Добірка наукової літератури з теми "Physical-mechanical indicators"

The article examines and analyzes the physical and mechanical properties of different proportions of jeans and knitted fabrics recommended for children's combined outerwear. It also offers the most alternative fabric patterns for children's outerwear.

The influence of the graphite concentration on the main physical-mechanical properties of nanocomposites based on such polyolefin as high density polyethylene, low density polyethylene and polypropylene is considered. Properties such as tensile yield stress, ultimate tensile stress, and ultimate bending strength, elongation at break, heat resistance, flexural strength, MFI, and melting points are analysed. To improve the compatibility of the mixed components of the mixture, we used an Exxelor PO1040 compatibilizer for all grades of polyethylene and Exxelor PO1020 for polypropylene. Graphite was introduced into the composition of polyolefin at the following concentrations: 1.0, 3.0, 5.0, 10, 15, 20, and 30 wt%. As a result of the research, it was found that the introduction of graphite into the composition of polyolefin was accompanied by an improvement in strength characteristics with maximum at various concentrations. For high density polyethylene, the maximum values of strength characteristics are observed at 3.0 wt%, for low density polyethylene at 10 wt%, and for polypropylene at 5.0 wt% content of graphite. It revealed that such a difference in the value of the threshold concentration of graphite which provides the maximum value of strength indicators,was directly related to the degree of crystallinity of the polymer matrix.

Studies that are presented in this paper were carried out to define the formation criteria of loess soil degradation. Erosion stability analysis of this soil type will be carried out on the basis of its physical and mechanical characteristics. To describe the established relationships between the individual parameters of loess soil, the study uses mathematical model, that is based on experimentally obtained results of soils? physical and mechanical characteristics, From the presented results of geotechnical tests, mathematical models and functional relations between water regime and loess soils? resistant characteristics; indicators of internal erosion were defined as well as the mechanism of this process. Effects of the practical application of found results are also analyzed in this paper.

Pelleted fertiliser production represents improvements in fertiliser management and ensures several benefits, such as a more accurate dosing (less applications), the slow-release of long-lasting nutrients, the possible application during the whole year, easier storage and transportation and better separation of fertilisers and pesticides. The present research investigated the physical-mechanical properties of a pelleted chicken litter organic fertiliser. The pellet samples' particle density ρ (kg·m^–3), mechanical durability DU (%), compressive strengths in the cleft σc (N·mm^–1) and in simple pressure σp (MPa) were investigated. The last two indicators, σc and σp, demonstrated the pellets' resistance to the compressive stress. The resulting values proved ρ = 1 289.73 kg·m^–3, DU = 95.5%, σc = 58.61 N·mm^–1 and σp = 20.02 MPa, while all the results were evaluated positively. The observed level of the DU (%) did not achieve the mandatory level for the commercial production of pellets (DU = 97.5%), however, such a level is stated for a pellet solid biofuel intended for energy production. Therefore, the achieved level of the DU (%) represents a satisfactory result within the investigated pellet samples' mechanical quality. In general, the viability and practicability of chicken litter pellet production was proven, as well as, the suitability of such a feedstock for pellet production. Moreover, the observed results proved a high level of the investigated pellet samples' mechanical quality.

The purpose of the study was to carry out a comparative analysis of self-etching self-adhesive double-fixation cements for indirect restorations in terms of physical and mechanical properties. Materials and methods. For comparison, in terms of physical and mechanical parameters, a self-etching self-adhesive composite cement for indirect restorations "Maxcem Elite", Kerr, California, USA was taken. "Maxcem Elite" refers to self-etching self-adhesive composite cements of double fixation, which has a number of positive qualities, such as high physical and mechanical properties, good aesthetic properties, radiopacity. We analyzed the following physical and mechanical parameters: the appearance of the paste, depth of hardening, mm, diametric strength, MPa, conical yield point according to Heppler, MPa, hardness according to Heppler, MPa, water absorption in 7 days, μg/mm3, water solubility in 7 days μg/mm3, adhesive strength, MPa, peel strength, MPa. Results and discussion. According to the average test depth of hardening (mm) material "Maxcem Elite" is inferior to others: material Bifix QV by 14.9% and Relyx U 100 by 13.3%. This does not significantly affect the quality of the connection of the adhesive structure with the hard tissues of the tooth, especially due to the method we have developed for the preparation of abutment teeth in the manufacturing of adhesive pads. On the other hand, according to the average value of the index of diametrical strength (MPa), the studied material "Maxcem Elite" is by 17.2% better than Bifix QV, and by 17.3% better than Relyx U 100. Comparing these and other physical and mechanical properties of materials on average, one must bear in mind the random nature of these values. From the results of the study, it can be seen that the difference between the indicators of the Maxcem Elite material and analogues is confirmed at a very high level of significance. The study of the level of water absorption indicates the probable absence of variability of the indicator of the studied material in comparison with comparable analogs. The value of the water solubility index of all the composites under study practically does not differ from the value of "Maxcem Elite" (within (2.5±0.1) %), and corresponds to the requirements of ISO 4046. Conclusion. The research results show that the investigated composite material "Maxcem Elite" in the main parameters corresponds to analogs, in most of the indicators it combines their best characteristics. In it, the adhesive strength of the connection with the hard tissues of the tooth is noticeably enhanced and better peel strength makes it possible to profitably use this material "Maxcem Elite" for fixing the adhesive structures

The research aims to study and analyze the physical-mechanical and technological properties of eroded soils in Uzbekistan. The data on the susceptibility of water erosion to sloping lands is presented. The average monthly indicators of precipitation over the last ten years in Uzbekistan are analyzed. The results of determining the moisture, density, and hardness of the soil of slopes are presented. It has been established that with the traditional technology of tillage on moisture, density, and other technical properties of soil of slopes, water erosion and slope of fields have a significant effect. The physical-mechanical and technological properties of soil of the arable and subsurface layers of the soil of the top, the middle and lower part of the slope in spring and after grain harvesting differs significantly: in the spring period, the moisture of soil layers 0-10; 10-20; 30-40; 40-50 and 50-60 cm of the lower part of the slope is more moisture content of these layers of the top respectively, 1.16; 1.24; 1.1; 1.4; 1.54 and 2.15 times. Approximately such a picture of moisture is preserved after grain harvesting as well.

In this paper fatigue for professional soldier caused by active physical activity and endurance limits is investigated. The resulting workload is one of indicators of how training, preparedness and other acquired work skills can contribute to the human body being a large working “machine”. Ergometry test was conducted and field test for soldier fitness condition and energy expenditure was measured regarding the level of body’s metabolism. Field test consisted of three runs on a polygon of 10 km and different workloads, the energy consumption was monitored. Work load was compared with Occupational Safety and Health law acts. The results showed difference in workload conditions and hart rate which allowed to determine rest spots and safety in training conditions.

This research investigated parameters that can affect the use of nanoporous silica gel as a media for accumulating a detectable amount of uranium. The unique fluorescence of the Uranyl (UO22+) ion was used to evaluate the transport kinetics and accumulation within silica gel in a static fluid and under pressure driven flow. The addition of fluid flow decreased the time constant from on the order of an hour to approximately 2s with a very low fluid velocity of 0.36cm/s. The 0.36cm/s fluid velocity was found to be the critical velocity above which there was no gain in time constant. A table top instrument was developed that can detect trace amounts of uranium in solution. The table top instrument was used to investigate how the time constant depends on the uranyl concentration, which led to the development of a new time-based method for quantifying the uranyl concentration. The time-based method of detection uses a preset threshold and, based on the time it takes to reach that threshold, the concentration in the water sample can be determined. The lifetime of uranyl in complex with silica increased to approximately 120us, allowing for gated detection and background discrimination. In addition to the fluorescent contaminants, competing cations were tested to determine how they affect the fluorescence and transport kinetics of the uranyl. The cations tested were Mn2+, Ca2+, Mg2+, Na+, K+, and Li+. The result shows that within the natural concentrations, Mg2+, Na+, and K+ did quench the fluorescent of the uranyl ions by collision quenching. The time constant was also examined in the presence of each cation and showed that Ca2+, Mg2+, Na+, and K+ decreased the adsorption time constant. Future studies in this area should be directed toward the development of a portable version of the instrument.

Актуальність теми: підвищення рівня якості паперу-основи для рушників та продуктивності технологічного обладнання з виготовлення паперу-основи для рушників на ПрАТ "Київський картонно-паперовий комбінат". Мета і задачі дослідження: розроблення заходів та вирішення ряду задач з метою реконструкції технологічного потоку виробництва паперу-основи для рушників і підвищення якості продукції, що виготовляється. Об’єкт дослідження: технологічний процес виробництва паперу основи для рушників. Предмет дослідження: вихідні волокнисті напівфабрикати, режими роботи обладнання та технологія виготовлення паперу основи для рушників. Методи дослідження: літературний пошук, дослідження технологічних режимів, фізико-механічні методи випробування отриманих зразків в лабораторних умовах фабрики в процесі реконструкції технологічного потоку. Практичне значення одержаних результатів: реконструкція технологічного потоку дає можливість зменшити собівартість і, разом з тим, підвищити якість готової продукції, що виготовляється на ПрАТ Київський картонно-паперовий комбінат. Апробація результатів дисертації: Запропоновано шляхи реконструкції технологічного потоку Приватного акціонерного товариства "Київський картонно-паперовий комбінат" з виробництва паперу основи для рушників. Основні етапи реконструкції, викладені в дисертаційній роботі, знайшли відображення в тезах конференцій та статті: - Комісаренко Р.В., Плосконос В.Г. "Підвищення рентабельності і економія енергії у виробництві санітарно-гігієнічних видів паперу"\\Зб.тез доповідей XXIII Всеукраїнської наук.-практ.конф. студ.,аспір. і молодих вчених “Обладнання хімічних виробництв і підприємств будівельних матеріалів”, К.: 2018 ,28-29.11,с.68-69. - Плосконос В.Г., Комісаренко Р.В., Котлярська Н.О., Якименко О.С. Використання свіжої води в процесах виробництва целюлозно-паперової продукції та необхідність скорочення її споживання //Міжнародний науковометричний журнал "Інтернаука". - 2018. - №17(57),т.1, с.61-64. Публікації: за темою дисертації опубліковано статтю в науковометричному журналі "Інтернаука" та 2 тези доповідей на міжнародних та республіканських конференціях.
Relevance of the theme: raising the level of quality of the paper-base for towels and productivity of technological equipment for the production of paper-base for towels at PJSC "Kyiv Cardboard and Paper Mill". Purpose and objectives of the study: development of measures and solving a number of problems with a view to reconstructing the technological flow of production of paper-based for towels and improving the quality of manufactured products. Object of research: technological process of paper production basis Object of research: the technological process of producing paper bases for towels. Subject of research: output fibrous semi-finished products, operating modes of equipment and technology for producing paper bases for towels. Methods of research: literary search, research of technological regimes, physical and mechanical methods of testing the samples obtained in laboratory conditions of the factory in the process of reconstruction of the technological flow. The practical value of the results: the reconstruction of the technological flow makes it possible to reduce the cost and, at the same time, improve the quality of finished products, produced at PrAT Kyiv Cardboard and Paper Mill Testing the results of the dissertation: the ways of reconstruction of the technological flow of the Private Joint-Stock Company "Kiev Cardboard and Paper Mill" for the production of paper for the basis for towels are proposed. The main stages of the reconstruction, presented in the dissertation, were reflected in the theses of conferences and articles: - Komisarenko RV, Ploskonos VG "Increasing profitability and saving energy in the production of sanitary-hygienic types of paper" \\ Zb.tez reports XXIII All-Ukrainian Sciences. Prakt.konf. studio, aspiration and young scientists "Equipment of chemical manufactures and enterprises of building materials", K .: 2018, 28-29.11, p.68-69. - Ploskonos VG, Komisarenko RV, Kotlyarskaya N.O., Yakimenko O.S. Use of fresh water in the processes of production of pulp and paper products and the need to reduce its consumption // International scientific and mathematical journal "Interna-nauka". - 2018. - № 17 (57), t.1, p.61-64. Publications: on the topic of the dissertation an article was published in the scientific-science journal "Internet Science" and 2 theses of reports at international and republican conferences.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
No-tillage (NT) is a tillage system more important for the sustainability of agro-ecosystems. However doubts remain concerning the formation of layers with high compaction level in NT, residual effects of soil chiseling, and alteration of soil structure during the time of adoption of NT. The objective of this study was to evaluate the effect of crop rotation, chiseling and periodic time of adoption of NT on the physical quality of a Rhodic Eutrudox, and productivity of soybean and wheat. The tillage systems were: (i) conventional tillage by disk harrow (CT); (ii) NT with chiseling every year (NTC1); (iii) NT with chiseling every three years (NTC3); (iv) NT for 11 consecutive years (NT11) and; (v) NT for consecutive 24 years (NT24) while the cropping factor include: (i) crop rotation and (ii) crop succession. Sampling was conducted 10 and 22 months after last chiseling in NTC1 and NTC3, respectively. Undisturbed soil samples were collected in soil layers, 0.0-0.10, 0.10-0.20 and 0.20-0.30 m for the determination of physical attributes (particle density and particle size distribution, bulk density, porosity, macro and micropores, soil penetration resistance (SPR), SPR curve, water retention curve, least limiting water range), while disturbed samples were used to quantify soil chemical properties (soil acidity, macronutrients, organic carbon, nitrogen). In the soil depth, 0.10 and 0.20 m, three-dimensional infiltration rate and saturated hydraulic conductivity were determined in-situ. At maturity, the productivity of soybeans and wheat was determined. There was no interaction between tillage and cropping system. The variables analyzed did not change as a function of the cropping systems. The chemical attributes were not limiting the productivity of soybeans. The physical attributes indicated that the residual effects of soil chiseling did not persist for longer than 10 months. Increasing the time of adoption of NT from 11 to 24 years favored improvements in soil physical quality. The NT24 had higher yield of soybeans than SPC. Chiseling did not result in increased productivity of soybeans and wheat compared with NT. The increased time without tilling the soil, in the same soil bulk density and water content favored increase in resistance of soil structure. Critical limits of SPR (2 MPa) are inadequate for the assessment of soil physical quality in NT with or without soil chiseling. These SPR limits should be expanded to 3 MPa in NT with chiseling and 3.5 MPa in NT. The least limiting water range, regardless of soil management, cropping system and critical limits of SPR was not a good indicator of soil physical quality.
O sistema plantio direto (SPD) é o sistema de manejo mais importante para a sustentabilidade dos agroecossitemas. No entanto persistem dúvidas relacionadas com a formação de camadas com maior nível de compactação em SPD, efeitos residuais da escarificação do solo, e alteração da estrutura pelo tempo de adoção do SPD. O objetivo deste trabalho foi avaliar o efeito da rotação de culturas, da escarificação periódica e do tempo de adoção do SPD na qualidade física de um Latossolo Vermelho Distroférrico, e na produtividade de grãos de soja e do trigo. O delineamento experimental foi de blocos ao acaso, em esquema fatorial 5x2 (manejos do solo x modelos de produção), com quatro repetições. Os sistemas de manejo do solo foram: (i) sistema de preparo convencional (SPC); (ii) SPD escarificado a cada ano (SPDE1); (iii) SPD escarificado a cada três anos (SPDE3); (iv) SPD contínuo por 11 anos (SPDC11); (v) SPD contínuo por 24 anos (SPDC24). Os modelos de produção foram: (i) rotação e; (ii) sucessão de culturas. A amostragem foi realizada após 10 e 22 meses da última escarificação no SPDE1 e SPDE3, respectivamente. Nas camadas de 0,0-0,10, 0,10-0,20 e 0,20-0,30 m foram coletadas amostras indeformadas de solo para determinação de atributos físicos (densidade e distribuição do tamanho de partículas, densidade do solo, porosidade total, macro e microporos, resistência do solo à penetração (RP), curva de RP, curva de retenção de água, intervalo hídrico ótimo), e amostras deformadas para determinação de atributos químicos do solo (acidez do solo, macronutrientes, carbono, nitrogênio). Nas profundidades de 0,10 e de 0,20 m, foi determinada a taxa de infiltração tridimensional de água e condutividade hidráulica do solo saturado no campo. Foi determinada a produtividade de grãos de soja e de trigo. Não houve interação entre os sistemas de manejo do solo e os modelos de produção. As variáveis analisadas não foram alteradas em função dos modelos de produção. Os atributos químicos não foram limitantes a produtividade de grãos de soja. Os atributos físicos indicam que os efeitos residuais da escarificação do solo não persistem por um período maior do que 10 meses. O aumento do tempo de adoção do SPD de 11 para 24 anos favoreceu melhorias na qualidade física do solo. O SPDC24 apresentou maior produtividade de grãos de soja do que o SPC. A escarificação do solo não resultou em aumento de produtividade de grãos de soja e de trigo em comparação com SPD. O aumento do tempo sem revolvimento do solo, em uma mesma densidade do solo e conteúdo de água, favorece incrementos na resistência da estrutura do solo. Os limites críticos de RP de 2 MPa são inadequados para avaliação da qualidade física do solo em SPD com ou sem escarificação do solo. Estes limites de RP devem ser ampliados para 3 MPa em SPD com escarificação e para 3,5 MPa em SPD consolidado. O intervalo hídrico ótimo, independente do manejo do solo, modelo de produção e limites críticos de RP, não foi um bom indicador da qualidade física do solo.

L’électronique de puissance a un rôle de plus en plus grandissant dans les systèmes de transports : voitures électriques et hybrides, trains et avions. Pour ces applications, la sécurité est un point critique et par conséquent la fiabilité du système de puissance doit être optimisée. La connaissance du temps de fonctionnement avant défaillance est une donnée recherchée par les concepteurs de ces systèmes. Dans cette optique, un indicateur de défaillance précoce permettrait de prédire la défaillance des systèmes avant que celle-ci soit effective. Dans cette thèse, nous nous sommes intéressés à la caractérisation électromécanique des puces de puissance IGBT et MOSFET. L’exploitation de cette caractérisation devrait permettre, à plus long terme, de mettre en évidence un indicateur de l’état mécanique des assemblages de puissance à des fins de fiabilité prédictive
Power electronics has a role increasingly growing up in transport:electric and hybrid vehicles, trains and aircraft. For these applications, security is a critical point, thus the reliability of the power assembly must be optimized. The knowledge of time to failure is very important information for the designers of these systems. Inthis context, an early failure indicator would predict system failuresbefore it becomes effective. In this thesis, we focused on the electromechanical characterization of power transistors: MOSFET and IGBT. Based on these results this electromechanical characterization should help us in the longer term, to highlight an early failure indicator of the power assembly

Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.

AbstractCompetitive industrial transmission systems must perform most efficiently with reference to complex requirements and conflicting key performance indicators. This design challenge translates into a high-dimensional multi-objective optimization problem that requires complex algorithms and evaluation of computationally expensive simulations to predict physical system behavior and design robustness. Crucial for the design decision-making process is the characterization, ranking, and quantification of relevant sources of uncertainties. However, due to the strict time limits of product development loops, the overall computational burden of uncertainty quantification (UQ) may even drive state-of-the-art parallel computing resources to their limits. Efficient machine learning (ML) tools and techniques emphasizing high-fidelity simulation data-driven training will play a fundamental role in enabling UQ in the early-stage development phase.This investigation surveys UQ methods with a focus on noise, vibration, and harshness (NVH) characteristics of transmission systems. Quasi-static 3D contact dynamic simulations are performed to evaluate the static transmission error (TE) of meshing gear pairs under different loading and boundary conditions. TE indicates NVH excitation and is typically used as an objective function in the early-stage design process. The limited system size allows large-scale design of experiments (DoE) and enables numerical studies of various UQ sampling and modeling techniques where the design parameters are treated as random variables associated with tolerances from manufacturing and assembly processes. The model accuracy of generalized polynomial chaos expansion (gPC) and Gaussian process regression (GPR) is evaluated and compared. The results of the methods are discussed to conclude efficient and scalable solution procedures for robust design optimization.

Stress is a physiological and psychological response to the perception of danger and threat. Stress can occur due to a physical injury, mechanical disturbance, chemical change, or emotional factor. Stress can occur at all ages, including children and adolescents. Various physical and psychological events can cause stress in children, for example suffering from an illness, injury/trauma, parental divorce, parental death, sexual abuse, natural disasters, war, etc. Various exposures to physical and psychological stress harmful to the body can cause it to carry out defense mechanisms against these threats, one of which is changes in the cortisol hormone. Cortisol hormone is used as a biochemical marker for acute and chronic stress. The increase in this hormone as an indicator of stress can be changed through psychosocial interventions, one of which is by the provision of music therapy. Music therapy can manage stress problems of people at various ages with minimal side effects and a small amount of money. It is also easy to apply and does not require any intellectual ability to interpret. There are no limitations for users to use music therapy.

From an engineering point of view, the survivability of a system is defined as its ability to continue to operate despite a natural or human-made disturbance; for example a serious mechanical fault, a human error, or a malicious cyber or physical attack. In the context of critical infrastructures, due to their relevance for the public wellness, it is mandatory to improve the robustness of such systems in order to ensure the availability of essential services such as the distribution of water, gas and electrical power. Nowadays, due to the increasing number of cyber incidents, the definition of protection strategies, able to improve the survivability level of this infrastructure, is at the heart of the scientific debate. In this chapter we propose a procedure based on three steps aimed at improving infrastructure survivability. In the first stage we propose some approaches to identify the criticality degree of each subsystem composing the infrastructure, in the second stage we propose a method to aggregate multiple criticality evaluations performed by subject matter experts by providing a unique holistic indicator. Finally, on the basis of such indicator, we propose a protection strategy to improve the robustness of the entire system.

Aluminum alloys are less corrosion resistance compared to the pure aluminum. The less corrosion resistance of the aluminum alloys results from trading their mechanical strength and stability with their corrosion resistance. Aluminum alloys show inhibition in alkaline, acidic, neutral chloride free, and chloride media. This study covers studies done on different inhibitors used in corrosion inhibition of aluminum alloys in various media. Generally, the inhibition efficiency of the inhibitors increases with increase in the concentration of the inhibitors. The inhibition efficiency also depends on the characteristic of the inhibitor; whether it is a mixed-type, anodic, or cathodic inhibitor. The experimental data fit in Langmuir adsorption isotherm indicates physical adsorption, while Gibb’s free energy values show that aluminum alloys’ corrosion inhibition is by spontaneous adsorption process. The addition of chloride in alkaline solution improves corrosion inhibition of aluminum alloys.

The present paper aims to investigate geotechnical parametric effects on the expansion behavior of clayey soils in Tebessa province northeast of Algeria using the Design Of Experiments (DOE) methodology. It has been used as powerful tools based on physical and mechanical properties, data results obtained within laboratory soil mechanics testing. This statistical tool methodology presents the factor screening design to determine the effect of different parameters such as dry unit weight, saturation degree, water content, plasticity index, etc., on the swelling pressure parameter which can be used as expansion behavior of clay indicator. All data previously collected in the studied prone area allows the ability of detailed analysis using design of experiment and parametric optimization process with response surface methodology (RSM). Each variable that present effects on swelling pressure is also discussed. Besides, the obtained models and equations related the factors affecting the expansion process have been determined. At the output process; the response desirability of the screening design methodology can be optimized by maximization or minimization of the optimal values affecting the swelling behavior. This process allows us to find the best describing models, whereas output results may be compared to empirical laboratory tests results to assess the RSM models.

The physics of pressure, flow and the gas laws have been discussed in Chapter 7 in relation to the behaviour of gas and vapour. This section will focus on the physical principles of the measurement of gas pressure, volume and flow. Unlike a liquid, a gas is compressible and the relationship between pressure, volume and flow depends on the resistance to gas flow (or impedance if there is a frequency dependence between pressure and flow in alternating flow, see Chapter 4 for the electrical analogy of this) in conduits (bronchi, anaesthetic tubing); it also depends on the compliance of structures being filled and emptied (alveoli, reservoir bags, tubing or bellows). Normal breathing occurs by muscular expansion of the thorax, thus lowering the intrathoracic pressure, allowing air or anaesthetic gas to flow towards the alveoli down a pressure gradient from atmospheric pressure. When positive pressure ventilation occurs, gas is ‘pushed’ under pressure into the alveoli. Depending on the exact relationship between the ventilator and the lungs, different relationships exist between airway pressure (rather than alveolar pressure, which cannot easily be measured) and gas flow and volume. Gas pressure measurement devices were traditionally in the form of an aneroid barometer, a hollow metal bellows calibrated for pressure and temperature, which contracts when the external pressure on it increases, and expands when it decreases. The movement is linked to a pointer and indicator dial. It is often more convenient to make the device in the shape of part of a circular section, but the principle is the same. This is what the Bourdon gauge, which commonly measures pressure in gas cylinders, looks like. The detection of movement of the diaphragm of an aneroid barometer can take several forms. The movement can either be linked via a direct mechanical linkage to a pointer, or diaphragm movement can be linked to a capacitative or inductive element in an electrical circuit, such as a Wheatstone bridge. Airway pressure during spontaneous breathing or artificial ventilation is low. The preferred units of measurement are cm H2O and the range of values is between −20 and +20 cmH2O. The aneroid barometer to measure this will therefore be of light construction, using thin copper for the bellows material.

The health of a mechanical component deteriorates over time and its service life is randomly distributed and can be modeled by a stochastic deterioration process. For most of the mechanical components, the deterioration process follows a certain physical laws and their mean life to failure can be determined approximately by these laws. However, it is not easy to apply these laws for mechanical component prognostics in current health monitoring applications. In this paper, a stochastic modeling methodology for mechanical component prognostics with condition indicators used in current health monitoring applications is presented. The effectiveness of the methodology is demonstrated with a real shaft fatigue life prediction case study.

Field extracted electrical assemblies, subjected to harsh environments including storage, and transportation may have often sustained degradation in their material properties and physical structure, without exhibiting external signs of damage. The lack of macro-indicators of damage makes the quantification of sustained damage and the remaining useful life challenging for assessment of the reliability makes quantification of accrued damage and remaining useful life much difficult. The operation environment requires survivability under high-g loads often in excess of 10,000g-100,000g. The need of non-destructive test methods for determination of the internal damage and the assessment of expected operational reliability under the presence of accrued damage from prolonged storage is extremely desirable. While a number of non-destructive test methods such as x-ray, and acoustic imaging exist in the state-of-art — they are limited to the acquisition of imaging of the internal damage state without the ability of conducting measurement of deformation under the action of environment loads. There is scarcity of literature on studying progressive damage to the physical structure of fuze components when subjected to high g shocks. Previously, researchers have studied the reliability of fuze subjected to high-temperature and high-g mechanical shocks, measured redundancy and reliability of fuze electronics through prediction of failure rates and MTTF using MIL-HDBK-217F standard, and performed on fault diagnosis. In this paper, a full-field deformation measurement technique has been presented to monitor damage in key components of the fuze after exposure to multiple high G shocks. Fuze assembly has been subjected to 30,000g mechanical shock until failure. The fuze assembly is CT scanned at regular intervals and the scan data is compared to the pristine scan data to compute physical deformations and damage sustained during the mechanical shock event.

Abstract Electromechanical brake (EMB) is a novel braking mode for railway trains. The reliability of the braking system is important for railway system safety. According to the RAMS (Reliability, Availability, Maintainability and Safety) requirements for railway applications, the key issues of prognostics and health management (PHM) for EMB systems are discussed at first. Consequently, the dominant tasks of the PHM system are confirmed, containing the battery State-of-Charge (SOC) and State-of-Health (SOH) estimation, electric components condition monitor, and mechanical crack prediction. Then the critical failure modes of the EMB system and their failure mechanisms are analyzed. Based on the above analysis, a PHM system developed for EMB systems and its working flow are introduced. The vehicle operation parameters, the brake control commands, and the sensor signals are inputs of the PHM system. These inputs are processed and gathered as health indicators. Then the PHM system adopts the physical model or the hybrid algorithms to track the failure mode and components. Finally, the PHM system locates the health stage of the EMB system. The primary health indicators for EMB systems are the braking distance and emergency battery capacity. And the health indicators for components are mapped with the corresponding failure modes. The estimation for the battery SOC and SOH is established based on the test results of battery properties. The model-based and data-driven hybrid method is utilized to detect the crack growth of mechanical components and the degradation in electric properties. The PHM system is useful for condition-based maintenance. And it is meaningful for the reliability and safety improvement of the EMB systems.

The objective of this study was to implement the Lazy Parts Indicator Method (LPIM) in the analysis of a remote control (RC) car to identify potential parts for mass reduction. In addition, an example of how the method can be used in conjunction with a part redesign process has been shown through topology optimization of an identified part. The LPIM, which was originally developed for the analysis of automobiles, serves as a set of guidelines for novice designers to identify components that have potential for mass reduction. By successfully using the method on a RC car, the method can be shown to be applicable on smaller scale. The analysis of the RC car consisted of using indicators to identify lazy parts, weighing of those parts, and estimation of mass reduction percentages. From this, it was estimated that approximately 5% of the vehicle’s weight could be reduced. Once the lazy analysis was completed on the car, a component with a high potential for mass reduction was selected for redesign. Topology optimization using ANSYS Mechanical was done to suggest a new design, which contained regions of material removal. After creating a redesigned part, a new mass was measured and used to validate the original mass reduction estimates from the LPIM. The new part design was also validated through physical experimentation in which the part was fabricated and tested. This paper outlines an entire process for lightweight design from start to finish, beginning with an identification of parts with mass reduction using the Lazy Parts Indicator Method.

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.

The use of wood as a natural and environmentally friendly material is expanding, but to increase the rationality of its use, it is necessary to know the qualitative indicators of this variable material. They depend on the species, the age of the tree, the region and the growing conditions. Evaluation of the quality of wood involves experiments that require time and special equipment. The least time-consuming procedure for assessing the quality of wood is to use macrostructure parameters, which include the percentage of late wood and the width of the annual layer. The width of the annual layer can be easily measured not only in the laboratory, but also in the field. The purpose of the study was to establish the nature of the change in the percentage of late wood in Scots pine from the forest-steppe zone along the radius of the trunk, as well as the parameters of the width of the annual layer, at which the percentage of late wood will be of the greatest importance. The percentage of late wood affects the physical and mechanical properties of wood, the greater its value, the better the wood.

The research was carried out in Aleksandras Stulginskis University with a natural magnesium mineral fertilizer – magnesium silicate Serpentine rocks that were grounded and granulated with an impact granulation technology, organic cattle manure compost fertilizer, which was granulated using a device with a horizontal granulator matrix (the diameter of pellets is 6 mm), and the mixture of Serpentine and manure pellets (mixture ratio 1:1, diameter of pellets is6 mm). There were investigated and estimated the biometric and physical-mechanical properties of produced fertilizer granules – pellet granulometric composition and biometric indicators, moisture content, density and pellet strength (resistance to impact forces). Research results showed that the pellet moisture content was sufficiently low, varied from 4.7 % to 14.7 %, and the density of produced pellet was considerably high as it reached more than 1000 kg m-3 DM (dry matter). Results on resistance to the deformation of the investigated mineral magnesium and organic fertilizers indicate that the most resistant granules are the ones that are made of the mixture of Serpentine and manure pellets as they decompose to 550.5 N force, whereas granules of manure pellets (without Serpentine) disintegrate to a 271.4 N force, which is about twice as small as the above mentioned one. Research results have shown that fertilizer granules made of organic manure and mixture with magnesium silicate Serpentine are of high quality, these granules are sufficiently resistant to compression on a static force as well as convenient for storage, transportation and mechanical spreading in the field.

Abstract Laser powder-bed fusion is an additive manufacturing (AM) process that offers exciting advantages for the fabrication of metallic parts compared to traditional techniques, such as the ability to create complex geometries with less material waste. However, the intricacy of the additive process and extreme cyclic heating and cooling leads to material defects and variations in mechanical properties; this often results in unpredictable and even inferior performance of additively manufactured materials. Key indicators for the potential performance of a fabricated part are the geometry and temperature of the melt pool during the building process, due to its impact upon the underlining microstructure. Computational models, such as those based on the finite element method, of the AM process can be used to elucidate and predict the effects of various process parameters on the melt pool, according to physical principles. However, these physics-based models tend to be too computationally expensive for real-time process control. Hence, in this work, a hybrid model utilizing neural networks is proposed and demonstrated to be an accurate and efficient alternative for predicting melt pool geometries in AM, which provides a unified description of the melting conditions. The results of both a physics-based finite element model and the hybrid model are compared to real-time experimental measurements of the melt pool during single-layer AM builds using various scanning strategies.

The main tasks of improving the crushed stone-mastic coatings of forest timber highways through the use of innovative road-building materials are considered. Such roads are characterized by the use of materials capable of meeting the basic requirements for transport and operational conditions in difficult natural and climatic conditions. The known road building materials are distinguished by the instability of their physical and mechanical properties. This causes significant difficulties both in the design and in the operation of forest timber roads made of these materials. Despite the complex of experimental studies carried out, the task of developing road coatings with adjustable performance properties remains unfulfilled. Thus, the developed method of designing the grain composition of crushed stone-mastic asphalt concrete pavements of forest roads, with new transport and operational parameters, taking into account the operating conditions, which determined the purpose of this work, will help to solve the problem. The aim of the research was to develop methods for creating crushed-night-mastic asphalt concrete pavements of forest timber roads, using a heat stabilizing additive from expanded vermiculite sand. In this work, the problem of assessing the degree of influence of the addition of sand from expanded vermiculite on the quality indicators of crushed stone-mastic asphalt concrete coatings of forest timber roads was solved. The results of the work were the creation of a formulation of crushed stone-mastic asphalt concrete with a heat-stabilizing additive from expanded vermulite of fraction from 0.5 to 1.0 mm. Taking into account the sufficient adequacy of experimental research, the results of the selection of the mixture can be recommended for use in the practice of building forest timber roads for I and II road-climatic zones.