Microstructured tungsten thermophotovoltaic selective emitters c by Natalija (Zorana) Jovanović.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 71-74).This research investigates the fabrication, modeling, characterization, and application of tungsten two-dimensional (2D) photonic crystal (PhC) structures as selective emitters and means of achieving higher efficiencies in thermophotovoltaic (TPV) energy conversion systems. Important aspects of the fabrication process are researched, developed, and rigorously characterized, focusing on dimensional reliability, precision, and repeatability of the processes. A major contribution in the form of tungsten reactive ion etch (RIE) characterization is provided with detailed parameters and second-order influences on etch rate, smoothness, and mask erosion. Optical characterization of our prototypes is found to be in excellent agreement with simulation, and has provided an experimental confirmation of selective emitter performance. We show that selective emitters can substantially increase spectral efficiency, providing as much as three times the radiative power density of planar tungsten. We include the first measurement of 96% combined efficiency of a selective emitter and a dielectric stack mirror for TPV system applications.Sc.D

Incidence and long-term outcome of severe asthma-COPD overlap compared to asthma and COPD alone:a 35-year prospective study of 57,053 middle-aged adults

BACKGROUND: Incidence and prognosis for severe asthma–COPD overlap is poorly characterized. We investigated incidence and long-term outcome for patients with asthma–COPD overlap compared to asthma and COPD alone. MATERIALS AND METHODS: A total of 57,053 adults (aged 50–64 years) enrolled in the Danish Diet, Cancer, and Health cohort (1993–1997) were followed in the National Patients Registry for admissions for asthma (DJ45–46) and COPD (DJ40–44) and vital status. Asthma–COPD overlap was defined as at least one hospital admission for asthma and one for COPD (different time points), and incident asthma–COPD overlap as at least one of the diagnoses occurring after enrollment into the Diet, Cancer, and Health cohort. RESULTS: A total of 1,845 (3.2%) and 4,037 (7.1%) participants had admissions for asthma and COPD, respectively, with 662 (1.2%) participants with asthma–COPD overlap. Incidence rate of asthma–COPD overlap per 1,000 person-years was higher in women (0.73) than in men (0.54) (P<0.02). Mortality rate was higher in asthma–COPD overlap (25.9 per 1,000 person-years) compared with COPD (23.1, P<0.05) and asthma (7.9, P<0.001) alone. Compared to COPD alone, mortality was higher in women with asthma–COPD overlap (19.6 and 25.5, respectively; P<0.01), and the excess mortality rate for asthma–COPD overlap patients was most prominent for younger age groups (12.9 compared to 7.2 and 4.6 for COPD and asthma alone, respectively; P<0.01). CONCLUSION: This large population-based study revealed a higher incidence of severe asthma–COPD overlap in women compared to men, and furthermore that all-cause mortality is higher in women and younger subjects with asthma–COPD overlap compared with those with asthma or COPD alone

Climate change and respiratory disease: clinical guidance for healthcare professionals.

UNLABELLED Climate change is one of the major public health emergencies with already unprecedented impacts on our planet, environment and health. Climate change has already resulted in substantial increases in temperatures globally and more frequent and extreme weather in terms of heatwaves, droughts, dust storms, wildfires, rainstorms and flooding, with prolonged and altered allergen and microbial exposure as well as the introduction of new allergens to certain areas. All these exposures may have a major burden on patients with respiratory conditions, which will pose increasing challenges for respiratory clinicians and other healthcare providers. In addition, complex interactions between these different factors, along with other major environmental risk factors (e.g. air pollution), will exacerbate adverse health effects on the lung. For example, an increase in heat and sunlight in urban areas will lead to increases in ozone exposure among urban populations; effects of very high exposure to smoke and pollution from wildfires will be exacerbated by the accompanying heat and drought; and extreme precipitation events and flooding will increase exposure to humidity and mould indoors. This review aims to bring respiratory healthcare providers up to date with the newest research on the impacts of climate change on respiratory health. Respiratory clinicians and other healthcare providers need to be continually educated about the challenges of this emerging and growing public health problem and be equipped to be the key players in solutions to mitigate the impacts of climate change on patients with respiratory conditions. EDUCATIONAL AIMS To define climate change and describe major related environmental factors that pose a threat to patients with respiratory conditions.To provide an overview of the epidemiological evidence on climate change and respiratory diseases.To explain how climate change interacts with air pollution and other related environmental hazards to pose additional challenges for patients.To outline recommendations to protect the health of patients with respiratory conditions from climate-related environmental hazards in clinical practice.To outline recommendations to clinicians and patients with respiratory conditions on how to contribute to mitigating climate change

Teksturalne i fizikalno-kemijske karakteristike bijelih kozjih sireva u salamuri od smrznutog mlijeka i gruša. Primjena kvadratnog I - odstupanja

Objective of this study was to investigate the effect of short term frozen storage of milk and curd on textural properties and physico-chemical composition of white brined goat cheese. Raw milk and curds (at various stages of pressing) were frozen and kept for seven days at -27 °C. Following the freezing, all the experimental cheeses were manufactured by the standard procedure, the same that was used for the control cheese sample which did not undergo freezing at any stage of production. The Square I - distance was used in order to rank the cheeses according to their similarity to the control cheese in terms of texture attributes and physico-chemical characteristics. The results show that, in terms of all examined variables, the cheese made from frozen milk is the most similar to the control cheese.Cilj ovog istraživanja bio je istpitivanje utjecaja kratkotrajnog skladištenja smrznutog mlijeka i gruša na teksturalne i fizikalno-kemijske karakteristike kozjeg bijelog sira u salamuri. Sirovo mlijeko i gruš (u različitim fazama prešanja) smrznuti su i skladišteni sedam dana na temperaturi od -27 °C. Po odmrzavanju, svi eksperimentalni sirevi proizvedeni su prema standardnoj proceduri, identičnoj kao i za kontrolni sir, koji nije bio podvrgnut smrzavanju ni u jednoj fazi proizvodnje. Kvadratno I – odstupanje primijenjeno je pri rangiranju eksperimentalnih sireva prema sličnosti s kontrolnim sirom u smislu teksture i fizikalno-kemijskih karakteristika. Rezultati pokazuju da je sir od smrznutog mlijeka najsličniji kontrolnom siru prema svim ispitivanim parametrima teksture i fizikalno-kemijskih karakteristika

Allergies to food and airborne allergens in children and adolescents:role of epigenetics in a changing environment

Allergic diseases affect millions of children and adolescents worldwide. In this Review, we focus on allergies to food and airborne allergens and provide examples of prevalence trends during a time when climate change is of increasing concern. Profound environmental changes have affected natural systems in terms of biodiversity loss, air pollution, and climate. We discuss the potential links between these changes and allergic diseases in children, and the clinical implications. Several exposures of relevance for allergic disease also correlate with epigenetic changes such as DNA methylation. We propose that epigenetics could be a promising tool by which exposures and hazards related to a changing environment can be captured. Epigenetics might also provide promising biomarkers and help to elucidate the mechanisms related to allergic disease initiation and progress.</p

Allergies to food and airborne allergens in children and adolescents: role of epigenetics in a changing environment.

Allergic diseases affect millions of children and adolescents worldwide. In this Review, we focus on allergies to food and airborne allergens and provide examples of prevalence trends during a time when climate change is of increasing concern. Profound environmental changes have affected natural systems in terms of biodiversity loss, air pollution, and climate. We discuss the potential links between these changes and allergic diseases in children, and the clinical implications. Several exposures of relevance for allergic disease also correlate with epigenetic changes such as DNA methylation. We propose that epigenetics could be a promising tool by which exposures and hazards related to a changing environment can be captured. Epigenetics might also provide promising biomarkers and help to elucidate the mechanisms related to allergic disease initiation and progress