Swimming pool thermal energy storage, an alternative for distributed cooling energy storage

© 2020 The Author(s) The rise in distributed renewable energy generation creates a growing need to find viable solutions for energy storage to match energy demand and supply at any time. This paper evaluates the possibility of using swimming pools as a long-term cooling energy storage solution, i.e., Swimming Pool Thermal Energy Storage (SPTES). This technology allows a small building to store solar energy for cooling purposes in a yearly cycle, by filling the pool with ice slurry in winter and using that ice to cool the house in the summertime. Additionally, the pool can be used as a heat sink for a heat pump to heat the house during the winter. Results show that the energy storage cost of 0.078 US$kWhe−1 is substantially smaller when compared with batteries (125 US$ kWhe−1). This makes SPTES a good alternative to support the development of 100% renewable energy systems in locations where the climate has a highly seasonal variation in temperature and the cooling demand is high in summer

The Threshold Bias Model: A Mathematical Model for the Nomothetic Approach of Suicide

Comparative and predictive analyses of suicide data from different countries are difficult to perform due to varying approaches and the lack of comparative parameters.A simple model (the Threshold Bias Model) was tested for comparative and predictive analyses of suicide rates by age. The model comprises of a six parameter distribution that was applied to the USA suicide rates by age for the years 2001 and 2002. Posteriorly, linear extrapolations are performed of the parameter values previously obtained for these years in order to estimate the values corresponding to the year 2003. The calculated distributions agreed reasonably well with the aggregate data. The model was also used to determine the age above which suicide rates become statistically observable in USA, Brazil and Sri Lanka.The Threshold Bias Model has considerable potential applications in demographic studies of suicide. Moreover, since the model can be used to predict the evolution of suicide rates based on information extracted from past data, it will be of great interest to suicidologists and other researchers in the field of mental health

Studies on the optimal behavior of energy storage in reservoirs of a hydroelectric system

This work aims at studying the results of an optimization mode/applied to the Paranaiba river basin, Brazil This system is made by the junction of three river branches located In a region with a well-defined seasonal hydrological behavior The ratio between the total energy storage in the system and the active storage for every reservoir is evaluated from the optimal operational results. This relationship allows recognizing systematic patterns on the relative use for every reservoir, when compared to the entire system. The main parameters that define reservoir behavior are identified, with highlights on the position of the power station In the cascade, the relationship between the river flow and the active storage, and the installed capacity of the power station In addition, the parameter "hydrological scenario" is also another factor that defines the relative use of the reservoirs.173172

Multiobjective real-time reservoir operation with a network flow algorithm

A network flow algorithm has been developed for the optimization of real-time operation of a multiple reservoir system. Two purposes have been considered in the operation: flood control and hydropower generation. A special network structure was developed which allows the consideration of river routing. A multiobjective formulation is utilized thus allowing generation of a non-dominated curve. The effect of imperfect forecast on the performance of the real-time operation model is also evaluated. An application is made to a subsystem of the Brazilian hydroelectric system, located in the Paranapanema river basin. In this case study, the model showed good performance under the largest flood of the historical records.37483785

Interbasin Water Transfers: The Brazilian Experience and International Case Comparisons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This paper critically examines Brazil's transbasin diversion experiences and two select, large-scale transbasin projects outside of Brazil. Rather than simply compare Brazil's experiences with international cases, the authors explore the historical context of the projects, focusing on the water resources and environmental regulatory and institutional frameworks in place during the initial proposals and how they influenced the projects' development and completion rates. Huge investments, the lengthy time span between the date of the initial project proposals and the start of construction, the need to garner public and political support, and more recently, the need to fulfill national and regional environmental laws are major factors underlying heated public debates about the proposed projects. After a broad discussion about the subject, the authors examine a recently approved large-scale Brazilian project, the Sao Francisco river transbasin diversion. This river diversion project is considered crucial to the economic development of Brazil's semi-arid northeastern region. Despite the fact that this government-funded project was debated for several decades among the various stakeholders, it was approved under Brazil's newly formed water resources regulatory and environmental framework, which enabled improvements in various key technical aspects of the project, and greater involvement of various key social players.25819151934Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2008/58508-1

Purification and biological effects of a C-type lectin isolated from Bothrops moojeni

Snake venom proteins from the C-type lectin family have very distinct biological activities despite their highly conserved primary structure, which is homologous to the carbohydrate recognition region of true C-type lectins. We purified a lectin-like protein (BmLec) from Bothrops moojeni venom and investigated its effect on platelet aggregation, insulin secretion, antibacterial activity, and isolated kidney cells. The BmLec was purified using two chromatographic steps: affinity chromatography and reverse phase high performance liquid chromatography (HPLC). BmLec showed a dose-dependent platelet aggregation and significantly decreased the bacterial growth rate in approximately 15%. During scanning electron microscopy, the profile of Xanthomonas axonopodis pv. passiflorae treated with lectin disclosed a high vesiculation and membrane rupture. BmLec induced a strong and significant increase in insulin secretion at 2.8 and 16.7 mM glucose concentrations, and this effect was seen in the presence of EGTA in both experiments. BmLec (10 µg/mL) increased the perfusion pressure, renal vascular resistance and urinary flow. The glomerular filtration rate and percentages of sodium, potassium and chloride tubular transport were reduced at 60 minutes of perfusion. Renal alterations caused by BmLec were completely inhibited by indomethacin in all evaluated parameters. In conclusion, the C-type lectin isolated from Bothrops moojeni affected platelet aggregation, insulin secretion, antibacterial activity and isolated kidney function

Effects of Crotalus durissus collilineatus venom in the isolated rat kidney

Ophidian accidents caused by the subspecies Crotalus durissus are responsible for high morbity and mortality rates. Acute renal failure is a common complication observed in these accidents. The aim of the present study was to investigate the renal effects promoted by the venom of C. d. collilineatus and its fractions, crotoxin and phospholipase A, C. d. collilineatus (Cdc; 30 mu g mL(-1)), crotoxin (CTX; 10 mu g mL(-1)) and phospholipase A(2) (PLA(2); 10 mu g mL(-1)) were tested in isolated rat kidney. The first 30 min of each experiment were used as an internal control and Cdc or its fractions, CTX and PLA(2) were added to the system after this period. All experiments lasted 120 min. The venom of Cdc decreased perfusion pressure (PP; control(120) = 110.3 +/- 3.69 mmHg; Cdc(120) = 96.7 +/- 8.1 mmHg), renal vascular resistance (RVR; control(120) = 6.42 +/- 0.78 mmHg mL g(-1) min(-1); Cdc(120) = 4.8 +/- 0.56 mmHg/mL g(-1) min(-1)), urinary flow (UF; control(120) = 0.19 +/- 0.03 mL g(-1) min(-1); Cdc(120) = 0.12 +/- 0.01 mL g(-1) min(-1)), and glomerular filtration rate (GFR; control(120) = 0.79 +/- 0.07 mL g(-1) min(-1); Cdc(120) = 0.53 +/- 0.09 mL g(-1) min(-1)), but had no effect on the percent of sodium tubular transport (%TNa+), percent of chloride tubular transport (%TK+) and percent of potassium tubular transport (%TCl-). CTX and PLA(2) reduced the GFR, while UF, PP and RVR remained stable during the full 120 min of perfusion. Crotoxin administration also diminished the %TK+ (control(120) = 69.94 +/- 6.49; CTX120 = 33.28 +/- 4.78) and %TCl- (control(120) = 79.53 +/- 2.67; CTX120 = 64.62 +/- 6.93). PLA(2) reduced the %TK+, but exerted no effect on the %TNa+ or on that of TCl-. In conclusion, the C. d. collilineatus venom altered the renal functional parameters evaluated. We suggest that crotoxin and phospholipase A(2) were involved in this process, since the renal effects observed would be due to the synergistic action of the components of the venom. (c) 2005 Elsevier Ltd. All rights reserved.47326026

Renal toxicity of Bothrops moojeni snake venom and its main myotoxins

Acute renal failure is one the most common systemic complications after snakebite, however, its pathogenesis remains obscure. In this study we evaluated the renal effects of Bothrops moojeni venom and its myotoxins (Bmtx-I and BmtxII) in rat isolated perfused kidneys. The myotoxins were purified by ion-exchange chromatography and reverse phase HPLC. The whole venom (10 mug/ml) and myotoxins (5 mug/ml) were added to the perfusion system 30 min after the beginning of each perfusion. The renal effects were compared to a control group perfused with modified Krebs-Henseleit solution alone. B. moojeni venom decreased the perfusion pressure (PP), renal vascular resistance (RVR), and the percent sodium, potassium and chloride tubular transport (%TNa+, %TK+, %TCl-). In contrast, the venom increased the urinary flow (UF), glomerular filtration rate (GFR), and the sodium, potassium and chloride excretion (ENa+, EK+, ECl-). The renal effects of myotoxin I was very similar to those of the whole venom, but there was an increase rather than a decrease in the PP and RVR. Myotoxin II had no effect on renal physiology, except for a transient decrease in %TK+. In conclusion, B. moojeni venom caused intense alterations in renal physiology, including a drop in vascular resistance associated with diuresis, natriuresis and kaliuresis. Bmtx-I had an opposite effect when compared to whole venom, showed in the parameters of PP and RVR. Bmtx-II had a mild effect in %TK+. The apparent inability of Bmtx-II to induce the renal effect similarly to Bmtx-I should be explained by the absence in the Bmtx-II of the C-terminal lysine rich region. (C) 2002 Elsevier Science Ltd. All rights reserved.40101427143

Purification and biological effects of C-type lectin isolated from Bothrops insularis venom

Bothrops insularis is a snake from Queimada Grande Island, which is an island located about 20 miles away from the southeastern coast of Brazil. Compared to other Brazilian species of Bothrops, the toxinology of B. insularis is still poorly understood. Its C-type lectin is involved in several biological processes including anticoagulant and platelet-modulating activities. We purified the C-type lectin (BiLec) from Bothrops insularis venom and investigated its effect in the isolated kidney. BiLec was purified after two chromatographic steps; firstly, the whole venom was submitted to an HPLC molecular exclusion chromatography followed by a second purification through affinity chromatography. B. insularis lectin (BiLec) was studied as to its effect on the renal function of isolated perfused rat kidneys with the use of six Wistar rats. The concentration of 10 mu g/mL increased perfusion pressure (PP; control(60) = 108.27 +/- 4.9; BiLec(60) = 112.9 +/- 5.4 mmHg; *p < 0.05) and renal vascular resistance (RVR; control(60)=5.38 +/- 0.51; BiLec(60)=6.01 +/- 0.57 mmHg; *p < 0.05). The urinary flow reduced significantly at 90 and 120min of perfusion (UF; control(120)= 0.160 +/- 0.020; BiLec(120) =0.082 +/- 0.008mL g(-1) min(-1); *p < 0.05). Glomerular filtration rate (GFR; control(120)=0.697 +/- 0.084; BiLec(120)=0.394 +/- 0.063 mL g(-1) min(-1); *p < 0.05) diminished only at 120 min. BiLec did not change the percentage of sodium (TNa+), potassium (TK+) and chloride tubular transport (TCl-). The histological alterations probably reflected direct injury on glomerular and tubular renal cells, as demonstrated by the rise in permeability of glomerular endothelial cells, revealed by the presence of a proteinaccous material in the Bowman space. We postulate that the C-type lectin B. insularis promoted its effects probably through interactions with endothelial cells or through the release of other mediators by tubular, mesangial and endothelial cells. (c) 2006 Elsevier Ltd. All rights reserved.47885986