scholarly journals Review on the Thermal Performance on the Basis of Different Types of Material used in Ball Bearings

2021 ◽  
pp. 61-66
Author(s):  
Vinay Kumar Shukla
Keyword(s):  
Thermal Performance ◽  
Ball Bearings ◽  
Operating Environment ◽  
Rolling Bearings ◽  
Movable Object ◽  
Different Types ◽  
Operations And Maintenance ◽  
Frictional Forces ◽  
Materials Used ◽  
The Impact

Bearing is a movable object, so frictional forces must be overcome in terms of moving the Bearing. To decrease the friction force on the movable methodology, different kinds of bearings have been used. The bearing gets its characterized by the fact that it is used to support a rotating axle or shaft. Because rolling bearings utilize balls or rollers, they are referred to as "rolling components." one can measure bearing expected lifespan depending on the material exhaustion if one can understand the operations and maintenance of loads and speeds. These computations should be based on the assumption that now the bearing is appropriately installed, lubricated, and moreover treated. It is unable to account for the impact of detrimental operating environment. Damaged bearing has a significant economic and industrial implications. Numerous substance are used in the bearing sector to several bearing elements. To achieve maximum bearing performance and durability, the products are deposited to obtain intended characteristics. The components listed in this are the most frequently used. The different materials used in ball bearings are discussed in this paper.

Numerical Modeling and Experimental Research of the Perforation Phenomenon of Certain Materials Used for Individual Protection by Bullets

2017 ◽  
Vol 23 (3) ◽  
pp. 174-179
Author(s):  
Florin Ilie ◽  
Nicolae Moro
Keyword(s):  
Numerical Modeling ◽  
Modeling And Simulation ◽  
Experimental Research ◽  
Ballistic Protection ◽  
Different Types ◽  
Individual Protection ◽  
Range Testing ◽  
Materials Used ◽  
The Individual ◽  
The Impact

Abstract The paper captures two aspects related to the phenomenon of impact between bullets and different types of materials used for the individual protection of the militaries, for the same type of ammunition and for the same configuration of the ballistic protection system, both in the case of the activity of experimental shooting range testing, as well as in the case of the modeling and simulation of the impact between the bullet and the protection materials.

scholarly journals Mathematical model of the impact assessment of roughness and waviness deviations of races surfaces of rolling bearings on the level of generated vibration

Mechanik ◽  
2019 ◽  
Vol 92 (1) ◽  
pp. 35-37
Author(s):  
Paweł Zmarzły
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Impact Assessment ◽  
Ball Bearings ◽  
Vibration Level ◽  
Rolling Bearings ◽  
Shape Deviations ◽  
Specific Frequency ◽  
The Impact ◽  
Dominant Influence

The article presents mathematical models allowing to describe the level of vibration generated by ball bearings 6304-2z type depending on the value of roughness and waviness deviations of inner and outer bearings races. This models will allow to estimate what type of shape deviations have dominant influence on the vibration level generated in specific frequency ranges.

scholarly journals Characteristics of Specialised Firefighter Clothing Used in Poland – the Thermal Parameters

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 65-70
Author(s):  
Magdalena Młynarczyk
Keyword(s):  
Thermal Insulation ◽  
Protective Clothing ◽  
Thermal Parameters ◽  
Thermal Manikin ◽  
Test Results ◽  
Evaporative Resistance ◽  
Different Types ◽  
Local Thermal Insulation ◽  
Materials Used ◽  
The Impact

This paper describes the characteristic thermal parameters of firefighters’ personal protective clothing (FFPPC) used in Poland. The total thermal insulation and evaporative resistance of three different types of FFPPC were measured and used on a thermal manikin. Next, the results were compared. Based on the analyses and calculations of the test results, it was shown that FFPPC provides a barrier to the heat exchange between the user and the surrounding environment. Differences in the local thermal insulation can be triggered not only by the material used but they can also be attributable to clothes fitted on the manikin. The biggest differences can be noted on the segments forming part of the manikin’s trunk. No difference was found in the evaporative resistance between the clothes tested. In order to examine further the impact of the materials used on thermal parameters of protective clothing, it is necessary to carry out an analysis of the impact of individual layers.

SIFAT FISIK DAN MEKANIK PAPAN PARTIKEL DARI LIMBAH PLASTIK JENIS HDPE (High Density Polyetylene) DAN RANTING/CABANG KARET (Hevea brasiliensis Muell.Arg)

2011 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Sari Mirad Noor
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Raw Materials ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Plastic Waste ◽  
High Density ◽  
Different Types ◽  
Materials Used ◽  
The Impact

The need of log increace rapidly, mean while forest product decrease, so efficiency on wood process should be done wisely, in the other hand plastic waste is uncompossed material, become an environmental problems. This research aims to determine the impact of particles of type HDPE plastic wastes and twigs/branches of rubber on some physical and mechanical properties of wood. Physical properties have been tested for water content, density, thickness, and water absorption. Although mechanical properties tests were tough Broken/Module of Rufture (MOR) and the preservation of architecture/modulus of elasticity (MOE).     The raw materials used are polyethylene of high density of waste plastic and rubber adhesive urea formaldehyde branch branch. Experimental design used the randomized Completely Design (RCD) 5 x 4, in which each treatment became much like 5 times replicated).The treatment used is the diversity of the composition of the waste of plastic of different types of polyethylene of high density provides a significant effect on the content of water, water absorption, the density and the development of thickness. With regard to the persistence and the fracture of the arch determination not to give a significant effect.Keywords: physical and mechanical properties, particle board, HDPE plastic waste, branch/twig of  rubber.

Three-layer Permutation of the Phonionic Structure and the Influence of the Environment

2018 ◽  
Vol 69 (9) ◽  
pp. 2571-2574
Author(s):  
Michal Szota
Keyword(s):  
Layer Structure ◽  
Middle Layer ◽  
Production Costs ◽  
Frequency Range ◽  
Different Types ◽  
Transmission Structure ◽  
Materials Used ◽  
The Impact ◽  
Wave Filters ◽  
Different Thickness

The study investigated the influence of permutation of a three-layer structure on the phononic system transmission. Phononic structures are used as mechanical wave filters. These composites are designed and manufactured to have specific properties. The most important property is the presence of phononic bandgaps (PhBG) in these structures. They are designed so that the PhBG occurs in a given frequency range. Knowledge of the impact of deployment of the layets in the structure allows better design of these filters. The analysis was carried out using the transmission matrix method (TMM) algorithm. The transmission structures was examined for all permutations of a system of three layers made of different materials. The structure consisted of mercury, epoxy, rubber and PNM-0.38PT. The materials are chosen so that their characteristics largely differ. The structure was surrounded by water. The tests were carried out for the frequency range up to 1 MHz. Cases with different thickness of layers were analyzed. The tests have shown that regardless of the layer thickness, only three types of transmission structures exist in the six permutations of the system. Systems in which the middle layer remained unchanged, while the outermost layers were changed, were characterized by the same transmission structure. Increasing the thickness of the layers increased the number of transmission bands. Transmission strongly depends on the environment.The absorption of the materials used was not taken into account in the work. Interesting results can be obtained by analyzing the permutation of more complex structures. Changing the order of layers in the filter without changing its characteristics may affect the reduction of production costs and easier design of structures with given properties. The article shows repeating phononic transmission structure for different types of layers alignment.

scholarly journals The Impact of Vegetation on Thermal Performance

2018 ◽  
Vol 3 (11) ◽  
pp. 147
Author(s):  
Alamah Misni
Keyword(s):  
Thermal Performance ◽  
Thermal Environment ◽  
Publishing House ◽  
Landscape Design ◽  
Single Family ◽  
Different Types ◽  
International Publishing ◽  
The Impact ◽  
Family House ◽  
Open Access Article

This paper investigates the effect of vegetation in modifying outdoor temperature around a single-family house in a hot and humid tropical climate. The climatic parameters, house location, and physical characteristics of landscape design are measured and surveyed. The focus of this study is on the impact of trees and different types of foliage on the thermal environment of the houses.  The main findings are that heavily landscape around single-family houses can potentially slow heat build-up by shading, evapotranspiration, and wind channelling by as much as 4°C.Keywords: Single-family house, thermal performance, landscape design, evapotranspirationeISSN 2398-4295 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. http://dx.doi.org/10.21834/ajbes.v3i11.110

scholarly journals Study on the Thermal Performance and Temperature Distribution of Ball Bearings in the Traction Motor of a High-Speed EMU

2020 ◽  
Vol 10 (12) ◽  
pp. 4373
Author(s):  
Yu Wang ◽  
Junci Cao ◽  
Qingbin Tong ◽  
Guoping An ◽  
Ruifang Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Thermal Performance ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Ball Bearings ◽  
Convection Heat ◽  
Rolling Bearings ◽  
Traction Motors

The transient thermal performance of rolling bearings affects the mechanical performance and system safety of traction motors. Most of the traditional empirical formulas used in temperature analysis have been simplified and cannot be completely applied to the calculation of heat generation and convection heat transfer coefficients. Based on the comparative analysis of finite element transient temperature and experimental data, this paper proposes a correction method of mathematical model and derives an accurate calculation formula for the heat generation and lubricant convection heat transfer coefficient of ball bearings applicable for the non-driving end in the traction motor of a high-speed EMU (Electric Multiple Unit). The accuracy of the results has been verified by durability experiment data. In addition, with changes in speed, radial load and other factors taken into account, we have analyzed the influence of these time-varying factors on ball bearing temperature, as well as the temperature distribution law of each component in a grease-lubricated bearing, in a bid to lay a foundation for follow-up research on the heat transfer laws of traction motors and rolling bearings.

Novel Process Techniques to Reduce Voids in Solder Thermal Interface Materials Used for Flip-Chip Package Applications

2005 ◽  
Author(s):  
M. Montano ◽  
J. Garcia ◽  
W. Shi ◽  
M. T. Reiter ◽  
U. Vadakkan ◽  
...  
Keyword(s):  
Process Parameters ◽  
Thermal Performance ◽  
Flip Chip ◽  
Technical Conference ◽  
Thermal Interface Material ◽  
Electronic Systems ◽  
Thermal Interface ◽  
Cure Time ◽  
Materials Used ◽  
The Impact

In the present study, the thermal performance of flip chip electronics packages was evaluated by characterizing the amount of voiding present in the Solder Thermal Interface Material (STIM) which is placed between the die and Integrated Heat Spreader (IHS). The study found that the thermal resistance, Rjc (resistance between the Si die and IHS), is dependent upon the amount of voiding present as well as the location of the voiding in the STIM. The study also described the techniques to reduce the STIM voids in flip chip packages and identified the key process parameters to improve the thermal performance. The process parameters varied in this study consisted of STIM thickness, dwell time and temperature, flux weight, and many others. A detailed DOE and statistical analysis were carried out to determine the impact of the parameters mentioned above toward reducing the quantity of voids in the STIM. The analysis showed that for the packages under consideration, the primary process parameters that affect the STIM voiding are cure time, flux weight and TIM thickness.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

scholarly journals Transient thermal response of opaque building envelope elements: EPFL campus case study

2021 ◽  
Vol 2042 (1) ◽  
pp. 012080
Author(s):  
Mohammad Rahiminejad ◽  
Cécile Berquand ◽  
Dolaana Khovalyg
Keyword(s):  
Thermal Performance ◽  
Thermal Inertia ◽  
Thermal Response ◽  
Weather Conditions ◽  
Energy Performance ◽  
Building Envelope ◽  
Time Shift ◽  
Wall Structure ◽  
Materials Used ◽  
The Impact

Abstract The building envelope acts as a shield against varying weather conditions and modulates thermal energy flow between outdoors and indoors. The choice of layers used in the assembly impacts the heat loss and gain through the wall structure and potentially can affect the comfort indoors. Thus, the building envelope plays an essential role in the thermal performance of the building. Optimizing the cladding design in the envelope has recently become increasingly important to reach sustainable development strategies for reducing greenhouse gas emissions by 2050. This paper aims to analyze several cladding types used on the EPFL campus in Lausanne and compare their impact on the energy performance of the building envelopes. The building assemblies constructed on the EPFL campus in different years vary in composition and thermo-physical properties of the layers used. The impact of these parameters on the thermal performance of the wall assembly is evaluated by comparing the variation of heat flux and temperature fluctuations within the wall structure. The results obtained highlight the importance of the building envelope layers and materials used in the wall structure. Due to the variations in the thermal inertia of different wall assemblies, a time shift of more than 3 hours in the transient response of the building envelope to the fluctuation of the outdoor weather conditions is observed.

Quota Women Are Threatening to Men

2017 ◽  
Vol 76 (3) ◽  
pp. 107-116 ◽  
Author(s):  
Klea Faniko ◽  
Till Burckhardt ◽  
Oriane Sarrasin ◽  
Fabio Lorenzi-Cioldi ◽  
Siri Øyslebø Sørensen ◽  
...  
Keyword(s):  
Decision Making ◽  
Organizational Performance ◽  
Gender Stereotypes ◽  
Perceived Threat ◽  
Preferential Treatment ◽  
Public Sector Employees ◽  
Different Types ◽  
Low Levels ◽  
Women In Decision Making ◽  
The Impact

Abstract. Two studies carried out among Albanian public-sector employees examined the impact of different types of affirmative action policies (AAPs) on (counter)stereotypical perceptions of women in decision-making positions. Study 1 (N = 178) revealed that participants – especially women – perceived women in decision-making positions as more masculine (i.e., agentic) than feminine (i.e., communal). Study 2 (N = 239) showed that different types of AA had different effects on the attribution of gender stereotypes to AAP beneficiaries: Women benefiting from a quota policy were perceived as being more communal than agentic, while those benefiting from weak preferential treatment were perceived as being more agentic than communal. Furthermore, we examined how the belief that AAPs threaten men’s access to decision-making positions influenced the attribution of these traits to AAP beneficiaries. The results showed that men who reported high levels of perceived threat, as compared to men who reported low levels of perceived threat, attributed more communal than agentic traits to the beneficiaries of quotas. These findings suggest that AAPs may have created a backlash against its beneficiaries by emphasizing gender-stereotypical or counterstereotypical traits. Thus, the framing of AAPs, for instance, as a matter of enhancing organizational performance, in the process of policy making and implementation, may be a crucial tool to countering potential backlash.

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