Analysis on frosting of heat exchanger and numerical simulation of heat transfer characteristics using BP neural network learning algorithm.

The study is aimed at the frosting problem of the air source heat pump in the low temperature and high humidity environment, which reduces the service life of the system. First, the frosting characteristics at the evaporator side of the air source heat pump system are analyzed. Then, a new defrost technology is proposed, and dimensional theory and neural network are combined to predict the transfer performance of the new system. Finally, an adaptive network control algorithm is proposed to predict the frosting amount. This algorithm optimizes the traditional neural network algorithm control process, and it is more flexible, objective, and reliable in the selection of the hidden layer, the acquisition of the optimal function, and the selection of the corresponding learning rate. Through model performance, regression analysis, and heat transfer characteristics simulation, the effectiveness of this method is further confirmed. It is found that, the new air source heat pump defrost system can provide auxiliary heat, effectively regulating the temperature and humidity. The mean square error is 0.019827, and the heat pump can operate efficiently under frosting conditions. The defrost system is easy to operate, and facilitates manufactures designing for different regions under different conditions. This research provides reference for energy conservation, emission reduction, and sustainable economic development.

Moisture associated skin damage (MASD) in intensive care patients: A Norwegian point-prevalence study.

BACKGROUND: Critically ill patients are at risk of developing moisture associated skin damage and pressure ulcers. These conditions may co-exist and be difficult to distinguish, but a simultaneous investigation may provide a true prevalence. OBJECTIVES: To investigate the prevalence of moisture associated skin damage and associated factors among Norwegian intensive care patients. METHODS: A multi-centre one-day point-prevalence study. RESULTS: Totally, 112 patients participated in the study. Overall, 15 patients (13%, 15/112) had some type of moisture associated skin damage of which six cases (5%, 6/112) were related to faeces and/or urine (incontinence associated dermatitis). Skin breakdown occurred primarily in the pelvic area. Overall, 87% (97/112) had an indwelling urinary catheter. Stools were reported in 42% (47/112) of the patients on the study day, mostly liquid or semi-liquid. Overall, 11% (12/112) had a faecal management system. Only a few care plans for moisture associated skin damage prevention and care existed. CONCLUSION: Patients in this study were vulnerable to skin breakdown in the pelvic area. Nevertheless, a low prevalence of skin breakdown existed. This may relate to intensive care nurses' qualifications, the 1:1 nurse-patient staffing, the high prevalence of urinary catheters and few patients having stools.

A Low-Cost Humidity Control System to Protect Microscopes in a Tropical Climate.

Introduction: A clean and functional microscope is necessary for accurate diagnosis of infectious diseases. In tropical climates, high humidity levels and improper storage conditions allow for the accumulation of debris and fungus on the optical components of diagnostic equipment, such as microscopes. Objective: Our objective was to develop and implement a low-cost, sustainable, easy to manage, low-maintenance, passive humidity control chamber to both reduce debris accumulation and microbial growth onto the optical components of microscopes. Methods: Constructed from easily-sourced and locally available materials, the cost of each humidity control chamber is approximately $2.35 USD. Relative humidity levels were recorded every 30 minutes over a period of 10 weeks from two chambers deployed at the Belize Vector and Ecology Center and the University of Belize. Results: The humidity control chamber deployed at the University of Belize maintained internal relative humidity at an average of 35.3% (SD = 4.2%) over 10 weeks, while the average external relative humidity was 86.4% (SD = 12.4%). The humidity control chamber deployed at the Belize Vector and Ecology Center effectively maintained internal relative humidity to an average of 54.5% (SD = 9.4%) over 10 weeks, while the average external relative humidity was 86.9% (SD = 12.9%). Conclusions: Control of relative humidity is paramount for the sustainability of medical equipment in tropical climates. The humidity control chambers reduced relative humidity to levels that were not conducive for fungal growth while reducing microscope contamination from external sources. This will likely extend the service life of the microscopes while taking advantage of low-cost, locally sourced components.

Challenges of dispensing costly tablets with short shelf-life.

Afatinib, trametinib and regorafenib are three costly oral oncology drugs with a short shelf-life after the original container has been opened. Their short shelf-lives are due to degradation on exposure to moisture. Therefore, manufacturers recommend them to be dispensed in the original packaging with the desiccant. However, the prescribed quantities do not always match the quantities in the original packaging, usually because of dose modifications for toxicities. This leads to potentially significant drug wastage and financial losses. We describe some potential approaches to this issue.

The relationship between nurses assessment of early pressure ulcer damage and sub epidermal moisture measurement: A prospective explorative study.

AIM: To explore the relationship between nurses' visual assessment of early pressure ulceration and assessment using sub epidermal moisture measurement (a measure of skin and tissue water). MATERIALS AND METHODS: A descriptive prospective observational study design was employed. Following ethical approval and written informed consent, data were collected daily, for four weeks, from at risk patients within an acute care facility in Ireland. Data included nurses documented assessment of the patient's skin condition and researcher led sub epidermal moisture measurement, over the sacrum and both heels. RESULTS: A total of 47 patients were included, 38.3% (n = 18) were male and 61.5% (n = 29) were female, with a mean age of 74.7 years. Nineteen patients (40%) developed 21 Stage 1 pressure ulcers and all of these had sustained elevated sub epidermal moisture (SEM) levels before visual signs of damage became evident indicating 100% sensitivity of SEM readings in predicting pressure ulceration. Specificity was 83% with the majority of false positives having insufficient follow-up time. Furthermore a medium correlation between nurses' visual skin assessment (the current gold standard in pressure ulcer detection) and SEM findings (r = .47; p = 0.001) was identified. The mean number of days for nurses to detect this damage was 5.5 (±2,5; max 11, min 2), whereas the mean number of days that it took SEM measurement to detect damage was 1.5 (±1.4; max 7, min 1). SEM measurement identified early damage, on average, 4 days sooner than nurses' assessment. CONCLUSION: Given that pressure ulcers develop from within the deeper tissues, knowing that early pressure ulcer damage is present can facilitate heightening of prevention strategies to avoid extension. This is of importance in clinical practice as the earlier that pressure ulcers can be detected; the earlier interventions can be implemented to prevent further extension, avoiding their associated morbidity and mortality.

Associations between air pollution, climate factors and outpatient visits for eczema in West China Hospital, Chengdu, south-western China: a time series analysis.

BACKGROUND: Eczema is one of the most common inflammatory dermatoses that can be provoked as a result of external and internal factors. With dense population and rapid economic development of China, air pollution is still a serious problem and the prevalence of eczema has been elevating. OBJECTIVE: To determine the association and lagged effects between environmental factors and the outpatient visits for eczema. METHODS: Data of daily outpatient visits for eczema at the clinics of dermatology in West China Hospital within the last 5 years were collected. Data of environmental factors of Chengdu during the same period, including temperature, relative humidity, barometric pressure, wind speed and air pollutants concentrations like sulphur dioxide (SO2 ), nitrogen dioxide (NO2 ) and particular matter (PM10 ), were gathered. The distributed lag nonlinear model was used to statistically examine the relationship between eczema and environmental factors and their lagged effects. RESULTS: Correlation analysis showed that eczema outpatient visits were positively correlated with the air pollutants and were negatively correlated with relative humidity. The barometric pressure and wind speed influenced the outpatient visits in association with air pollutants. CONCLUSION: This study provides evidence that environmental factors like relative humidity and multiple air pollutants influence the incidence and prevalence of eczema and have lagged effects.

Assessment of surface caking of powders using the ball indentation method.

Powder caking is a ubiquitous problem, which could significantly decrease product quality and lead to economic losses. Hence it is important to know the conditions under which it occurs. The caking behaviour of three powder materials (PVP, HPC and CaHPO4) has been investigated by the ball indentation method (BIM) as affected by relative humidity (RH), temperature and time. The resistance to powder flow, as indicated by the hardness is measured by a ball indenting the powder bed surface. The surface hardness increases with increasing RH and temperature, indicating caking of the powder bed. Moreover, the temperature and RH show a coupled effect on powder caking. Irreversible caking is formed in PVP and HPC at 75% RH; the particles coalesce and the volume of powder bed is significantly reduced with time. However, the caking of CaHPO4 is reversible. To examine the caking mechanism of PVP and HPC, the critical glass transition RH is determined at 25°C and 45°C. The values are 63% and 53% RH for PVP and 61% and 50% RH for HPC, respectively. The glass transition moisture content in the ball indentation experiments is comparable with that determined by the dynamic vapor sorption measurement. BIM could be a fast and effective method for the assessment of powder surface caking.

Valuing the Economic Costs of Allergic Rhinitis, Acute Bronchitis, and Asthma from Exposure to Indoor Dampness and Mold in the US.

Two foundational methods for estimating the total economic burden of disease are cost of illness (COI) and willingness to pay (WTP). WTP measures the full cost to society, but WTP estimates are difficult to compute and rarely available. COI methods are more often used but less likely to reflect full costs. This paper attempts to estimate the full economic cost (2014$) of illnesses resulting from exposure to dampness and mold using COI methods and WTP where the data is available. A limited sensitivity analysis of alternative methods and assumptions demonstrates a wide potential range of estimates. In the final estimates, the total annual cost to society attributable to dampness and mold is estimated to be $3.7 (2.3-4.7) billion for allergic rhinitis, $1.9 (1.1-2.3) billion for acute bronchitis, $15.1 (9.4-20.6) billion for asthma morbidity, and $1.7 (0.4-4.5) billion for asthma mortality. The corresponding costs from all causes, not limited to dampness and mold, using the same approach would be $24.8 billion for allergic rhinitis, $13.5 billion for acute bronchitis, $94.5 billion for asthma morbidity, and $10.8 billion for asthma mortality.

Assessing the impact of humidex on HFMD in Guangdong Province and its variability across social-economic status and age groups.

Humidex is a meteorological index that combines the impacts of temperature and humidity, and is directly comparable with dry temperature in degrees Celsius. However, to date, no research has focused on the effect of humidex on hand, foot and mouth disease (HFMD). The current study was designed to address this research need. Case-based HFMD surveillance data and daily meteorological data collected between 2010 and 2012 was obtained from the China CDC and the National Meteorological Information Center, respectively. Distributed lag nonlinear models were applied to assess the impact of humidex on HFMD among children under 15 years oldin Guangdong, and its variability across social-economic status and age groups. We found that relative risk (RR) largely increased with humidex. Lag-specific and cumulative humidex-RR curves for children from the Pearl-River Delta Region as well as older children were more likely to show two-peak distribution patterns. One RR peak occurred at a humidex of between 15 and 20, and the other occurred between 30 and 35. This study provides a comprehensive picture of the impact of humidex on HFMD incidence in Guangdong Province. Results from the present study should be important in the development of area-and-age-targeted control programs.

Asthma related to workplace dampness and impaired work ability.

PURPOSE: To examine the long-term effects on work ability among patients previously diagnosed with occupational asthma (OA) or work-exacerbated asthma (WEA) or symptoms in relation to workplace dampness. METHODS: A questionnaire follow-up was used to study 1,098 patients (of whom 87 % were female) examined because of a suspected occupational respiratory disease caused by building dampness and mold. Self-rated work ability and early withdrawal from work were the two outcomes of the study. As determinants, we investigated the influence of the asthma diagnosis given in the initial examinations (OA or WEA), the number of persistent indoor air symptoms, and the psychosocial factors at work. RESULTS: With a mean follow-up of 7.8 years, 40 % of the OA patients, under 65 years of age, were outside worklife versus 23 % of the WEA patients and 15 % of the patients with only upper respiratory symptoms at baseline. The diagnosis of OA was associated with a nearly sixfold risk for early withdrawal from work in a comparison with a reference group with upper respiratory symptoms. A perceived poor social climate at work and poor experiences with supervisory co-operation were associated with impaired work ability outcomes. Those with multiple, long-term indoor air symptoms considerably more often perceived their work ability to be poor when compared with those with less significant symptoms. CONCLUSIONS: Adverse work ability outcomes are associated with asthma in relation to workplace dampness. The study raises the need for effective preventive measures in order to help workers with indoor air symptoms sustain their work ability.

Electronic momentary assessment of weather changes as a trigger of headaches in children.

BACKGROUND: Variables that are thought to precipitate migraine or tension-type headache episodes in children hitherto have only been studied using retrospective reports. As such, there is little empirical evidence to support the actual predictive association between presumed headache triggers and actual headache occurrence in children. OBJECTIVE: The present study sought to determine if fluctuations in weather, a commonly reported headache trigger in children, predict increased likelihood of headache occurrence when evaluated using rigorous prospective methodology ("electronic momentary assessment"). METHODS: Twenty-five children (21 girls, 4 boys) between the ages of 8-17 years attending a new patient neurology clinic appointment and having a diagnosis of chronic migraine, chronic tension-type, or episodic migraine headache (with or without aura) participated in the study. Children completed baseline measures on headache characteristics, presumed headache triggers, and mood and subsequently were trained in the use of electronic diaries to record information on headaches. Children then completed thrice daily diaries on handheld computers for a 2-week time period (42 assessments per child) while data on weather variables (temperature, dew point temperature, barometric pressure, humidity, precipitation, and sunlight) in the child's geographic location were recorded each time a diary was completed. Data were analyzed using multilevel models. RESULTS: Of the weather variables, relative humidity and presence of precipitation were significantly predictive of new headache onset, with nearly a 3-fold increase in probability of headache occurrence during times of precipitation or elevated humidity in the child's area, b = 0.38, t(821) = 2.10, P = .04, and b = 0.02, t(821) = 2.81, P = .01, respectively. These associations remained after accounting for fluctuations in mood, and associations were not significantly stronger in children who at baseline thought that weather was a headache trigger for them. Changes in temperature, dew point temperature, barometric pressure, and sunlight were not significantly predictive of new headache episode occurrence in this sample. CONCLUSIONS: Results of the present study lend some support to the belief commonly held by children with recurrent headaches that weather changes may contribute to headache onset. Although electronic momentary assessment methodology was found to be feasible in this population and to have the potential to identify specific headache triggers for children, it remains to be determined how best (or even whether) to incorporate this information into treatment recommendations.

Respiratory morbidity and medical visits associated with dampness and air-conditioning in offices and homes.

UNLABELLED: We used data from 4345 adult US residents who were part of a 2004 national random mail survey to investigate associations between dampness and air-conditioning (AC) in homes and offices, and health outcomes, sick leave due to respiratory symptoms and medical visits during the past 12 months. We identified from this group 1396 office workers employed in professional, executive, administrative, managerial or administrative support occupations. Office workers reporting home dampness had an elevated prevalence of nasal symptoms [prevalence ratio (PR) = 1.4, P = 0.01] and constitutional symptoms (PR = 1.3, P = 0.01) in the previous year. Office workers reporting workplace dampness had an elevated prevalence of sick leave attributed to respiratory symptoms (PR = 1.3, P = 0.04) in the previous year. Office workers with home AC were more likely to have visited a medical specialist in the previous year (PR = 1.3, P = 0.02). We did not find any statistically significant associations between workplace AC and any of the health outcomes. We estimated an annual cost of US$1.4 billion for excess respiratory-related sick leave among office workers with workplace dampness. Our study strengthens the evidence of a relationship between dampness and health effects, and highlights the resulting economic impact. PRACTICAL IMPLICATIONS: This study adds to the literature on respiratory morbidity associated with home and office exposures to mold and dampness. Public health response to lessen these exposures will improve the health and well-being of residents and workers as well as diminish the economic burden of lost work time and medical costs.

Safe and healthy school environments.

Children spend much of their waking time at school. Many of the factors in the school environment can be improved with careful planning and allocation of resources. The pediatrician, as a child advocate, is in an excellent position to influence the allocation of school resources to improve the educational outcome. This article summarizes some of the current understanding gathered from applying an environmental health approach to the school setting and provides a basis for the interested physician and other child advocate to learn more and get involved.

"The walls were so damp and cold" fuel poverty and ill health in Northern Ireland: results from a housing intervention.

This article reports the findings from an evaluation of a fuel poverty programme in the Armagh and Dungannon Health Action Zone in Northern Ireland. Focusing on a rural community, it adds to the debate surrounding the hidden nature of rural fuel poverty. As part of the programme, energy efficiency measures, including some central heating systems, were installed in 54 homes. Surveys were conducted both pre and post intervention and analysed to assess any changes. The programme demonstrated that energy efficiency intervention can lead to improvements in health and well being, increased comfort levels in the home and a reduction in the use of health services, therefore having potential cost savings for the NHS. Some households, however, remain in fuel poverty after having full central heating installed, reflecting the significant contribution of low income on the production of fuel poverty. The article concludes by suggesting that interventions in this area require commitment from multiple sectors of society, including health professionals and local communities.

From local concern to randomized trial: the Watcombe Housing Project.

BACKGROUND: A randomized study of the effect on people's health of improving their housing is underway in Torbay. The link between poor health, particularly respiratory health, and poor housing conditions has been recognized for a long time, but there have been few intervention studies to demonstrate that improving housing can improve health. In 1994, South and West Devon Health Authority set up a community development project in a deprived area of Torbay, in response to the concerns of local primary health-care workers. A community development worker helped local residents survey their homes for dampness and record their respiratory symptoms. The survey reported high levels of condensation/dampness and respiratory illness and the Council agreed to direct the majority of their housing improvement funds to the estate over the next 3 years. The Health Authority, University of Plymouth and Torbay Council were successful in obtaining funding to evaluate the housing improvements from the NHS R & D programme. PARTICIPANTS AND METHODS: Of 119 houses eligible for the study, 50 were chosen at random and improved in the first year. The rest were improved the following year. Questionnaires screening for health problems were sent to all 580 residents and baseline surveys of the indoor environment were also carried out. More detailed health surveys were completed by community nurses visiting residents in their homes. All adults were asked to complete SF-36 and GHQ 12 questionnaires, as well as disease-specific questionnaires if appropriate. PROGRESS: All houses in the study have now been improved, including insulation, double-glazing, re-roofing, heating, ventilation and electrical rewiring. Follow-up surveys are underway.

Clothing, assessment and effects on thermophysiological responses of man working in humid heat.

This paper presents the relative importance of the different factors to be taken into account when predicting thermal exchanges when man is wearing garments while being exposed to warm environments. Factors considered are the thermal insulation of clothing (CLO), the thermal efficiency of clothing (Fcl), the clothing area factor (fcl), the pumping coefficient (p), the vapour permeation efficiency factor (Fpcl). As Fpcl depends on CLO, Fcl,fcl and p factors, physiological assessments of this factor appears to be necessary for the calculation of the maximum evaporative capacity (Emax) in clothed subjects. In this paper, comparisons of body temperatures, whole body and local sweating were made from data obtained on both unclothed and then clothed subjects working at 50 watts on a cycloergometer in warm environments (Ta = Tr = Tsk), with increasing ambient humidity levels (Pa). Results showed that clothed subjects sweated more than unclothed man for the same Pa increases and hidromeiosis occurring on the skin of unclothed man seemed to be responsible for this. Sweat accumulation in the clothes confirms that the decrease in the evaporative sweat efficiency for clothed subjects was closely associated with the threshold for occurrence of core temperature drift. However the less important slope in the Tcore vs delta Pa relationship for clothed subjects compared to that for unclothed implies a more efficient body cooling thanks to clothing, which does not lead to as great a physiological disadvantage as expected. Pumping effect and additional concurrent evaporation could account for this phenomenon: the ISO model (Required sweat rate) which includes an additional air velocity as a function of metabolism allows us to consider this beneficial influence of increased Emax in clothed subjects. However this effect should not be considered when the model is used for unclothed subjects.