Study on Microwave Curing Behavior and Performance of Epoxy/Versamid 125

2012 ◽  
Vol 430-432 ◽  
pp. 281-284 ◽  
Author(s):  
Yun Bo Lei ◽  
Xue Juan Cao
Keyword(s):  
Room Temperature ◽  
Bending Strength ◽  
Good Condition ◽  
Curing Time ◽  
Epoxy System ◽  
Microwave Technology ◽  
Microwave Curing ◽  
And Performance ◽  
The Impact ◽  
Impact Ductility

The curing rate of epoxy/Versamid 125 (V125) by heating curing, room-temperature curing and microwave curing was compared. It is founded that applying microwave technology could effectively improve the curing rate and the curing time is only 3-4minutes. 140W microwave could cure the epoxy system in good condition, but 280W and 420W were easy to make the materials coking. The impact of diluent on mechnical properties of curing product were studied and it is showed that the impact strength increases and the impact ductility will be improved with the content of diluent increases, while the compressing strength, bending strength and tensile strength decrease.

Studies on Mechanical and Thermal Properties of Epoxy Resin Modified by Fluorine-Containing Silicone

2013 ◽  
Vol 401-403 ◽  
pp. 713-716
Author(s):  
Cheng Fang ◽  
Dong Bo Guan ◽  
Wei Guo Yao ◽  
Shou Jun Wang ◽  
Hui An
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Bending Strength ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Epoxy System ◽  
Resin Curing ◽  
The Impact ◽  
Modified Epoxy

The epoxy resin was modified with the mixture of α,ω-dihydroxy poly-(3,3,3-trifluoropropyl) siloxane (PTFPMS), KH560 and stannous octoate. KH560 can react with PTFPMS and also epoxy resin curing agent. The two reactions were characterized by FI-IR. The modified epoxy resin was characterized by FI-IR. The result showed that fluorine-containing silicone had been successfully introduced into the epoxy system. The mechanical and thermal properties of the modified epoxy resin were analyzed. The results showed that with the increase of PTFPMS the impact strength of epoxy resin increased, hardness and bending strength correspondingly reduced, slight decrease in the glass transition temperature.

Diamond Tools Matrix Composites of Co Replaced by Fe with Doping Rare Earth

2012 ◽  
Vol 424-425 ◽  
pp. 848-851 ◽  
Author(s):  
Qing Hua Zou
Keyword(s):  
Rare Earth ◽  
Bending Strength ◽  
Service Performance ◽  
Rare Earth Doping ◽  
Matrix Composites ◽  
Metal Powders ◽  
Diamond Tools ◽  
Process Route ◽  
The Impact ◽  
Impact Ductility

The experiment on adding rare earth elements doped in diamond matrix composites is made. Based on the doping of rare earth in metal powders including tungsten carbide, iron and nickel, Co is entirely replaced by Fe with rare earth in diamond matrix composites, and the process route of rare earth doping is indicated. The related performance of is measured, and the results obtained show that the bending strength, the hardness and the impact ductility of Fe matrix composites with rare earth are improved. The practical service performance of Fe matrix composites with rare earth has reached up to the practical service performance of Co matrix, and bearing good practical service performance, low price, have made corresponding diamond tools.

scholarly journals Investigations on Flexural and Compressive Strengths of Mortar Dedicated to Clinker Units—Influence of Mixing Water Content and Curing Time

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 347
Author(s):  
Jan Kubica ◽  
Iwona Galman
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Laboratory Tests ◽  
Bending Strength ◽  
Mechanical Parameters ◽  
Curing Time ◽  
The Impact ◽  
Mixing Water

The article presents laboratory tests on the impact of the mixing water content used in the preparation of fresh mortar on the flexural and compressive strength of one of the dry-mix mortars produced by a leading European producer and dedicated to bricklaying with clinker elements. The development of these parameters in relation to curing time was also analyzed. The mortar samples were prepared from a factory-made mortar mix using 4.0 L (the value recommended by the mortar manufacturer), 4.5 L, and 5 L of water per 25 kg bag of ready-made, pre-mixed dry mortar mix. All samples were tested in five series after 5, 9, 14, 21, and 28 days of sample curing. The results of these tests showed that the use of 6 and 18% more mixing water than recommended by the manufacturer (4.5 and 5 L per bag) adversely affected the basic mechanical parameters of the tested mortar. Moreover, it was found that the highest compressive strength values were obtained after 21 days of curing and not after 28 days as usual. It was also found that hardening time and higher than recommended water content adversely affected the bending strength of the mortar.

scholarly journals The Compositions: Biodegradable Material – Synthetic Resins as Moulding Sands Binders

2016 ◽  
Vol 16 (4) ◽  
pp. 75-78
Author(s):  
K. Major-Gabryś ◽  
A. Grabarczyk ◽  
St.M. Dobosz
Keyword(s):  
Thermal Deformation ◽  
Room Temperature ◽  
Bending Strength ◽  
Deformation Curve ◽  
Biodegradable Material ◽  
Technological Properties ◽  
Foundry Industry ◽  
Environmental Requirements ◽  
New Challenges ◽  
The Impact

Abstract Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials as binders. However, not only environmental requirements grow but also those related to the technological properties of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands. Low elasticity may cause defects during assembly of cores or moulds by the manipulators. The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of self-hardening moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and increases their flexibility at room temperature.

scholarly journals Particle Impact Tests of Ceramic Gas Turbine Materials at Room Temperature

1996 ◽  
Author(s):  
Yasushi Hara ◽  
Keisuke Makino ◽  
Kenichi Mizuno ◽  
Toru Shimamori ◽  
Hiro Yoshida
Keyword(s):  
Impact Strength ◽  
Gas Turbines ◽  
Room Temperature ◽  
Bending Strength ◽  
Empirical Relationship ◽  
Rear Surface ◽  
Particle Impact ◽  
Threshold Velocity ◽  
Impact Tests ◽  
The Impact

In developing ceramic gas turbines (CGT), evaluation of impact strength of ceramic materials is one of the most important subjects. For the purpose of evaluating impact strength of ceramics, particle impact tests of ceramics are carried out at room temperature by using electrothermal (ET) gun and micro-sabot system. Power turbine nozzles and circular disk specimens made of three kinds of Si3N4 are impacted by samarium - cobalt (Sm - Co) magnet flyer particles in vacuum. Weight of particles is fixed to 4mg and particle velocities range from 300 to 900 m/sec. Thickness of specimens are 1.0, 1.5 and 2.0 mm. In this study critical impact velocity, Vc, is defined as threshold velocity which causes visible cracks on the rear surface of the impact side. The cracks seem to be brought by flexural fracture mode. It is found that Vc is related with bending strength, σ, and thickness, t, of the target material as : Vc = C · σ5/6 · t5/3. It is found that impact results with and without rear cracks are well categorized based on this empirical relationship.

Study on Mechanical Properties of PP Modified by β Nucleating Agent under the Low Temperature

2013 ◽  
Vol 710 ◽  
pp. 97-101
Author(s):  
Jiang Zhu ◽  
Xiang Liu ◽  
Qiang Xu ◽  
Liang Cao
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Room Temperature ◽  
Bending Strength ◽  
Nucleating Agent ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
X Ray ◽  
The Impact

The ethylene-propylene polymer (PP) was modified by using a rare earth β-nucleating agent (WBG-II). The crystallization characteristics of PP induced by WBG-II were investigated through the wide-angle X-ray diffraction (WAXD). The effect of β-nucleating agent on the mechanical property of PP under low temperature was also researched. The results confirmed that β-nucleating agent WBG-II can change the crystal structure of PP and induce the β-form crystals in the PP to develop. Moreover, under the room temperature, with the increment of WBG-II, the tensile strength, bending strength and modulus of the modified PP increase, but the impact strength and elongation at break decrease; and especially at-10 °C, this tendency is more obvious.

scholarly journals ANALISIS TADBIR URUS MAJLIS PERBANDARAN JASIN: IMPLIKASINYA TERHADAP KUALITI HIDUP PENDUDUK DARI PERSPEKTIF MAQĀṢID AL-SHARĪ‘AH

2021 ◽  
Vol 29 (2) ◽  
pp. 285-314
Author(s):  
Muhammad Hafiz Ibrahim ◽  
Mohamad Zaidi Abdul Rahman ◽  
Osman Md Rasip
Keyword(s):  
Quality Of Life ◽  
Qualitative Method ◽  
Good Condition ◽  
Municipal Council ◽  
Housing Environment ◽  
Quality Of Life Index ◽  
Administrative Area ◽  
And Performance ◽  
The Impact

Governance is an important thing for Local Authority to ensure resident’s life in good condition at their administration area. In this study, the Researcher used the quality measure of life from the Malaysian Quality of Life Index 2011 such as housing, environment, health, safety and transportation & communication to explore the impact of local government’s administration on quality of life. The objective of this study is to detect the existence of elements of Maqāṣid al-Sharī‘ah in the quality of life governance of Jasin Municipal Council, to study how the Jasin Municipal Council manage the quality of life of residents under its jurisdiction and to know the extent of Jasin Municipal Council on the issue of quality of life. this study uses a fully qualitative method through the analysis of interviews, documents and observations. Overall, this study shows that the quality and performance of Jasin Municipal Council’s services can affect the quality of life population in its administrative area. Beside that, this study also shows Maqāṣid al-Sharī‘ah should be given a priority on each of their action because Maqāṣid al-Sharī‘ah is an objective to better of life.

The Impact of Property Characteristics on Economic Performance of Russian Industrial Enterprises

2005 ◽  
pp. 53-68 ◽  
Author(s):  
R. Kapeliushnikov ◽  
N. Demina
Keyword(s):  
Detailed Analysis ◽  
Economic Performance ◽  
Ownership Concentration ◽  
Corporate Sector ◽  
Concentrated Ownership ◽  
Industrial Enterprises ◽  
Russian Industry ◽  
Control Premium ◽  
And Performance ◽  
The Impact

The paper provides new survey evidence on effects of concentrated ownership upon investment and performance in Russian industrial enterprises. Authors trace major changes in their ownership profile, assess pace of post-privatization redistribution of shareholdings and provide evidence on ownership concentration in the Russian industry. The major econometric findings are that the first largest shareholding is negatively associated with the firm’s investment and performance but surprisingly the second largest shareholding is positively associated with them. Moreover, these relationships do not depend on identity of majority shareholders. These results are consistent with the assumption that the entrenched controlling owners are engaged in extracting "control premium" but sizable shareholdings accumulated by other blockholders may put brakes on their expropriating behavior and thus be conductive for efficiency enhancing. The most interesting topic for further more detailed analysis is formation, stability and roles of coalitions of large blockholders in the corporate sector of post-socialist countries.

The Impact of Women’s Employment on Marital Stability in Qatar Society

2019 ◽  
Vol 10 (2) ◽  
pp. 144-151
Author(s):  
Noora Ahmed Lari ◽  
Keyword(s):  
Work Motivation ◽  
Marital Stability ◽  
Female Employment ◽  
Social Constraints ◽  
Primary Data ◽  
Family Policies ◽  
Insufficient Time ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The State of Qatar has implemented several family policies in order to improve the wellbeing of Qatari families and ensure fair distribution of development benefits for both men and women. However, there is a linkage between female employment outside the home and instability in the marriages of Qatari families. This paper investigates the impact of female employment on marital stability, based on the results of primary data collected in Qatar, a questionnaire that consisted of several sections such as challenges in the workplace, supervisor, family and spouse relations, work motivation and performance. Of the 824 questionnaires that were returned, 807 were completed and valid for analysis. Regression analysis and an ANOVA test have been used to test the relationship between the variables. The results of the research have produced mixed findings about how wives’ employment increases marital instability and have yielded few significant differences on mean scores of discuss on work demands, insufficient time together, housework, financial matters, communication, relatives and rearing children. The results indicates that in general Qatar working women face several challenges in relation to their marital life as part of cultural and social constraints.

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