bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pengembangan Alat Peraga Pada Materi Tekanan untuk Siswa SMP dalam Melatihkan Keterampilan Proses Sains
Authors: Dewi Ayu Rusmala , Wati Mustika , Mastuang Mastuang 
Published: April 2019

Abstrak: Media pembelajaran berupa alat peraga yang belum digunakan secara maksimal dan belum terintegrasi secara keseluruhan dengan beberapa fungsi percobaan yang dikemas secara rapi menjadi satu. Oleh karena itu dilakukan penelitian dan pengembangan alat peraga tekanan untuk melatih keterampilan proses sains siswa. Penelitian ditujukan untuk menghasilkan alat peraga tekanan dan mendeksripsikan kelayakan yang meliputi: 1) validitas alat peraga dilihat dari penilaian validator, 2) kepraktisan alat peraga dilihat dari respon siswa, 3) efektivitas alat peraga dilihat dari hasil belajar siswa pada aspek pengetahuan, dan 4) pencapaian keterampilan proses sains siswa dengan menggunakan lembar kerja siswa. Penelitian ini menggunakan model pengembangan ADDIE (Analysis, Design, Development, Implementation, and Evaluation) dengan subjek uji coba pada 32 siswa kelas VIII-D SMP Negeri 11 Banjarmasin. Teknik analisis data menggunakan teknik deskriptif kuantitatif. Hasil penelitian menunjukkan 1) validitas alat peraga termasuk dalam kategori sangat valid dengan skor 4.44, 2) kepraktisan alat peraga termasuk dalam kategori praktis dengan skor 76.6, 3) efektivitas alat peraga termasuk kategori sangat efektif dengan N-Gain 0.71, dan 4) pencapaian keterampilan proses sains siswa termasuk kategori sangat baik dengan rata-rata 85.79. Hasil tersebut menunjukkan bahwa alat peraga layak digunakan untuk melatihkan keterampilan proses sains siswa SMP kelas VIII. Abstract: Props that have not been used optimally and have not been fully integrated with several experimental functions that are neatly packaged together. Therefore research and development of pressure props are carried out to train students' science process skills. The research is aimed at producing of pressure props and describing feasibility which includes: 1) the validity of the props viewed from the validator's assessment, 2) the practicality of the props viewed from the students' responses, 3) the effectiveness of the props viewed the student learning outcomes in the knowledge aspects, and 4) achievement of students' science process skills using student worksheets. This study uses the ADDIE development model (Analysis, Design, Development, Implementation, and Evaluation) with the subject of the trial on 32 students of class VIII-D of SMP Negeri 11 Banjarmasin. The data analysis technique uses quantitative descriptive techniques. The results showed 1) the validity of the props included in the very valid category with a score of 4.44, 2) the practicality of the props included in the practical category with a score of 76.6, 3) the effectiveness of the props included in the very effective category with N-Gain 0.71, and 4) achievement of skills Science process students include very good categories with an average of 85.79. These results indicate that appropriate teaching aids are used to train science process skills of class VIII junior high school students.
Analisis Respon Siswa terhadap Penggunaan KIT Kalorimeter dalam Pembelajaran IPA Pokok Bahasan Kalor
Authors: Hasyim Faiz 
Published: April 2019

Abstrak: Penelitian ini bertujuan untuk melihat respon siswa terhadap penggunaan KIT Kalorimeter dalam pembelajaran IPA pokok bahasan kalor. Metode yang digunakan dalam penelitian ini adalah deskriptif kualitatif. Subjek penelitian ini adalah 25 siswa kelas 7 MTs Alif Laam Miim Surabaya. Instrumen penelitian ini adalah angket. Hasil penelitian ini adalah rerata respon siswa terhadap penggunaan KIT Kalorimeter dalam pembelajaran IPA pokok bahasan kalor sebanyak 94%. Rerata prosentase sebesar 94% didapat dari prosentase pernyataan pertama sebanyak 95%, pernyataan kedua sebanyak 97%, pernyataan ketiga sebanyak 97%, pernyataan keempat sebanyak 87%, pernyataan kelima sebanyak 93%, dan pernyataan keenam sebanyak 93%. Berdasarkan prosentase tersebut, siswa menyatakan sangat setuju terhadap semua pernyataan yang diajukan terkait penggunaan KIT Kalorimeter dalam pembelajaran IPA pokok bahasan kalor. Hal ini menunjukkan bahwa penggunaan KIT kalorimeter dalam pembelajaran IPA untuk menjelaskan pokok bahasan kalor sangat diminati oleh siswa. Abstract: This research is intended to find out students' responses towards the use of props Kalorimeter in studying the subject of Science under the topic of heat. The method used in this research is descriptive qualitative. The subjects were 25 students in class 7 MTs Alif Laam Miim Surabaya. The instrument used was the questionnaire. The result of this research shows that the average score of students' response is 94%. That percentage was taken from the average of the percentages of the 1st statement (95%), 2nd statement (97%), 3rd statement (97%), 4th statement (87%), 5th statement (93%) and the last one, the 6th statement (93%). Based on the score, students agreed with all statements stated in the questionnaire. It showed that the use of props Kalorimeter in studying science under the topic of heat was interested in the students.
Technological features of production of copper-based composites reinforced with cast iron granules by means of casting
Authors: Kalinichenko A. S. , Sheinert V. A. , Kalinichenko V. A. , Slutsky A. G. 
Published: April 2019

Increasing the operational reliability of friction units is one of the priorities for mechanical engineering, which requires the creation of effective tribotechnical materials. First of all, this applies to sliding bearings, which are used in various friction units in a wide range of operating conditions and must meet a number of requirements: low coefficient of friction, high wear resistance and fatigue resistance, as well as good thermal conductivity, workability, corrosion resistance and machinability, low coefficient of linear expansion and low cost. It is problematic to satisfy these requirements in real conditions; therefore, different friction materials that are best suited to specific conditions have been developed. In particular, cast composite materials (LCM) have been developed, which have found application in various friction units operating in severe operating conditions. Currently, the theoretical foundations of the mechanics of reinforced composite materials are well developed, and a significant progress has been achieved in their material science. However, there are still many problems associated with the choice of optimal technology ensuring the achievement in practice of the predicted composites properties by theory, control of interfacial interaction to improve the stability of the structure and properties of CM, with the development of new types of reinforcing elements that can raise the level of composite performance.In the present work results of scientific and experimental studies on the development of casting technology (solid-liquid synthesis) for obtaining composite materials with macroheterogeneous structure have been summarized. The structures of composites are studied for different methods of synthesis, as well as for different chemical composition of cast iron granules. The prospects of using white vanadium cast iron granules as a reinforcing phase are shown.
The quality of semi-finished steel
Authors: Anisovich A. G. 
Published: April 2019

The article deals with the quality of structural steel supplied by metallurgical enterprises. It is shown that the pipes made of steel 20, used in the oil and gas industry, contain structurally free cementite in the structure, often in the form of a grid (points 4 and 5 according to GOST 5640–68). This structure is the cause of faulty production: the subsequent cold treatment pressure formed sags on the surface of the product, and there is a violation of the continuity of the material up to the formation of through cracks. Formation of structurally-free cementite in steel 40KHN2MA with structure of the top bainite which was formed at violation of regulations of heat treatment of a semi-finished product is also found. When nitriding with heating to 490 ° C and holding at this temperature, there was a decay of bainite with the formation of tertiary cementite along the grain boundaries. Discussed the possibility of culling the poor quality of delivery at the consumer. It is also noted that many enterprises have now abolished entrance control, which has the most negative consequences both in terms of product quality and safety, especially in the oil and gas industry.
The dependence of the adhesive properties of the steel cord from the different test methods and application of various compounds
Authors: Khrol O. N. 
Published: April 2019

One of the most important indicators of the quality of the metal cord is the strength of its adhesion to the compound, i.e. adhesive strength. This is due to the fact that the value of adhesive strength significantly affects the performance of tires.The article analyzes how the use of different test methods could determine the adhesive strength and the use of compounds of different consumers affect the amount of adhesion of the metal cord. Three methods of testing of different consumers are considered and compared, the features of each method are revealed. Tests were carried out using different methods and compounds of different consumers; the factors affecting the value of adhesive strength were determined.
Er,Yb:Ca3RE2(BO3)4 (RE=Y, Gd) – Novel 1.5 μm Laser Crystals
Authors: Gorbachenya K. N. , Deineka R. V. , Kisel V. E. , Yasukevich A. S. , Shekhovtsov A. N. , Kosmyna M. V. , Kuleshov N. V. 
Published: April 2019

The search for new crystalline host materials for the usage in lasers emitting in the eye-safe spectral range of 1.5–1.6 µm is an important task. The aim of this work was to study the growth technique, spectroscopic properties and laser characteristics of new active media – crystals Er3+,Yb3+:Ca2RE2(BO3)4(RE=Y, Gd).Calcium-yttrium Er3+,Yb3+:Ca3Y2(BO3)4(CYB) and calcium-gadolinium Er3+,Yb3+: Ca2Gd2(BO3)4 (CGB) oxoborate crystals co-doped with erbium and ytterbium ions were investigated. Polarized absorption and emission cross-section spectra were determined. The lifetimes of4I11/2and4I13/2energy levels of Er3+ions were measured and ytterbium-erbium energy transfer efficiencies were estimated. The calculation of the gain cross-section spectra was performed. By using of Er3+,Yb3+: Ca2RE2(BO3)4 (RE=Y, Gd) crystals the laser performance was realized, for the first time to the best of our knowledge. The laser characteristics were studied in a quasi-CW (QCW) laser operation.The wide band with a peak at the wavelength of 976 nm is observed in the absorption spectra of both crystals. This peak coincides with the emission wavelength of the pump laser diodes for Yb-doped active media. The maximum value of absorption cross-section was 1.7 × 10–20cm2for polarizationE//bfor both crystals. The lifetimes of the upper laser level4I13/2of Er3+ions were 580 ± 30 μs and 550 ± 30 μs for Er,Yb:CYB and Er,Yb:CGB crystals, respectively. The energy transfer efficiencies from ytterbium to erbium ions for an Er,Yb:CYB and Er,Yb:CGB crystals were 94 % and 96 %, respectively. According to gain spectrum of the Er,Yb:CYB crystal the gain band peak is centered at the wavelength of 1530 nm. The maximum QCW output power was 0.5 W with slope efficiency of 13 % regarding to absorbed pump power for an Er,Yb: CYB crystal. The laser beam parameter M2did not exceed < 1.5.Based on the obtained results, it can be concluded that these crystals are promising active media for lasers emitting in the spectral range of 1.5–1.6 μm for the usage in laser rangefinder and laser-induced breakdown spectroscopy systems, and LIDARs.
Device and Methods for Measuring of Acoustic Anisotropy and the Residual Stress in the Main Gas Pipelines’ Metal
Authors: Volkova L. V. , Murav’eva O. V. , Murav’ev V. V. , Buldakova I. V. 
Published: April 2019

One of the main conditions of safe operation of gas pipelines is the use of non-destructive diagnostic methods. Particularly important problem is the earlier operational diagnosis of pipes’ material of main gas pipelines based on the evaluation of the stress-strain state, elastic moduli and properties anisotropy by acoustic methods. The aim of the work is to develop methods for acoustic assessment of the stress-strain state, the elastic moduli and the properties anisotropy of pipeline material and to study these characteristics in different sections of main pipelines using a device based on contactlessEMAtransducers.Methods are implemented using specialized equipment (the structurescopeSEMA) and non-contact electromagnetic acoustic transducers. As an object of research, we used fragments – the cuttings of gas pipelines with circumferential welds both after fabrication and removed from service with stress corrosion cracking, including ones with corrosion damage and without visible damage.The method of determining the plane stress-strain state of pipeline elements is based on the phenomenon of acoustoelasticity – the dependence of the propagation velocity of ultrasonic waves on mechanical stresses. The method for determining the elastic characteristics of materials and the anisotropy of their properties is based on the relationship between the velocities of ultrasonic waves and the elastic properties of the medium. Both techniques are implemented by sounding the sample in one section using a longitudinal wave and two shear waves with mutually perpendicular polarization planes coinciding with the main stresses, and measuring their propagation times.It is shown that the stress state distribution both in the circumferential direction and along the generatrix is uneven which is caused by the peculiarities of samples (presence of a welded joint, stress corrosion cracking, long-term operation). The smallest acoustic anisotropy is observed for the Young's modulus. The anisotropy of the properties of most samples is in the range of 12–14 % for shear modulus, 9–10 % for Young’s modulus, 13–15 % for Poisson’s ratio. For samples with stress corrosion cracking a sharp decrease in the anisotropy coefficient is observed which makes it possible to use the indicated characteristics as informative parameters in detecting stress corrosion cracking.A feature of the proposed methods is high accuracy, due to the absence of necessity to determine the material density and precision measurement of its thickness, the measurement error of which is significant by known methods.Keywords:main gas pipeline, elastic moduli, acoustic anisotropy of properties, the biaxial stress-strain state, longitudinal and transversal waves.
Modeling of an Impact of Thin Insulating Film on the Electrode Surface on Discharge Ignition in Mercury Illuminating Lamps at Low Ambient Temperatures
Authors: Bondarenko G. G. , Fisher M. R. , Kristya V. I. , Żukowski P. 
Published: April 2019

The mixture of argon and mercury vapor with temperature-dependent composition is used as the background gas in different types of gas discharge illuminating lamps. The aim of this work was to develop a model of the low-current discharge in an argon-mercury mixture at presence of a thin insulating film on the cathode and to investigate the influence of film on the discharge ignition voltage at low ambient temperatures. When discharge modeling, we used the obtained earlier expression which describes dependence of the mixture ionization coefficient on temperature. When there was a thin insulating film on the cathode the model took into account that positive charges are accumulated on its surface during the discharge. They generate an electric field in the film sufficient for the field emission of electrons from the metal substrate of the electrode into the insulator and some of them can overcome the potential barrier at the film outer boundary and go out in the discharge volume improving emission characteristics of the cathode.Calculations showed that at a temperature decrease the electric field strengthes in the discharge gap and the voltage in it are increased due to reduction of the saturated mercury vapor density in the mixture followed by the decrease of its ionization coefficient. Existence of a thin insulating film on the cathode surface results in an increase of the cathode effective secondary electron emission yield which compensates the reduction of the mixture ionization coefficient value.The results of discharge characteristics modeling demonstrate that in case of the cathode with an insulating film the discharge ignition becomes possible at a lower inter-electrode voltage. This ensures outdoor mercury lamp turning on at a reduced supply voltage and increases its reliability under low ambient temperatures.
About a concept of creating a social network users information aggregation and data processing system
Authors: Rudikova L. V. , Myslivec O. R. 
Published: April 2019

The development of a general concept and implementation of a data-storage and analysis system for practice oriented data, one of the subsystems of which is an analytical system for the accumulation and analysis of data from users of social networks, is topical. The development of a general concept and implementation of a data-storage and analysis system for practice oriented data, one of the subsystems of which is an analytical system for the accumulation and analysis of data from users of social networks, is topical. Data that users leave about themselves in social networks can be useful in solving various tasks. The proposed article describes the subject area associated with the collection and storage of data from users of social networks. Proceeding from the subject area, the general architecture of the universal data collection and storage system is proposed, which is based on the client-server architecture. For the server side of the system, a fragment of the data model is provided, which is associated with the accumulation of data from external sources. The framework of the system architecture is described. The developed universal system is based on the information technology of data warehousing, and it has the following aspects: an expandable complex subject area, the integration of stored data that come from various sources, the invariance of stored data in time with mandatory labels, relatively high data stability, the search for necessary trade-off in data redundancy, modularity of individual system units, fl and extensibility of the architecture, high security requirements vulnerable data.The proposed system organizes the process of collecting data and filling the database from external sources. To do this, the system has a module for collecting and converting information from third-party Internet sources and sending them to the database. The system is intended for various users interested in analyzing data of users of social networks.
Features of training 3d computer modeling and visualization of future teachers of informatics
Authors: Rylova O. G. 
Published: April 2019

The cognitive, developing, illustrative potential of three-dimensional computer graphics actualizes the training of future teachers in its technologies. The future teacher of computer science should be able to develop three-dimensional models and animations of the studied objects (phenomena and processes) in computer science, physics, mathematics and other academic disciplines, create copyright electronic educational resources with three-dimensional illustrations, apply augmented reality and 3D printing in professional activities.The article describes the features of teaching three-dimensional computer modeling and visualization of future informatics teachers, identified on the basis of an analysis of the training system for students studying in specialty 1–02 05 02 Physics and Informatics at the Maxim Tank Belarusian State Pedagogical University.The main directions for improving the learning process of three-dimensional computer graphics of future informatics teachers are indicated. Questions on three-dimensional computer modeling and visualization will pass through the content line through the content of six academic disciplines («Computer graphics and multimedia», «Computational methods and computer modeling», «Programming Technologies and Algorithmization Methods», «Information Technologies in Education», «Methods teaching informatics» and «Architecture and software of computer systems»). This will ensure consistency in the introduction and study of concepts, the choice of forms and methods of teaching, the development of teaching and methodical support. For the implementation of interdisciplinarity, it is proposed to carry out practice-oriented interdisciplinary educational projects in the framework of the study of academic disciplines in three subject areas «Computer Science», «Physics» and «Mathematics». The development of a methodical system of interdisciplinary education will ensure the formation of readiness to teach three-dimensional graphics at the stage of general secondary education and to realize its didactic possibilities in organizing educational and research activities of students.
An analysis of public sector spending on education in Pakistan and its impact on the productivity and employability of Pakistan’s human resource
Authors: Aslam Qais 
Published: April 2019

This paper reviews the budgetary expenditures on public sector education in Pakistan, its issues and impact on sectorial jab creation as percentage of GDP. It shows that there are multiple education systems in Pakistan with different medium of instruction and gender segregation at school levels and with multiple problems and inefficiencies. In addition, there are inadequate schools for boys and girls. Budgetary expenditure on Tertiary education is 35% and on school education 65%. There are 185 Universities in the country. The share of Agriculture in GDP in 2012-2018 period declined by 2.5%, of Industry declined by 6.7%, whereas the share of services sector grew by 9.2% increasing job opportunities in the new knowledge based economy at the cost of manufacturing sector.
Government should built more schools at all levels with modern facilities and infrastructures even at remotest corners of the country. There should be scientific upgradation of teachers at all levels. Textbooks should encourage research based gender sensitive, environment sensitive and productivity orientated scientific and technological knowledge with a more progressive worldview in order to create greater linkages between school system and Higher Education with emphasis on the knowledge economy of tomorrow that incorporates international labor and human rights standards.