PDF superior Approximation to the study of water quality

Approximation to the study of water quality

Approximation to the study of water quality

A Topological Index is a numerical value that allows obtain information of a determined discrete structure associated with the invariants of a graph. The topological indices based on the degrees of vertices and edges have been used for more than 40 years. Among them, it is known that several are useful in the field of chemistry research. Probably, the best-known descriptor is the Randic connectivity index (R) [10]. There are several research works on this molecular descriptor (see, for example, [4], [8], [11], [12] and their references). For many years, scientists tried to enhance the predictive power of the Randic Index. This led to the introduction of a large number of topological descriptors correlated with the original Randic Index.
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10 Lee mas

Pollution of Water for domestic use and human consumption, by heavy metals Pb, Cd, Cr, Zn and As, Derived from mining Activity in Hidalgo del Parral, Chihuahua, México

Pollution of Water for domestic use and human consumption, by heavy metals Pb, Cd, Cr, Zn and As, Derived from mining Activity in Hidalgo del Parral, Chihuahua, México

Research was done with the objective of evaluating the quality of the water supplied to the potable water system in Hidalgo Del Parral, which comes from two main supply sources: wells from Valle del Verano, which provide water to the east side of the city, and the Water Treatment Plant, which receives water from different mines and supplies the west side of the city. When this plant is overcome on its capacity of treatment, a part of the water from the mines is fed directly to the northwest part of the city. The metals lead (Pb), chromium (Cr), cadmium (Cd), zinc (Zn), and arsenic (As) were analyzed by atomic absorption (AA) technique, based in the United States Environmental Protection Agency (EPA) Method 7000B (Revision 2, February 2007). The digestion process was done according to the guidelines established in Method NMX-AA-051- SCFI-2001, Analysis of Water-Determination of Metals by Atomic Absorption, developed by the National Standardization Technical Committee for Environmental Protection (Mexico). The samples were collected from the following points: 13 wells and 2 re-pumping stations of Valle del Verano, the inlet and outlet of the Water Treatment Plant and domestic faucets. The east side of the city, supplied by the wells of El Verano, is metal-pollution free. The water that comes from the mines contains high concentrations of As, Zn, Cd and Pb, with levels that can get to 0.12, 32.6, 0.26 and 3.5 mg/L, respectively. This water pollution generated by mining can be
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17 Lee mas

Water quality monitoring
pdf 2.43Mb

Water quality monitoring pdf 2.43Mb

The extent of the human activities that influence the environment has increased dramatically during the past few decades; terrestrial ecosystems, freshwater and marine environments and the atmosphere are all affected. Large-scale mining and fossil fuel burning have started to interfere measurably with natural hydrogeochemical cycles, resulting in a new generation of environmental problems. The scale of socio-economic activities, urbanisation, industrial operations and agricultural production, has reached the point where, in addition to interfering with natural processes within the same watershed, they also have a world-wide impact on water resources. As a result, very complex inter-relationships between socio-economic factors and natural hydrological and ecological conditions have developed. A pressing need has emerged for comprehensive and accurate assessments of trends in water quality, in order to raise awareness of the urgent need to address the consequences of present and future threats of contamination and to provide a basis for action at all levels. Reliable monitoring data are the indispensable basis for such assessments.
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348 Lee mas

Application of chemometric methods to water quality studies

Application of chemometric methods to water quality studies

Formation of trihalomethanes is shown to depend strongly on sev- eral environmental and/or operational water treatment plant vari- ables monitored during the disinfection processes. It has been concluded that trihalomethane formation takes place predominantly at three distinct locations of water treatment plants, i.e. after the fi rst pre-chlorination stage, after the carbon fi ltration stage – proba- bly due to desorption of already retained trihalomethanes – and after the post-chlorination stage. This formation also strongly de- pends on the quality of incoming raw water. One of the most impor- tant variables to be monitored in water treatment plants for trihalomethane formation predictions resulted to be input water tem- peratures at the beginning of the disinfection process and inside the plant. Some other variables associated to the organic matter quality, such as water oxidability and water conductivity resulted to be also important, as well as prechlorination, especially for the nonlinear models. Carbon fi lter aging, water turbidity after carbon fi lters, as well as the amount of input well water, UV absorbance, total organic carbon concentrations (the latter two after carbon fi lters) and post- chlorination variables were also con fi rmed to be important in both linear and nonlinear models. General improvement for external vali- dation predictions for the concentration of chloroform and bromoform was achieved with the inclusion of these new variables and with the use of nonlinear modeling methods, with prediction er- rors decreasing up to 10%, in comparison to previous application of linear modeling methods. Total trihalomethane concentration was the best predicted variable, followed by concentrations of mixed bromo – chloro trihalomethanes and chloroform. Bromoform concen- tration was still the worst predicted parameter, probably (at least in part) due to a lower precision of its reference values. Results obtained by K-PLS and SVR methods con fi rmed the presence of nonlinear interactions among the operational variables, and the vi- sualization of kernel transformations proved to be especially useful for this purpose.
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286 Lee mas

Quality assessment of irrigation water related to soil salinization in Tierra Nueva, San Luis Potosí, Mexico

Quality assessment of irrigation water related to soil salinization in Tierra Nueva, San Luis Potosí, Mexico

Soil salinization is a complex process resulting from the interaction of several factors, mainly quality of water used for irrigation, which deteriorates by aquifer overexploitation, and changes in rainfall patterns and aquifer recharge related to climate change. The purpose of this paper is to present a method to assess the variations of groundwater quality, to compare its suitability for irrigation and to decipher the pos- sible causes of soil salinity in Tierra Nueva, San Luis Potosí, Mexico. To assess salinization related to irrigation water quality, dissolved anions and cations were measured in surface and groundwater samples; the most widely used water quality indices to evaluate potential salinity risk of soils are Residual Sodium Carbonate (RSC) and Sodium Adsorption Ratio (SAR). In view of the limited number and uncertainty of using only two indices, in the present work a novel water quality assessment was applied for the first time by statistically combining eight individual quality indices: (RSC), (SAR), percentage of sodium (%Na), Kelley ratio (KR), permeability index (PI), soluble sodium percentage (SSP), magnesium adsorption ratio (MAR) and cation ratio of structural sta- bility (CROSS). A factorial variance analysis and principal component analysis of these eight indices were performed to identify linearity and maximum variance. All irrigation water tests show dissolved ions that can easily precipitate as indicated by PI. In cropland, %Na, SSP, RSC, KR and PI had values unsuitable for irrigation, while RAS, CROSS and MAR values are within suitable levels. The main mechanism of soil salinization seems to be the cation exchange of Ca 2+ to Na + in the waters,
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15 Lee mas

Contaminantes invisibles: los impactos ambientales, económicos y sociales como una amenaza para la calidad del agua

Contaminantes invisibles: los impactos ambientales, económicos y sociales como una amenaza para la calidad del agua

Water is a natural resource of indispensable usefulness to society as a whole. However, it is very limited, considering its use for human consumption. Clean fresh water that is suitable and of adequate quantity is of vital importance for the survival of all living organisms, as well as for the proper functioning of ecosystems, communities and economies (ANA, 2013. p. 18). However, the quality of water resources worldwide is under increasing threat, as human populations are growing and industrial and agricultural activities are expanding, in a scenario in which climate changes can cause major changes in the hydrological cycle. Low quality water endangers human health and ecosystems, reduces the availability of drinking water and resources for other purposes, limits economic productivity, and reduces the opportunities for development.
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12 Lee mas

Calibration models for the nutritional quality of fresh pastures by nearinfrared reflectance spectroscopy

Calibration models for the nutritional quality of fresh pastures by nearinfrared reflectance spectroscopy

ity of pasture silages (Ibáñez and Alomar, 2008; Restaino et al., 2009), as well as dried and fresh pastures (Cozzolino and Labandera, 2002; Alomar et al., 2009; Burns et al., 2013; Lobos-Ortega et al., 2013; Moscoso and Balocchi, 2016). It has also been used to evaluate how forage sample preparation affects nutrient composition analysis (Alomar et al., 2003), green forage intake and digestibility in ruminants (Decruyenaere et al., 2009), and water-soluble carbohydrates (WSC) in stolon samples of white clover (Inostroza et al., 2017). NIRS has also been used to characterize and quantify isoflavones and phenolic acid contents in red and white clover (Krähmer et al., 2013). Although NIRS is a quick and relatively low-cost technology, prediction equations for assessing nutritional quality have mostly been developed using leave-one-out cross validation (Garcia and Cozzolino, 2006; Ibáñez and Alomar, 2008; Alomar et al., 2009; Restaino et al., 2009; Burns et al., 2013). These equations do not typically utilize a independent test set to generate a robust model to predict an unknown pasture sample.
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9 Lee mas

Analysis of zoonotic microorganismspdf, 247kb

Analysis of zoonotic microorganismspdf, 247kb

At the beginning of the 20th century, Escherich noted that harmless, easily cultivated bacteria occurred in faeces. The organism was suggested for use as an indicator of the presence of faeces from warm-blooded animals in water. The practice of using Bacillus coli (later named Escherichia coli) as a measure of water quality was adopted, and, over the years, it was used in many forms, dependent on the practical methodology available. Coliforms, faecal coliforms, and E. coli were measured, respectively, over time as new specific methods became available. The measurement of E. coli in water served as evidence of the presence of faeces and even as a guide to how much faecal contamination was present. This approach appeared to work, because it was applied to waters near relatively small urban centres with poor infrastructure, little water treatment, and populations with little mobility. However, this approach to measuring water quality has been shown to have many inadequacies in identifying public health risk, no doubt related to extending its practical use to unintended applications that have never been validated.
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Applications of hydrodynamic and water quality models to the Sau and Boadella Reservoirs

Applications of hydrodynamic and water quality models to the Sau and Boadella Reservoirs

Temperature distribution is fundamental and crucial to understanding the performance and functioning of reservoir ecosystems (Kimmel et al. 1990). From a management point of view, it is usually preferable to practice selective withdrawal. The effects of water withdrawal have been found to be important in determining thermal stratification in reservoirs (Martin & Arneson 1978; Ford 1990). Surface withdrawal generally dissipates heat because the heated water layer is directly removed, and cooler, denser hypolimnetic water remains. In contrast, bottom withdrawal tends to store heat because removing cool hypolimnetic water results in an expansion of the epilimnion layer heated by solar radiation (Kennedy 1999). In addition, selectively releasing hypolimnetic water can lead to warming of the hypolimnion, and a decrease in the thermal stability of the water column. Decreased stability can promote vertical entrainment of nutrients in the epilimnion (Effler et al. 1986). From a water quality point of view, selective withdrawal of hypolimnetic water is better because it can increase the net export of phosphorus from anoxic reservoirs (Martin & Arneson 1978). A shortened hypolimnetic residence time could also reduce the potential for the development of anaerobic conditions, thereby reducing phosphorus release even further (Cooke et al. 1993). Indicator factors such as nutrient availability are important for determining phytoplankton distribution (Cottingham et al. 1998; Vrede et al. 1999).
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157 Lee mas

Effect of the addition of soluble (nutriose, inulin and polydextrose) and insoluble (bamboo, potato and pea) fibres on the quality of sugar snap cookies

Effect of the addition of soluble (nutriose, inulin and polydextrose) and insoluble (bamboo, potato and pea) fibres on the quality of sugar snap cookies

The rheological behaviour of doughs was studied using a Thermo Scientific HaakeRheoStress 1 controlled strain rheometer (Thermo Fisher Scientific, Schwerte, Germany) and a Phoenix II P1- C25P water bath that controlled analysis temperature (set at 25ºC). The rheometer was equipped with parallel-plate geometry (60-mm diameter titanium serrated plate-PP60 Ti) with a 3-mm gap. After adjustment to the 3-mm gap, the excess dough was removed and vaseline oil (Panreac, Panreac Química SA, Castellar del Vallés, Spain) was applied to cover the exposed sample surface. During the oscillatory tests, the dough was left to rest for 800 seconds before measuring. First, a strain sweep test was performed in duplicate at 25ºC with a stress range of 0.1–100 Pa at a constant frequency of 1 Hz to identify the linear viscoelastic region (LVR). On the basis of the results obtained, a stress value included in the linear viscoelastic region (3 to 20 Pa) was used in a frequency sweep test at 25ºC with a frequency range of 10–0.1 Hz. Values of elastic modulus (G’ [Pa]), viscous modulus (G’’ [Pa]), complex modulus (G*) (G’+i·G”) and tangent delta (Tan δ) (G’’/G’) were obtained for different frequency values (ω [Hz]) and analysed for1 Hz (Dobraszczyk and Morgenstern, 2003). Samples were analysed in duplicate. Cookie properties
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13 Lee mas

Full PDF

Full PDF

Abstract: The brachyuran crabs are iteroparous species which present a high diversification of reproduction patterns, which may have evolved as a species-specific response to environmental conditions. Tropical spe- cies commonly present a year-round reproduction due to stable environment conditions. Goniopsis cruentata is a crab species widely distributed along the Western Atlantic, inhabiting practically every microhabitat in the mangrove ecosystem. The aim of the present study is to determine the breeding period of the crab Goniopsis cruentata in Northeastern Brazil and also to evaluate the influence of water salinity, rainfall and air and water temperature on it. A total of 71 ovigerous females, captured from August-2007 to July-2008, were used to assess the breeding period of this species. It was analyzed by the monthly proportion of ovigerous females. A correla- tion was applied to verify the influence of the abiotic factors on the breeding period. The present population bred seasonal-continuously with peaks in the dry period, which was not associated with monthly variations of salinity, rainfall and air and water temperatures. Therefore, according to statistical analyses, our hypothesis was refuted. However, breeding was intensified in the dry period, when salinity and temperatures were higher and rainfall was lower. We conclude that, even though breeding is not related to monthly variation of environmental factors, it occurs in periods of higher salinity and temperatures and lower rainfall. Rev. Biol. Trop. 61 (1): 29-38. Epub 2013 March 01.
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Relacin entre apoyo social y bienestar fsico y mental del anciano con diabetes

Relacin entre apoyo social y bienestar fsico y mental del anciano con diabetes

We undertook a population-based cross sectional study with type 2 diabetes patients aged 55 years and older, who lived in southeastern Mexico City. Participants were selected by random sampling from the listing of diabetic patients kept by the IMSS Family Medicine Units issued by the IMSS Epidemiology Surveillance System. We estimated the sample size by considering the number of subjects needed to prove the study hypotheses about the relationships between social support and quality of life, depressive symptoms and fasting glucose levels. A representative sample of 705 individuals was used; and all participants signed informed consent forms. Information was collected from two sources: a questionnaire purposely designed for this study and
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9 Lee mas

Sugar cane bagasse prehydrolysis using hot water

Sugar cane bagasse prehydrolysis using hot water

Abstract - Results are presented on the hot water prehydrolysis of sugar cane bagasse for obtaining ethanol by fermentation. The experimental study consisted of the determination of the effect of temperature and time of prehydrolysis on the extraction of hemicelluloses, with the objective of selecting the best operating conditions that lead to increased yield of extraction with a low formation of inhibitors. The study, carried out in a pilot plant scale rotational digester, using a 3 2 experimental design at temperatures of 150-190°C and
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8 Lee mas

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PCA was applied to the normalized data to compare the compositional patterns between the analysed water samples and to identify the factors that in- fluence each one. Results of PCA are summarized in Table 3. There are several criteria to identify the number of PCs to be retained in order to understand the underlying data structure (Chen et al. 2007). In the present study, all the PCs with eigenvalues equal to or greater than 1.0 were used. Thus, four PCs with eigenvalues > 1 were retained, explaining the 93 % of the total variance in the water quality data set. The first PC (PC1) accounting for 59.65 % of the to- tal variance, had positive loadings for WT, EC, TDS, HCO 3 , SO 4 , Cl, Na, K, Ca, Mg, F, T-Hard, T-Alk, and RAS. This PC can be related to natural sources of the ionic groups of salts in the basin of the reservoir from inflows, soil weathering and runoff, so this PC was defined as the “mineral” component.
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12 Lee mas

TítuloModern physico chemical analysis of drinking water from Ceyranbatan reservoir (Azerbaijan)

TítuloModern physico chemical analysis of drinking water from Ceyranbatan reservoir (Azerbaijan)

For the normal life and health of the population of each country becomes important at the present time, the quality and ecological assessment of water. Water is essential for normal physiological processes of the body. Due to the need to identify specific physico-chemical parameters of water and to carry out a comprehensive assessment of the state of drinking water in Absheron region in Azerbaijan, as research object was chosen the Ceyranbatan reservoir. The study was conducted to evaluate the chemical composition, as well as its compliance with drinking water quality standards.
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25 Lee mas

Drinking-water quality control in small-community supplies

Drinking-water quality control in small-community supplies

Both water-quality control testing and testing by the surveillance agency should be applied to all the types of water available to the community, e.g., piped or un[r]

136 Lee mas

Para descargar el documento haz clic AQUI

Para descargar el documento haz clic AQUI

Soil solids, comprising inorganic and organic components, form the matrix or the body of most soils. This matrix, or the visible part of the soil, is the storehouse of water and nutrient elements (e.g., N, P, K, Ca, Mg, Zn, Cu, etc.). It is also the site of most processes that govern soils buffering and filtering capacity, and life support capability. The buffering capacity of the soil refers to its ability to withstand or to adapt to sudden perturbations such as in soil reaction (i.e., pH). The filtering capacity refers to soil’s ability to remove pollutants (e.g., pathogens or chemicals including heavy metals) out of the water percolating through the soil by denaturing pollutants or mechanical sieving of suspended particles. Both buffering and filtering capacities depend on soil’s reactivity. The latter refers to chemical, physical, and biological reactions in soil and depends on its nature (e.g., relative proportion of the inorganic and organic components, coarse or fine size, small or large surface area, and low or high charge density). Soil quality is determined by these and other properties of soil solids, which in turn moderate the soil’s ability to support plant and animal life. Soil’s life support capability depends on processes that govern productivity, elemental cycling, and environment quality (see Chapter 1).
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699 Lee mas

Evaluacion de la Calidad Linked Open Data basada en un Modelo de Lógica Difusa

Evaluacion de la Calidad Linked Open Data basada en un Modelo de Lógica Difusa

Abstract. Linked Open Data has been one of the most widely used online data publishing methods in recent years. This growth means that the quality of this data is required for the benefit of consumers and people who wish to use this data. There are approaches based on classical mathematical models, however, most of these results are too linear; that is, they use conventional evaluators to de fi ne both quality aspects and results. In response, a new approach based on fuzzy logic is constructed as an application, which aims to complement and compare traditional models without the need to restrict the quality aspects with which it can be measured. As a methodology, it is done by obtaining data from each dataset through the SPARQL Endpoints provided by high category data- sets, classifying them within accessibility and trust dimensions, represented in 4 values: response time, scalability, trustworthiness and timeliness. This analysis is done internally for the values within the accessibility dimension, and exter- nally for the values within the confidence dimension. In this way, it is possible to know or determine a better general quality approximation of the Linked Open Data according to a large number of quality evaluation variables, or even parameterize its own aspects in the model as a complement to the already established models, through the concept of fuzzy logic.
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12 Lee mas

The use of the fluorescente for the study of the water quality

The use of the fluorescente for the study of the water quality

A working group headed by the Polytechnic University of Madrid, and through the University of Santiago de Compostela, presented a proposal to study the viability of an airborne instru[r]

5 Lee mas

Desarrollo, género y el derecho humano al agua. Un estudio comparativo en Hidalgo, México.

Desarrollo, género y el derecho humano al agua. Un estudio comparativo en Hidalgo, México.

This study confirms that economic growth produces and recreates new inequalities between men and women, rich and poor, as well as between different regions inside a country or a state. Beyond formal democracy, the expansion of the portfolio of human rights keeps alive the hope of reducing these inequalities. A pre-condition for this to happen is to divulge very broadly the contents of the human right to water among the populations most affected by problems of service, availability, quality and inefficiency in management described in this work. There is no indicator of economic performance that could compensate for the water vulnerability that women experience in Hidalgo and, particularly, in CV, when facing the lack of safe, affordable and quality water. It is very likely that this situation is repeated in other parts of the country. According to the constitution, it is the responsibility of the State to guarantee the human right to water of Mexican citizens. It is still pending to perform more research work, as well as correlation and dissemination, for the rights attained on paper to be translated into actual benefits for rural women in Hidalgo and the rest of México.
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