scholarly journals CHANGE IN THE TENSILE STRENGTH OF PRESSED BIRCH WOOD DURING LOCAL CRUSHING

Author(s):  
Svetlana Snegireva ◽  
Anna Kurnikova

At present, due to the reduction of business wood stocks, the problem of using fast-growing soft hardwoods as industrial raw materials is of particular relevance. This wood has a number of disadvantages – low density, low strength indicators, which limit the scope of its application. It is possible to improve the quality of soft hardwood wood by pressing it (compacting). Compaction of wood has a great influence on the physical and mechanical properties of wood. The wide application of pressed wood is possible in the production of railway sleepers. Pressing wood significantly increases the performance properties of the sleeper beam. One of the advantages of wooden railway sleepers is their high damping properties. The presence of damping properties in wooden sleepers ensures high speed performance and a long service life of the rolling stock. In this connection, research that ensures the rational use of wood raw materials is relevant. The purpose of this study is to determine the nature of the change in the strength limit of pressed birch wood (Betula pendula) during local crumpling.

1975 ◽  
Author(s):  
M. R. Garde

This paper presents a discussion on aircraft type gas-turbine train development. For railway traction purposes, the turbo-engines used on aircraft would improve the quality of the services provided in the electrified lines. The gas turbine should insure high speed and satisfactory acceleration. It would enable relatively lightweight construction to be carried out and run at a higher speed than trains on non-electrified lines. The gas turbine will not completely replace the diesel engine, but it will enable rolling stock to be constructed for which the diesel is unsuitable, especially in the case of high-speed, lightweight trainsets and, in the future, very high-powered units.


2018 ◽  
Vol 180 ◽  
pp. 06007
Author(s):  
Jan Raczyński

Choosing a high-speed rail vehicle depends on many factors. On the one hand, there are requirements for ensuring the quality of service for passengers, on the other hand, there are constraints resulting from the parameters of available infrastructure. Also a relation of the benefit and financial costs associated with the purchase and the operation of rolling stock is essential. Technical characteristics of vehicles selected for operating a particular system is a compromise between the three groups of requirements. In this article technical parameters of railway infrastructure and rolling stock are classified and then analysed from the TSI requirements point of view.


10.5219/1434 ◽  
2020 ◽  
Vol 14 ◽  
pp. 862-873
Author(s):  
Mykola Nikolaienko ◽  
Larysa Bal-Prylypko

The high-speed growth in the global population has resulted in a deficit of foods, which has stimulated the development of technologies for planting agricultural products and fattening domestic animals. However, these processes are supplemented in many cases by worsening of the quality of foods and their pollution by foreign substances. To guarantee the proper quality and safety of foodstuffs for health, the International Organization for Standardization developed the standards ISO 9001:2015 and ISO 22000:2018. At the same time, businesses fabricating foods, especially meat-based ones, have to observe the norms of the international standard ISO 14001:2015. Finally, because treatments of raw materials and ingredients used in food products contain in many cases substances harmful for health, enterprises must introduce the norms of standard ISO 45001:2018. To simplify management processes, enterprises introduce so-called ‘integrated management systems’. This study proposes one variant of such a system recommended for use in food-producing organizations including those that treat raw meat and produce products based on its use.


2020 ◽  
Vol 5 (86) ◽  
pp. 3-10
Author(s):  
V.G. Chernikov ◽  
◽  
R.A. Rostovtsev ◽  
N.A. Kudryavtsev ◽  
I.V. Uschapovsky ◽  
...  

The formation of fiber flax yield and quality parameters depends on many soil-climatic, breedinggenetic, as well as anthropogenic factors. The quality of flax fiber is a combination of a number of features and properties that depend on the varietal characteristics of plants, the conditions of their cultivation, technologies for harvesting and straw retting, as well as on the processing modes of raw materials. During plant vegetation (90-130 days) many factors such as soil conditions (pH 4.8-5.5, humus 1.8-2.5%, P2O5 and K2O – 150-200 and 100-200 mg/kg, respectively) and the area of plant nutrition (15-30 million seeds/ha), temperature regime (the sum of active temperatures 1000-1800ºC), water supplying (400-430 units of water mass to create 1 unit of dry matter) and insolation (the arrival of FAR during the growing season 20-25 kcal / cm²), contamination of weeds (more than 60 annual and perennial species) and pests (more than 200 types of fungal, bacterial and viral diseases), features of phytosanitary measures (more than 50 chemicals) and agrotechnologic manners (Federal Register of technologies for the production of crop products) have a great influence on the quality of flax raw materials and can be a limit factor. Environmentally hazardous pollution of air, water and soil - the main components for the production of fiber flax – strongly affects the yield and quality of flax products. The development of waste-free environmentally friendly technologies for the cultivation, harvesting and processing of flax is an urgent task of scientific support of the industry. The main environmental factors affecting the yield and quality of fiber flax are discussed in the article.


Author(s):  
Shih-Chun Wang ◽  
Kuang-Yuh Huang

In order to improve the machining efficiency of ultra-precision and micro fabrication technology, a high speed spindle is essential for the minitype tools widely applied in systems such as PCB drilling machines, micro fabrication machines, dental handpieces, etc. To realize the high speed performance, the air driven turbine is verified to be more feasible than the electromagnetic actuator. Furthermore, the operational efficiency and quality of the high speed spindle are significantly influenced by the turbine blades and the bearings respectively. Through detailed configurational studies and performance analyses on diverse minitype turbine blades, we have derived the efficiency- and quality-influential parameters. And based on optimization results, we have developed a novel type of twin bladed air turbine (TB-air turbine), which consists of two parallel blades with an angular offset. The offseted twin blades can efficiently and smoothly transform pneumatic energy into rotational energy. Therefore, steady driving force and less dynamic unbalance are able to be easily achieved for reducing nervous disturbances such as vibration, noise, and wear. By applying finite element analytical method, the operational performances and quality of the new developed twin bladed air turbine such as rotational speed, torque, vibration and noise were analyzed for comprehending influences of the design parameters and the operational parameters. While the inlet angle, the blade shape and its geometric parameters are the dominant design parameters; the inlet pressure and mass flow rate, and the outlet pressure are the main operational parameters. Through the turbine blades, the pneumatic energy will be transformed into operational energy in form of the flow field and the pressure distribution and the energy loss in form of turbulence. Also by integrating knowledge of production technology, a neat design of the turbine blades suitable for automatic manufacturing process is developed. And furthermore, through an elaborate layout of the flow guiding, a minimum rotational runout can be effectively achieved without any complicate and costly dynamic balancing process. Consequently, it has significantly depressed the stream noise and raised the operation lifetime of bearings. According to our experimental verification, the vibration and the stream noise of our TB-air turbines are 60% and 50% lower than traditional counterparts respectively. Our developed minitype spindle with novel TB-air turbine can efficiently realize high speed rotation with high torque, less vibration and less noise.


2018 ◽  
Vol 931 ◽  
pp. 558-563 ◽  
Author(s):  
Viktoriya A. Guryeva ◽  
Viktor V. Dubineckij ◽  
Aleksandr V. Doroshin

Investigations of the influence of dispersion of feedstock on the basis of clay of the Buguruslan deposit and drill cuttings from the facilities of PJSC «Orenburgneft» have been carried out, it is revealed that as the grinding time increases, the content of clay and dust particles increases. Intensive sintering of the samples between 1000 °C and 1100 °C has been established, which is confirmed by the compaction of the samples and the decrease in the water absorption of the ceramic masses. Minimal water absorption, within 2.35%, showed a sample of 3-hour grinding, and a sample of a 2-hour grinding of 8.34%. As a result of the study of dispersion of the charge on the basis of clay raw materials and drill cuttings, it was found that by subjecting the original composition to additional processing, within 2 hours, the physical and mechanical properties of ceramic bricks can be improved.


2021 ◽  
pp. 71-75
Author(s):  
Н.П. Тишанинов ◽  
А.В. Анашкин ◽  
К.Н. Тишанинов ◽  
Х.Д.Д. Альшинайиин

Представлены результаты исследований физико-механических свойств компонентов зерносмеси, динамики и качества выделения примеси из неё в зависимости от скоростного режима работы триера (n) и угла подъёма верхней кромки передней стенки выводного лотка (γn). Подтверждён лавинообразный характер выделения проса из ячменя в первых интервалах времени измерений за счёт эффекта динамической сегрегации примеси в циркулирующих слоях зерносмеси. Положительный вектор сегрегации проса (вниз – к ячеистой поверхности) объясняется значительной его насыпной плотностью, гладкой поверхностью – угол естественного откоса составляет 20,3° (в 1,8 раза меньше, чем у ячменя), компактными размерами зерновок и их округлой формой. Установлена высокая степень влияния на интенсивность выделения примеси скоростного режима – при приросте n на 12,5% (от 40 до 45 об/мин) выделенная масса примеси в первом интервале времени измерений (tи = 5 с) увеличилась на 125%. При γn= 35° степень выделения примеси (и остаточная засорённость) обеспечиваются на высоком уровне стандартной длиной ячеистого цилиндра (l = 2,2 м) во всём диапазоне скоростного режима работы стенда n = 40…55 об/мин. С ростом γn до 45º сужается диапазон скоростного режима работы по качественным показателям до n = 45…55 об/мин, а при γn= 55º качество работы обеспечивается только при n = 50…55 об/мин. При γn= 45…50º и n = 50…55 об/мин 100%-ное выделение примеси обеспечивается за 30…35 с смещения сегмента зерносмеси по длине ячеистого цилиндра. При этом его рабочая длина используется лишь на 55…64%. Технологические потери на всех исследуемых режимах работы не превышают 0,3% и носят случайный характер, что объясняется неопределённостью условий выброса зерновок ячменя ячеями. The research results of physical and mechanical properties of grain mixture components, dynamics and quality of impurity extraction from it are presented depending on the speed mode of operation of the trieur (n) and the lifting angle of the upper edge of the front wall of the lead tray (γn). Avalanche-like character of millet separation from barley in the first intervals of measurement time is confirmed due to effect of dynamic segregation of impurity in circulating layers of grain mixture. The positive vector of millet segregation (down to the cellular surface) is explained by its significant poured density, a smooth surface – the angle of friction is 20.3° (1.8 times less than that of barley), compact bruchid sizes and their rounded shape. A high degree of influence on the rate mode impurity release intensity was established – at an increase of n by 12.5% (from 40 to 45 rpm), the extracted impurity mass in the first measurement time interval (tи = 5 s) increased by 125%. At γn = 35°, the degree of impurity release (and residual content of impurities) is provided at a high level by the standard length of the cellular cylinder (l = 2.2 m) in the entire range of the speed mode of the bench n = 40...55 rpm. With an increase in γn to 45º the range of the high-speed mode of operation is narrowed to n = 45...55 rpm, and at γn = 55º the quality of operation is ensured only at n = 50...55 rpm. At γn = 45...50° and n = 50...55 rpm 100% impurity release is ensured by 30...35 second with displacement of the grain mixture segment along the length of the cellular cylinder. At the same time, its working length is used only on 55...64%. Technological losses in all investigated modes of operation do not exceed 0.3% and are random in nature, which is explained by the uncertainty of the conditions for the release of barley bruchids by cells.


2021 ◽  
Vol 9 (2) ◽  
pp. 207
Author(s):  
Asmawati Wurya Sari ◽  
M Dirhamsyah ◽  
Yuliati Indrayani

This research aimed to analyze the physical and mechanical properties of particleboard based on the composition of raw materials and adhesive content as well as their interaction with the optimum quality of particle boards that meet JIS A 5908-2003 standards. The particleboard was made with a size of 30 cm x 30 cm x 1 cm with a target density of 0.7 g/cm³.  The pressing was done at a temperature of 140°C for 8 minutes with a pressure of 25 kg/cm². The composition ratio of betel nut peel waste and sawdust varied, namely 60% betel nut peel waste: 40% sawdust, 50% betel nut peel waste: 50% sawdust, and 40% betel nut peel waste: sawdust 60%. The adhesive used was Urea Formaldehyde with a concentration of 12%, 14%, and 16%. The results showed that all test values met the JIS A 5908: 2003 standard except the MOE test. The optimum value of particle board of betel nut peel and sawdust was with a composition ratio of 50% betel nut peel waste: 50% sawdust, 16% adhesive content, with a density value of 0.6876 g/cm³, a moisture content of 9,4530%, water absorption 34,5306%, thickness expansion 8,2508%, MOE 12432,6243 kg/cm², MOR 205,8462 kg/cm², adhesive firmness 2,2530 kg/cm², screw holding strength 81,6861 kg/cm².Keywords: adhesive content, betel nut peel waste, material composition, mechanical properties, particleboard, physical.Abstrak Penelitian ini bertujuan untuk menganalisis sifat fisik dan mekanik papan partikel berdasarkan komposisi bahan baku dan kadar perekat serta interaksi keduanya terhadap kualitas papan partikel yang optimum serta memenuhi standar JIS A 5908-2003. Papan partikel dibuat dengan ukuran 30 cm x 30 cm x 1 cm dengan target kerapatan 0,7 g/cm³. Pengepresan  pada suhu 140°C selama 8 menit dengan tekanan 25 kg/cm². Perbandingan komposisi kulit buah pinang dan serbuk kayu gergaji bervariasi yaitu kulit buah pinang 60% : serbuk kayu gergaji 40%, kulit buah pinang 50% : serbuk kayu gergaji 50% dan kulit buah pinang 40% : serbuk kayu gergaji 60%. Perekat yang digunakan adalah Urea Formaldehida dengan konsentrasi 12%, 14% dan 16%. Hasil penelitian menunjukkan semua nilai uji memenuhi standar JIS A 5908 : 2003 kecuali uji MOE. Nilai papan partikel kulit buah pinang dan serbuk kayu gergaji optimum dengan perbandingan komposisi kulit buah pinang 50% : serbuk kayu gergaji 50%, kadar perekat 16%, dengan nilai densitas 0,6876 g/cm³, kadar air 9,4530%, daya serap air 34,5306%, pengembangan tebal 8,2508%, MOE 12432,6243 kg/cm², MOR 205,8462 kg/cm², Keteguhan rekat 2,2530 kg/cm², kekuatan menahan sekrup 81,6861 kg/cm².Kata kunci : papan partikel, kadar perekat, kulit buah pinang, komposisi bahan, sifat fisik dan mekanik.


Author(s):  
Ilyas Ichsan

Research on the use of limboto lake sludge as raw material for bricks by adding sand as a mixture of materials using experimental quantitative research. In the study used limboto lake silt with sand mixture with variations of2%, 5%, 7%, 10% and 15%. Related variables are physical and mechanical properties of bricks. The controlling variable is the materials used.The results showed that bricks with raw material from limboto lake sludge with a mixture of sand with variations of 2%,5%, 7%, 10% and 15% did not produce the right composition to have the same quality of bricks with bricks using raw materials clay. Penelitian pemanfaatan endapan lumpur danau limboto sebagai bahan baku batu bata dengan penambahan pasir sebagai bahan campurnya menggunakan penalitian kuantitatif yang bersifat eksperimen. Dalam penelitian digunakan bahan endapan lumpur danau limboto dengan campuran pasir dengan variasi 2%, 5%, 7%, 10% dan 15%. Variabel terkait berupa sifat fisik dan mekanik batu  bata. Variabel pengendali adalah bahan-bahan yang digunakan. Hasil penelitian menunjukan bahwa batu bata dengan bahan baku endapan lumpur danau limboto dengan campuran pasir dengan variasi 2%, 5%, 7% 10% dan 15% tidak  menghasilkan komposisi yang tepat untuk memiliki kualitas batu bata yang sama dengan batu bata yang menggunakan bahan baku tanah liat.


2021 ◽  
Author(s):  
Douglas Lamounier Faria ◽  
Jane Cecília Oliveira Guimarães ◽  
Thiago de Paula Protásio ◽  
Lourival Marin Mendes ◽  
José Benedito Guimarães Junior

Abstract The use of alternative raw materials to produce particleboards is an interesting strategy to add value to lignocellulosic biomass and diversify the forest products industry. The aim of this study was to evaluate the potential for using Mauritia flexuosa particles in association with Eucalyptus spp. wood for the production of particleboards. Prior to the production of the panels, the raw materials were evaluated for basic density and chemical composition. The panels were produced with particles of Eucalyptus spp. and Mauritia flexuosa in mass proportions of 100/0%, 90/10%, 80/20%, 70/30% and 60/40%, respectively. The quality of the particleboards was evaluated by water absorption and thickness swelling, internal bonding and static bending tests. As Eucalyptus spp. particles were replaced by Mauritia flexuosa, the panels showed less dimensional stability, due to the fact that the compression ratio increased due to the lower density of Mauritia flexuosa particles. The substitution of 1% of Mauritia flexuosa particles caused a reduction of 10.49 MPa for MOE, 0.09 MPa for MOR and 0.01 MPa for internal bonding. The results demonstrate that it is feasible to replace up to 17.5% of Eucalyptus spp. wood with particles from Mauritia flexuosa so that the panels have physical and mechanical properties appropriate to the marketing standards.


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