAZ Nesıj Doğan , ELMALI Ferhan , KAVALCI Cemil
Published: February 2019

Purpose: The aim of this study was to investigate standard of knowledge about adult cardiopulmonary resuscitation according to current guidelines and affecting factors among clinicians working at the Hospital of Erciyes University, Medicine School.Materials and Methods: The study conducted on residences and subspecialty residences who accepted to participate and complete the survey. Overall 303 clinicians who accepted to participate and were accessible for completion of survey were recruited to the study.  The survey included 2 sections. The first section included data regarding demographic characteristics and the second part included 20 multiple-choice items with one correct answer prepared based on 2010 American Heart Association Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.. Results: Age, total duration of medical practice and residency positively affected standard of knowledge. Higher number of cardiopulmonary resuscitation performed within prior 6 months and defibrillation performance during cardiopulmonary resuscitation positively affected standard of knowledge. Post-graduate theoretical and practical training positively affect standard of knowledge. Conclusion: Cardiopulmonary resuscitation trainings aiming clinicians should be standardized and updated as well as education during employment should be scheduled to provide access to such programs.
Morphological evaluation of terminal branches of the facial nerve within the parotid gland in fetus cadavers
Authors: ERTEMOĞLU ÖKSÜZ Canan , KALAYCIOĞLU Ahmet , UZUN Özlem , KALKIŞIM Şahi Nur
Published: February 2019

Purpose: The aim of present study was to describe the branching pattern of the facial nerve according to interconnections between the branches, to examine the number of terminal branches, to determine anatomical variations and to emphasize the importance of these in terms of pediatric parotid surgery.Materials and Methods: Thirty-two parotid regions from eight female and eight male fetus cadavers (gestational ages between 21.0 and 35.5 weeks according to foot lengths) were dissected. The branching pattern of the facial nerve, terminal branch numbers and interconnections between the branches were examined and described.  In present study, the facial nerve was classified using Davis et al.’ classification. But, we encountered interconnections between facial nerve branches that were not mentioned previously and the branching patterns formed by these interconnections were named as Type x and Type y.Results: Out of the total 32 cases, 13 (40.63 %) were Type I, 7 (21.88 %) were Type II, 3 (9.38 %) were Type III and 5 (15.63 %) were Type VI. Type IV and Type V were not encountered. Type x were in 2 (6.25 %) cases and Type y were in 2 (6.25 %) cases. The mean total number of nerve terminal branches was 7.90 ± 1.49.Conclusion: Investigation outcomes presented in this study have defined branching pattern and anatomical variations of the facial nerve branches and can be assist with the protection of the nerve during surgical procedures and prevent surgery-associated damage to the nerve, and thus facial paralysis.