This diploma thesis deals with maintaining possibilities for appropriate climatic conditions in outdoor greenhouse. The importance for growing plants is an appropriate temperature, humidity and adequate supply of water. The aim of the study is to suggest an apparatus sustaining beforehand defined conditions in the greenhouse with minimal requirements for maintenance. Apparatus uses analogue control by applying photosezistor and thermistor. For power supply are DC-DC converters used.

Les systèmes géothermiques de surface extraient l’énergie du sol via un fluide caloporteur circulant dans un échangeur pour une profondeur ne dépassant pas 200 m. Deux typologies d’échangeurs sont généralement utilisées : les systèmes avec échangeurs verticaux, principalement affectés par les conditions géologiques ; et les échangeurs horizontaux, plus proches de la surface du sol, impactés essentiellement par les conditions climatiques. Dans le sol, les échanges thermiques sont majoritairement des transferts de chaleur par conduction. Ainsi, les propriétés thermo-physiques du sol influencent la quantité d’énergie extraite par les échangeurs. Afin de quantifier les propriétés thermo-physiques d’un sol sous l’influence des conditions géologiques et climatiques, deux dispositifs expérimentaux sont élaborés, conçus, instrumentés et validés au sein de notre laboratoire. Les résultats expérimentaux enrichissent les connaissances scientifiques sur le comportement hydrique d’un sol soumis à des événements pluvieux et l’impact de la contrainte verticale sur les propriétés thermo-physiques d’un sol. De plus, une étude numérique, à partir d’une modélisation 2D par éléments finis d’un échangeur airsol, évalue les performances énergétiques de ce dernier en fonction de différentes humidifications du sol et différents scénarios de pluie. Les résultats numériques révèlent ainsi l’intérêt d’utiliser un sol d’enrobage très humide pour accroître significativement les performances énergétiques d’un échangeur air-sol. / Surface geothermal systems extract energy from the ground via a fluid circulating in an exchanger at a depth not exceeding 200 m. Two typologies of exchangers are generally used: systems with vertical exchangers, mainly affected by geological conditions; and horizontal exchangers, closer to the surface of ground, impacted mainly by weather conditions. Thermal exchanges in the soil are mainly conduction heat transfers. Thus, thermo-physical properties of soil influence, mostly, energy extracted by exchangers. In order to quantify influence of geological and meteorological conditions on thermo-physical properties of soil, two experimental devices are developed, designed, instrumented and validated. The experimental results provide more appropriate scientific knowledge on hydric behavior of a soil subjected to rain events and influence of compactness on thermal properties of soil. In addition, one numerical study, based on a finite element 2D modeling of an earth-air heat exchanger, evaluates their energy performance under different soil moisture conditions and rain scenarios thus revealing the utility of water to significantly improve its performance.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-22T18:03:39Z No. of bitstreams: 1 FRANCISCO DE ASSIS DA SILVA - DISSERTAÇÃO - PPGHT - 2017.pdf: 821237 bytes, checksum: 42afa05681517bd46df4caf1b3274a96 (MD5) / Made available in DSpace on 2018-05-22T18:03:39Z (GMT). No. of bitstreams: 1 FRANCISCO DE ASSIS DA SILVA - DISSERTAÇÃO - PPGHT - 2017.pdf: 821237 bytes, checksum: 42afa05681517bd46df4caf1b3274a96 (MD5) Previous issue date: 2017-10-19 / Um dos maiores gargalos encontrado pelos produtores de hortaliças folhosas na região semiárida, são os fatores climáticos, como temperatura e luminosidade excessiva, fazendo com que a cultura da alface não se desenvolva de forma eficaz, com isso, faz-se necessário criar alternativas capazes de atenuar esse estrese causado as plantas. Deste modo, foi conduzido um experimento em uma área experimental da Universidade Federal de Campina Grande, no Centro de Ciências e Tecnologia Agroalimentar UFCG/CCTA, de abril a junho de 2017, com objetivo de avaliar o crescimento e a produção de plantas da alface sombreada com diferentes cores de agrotêxtil e cobertura do solo com mulching nas condições edafoclimáticas do município de Pombal-PB. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas do tipo 5x2. A parcela foi composta pelas cores de agrotêxtil com gramatura de 15 g.m2 (lilás, branca, verde e amarela e cultivo a céu aberto) e a subparcela composta pela cobertura do solo (com e sem mulching). Por ocasião da colheita avaliou-se, altura de plantas e diâmetro de plantas, comprimento do caule e da raiz, diâmetro do caule, número de folhas por planta, massa seca de raiz, caule, folha, parte aérea e total, massa fresca da parte aérea e produtividade. O agrotêxtil de cor lilás e amarela apresentaram incrementos na fitomassa e produção da alface. Para as características de partição de massa na planta, as telas de cor lilás e amarela se destacaram em relação às demais apresentando assim as melhores médias. Para cobertura do solo com mulching, observou-se que as plantas que foram cultivadas em canteiros sem a presença do mulching apresentaram melhores médias para as variáveis estudadas. Deste modo, foi observado que a plantas desenvolveram-se melhor com o auxílio do sombreamento quando comparado com o tratamento controle (testemunha) o cultivo a céu aberto. A utilização do mulching como cobertura do solo nas condições do estudo diminuiu o crescimento e consequentemente a produção da alface. / One of the biggest bottlenecks found by leafy vegetable growers in the semi-arid region is the climatic factors, such as temperature and excessive luminosity, so that lettuce culture does not develop efficiently, so it is necessary to create alternatives capable of plants. Thus, an experiment was conducted in an experimental area of the Federal University of Campina Grande, UFCG / CCTA in Center of Science and Agro-food Technology , from April to June 2017, with the objective of evaluating the growth and production of shaded lettuce with different colors of agrotêxtil and mulching in the soil and climatic conditions of the city of Pombal-PB. The experimental design was a randomized block with subdivided plots of type 5x2. The plot consisted of the agrotêxtil colors with a grammage of 15 g.m2 (lilac, white, green and yellow and open cultivation) and the subplot composed by the soil cover (with and without mulching). Plant height and diameter, root and stem length, stem diameter, number of leaves per plant, root dry mass, stem, leaf, shoot and total mass, fresh mass of shoot and productivity. The agrotêxtil of lilac and yellow color presented increases in the phytomass and lettuce production. For the mass partition characteristics in the plant, the lilac and yellow color screens stood out in relation to the others, thus presenting the best averages. For soil cover with mulching, it was observed that the plants that were cultivated in beds without the presence of mulching presented better means for the studied variables. Thus, it was observed that the plants were better developed with the aid of shading when compared to the control treatment (control) the cultivation in the open. The use of mulching as a soil cover under the study conditions decreased the growth and consequently the lettuce production.

No description available.

Windblown dust remains a persistent problem within South African urban and peri-urban areas due to the prevailing dry climatic conditions, extensive surface mining and mineral processing. Despite deposition monitoring guidelines and national dust regulations, South Africa still has persistent dust problems in especially gold mining districts. The main aim of the research is to critically evaluate all the potential challenges within dust management which could be responsible for persistent dust problems within gold mining regions of South Africa. The research methodology included a literature review to provide important information regarding the requirements for successful dust management internationally. Data were gathered by using the survey method through questionnaires and interviews as this type of survey method allows for descriptive reporting where respondents provide information on their attitudes and perceptions. In total 37 questionnaires were distributed among two district municipalities, seven gold mining companies, ten interested and affected parties including two non-governmental organizations, as well as five specialists. A total response rate of 81.1 % was achieved. The results of the questionnaires revealed that the most significant challenges to dust management within gold mining regions of South Africa are the following: monitoring networks; monitoring methods; deposition standards; financial provisions; technical skills and capacity; lack of specific dust management plans within air quality management plans; limited regulation and enforcement; limited information and participation of government, lack of participation of interested and affected parties as well as specialists‟ expertise. All the challenges identified were then successfully linked back to the referenced literature from which the challenges were initially derived. The main aim of this research was thus successfully completed by initially identifying the challenges facing dust management within gold mining regions of South Africa and then critically evaluating them and making recommendations. / M. Environmental Management, North-West University, Potchefstroom Campus, 2014

Aero-terestric algae occure on a wide range of substrates, such as soil, plant, stone and rock surfaces and also on a variety of anthropogenic substrates. Morphological convergence towards coccoid or filamentous thalli, caused by frequent dessication stress, is typical for this group. Algae are frequently used for biomonitoring of various biotopes, mostly water biotopes, but also for bioindication of air quality. My diploma thesis is based on a study of autotrophic microbial growths on spruce and yew needles in relation to various air quality measures evaluating air pollution of sites. The results show that the occurence of microbial growths on needles is primarily influenced by the orientation towards cardinal points. However, the air pollution factors also proved to be significantly related to the quantitative measures of the microbial assemblages. Among them, the relative proportion of algae in microbial growths was the most tightly related to air pollution.

<p>Tokom tri vegetacione sezone mereni su fiziolo&scaron;ki<br />parametri: fotosinteza, transpiracija,&nbsp; efikasnost<br />iskori&scaron;tavanja&nbsp; vode (WUE), kao i parametri<br />bioprodukcije na odabranim &scaron;umskim<br />populacijama bukve&nbsp; (Fagus sylvatica&nbsp; L.), smrče<br />(Picea abies (L.) Kartsen) i jele (Abies alba Mill.),<br />čija su stani&scaron;ta na različitim nadmorskim visinama<br />sa različitom&nbsp; dostupno&scaron;ću vode u zemlji&scaron;tu.<br />Određivana je i zavisnost između položaja &scaron;umske<br />zajednice na padini planine (nadmorska visina i<br />nagib) i fotosinteze, odnosno bioprodukcije<br />biljaka. Cilj istraživanja je bio da se precizno<br />defini&scaron;e mogući dalji trend geografskog<br />pomeranja stani&scaron;ta odabranih biljnih vrsta koji je u<br />korelaciji sa morfo-fiziolo&scaron;kim&nbsp; adaptivnim<br />odgovorom biljaka na promenu ekolo&scaron;kih uslova<br />životne sredine.&nbsp; Fotosintetička aktivnost tokom<br />vegetacione sezone bila je stabilna ili se<br />povećavala pri optimalnoj vlažnosti zemlji&scaron;ta. Na<br />lokalitetima Tara i Kopaonik količina<br />atmosferskih padavina nije igrala određujuću<br />ulogu u dinamici fotosintetičke asimilacije CO₂.<br />Vlažnost zemlji&scaron;ta je na ovim lokalitetima bila<br />visoka i stabilna zbog dreniranja vode sa&nbsp; okolnih<br />brda. Registrovane razlike u dinamici fotosinteze<br />između ispitivanih vrsta povezane su sa različitim<br />životnim ciklusom listopadnih i četinarskih vrsta i<br />sa različitim fiziolo&scaron;kim adaptacionim<br />strategijama na promene faktora spolja&scaron;nje<br />sredine. Na dinamiku fotosintetičke asimilacije<br />CO_2&nbsp;signifikantno utiče prosečna temperatura<br />vazduha pre i tokom merenja, prosečna<br />osmonedeljna količina padavina pre merenja,<br />količina padavina na dan merenja, kao i<br />momentalna vlažnost zemlji&scaron;ta (MVZ). Rezultati<br />istraživanja ukazuju da će dejstvo klimatskih<br />promena biti vi&scaron;e izraženo na &scaron;umskim<br />populacijama koje se nalaze na&nbsp; vr&scaron;nim,<br />grebenskim lokalitetima većih nadmorskih visina,<br />ili na padinama planina. Su&scaron;ni periodi tokom<br />vegetacione sezone, značajan su faktor pomeranja<br />&scaron;uma planinskih lokaliteta. Bukove &scaron;ume su dobro<br />adaptirane na su&scaron;u i dobro podnose temperaturni<br />stres, međutim, dugi periodi sa oskudnim<br />padavinama izazivaju smanjenje asimilacije CO₂<br />&scaron;to ograničava značaj &scaron;uma u ublažavanju<br />klimatskih promena.</p> / <p>During three vegetation seasons,&nbsp; physiological<br />parameters, such as&nbsp; photosynthesis,&nbsp; transpiration,<br />water use efficiency&nbsp; (WUE), as well as the parameters<br />of bioproduction of the&nbsp; beech (Fagus&nbsp; sylvatica&nbsp; L.),<br />spruce (Picea&nbsp; abies&nbsp; (L.) Kartsen) and&nbsp; fir (Abies&nbsp; alba<br />Mill.)&nbsp; forest populations&nbsp; have&nbsp; been investigated<br />depending on different altitude&nbsp; mountain.&nbsp; The<br />relationship between&nbsp; the photosynthesis&nbsp; (and<br />bioproduction)&nbsp; of plants&nbsp; and the&nbsp; slope of the mountain<br />is&nbsp; also specified&nbsp; according to&nbsp; ecological parameters<br />(water&nbsp; regime and temperature.&nbsp; The aim of this<br />research is to define physiological status of forest<br />mountain ecosystems in relation to the ecological<br />conditions and predict further trend of geographic shift<br />of the habitats, which is in&nbsp; correlation with the&nbsp; plant<br />morpho-physiological adaptation responses on<br />environmental&nbsp; changes.&nbsp; Photosynthetic activity<br />during vegetation season was stable or increased&nbsp; in<br />optimal level of soil moisture&nbsp; conditions. On the<br />localities of Tara and Kopaonik the quantity of<br />atmospheric precipitation did not play a determining<br />role in the dynamics of photosynthetic assimilation of<br />CO₂. On these localities soil moisture was high and<br />stable as a result of water running off from<br />surrounding mountains.&nbsp; Detected differences in the<br />dynamics of photosynthesis of the tested species are<br />result of&nbsp; various lifecycles of&nbsp; deciduous and<br />coniferous trees and various physiological adaptation<br />strategies.&nbsp; The most influential effects on the<br />dynamics of the photosynthesis of the&nbsp; beech,&nbsp; spruce<br />and fir plants during the vegetation season were the<br />following abiotic factors: average air temperature<br />before measuring, temperature on the day of<br />measuring,&nbsp; eight-week amount of average<br />precipitation before measuring, amount of<br />precipitation&nbsp; on the day of measuring&nbsp; and&nbsp; soil<br />humidity. The analysis of the physiological parameters<br />of the beech populations of various mountain&nbsp; altitudes<br />show that even if beech is sensitive to draught it has<br />the physiological potential to keep its vitality by<br />efficient managing water.&nbsp; Effect of climatic changes<br />will be more expressed in forests that can be found on<br />high&nbsp; altitude mountain reefs and peaks.&nbsp; Beech forests<br />tolerate temperature&nbsp; and drought&nbsp; stress, but long<br />periods of&nbsp; poor&nbsp; precipitation&nbsp; cause the decrease of<br />CO_2&nbsp;assimilation which consequently decreases their<br />importance in the global reduction of atmospheric<br />CO₂,&nbsp;i.e. limits their role in the&nbsp; moderation&nbsp; of climate<br />change.</p>

The Eastern Cape Province of South Africa has climatic conditions which differ from region to region. The groundnut (Arachis hypogaea L.) cultivars, as it is the case with other crops, do not always perform equally well in the varying conditions. Abiotic stresses such as drought, extreme temperatures, and high soil acidity restrict plant growth. Lack of studies on adaptability of commercial groundnut cultivars in the Eastern Cape necessitated this study. Abiotic and biotic factors are not the only limiting factors: calcium availability in the soil is also a limiting factor in groundnut production. The aim of the study was to identify best suited cultivars for climatic conditions of Mthatha and Lusikisiki regions of the Eastern Cape. Two similar field experiments were conducted in the two locations with different climatic conditions. The results showed significant differences (P<0.05) in genotypes with respect to seed yield in both locations. Kwarts produced higher seed yield of 1155 kg ha-1 in Mthatha, while the same genotype produced low seed yield of 630 kg ha-1 in Lusikisiki location. In Lusikisiki the highest seed yield was recorded in Anel (936 kg ha-1) which produced low yield of 692 kg ha-1 in Mthatha. The genotypes that performed well in Mthatha in 2010/11 season included Kwarts, Nyanda, ICGV-SM 95714 and Mwenje. These genotypes were further used to investigate their response to calcium supplementation at flowering stage under conditions of Mthatha in the 2011/12 season. The results were significantly different for calcium absorption (P<0.05). Nyanda, Kwarts and Mwenje responded positively to calcium application at flowering stage producing relatively high yield of 153, 150 and 110 kg ha-1, respectively. Oil content was significantly increased by calcium application at flowering in Nyanda with 27.28% compared to 20.7% without Ca.

Windblown dust remains a persistent problem within South African urban and peri-urban areas due to the prevailing dry climatic conditions, extensive surface mining and mineral processing. Despite deposition monitoring guidelines and national dust regulations, South Africa still has persistent dust problems in especially gold mining districts. The main aim of the research is to critically evaluate all the potential challenges within dust management which could be responsible for persistent dust problems within gold mining regions of South Africa. The research methodology included a literature review to provide important information regarding the requirements for successful dust management internationally. Data were gathered by using the survey method through questionnaires and interviews as this type of survey method allows for descriptive reporting where respondents provide information on their attitudes and perceptions. In total 37 questionnaires were distributed among two district municipalities, seven gold mining companies, ten interested and affected parties including two non-governmental organizations, as well as five specialists. A total response rate of 81.1 % was achieved. The results of the questionnaires revealed that the most significant challenges to dust management within gold mining regions of South Africa are the following: monitoring networks; monitoring methods; deposition standards; financial provisions; technical skills and capacity; lack of specific dust management plans within air quality management plans; limited regulation and enforcement; limited information and participation of government, lack of participation of interested and affected parties as well as specialists‟ expertise. All the challenges identified were then successfully linked back to the referenced literature from which the challenges were initially derived. The main aim of this research was thus successfully completed by initially identifying the challenges facing dust management within gold mining regions of South Africa and then critically evaluating them and making recommendations. / M. Environmental Management, North-West University, Potchefstroom Campus, 2014

Les problématiques environnementales (conservation de l’environnement et lutte contre la pollution), économiques (demande d’énergie de plus en plus forte pour un développement socio-économique) et politiques (démocratisation de l’accès à l’énergie) mondiales actuelles imposent un changement de comportement en matière de consommation énergétiques afin de ne pas compromettre la qualité de vie des générations futures. A cette fin, l’utilisation des énergies renouvelables, dont l’énergie solaire photovoltaïque, se présente comme une des solutions les plus prometteuses. Néanmoins, du fait de leurs intermittences, il peut s’avérer nécessaire de recourir à des dispositifs de stockage de l’énergie. Ceux-ci sont généralement utilisés dans le cas des sites isolés du réseau électrique mais de plus en plus de travaux de recherches portent sur l’intégration d'unités de stockage dans les systèmes photovoltaïques connectés aux réseaux électriques (« intelligents »). La mise en œuvre des moyens de stockage ainsi permet d’optimiser la production et d’améliorer la rentabilité de l’électricité produite tout en permettant de lisser les appels en puissances de pointe du réseau. Pour les endroits difficilement accessibles, le stockage de l’électricité permet d’assurer une autonomie énergétique en ajustant la production aux besoins de consommation et inversement. Ceci entraine un processus continu de charges et décharges des unités de stockage qui peut modifier profondément les propriétés physico-chimiques et électriques des systèmes de stockage avec comme conséquence la réduction de la durée de fonctionnement de l’installation. Généralement, les caractéristiques techniques des unités de stockage sont déterminées par les constructeurs dans des conditions idéales de fonctionnement, notamment à courant et température constants. Aussi, lorsque le fonctionnement a lieu dans des conditions climatiques austères, telles que celles des pays du Sahel, la durée de vie réelle de ces systèmes peut s’avérer très différente des prévisions se basant sur les données du constructeur. Ces pays, grands gisements solaires, sont caractérisés par des sols arides et de grandes étendues désertiques. Il y fait très chaud et les populations sont clairsemées en petits hameaux, ce qui fait des systèmes photovoltaïques autonomes les meilleurs candidats pour satisfaire les besoins énergétiques. Pour un dimensionnement approprié et une mise en œuvre efficace, il est important de connaître le comportement des constituants du système dans les conditions climatiques des sites cibles. Il y a lieu en effet de connaître les impacts de celles-ci sur la durée de vie et les caractéristiques des composants, de déterminer le besoin éventuel de dispositifs de conditionnement et d’envisager les études scientifiques et techniques de leur mise en œuvre. Les travaux de recherche envisagés ont pour but de répondre à ces multiples questions en s'appuyant sur une plate-forme expérimentale et des modèles, et de produire à termes des outils informatiques d’aide à la décision / Environmental issues (environmental conservation and the fight against pollution), economic (energy demand increasingly high for socio-economic development) and political (democratic access to energy) current global impose a change in energy consumption-related behavior in order not to compromise the quality of life of future generations. To this end, the use of renewable energies, including solar PV, is as one of the most promising solutions. However, because of their intermittent, it may be necessary to use in energy storage devices. These are generally used in the case of isolated sites of the electricity grid but more and more research work focuses on the integration of storage units in photovoltaic systems connected to electricity networks ( "smart"). The implementation of the storage means and to optimize production and improve the profitability of electricity while enabling smooth network calls in peak powers.For hard to reach areas, the electricity storage ensures energy independence by adjusting production to consumer needs and vice versa. This causes a continuous process of charging and discharging of the storage units that can profoundly change the physicochemical properties and electrical storage systems with consequent reduction in operating life of the installation. Generally, the technical characteristics of storage units are determined by manufacturers under ideal operating conditions, including current and constant temperature. Also, when the operation takes place in austere weather conditions, such as those of the Sahel, the real life of these systems can be very different predictions based on the manufacturer. These countries, large solar fields, are characterized by arid soils and large stretches of desert very hot and the people he makes are scattered in small hamlets, making stand-alone photovoltaic systems the best candidates to meet energy needs. For proper design and effective implementation, it is important to know the behavior of the system components in the climatic conditions of the target sites. It must indeed know the impact of these on the life and characteristics of components, to determine the possible need for conditioning devices and consider the scientific and technical studies of their implementation. The proposed research aim to answer these many questions based on an experimental platform and models, and produce terms of IT tools for decision support