Cold acclimation entails changes in membrane composition, osmotic adjustment, alterations in the cell wall-plasma membrane interface, sugar deposition, and changes in cell wall proteins. There is evidence that a rigid cell wall may be necessary for cold acclimation. Difficulties arise in studying plant material acclimated by exposure to low temperatures, because extraneous changes in the plant material occur that are unrelated to the development of cold tolerance. In order to determine whether cell wall changes are necessary for acclimation, peas were acclimated at warm temperature (26°C) by the application of exogenous ABA, desiccation, light exposure, and an experimental cryoprotectant (GLK 8908). Electrolyte leakage, elastic and plastic bend angles, and stem elongation were used to evaluate freezing injury, cell wall rigidity, and growth, respectively. The role of extensin, a structural hydroxyproline-rich glycoprotein suspected of being involved in cell changes during acclimation, was examined using the hydroxylation inhibitor ⍺,⍺’-dipyridyl. Exogenous ABA application and drought stress decreased freezing injury by approximately a 10% -6°C compared to controls. In one experiment light was found to be more effective than ABA at acclimating peas at warm temperatures. Foliar application of GLK 8908 decreased freezing injury (30% at -6°C). Stem bendability was not correlated with freezing resistance. ABA treated peas grown in the dark had reduced growth rates and increased stem rigidity, but exhibited greater injury at -6°C than untreated dark grown peas. Extensin content was not related to cold hardiness. Although acclimation of ’Alaska’ peas did occur at warm temperatures with various treatments the reductions in freezing injury were minor when compared to plants acclimated by exposure to low temperatures. GLK 8908 was also evaluated for its effects on ’Alaska’ pea survivability and yield. Peas treated with GLK 8908 (1 and 10% aqueous) and subjected to a -6.7°C freeze were found to have increased survival without significant changes in days to first flower, leaf surface area/plant, and yield/plant. / Master of Science

In the Canadian arctic, winter roads are engineered across the frozen land, rivers, and lakes. The strength and longevity of these roads depends on particular weather conditions. / Our research focuses on the winter road between Tulita and Norman Wells, Northwest Territories, open since 1982. The opening dates for the winter road are statistically analyzed. Five extreme early-opening years and five extreme late-opening years are determined and subsequently compared to both surface weather observations and large-scale synoptic structures prior to the opening dates for these years. Results show extreme late years are strong El Nino seasons, and extreme early years are colder and have more precipitation during November, than the 1971--2000 climatology. / The analysis of meteorological conditions near Norman Wells, associated with the extreme opening dates for this winter road, provides planners with more precise information germane to this road construction.

No description available.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-05-30T11:44:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_fernando_nunes_lopes.pdf: 2343988 bytes, checksum: 48c9096c9f757071d333975f35bae5d1 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-05-30T20:21:10Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_fernando_nunes_lopes.pdf: 2343988 bytes, checksum: 48c9096c9f757071d333975f35bae5d1 (MD5) / Made available in DSpace on 2017-05-30T20:21:10Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_fernando_nunes_lopes.pdf: 2343988 bytes, checksum: 48c9096c9f757071d333975f35bae5d1 (MD5) Previous issue date: 2015-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Variações diárias nas condições de tempo e clima, seja a nível local ou global, têm frequentemente afetado a saúde da população, cujos problemas variam desde um simples mal-estar, até transtornos de maior gravidade, podendo levar à morte. As doenças respiratórias podem ser agravadas ou até mesmo desencadeadas por fatores meteorológicos. O conhecimento dos ciclos sazonais, ou de escala menor (intra-sazonal) das variáveis do tempo nos permite antecipar algumas mudanças biológicas no ser humano, como, por exemplo, as que ocorrem devido ao vírus RSV e Influenza, responsável por desencadear infecções respiratórias. Este estudo tem como objetivo analisar as condições de tempo favoráveis ao aparecimento de doenças respiratórias em crianças menores de nove anos, na cidade de Pelotas-RS, no período 2008 a 2013 e, assim, introduzir uma metodologia para estimativa de períodos mais críticos a estas enfermidades. Foram utilizados dados de variáveis meteorológicas obtidos da estação convencional do Instituto Nacional de Meteorologia (INMET), bem como informações de internações hospitalares de crianças, junto ao Hospital Universitário São Francisco de Paula (HUFSP), da cidade de Pelotas. Os resultados mostraram que invernos anômalos, com ingressos de fortes massas de ar frio e úmido na região estabelecem períodos (dias) favoráveis ao desencadeamento/agravamento de infecções respiratórias e que três dias após a entrada de sistemas meteorológicos que provocam altos valores locais de umidade, baixa temperatura e grande mudança na direção do vento é maior a possibilidade de internação hospitalar, concordando com outros pesquisadores, sobretudo, quanto aos grupos mais suscetíveis a esse tipo de tempo, crianças e idosos. / Daily variations in weather and climate conditions have often affected the population health, since a simple malaise, to more severe disorders, which may lead to death. Respiratory diseases can be aggravated or even triggered by meteorological factors. The previous analysis of the seasonal or smaller scale behavior (intra-seasonal) of the weather parameters can help to anticipate some biological changes in human beings, for example, those that occur due to virus RSV and influenza responsible for respiratory infections. This study aims to analyze the weather conditions favorable to the respiratory diseases in children below nine years in the Pelotas city, in 2008-2013 and introduce a methodology for estimating the most critical periods these diseases. We used meteorological data from the conventional station of the Instituto Nacional de Meteorologia (INMET) and hospital admission data of children from the Hospital Universitário São Francisco de Paula (HUSFP), located in Pelotas city. The results showed that anomalous winters with strong cold and humid air masses in region set periods (days) favorable to the onset / worsening respiratory infections. It occurs three days after the entry of weather systems that cause high local values of moisture, low temperatures and a large change in the wind direction. This condition increases the possibility of hospitalization, according to other researchers, particularly on the most susceptible groups, such as children and the elderly.

<p>I denna uppsats har det studerats hur kyla påverkar Robot 70 skyttens prestanda. För att göra detta har en hypotesprövande metod använts. Hypotesen lyder: ”En robotskytts finmotorik påverkas av kyla så till den grad att träff inte är sannolik.”</p><p>Hypotesen används till hjälp att svara på följande frågeställningar:</p><p>Frågeställning 1:</p><p>I vilken utsträckning påverkas robot 70-skyttens finriktningsförmåga av kyla?</p><p>Frågeställning 2:</p><p>Hur kan luftvärnsregementet förbättra nyttjandet av Robot 70 gruppens utrustning för att minska kylans påverkan på robotskyttens prestanda?</p><p>Ett experiment har använts för att verifiera eller falsifiera hypotesen. Sju personer från Luftvärnsregementet har skjutit simulerade avfyringar inom- och utomhus, vid olika temperaturer. Resultatet från robotarna avfyrade inomhus vid 20°C hade en ungefärlig träffsannolikhet för direktträff på 94 %. Avfyringarna i segmentet med lägst uppmätta tumtemperaturer hade enligt mina mätningar en betydligt lägre träffsannolikhet för direktträff.</p><p>Vad som verkar sänka temperaturen robotskyttens tumme mest, är värmeledning från robotsystemets styrspak. Slutsatsen är att detta verkar beror på att styrspaken är tillverkad av aluminium. Genom att isolera styrspaken kan det undvikas att skyttens tumme kyls ned och därmed minskar dennes träffsannolikhet.</p> / <p>In this essay it has been studied how cold environment can affect the gunner of the RBS 70.</p><p>In this study, the method of testing a hypothesis has been used. Hypothesis: “The Gunner is affected by cold to such an extent that a hit is not probable”</p><p>The hypothesis is used in helping to answer the following two questions:</p><p><strong>1.      </strong>To what level is the RBS 70 Gunner affected by cold?</p><p><strong>2.      </strong>How can the Swedish AD Regiment improve its use of equipment in order to   reduce the effects of cold weather, on the RBS 70 gunners’ ability to aim?</p><p> A test was performed to verify or falsify the hypothesis. Seven people from the Swedish AD Regiment fired simulated missiles both indoors and outdoors, in different temperatures. The results show that the missiles fired indoors at 20°C had an approximated direct hit-ratio of 94 percent. The firings where the thumb temperatures were the lowest had a lot lower direct hit ratio.</p><p>The greatest issue lowering the gunners thumb temperature was the temperature of the joystick of the sight. The conclusions are that the joystick, which is made of aluminium, must be isolated to avoid cooling the gunners’ thumb. Otherwise it will be harder to hit the target at a low temperature.</p>

I denna uppsats har det studerats hur kyla påverkar Robot 70 skyttens prestanda. För att göra detta har en hypotesprövande metod använts. Hypotesen lyder: ”En robotskytts finmotorik påverkas av kyla så till den grad att träff inte är sannolik.” Hypotesen används till hjälp att svara på följande frågeställningar: Frågeställning 1: I vilken utsträckning påverkas robot 70-skyttens finriktningsförmåga av kyla? Frågeställning 2: Hur kan luftvärnsregementet förbättra nyttjandet av Robot 70 gruppens utrustning för att minska kylans påverkan på robotskyttens prestanda? Ett experiment har använts för att verifiera eller falsifiera hypotesen. Sju personer från Luftvärnsregementet har skjutit simulerade avfyringar inom- och utomhus, vid olika temperaturer. Resultatet från robotarna avfyrade inomhus vid 20°C hade en ungefärlig träffsannolikhet för direktträff på 94 %. Avfyringarna i segmentet med lägst uppmätta tumtemperaturer hade enligt mina mätningar en betydligt lägre träffsannolikhet för direktträff. Vad som verkar sänka temperaturen robotskyttens tumme mest, är värmeledning från robotsystemets styrspak. Slutsatsen är att detta verkar beror på att styrspaken är tillverkad av aluminium. Genom att isolera styrspaken kan det undvikas att skyttens tumme kyls ned och därmed minskar dennes träffsannolikhet. / In this essay it has been studied how cold environment can affect the gunner of the RBS 70. In this study, the method of testing a hypothesis has been used. Hypothesis: “The Gunner is affected by cold to such an extent that a hit is not probable” The hypothesis is used in helping to answer the following two questions: 1.      To what level is the RBS 70 Gunner affected by cold? 2.      How can the Swedish AD Regiment improve its use of equipment in order to   reduce the effects of cold weather, on the RBS 70 gunners’ ability to aim?  A test was performed to verify or falsify the hypothesis. Seven people from the Swedish AD Regiment fired simulated missiles both indoors and outdoors, in different temperatures. The results show that the missiles fired indoors at 20°C had an approximated direct hit-ratio of 94 percent. The firings where the thumb temperatures were the lowest had a lot lower direct hit ratio. The greatest issue lowering the gunners thumb temperature was the temperature of the joystick of the sight. The conclusions are that the joystick, which is made of aluminium, must be isolated to avoid cooling the gunners’ thumb. Otherwise it will be harder to hit the target at a low temperature.

Ice accretion is a purely unsteady phenomenon that is presently approximated by most icing codes using quasi-steady modeling. The accuracy of ice prediction is thus directly related to the arbitrarily prescribed time span during which the impact of ice growth on both flow and droplets is neglected. The objective of this work is to remove this limitation by implementing a cost-effective unsteady approach. This is done by fully coupling, in time, a diphasic flow (interacting air and droplet particles) with the ice accretion model. The two-phase flow is solved using the Navier-Stokes and Eulerian droplet equations with dual-time stepping in order to improve computational time. The ice shape is either obtained from the conservation of mass and energy within a thin film layer for glaze and mixed icing conditions, or from a mass balance between water droplets impingement and mass flux of ice for rime icing conditions. The iced surface being constantly displaced in time, Arbitrary Lagrangian-Eulerian terms are added to the governing equations to account for mesh movement. Moreover, surface smoothing techniques are developed to prevent degradation of the iced-surface geometric discretization. For rime ice, the numerical results clearly show that the new full unsteady modeling improves the accuracy of ice prediction, compared to the quasi-steady approach, while in addition ensuring time span independence. The applicability of the unsteady icing model for predicting glaze ice accretion is also demonstrated by coupling the diphasic model to the Shallow Water Icing Model. A more rigorous analysis reveals that this model requires the implementation of local surface roughness and that previous quasi-steady validations cannot be carried out using a small number of shots, therefore the need for unsteady simulation.

Even though the power of supercomputers has increased extraordinarily, there is still an insatiable need for more advanced multi-disciplinary CFD simulations in the aircraft analysis and design fields. A particular current interest is in the realistic three-dimensional fully viscous turbulent flow simulation of the highly non-linear aspects of aero-icing. This highly complex simulation is still computationally too demanding in industry, especially when several runs, such as parametric studies, are needed. In order to make such compute-intensive simulations more affordable, this work presents a reduced order modeling approach, based on the "Proper Orthogonal Decomposition", (POD), method to predict a wider swath of flow fields and ice shapes based on a limited number of "snapshots" obtained from complete high-fidelity CFD computations. The procedure of the POD approach is to first decompose the fields into modes, using a limited number of full-calculations snapshots, and then to reconstruct the field and/or ice shapes using those decomposed modes for other conditions, leading to reduced order calculations. The use of the POD technique drastically reduces the computational cost and can provide a more complete map of the performance degradation of an iced aircraft over a wide range of flight and weather conditions.

This study examined the differences in decomposition rates and the resulting postmortem submergence interval (PMSI) of stillborn pigs and decapitated adult pig heads enclosed in plastic trash bags. Sixteen neonate pigs were divided into two variable categories: exposed and submerged in water, enclosed in a plastic trash bag and submerged in water. Upon recovery, each sample was assigned a Total Body Score. Eighteen decapitated adult pig heads were divided into two variable categories: nine heads were enclosed in plastic trash bags, and nine heads left exposed in the water. Twelve decapitated pig heads were divided into two terrestrial variable categories: six heads were enclosed in plastic trash bags and allowed to decompose on land, and six heads were left exposed on land. Accumulated degree-days (ADD) were calculated following the scoring guides provided in Moffatt et al. (2016), Megyesi et al. (2005) and Heaton et al. (2010). These guides were used to create a baseline decomposition rate established from the control groups decay rate. This baseline in the decomposition rate was then used to establish a measurable difference between exposed and enclosed samples. It was hypothesized that head samples submerged (enclosed/exposed) would decompose slower than the terrestrial samples (enclosed/exposed). It was further hypothesized that all enclosed/submerged samples would decompose slower than the exposed/terrestrial remains. A univariate analysis of variance (ANOVA) test found no statistically significant interactions between submerged, enclosed or exposed remains, indicating that the enclosure of remains in a plastic trash bag, and subsequent submergence or not did not affect the decomposition rate of either sample. An additional ANOVA found statistically significant differences between the rate of neonate sample decomposition and adult head sample decomposition. Paired sample t-tests produced statistically significant results that indicate the inaccuracy of the ADD calculation methods developed by Megyesi et al. (2005) and Heaton et al. (2010) to neonate-sized remains, decapitated heads, submerged enclosed/exposed samples or terrestrial enclosed/exposed samples.

The homeless population in Anchorage, Alaska faces many unique challenges. Over the past several winters, a number of homeless individuals have succumbed to the effects of exposure despite available cold weather services. This study investigated individual experiences within the homeless population of Anchorage, Alaska during times of inclement winter weather. Self-determination theory was used to explore motivations of behaviors of the population and to uncover the reasons why this population does not use cold weather services offered by the Municipality of Anchorage. The research questions addressed participant awareness of available cold weather services, survival strategies during inclement winter weather, and barriers to cold weather service use. This phenomenological study examined those lived experiences. Purposeful sampling was used to recruit eligible individuals (n = 14) at a local soup kitchen, and participants engaged in semistructured interviews. Data analysis procedures used McCormack's lenses and horizontalization to reveal emerging themes. Key findings included a lack of knowledge of emergency services, various survival strategies, and self-imposed barriers to services. The implications of these emerging revelations may positively influence public health providers to modify education delivery methods and interventions used to reach the homeless population in Anchorage, Alaska, with the ultimate goal of preventing wintertime mortalities.