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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Automatic flush valve performance (gallons per flush) measured from fixtures in a mixed-use classroom/office building at Texas A&M University

Lertbannaphong, Salilla 29 August 2005 (has links)
Since water-use characteristics and the new technology of plumbing fixtures have changed, it is significant to educate a facility manager in the characteristics of these systems. Also, it is necessary to provide a better understanding of parameters that may determine the suitability of retrofitting plumbing fixtures. The 1992 Energy Policy Acts enforces 1.6-gallon per flush (gpf) for a toilet and 1.0 gpf for a urinal. In response to the regulation, the purpose of this research is to measure automatic flush valve performance (gpf) of fixtures in a mixed use classroom building at Texas A&M University. Water consumption (gpf) among three types of fixtures; low-consumption manual, old optic automatic and improved optic automatic systems are measured by using a magnetic water flow meter. The data in the study were analyzed to determine compliance with plumbing standards and to compare the average water volume per flush cycle of toilets in the men??s and women??s restrooms. Finally, the results of the data show that retrofitting the old optic automatic with the improved optic automatic system resulted in water savings of about 15.80% in toilets, and urinals.
2

Water relations and the control of flush growth in Theobroma cacao L

Robinson, A. W. January 1986 (has links)
No description available.
3

Separator Design for Use in High GVF Multiphase Flow

Cihak, Daniel 2012 August 1900 (has links)
The requirement of bringing an outside coolant source to run through the seals of a multiphase pump has always been a costly endeavor. Using a separator to extract liquid from the exhaust of the pump to use as a coolant is often more expensive than providing an outside source of coolant. This research proposes a cost effective separator design which efficiently separates the liquid from gas, while maintaining a high enough residence time to remove any gas entrainment, and separates only the seal flush requirement by letting any excess liquids carryover with the gas. Conventional multiphase separators operate by substantially decreasing the velocity of the mixture, which reduces the drag force put forth by the gasses and allows gravity to force the liquids downward. Gas-Liquid Cylindrical Cyclones (GLCCs) operate by increasing the velocity of the mixture, using radial force to separate liquids and gasses. This technique requires a smaller diameter vessel to achieve separation. The separator in this research uses gravity as the separation force while maintaining a pipe diameter similar to the GLCC. This way, only standard pipe and pipe fittings are used. The effectiveness of this design is measured two ways. First, efficiency is studied at varying gas volume fractions (GVFs), velocities, pressures, and pipe diameters. Second, the length of air entrainment (LAE) is measured at the same varying conditions. The efficiency and air entrainment studies provide design recommendations to accommodate seal flush requirements and size limitations. The following investigation also offers further areas of research to improve the understanding and modeling of using standard pipe and pipe fittings to create more effective design equations.
4

The influence of flush feeding with different nitrogen sources on ovulation and conception rates in Dohne-Merino ewes

Marais, Willem Jacobus 17 November 2011 (has links)
The aim of the present study was to determine if there is a difference in ovulation- and conception rates, in semiintensively managed Dohne-Merino ewes, flush fed with diets containing different nitrogen sources. Four different nitrogen sources were chosen due to the difference in dietary amino acid composition and cost. In order for a sheep farming enterprise to maximize profitability it is essential to optimize ovulation- and conception rates and to minimize lamb losses in order to increase weaning percentage and therefore profitability. However the cost of dietary supplementation is high and may increase production costs and minimize profitability. One hundred and fourty four (144) Dohne-Merino ewes (age between 14 to 85 months) were included in two dietary supplementation trials (autumn and summer) at the experimental farm of the University of Pretoria in Hatfield. The ewes were divided equally into two trial groups (n=72), with the first trial done in season 1 (started in May 2001, typical breeding season) and the second trial done in season 2 (started in November 2001, out of season; 2nd breeding season). During the day the ewes had ad-libitum access to graze on Festuca arundinaceace (Tall Fescue). In both trials the ewes (n=72) were randomly allocated into four dietary supplementation groups, each group receiving a dietary supplement with a different combination of nitrogen sources. The four dietary supplements were formulated on an iso-nitrogen basis, to eliminate the effect of protein level, and to emphasize the possible effect of protein quality (amino acid composition) on ovulation, conception and lambing rates. In both trials the total amount of crude protein intake per ewe was calculated at 256.40g/day, while the total daily allowance of digestible crude protein was calculated at 190g per ewe. The 256.40g crude protein intake per ewe per day is 2 times more than the threshold level of 125g per ewe per day. A minimum daily crude protein intake of 125g is needed for effective rumen functioning, and this together with the interconvertin of energy by the rumen indicates the complex nature of relating dietary differences to physiological responses. These values were kept the same for both the trials in season 1 and 2. The bulk of the 256.40g crude protein per day was obtained from grazing on the Festuca arundinaceace pasture. In season 1 the dietary supplement had to provide 40.00g of crude protein per day in order to get to a daily crude protein intake of 256.40g, while in season 2 the provision from the dietary supplement was calculated to be 37.45g of crude protein. The difference in the crude protein level, obtained from grazing of the Festuca arundinaceace between season 1 and 2 was due to pasture quality differences. The nitrogen sources used in the trials were urea, sunflower oilcake meal, cottonseed oilcake meal and a mixture of cottonseed oilcake meal and fishmeal. These dietary supplements were fed for a period of 9 days before mating; the weight of each ewe was recorded before the onset of the trial and again on the second day after mating to establish any live weight changes. Synchronization of the ewes was done with Chrono-gest grey sponges (40mg Fluorogestone acetate) from day one and was repeated from day 23. On day 12 each ewe were injected with 1.0ml prostaglandin F2α (Prosolvin,each milliliter containing 7.5mg Luprostiol). On day fourteen the sponges were removed and two days later all the ewes were checked for cyclic activity with the aid of six vasectomized rams. The six vasectomized rams were introduced to the whole laparoscopy group of 12 ewes, and every ewe that stood twice for mating were identified as cyclic. This practice continued for a period of 30 minutes in the morning and repeated for another 30 minutes in the afternoon up to day 18. The second round of sponges were inserted on day 23 and removed on day 37. Ewes were mated by means of hand mating with two different rams from day 39 to 42. A laparoscopy technique was used on day 45 of the trial to count the number of ovulation points (corpora lutea) on each ovarium of each ewe. The number of fetuses of each ewe was counted on day 90 after mating by means of ultrasound scanning and at birth the number of lambs born was also recorded. In both these trials dietary supplementation had no significant effect on ovulation, conception and lambing rates. However, looking at the Odds Ratio Analysis for the 144 ewes over the two breeding seasons, the different dietary supplements had a significant influence on the number of ovulation points (p<0.05). Compared to urea (dietary supplement 1), the fishmeal cottonseed oil cake mixture (dietary supplement 4) yielded the best results (1.306), followed by the cottonseed oil cake meal (dietary supplement 3) (1.298), and sunflower oil cake meal (dietary supplement 2) (1.050). The same Odds Ratio Analysis showed that the different dietary supplements had a significant effect on the number of lambs born (p<0.01). Compared to urea (dietary supplement 1), the fishmeal cottonseed oil cake mixture (dietary supplement 4) yielded better results (1.086), followed by urea (dietary supplement 1) (1.000), and sunflower oil cake meal (dietary supplement 2) (0.801) and lastly cottonseed oil cake meal (dietary supplement 3) (0.784). Breeding season (p<0.05) had a significant effect on the number of ovulation points but no difference was observed in terms of the number of lambs born. Age (p<0.01) had a significant effect on the number of ovulation points, the number of fetuses counted as well as the number of lambs born. Change in live weight (p<0.05) had a significant effect on the number of ovulation points per ewe but as with breeding season it had no significant effect on the number of lambs born. Birth status of a ewe (p<0.05), had a significant effect on the number of fetuses and the number of lambs born. The data of both the trials in season 1 and 2 suggests that under the conditions of the study with the odds ratio analyses that the four different dietary supplements had a significantly different effect compared to dietary supplement one on the number of ovulation points and the number of lambs born. However, factors like breeding season, age, change in live weight and birth status of the ewe also had a significant effect on ovulation and conception rates in Dohne-Merino ewes. / Dissertation (MSc(Agric))--University of Pretoria, 2011. / Animal and Wildlife Sciences / unrestricted
5

Caracterização da influência de cargas poluidoras difusas na qualidade da água no córrego Botafogo, Goiânia, Goiás / Characterization of the influence diffuse pollutant loads in water quality in the stream Botafogo, Goiânia, Goiás

Salgado, Aline de Arvelos 04 September 2013 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-31T13:15:14Z No. of bitstreams: 3 Dissertação - Aline de Arvelos Salgado - 2013 (1).pdf: 19133020 bytes, checksum: 99f7494b6d5b0c0afb94eb7523a14e81 (MD5) Dissertação - Aline de Arvelos Salgado - 2013(2).pdf: 9872700 bytes, checksum: f92f9ac233f9de3dc5f82ab719021535 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-31T13:50:45Z (GMT) No. of bitstreams: 3 Dissertação - Aline de Arvelos Salgado - 2013 (1).pdf: 19133020 bytes, checksum: 99f7494b6d5b0c0afb94eb7523a14e81 (MD5) Dissertação - Aline de Arvelos Salgado - 2013(2).pdf: 9872700 bytes, checksum: f92f9ac233f9de3dc5f82ab719021535 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-31T13:50:45Z (GMT). No. of bitstreams: 3 Dissertação - Aline de Arvelos Salgado - 2013 (1).pdf: 19133020 bytes, checksum: 99f7494b6d5b0c0afb94eb7523a14e81 (MD5) Dissertação - Aline de Arvelos Salgado - 2013(2).pdf: 9872700 bytes, checksum: f92f9ac233f9de3dc5f82ab719021535 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-09-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Accelerated urbanization and disorganized has caused many impacts on the environment, either by modifying the conditions of living and the quality of water resources. The present work aims to characterize the quality and quantity of water and pollutant loads from Botafogo stream, during the dry and rainy, through analysis of quality and quantity, in order to know the behavior of the water quality of the water body and provide impacts of runoff in the water body. During the dry season, nine monitoring were performed in eight sampling points and during the rainy season, only one point was rated 5 rainfall events. Analyses discriminatory (boxplot), cluster and correlation were essential to understand the variations of water quality in dry periods, demonstrating that monitoring in future there is the possibility of reducing the number of sampling points and parameters. It was observed that the parameters COD, BOD5, color, turbidity, coliforms and E.coli showed clear seasonal variation. In the five rain events was evaluated possible to see large fluctuations in concentration during the monitored parameters, especially coliforms and E.coli, suspended solids and turbidity, clearly demonstrating the impact of stormwater drainage on surface water in urban areas, and it is possible to note that many of the parameters showed much higher concentrations than the limits recommended by CONAMA Resolution 357/05, for rivers Class II. It was also found that the BOD5, the COD, turbidity, and total solids best parameters were the first flush indicators. With the results obtained load was observed that the rainfall events are large contributors to the concentration of pollutants in water bodies, since high loads are transported solids and COD. Thus, the results show that the runoff can carry high concentrations of pollutants into the stream Botafogo and this may suffer siltation and eutrophication. Thus, it is demonstrated the urgent need to study the diffuse loads in water bodies, especially in urban areas and assess the measures that can be undertaken in the basin as a preventive, adoption of alternatives for the control and treatment of pollution and mitigation of impacts caused by human actions. / A urbanização de forma acelerada e desorganizada tem causado diversos impactos ao meio ambiente modificando, tanto as condições de vida das populações, quanto a qualidade dos recursos hídricos. O presente trabalho teve como objetivo caracterizar a qualidade e a quantidade das águas e as cargas poluidoras do Córrego Botafogo, situado em Goiânia-GO, nos períodos seco e chuvoso por meio de análises de qualidade e quantidade, a fim de conhecer o comportamento da qualidade da água do corpo hídrico e apresentar os impactos do escoamento superficial no corpo hídrico. No período de seca foram realizados nove monitoramentos em oito pontos amostrais e no período de chuva um ponto apenas foi avaliado em 5 eventos chuvosos. As análises discriminatórias (boxplot), de cluster e de correlação foram essenciais para compreender as variações da qualidade da água em períodos secos, demonstrando que em monitoramentos futuros há a possibilidade da diminuição do número de pontos e parâmetros amostrais. Foi possível observar, ainda, que os parâmetros DQO, DBO5, cor, turbidez, coliformes totais e E.coli apresentaram clara variação sazonal. Nos cinco eventos de chuva avaliados foi possível perceber grandes oscilações na concentração dos parâmetros durante os monitorados, em especial coliformes Totais e E.coli, sólidos suspensos totais e turbidez, demonstrando claramente o impacto da drenagem pluvial nas águas superficiais em áreas urbanas, sendo que é possível notar que muitos dos parâmetros avaliados apresentaram concentrações muito superiores aos limites preconizados na Resolução CONAMA 357/05, para rios de Classe II. Verificou-se, ainda, que a DBO5, a DQO, a turbidez e os sólidos totais foram os melhores parâmetros indicadores de first flush. Com os resultados de carga obtidos foi possível perceber que os eventos chuvosos são grandes contribuidores para a concentração de poluentes nos corpos hídricos, uma vez que são transportadas elevadas cargas de sólidos e DQO. Dessa forma, os resultados encontrados apresentam que o escoamento superficial pode transportar elevadas concentrações de poluentes para o Córrego Botafogo e este pode vir a sofrer assoreamento e eutrofização. Assim, demonstra-se a extrema necessidade de estudar as cargas difusas nos corpos hídricos, especialmente em áreas urbanas e avaliar as medidas que possam ser realizadas na bacia como ações preventivas, adoção de alternativas para o controle e tratamento dessa poluição, bem como mitigação dos impactos causados por ações antrópicas.
6

Croissance et caractérisation des boîtes quantiques InAs/GaAs pour des applications photovoltaïques

Zribi, Jihene January 2014 (has links)
Ce travail de thèse porte sur l’étude de l’effet des boîtes quantiques d’InAs sur l’efficacité de conversion des cellules solaires à simple jonction de GaAs crues par épitaxie par jets chimiques. Cette technique de croissance est particulièrement bien adaptée à la croissance de structures multicouches pour des applications photovoltaïques. Une partie importante de ce travail a été consacré à l’optimisation des conditions de croissance pour la réalisation des boîtes quantiques d’InAs et de structures à multicouches de boîtes quantiques d’InAs insérées dans une matrice de GaAs. L’optimisation des conditions de croissance des boîtes quantiques a été basée sur une étude morphologique réalisée à l’aide de mesures de microscopie à force atomique et sur une étude des propriétés optiques et électroniques effectuée à l’aide de mesures de photoluminescence en continu. Une optimisation de la quantité d’InAs déposée lors de la croissance des BQs d’InAs/GaAs a permis de montrer que les meilleures structures de BQs ont été obtenues pour une épaisseur nominale d’InAs comprise entre 2.07 et 2.47 monocouches atomiques avec une haute densité (8 × 10[indice supérieur 10] cm[indice supérieur −2]) et une énergie d’émission de 1.22 eV (λ= 1016 nm). La croissance des multicouches de boîtes quantiques, dans des conditions usuelles de maintien de la température lors de l’épitaxie des couches de barrière de GaAs, a montré des difficultés dues à l’accumulation de la contrainte dans la structure. Deux types d’amas d’InAs ont été observés : soit des boîtes quantiques cohérentes de petite taille (diamètre et hauteur typiques de 5 nm et 16 nm, respectivement) et des amas relaxés de grande taille (diamètre et hauteur de plus de 50 nm et 150 nm, respectivement). Dans ces conditions de croissance nos résultats ont montré que la formation des amas de grande taille est accompagnée par une diminution de la densité des boîtes quantiques au fur et à mesure que le nombre de couches de boîtes quantiques augmente. L’application d’une étape appelée "indium-flush" (procédéd’évaporation d’indium sous atmosphère d’arsenic) pendant la croissance des couches de barrière de GaAs, qui encapsulent les boîtes quantiques, a montré une amélioration de la qualité cristalline de la structure globale. Les caractérisations morphologique et optique d’une série d’échantillons contenant 1, 5 et 10 plans de boîtes quantiques ont montré une préservation de la densité de boîtes quantiques et de leur distribution en taille. Les résultats montrent également que l’intensité intégrée de la photoluminescence des boîtes quantiques augmente linéairement en fonction du nombre de plans de boîtes quantiques. La structure finale optimisée est donc très prometteuse pour la réalisation de cellules solaires à boîtes quantiques à haute performance. L’étude de l’effet des boîtes quantiques et l’influence de leur hauteur sur l’efficacité des cellules solaires simple jonction de GaAs ont été analysés. Des mesures de l’efficacité quantique externe et des mesures I-V ont été effectuées pour caractériser ces cellules solaires. La technique de l’indium-flush a été utilisée pour contrôler la hauteur des boîtes quantiques. Une meilleure performance a été obtenue par la cellule solaire à boîtes quantiques tronquées à 2.5 nm de hauteur avec 5% d’amélioration de l’efficacité de conversion.
7

THE NEURONAL CIRCUITRY OF ESTROGENIC EFFECTS ON THERMOREGULATION

Dacks, Penny Ann Frances January 2010 (has links)
Approximately 75% of menopausal women in the United States experience hot flushes but the etiology of this thermoregulatory disorder is unknown. The dominant theory is that estrogen withdrawal sensitizes thermoregulatory areas of the brain, leading to the inappropriate activation of heat loss effectors in response to mild stimuli. This dissertation examines the circuitry of estrogen effects on thermoregulation. First, a rodent model was characterized. In ovariectomized rats, estradiol treatment decreased tail skin vasodilatation, a primary heat loss mechanism, and raised the ambient temperature threshold for tail skin vasodilatation. These results indicate that estradiol does not alter the maximal ability of blood vessels to constrict and dilate, but rather shifts the threshold for thermoregulatory activation in rats. Using this animal model, we examined how estradiol treatment and ambient temperature affect neuronal activity in brain areas involved with thermoregulation and reproduction. Out of 14 examined regions, only 3 areas were significantly affected by both estradiol and temperature and only the median preoptic nucleus (MnPO) exhibited increased activity at warmer ambient temperature. Interestingly, the effects of estradiol and ambient temperature on MnPO activity closely resembled their effects on tail skin vasodilatation. These results identify the MnPO as a plausible site for the integration of estrogen with skin vasodilatation. In the third study, we examined whether thermoregulation can be modified by neurokinin 3 (NK3) receptors, the dominant receptor for neurokinin B (NKB). Core temperature in ovariectomized rats was decreased by microinfusion of a selective NK3 receptor agonist into the MnPO and adjacent septal areas. This transient hypothermia was accompanied by a lack of homeostatic tail skin vasoconstriction but was not caused by tail skin vasodilatation or a global impairment in thermoregulation. These results demonstrate that thermoregulation in rats is modified by NK3 receptors in brain areas that receive projections from NKB neurons. In humans, menopause is associated with hot flushes and the hypertrophy and increased NKB gene expression in arcuate (infundibular) neurons. We propose a novel theory that estrogen withdrawal causes hot flushes by enhancing NKB release from arcuate (infundibular) neurons onto NK3 receptors.
8

Flush foliar na estação seca em floresta de terra firme na Amazônia central via webcam

Marostica, Suelen Jorge Felizatto 19 July 2011 (has links)
Submitted by Dominick Jesus (dominickdejesus@hotmail.com) on 2016-02-11T15:04:28Z No. of bitstreams: 2 Dissertação_Suelen Jorge Felizatto Marostica.pdf: 1026296 bytes, checksum: 36ee71cfff46dbaa799cf8fce9696935 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-11T15:04:28Z (GMT). No. of bitstreams: 2 Dissertação_Suelen Jorge Felizatto Marostica.pdf: 1026296 bytes, checksum: 36ee71cfff46dbaa799cf8fce9696935 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-07-19 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / There is an ongoing debate about the response of Amazon forests to extreme and to normal seasonal drought. Satellite observed Amazon green-up during the 2005 drought remains controversial, with green-up attributed by some to cloud/aerosol contamination. Satellite detection of dry-season green-up in years of normal rainfall is also confounded in the southern Amazon by decreasing solar zenith angle. To address these concerns by direct assessment of changes in the forest canopy, a high-resolution (1028x720p) 3-band video camera was mounted 54 m above the forest floor on an eddy covariance tower 60 km north of Manaus. Camera aim was south, perpendicular to the solar transit, with an oblique downward view. Automatic color balance was turned off. For 134 days from the middle of the dry season to mid rainy season (23 Sept, 2010 to 03 Feb, 2011) one frame was captured every 10s. From these, a single frame was chosen per day, obtained under diffuse solar illumination near local noon with minimal variation (< +-10%) in overall reflected scene brightness. Auto-exposure of the camera compensated this minor variation. Changes in greenness and woodiness were examined using three approaches: (1) visual classification of transition types for all trees that underwent marked full-crown changes during the dry season; (2) relative green channel brightness averaged over the entire frame; and (3) unstandardized Principal Component Analysis of the entire frame to remove spatial variations in illumination (PC1) and estimate area of exposed bark (threshold of PC2). Of 13 trees that underwent full-crown transitions in the first month (dry season), 11 were experiencing some stage of leaf flush . Relative brightness of the green channel over the entire frame showed that a flush of new leaves was already taking place at the beginning of the study and continued at least into October, when leaf maturation caused changes in leaf colors, limiting the usefulness of this indicator. The area of exposed bark decreased steeply during the mid-dry season leaf flush and further suggested that leafing-out continued at a slower pace into the rainy season. Due to spectral stability of exposed bark over time, this is a more reliable indicator of leaf phenology than the leaves themselves. The results of this study contribute an understanding of what controls seasonality of vegetation greenness in Amazonia and its photosynthesis response. / Existe um debate em curso sobre a resposta das florestas na Amazônia às secas extremas e às variações sazonais normais. Observações a partir de um sensor orbital de green-up na Amazônia durante a seca de 2005 permanecem controversas, com grande parte do fenômeno atribuído a contaminações por nuvens/aerossóis. Detecção por satélite do green-up no sul da Amazônia na estação seca foi atribuída ao artefato de sazonalidade no ângulo solar. Para avaliar mais diretamente as mudanças no dossel de uma floresta de terra firme da Amazônia Central, utilizou-se uma câmera de vídeo com três bandas na faixa do visível, resolução de 1028x720 pixels, fixa 54 m acima do chão da floresta em uma torre de covariância de fluxo, 60 km ao norte de Manaus. A mira da câmera foi ao sul, perpendicular ao trânsito solar, e obliqua para baixo. Foi desligada a compensação automática de cor (color-balance). Ao longo de 134 dias entre o pico da estação seca e o meio da estação chuvosa (23-set, 2010 a 03-fev, 2011), foi capturado um frame a cada 10 s. Foi selecionado ~um frame por dia, sob iluminação solar difusa, próximo ao meio-dia local e com variação < +/-10% no brilho geral refletido. A exposição automática da câmera compensou esta variação. As mudanças em greenness e madeirosidade foram medidas usando três abordagens: (1) classificação visual de tipos de transição para todas as árvores que experimentaram mudanças na copa por inteiro, durante o pico da estação seca; (2) médio, em todo o frame, do brilho relativo do canal verde; e (3) análise de componentes principais, com dados não padronizados, sobre todo o frame, para remover variações espaciais na iluminação (PC1) e estimar a área de madeira exposta (limiar do PC2). Das treze árvores que sofreram uma transição completa da copa na estação seca, onze experimentaram algum estágio de flush foliar. O brilho relativo do canal verde mostrou que este flush de folhas novas já estava acontecendo no início do estudo e continuou pelo menos até outubro, quando a maturação das folhas causou mudanças na sua coloração, limitando o uso desse indicador. A área de madeira exposta diminuiu abruptamente durante a estação seca e continuou caindo em ritmo menor no decorrer da estação chuvosa. Este indicador foi considerado mais confiável, devido a sua estabilidade espectral. Os resultados deste estudo contribuem para o entendimento da real sazonalidade de greenness da vegetação na Amazônia e sua resposta à fotossíntese.
9

Evaluation of Contaminant Mixing in Rainwater Harvesting First Flush Diverters

Mechell, Justin K. 14 January 2010 (has links)
As the world population increases, the demand increases for quality drinking water. The harvesting of rainwater has the potential to assist in alleviating pressures on current water supplies and storm water drainage systems. Diversion of a portion of the collected water away from storage is a technique used to improve harvested rainwater water quality prior to storage. Six configurations of a downspout first flush diverter were constructed and tested in the laboratory. The configurations of diverters were evaluated for their affinity to allow diverted water in the diverter chamber to interact with the flow of water to storage. Experiments were conducted at flow rates ranging from 0.76 L/min to 113.56 L/min. This range of flow rates adequately represents a wide range of common storm intensity patterns across the United States to which downspout first flush diverters are subjected. The diverter chamber to downspout transition fittings tested on a 10.16 cm diameter diverter chamber, upward and downward oriented sanitary and straight tee, do not have a significant impact on the mean difference in initial and final total dissolved solids concentrations observed at multiple sample ports. No statistical difference was observed when comparing upward and downward oriented sanitary tees used as diverter chambers to downspout transition fittings on 10.16 and 15.24 cm diverter chambers. Utilizing a straight tee as a transition fitting with a floating ball, acting as a barrier between water collected in the diverter chamber of a downspout first flush diverter and the flow passing through the transition fitting, limited diverted water from interacting with the subsequent flow of harvested rainwater. There is not a significant difference between the use of a downspout first flush diverter with diverter chamber diameters of 10.16 and 15.24 cm utilizing upward and downward oriented sanitary tees as downspout to diverter chamber transition fittings. Tests at flow rates less than or equal to 12.11 L/min exhibited limited changes in total dissolved solids concentrations in the downspout first flush diverters with 15.24 cm diameter diverter chambers. Tests at flow rates less than or equal to 1.51 L/min exhibited limited changes in total dissolved solids concentrations in the downspout first flush diverters with 10.16 cm diameter diverter chambers. The diverter chamber drain flow rate and volume impacts the observed differences in initial and final TDS concentrations at all sample ports on the diverter chamber of a downspout first flush diverter regardless of flow rate. The diverter chamber drain flow rate impacts the flow rate of water entering the diverter chamber through the transition fitting.
10

High volume flush vs. low-flush water closets and solid waste transport distance: a comparative study

Reyes, Matthew David 17 February 2005 (has links)
Upon the enactment by the United States Congress of the 1992 Energy Policy Act, it became mandatory that all water closets in residential and commercial settings reduce the volume of water that they consume per flush. In 1994, after installations began of the new low-flush or low-flow water closets that used less than half the water that their predecessors used, many owners of the new plumbing fixtures began to complain that their performance was sub par. Many complained about plumbing backups and of complete bowl clearance problems. There have been studies conducted to evaluate the new water closets’ bowl evacuation properties. This study focuses on what happens to the solid waste that is flushed through the water closet after leaving the bowl, namely how far the solid media is transported down waste piping. The main focus of this study is to compare the performance of the low-flush, 1.6 gallons (6 liters) per flush water closets with the performance of the formerly standard flush 3.5 gallons (13 liters) per flush in regards to how far they transport solid waste through waste lines. It was found that the media flushed through the high volume water closets traveled significantly farther that the media flushed through the low-flush water closets. It was often more than double the average distance. It was also found that media traveled farther down pipes composed of PVC than those composed of cast iron and also traveled farther down three inch pipes than four inch pipes.

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