Acetylene terminated matrix resins

The synthesis of resins with terminal acetylene groups has provided a promising technology to yield high performance structural materials. Because these resins cure through an addition reaction, no volatile by-products are produced during the processing. The cured products have high thermal stability and good properties retention after exposure to humidity. Resins with a wide variety of different chemical structures between the terminal acetylene groups are synthesized and their mechanical properties studied. The ability of the acetylene cured polymers to give good mechanical properties is demonstrated by the resins with quinoxaline structures. Processibility of these resins can be manipulated by varying the chain length between the acetylene groups or by blending in different amounts of reactive deluents. Processing conditions similar to the state-of-the-art epoxy can be attained by using backbone structures like ether-sulfone or bis-phenol-A. The wide range of mechanical properties and processing conditions attainable by this class of resins should allow them to be used in a wide variety of applications

Social participation and quality of life in community-dwelling older adults through the Lifestyle Redesign® program

poster abstractPurpose. The purpose of this study was to evaluate the effect of exercise and Lifestyle Redesign® on social participation and quality of life in community-dwelling older adults. Methods. Twelve community-dwelling adults aged 65 years and older were recruited to participate in the study. The study took place at a senior center located in central Indiana, where activities were provided for low-income seniors from nearby neighborhoods. This study was a mixed methods design study. Ten week occupation-based group activities from the Lifestyle Redesign® program were implemented as intervention. An exercise program was provided on the same days to the same participants as its own control. The order of exercise and intervention was alternated every other week to decrease rater bias. Activities included in the exercise program were line dancing, chair aerobics, yoga, etc. Social participation was measured using the Social Profile at the end of each exercise and intervention session as repeated measures. The inter-rater reliability of the Social Profile was confirmed at the alpha level of 0.84 for its use in the older adult population. Researchers of the study established inter-rater item agreement prior to the start of the study by observing a recorded group activity and independently rated the group. The researchers then compared scores, discussed discrepancies, and came to a consensus on scores. Five group levels are included in the tool: parallel, associative, basic cooperative, supportive cooperative, and mature levels. The researchers averaged the scores of each level within each subscale: activity participation, social interaction, and group membership and roles. Quantitative data was analyzed using descriptive and inferential statistical procedures. Quality of life was explored through semistructured interviews, and then analyzed using thematic analysis. Results. The SPSS version 16.0 was used for quantitative data analyses. The Spearman’s Rank Correlation Coefficient was used for inter-rater agreements. The results indicated moderately high to very high inter-rater agreements in both programs. The Wilcoxon signed-ranks test results indicated statistically significant differences in social participation between the two programs for parallel, basic cooperative, supportive cooperative, and mature levels. However, statistically significant difference for associate/project level was not found. Shapiro Wilks test for normality was conducted to check for normal distributions of the data. Results indicated normal distributions on parallel, associate/project, basic cooperative, and supportive cooperative levels for both programs, therefore, paired sample t-tests were performed. Results showed statistically significant differences in social participation between the two programs for parallel, basic cooperative, and supportive cooperative levels. Overall, the quantitative results showed higher levels of social participation in intervention than in exercise program. Three main themes emerged that supported participants’ quality of life were well-being, peace of mind, and relationships. Five aspects that negatively affected quality of life were loss of a spouse, money, loneliness, a decrease in physical health, and family illness. Conclusion. The results from the study support the positive effect of occupation-based programming on social participation in community-dwelling older adults. In achieving good quality of life while aging, it is important to maintain relationships with family and friends, and finding time to support and help others in need

Multifunctional amorphous metal oxide thin films – Structure transformation for various functions

Metal oxides are well-known high-k dielectric materials since the early solid state electronics age. However, they were rarely used in modern IC chips except as charge storage layers in MOS capacitors. Recently, due to the performance and reliability issues of the nm thick SiO2 in the gate dielectric application, metal oxide high-k dielectrics become popular alternatives. For the most advanced MOSFET, the sub nm EOT metal oxide is the preferred choice for the gate dielectric for its low leakage current and high reliability. Separately, metal oxides, such as IGZO or ZnO, are popular semiconductor materials in thin film transistors (TFTs) because of its high field effect mobility, e.g., 10 to 100 times that of the a-Si:H TFT. For above applications, the crystalline structure is preferable. For example, for the same metal oxide dielectric, the k value of the crystalline film can be several times higher than that of the amorphous film. TFTs made of the crystalline ZnO semiconductor film have much higher mobilities than those made of the amorphous ZnO semiconductor film. However, for practical applications, only amorphous films are used in products considering the repeatability, reliability, and manufacturability factors. In this paper, the author will discuss the versatility of the amorphous metal oxide high-k thin film through transformation of the structure in simple process steps. For example, the sputter deposited zirconium doped hafnium oxide (ZrHfO) high-k dielectric can be made into the sub 1 nm EOT gate dielectric on Si wafer. By inserting a very thin metal, semiconductor, or dielectric layer in the ZrHfO film during the sputtering process and subsequently annealed with a RTP step, a nanocrystal-embedded dielectric structure is formed, which is a nonvolatile memory device. Each nanocrystal can store a single electron. Even holes can be stored in this kind of device once the proper nanocrystal material is chosen. Furthermore, nano resistors can be formed in the high-k film after a dielectric breakdown step. In the low voltage operation range, the new structure performs like a diode except the current increases linearly not exponentially with the applied voltage. The nano resistor structure can emit light under the high voltage stress condition, which is called the solid state incandescent LED (SSI-LED). The light emission phenomenon can last for more than 20,000 hours in air without failure. Among many possible applications, the SSI-LED can be used to fabricate the on-chip optical interconnect. 1. Y. Kuo, invited, “Nanocrystals Embedded High-k Nonvolatile Memories – bulk film and nanocrystal material effects,” ECS Trans., 53(4), 121-128 (2013). 2. Y. Kuo, “A Solid State Thin Film Incandescent Light Emitting Device,” IEEE Trans. Elec. Dev., 62(11), 3536-3540 (2015). 3. Y. Kuo, “A new type of solid state incandescent LED (SSI-LED) prepared by sputter deposited metal oxide thin film on Si wafer,” 13th ISSP Proc., 20-24 (2015). 4. Y. Kuo, “A Metal Oxide Antifuse-Diode Device,” ECS Trans. Low-Dimensional Nanoscale Electronic and Photonic Devices 8, 69(12) 23-29 (2015

Quantum-Fluctuation-Initiated Coherence in Multi-Octave Raman Optical Frequency Combs

We show experimentally and theoretically that the spectral components of a multi-octave frequency comb spontaneously created by stimulated Raman scattering in a hydrogen-filled hollow-core photonic crystal fiber exhibit strong self coherence and mutual coherence within each 12 ns driving laser pulse. This coherence arises in spite of the field's initiation being from quantum zero-point fluctuations, which causes each spectral component to show large phase and energy fluctuations. This points to the possibility of an optical frequency comb with nonclassical correlations between all comb lines.Comment: Accepted for publication, Physical Review Letters, 201

Arbitrage opportunities and feedback trading in emissions and energy markets

This paper extends Sentana and Wadhwani (SW 1992) model to study the presence of feedback trading in emissions and energy markets and the extent to which such behaviour is linked to the level of arbitrage opportunities. Applying our augmented models to the carbon emission and major energy markets in Europe, we find evidence of feedback trading in coal and electricity markets, but not in carbon market where the institutional investors dominate. This finding is consistent with the notion that institutional investors are less susceptible to pursuing feedback-style investment strategies. In further analysis, our results show that the intensity of feedback trading is significantly related to the level of arbitrage opportunities, and that the significance of such relationship depends on the market regimes

Multi-scale analysis of timber framed structures filled with earth and stones

This paper deals with the seismic analysis of timber framed houses filled by stones and earth mortar using a multi-scale approach going from the cell to the wall and then to the house. At the scale of the elementary cells, experimental results allow fitting the parameters of a new versatile hysteretic law presented herein through the definition of a macro-element. Then, at the scale of wall, the numerical simulations are able to predict its behavior under quasi-static cyclic loading and is compared to experimental results allowing validating the macro-element model