PVC and PVC-VAc Nanocomposites: Negative Effects on Thermal Stability

Author(s):  
Marco Zanetti ◽  
Simona Valesella ◽  
Maria Paola Luda ◽  
Luigi Costa
2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Sergio Arias Quintero ◽  
Joshua Schmitt ◽  
Richard Blair ◽  
Jayanta Kapat

Historically, gas turbine fuels have been procured based on availability and low cost criteria. However,in the past few decades, with the growing concern over the negative environmental impacts produced by emissions, alternative fuels have been developed and tested under the objective of reducing such negative effects. The physical properties and broad chemical composition of fuels, including trace elements, may result in engine performance issues found only after extensive operation. This, in turn, results in higher maintenance and operation costs. This paper studies the feasibility of several renewable fuels for microturbine application, identifying key relationships between the physical and chemical properties, thermal stability, materials compatibility, and turbine performance.


2019 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
Chenchen Shen ◽  
Rui Li ◽  
Jianzhong Pei ◽  
Jun Cai ◽  
Tao Liu ◽  
...  

To solve the nanoparticles (NPs) agglomeration phenomena of nanometer calcium carbonate (nano-CaCO3) modified asphalt binder, in this paper, solvent-free CaCO3 nanofluids (NFs) were prepared based on surface-functionalized CaCO3 NPs to study the effect on asphalt. Microscopic structures, compositions, and thermal stability were characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), transmission electron microscope (TEM), and thermogravimetric analyzer (TGA), respectively. Results showed that perfect CaCO3 NFs were successfully prepared, and were good enough for asphalt mixing due to their excellent thermal stability. Scanning electron microscopy (SEM), conventional tests, dynamic shear rheometry (DSR), and bending beam rheometry (BBR) were conducted to investigate the modifying effect. The SEM results indicated that CaCO3 NFs had better compatibility with asphalt binder than original CaCO3 NPs. Conventional and DSR test results demonstrated that CaCO3 NFs had slight negative effects on high-temperature performance while improving the low-temperature performance of the asphalt binder. The BBR test results confirmed that the modifier addition effectively enhanced asphalt binders’ low-temperature crack resistance performance.


Author(s):  
S. Arias Quintero ◽  
J. Schmitt ◽  
R. Blair ◽  
J. Kapat

Historically, gas turbine fuels have been procured based on availability and low cost criteria. But in the last few decades, with the growing concern over the negative environmental impacts produced by emissions, alternative fuels have been developed and tested with the objective to reduce such negative effects. Physical properties and the broad chemical composition, including trace elements, may result in engine performance issues found only after extensive operation. This, in turn, results in higher maintenance and operation costs. This paper studies the feasibility for microturbine application of several renewable fuels, identifying key relationships between physical and chemical properties, thermal stability, materials compatibility, and turbine performance.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.


Author(s):  
J. Liu ◽  
N. D. Theodore ◽  
D. Adams ◽  
S. Russell ◽  
T. L. Alford ◽  
...  

Copper-based metallization has recently attracted extensive research because of its potential application in ultra-large-scale integration (ULSI) of semiconductor devices. The feasibility of copper metallization is, however, limited due to its thermal stability issues. In order to utilize copper in metallization systems diffusion barriers such as titanium nitride and other refractory materials, have been employed to enhance the thermal stability of copper. Titanium nitride layers can be formed by annealing Cu(Ti) alloy film evaporated on thermally grown SiO2 substrates in an ammonia ambient. We report here the microstructural evolution of Cu(Ti)/SiO2 layers during annealing in NH3 flowing ambient.The Cu(Ti) films used in this experiment were prepared by electron beam evaporation onto thermally grown SiO2 substrates. The nominal composition of the Cu(Ti) alloy was Cu73Ti27. Thermal treatments were conducted in NH3 flowing ambient for 30 minutes at temperatures ranging from 450°C to 650°C. Cross-section TEM specimens were prepared by the standard procedure.


2020 ◽  
Author(s):  
Feng Xiao ◽  
Bin Yao ◽  
Pavankumar Challa Sasi ◽  
Svetlana Golovko ◽  
Dana Soli ◽  
...  

2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.


Crisis ◽  
2013 ◽  
Vol 34 (5) ◽  
pp. 348-353 ◽  
Author(s):  
Hajime Sueki

Background: Previous studies have shown that suicide-related Internet use can have both negative and positive psychological effects. Aims: This study examined the effect of suicide-related Internet use on users’ suicidal ideation, depression/anxiety tendency, and loneliness. Method: A two-wave panel study of 850 Internet users was conducted via the Internet. Results: Suicide-related Internet use (e.g., browsing websites about suicide methods) had negative effects on suicidal ideation and depression/anxiety tendency. No forms of suicide-related Internet use, even those that would generally be considered positive, were found to decrease users’ suicidal ideation. In addition, our results suggest that the greater the suicidal ideation and feelings of depression and loneliness of Internet users, the more they used the Internet. Conclusion: Since suicide-related Internet use can adversely influence the mental health of young adults, it is necessary to take measures to reduce their exposure to such information.


Crisis ◽  
2020 ◽  
pp. 1-8
Author(s):  
Christian Ulrich Eriksen ◽  
Flemming Konradsen ◽  
Thilde Vildekilde

Abstract. Background: Information on methods of suicide is available online, and access to information on methods of suicide appears to contribute to a small but significant proportion of suicides. There is limited documentation of how methods of suicide are being profiled, as well as what content exists in other languages than English. Aim: We aimed to analyze and compare how methods of suicide are profiled on Danish and English-language websites. Method: We applied a categorization and content analysis of websites describing methods of suicide. Sites were retrieved by applying widely used Danish and English-language search terms. Results: A total of 136 English-language websites and 106 Danish-language websites were included for analysis. Websites were more often categorized as prevention or support sites, academic or policy sites, and against suicide sites than dedicated suicide sites (i.e., pro-suicide sites), or information sites. However, information on methods of suicide was available, and 20.1% and 8.9% of the English and Danish-language sites, respectively, suggested that a particular method of suicide was quick, easy, painless, or certain to result in death. Limitations: Only one author coded and analyzed all websites. A further operationalization of the content analysis checklist is warranted to increase reliability. Conclusion: The websites primarily had a prevention or anti-suicide focus, but information on methods of suicide was available, requiring an increased focus on how to diminish the negative effects of harmful online content.


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