Characterisation of Polytetrafluoroethylene and Fiber Based Gaskets Under Creep and Thermal Ratcheting

2017 ◽  
Author(s):  
Rahul Palaniappan Kanthabhabha Jeya ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Research Work ◽  
Creep Property ◽  
Compressive Load ◽  
Cumulative Damage ◽  
Thermal Ratcheting ◽  
Different Temperatures ◽  
Leak Tightness ◽  
The Impact ◽  
Applied Stresses

The objective of this research work is to typify PolyTetraFluoroEthylene (PTFE) and fiber based gaskets. Recurrent employment of Teflon based gaskets as asbestos gasket replacement in certain applications is due to their effective leak tightness and excellent chemical resistance. The research investigates the effect of cyclic and determinant temperature on the phenomenon of creep and thermal ratcheting under compressive load. The tests are performed at 4000 and 6000 psi compressive stress on virgin PTFE (vPTFE) and expanded PTFE (ePTFE) along with Inorganic Fiber Gaskets (IFG) at different temperatures. The Universal Gasket Rig (UGR) is utilized to perform the convoluted analysis of creep-thermal ratcheting coupling at different stress levels on selected gasket materials. The actual cumulative damage due to thermal ratcheting is separable into upper and lower bound regions indicating the highest and lowest of ratcheting temperature regions. The effect of thermal ratcheting tends to saturate after 12 and 15 cycles for expanded PTFE and fiber gaskets while no saturation is observed with virgin PTFE gaskets even after 20 thermal cycles. IFG and virgin PTFE gaskets exhibited similar percentage of thickness reduction under different applied stresses while expanded PTFE showed a maximum reduction under the least applied stress. The influences of temperature and load are manifested in the compressive creep property which in turn dictates the magnitude of cumulative damage due to thermal ratcheting. Lastly, the impact of creep and thermal ratcheting on the Coefficient of Thermal Expansion (CTE) is evident as the magnitude of CTE upsurges with the extent of induced damage.

Influence of Thermal Ratcheting on the Creep and Mechanical Properties of High Density Polyethylene (HDPE)

2018 ◽  
Author(s):  
Rahul Palaniappan Kanthabhabha Jeya ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Creep Strain ◽  
Coefficient Of Thermal Expansion ◽  
Creep Property ◽  
Compressive Load ◽  
Steady Creep ◽  
Thermal Cycles ◽  
Ratcheting Strain ◽  
Heating And Cooling ◽  
Thermal Ratcheting ◽  
The Impact

The objective of this research is to describe the consequence of thermal ratcheting on the long-term creep property of HDPE material. The thermal ratcheting phenomenon amplifies significantly the creep strain of HDPE in comparison to the steady creep strain under constant temperature. The magnitude of creep strain of HDPE increases by 8% after just 20 thermal cycles between 28 and 50°C. The creep modulus which is inversely proportional to the creep strain depletes further under thermal ratcheting. Both properties change significantly with the number of thermal cycles. The coefficient of thermal expansion (CTE) of HDPE varies with the applied compressive load, with successive thermal cycles and with the thermal ratcheting temperature. The impact of thermal ratcheting diminishes with increase in initial steady creep exposure time-period but still the magnitude cumulative damage induced is noteworthy. The magnitude of growth in creep strain drops from 8 to 2.4% when thermal ratcheting is performed after 1 and 45 days of steady creep, respectively. There is a notable change in thickness of the material with each heating and cooling cycle even after 45 days of creep however, the thermal ratcheting strain value drops by 80% in comparison to thermal ratcheting strain after 1 day of creep and under similar test conditions.

Influence of Thermal Ratcheting on the Creep and Mechanical Properties of High-Density Polyethylene

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Rahul Palaniappan Kanthabhabha Jeya ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Creep Strain ◽  
High Density Polyethylene ◽  
Coefficient Of Thermal Expansion ◽  
Creep Property ◽  
High Density ◽  
Steady Creep ◽  
Thermal Cycles ◽  
Ratcheting Strain ◽  
Thermal Ratcheting ◽  
The Impact

Abstract The objective of this research is to describe the consequence of thermal ratcheting on the long-term creep property of the high-density polyethylene (HDPE) material. The thermal ratcheting phenomenon increases significantly the creep strain of HDPE. The magnitude of the creep strain of HDPE increases by 8% after just 20 thermal cycles between 28 and 50 °C. The creep modulus, which is inversely proportional to the creep strain, depletes further under thermal ratcheting. Both the properties change significantly with the number of thermal cycles. The coefficient of thermal expansion (CTE) of HDPE varies with the applied compressive load, with successive thermal cycles, and with the thermal ratcheting temperature. The impact of thermal ratcheting diminishes with an increase in initial steady creep exposure time period, but still the magnitude cumulative deformation induced is noteworthy. The magnitude of growth in creep strain drops from 8% to 2.4% when thermal ratcheting is performed after 1 and 45 days of steady creep, respectively. There is a notable change in the thickness of the material with each heating and cooling cycle even after 45 days of creep; however, the thermal ratcheting strain value drops by 80% in comparison with the thermal ratcheting strain after 1 day of creep and under similar test conditions.

The Effect of Biaxial Interlocking Block to the Masonry Wall Properties under Uniaxial Compression Load

2021 ◽  
Vol 1041 ◽  
pp. 107-114
Author(s):  
Fauziah Aziz ◽  
Mohd Fadzil Arshad ◽  
Hazrina Mansor
Keyword(s):  
Compressive Strength ◽  
Slenderness Ratio ◽  
Research Work ◽  
Compressive Load ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Masonry Unit ◽  
Compression Load ◽  
The Individual ◽  
The Impact

Biaxial Interlocking Block (BIB) is a new interlocking block system introduced in this research work. BIB was designed and expected to have the capacity to resist the biaxial load. In this research, the production of BIB was introduced, and the properties of BIB as the individual and walling unit was identified. The features of BIB in terms of density, compressive strength and MOE was identified. To define the impact BIB to the masonry wall capacity, nine walls panel and nine prisms including Solid Block (SB) and cement sand brick (CSB) have been constructed and tested under concentric compressive load. From the data obtained, the BIB walling system was calculated and identified. All the properties values of BIB masonry obtained compared with SB and CSB masonry values. The relationship of masonry properties by different types of masonry unit was also identified and discuss. From all the data and analysis carried out, it is found that the features of masonry unit have influenced the walling properties of the constructed wall. The higher compressive strength of masonry unit will enhance the capacity of the masonry walls. From this research, it is also found that BIB is having excellent properties as a walling unit as compare to SB and CSB wall. A linear relationship between the compressive strength of the samples regardless of the changing in masonry unit compressive strength has been found appropriate with the same slenderness ratio. This work offers valuable data of BIB to the masonry walls properties under compressive load.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Static and Dynamic Studies of Gasoline in View of its Octane Number and its Toxic Effect

2013 ◽  
Vol 12 (7) ◽  
pp. 451-459
Author(s):  
Ashraf Yehia El-Naggar ◽  
Mohamed A. Ebiad
Keyword(s):  
Toxic Effect ◽  
Aromatic Hydrocarbons ◽  
Octane Number ◽  
Liquid Fuel ◽  
Positive Impact ◽  
Hydrocarbon Composition ◽  
Different Temperatures ◽  
Different Seasons ◽  
The One ◽  
The Impact

Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel.

Serving the People in Long Beach, California: Advancing Justice for Southeast Asian Youth through Community University Research Partnerships

2019 ◽  
Vol 16 (1-2) ◽  
pp. 1-34
Author(s):  
R. Varisa Patraporn
Keyword(s):  
Asian American ◽  
Research Work ◽  
Community Based Participatory Research ◽  
Youth Empowerment ◽  
Long Beach ◽  
Structured Interviews ◽  
Research Partnerships ◽  
Community Needs ◽  
The People ◽  
The Impact

Khmer Girl’s in Action is a nonprofit that successfully utilizes community-based participatory research (CBPR) with university partners to create social change for youth in Long Beach, CA. Based on semi-structured interviews and content analysis of news articles, I explore the impact and sustainability of this research work and the research partnerships. Findings highlight impacts such as youth empowerment, heightened awareness around community needs, policy change, and CBPR curriculum improvements in the field as impacts. Sustainability requires integrating research into program funding, utilizing a tailored training curriculum, building on community members prior relationships, and selecting partners that share common goals, levels of commitment, and flexibility. As funders demand more data to justify community needs, understanding more examples of such work in the Asian American community will be useful for informing future partnerships.

Impacto de las tecnologías de la información y las comunicaciones: Una mirada en la Educación Superior

2017 ◽  
Vol 1 (6) ◽  
Author(s):  
Karina Virginia Mero Suárez ◽  
Edwin Joao Merchán Carreño ◽  
Ana Del Rocío Fernández Torres ◽  
Narcisa María Crespo Torres
Keyword(s):  
Higher Education ◽  
Information Technology ◽  
Research Work ◽  
Field Research ◽  
Research Problem ◽  
Research Report ◽  
Educación Superior ◽  
Educational Design ◽  
Educacion Superior ◽  
The Impact

El artículo aborda la necesidad de la creatividad que se impone en la era actual del conocimiento y la importancia que  constituyen las tecnologías como herramientas indispensables en todas las esferas de la vida. En Trabajo toma como campo investigativo los cambios que se llevan a cabo en esta esfera en la Universidad Estatal del Sur de Manabí y la Universidad Técnica de Babahoyo, Ecuador, donde se toman como objeto el proceso de enseñanza aprendizaje en la Educación Superior. El objetivo de la investigación fue comunicar el impacto de las Tecnologías de la Información y las Comunicaciones en las Universidades, donde se hace énfasis en el nuevo rol de los docentes y su nuevo desempeño de facilitadores del aprendizaje en los educandos a través en los nuevos escenarios mediados por las tecnologías. Para el desarrollo exitoso de esta memoria investigativa se   usó como metodología instrumentos que se basaron fundamentalmente en documentos referativos que ayudaron a justificar el problema de investigación, el cual consistía fundamentalmente en el impacto de las nuevos  dispositivos tecnológicos y su utilidad en los centros de altos estudios del país. Se concluyó que las Tecnologías de la Información y Comunicación son herramientas indispensables en la docencia y al mismo tiempo la forma de intervenir en el diseño educativo que nos llevan a explorar nuevos métodos docentes en los escenarios educativos mediados por estas. Se constató además que estas herramientas favorecen satisfactoriamente al proceso si se tiene una buena preparación por parte del docente.   Palabras clave: Herramientas tecnológicas, universidades, formación, docencia universitaria, proceso de enseñanza – aprendizaje Impact of information technology and communications: a look at higher education  Abstract The article states the need of the creativity that prevails in the current era of knowledge and the importance that technologies constitute in all spheres of life. In field research work it takes as changes take place in this area in Southern State University of Manabí and the Technical University of Babahoyo, Ecuador, where they are taken as an object the process of learning in higher education. The aim of the research was to communicate the impact of Information Technology and Communications in the universities, where the emphasis is on the new role of teachers and their new performance of facilitators of learning in students through the new scenarios mediated by technologies. For the successful development of this research report it was used as a methodology instruments based mainly on referative documents that helped to justify the research problem, which consisted mainly of the impact of new technological devices and their use in the centers of higher learning in the country. It was concluded that information technology and communication are indispensable tools in teaching and at the same time how to intervene in the educational design that lead us to explore new teaching methods in educational settings mediated by these. It was further found that these tools successfully promote the process if there is a good preparation by the teacher.

An Energy Efficient Spectrum Aware Routing for Cognitive Radio Networks (CRNs)

2020 ◽  
Vol 10 ◽  
Author(s):  
Dileep Reddy Bolla ◽  
Jijesh J J ◽  
Mahaveer Penna ◽  
Shiva Shankar
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Energy Efficient ◽  
Research Work ◽  
Spectrum Management ◽  
Residual Energy ◽  
Radio Networks ◽  
Traffic Load ◽  
The Impact

Back Ground/ Aims:: Now-a-days in the Wireless Communications some of the spectrum bands are underutilized or unutilized; the spectrum can be utilized properly by using the Cognitive Radio Techniques using the Spectrum Sensing mechanisms. Objectives:: The prime objective of the research work carried out is to achieve the energy efficiency and to use the spectrum effectively by using the spectrum management concept and achieve better throughput, end to end delay etc., Methods:: The detection of the spectrum hole plays a vital role in the routing of Cognitive Radio Networks (CRNs). While detecting the spectrum holes and the routing, sensing is impacted by the hidden node issues and exposed node issues. The impact of sensing is improved by incorporating the Cooperative Spectrum Sensing (CSS) techniques. Along with these issues the spectrum resources changes time to time in the routing. Results:: All the issues are addressed with An Energy Efficient Spectrum aware Routing (EESR) protocol which improves the timeslot and the routing schemes. The overall network life time is improved with the aid of residual energy concepts and the overall network performance is improved. Conclusion:: The proposed protocol (EESR) is an integrated system with spectrum management and the routing is successfully established to communication in the network and further traffic load is observed to be balanced in the protocol based on the residual energy in a node and further it improves the Network Lifetime of the Overall Network and the Individual CR user, along with this the performance of the proposed protocol outperforms the conventional state of art routing protocols.

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