Browsing by Subject "temperature"

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    Increased Ischemic Cardiac Deaths in Central Indiana in Summer Months Compared to Winter Months
    (Office of the Vice Chancellor for Research, 2013-04-05) Cook, Shannon; Lloyd, Frank, Jr.; Ballew, Alfie; Sandusky, George E.
    Cardiovascular diseases have been the leading cause of death in the United States for several decades. Despite sustained declines in the mortality rates from these diseases, the magnitude of the disease is still staggering. One large recent study, using data on hundreds of heart attacks documented in the National Registry of Myocardial Infarction, found that 53 percent more cases in winter than in summer. The primary culprit, many believe, is temperature. Cold weather narrows coronary arteries and raises blood pressure, stressing the heart. Physical strain and ruptured plaques caused by shoveling snow are also commonly cited. But in a recent study, two researchers, found that the risk increases even in warm climates. Analyzing death certificates in seven regions with different climates, Los Angeles, Texas, Arizona, Pennsylvania, Massachusetts and others found that cardiovascular deaths rose up to 36 percent between summer and winter, regardless of climate and temperatures In this study we evaluated the incidence of ischemic cardiomyopathy in the Central Indiana area in the winter months compared to the summer months for the years 1998 to 2002. Approximately 5325 deaths were seen in the Marion County Morgue in central Indiana in this time period. There were 609 ischemic cardiac deaths seen in the summer (March 15th through October 15th) compared to 434 ischemic cardiac deaths seen in the winter (October 15th through March 15th). The deaths by years in the summer were 129, 131, 92, 127, and 130 and in the winter were 95, 96, 90, 96, and 57 respectively. In conclusion, this study was consistent with the outcome as the previous study done in multiple northern and southern cities in the country.
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    Temperature-dependent mechanical properties of Tin+1CnO2 (n = 1, 2) MXene monolayers: a first-principles study
    (RSC, 2020-02) Khaledialidusti, Rasoul; Anasori, Babak; Barnoush, Afrooz; Mechanical and Energy Engineering, School of Engineering and Technology
    Two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides (named as MXenes) have become of the fastest growing family of 2D materials in terms of compositions and their applications in different areas. One of the least explored properties of MXenes is their mechanical properties. While the basic elastic properties of MXenes have been studied by first-principles, the effects of temperature on the elastic properties have never been explored. In this study, we investigate temperature-dependent structural and mechanical properties of the titanium-containing MXenes (Tin+1CnO2 (n = 1, 2)) based on the first-principles calculations combined with quasi-harmonic approximation. The effective Young's modulus of a single layer of Ti2CO2 and Ti3C2O2 is calculated to be 565 and 482 GPa, respectively, at 0 K. By increasing temperature to 1000 K, Young's moduli of Ti2CO2 and Ti3C2O2 decrease to 469 GPa and 442 GPa, respectively, which indicates a larger reduction in stiffness in thinner MXenes at higher temperatures. Our calculations of the temperature-dependent bond strengths within MXenes showed that titanium and carbon atoms in Ti3C2O2 form stronger bonds than Ti2CO2 and atomic bonds in Ti2CO2 lose their stiffness more than Ti3C2O2 with increasing temperatures. The Debye temperature of these monolayers is also calculated to provide a comparison of the thermal conductivity between these monolayers, in which the results show that the Ti3C2O2 has a higher thermal conductivity than Ti2CO2. Our calculated electronic properties results of the monolayers are also shown that the electrical conductivity of the monolayers would not change with temperature. Our study extends MXenes applications to high-temperature applications, such as structural composite components and aerospace coatings.
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    Thermal remote sensing for plant ecology from leaf to globe
    (Wiley, 2022-09) Farella, Martha M.; Fisher, Joshua B.; Jiao, Wenzhe; Key, Kesondra B.; Barnes, Mallory L.; School of Public and Environmental Affairs
    1. Surface temperatures are mechanistically linked to vegetation biophysical and physiological processes. Although remote sensing in the thermal infrared (TIR) domain can offer novel insights into the impacts of changing surface temperatures on vegetation, the transformative potential of remote sensing for plant ecology has not yet been realized. 2. Remotely sensed surface temperatures can be used to derive stomatal behaviour and identify stressful environmental conditions in near-real time. Plant species, traits and structural characteristics can be evaluated with high spectral resolution TIR emissivity. 3. Beyond canopy scales, thermal remote sensing can enhance the inferences obtained from manipulative experiments and empirical evidence, providing unique insight into shifts in species ranges and phenology with changing climate conditions. 4. Scaling leaf traits, canopy structure and regional patterns require an integrated understanding of both process and technology. Theory linking surface temperatures to vegetation dynamics is summarized from an energy balance perspective. We outline scaling considerations including the impacts of morphology on leaf energy balance, canopy structure influences on convective heat exchange and potential confounding impacts of non-vegetated surfaces. 5. Synthesis. We introduce a unifying framework to link leaf to globe through thermal remote sensing. Recent and emerging advances in sensors, data availability and analytics, together with synergies between TIR remote sensing and other data sources, present a timely opportunity for ecologists to advance our understanding of plant physiology, ecology and biogeography with thermal remote sensing.