This paper presents the results of field and numerical studies on the soil thermal response around a field-scale energy pile. The investigation focuses on the effect of monotonic heating, monotonic ...cooling, and daily cyclic heating/cooling of the energy pile on the soil thermal response. The soil temperature changes are found to be highest near the edge of the energy pile and reduce with increasing radial distance for all operating modes. The cyclic temperature changes of the energy pile impose lower ground temperature changes compared to monotonic temperature changes due to frequent ground thermal recoveries during each thermal cycle. The soil zone experiencing radial thermal influence is also smaller for cyclic temperature changes of the energy pile. The results generally indicate that cyclic heating/cooling of the energy pile will improve geothermal energy utilization with lower thermal impacts on the ground for long term operations of ground source heat pumps.
Abstract Objectives: (1) Primary objective: To study the selected risk factors and clinical and radiological profiles of patients admitted with mucormycosis. (2) Secondary objective: To study the ...treatment pattern of patients admitted with mucormycosis. Materials and Methods: A descriptive cross-sectional study was conducted, which included the data of all patients admitted with the histopathological diagnosis of mucormycosis after undergoing surgery in the Otorhinolaryngology Department, Government Medical College, Thrissur, from January 2020 to September 2021. The risk factors, clinical and radiological profiles along with the treatment pattern of patients admitted with mucormycosis were analyzed. Results: Most of the cases belonged to the 40–50 age group, although the mean age was 52.24 with patients ranging from the age of 32–76. The male: female ratio was 2:1. All patients had diabetes mellitus. 89.7% had hypertension, and 76.9% had chronic kidney disease. Conclusion: Diabetes mellitus and COVID-19 cause a predilection for mucor to invade the paranasal sinuses and beyond. Aggressive treatment with amphotericin B along with surgical clearance aided by radiological investigation will help in decreasing the morbidity of the disease.
This paper examines the thermal resistances of energy piles and surrounding soils. A field-scale bored energy pile was installed through stiff sandy clay and dense sand and instrumented to measure ...temperatures on the external walls of the heat exchanger pipes, at the pile-soil interface, and in the soil. The radial temperature gradients between the pipes and the pile-soil interface, and the pile-soil interface and the soil, were used to evaluate the pile and soil thermal resistances, respectively. The thermal resistances were on the same order of magnitude with values of 0.053 mK/W, 0.072 mK/W, and 0.066 mK/W for the pile, stiff sandy clay, and dense sand due to similarities in their thermal properties. The analysis suggests that pile and soil thermal resistances are influenced by the pile dimensions, number of pipes, concrete cover, soil type and duration of heating. Hence, meticulous interpretation of thermal resistances considering these parameters should be conducted to understand heat transfer processes in energy piles accurately. Estimates of the pile thermal resistance from the equivalent diameter and thermal response test methods were found to be inconsistent with each other, highlighting the significance of considering steady state in-situ radial temperature gradients in designing energy pile systems.
An overview of the most important development stages of floating point absorber wave energy converters is presented. At a given location, the wave energy resource has to be first assessed for varying ...seasons. The mechanisms used to convert wave energy to usable energy vary for different wave energy conversion systems. The power output of the generator will have variations due to varying incident waves. The wave structure-interaction leads to modifications in the incident waves; thus, the power output is also affected. The device has to be stable enough to prevent itself from capsizing. The point absorber will give optimum performance when the incident wave frequencies correspond to the natural frequency of the device. The methods for calculating natural frequencies for pitching and heaving systems are presented. Mooring systems maintain the point absorber at the desired location. Various mooring configurations as well as the most commonly used materials for mooring lines are discussed. An overview of scaled modelling is also presented.
The Earth and the oceans have a natural temperature gradient between the surface and given depths. The natural temperature gradient is used to operate renewable energy systems, such as power ...generation and space heating/cooling, which operate on similar thermodynamic concepts. For a given purpose, different technologies are used to extract heat from the two resources. Even though the concepts of the two systems are the same, their energy extracting performance is different. An overview of the similarities between the usages of the two thermal resources is presented in this paper. The energy balances at the surface of the Earth and the oceans, system performances, availabilities and economics are also presented.
Lifestyle, illness and treatment factors in people with bipolar disorder (BD) may
confer additional risk of morbidity and mortality to the increasing rates of
obesity, metabolic syndrome, diabetes ...mellitus and cardiovascular mortality in the
general population.The aim of this review is to examine whether the risk of obesity and related
morbidity and mortality are raised in BD, and possible contributory effects of
lifestyle, illness and treatment factors to this risk.Systematic search of Medline and Cochrane Collaboration for relevant studies followed
by a critical review of literature was carried out.Mortality from cardiovascular causes and pulmonary embolism (standardized mortality
ratio approximately 2.0), and morbidity from obesity and type 2 diabetes mellitus
may be increased in BD compared to the general population. Reduced exercise and poor
diet, frequent depressive episodes, comorbidity with substance misuse and poor
quality general medical care contribute to the additional risk of these medical
problems in people with BD. There is no evidence that patients with BD are more
sensitive than other patients to weight gain and medical problems associated with
long-term use of psychotropic medication; in fact long-term treatment with lithium,
antipsychotics and tricyclic antidepressants may reduce overall mortality.Psychiatrists, general practitioners and other health professionals should work
together to systematically assess and manage weight gain and related medical
problems to reduce the morbidity and mortality associated with obesity in BD. There
is insufficient evidence to associate any of these factors with specific drug
treatments. More research is required to understand how BD changes the risk for
physical health comorbidity.
Geothermal energy piles utilize the almost constant ground temperature at shallow depths below the ground surface to heat and/or cool built structures. Heat is extracted from and/or injected into the ...ground through the use of a heat carrier fluid that flows in pipes attached to the reinforcement cage of the pile foundations. The performance of the energy piles can be improved by enhancing the heat exchange between the heat carrier fluid and the ground. The purpose of this paper is to provide evidence from literature on multidisciplinary methods to improve the thermal properties of elements in a geothermal energy pile. Geometrical optimization such as the number of pipes and their arrangement can be done to reduce the total pile thermal resistance. Nanofluids can be used as the heat carrier fluid to enhance the fluid conductive and convective heat transfer. Highly thermally conductive fillers can be mixed with the pipe material to enhance its thermal conductivity. The thermal properties of the concrete can also be enhanced by adding highly thermo-conductive materials to the concrete mix.
AbstractThe axial and radial thermal responses of a field-scale energy pile installed in dense sand and subjected to monotonic and cyclic temperatures are examined. It is found that the axial thermal ...strains in the pile are more restricted to thermal expansion/contraction compared to radial thermal strains. The radial thermal strains are close to that of a pile expanding/contracting freely, indicating minimal resistance from the surrounding soil in the radial direction. As a result, very low magnitudes of radial thermal stresses developed in the pile compared to axial thermal stresses. The pile–soil radial contact stresses estimated from the cavity expansion analysis are up to 12 kPa for a pile temperature change of 22.5°C and are likely to stay low for the range of commonly encountered operating temperatures for cast-in-place concrete energy piles installed in dense sand. During cyclic heating and cooling, unstable changes in axial and radial thermal strains were observed initially during initial cycles, indicating a ratcheting response. The changes in strains became more stable over further cycles without significant changes in side friction or pile–soil contact stresses.
PDF
