Implications of processed material in the atmospheres of LMC B supergiants

2008 ◽  
pp. 294-295
Author(s):  
Bruce Bohannan ◽  
Edward L. Fitzpatrick
Keyword(s):  
Processed Material

Nuclear Processes Related to the Ap Stars and the Heaviest Chemical Elements

1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Chemical Elements ◽  
Fission Products ◽  
Abundance Pattern ◽  
Isotopic Shifts ◽  
Processed Material ◽  
R Process ◽  
Ap Stars ◽  
Nuclear Processes

SummaryIsotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.

The analysis of an intense and deformation condition of shaving and glue mix in a rolling zone

2016 ◽  
Author(s):  
В.В. Сергеевичев ◽  
А.В. Сергеевичев ◽  
А.Е. Михайлова
Keyword(s):  
Deformation Condition ◽  
Composition Material ◽  
Continuous Change ◽  
Contact Points ◽  
Processed Material ◽  
The Press ◽  
Dangerous Place ◽  
Variable Tension ◽  
Press Equipment ◽  
Width Reduction

При прохождении стружечноклеевой массы по ленточному прессу и формования ее в изделие под вальцами происходит постоянное изменение свойств материала. От несвязной сыпучей композиции материал в результате пьезотермообработки должен преобразоваться в монолитное фасонное изделие. Силовое и температурные воздействия в процессе обработки вызывают в материале, а затем и в готовом изделии переменное напряженное состояние, которое в значительной степени определяет целостность и окончательные механические свойства готовой продукции. В настоящей статье исследуются напряженные состояния в наиболее опасном месте пресса – под профилирующим вальцом. Основная цель исследования заключается в попытке объяснить появление дефектов изделия и наметить конструктивные и технологические мероприятия по их устранению или хотя бы смягчению. При проведении предварительных экспериментов по изготовлению погонажных изделий из стружечноклеевой массы был обнаружен ряд основных недостатков. Большинство дефектов связано с процессом профилирования и возникают под профилирующим барабаном. Очевидно, причиной всех отмеченных дефектов являются экстремальные условия деформирования материала под барабаном и несоответствие термомеханического состояния обрабатываемого материала характеру деформирования. На основании проведенных исследований можно сделать основные выводы: продольный изгиб при прокатке изделий из стружечноклеевой массы представляет существенную опасность и может быть причиной расслоения изделий по ширине; уменьшение вредного влияния продольного изгиба по ширине изделия может быть достигнуто за счет его интенсивного разогрева и ограничения отверждения связующего под вальцами; диаметры профилирующих барабанов необходимо делать максимальными по конструктивным соображениям; оптимальным вариантом является профилирование на прямолинейных участках, где радиус равен бесконечности; необходимо обеспечить жесткую синхронизацию линейных скоростей по всем точкам контакта изделия с рабочими органами прессового оборудования. Такие условия автоматически удовлетворяется в гусеничном прессе, что дополнительно характеризует его достоинства. When shaving and glue mix passing through a tape press and its formations to product under rollers there is a continuous change of properties of material. From incoherent loose composition material as a result of a pyezoterm processing has to be transformed to a monolithic shaped product. Power and temperature influences in processing cause in material, and then and in a finished product a variable tension which substantially defines integrity and final mechanical properties of finished goods. In the present article intense states in the most dangerous place of a press – under the main roller are investigated. The main objective of research consists in attempt to explain emergence of defects of a product and to plan constructive and technological actions for their elimination or at least to mitigation. When carrying out preliminary experiments on production wooden materials from shaving and glue mix has been found a number of the main shortcomings. The majority of defects is connected with process of profiling and arise under a main drum. Obviously, extreme conditions of deformation of material under a drum and discrepancy of a thermomechanical condition of the processed material to nature of deformation are the reason of all noted defects. On the basis of the conducted researches it is possible to draw the main conclusions: the longitudinal bend when rolling products of shaving and glue mix constitutes essential danger and can be the cause of stratification of products on width; reduction of an adverse effect of a longitudinal bend on width of a product can be reached at the expense of its intensive warming up and restriction of curing binding under rollers; diameters of main drums need to be done maximum for constructive reasons; an optimal variant is profiling on straight sections where radius is equal to infinity; it is necessary to provide rigid synchronization of line speeds on all contact points of a product with operating parts of the press equipment. Such conditions it is automatically satisfied in a truck press that in addition characterizes its advantages.

Microwave Field Distribution Uniformity Coefficient in the Grain Mass

2020 ◽  
Vol 67 (2) ◽  
pp. 87-92
Author(s):  
Dmitriy A. Budnikov
Keyword(s):  
Electromagnetic Field ◽  
Numerical Experiment ◽  
Microwave Field ◽  
Research Purpose ◽  
Coefficient Of Determination ◽  
Material Research ◽  
Dense Layer ◽  
Uniformity Coefficient ◽  
Average Value ◽  
Processed Material

The article considers the microwave electromagnetic fields as one of the options for improving the thermal drying of grain. Their application is limited by the high unevenness of the field propagation in the layer of the processed material. (Research purpose) The research purpose is in justifying the uniformity of distribution of microwave field in the layer of the processed grain. (Materials and methods) The article presents the scheme of computer models of microwave processing zones and waveguides, properties of materials for conducting a numerical experiment. (Results and discussion) A numerical experiment was performed to determine the uniformity coefficient of propagation of the microwave field in a layer of grain material. The article presents the dependencies. (Conclusions) It was found that the results of modeling the distribution of the electromagnetic field in the zone of microwave convective influence of the installation containing two sources of microwave power for processing the grain layer indicate a high level of its unevenness in the volume of the product pipeline. To assess the uniformity of the distribution of the electromagnetic field in the working area of a laboratory installation, there used a coefficient that is the ratio of the average value of the intensity in the zone of microwave convective action to its average value of the wave strength passing through the output of the waveguide. The values of the uniformity coefficient in the considered implementation options are in the range of 0.1757-0.4946 for a dense layer of wheat. To ensure a sufficient level of uniformity of the electromagnetic wave distribution in the volume of the microwave convective zone, the uniformity coefficient must be higher than 0.37. The article presents the dependence of the uniformity coefficient of the electromagnetic field on the humidity of the processed material by a third-degree polynomial with a coefficient of determination higher than 0.98.

Improvement in the quality of the processed material surfaces lies in the moving of nozzle in the cavitation processing

2021 ◽  
pp. 101206
Author(s):  
Masataka Ijiri ◽  
Koji Yamaguchi ◽  
Shoichi Kikuchi ◽  
Masakazu Fujiwara ◽  
Yuki Nakanishi ◽  
...  
Keyword(s):  
Material Surfaces ◽  
Processed Material

scholarly journals Evolution of O stars and the WR connection

1979 ◽  
Vol 83 ◽  
pp. 431-445 ◽  
Author(s):  
Peter S. Conti
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
High Luminosity ◽  
Loss Mechanism ◽  
Evolutionary Scenario ◽  
Processed Material ◽  
Dominant Process ◽  
Highly Evolved ◽  
Loss Rates ◽  
Enriched Composition

The stellar wind mass loss rates of at least some single Of type stars appear to be sufficient to remove much if not all of the hydrogen-rich envelope such that nuclear processed material is observed at the surface. This highly evolved state can then be naturally associated with classic Population I WR stars that have properties of high luminosity for their mass, helium enriched composition, and nitrogen or carbon enhanced abundances. If stellar wind mass loss is the dominant process involved in this evolutionary scenario, then stars with properties intermediate between Of and WR types should exist. The stellar parameters of luminosity, temperature, mass and composition are briefly reviewed for both types. All late WN stars so far observed are relatively luminous like Of stars, and also contain hydrogen. All early WN stars, and WC stars, are relatively faint and contain little or no hydrogen. The late WN stars seem to have the intermediate properties required if a stellar wind is the dominant mass loss mechanism that transforms an Of star to a WR type.

Interfaces in Structural Ceramics

MRS Bulletin ◽  
1990 ◽  
Vol 15 (10) ◽  
pp. 51-59 ◽  
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Structural Ceramics ◽  
Interface Engineering ◽  
Micro Structure ◽  
Complete Understanding ◽  
Intimate Contact ◽  
Transmission Electron ◽  
Processed Material ◽  
Wide Range ◽  
Alternative Materials ◽  
The Relationship

Structural ceramics are necessarily polycrystalline and their usefulness is largely determined by the interfaces between the grains. The relationship between the structure and chemistry of different interfaces and the micro-structure can be illustrated by reviewing studies of interfaces in a wide range of materials including such classical ceramics as Al2O3, the current “hightech” polyphase ceramics exemplified by ZrO2-toughened Al2O3, and the composite materials of the future. Using transmission electron microscopy is essential for a complete understanding, but limitations to its use must be recognized. Only by understanding the factors that control the behavior of these interfaces will it become possible to further extend the application of interface engineering.Structural ceramics are a group of materials that can be used for applications requiring their strength to persist at high temperatures or in conditions that would be particularly corrosive to alternative materials, which are usually metallic. Strength and strength-related properties such as toughness depend largely on the microstructural features of the processed material.The microstructure is defined by the morphology and size of the grains and the interfaces between these grains. If the grains are in intimate contact, then the interface is a grain boundary of the type familiar from studies of metals.

Invariant stress state parameters for forging upsetting of magnesium in the shell

2021 ◽  
Vol 23 (1) ◽  
pp. 79-88
Author(s):  
Yuriy Loginov ◽  
◽  
Yuliya Zamaraeva ◽  
◽  
◽  
...  
Keyword(s):  
Stress State ◽  
Deformable Body ◽  
Great Influence ◽  
Precipitation Process ◽  
Software Module ◽  
Plastic Properties ◽  
Compressive Stresses ◽  
Element Simulation ◽  
Processed Material ◽  
Mathematical Evaluation

Introduction. For pressure treatment of low-plastic metals, it is necessary to develop special techniques for increasing plasticity. In the cold state, an increase in plastic properties is possible due to an increase in the level of compressive stresses during deformation. In the processes of forging precipitation, this is achieved by using shells or clips of various types. At the same time, the configuration of the precipitation tool also matters. To create additional compressive stresses and increase the ductility of the metal, the working surface of the tool can be configured differently than with a normal free draft, where it is obviously larger than the contact surface area of the workpiece, so that metal broadening can occur. The stress state has a great influence on the plasticity of the processed material. This state is described by methods of tensor representation, but to assess the situation, it is customary to use invariants of tensors in one form or another, which eliminates the influence of coordinates on the results of the analysis. In the sections of deformable body mechanics dealing with the influence of the stress state on plasticity, the first, but sometimes other invariants of the stress tensor are used, the invariants themselves are transformed into the stress state indicator and the lode coefficient. The aim of the work: mathematical evaluation of invariant parameters of the stress state of the magnesium precipitation process at room temperature, according to the results of which it is possible to obtain a positive result in real experiments. Research methods: finite element simulation using the DEFORM software module. Results and discussion. The theoretical justification of increasing the plasticity of the magnesium billet in the process of precipitation in the cage without its compression is carried out. An increase in the stress state index modulo 2...5 times is revealed, which contributes to an increase in the plasticity of the metal. At the same time, a zone with a lode coefficient close to zero is identified. It is adjacent to the middle of the height of the workpiece at the point of contact with the cage and can be a dangerous cross-section from the position of crack formation.

Methods of temperature measurement in microwave heating technologies

2021 ◽  
pp. 20-28
Author(s):  
Boris A. Lapshinov
Keyword(s):  
Temperature Measurement ◽  
Microwave Heating ◽  
Microwave Radiation ◽  
Electromagnetic Fields ◽  
Optical Measurement ◽  
Measurement Methods ◽  
Heating Systems ◽  
Measurement Systems ◽  
Processed Material ◽  
Spectral Pyrometry

In industrial technological processes associated with the heating of the processed material by microwave radiation, it is necessary to measure the temperatures of objects. Methods for measuring temperatures in the fields of technology using microwave heating systems are considered. The main possibilities, disadvantages and limitations of the used contact and non-contact (optical) measurement methods are determined. The requirements for temperature measurement systems under conditions of exposure to strong electromagnetic fields are listed. The possibilities of the spectral pyrometry method are especially noted.

scholarly journals Design Process of Energy Effective Shredding Machines for Biomass Treatment

10.14311/1622 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Juraj Beniak ◽  
Juraj Ondruška ◽  
Viliam Čačko
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Design Process ◽  
Electric Energy ◽  
Point Of View ◽  
Processed Material ◽  
Material Saving

The shredding process has not been sufficiently investigated for the design of better, energy and material saving shredding machines. In connection with present-day concern about the environment, ecology, energy saving, recycling, and finding new sources of energy, we need to look at the design of shredding machinery, the efficiency of the machines that we using, and ways of improving them to save electric energy for their operation. This paper deals with sizing and designing shredding machines from the point of view of energy consumption and optimization for specific types of processed material.

High-Temperature Wear Mechanisms of a Severely Plastic Deformed Al/Mg2Si Composite

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Mahsa Ebrahimi ◽  
Abbas Zarei-Hanzaki ◽  
A. H. Shafieizad ◽  
Michaela Šlapáková ◽  
Parya Teymoory
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
Wear Behavior ◽  
Normal Load ◽  
Aluminum Matrix ◽  
Hardened Layer ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Wear Performance ◽  
Processed Material

The present work was primarily conducted to study the wear behavior of as-received and severely deformed Al-15%Mg2Si in situ composites. The severe plastic deformation was applied using accumulative back extrusion (ABE) technique (one and three passes). The continuous dynamic recrystallization (CDRX) was recognized as the main strain accommodation and grain refinement mechanism within aluminum matrix during ABE cycles. To investigate the wear properties of the processed material, the dry sliding wear tests were carried out on both the as-received and processed samples under normal load of 10 and 20 N at room temperature, 100 °C, and 200 °C. The results indicated a better wear resistance of processed specimens in comparison to the as-received ones at room temperature. In addition, the wear performance was improved as the ABE pass numbers increased. These were related to the presence of oxide tribolayer. At 100 °C, the as-received material exhibited a better wear performance compared to the processed material; this was attributed to the formation of a work-hardened layer on the worn surface. At 200 °C, both the as-received and processed composites experienced a severe wear condition. In general, elevating the temperature changed the dominant wear mechanism from oxidation and delamination at room temperature to severe adhesion and plastic deformation at 200 °C.

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