Earth-Coupled Heat Pump Systems--Selection, Design & Performance

Rising energy costs have caused many people to look for more efficient ways to heat and cool their homes. One of the most energy-efficient systems to come along in recent years is the earth-coupled heat pump. Pioneered at the University of Kentucky in the 1950s, the earth-coupled system relies on the thermal capacity of water to transfer heat, whereas conventional heat pump relies on outside air. ln an earth-coupled system, water source heat pump is connected (or coupled ) to pipes in the ground or in wells for the source of heat in winter and cool air in the summer. In this way, heating or cooling energy is transferred by water through the system

Wood Burning and Creosote Buildup

For many years,wood was the prime source of heating the house and continues to be so in some parts of the world. In this country, we are beginning to see many individuals returning to wood burning--using it as an alternate heat source and even occasionally as a primary heat source. Heating with wood, however, is not for everyone. It is not as simple as heating with gas, oil or electricity. It is not as convenient to use because it requires a considerable amount of labor, a large storage area for the wood, more cleaning of the home, many more safety precautions, and acceptance of fluctuating room temperatures. With the development of efficient wood stoves and furnaces, creosote buildup in the chimney became more of a problem because the flue gas temperatures were lower due to more of the heat being put in the room rather than going up the chimney. Creosote clings firmly to the pipe and chimney walls, causing buildup of a very flammable material. When creosote deposits catch fire, the heat is very intense and can result in roof and house fires. Even if the burning creosote does not cause a fire from flying sparks or cracks in the chimney, it tends to weaken the chimney masonry or warp metal chimneys

Kerosene Heaters

Many families are buying supplemental space heating units in an attempt to use heat only where it is needed and thus lower the total heating bill. lf you turn down your central heat thermostat and place such a unit in a room where the family spends most of their waking hours, heating bills may be reduced. Such savings appear to be significant, but each family first needs to carefully consider the safety risks and their energy savings potential as well as the lifestyle changes that might be necessary

Demand Response of HVACs in Large Residential Communities Based on Experimental Developments

Heating, ventilation, and air-conditioning (HVAC) systems contribute the largest electricity usage for a residential community. Modeling of the HVAC systems facilitate the study of demand response (DR) at both the residential and the power system level. In this paper, the equivalent thermal model of a reference house was proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. The aggregated HVAC load was modeled based on the reference house while considering a realistic distribution of HVAC parameters derived from data that was provided by one of the largest smart grid field demonstrators in rural America. A sequential DR as part of a Virtual Power Plant (VPP) control was proposed to reduce both ramping rate and peak power at the aggregated level, while maintaining human comfort according to ASHRAE standard

The Effect of High Efficiency Building Technologies and PV Generation on the Energy Profiles for Typical US Residences

The penetrations of high efficiency technologies and photovoltaic (PV) generation are increasing in the residential sector. Technologies such as improved insulation and efficient HVAC systems significantly affect the energy profile of a house. This effect varies due to climate characteristics, i.e. temperature, solar radiation, relative humidity, and wind speeds. The effect of other technologies, such as efficient water heaters, lighting, or kitchen appliances, is mainly governed by human behavior, which may be represented by a schedule. This paper studies the performance of both climate-influenced and scheduled household devices among different levels of efficiency through combined computational and experimental methods. Three houses were constructed by the Tennessee Valley Authority and were outfitted with robots that mimicked the occupation of a family. The houses represented three categories of residences, namely, typical builder, retrofit, and near net-zero-energy. With the energy and weather data collected from 2009 to 2014, a total of four house energy models were developed to account for equipment changes throughout the years. The studies performed using these models considered the behavior of the HVAC systems, PV system, and water heaters as well as climate effects

Virtual Power Plant Control for Large Residential Communities Using HVAC Systems for Energy Storage

Heating, ventilation, and air-conditioning (HVAC) systems use the most electricity of any household appliance in residential communities. HVAC system modeling facilitates the study of demand response (DR) at both the residential and power system levels. In this article, the equivalent thermal model of a reference house is proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. Energy storage capacity of HVAC systems is calculated and an equivalent state-of-charge is defined. The uniformity between HVAC systems and battery energy storage system is demonstrated by DR control. The aggregated HVAC load model is based on the reference house and considers a realistic distribution of HVAC parameters derived from one of the largest smart grid field demonstrators in rural America. A sequential DR scheme as part of a virtual power plant control is proposed to reduce both ramping rate and peak power at the aggregated level, while maintaining human comfort according to ASHRAE standards

Assessing clinical communication skills in physicians: are the skills context specific or generalizable

<p>Abstract</p> <p>Background</p> <p>Communication skills are essential for physicians to practice Medicine. Evidence for the validity and domain specificity of communication skills in physicians is equivocal and requires further research. This research was conducted to adduce evidence for content and context specificity of communication skills and to assess the usefulness of a generic instrument for assessing communication skills in International Medical Graduates (IMGs).</p> <p>Methods</p> <p>A psychometric design was used for identifying the reliability and validity of the communication skills instruments used for high-stakes exams for IMG's. Data were collected from 39 IMGs (19 men – 48.7%; 20 women – 51.3%; Mean age = 41 years) assessed at 14 station OSCE and subsequently in supervised clinical practice with several instruments (patient surveys; ITERs; Mini-CEX).</p> <p>Results</p> <p>All the instruments had adequate reliability (Cronbach's alpha: .54 – .96). There were significant correlations (r range: 0.37 – 0.70, <it>p </it>< .05) of communication skills assessed by examiner with standardized patients, and of mini-CEX with patient surveys, and ITERs. The intra-item reliability across all cases for the 13 items was low (Cronbach's alpha: .20 – .56). The correlations of communication skills within method (e.g., OSCE or clinical practice) were significant but were non-significant between methods (e.g., OSCE and clinical practice).</p> <p>Conclusion</p> <p>The results provide evidence of context specificity of communication skills, as well as convergent and criterion-related validity of communication skills. Both in OSCEs and clinical practice, communication checklists need to be case specific, designed for content validity.</p

A comparison of course-related stressors in undergraduate problem-based learning (PBL) versus non-PBL medical programmes

Background: Medical students report high levels of stress related to their medical training as well as to other personal and financial factors. The aim of this study is to investigate whether there are differences in course-related stressors reported by medical students on undergraduate problem-based learning (PBL) and non-PBL programmes in the UK. Method: A cross-sectional study of second-year medical students in two UK medical schools (one PBL and one non-PBL programme) was conducted. A 16-question self-report questionnaire, derived from the Perceived Medical Student Stress Scale and the Higher Education Stress Inventory, was used to measure course-related stressors. Following univariate analysis of each stressor between groups, multivariate logistic regression was used to determine which stressors were the best predictors of each course type, while controlling for socio-demographic differences between the groups. Results: A total of 280 students responded. Compared to the non-PBL students (N = 197), the PBL students (N = 83) were significantly more likely to agree that: they did not know what the faculty expected of them (Odds Ratio (OR) = 0.38, p = 0.03); there were too many small group sessions facilitated only by students resulting in an unclear curriculum (OR = 0.04, p < 0.0001); and that there was a lack of opportunity to explore academic subjects of interest (OR = 0.40, p = 0.02). They were significantly more likely to disagree that: there was a lack of encouragement from teachers (OR = 3.11, p = 0.02); and that the medical course fostered a sense of anonymity and feelings of isolation amongst students (OR = 3.42, p = 0.008). Conclusion: There are significant differences in the perceived course-related stressors affecting medical students on PBL and non-PBL programmes. Course designers and student support services should therefore tailor their work to minimise, or help students cope with, the specific stressors on each course type to ensure optimum learning and wellbeing among our future doctors

Characterisation of tumour microenvironment remodelling following oncogene inhibition in preclinical studies with imaging mass cytometry

Mouse models are critical in pre-clinical studies of cancer therapy, allowing dissection of mechanisms through chemical and genetic manipulations that are not feasible in the clinical setting. In studies of the tumour microenvironment (TME), multiplexed imaging methods can provide a rich source of information. However, the application of such technologies in mouse tissues is still in its infancy. Here we present a workflow for studying the TME using imaging mass cytometry with a panel of 27 antibodies on frozen mouse tissues. We optimise and validate image segmentation strategies and automate the process in a Nextflow-based pipeline (imcyto) that is scalable and portable, allowing for parallelised segmentation of large multi-image datasets. With these methods we interrogate the remodelling of the TME induced by a KRAS G12C inhibitor in an immune competent mouse orthotopic lung cancer model, highlighting the infiltration and activation of antigen presenting cells and effector cells