Blowflies (Diptera: Calliphoridae) are main colonizers of decomposing remains and any information on the influences of their lifecycle of growth and development are important to forensic entomologists when estimating postmortem interval during a medicolegal death investigation. Pupal survival of blowfly species, Lucilia sericata were studied at different developmental stages following pupation, white (0-12 hrs), young (24 hrs), medium (5 days), old (9 days) were submerged at various immersion intervals ranging from 1 hr to 120 hr (5 days) in different water types (fresh, salt, polluted, and drinking water). Control group (N= 100) were white pupae that were not submerged were also observed in order to compare the survival and eclosion rate. Two trials of the submergence process were conducted to observe the pupae survival. Data were analyzed using multiple logistic regressions in a 3-way interaction to determine if significant differences were seen between the water, time in water, and pupal stage. Dissolved inorganic nitrogen (DIN) of NH4+, NO2-, NO3-, and oP or DIP were analyzed to examine to determine if a correlation between the water types could be seen. DIN analyses exhibited similar NO2- + NO3- and NO3- in polluted and fresh water. The results show that as the pupae developmental age progressed, the pupae generally survived longer immersion intervals. The survival of white pupae decreased with the increase of submergence for all four water types, exhibiting a 100%mortality rate with pupae submerged longer than 24-36 hours. While pupae immersed in polluted water had similar survival rates in the white stage, the survival rate declined as the developmental age increased for pupae immersed in polluted water. Pupae immersed in salt and polluted water had earlier eclosion times when compared to other water groups, emerging at 36 hours from when the control group first emerged at day 12. Understanding the survival rate of submerged Lucilia sericata (Diperta: Calliphoridae) pupae will be potentially useful for criminal investigations by providing a better understanding of the survival of pupae submerged in different aquatic environments.

Human remains enter marine environments in a number of ways ranging from homicides, suicides, accidental drownings, shipwrecks, to burials at sea. Once the remains are discovered, a legal and forensic investigation begins. A key component to this investigation is the postmortem submergence interval (PMSI). Determining this range on skeletonized remains is a complicated process in which there is no accurate test; although barnacle growth data was previously used to determine PMSI, there are still limitations with that method. Therefore, a more reliable component of bone needs to be used as a potential PMSI indicator, such as its elemental composition. Diagenesis starts affecting bones immediately and continues for thousands of years. Although diagenesis is a slow process, an exchange of elements between bone and the marine environment continually occurs. The purpose of the present study is to determine whether an increase in marine elements is found within the composition of bone after being submerged in a marine environment for up to 20 months. The present study will also determine whether bones submerged in different aquatic environments have significantly different elemental concentrations. For the time trials, pig femora were submerged in lobster cages off the coast of the University of Massachusetts Boston for 2-20 months. For the salinity trials, pig femora were submerged in a freshwater pond (Holliston, MA), the Inner Boston Harbor, and an ocean inlet near Woods Hole, MA for 18 months. All bone samples were dried, milled, homogenized, and analyzed by ED-XRF under He purge. The initially produced mass percentages of the identified elements were corrected with certified values of standard reference materials (NIST 1486, 1646a, and 2702). A Pearson’s correlation test determined that the concentrations for K, Fe, Zn, Sr, Si, S, Cr, Mn, Cl, Br, Ta, and W were significantly correlated to the amount of time submerged in the water. An ANCOVA analysis was applied to the significant elements noted above. After adjusting for the amount of time submerged, the concentrations of K, Fe, Sr, Si, S, Cl, Br, and Ta were determined to be significantly different between the control samples (never submerged) and the submerged samples (submerged for 2-20 months). K was the only element that had greater concentrations in the control samples than the submerged samples, most likely because of the decrease in mass percent as other environmental elements were incorporated into the bone. S and W were significantly related to the number of months submerged, with S being positively influenced and W being negatively. A multivariable linear regression was run in order to identify a means of predicting the amount of time submerged from the elemental concentrations of an unknown bone from a marine environment. The regression produced an equation that used the concentrations for K, Sr, Si, S, Cr, Cl, and Br to predict the PMSI in months. For the salinity trials, a one-way ANOVA was performed on all the elemental concentrations from the different salinity environments. Post hoc tests determined significant differences in elemental concentrations for K, Fe, Si, S, Al, Ti, Cr, Ni, Mn, Cl and Br among the different submergence locations; elemental concentrations of S, Fe, Mn, Cl, K, and Br were either significantly different between the fresh, brackish, and saltwaters or the freshwater and some form of marine water (brackish and salt). The trends in the other elemental concentrations were less obvious due to the impact of pollution within the surrounding environments. The linear regression equation created in the present study accounted for the majority of the variance in the outcome (R2 = 80.2%); however, this equation should not currently be applied in forensic investigations. The study needs to be repeated a number of times with other bone samples from the same and different submergence locations, in order to determine the accuracy and usefulness of the equation. Although not verified, this regression equation may be useful in analyzing samples from brackish and saltwater environments, because the majority of the variables within the equation (K, Sr, S, Cl, Br) were consistent among the fresh, brackish, and saltwater samples. Time constraints, small sample sizes, and variance among samples were the major limitations of the present study. Even with limitations, significant results were produced by the ED-XRF analysis. Future research should expand upon the methodologies of XRF analyses of bones, especially those from marine environments. Because of their relevance to forensic investigations and PMSI, future research should include longer experimental periods, more salinity locations, more information on the surrounding water components, and more comparisons among instrumentation.

This study examined the acid-base and ionoregulatory responses by the skin and kidney of adult bullfrogs (Rana catesbiana) during recovery from non-respiratory acidoses. Acidosis was induced by intravascular infusions of HCl (3,000 uequiv/kg), or NH4Cl (4,000 uequiv/kg), or by 45 min enforced submergence. Infused acids were immediately buffered by the extracellular fluids (ECF) and moved rapidly into the intracellular compartment. Clearance of the acid load was slow (> 24 h post-infusion) and only in NH4Cl loaded frogs was the full amount cleared within 5 days. Excess acid was excreted primarily by increased renal NH4+ effluxes. The skin contributed very little to the net acid excretion; instead large "base" losses ("acid" uptake) occurred. Acid infusions also resulted in large ion losses and elevated water uptake across the skin, with electrolytes and water moving down chemical gradients. Frogs infused with HCl died within 96 h; NH4Cl loaded frogs all survived.Forced submergence resulted in a severe lactacidosis which was corrected in 12 h by a combination of renal/cutaneous acid excretion (9:1 ratio) and metabolic utilization of lactate and H+ (~ 95% of excess acid load). Acid excretion occurred primarily as NH4+ efflux by the kidney and skin. A 1:1 exchange of Na+ influx/NH4+, efflux across the skin was found (r = 0.94; P < 0.01) when Jin Na+ was elevated over basal levels (30-40 uequiv/kg·h). Lactate and net acid effluxes by the skin and kidney diminished by 24 h post-disturbance and accounted for 4 to 6% of the total estimated load to the animal. All frogs survived the diving protocol. Restoration of acid-base state in acidotic bullfrogs by ECF and non-ECF mechanisms, as well as the renal and cutaneous responses to the acidosis, is discussed and compared to that of other vertebrates. It is concluded that anurans, and the bullfrog in particular, are poor regulators of acid-base state but instead are very tolerant to marked disturbances of acid-base balance. / Thesis / Master of Science (MS)

This diploma thesis deals with submergence of low rectangular sharp-edged broad-crested weirs. From measurement of water levels in front of and behind of weir at different discharges and different weir heights, were determined values of submergence coefficient depending on relative height of submergence. From these values were determined the equation of submergence coefficient. Measured values were compared which results measurements, which are given in professional literature.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-03-23T17:32:41Z No. of bitstreams: 1 Sérgio Leonardo Neves.pdf: 2909567 bytes, checksum: a962e9493a93ecd2b5b1d0c54d5b4fef (MD5) / Made available in DSpace on 2015-03-23T17:32:41Z (GMT). No. of bitstreams: 1 Sérgio Leonardo Neves.pdf: 2909567 bytes, checksum: a962e9493a93ecd2b5b1d0c54d5b4fef (MD5) Previous issue date: 2014-06-05 / FAURGS - Fundação de Apoio da Universidade Federal do Rio Grande do Sul / A contribuição da energia hidráulica na matriz energética nacional, segundo o Balanço Energético Nacional de 2011, é de aproximadamente 88,8%. Apesar da tendência de aumento de outras fontes energéticas, tais como: térmica, eólica, solar, tudo indica que a energia hidráulica continuará sendo, por muitos anos, a principal fonte geradora de energia elétrica do Brasil. Antes de se tornar energia elétrica, a energia hidráulica deve ser transformada em energia cinética que através de uma turbina é convertida em energia mecânica. Como último elemento do sistema, um gerador acoplado a turbina gera energia elétrica onde é distribuída aos consumidores. A eficiência de uma usina hidrelétrica pode ser afetada pelas condições de alimentação de água para sua tomada d'água. Esta operação deve ser estável, evitando distúrbios que possam interferir no desempenho do sistema. A formação de vórtices a montante das tomadas de água são causas de perda de eficiência e podem causar danos nas instalações, provocando paradas não programadas. Por isto, a formação de vórtices deve ser conhecida e evitada. O objetivo deste trabalho é estudar o fenômeno de formação de vórtices em tomadas de água de hidrelétricas. Os resultados obtidos podem ser úteis para orientar projetos de novas instalações, ampliação de capacidade instalada de usinas em operação, e até mesmo para subsidiar as operações de usinas que possuem características que possam favorecer a formação de vórtices. Este trabalho faz parte do projeto ANEEL (PD-0394-0912/2011): "Formação de Vórtices em Tomadas De Água de Usinas Hidrelétricas", com patrocínio de Furnas Centrais Hidrelétricas S.A. e apoio do LAHE (Laboratório de Hidráulica Experimental de Furnas) e do IPH (Instituto de Pesquisas Hidráulicas da Universidade Federal do Rio Grande do Sul). O estudo é realizado com utilização de software comercial ANSYS-CFX, analisando diversos casos de submergência, vazão volumétrica e modelo de turbulência. O modelo matemático é composto pelas equações da conservação da massa e quantidade de movimento, assim como de suas respectivas condições de contorno. A validação dos resultados numéricos foi realizada comparando-se este com aqueles observados no modelo experimental do IPH-UFRGS em escala de tomada de água vertical desenvolvido pelo Instituto de Pesquisas Hidráulicas da UFRGS. / According to the 2011 National Energy Balance the contribution of hydro energy in the national energy matrix is approximately 88.8%. Despite the increasing trend of other energy sources, such as thermal, wind and solar power, everything indicates that hydropower will remain for many years the main source of electric power in Brazil. Before becoming electricity, hydropower must be transformed into kinetic energy that through a turbine is converted into mechanical energy. As a final element of the system, coupled to a generator turbine generates electricity which is distributed to consumers. The efficiency of a hydroelectric plant may be affected by conditions of water supply to it’s water intake. This operation should be stable, avoiding disturbances that can affect the system performance. The formation of vortices upstream of water intakes are causes of efficiency loss and can cause damage to the premises, causing unscheduled and unplanned downtime. Therefore, the formation of vortexes must be known and avoided. The objective of this work is to study the phenomenon of vortex and its formation at water intakes in a hydroelectric station. Obtaining results may be useful in guiding the design of new facilities, expansion of installed capacity of power plants in operation, and even to subsidizing the operations of plants that have characteristics that may favor the formation of vortices. This work is part of the research project: “Formation of vortices taken in water for hydroelectric plants”, with sponsorship and support from the Furnas Hydroelectric Hydraulics Laboratory of Experimental Furnas-LAHE and the Institute of Hydraulic Research -IPH/UFRGS. The studies is conducted using commercial software ANSYS CFX-analyzing several cases of submergence, water flow and turbulence model. The mathematical model composed by the mass and momentum equations as well as their respective boundary conditions is applied to a model of vertical water intake. The validation of the numerical results is obtained from literature data with existing studies on water intakes and vortex formation, as well as a verification of results found in the scale model of a vertical water intake developed by the Institute of Hydraulic Research UFRGS.

This study quantifies the influence of debris cages on critical submergence at vertical intakes in reservoir configurations. Four model debris cages were constructed of light panel material. A vertical intake protruding one pipe diameter above the floor of a model reservoir was tested in six configurations: open intake pipe, a debris grate placed directly over the intake pipe, and debris cages representing widths of 1.5*d and 2*d and heights of 1.5*c and 2*c, where d is diameter of the intake and c is height of intake above reservoir floor. A selection of top grating configurations and a submerged raft configuration were also tested for comparison. Testing of the model debris cages indicates that the roof or top grate of a debris cage dominates the influence a debris cage has on the reduction of critical submergence of air-core vortices. The side grates of a debris cage have some influence on the formation of vortices. The spacing of bars in the top grate has an influence on air-core vortex development. The presence of a debris cage at vertical intakes in still-water reservoirs reduces the critical submergence required to avoid air-core vortices and completely eliminates the air-core vortex for cases where the water surface elevation remains above the top grate of the debris cage. The potential exists for designing debris cages to fulfill a secondary function of air-core vortex suppression.

The aim of this experimental study was to investigate the hydraulic conditions at which air-entraining vortices would form in front of horizontal intakes and to determine the ways of eliminating the formation of these vortices by testing anti-vortex devices. For these reasons, a series of experiments were conducted in an experimental setup composed of a reservoir having the dimensions of 3.10 m x 3.10 m x 2.20 m and a pump connected to the intake pipe. Within the reservoir, between the concrete side walls adjustable plexiglass side walls were placed to provide the desired wall clearance for the intake pipes. Six pipes of different diameters / 5 cm, 10 cm, 14.4 cm, 19.4 cm, 25 cm and 30 cm were horizontally mounted on the front side of the reservoir one by one, and for each case, a wide range of discharges was provided from the reservoir by the pump. Under symmetrical approach flow conditions and zero bottom wall clearance, the experiments were repeated for each intake pipe and the &ldquo / critical submergence depths&rdquo / for the tested discharges were determined. At some of the discharges, the effect of horizontal plates located on the top of the pipe entrance as anti-vortex devices on the elimination of the vortices was investigated. The measured critical submergence depths were related in dimensionless form to the relevant dimensionless parameters and empirical equations were derived. These equations were compared with similar ones available in the literature and it was shown that the agreement between them was quite good.

Intakes are inlet structures where fluid is accelerated to a certain flow velocity to provide required amount of water into a hydraulic system. Intake size and geometry affects the formation of flow patterns, which can be influential for hydraulic performance of the whole system. An experimental study is conducted by measuring velocity field in the hydraulic model of the head pond of a hydropower plant to investigate vortex formation. Vortex strength based on potential flow theory is calculated from the measured velocity field. It was shown that vortex strength increases with the submergence Froude number. The free surface flow in the head pond is simulated using Flow-3D software. Vortex strength calculations are repeated using the computational velocity distributions and compared to experimentally obtained values. Similar computations were carried on with some idealized pond geometries such as rectangular and circular.

Yes / Researchers have recognized that the successive growth of mid-channel bar deposits can be entertained as the raison d’être for the initiation of the braiding process, which is closely interlinked with the growth, decay, and vertical distribution of fluvial turbulent kinetic energy (TKE). Thus, focused analysis on the underlying mechanics of turbulent flow structures in the proximity of a bar deposit occurring in the middle of the channel can afford crucial scientific clues for insight into the initiating fluvial processes that give rise to braiding. In the study reported herein, a physical model of a mid-channel bar is constructed in an experimental flume to analyze the turbulence parameters in a region close to the bar. Notably, the flow velocity plays an important role in understanding the flow behavior in the scour-hole location in the upstream flow divergence zone as well as near the downstream zone of flow convergence in a mid-channel bar. Therefore, the fluctuating components of turbulent flow velocity are herein discussed and analyzed for the regions located close to the bar. In the present study, the impact of the mid-channel bar, as well as its growth in turbulent flow, on higher-order velocity fluctuation moments are investigated. For near-bed locations, the results show the dominance of ejection events in upstream zones and the dominance of sweep events at locations downstream of the mid-channel bar. In scour-hole sections, the negative value of the stream-wise flux of turbulent kinetic energy and the positive value of the vertical flux of turbulent kinetic energy indicate energy transport in downward and forward directions, respectively. The downward and forward energy transport processes lead to scouring at these locations. The maximum turbulent production rate occurs in the wake region of the bar. The high rate of turbulence production has occurred in that region, which can be ascribed to the process of shedding turbulent vortices. The results show that the impact of the presence of the bar is mainly restricted to the lower layers of flow. The turbulent dissipation rate monotonically decreases with an increase in the vertical distance from the bed. The turbulent production rate first increases and then decreases with successive increases in the vertical distance from the bed. The paper concludes with suggestions for the future potential use of the present research for the practical purpose of examining braid bar occurrences in alluvial rivers to develop an appropriate response through training measures

In the present study, possible scale effects on the formation of air-entraining vortices at horizontal intakes are studied experimentally. Basic dimensionless parameters that govern the onset of vortices at a horizontal intake in a model and a prototype are stated by dimensional analysis. Series of experiments are conducted on four intake pipes of different diameters located in a large reservoir. The relationship of critical submergence ratio with other dimensionless parameters is considered for a given Froude number and it is found out that the critical submergence ratio is affected by model length scale ratio and its natural result of side-wall clearance ratio and Reynolds number differences between model and prototypes. It is observed that, side-wall clearance ratio is not effective on the critical submergence ratio after it exceeds about 6. In addition to this, Reynolds number limit, beyond which viscous forces do not affect the vortex flow, is found out to be increasing with the increase in Froude number. An empirical relationship, which gives the critical submergence ratio as a function of Froude number, side-wall clearance ratio and Reynolds number is obtained by using data collected in the experiments.