797 research outputs found

    WHAT ARE THE CULTURAL VALUES OF A CASE OF ASIAN HIGH-ACHIEVING HIGH SCHOOL STUDENTS?

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    We always want to improve education. We look to other countries and see that the people of Asian countries consistently perform well in school and honor knowledge and education. How can we improve education if we do not understand how the “best” students study and perform

    Thermal Properties of Soft Nanomaterials: Thermal Measurement Design

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    Soft materials like hydrogels have multiple tunable material properties because of their unique structures. Due to the ability to respond to stimuli like temperature or chemical environment, they have numerous applications in different fields like delivering drugs inside the human body and other medical uses. Details of the thermal transport mechanisms, as well as the overall thermal properties, are critical for a variety of applications. Multi-property measurements elucidate the underlying transport mechanisms in the soft materials. This research demonstrates a new methodology of measuring thermal properties of soft materials. This work uses the 3w method [1,2] for measuring the thermal conductivity of soft hydrogels. In the 3w method, heat is generated in thin heater line excited by a sinusoidal current at a frequency of w. We measure the voltage response at the third harmonic of the input frequency (3w). This response is related to the temperature rise and thus the thermal properties. Once the measurement technique is optimized, PVA-PVP hydrogels are tested. Using a 2D mathematical model of the heat transfer, the thermal conductivities of soft material are calculated from the experimental data. Based on the methodology built during this research, this technique is available now for other soft materials beyond hydrogels and the precision of this methodology can be improved by further studies

    Inequalities in Infertility Service Utilization: A Comparison of Latina and Caucasian Women with Impaired Fecundity Who Seek and Do Not Seek Care

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    Purpose: To compare racial differences in accessing infertility services, and to characterize socioeconomic, cultural and social factors that influence the propensity to seek care. Materials and Methods: Using data from the 2002 and 2006-2010 rounds of the National Survey of Family Growth, bivariate analyses and multiple logistic regressions were performed to determine the associations between individual patient characteristics and health seeking practices, stratified by ethnicity. Results: Factors that were significantly associated with seeking infertility services included Latina ethnicity, age, country of birth, more than high school education, being born in the United States, placing importance on religion, \u3e200% federal poverty level, not having medical insurance for the past 12 months, and stating “Yes” to the question “Do you want a baby?”. Conclusions: Latinas are more likely to seek infertility services compared with Caucasian women. A number of demographic, cultural, social, and socioeconomic factors are significantly related to propensity to seek infertility care. This study shows that infertility service utilization is a multifaceted issue and further qualitative research is needed to better understand factors contributing to service utilization. Keywords: Infertility; Access to care; Health disparity; Inequalitie

    Thermal Properties of Soft Nanomaterials: Materials Synthesis and Fabrication

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    The properties of soft nanomaterials are hard to measure exactly due to their mechanical properties and unstable shape. In particular, hydrogels are a class of cross-linked polymers that can absorb large quantities of water changing their shape under the influence of various conditions such as humidity, temperature, and pH. This research addresses the fabrication of a material that has a significant contrast in properties under different conditions (e.g. temperature, wetting, and pH) and determine the physical mechanisms of heat transfer in this nanomaterial. The hydrogels are made using a several cycles of a freeze-thaw method. The method requires soluble material. We set the solution in chamber slide which give us a rectangular shape. We freeze the sample under -20 ̊ C for 21 hours and thaw at room temperature for 3 hours. The 3ω method measures the thermal conductivity of the soft nanomaterials including a polyvinyl alcohol (PVA) – polyvinyl pyrrolidone (PVP) hydrogel and a PVA-Dimethyl sulfoxide(DMSO) hydrogel. By analyzing the magnitude and the phase of the temperature response to a heating signal, we determine the thermal conductivity of each material. To enhance the thermal transport, these materials are embedded with gold nanoparticles. By comparing experimental value with theoretical value, we conclude fabrication methods have a significant impact upon the material properties. Further research will be focusing on different soft nanomaterials and include the impact of the nanoparticle concentration and hydrogel fabrication methods

    Geostatistical and stochastic study of flow and tracer transport in the unsaturated zone at Yucca Mountain

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    Yucca Mountain has been proposed by the U.S. Department of Energy as the nation’s long-term, permanent geologic repository for spent nuclear fuel or high-level radioactive waste. The potential repository would be located in Yucca Mountain’s unsaturated zone (UZ), which acts as a critical natural barrier delaying arrival of radionuclides to the water table. Since radionuclide transport in groundwater can pose serious threats to human health and the environment, it is important to understand how much and how fast water and radionuclides travel through the UZ to groundwater. The UZ system consists of multiple hydrogeologic units whose hydraulic and geochemical properties exhibit systematic and random spatial variation, or heterogeneity, at multiple scales. Predictions of radionuclide transport under such complicated conditions are uncertain, and the uncertainty complicates decision making and risk analysis. This project aims at using geostatistical and stochastic methods to assess uncertainty of unsaturated flow and radionuclide transport in the UZ at Yucca Mountain. Focus of this study is parameter uncertainty of hydraulic and transport properties of the UZ. The parametric uncertainty arises since limited parameter measurements are unable to deterministically describe spatial variability of the parameters. In this project, matrix porosity, permeability and sorption coefficient of the reactive tracer (neptunium) of the UZ are treated as random variables. Corresponding propagation of parametric uncertainty is quantitatively measured using mean, variance, 5th and 95th percentiles of simulated state variables (e.g., saturation, capillary pressure, percolation flux, and travel time). These statistics are evaluated using a Monte Carlo method, in which a three-dimensional flow and transport model implemented using the TOUGH2 code is executed with multiple parameter realizations of the random model parameters

    Identification and differential regional expression of KOR-3/ORL-1 gene splice variants in mouse brain

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    AbstractKOR-3, also known as ORL-1, is a member of the opioid receptor family, encoding the murine receptor for orphanin FQ/nociceptin. In the current studies we have identified five different splice variants of KOR-3 in mouse brain, three of which have not been previously reported. In addition to variants with a 15 bp deletion at the 3′-end of the first coding exon (KOR-3d) and an 81 bp insertion between the second and third coding exons (KOR-3e), three new variants with insertions of 34 (KOR-3a), 98 (KOR-3b), and 139 bp (KOR-3c) between the first and second coding exons have been obtained. The expression of the three variants in mouse brain varies markedly among brain regions with a distribution which is quite distinct from KOR-3 itself. Of greatest interest was the presence of high levels of KOR-3a in the striatum, a region with no demonstrable KOR-3, and in the cortex. KOR-3c was seen in the periaqueductal gray and hypothalamus, regions where KOR-3 predominated. The brainstem had similar levels of KOR-3, KOR-3a, and KOR-3d. In contrast, KOR-3d was most prominent in the cerebellum. KOR-3b levels were very low throughout
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