Mosquitoes are the deadliest animal on the planet killing about a million people a year. These insects are competent vectors of multiple pathogens (e.g., Plasmodium sp, filarial worms, and arboviruses). In most species, females are blood feeders, and must consume a blood meal to complete a gonotrophic cycle. Extensive research has been conducted on hematophagy and host-seeking behaviors, but relatively little is known about phytophagy. Sugar feeding is an essential aspect of mosquito biology. Both male and female mosquitoes must consume sugar as a primary fuel source. Mosquitoes use olfactory and visual cues among other cues to find suitable food sources. Abiotic factors, such as temperature and humidity, have been shown to impact mosquito behaviors, including sugar feeding. Recently, sugar feeding has been identified as a promising control target for multiple species of mosquitoes. Attractive toxic sugar baits (ATSBs) attract both male and females through the use of plant derived volatiles. In this work, we first examined the effects of temperature and humidity on the survival of sugar fed Aedes aegypti. We showed that sugar feeding greatly increases longevity in optimal conditions and that humidity impacted survival while temperature less so. Second, we aimed at developing an ATSB for controlling Aedes j. japonicus mosquitoes. Overall, this work sheds light on the importance of abiotic factors and sugar feeding on mosquito survival and lays the groundwork for controlling an invasive mosquito species. / Master of Science in Life Sciences / Mosquitoes are the deadliest organisms on the planet killing about a million people each year due to the multitude of pathogens they may transmit (e.g., malaria parasites, Zika virus, dengue virus). Female mosquitoes transmit pathogens by taking blood meals to obtain essential nutrients needed to develop eggs. If knowledge on host-seeking behavior and blood-feeding is extensive, comparatively less is known about sugar feeding. Sugar feeding is an important behavior displayed by both male and female mosquitoes to obtain energy for flying, reproduction, and survival. Mosquitoes feed on a variety of sugar sources including plant nectar and decaying fruits. They use multiple different cues in order to locate suitable meals including olfaction and vision. Environmental factors such as temperature and humidity affect mosquito activity, dehydration, and sugar feeding. In the present work, we first examined the effects of temperature and humidity on survival in the major disease vector species, Aedes aegypti. As the global temperatures are increasing, it is essential to better understand how mosquitoes adapt and deal with environmental stressors in a changing world. We then aimed at exploiting sugar feeding behavior by developing a novel method of control for another invasive mosquito species, Aedes j. japonicus. Together, these results help us have a better understanding of mosquito biology and ecology which is crucial for predicting future distribution of invasive species and designing new control strategies.

Yes / Objectives  In this work we investigated the residual organic solvent content and physicochemical properties of spray-dried chlorothiazide sodium (CTZNa) and potassium (CTZK) salts. Methods  The powders were characterised by thermal, X-ray diffraction, infrared and dynamic vapour sorption (DVS) analyses. Solvent levels were investigated by Karl–Fischer titration and gas chromatography. Key findings  Spray-drying from water, methanol (MeOH) and mixes of MeOH and butyl acetate (BA) resulted in amorphous microparticles. The glass transition temperatures of CTZNa and CTZK were ∼192 and ∼159°C, respectively. These materials retained their amorphous nature when stored at 25°C in dry conditions for at least 6 months with no chemical decomposition observed. DVS determined the critical relative humidity of recrystallisation of CTZNa and CTZK to be 57% RH and 58% RH, respectively. The inlet temperature dependant oxidation of MeOH to formaldehyde was observed; the formaldehyde was seen to deposit within the amorphous matrix of spray-dried product. Spray-drying in the open blowing mode coupled with secondary drying resulted in a three-fold reduction in residual BA (below pharmacopoeial permitted daily exposure limit) compared to spray-drying in the closed mode. Conclusions  Experiments showed that recirculation of recovered drying gas increases the risk of deposition of residual solvents in the spray-dried product. / The Irish Research Council for Science and Engineering Technology (IRCSET), the Solid State Pharmaceutical Cluster (SSPC), supported by Science Foundation Ireland under grant number (07/SRC/B1158) and the Irish Drug Delivery Research Network, a Strategic Research Cluster grant (07/SRC/B1154) under the National Development Plan co-funded by EU Structural Funds and Science Foundation Ireland.

Water quality and space constraints have become major concerns regarding the No. 7 waste water dam at Petra Diamonds’ Cullinan mine. The unique location of the dam constrains further development, while unsustainable accumulation of waste water inside the dam increases the risk of potential environmental contamination from seepages and spillages. The dam retains a significant amount of very poor quality water. Its excessively high pH, dissolved salt content, density and extreme turbidity result from the concentration of natural weathering products of the diamond bearing kimberlite ore. The turbidity results from the dispersion of colloidal chlorite, saponite and nontronite clay. Along with the chemistry of the solution, their colloidal shape contributes equally significantly to the non-settlement of these suspended clays. Flocculation of the dispersed clay particles will provide (a) for easy and effective separation of the clay material from the waste water and (b) more convenient options for water treatment (and subsequent redistribution) This study was aimed at contributing to a better understanding of the dynamic interactions in the No 7 Dam system to contribute towards identifying a suitable means/method for chemical flocculation of the clay particles. The individual components of the system (clays, water quality) and influx contributors (kimberlite and its leachate) were systematically characterized by means of X-Ray Diffraction, X-Ray Fluorescence, petrographic microscopy, electron microscopy, electrophoretic mobility and standard water- and soil quality analyses. The baseline quality of the Cullinan kimberlite leachate was obtained based on ASTM D5744 principles. It was found that adjusting the pH-level and ionic strength of the waste water to the critical coagulation point (cK) (as determined by electrophoretic mobility and batch jar experiments) automatically induced coagulation. Higher valence cations were displaced from pH dependent surface charge sites by proton adsorption. The resultant increased ionic strength, in combination with decreased thickness of the ionic double layer, was sufficient for the automatic initiation of high strength disordered face-face and edge-face bonds. During batch Jar tests, flocculation initiated within 4 minutes after the addition of HCl (0.5 M) and total sedimentation completed within 3 hours. The use of commercial flocculants might decrease the sedimentation time. As expected a significant increase in dissolved salt content of the clear supernatant was observed. No re-dispersion of the dried clay occurred. Throughout the study geochemical modeling was performed with PHREEQC software to identify/determine possible effective experimental conditions, minimizing experimental time and expenses. The program was also used to model outcomes of the possible water treatment options, indicated in literature as viable options for similar situations. These options can be tested to extend upon the current research. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Water quality and space constraints have become major concerns regarding the No. 7 waste water dam at Petra Diamonds’ Cullinan mine. The unique location of the dam constrains further development, while unsustainable accumulation of waste water inside the dam increases the risk of potential environmental contamination from seepages and spillages. The dam retains a significant amount of very poor quality water. Its excessively high pH, dissolved salt content, density and extreme turbidity result from the concentration of natural weathering products of the diamond bearing kimberlite ore. The turbidity results from the dispersion of colloidal chlorite, saponite and nontronite clay. Along with the chemistry of the solution, their colloidal shape contributes equally significantly to the non-settlement of these suspended clays. Flocculation of the dispersed clay particles will provide (a) for easy and effective separation of the clay material from the waste water and (b) more convenient options for water treatment (and subsequent redistribution) This study was aimed at contributing to a better understanding of the dynamic interactions in the No 7 Dam system to contribute towards identifying a suitable means/method for chemical flocculation of the clay particles. The individual components of the system (clays, water quality) and influx contributors (kimberlite and its leachate) were systematically characterized by means of X-Ray Diffraction, X-Ray Fluorescence, petrographic microscopy, electron microscopy, electrophoretic mobility and standard water- and soil quality analyses. The baseline quality of the Cullinan kimberlite leachate was obtained based on ASTM D5744 principles. It was found that adjusting the pH-level and ionic strength of the waste water to the critical coagulation point (cK) (as determined by electrophoretic mobility and batch jar experiments) automatically induced coagulation. Higher valence cations were displaced from pH dependent surface charge sites by proton adsorption. The resultant increased ionic strength, in combination with decreased thickness of the ionic double layer, was sufficient for the automatic initiation of high strength disordered face-face and edge-face bonds. During batch Jar tests, flocculation initiated within 4 minutes after the addition of HCl (0.5 M) and total sedimentation completed within 3 hours. The use of commercial flocculants might decrease the sedimentation time. As expected a significant increase in dissolved salt content of the clear supernatant was observed. No re-dispersion of the dried clay occurred. Throughout the study geochemical modeling was performed with PHREEQC software to identify/determine possible effective experimental conditions, minimizing experimental time and expenses. The program was also used to model outcomes of the possible water treatment options, indicated in literature as viable options for similar situations. These options can be tested to extend upon the current research. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Current climate models often predict fractional cloud cover on the basis of a diagnostic probability density function (PDF) describing the subgrid-scale variability of the total water specific humidity, qt, favouring schemes with limited complexity. Standard shapes are uniform or triangular PDFs the width of which is assumed to scale with the gridbox mean qt or the grid-box mean saturation specific humidity, qs. In this study, the qt variability is analysed from large-eddy simulations for two stratocumulus, two shallow cumulus, and one deep convective cases. We find that in most cases, triangles are a better approximation to the simulated PDFs than uniform distributions. In two of the 24 slices examined, the actual distributions were so strongly skewed that the simple symmetric shapes could not capture the PDF at all. The distribution width for either shape scales acceptably well with both the mean value of qt and qs, the former being a slightly better choice. The qt variance is underestimated by the fitted PDFs, but overestimated by the existing parameterisations. While the cloud fraction is in general relatively well diagnosed from fitted or parameterised uniform or triangular PDFs, it fails to capture cases with small partial cloudiness, and in 10 – 30% of the cases misdiagnoses clouds in clear skies or vice-versa. The results suggest choosing a parameterisation with a triangular shape, where the distribution width would scale with the grid-box mean qt using a scaling factor of 0.076. This, however, is subject to the caveat that the reference simulations examined here were partly for rather small domains and driven by idealised boundary conditions.

Thesis (DPhil)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Freshwater is the most fundamental of all life-supporting resources that determine our social, economic and political wellbeing. It is, however, only a small percentage of the world's water resources and is also unevenly distributed. Arid regions make-up about forty percent of the world's land area and have a large proportion of the world population, however, they only have a small fraction of the freshwater compared to other areas. Conventional freshwater sources in arid environments such as surface water in rivers, lakes and dams are often seasonal, available mainly during the rainy season. Equally, only a small part of the rain (0 - 5% of rainfall) infiltrates into groundwater reserves, and even this groundwater displays high rates of salinisation such that the end-water is too saline for human consumption. The poor quality of groundwater in arid regions is generally understood, however, it is always assumed that this is mainly a problem in areas where surface water does not occur. The study investigates seasonal groundwater salinisation in ephemeral (seasonal) river sources in some parts of Namibia and aims to derive a better understanding of the nature of this problem and how it affects people in these areas. It also looks at some possible solutions to the problem with the aim of informing water managers and scientists who are responsible for formulating solutions for water supply to areas in arid regions. These solutions are designed to take advantage of available opportunities in the study areas namely; the abundant supply of solar energy, alternative sources of freshwater such as fog and general atmospheric moisture, and adaptations for water collection in animals that inhabit these regions. The results show that groundwater in shallow ephemeral river sources of the Namib Desert and the Cuvelai delta in North central Namibia display high seasonal variation in Total Dissolved Solids (TDS) and chemical composition. The lowest TDS values are recorded during the rainy season, mainly after the first rains in the high rainfall areas and only after flood events in the lower rainfall regions. The groundwater salinity increases during the remainder of the year and in most cases becomes too saline for drinking purposes. The investigations of possible solutions indicate that small-scale photovoltaic reverse osmosis; solar distillation and fog collection could be used to address the seasonal shortage of potable water in these areas. The low-pressure (6 bar) reverse osmosis desalination experiments show that it is possible to operate the unit on a solar-driven pump to produce enough water to cover the typical daily water demand of a village in the Namib Desert. This unit would produce about 4600 litres per day (l/day) of 500- mg/l TDS product water, which exceeds the water production of similar world-leading small-scale RO units in Australia and The Canary Islands. The results also show that the cost of solar distillation units (solar stills) can be reduced sufficiently to make them a viable option for water supply to individual households in these rural areas. The study also found that fog is a feasible alternative source of freshwater in some of the study areas. The fog water is generally of 'A' quality drinking water according to the WHO-derived Namibian Drinking Water Quality Guidelines (NDWQG) and can be used directly or mixed with the saline groundwater to provide potable water. Mixing of the above-mentioned waters is particularly suitable in the Central Namib Desert because the period of high groundwater salinity coincides with that of peak fog deposition. The results also show that fog water can be collected with vanous polymeric greenhouse shade netting that can be easily obtained, and provides guidelines on the correct percentage shade coefficient and weave of possible fog collector mesh to intending users of fog collection technology in areas where the polypropylene mesh that is used in Standard Fog Collectors is not available. The investigations of surface properties of fog-harvesting beetles and experiments with various prototype collectors show that it is possible to increase water production in fog collectors existing today. The hydrophobic surface conditions as were found on the cuticles of fog-basking beetles (Onymaeris unguicularis and Onymacris bieolor) would enhance formation and runoff of large fog droplets on the collector surface. The prototype extractor-fan- and cooling system-based collectors show that it is possible to increase fog collection on polymeric meshes about three times and also that a comparable volume of atmospheric moisture can be collected even when there is no fog, up to a relative humidity of about 40%. In conclusion the study emphasizes that groundwater salinity in arid regions is at times a seasonal problem that should be considered in water supply strategies for these regions. Also that atmospheric moisture is a feasible alternative source of freshwater in some arid regions that often exceeds rainfall several times and should be considered as an important aspect of the strategies to address water problems in these areas. The study strongly recommends that scientists, engineers and water managers in these regions should always investigate the available opportunities such as climatic conditions (e.g. fog deposition) and adaptations for water collection/conservation that are found in the endemic plants and animals in order to develop sustainable solutions to this problem. They should also constantly update themselves on developments/opportunities that arise in the larger water industry that could be of benefit to water supply initiatives for remote areas in developing countries. Lastly, the study serves to better the understanding of the nature of groundwater salinity in arid environments that are dependent on seasonal surface flow for water supply as well as to contribute to the formulation of solutions to this problem in these areas, particularly in west coast hyper arid environments where conventional sources of freshwater are most inadequate. It also emphasises the role of materials science (polymers) and environmental engineering as well as that of UNESCO associated scientific institutions in the formulation of sustainable solutions to some of the current water problems in arid regions. Keywords: Arid lands, hydrochemistry, sources of freshwater, desalination, atmospheric moisture / AFRIKAANSE OPSOMMING: Vars water is die mees fundamentele van aIle lewensonderhoudende natuurlike hulpbronne wat ons sosiale, ekonomiese, en politieke welstand bepaal. Dit is egter slegs 'n klein gedeelte van die totale waterbronne van die wereld, en is boonop baie oneweredig versprei. Natuurlike waterarm gebiede (woestyne en halfwoestyne) beslaan ongeveer veertig persent van die landoppervlakte van die aarde en word bewoon deur 'n relatief groot persentasie van die wereldbevolking, maar beskik oor slegs 'n klein gedeelte van die varswater in vergelyking met ander gebiede. Konvensionele bronne van varswater in waterarm gebiede, soos oppervlaktewater in riviere, mere en darnme, is dikwels seisoenaal, en slegs beskikbaar gedurende die reenseisoen. Verder beland slegs 'n klein gedeelte van die reenval (0 - 5%) in die ondergrondse waterreserwes, en selfs hierdie grondwater vertoon 'n hoe mate van versouting, sodat die eindproduk te brak is vir menslike gebruik. Die swak gehalte van grondwater in waterarm gebiede word algemeen verstaan, maar daar is tot nog toe aanvaar dat dit oor die algemeen slegs 'n probleem is in gebiede waar oppervlaktewater me voorkom nie. Hierdie studie ondersoek seisoenale grondwaterverbrakking in seisoenale rivierbronne in sekere dele van Namibie en beoog om 'n beter begrip te formuleer van die aard van die probleem en hoe dit die inwoners van hierdie gebiede raak. Daar word ook ondersoek ingestel na moontlike oplossings vir die probleem, met die doel om 'n inligtingsbron vir waterbestuurders en wetenskaplikes wat verantwoordelik is vir die formuleer van oplossings vir watervoorsiening in waterarm gebiede daar te stel. Hierdie oplossings is ontwerp om voordeel te trek uit die beskikbare geleenthede in die ondersoekgebiede, naamlik; die oorvloedige beskikbaarheid van sonenergie, altematiewe bronne van varswater soos mis (Eng. "fog") en atmosferiese vog in die algemeen en aanpassings (Eng. "adaptations") vir die opvang van water wat voorkom by diere, veral insekte, in hierdie gebiede. Die resultate toon dat grondwater in die vlak seisoenale rivierbronne van die Namibwoestyn en die Cuvelai-delta in noordsentraal Namibie hoe seisoenale variasie in totale opgeloste stowwe (TVS) en chemiese samestelling vertoon. Die laagste TVS-waardes word waargeneem tydens die reenseisoen, hoofsaaklik na die eerste reen in die hoe-reenvalgebiede en eers na vloede in die lae-reenvalgebiede, Die soutgehalte van die grondwater neem toe gedurende die res van die jaar en in die meeste gevalle verbrak die water tot ondrinkbare vlakke. Die ondersoek na moontlike oplossings dui aan dat kleinskaalse fotovoltaiesgedrewe tru-osmose, sondistillasie en die opvang van mis (Eng."fog collection") aangewend kan word om die seisoenale tekort aan drinkwater in hierdie gebiede aan te spreek. Die laedruk (6 bar) tru-osmose-ontsoutingseksperimente wys dat dit moontlik is om die eenheid met behulp van 'n sonkraggedrewe pomp te bedryf en voldoende water te lewer vir die tipiese daaglikse drinkwaterbehoeftes van 'n nedersetting in die Namibwoestyn. Hierdie eenheid sal sowat 4600 liter per dag (l/d) water, met 'n TVSwaarde van 500 mg/I, lewer. Dit is aansienlik meer as die lewering van soortgelyke eenhede in Australie en die Kanariese Eilande. Die resultate wys ook dat die koste van sondistillasie-eenhede genoegsaam verminder kan word om dit 'n lewensvatbare opsie vir watervoorsiening aan enkelhuishoudings in die plattelandse gebiede te maak. Die studie het ook bevind dat die opvang van mis 'n toepaslike alternatiewe bron van varswater is in sekere van die studiegebiede. Die miswater is oor die algemeen 'A' -gehalte drinkwater vol gens die Namibiese gehalteriglyne Vir drinkwater (gebasseer op bepalings van die Wereldgesondheidsorganisasie) en dat dit net so, of vermeng met brak grondwater, gebruik kan word as drinkwater. Vermenging is besonder geskik in die sentrale Namibwoestyn, aangesien die periode van hoe grondwaterverbrakking saamval met die piek van benutbare misneerslag. Die resultate toon ook aan dat miswater opgevang kan word met verskeie tipes polimeriese skadunet, wat maklik verkrygbaar is, en verskaf riglyne vir die optimale skadu-koeffisient en weefpatroon van moontlike misvangsnette vir voomemende gebruikers van misvangstegnologie in gebiede waar die polipropileennet wat in die standaard miskollekteerders gebruik word nie, beskikbaar is nie. Die ondersoek van oppervlakeienskappe van mis-koesterkewers (Eng. "fog harvesting beetles") en eksperimente met verskeie prototipe versamelaars toon dat dit moontlik is om die waterproduksie van bestaande kollekteerders te verhoog. Die hidrofobe oppervlaktetoestande soos gevind op die opperhuid van die mis-koesterkewers (Onymacris unguicularis en Onymacris bicolor) bevorder die vorming en afloop van groot misdruppels op die versameloppervlak. Die prototipe suigwaaier- en verkoelerstelselgebasseerde versamelaars toon dat dit moontlik is om die misvogversameling op polimeriese nette tot drie maal te verhoog en dat 'n vergelykbare volume atmosferiese vog versamel kan word, selfs in die afwesigheid van mis, tot by 'n relatiewe humiditeit van ongeveer 40%. Ten slotte benadruk die studie dat grondwatersoutgehalte in waterann gebiede soms 'n seisoenale probleem is, en dat dit in ag geneem moet word in watervoorsieningstrategiee vir sulke gebiede. Dit benadruk ook dat atmosferiese vog 'n bruikbare alternatiewe bron van varswater kan wees in sekere areas, waar dit dikwels verskeie male meer is as reenval, en gesien behoort te word as 'n belangrike aspek in strategiee om waterprobleme in hierdie gebiede aan te spreek. Die studie beveel sterk aan dat wetenskaplikes, ingenieurs en waterbestuurders in hierdie gebiede altyd die beskikbare geleenthede soos klimaatstoestande (bv. misneerslag) en aanpassings vir vogvangslbewaring wat voorkom by inheemse plante en diere sal navors om sodoende onderhoudbare oplossings vir die probleem te vind. Hulle behoort deurlopend op hoogte te bly met ontwikkelings/geleenthede wat ontstaan in die wyer waterindustrie, wat van waarde kan wees in by waterverskaffmgsinisiatiewe vir afgelee gebiede in ontwikkelende lande. Laastens dien die studie om 'n beter begrip daar te stel van die aard van grondwatersoutvlakke in waterarm gebiede wat afhanklik is van seisoenale oppervlaktevloei vir watervoorsiening sowel as om 'n bydrae te lewer tot die formuleer van oplossings tot die probleem in hierdie gebiede, veral in die hiperdroe omgewings aan die Namibiese weskus, waar konvensionele waterbronne mees onvoldoende is. Dit benadruk ook die rol van materiaalkundige wetenskappe (polimere) en omgewingsingenieurswese sowel as die UNESCO-geassosieerde wetenskaplike instellings in die formulering van volhoubare oplossings vir sommige van die huidige waterprobleme in waterann gebiede. Sleutelwoorde: Waterarm gebiede, hidrochemie, bronne van varswater, ontsouting, atmosferiese vog

No description available.

Syfte: Idag riskerar cirka 300 000 hushåll med uteluftsventilerad krypgrund att bli angripna av fukt- och mögelskador. Klimatet i en uteluftsventilerad krypgrund påverkas i stor grad av temperaturen och den relativa luftfuktigheten. Det råder inga tvivel om att klimatet står inför förändringar, vilket innebär en höjd temperatur och en förändring av den relativa luftfuktigheten. Detta gör att den uteluftsventilerade krypgrunden inte har möjlighet att torka ut under vissa perioder på året och utsätts då för en förhöjd risk av fuktskador. Parallellt med klimatförändringen moderniseras även uppvärmningssystemen i småhusen, vilket ändrar förutsättningar för krypgrunderna. Målet med arbetet är att undersöka om klimatförändringarna och installation av golvvärme i träbjälklaget har bidragit till fuktskador i uteluftsventilerade krypgrunder och ge underlag till effektivare åtgärder av fuktskador. Metod: För att utreda om klimatförändringarna är ett problem för de uteluftsventilerade krypgrunderna har dokumentanalyser genomförts vilka sedan följdes av beräkningar av krypgrundens relativa luftfuktighet. På samma sätt gavs svar på om golvvärmen är en bidragande faktor till fuktskadorna. Båda frågeställningarna styrktes även av kvalitativa intervjuer med sakkunniga personer. Hur fuktskadorna effektivare kunde åtgärdas togs främst fram genom kvalitativa intervjuer men styrktes av dokumentanalyser. Resultat: Studien visar att klimatförändringarna kommer att påverka uteluftsventilerade krypgrunder i positiv bemärkelse då studien endast tog hänsyn till temperaturhöjningen. Installation av golvvärme har även visats vara positivt mot fuktskador i en uteluftsventilerad krypgrund om isolering i bjälklaget saknas eller är bristfällig. Branschen ser ingen vinst i att effektivisera åtgärdsmetoderna då dessa redan är välprövade och väl fungerande. Konsekvenser: Ett varmare klimat ger bättre förutsättningar för en uteluftsventilerad krypgrund. Medvetenheten om hur klimatförändringarna påverkar krypgrunderna ger byggbranschen ett försprång att förbereda sig inför kommande förändringar. Kunskapen om att golvvärme kan ge positiva effekter mot fuktskador i uteluftsventilerade krypgrunder ger nya förutsättningar för renoveringar och åtgärder mot fuktskador, dock måste energiförlusterna tas i hänsyn i dessa fall. Branschen ser ingen vinst i att effektivisera åtgärdsmetoderna, vilket gör att det inte finns någon anledning att gå djupare in i detta. Begränsningar: Arbetet behandlar endast uteluftsventilerade krypgrunder med träbjälklag som ligger inom Sveriges gränser. Denna studie är därför inte applicerbar på andra konstruktioner eller utanför Sveriges gränser. Endast klimatförändringarna det senaste seklet och fram till 2100 tas hänsyn till i rapporten. Studien tar heller inte hänsyn till fukttillskott från mark och dagvatten, likaså görs inga beräkningar på ventilation. / Purpose: Today are about 300 000 buildings with outdoor ventilated crawl space at risk to be contaminated by moisture and mold damage. An outdoor ventilated crawl space’s climate is greatly affected by the temperature and the relative humidity. There is no doubt that the climate is facing changes, which means an increased temperature and a change in the relative humidity. This prevents the outdoor ventilated crawl space from drying out during certain periods of the year and is then exposed to a heightened risk of moisture damage. Parallel to the climate change the heating systems are being modernized in houses, which changes the conditions for the crawl spaces. The objective of this essay is to do a research if climate change and the installation of underfloor heating in the greater part of the joist area has given rise to moisture damage in outdoor ventilated crawl spaces and provide good basis for more effective measures to moisture damage. Method: To investigate whether the climate change is a problem for outdoor ventilated crawl spaces have document analyzes been conducted, which was followed by calculations of the crawl spaces’ relative humidity. Calculations have been made to find out if the underfloor heating is a contributing problem to moisture damage. Both issues are also corroborated by interviews with qualified people. How the moisture damage more effective could be fixed was answered primarily through qualitative interviews, but corroborated by document analysis. Findings: The study shows that climate change will affect outdoor ventilated crawl spaces in a positive sense, only account to the temperature rise. Installing underfloor heating has also been shown to be positive against moisture damage in outdoor ventilated crawl spaces if insulation in the soffit is missing or deficient. The industry sees no gain in efficiency action methods as these are already proven and well- functioning. Implications: A warmer climate provides better conditions for outdoor ventilated crawl space. Being aware of the changes associated with climate change, and its effects on buildings give the construction industry a head start to prepare for future changes. Knowledge that underfloor heating can provide positive effects against moisture damage in crawl spaces creates new opportunities for renovations and actions against dampness but the energy losses in this case must be considered. Since the industry does not see profit in streamlining action methods is no need to go deeper into this. Limitations: The report deals only outdoor ventilated crawl spaces with wooden soffit that is located within the Swedish borders. This study is therefore not applicable to other constructions or other countries. Only climate change in the last century and up until 2100 are taken into account in the report. Further on the study does not take the excess moisture from the soil or the storm water into account; likewise there are no calculations for the ventilation.

Le travail abordé dans le cadre de cette thèse constitue une contribution à la compréhension des mécanismes d'endommagement et à l'identification d'un critère de durée de vie du polyamide 6,6 renforcé à 30% en masse de fibres de verre courtes (PA66GF30), obtenu par moulage par injection, en prenant en compte les effets de la température, de la teneur en eau et des orientations de fibres induites par le procédé de fabrication. Ainsi, dans un premier temps, une campagne d'essais de caractérisation du comportement mécanique du PA66GF30, pour différentes orientations de fibres, températures, teneurs en eau et vitesses de sollicitation, a été menée. Ceux-ci ont mis en évidence le rôle de la matrice polyamide 6,6 (PA66) dans la dépendance à la température, à la teneur en eau et à la vitesse de sollicitation du comportement du PA66GF30. Dans ce sens, une triple équivalence Temps-Température-Teneur en eau du comportement du PA66 a été démontrée à l'aide de courbes maîtresses obtenues par DMA. Une nouvelle expression de la vitesse équivalente à une température et une teneur en eau de référence en a alors été déduite, dans l'objectif de pouvoir rendre compte de cette triple sensibilité dans un futur modèle de comportement. Ensuite, une campagne d'essais de fatigue dans des conditions environnementales contrôlées, a permis d'étudier les effets de l'orientation des fibres, de la température et de la teneur en eau, sur la tenue en fatigue d'éprouvettes en PA66GF30. L'analyse mécanique de ces essais a abouti à l'identification d'un critère de durée de vie, tenant compte de l'ensemble des facteurs influents. Enfin, la microtomographie des rayons X sous faisceau synchrotron a été utilisée pour étudier les mécanismes d'endommagement en fatigue présents dans le PA66GF30, suite à des analyses post-mortem et des expériences in-situ. Le dépouillement de ces observations a permis de faire la lumière sur les mécanismes d'endommagement, et de proposer un nouveau scénario d'endommagement en fatigue. / The work discussed in this thesis is a contribution to the understanding of damage mechanisms and identifying a fatigue criterion of polyamide 6,6 reinforced with 30 wt% of short glass-fibres (PA66GF30), obtained by injection molding, taking into account the effects of temperature, water content and fiber orientations induced by the process. Thus, in a first step, the characterization of the mechanical behavior of PA66GF30 for different fiber orientations, temperatures, moisture contents and strain rates, was conducted. They have highlighted the role of the polyamide matrix (PA66) in the temperature, water content and strain rate behavior dependence of PA66GF30. In this sense, Time-Temperature-Water content equivalence of mechanical behaviour of PA66 was demonstrated using master curves obtained by DMA. A new expression of the equivalent strain rate at temperature reference and a water content reference was then deduced, and it is now possible to relay the triple sensitivity to strain rate, temperature and water content in only one term. Then, a fatigue test campaign in controlled environmental conditions, allowed to study the effects of fiber orientation, temperature and water content on the fatigue behaviour of PA66GF30 specimens. The mechanical analysis of these tests has led to the identification of a fatigue life criterion, taking into account all the influencing factors. Finally, the X-ray microtomography under synchrotron beam was used to study the mechanisms in fatigue damage present in the PA66GF30, following post-mortem analysis and in-situ experiments. The analysis of these observations has shed light on the mechanisms damage and, it has been proposed a new fatigue damage scenario.

La technologie d’identification radiofréquence (RFID) se décline aujourd’hui dans des milliers d’applications. Parmi elles nous pouvons citer les applications de gestion logistique des palettes/cartons dans les entrepôts industriels (RFID UHF) ainsi que l’identification des abonnés dans les réseaux de transports urbains (RFID HF). Depuis quelques années, des contributions scientifiques autour des technologies d’identification radiofréquence (RFID) avec un couplage capteur sont de plus en plus visibles. L’intérêt grandissant pour ce type de technologie s’appuie sur la possibilité d’une utilisation en masse de capteurs bon marchés pouvant être intégrés sur chaque objet. On parle alors d’objet connecté ou d’internet des objets (IoT). Dans cette thèse, nous nous focalisons sur l’étude et le développement d’un capteur RFID passif fonctionnant en bande UHF. Cette orientation technologique est dictée par l’application visée, l’agro-alimentaire, qui requiert des coûts de fabrication les plus faibles possibles et une distance de lecture supérieure au mètre. Pour l’élément sensible, nous utilisons un bio-polymère, plus précisément le gluten de blé dont les propriétés diélectriques en fonction de l’humidité relative ont été étudiées précédemment. Nous nous attachons à traiter toutes les problématiques liées à la communication entre un lecteur et un capteur RFID passif, l’objectif ultime de cette thèse étant de récupérer une information capteur à l’aide d’un lecteur RFID conventionnel respectant les standards du domaine et les directives radio en vigueur dans les différentes régions du monde. Pour valider cette étude, nous mettons en œuvre des capteurs-RFID pour réaliser un démonstrateur d’emballage « intelligent » permettant le suivi de la qualité des aliments. / Radio frequency identification (RFID) technology is available today in thousands of applications. Among them we can mention the logistics management applications pallets / cardboard in industrial warehouses (RFID UHF) and the identification of subscribers in urban transport networks (RFID HF). In recent years, scientific contributions around the radio frequency identification (RFID) technologies with a sensor coupling are increasingly visible. The growing interest in this type of development rely heavily on a mass use of inexpensive sensors that can be integrated on each object.It is calledconnected objects or Internet of Things (IoT). In this thesis, we focus on the study and development of a passive RFID sensor operating in UHF band. This technological orientation is dictated by the targeted application, the food industry, which requires the lowest possible manufacturing costs and a reading distance greater than one meter. For the sensitive element, we use a biopolymer, specifically wheat gluten whose dielectric properties as a function of relative humidity have been studied previously. We are committed to dealing with all the issues related to the communication between a reader and a passive RFID sensor, the ultimate objective of this thesis being to get a sensor information using a conventional RFID reader complying with the standards and the radio directives imposed in different regions of the world. To validate this study, we are implementing RFID sensors to create a smart packaging demonstrator for monitoring the quality of food.