Reduction In Electrical Conductivity Research Articles

Early udder inflammation in dairy cows treated by a homeopathic medicine (Dolisovet®): a prospective observational pilot study

Mammary inflammation in dairy cows is a widespread problem in dairy farming resulting in significant economic and welfare concerns. Dolisovet (Belladonna 1dH, Calendula MT, Echinacea 1dH, Dulcamara 1cH) a homeopathic medicine, licensed in France and indicated for the restoration of mammary function in cows is presented as a 10 g tube of ointment for intramammary use. A prospective, uncontrolled, observational pilot study involving the collection and analysis of data from 31 udder quarters identified as being inflamed by an automated milking system (AMS) was conducted to evaluate the effect of Dolisovet on selected parameters of mammary inflammation. Inflamed quarters were identified when milk quality started to deteriorate, via an alert generated by the AMS, on the basis of electrical conductivity (EC). Milk yield and EC were retrieved five to seven days prior to the AMS alert, on the day of and for the following seven days. Dolisovet was administered twice daily for two consecutive days, commencing on the day of the AMS alert. A significant reduction in EC was observed 4-7 days following the first treatment. An increase in milk yield was also observed following the first treatment. Dolisovet may have a beneficial therapeutic effect in the early stages of udder inflammation and for restoring udder health and function. This medicine may be an effective first line treatment for sub-clinical bovine mastitis, reducing the need for antibiotics. Randomised, controlled studies should be undertaken to further investigate this possibility.

Alteration of acid sulphate soil solution chemistry with liming and washing in disturbed columns

Soil acidity is on of the main factors which limit production of tropical acid sulfate soils, being the correction with liming and washing slow. The aim of this research was to evaluate the effect of liming and washing on the chemical characteristics, pH, electric conductivity, sulfates, calcium and magnesium content of lixiviates in an acid sulfate soil (franc isohipertermico typic sulfaquepts) from San Carlos, Cordoba, Colombia. Lysimeters, 15cm of diameter x 80cm of height were installed, and filled with soil collected from the surface horizon, 0 -20 and 20 - 40cm, limed with 0, 2, 4, 6, 8 and 10t/ha, and washed with 15L of water, equivalent to three pore volumens. The research was carried out with a randomized block design with four replications, in a hothouse of the University of Cordoba, Colombia. The evaluated variables were pH, electrical conductivity (EC), sulfates, calcium and magnesium contents in the leaching. A small increase in pH due to liming was detected, as well as a reduction in EC; however, liming and washing did not increase the lixivation of sulfates, calcium and magnesium. Regressions models were obtained, which permitted to, approximately, estimate 10t/ha lime to increase pH to 5 and to reduce EC to 2dS/m.

CONDUCTIVITY OF DONKEY MILK

The electrical conductivity (EC) of milk is considered as one of the most important parameters which supports the diagnosis of mastitis in cows.Milk ions have a considerable influence on EC and their concentrations vary depending on animal species, season, lactation stage, etc. Some components of milk can change the EC, e.g. lactose. A negative correlation between EC values and the concentration of lactose is noticed, as a consequence of the inverse relation between this disaccharide and the chlorine content in milk. Fat and casein contents exert some influence on the EC, too. This study provides preliminary results on the physiological EC values in donkey milk and aims to highlight any correlation with some of its chemical-physical parameters and Somatic Cell Count (SCC). Mean EC value in donkey milk was found to be 3.57 mS. Statistically significant correlations were found between EC and SCC (r = 0.57 , p < 0.01) and between EC and (r = 0.30 , p < 0.05). The EC and lactose were not correlated although a reduction of EC was often observed when the lactose content increased, as reported in the literature for bovine milk. According to the EC can be considered as a reliable parameter to identify any breast disorder, taking into account the physiological factors that influence EC.

Effect of Mid-day Reduction of High Electrical Conductivity Treatment on the Yield and Quality of Greenhouse Cherry Tomato

Cherry tomato (Solanum lycopersicum var. cerasiforme) plants were grown hydroponically with three different regimes of electrical conductivity (EC) of the nutrient solution to develop an effective EC management method to enhance the fruit quality. The EC treatments examined were 1) continuous high EC [4.7 dS·m−1 (HE)], 2) continuous low EC [2.8 dS·m−1 (LE)], and 3) high EC combined with midday (1030–1530 hr) low EC [midday reduction of high EC (MDR)]. The research was conducted to obtain preliminary information on the effect of EC treatments on the yield and fruit quality for 15 weeks of harvest under semiarid greenhouse conditions. Harvested fruit were sorted to several quality grades, including the “premium” grade based on fruit size, color, and total soluble solids. The number of fruit per truss was significantly higher in cultivar L308 than in cultivar L907 and in the LE treatment than in the HE or MDR treatment. The fruit size decreased over time regardless of EC treatment and cultivar. Cumulative yield of 15 weeks was greater in the LE treatment (26.3 kg·m−2) than in the HE treatment (22.1 kg·m−2) for ‘L907’, and there were no significant differences between the three EC treatments for ‘L308’ (24.1–28.1 kg·m−2). The cumulative yield in the MDR treatment was similar to that in the LE treatment regardless of cultivar. When quality attributes such as total soluble solids concentration measured for randomly sampled fruit were considered, cumulative premium-grade yield was the greatest for the HE treatment (12.9 or 17.6 kg·m−2) and was the smallest for the LE treatment (1.4 or 12.1 kg·m−2), regardless of cultivar. The cumulative yield of premium-grade cherry tomatoes in the MDR treatment was not significantly different from that in the HE treatment for ‘L308’ but was 11% less than that in the HE treatment for ‘L907’. Therefore, together with cultivar selection, the MDR treatment may be a potential alternative to a more commonly practiced continuously high EC treatment in semiarid greenhouses with limited environmental control capacity in which increasing the nutrient EC to increase quality is desired without significantly decreasing yield.

Classification of springs of Jeju Island using cluster analysis of annual fluctuations in discharge variables: investigation of the regional groundwater system

The springs of Jeju Island have been studied since 1999. However, previous studies did not provide a systematic analysis of survey results. Thus, we performed a systematic analysis of the groundwater flow system using cluster analysis of discharge variables, i.e., discharge rate, electrical conductivity (EC), and temperature, at 121 springs. The 121 springs were categorized into nine major groups based on discharge rates and ten groups based on EC. Springs in groups 1, 2, and 3 in discharge cases had peak discharge rates in September, October, and occasionally in November, following the rainy season. Other springs showed complex seasonal variation in discharge rates. Springs in groups 4–1, 4–3, 5–2, 9–1, and 9–2 had peak discharge rates in winter (December–February). The results of classification by EC were directly correlated with the absolute values of and seasonal variation in EC. Based on EC, springs in group 1 had relatively low EC of > 500 μS/cm in general. The highest EC at each spring in group 1 was 110–18,000 μS/cm. Coastal springs generally had higher EC than did springs located inland. The relation between discharge rate and EC was of interest. At some springs, discharge rate and EC were proportional, especially in winter. The proportionality between discharge and EC cannot be explained by the conventional groundwater management model of Jeju Island. To explain this proportionality, we examined the results of previous studies with regard to geological features, well locations, hydraulic head and hydraulic gradient distributions, and vertical reduction in groundwater EC within the zone influenced by saline water. We then proposed a hypothetical regional conceptual model of groundwater flow for Jeju Island. More precise studies are needed to clarify the relationships among responses at surveyed springs, hydraulic features in coastal areas, and the regional conceptual model for groundwater circulation on Jeju Island.

Electrical Conductivity and Chloride Reduction in Leachate Treatment Systems

Chloride is used as conservative tracers to estimate hydrological pathways. Field data on treatment of municipal solid waste (MSW) leachate show that Cl is reduced in aerobic treatment. Here laboratory experiments simulating MSW leachate treatment are conducted to see if electrical conductivity (EC) reduction can be duplicated in the laboratory, and to find probable chemical or physical factors explaining EC and chloride reduction. The experiments include three leachate, eight artificial, and three control samples. Mean reduction of EC in the respirometers was 17% for the leachate and 25% in the artificial samples. There was close to zero reduction in the controls. Mean reduction of chloride was 45% in the artificial samples and 9% in the controls. The oxygen consumption was lower in the leachate samples during aeration, probably due to inhibitory compounds. There was no reduction in EC after chemical coagulation with Al and organic coagulants, 31% reduction in the aerobic system, and 46% in the anaerobic system. Total organic carbon significantly influenced the oxygen consumption. The reduction of chloride and EC depended on the acidity (pH) of the leachate. Centrifugation showed an effect on EC and chloride concentration. Based on these results it seems that the reduction of chloride in leachate treatment depends on the formation of organic precipitates.

Temporal evolution of salts in Mediterranean soils transect under different climatic conditions

The research was conducted in Israel at three sites along a south–north axis, characterized by increasing annual rainfall, from 310 mm at site LAV in the south through 600 mm at site MAT (600), to 800 mm at site EIN in the north. At each site soil samples were taken during several seasons (September 2001 through April 2003), in three dominant microenvironments at 0–2 cm and 5–10 cm. The following microenvironments were selected at LAV and MAT: “Under Shrub” (US), “Between Shrubs” (BS), and “Under Rock fragments” (UR). At EIN the selected microenvironments were US, BS, and “Under Tree” (UT). In each soil sample electrical conductivity (EC), pH, and concentrations of several ions were determined. The objective was to analyze the effects of soil microenvironments and climatic conditions on the temporal dynamics of salt concentrations. In all microenvironments at all sites the minimal values of EC were found in the rainy season (January or April), and the maximal values in the dry season (September). In the rainy season the temporal variability of EC in the topsoil was regulated by: (1) clay, which restricted the leaching of salts from the topsoil when EC was low; and (2) surface features (microenvironment), when EC was high. In the UT, US, and UR microenvironments the rainy season could be divided into two periods with respect to their effect on salt movement in the topsoil: at the beginning of the rainy season (September–January) the reduction in EC was relatively moderate, especially with regard to ions involved in biotic activity (Mg ++ and K +), whereas, late in the rainy season (January–April) there was enhanced reduction in EC. In contrast, in BS the regulation of salt movement was weak at all sites. Hence, in this microenvironment the salts concentration (mainly Na + and Cl −) responded rapidly to changes in rain amount and soil moisture and temperature. In the dry season (April–September) the temporal variation in EC varied not only between microenvironments but also between sites. In US, where local surface features were similar at all sites (the same shrub), the rise in EC was maximal at LAV (mainly Ca ++ and Na +), and gradually diminished toward EIN. Thus, the contribution of regional sources to the salts added to the soil diminished toward the humid site, EIN, where the EC hardly changed in any microenvironment. In BS and UR microenvironments the rise in EC (mainly in Ca ++, Na +, and K +) was greatest at site MAT, and decreased toward LAV and EIN. It seems that this pattern was affected also by changes in local biotic activity.

English

Relationships between electrical conductivity (EC) and sodium adsorption ratio (SAR) in reconstructed soils at surface coal mining operations are poorly documented in the literature. Research has focused primarily on agricultural and range soils. Chemical and physical properties of reconstructed soils are unique and quite different from natural soils formed over hundreds of years through pedogenic processes. These differences largely occur because relatively unweathered overburden is exposed during mining processes and subsequently used as a lower root-zone medium (minesoil) during soil reconstruction. Some of these materials are classified as sodic and therefore are considered unsuitable rooting media for establishment of native vegetation. Weatherable minerals (i.e., pyrite, calcite, gypsum, and other geologic substrates) present in minesoils can effectively remediate or mitigate an elevated SAR condition by maintaining EC levels in the soil solution to promote clay particle stability and by providing sources of exchangeable calcium and magnesium. Coversoil (e.g., topsoil) enhances remediation through physical and chemical buffering between sodic root-zone material and the reconstructed soil surface. A laboratory core-study was used to evaluate weathering potential of 10 minesoil materials from three mining operations in the Southwestern United States. Cores were prepared with 15 cm of coversoil over 30 cm of minesoil and subjected to simulated precipitation. Chemical evaluations of weathered materials show significant reductions in EC and SAR and overall improvement of minesoil quality. Chemistry of drainage water from three coversoils shows these materials behave as a chemical buffer above the underlying sodic materials. Coversoils provide a source of calcium and other electrolytes that promote physical stability and enhance remediation of sodic minesoil materials.