Low Electrical Conductivity Values Research Articles

New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity

Highly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT ~ 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)3·5H2O separately and in a mixture. Two methods to synthesise the same material were examined: (a) free sintering of an initially reduced powder and (b) PECS. The free-sintered materials with higher porosities (up to ~ 40%) exhibited lower values of electrical conductivity than the dense PECS samples (porosity up to ~ 5%), but the benefit of an even sixfold reduction in thermal conductivity resulted in higher ZT values. The theoretical values of thermal conductivity for various effective media models considering randomly oriented spheroid pores are in good agreement with the experimental thermal conductivity data. The assumed distribution and shape of the pores correlated well with the scanning electron microscope analysis of the microstructure. The lowest value of thermal conductivity, equal to 0.5 W/m K, was measured at 523 K for In0.1Co4Sb12 with 41% porosity. The highest value of ZTmax = 1.0 at 673 K was found for the In0.2Co4Sb12 sample in which the porosity was 36%.Graphic abstract

Improvement in seed germination by priming treatments in Black nightshade (Solanum nigrum L.)

The seeds must be viable and non-dormant for the efficient cultivation of the species of medicinal plants. The seeds of Solanum nigrum possess primary dormancy, which restricts germination. Hence, a laboratory experiment was conducted during 2019 in the Department of Seed Science and Technology, Agricultural College and Research Institute, Madurai, Tamil Nadu. The S. nigrum seeds were primed by soaking in different chemicals viz.,GA3 100ppm, Thiourea1%, KNO3 0.5%, Succinic acid 100 ppm, Ascorbic acid 100 ppm, hydro and dry control with soaking durations of 12h and seeds were dried under shade to bring back to their original moisture content and used for assessing the seed quality studies. The results revealed that among the different priming treatments Thiourea 1% recorded higher seed quality parameters viz, speed of germination (5.6), germination (88 %), seedling length (5.92 cm) and vigour index (520) and the enzyme activity of dehydrogenase (0.072 OD value) and lower values of electrical conductivity( 0.027 dsm-1), amino acids (0.119 ?gg-1 ) and sugars ( 0.175 ?gg-1 ). Hence it could be recommended as pre-sowingg seed priming treatment in S. nigrum.

Selection of superplasticisers for improving the rheological and mechanical properties of cement paste with CNTs

Electrical conductivity (EC), pH, spreadability, viscosity, and temperature measurements were used to evaluate the impact of superplasticiser (SP) (lignosulphonates (A),polyacrylates (B), polycarboxylates (C)) on the cement paste with CNTs properties.Compared to the pure paste’s viscosity,SP(A), characterised with high EC values, causes the rise in the paste temperature and viscosity, but SP(C) and SP(B), with lower EC values, reduce the specified parameters. While interacting with CNTs, SP(C), SP(B) and SP(C + B) blend, lowers paste initial temperature, longer structure formation and hydration process. When SP(A)is used, the aforementioned processes take place in an opposite way. By interaction with CNTs and SP(A), more of ettringite and less of portlandite than in the other samples is formed. DTA/TGstudy confirmed that at least 2.4% of portlandite is formed in a sample with SP(A), more than 3.1% and 3.4% in samples with SP(C) and SP(B), and4.1%in sample withSP(C + B).In the samples with a blend of SP and CNTs, the gain of compressive strength was achieved - up to 20%after 28 days of curing, in comparison to the samples with separately used SP’s, this could be related to the interaction effect between the CNTs and the blend of SP.

Seed Vigor Changes of Forage Pea Cultivars Based on Seed Color

This study aimed to determine whether there were the differences for germination performance and seed vigor among the seed colors (Brown, green and army green) in forage pea cultivars (Ozkaynak, Tore and Taskent) after harvest. Second day germination percentage, final germination percentage (FGP), mean germination time (MGT), shoot length (SL), root length (RL), seedling fresh (SFW) and dry weight (SDW) were measured. The seed vigor tests, electrical conductivity (EC) and accelerated ageing (AA) conducted at 42°C for 48 h were used for distinguishing the vigor of seed colors in forage pea cultivars. The results showed that the final germination percentage was not significantly changed with seed color and cultivar while 2 nd day germination was recorded in cv. Tore and army green seeds. Army green colored seeds germinated faster than brown ones. Among three genotypes, cv. Tore had the highest final germination percentage, shoot length, seedling fresh and dry weights, and the earlier time to germination. There were significant differences among seed colors and army green and green seeds produced more vigorous seedling than brown seeds. The EC and AA tests confirmed that vigorous germination and seedling growth were obtained from green colored seeds in forage pea. Lower EC values and higher germination performance in AA test were recorded in army green and green seeds. It was concluded that the forage pea seeds after harvest should be sorted for seed color and removing of brown seeds may be beneficial for improving seeds quality for their high seed vigor and seedling growth ability.

Spatial Forecasting of Dissolved Oxygen Concentration in the Eastern Black Sea Basin, Turkey

The aim of this study was to model, as well as monitor and assess the surface water quality in the Eastern Black Sea (EBS) Basin stream, Turkey. The water-quality indicators monitored monthly for the seven streams were water temperature (WT), pH, total dissolved solids (TDS), and electrical conductivity (EC), as well as luminescent dissolved oxygen (LDO) concentration and saturation. Based on an 18-month data monitoring, the surface water quality variation was spatially and temporally evaluated with reference to the Turkish Surface Water Quality Regulation. First, the teaching–learning based optimization (TLBO) algorithm and conventional regression analysis (CRA) were applied to three different regression forms, i.e., exponential, power, and linear functions, to predict LDO concentrations. Then, the multivariate adaptive regression splines (MARS) method was employed and three performance measures, namely, mean absolute error (MAE), root means square error (RMSE), and Nash Sutcliffe coefficient of efficiency (NSCE) were used to evaluate the performances of the MARS, TLBO, and CRA methods. The monitoring results revealed that all streams showed the same trend in that lower WT values in the winter months resulted in higher LDO concentrations, while higher WT values in summer led to lower LDO concentrations. Similarly, autumn, which presented the higher TDS concentrations brought about higher EC values, while spring, which presented the lower TDS concentrations gave rise to lower EC values. It was concluded that the water quality of the streams in the EBS basin was high-quality water in terms of the parameters monitored in situ, of which the LDO concentration varied from 9.13 to 10.12 mg/L in summer and from 12.31 to 13.26 mg/L in winter. When the prediction accuracies of the three models were compared, it was seen that the MARS method provided more successful results than the other methods. The results of the TLBO and the CRA methods were very close to each other. The RMSE, MAE, and NSCE values were 0.2599 mg/L, 0.2125 mg/L, and 0.9645, respectively, for the best MARS model, while these values were 0.4167 mg/L, 0.3068 mg/L, and 0.9086, respectively, for the best TLBO and CRA models. In general, the LDO concentration could be successfully predicted using the MARS method with various input combinations of WT, EC, and pH variables.

The Pilato Lake (Sibillini Mts., Central Italy): first results of a study on the supposed variations of its hydrogeological conditions induced by the seismic sequence 2016-2017

The Pilato Lake has glacial origin, is located in the Sibillini Mountains, Central Italy, and is characterized by the endemism of the small crustaceous Chirocephalus marchesonii. In the context of a research agreement with the Monti Sibillini National Park, the ISPRA Geological Survey of Italy is carrying on some studies aimed to evaluate the supposed effects of the 2016–2017 Central Italy earthquakes on the hydrogeological conditions controlling the lake’s evolution. The study, started in July 2018, aims primarily at the reconstruction of the geological and hydrogeological subsoil setting, beneath the valley hosting the lake. In order to define the conceptual model of groundwater circulation and, thus, to evaluate the emptying and recharge seasonal cycle of the lake, hydrogeological surveys and geophysical investigations were performed. The research program is still in progress and only preliminary results may be proposed. The hydrogeological surveys demonstrate the absence of geomorphological evidence of seismic-induced surface fractures generated by the seismic sequence 2016-2017. Consequently, the complete drying of the lake, occurred in summer 2017, was probably due to meteoclimatic reasons and/ or to not yet verified variations in the permeability characteristics of the surficial deposits and/or bedrock affecting the infiltration towards the subsoil, caused by the severe seismic shaking. The low electrical conductivity values of the lake’s waters are in accordance with the prevailing origin of the lake’s recharge by snow melting and direct rainfall. As concerns the first geophysical surveys in the Pilato Lake area, seismic surveys by surface wave method assessed that the maximum thickness of debris here estimated is about 12.5-14 m. As a whole, the factors responsible for the progressive lowering of the lake level are: i) the water overflow through the Fonte del Lago spring, ii) the evaporation from the lake surface and iii) the drainage through the scarcely permeable glacial deposits towards the Basal Calcareous Aquifer, hosted within the limestone at lower altitude.

Soil Morphology, Physico-chemical Properties, Classification and Potential of Selected Soils in Kenya

Four soil profiles (Yala, Galana, Baringo and Bondo) that represent different ecology, physiography and pedological variability were described to study their morphology, soil physico-chemical characteristics and to classify them using two internationally known soil classification systems. Soil samples were taken from designated pedogenic horizons for physical and chemical analysis in the laboratory. These soils are deep to very deep (> 110 cm) and well-drained except in Galana which was imperfectly drained, with varying textures. In Bondo, the soils are moderately acid (pH 5.6 – 6). In Baringo, the soil profile is acidic (< 5.0) while in Galana moderately alkaline (pH 7.3 - 8.3) and Yala soils are moderate to strongly acid (5.1 - 5.7). The organic carbon (< 0.6%) and organic matter levels (1 – 2%) were low and decreased down the profiles in all. The soils have low to moderate fertility. The base saturation of the studied soils is rated as very high (> 80%) in Galana and Baringo and low (< 50%) in Yala and Bondo pedons. The soils are non-saline as indicated by the low values of electrical conductivity (< 1.7dS/m) in the pedons. The soils are non-sodic (ESP < 6%) in Bondo and Yala, however moderately sodic (ESP 11-15%) in Galana and Baringo. Ochric horizon was the main diagnostic epipedon while ferralic, argillic and cambic horizons were the diagnostic B horizons. According to USDA Soil Taxonomy, the soils were classified as Typic Haplustox (Yala), Typic Haplocalcids (Galana), Typic Eutrudepts (Baringo) and Plinthic Haplustults (Bondo) corresponding to Haplic Ferralsols, Luvic Calcisols, Haplic Cambisol and Cutanic Plinthic Acrisols in the WRB for Soil Resources. The general fertility of the soils of the areas is discussed highlighting their potentials and constraints.

Conductive Carbon Materials from the Hydrothermal Carbonization of Vineyard Residues for the Application in Electrochemical Double-Layer Capacitors (EDLCs) and Direct Carbon Fuel Cells (DCFCs).

This study investigates the production of bio-based carbon materials for energy storage and conversion devices based on two different vineyard residues (pruning, pomace) and cellulose as a model biomass. Three different char categories were produced via pyrolysis at 900 °C for 2 h (biochars, BC), hydrothermal carbonization (HTC) (at 220, 240 or 260 °C) with different reaction times (60, 120 or 300 min) (hydrochars, HC), or HTC plus pyrolysis (pyrolyzed hydrochars, PHC). Physicochemical, structural, and electrical properties of the chars were assessed by elemental and proximate analysis, gas adsorption surface analysis with N2 and CO2, compression ratio, bulk density, and electrical conductivity (EC) measurements. Thermogravimetric analysis allowed conclusions to be made about the thermochemical conversion processes. Taking into consideration the required material properties for the application in electrochemical double-layer capacitors (EDLC) or in a direct carbon fuel cell (DCFC), the suitability of the obtained materials for each application is discussed. Promising materials with surface areas up to 711 m2 g−1 and presence of microporosity have been produced. It is shown that HTC plus pyrolysis from cellulose and pruning leads to better properties regarding aromatic carbon structures, carbon content (>90 wt.%), EC (up to 179 S m−1), and porosity compared to one-step treatments, resulting in suitable materials for an EDLC application. The one-step pyrolysis process and the resulting chars with lower carbon contents and low EC values between 51 and 56 S m−1 are preferred for DCFC applications. To conclude, biomass potentials can be exploited by producing tailored biomass-derived carbon materials via different carbonization processes for a wide range of applications in the field of energy storage and conversion.

Assessment of trace metal contamination in peri-urban soils in the region of Kenitra - Morocco

<p>The spatial distribution of trace metals in peri-urban soils from Kenitra city (Morocco) was investigated. A total of 10 soil samples (0-20 cm depth) were collected from the studied area. The physicochemical properties including pH, electrical conductivity and texture were determined. Contents of 6 trace metals (Cd, Cr, Cu, Ni, Zn and Pb) were measured using Atomic Absorption Spectrometry method (AAS). <strong></strong></p><p>The results showed that soils of Kenitra city have a sandy texture with a predominance of alkaline pH. The analyzed soil samples can be considered as no salt due to low electrical conductivity values. The trace metals contents revealed that soils are uncontaminated.</p>

Assessment of trace metal contamination in peri-urban soils in the region of Kenitra - Morocco

The spatial distribution of trace metals in peri-urban soils from Kenitra city (Morocco) was investigated. A total of 10 soil samples (0-20 cm depth) were collected from the studied area. The physicochemical properties including pH, electrical conductivity and texture were determined. Contents of 6 trace metals (Cd, Cr, Cu, Ni, Zn and Pb) were measured using Atomic Absorption Spectrometry method (AAS). The results showed that soils of Kenitra city have a sandy texture with a predominance of alkaline pH. The analyzed soil samples can be considered as no salt due to low electrical conductivity values. The trace metals contents revealed that soils are uncontaminated.

Field evaluation of a new hydroxyapatite based binder for ex-situ solidification/stabilization of a heavy metal contaminated site soil around a Pb-Zn smelter

Abstract This study presents a field trial of ex-situ solidification/stabilization of heavy metal contaminated soils using a new hydroxyapatite based binder SPC (superphosphate and calcium oxide). The field performance including electrical conductivity (EC), heavy metal and chemical oxygen demand (COD) leachability, and penetration resistance of stabilized soils up to 256 days after treatment is investigated. Moreover, acid neutralization capacity (ANC), metal speciation, and soil mineralogy analyses are performed to elucidate the heavy metal immobilization mechanisms. The results indicate that the stabilized soils have lower EC values than untreated soils, indicating the lower soluble salt contents in stabilized soils. Ex-situ treatment can significantly reduce acid soluble fraction contents and leachability of lead, zinc and cadmium in soils as a consequence. Decrease in COD leachability is observed during the curing period up to 256 days. Additionally, SPC stabilized soils give superior mechanical properties as indicated by their higher penetration resistance values as compared to the untreated soils. The improvement in ANC and reduction in acid soluble fraction resulting from the formation of phosphate-based precipitates are mainly responsible for the reduced heavy metal leachability of stabilized soils. Additionally, ex-situ SPC treatment is found to be effective in improving soil spatial homogeneity.

Can geophysics and geochemistry combine to detect mineralisation under transported cover?

The oxidation of Fe-containing sulfide mineralization can lead to the development of natural galvanic cells that are characterized by a reduced acid chimney above the mineralization itself and pH-redox controlled chemical haloes surrounding the chimney. Such chimneys may extend through overlying transported regolith cover of varying thicknesses and composition, altering regolith mineralogy (changes to clays, loss of carbonates), element distribution patterns and geophysical characteristics such as electrical conductivity (EC). This paper compares EM and geochemical profiles in transported regolith over porphyry style Au-Mo-Cu mineralization at Mandamah (NSW) and MVT style Pb-Zn mineralization at Pitchi (Iran). At Mandamah, mineralisation is buried under 30 m of residual regolith and a further 50 m of re-weathered alluvium. Mineralised zones that intersect the base of weathering are characterized by low EM and EC in the upper 6 m of the transported regolith profile. This can be related to changes in clay mineralogy and the destruction of carbonates caused by an acid chimney that formed during a “prograde” phase of regolith development. These patterns are also variably reflected in soil pH and the distribution of selectively-extracted Ca, Mg, S, Ba and REE in the upper part of the transported regolith profile, but generally not in the elements of economic interest (Au, Cu or Mo). At Pitch carbonate-hosted Pb-Zn mineralisation is covered by 80 m of barren dolomitic sedimentary rocks and a thin layer of alluvium and colluvium. There is an increase in the EM and EC as well as Na and S in the transported regolith above mineralisation and adjacent low EC values, but again no detectable patterns in the main ore-related metals. The combined geochemical and (EM) geophysical approach provides a new approach to exploration in areas with economically prospective geology but where mineralization is buried by various forms of cover including transported regolith.

Influence of environmental variables on the diatom communities of oligotrophic reservoirs for public water supply (Guarulhos, Southeast Brazil)

Abstract Aim: Our study aimed at analyzing the diatom community structure of the plankton, periphyton, and surface sediments, and their relationship with the environmental variables of two reservoirs, Tanque Grande and Cabuçu, located in the city of Guarulhos, Metropolitan Region of São Paulo. Methods Three sampling stations were stablished in each reservoir. Samples of water and periphyton were collected during the dry (August 2013) and the rainy periods (January 2014), while the sediment was sampled only during the dry period. Water abiotic limnological variables were determined and quantitative and qualitative analyses were performed after the oxidation of diatom samples. Results Both reservoirs presented low values of electrical conductivity, pH and nutrients. The diatom community was represented by 30 taxa distributed in 20 genera. The diatom diversity was higher in the plankton, with three exclusive species. All taxa collected from the surface sediments also occurred in the plankton. The periphyton was represented by six taxa that were exclusive to this habitat. Conclusion Our results indicated that the environmental variables were responsible for the limnological changes in the two reservoirs. In the studied reservoirs, the species composition of diatoms differed slightly between the plankton and the surface sediments, while we found a different community in the periphyton, with the presence of exclusive species. The two climatic periods showed differences in the abundance of species, but no considerable differences in the species composition between the two reservoirs were observed.

The allelopathic effects of Amaranthus on seed germination, growth and development of vegetables

ABSTRACTAmaranthus is a versatile plant used as a food, but it is also a recognised weed due to its competitive ability. Amaranthus is very nutritious and preferred by rural communities as a leafy vegetable, but it also contains anti-nutritional components and there are reports of allelopathic activity. This study investigated the effects of Amaranthus on seed germination, and the effects of Amaranthus grown in pots and in the field on follow-up crops planted in the same soil. Extracts of the whole plant, stems, leaves, flowers and roots of Amaranthus exhibited severe inhibition of seed germination of vegetables, as well as of weed seeds of Conyza bonariensis. Significant allelopathic effects were observed on tomato seedlings in the pot experiment with reduced growth in two of the treatments. However, no significant effects were observed in any of the field trials. All of the Amaranthus extracts exhibited very high electrical conductivity (EC) value. In a dilution experiment, the diluted extracts exhibited lower EC values, with no or limited seed germination at concentrations higher than 3.12 mg ml−1 and corresponding EC value of 2.1 mS cm−1. The high EC values that were associated with the allelopathic effect, possibly resulted from allelochemicals in the plant, but these were not identified in this study. The origin and persistence of the allelopathic effect warrant further research to determine the risks for agricultural crops.

QUALITY OF NATURAL COFFEE DRIED UNDER DIFFERENT TEMPERATURES AND DRYING RATES

The final quality of coffees depends on the preservation of the cell membranes of the coffee beans, which can be damaged during the drying. Thus, the aim of this study was to assess the immediate and latent effects of the air temperature and drying rate on the sensorial quality of natural coffees, as well as its relationship with the chemical e physiological characteristics of the coffee beans. Mature fruits of arabica coffee were harvested and sundried to moisture content of approximately 35% (wb) and then moved into a mechanical drier under different conditions of drying. This process involved the combination of three dry bulb temperatures – DBT (35°C, 40°C, and 45°C) and two dew point temperatures – DPT (2.6°C and 16.2°C). Thus, the relative humidity of the air used for drying was a dependent variable of DTB and DPT, and as consequences, different drying rates were achieved for each DBT. The increase in the drying rate for the temperatures 35°C and 40°C has a negative effect on the final quality of natural coffee beans. However, for the temperature of 45°C, the effects of the drying rate on the coffee beans are overlaid by the thermal damages that are caused at this level of heating. Higher sensory scores for coffee are linked to lower values of electrical conductivity and potassium leaching of the exudate of the coffee beans, as well as lower values of fatty acids. It is emphasized that while the temperature of 35o C is recommended for the production of specialty coffees the temperature of 45o C is not.

Caracterização hidroquímica e isotópica dos aquíferos fissurais da região de Itabuna/BA

Os aquíferos cristalinos representam importantes reservas de águas em termos mundiais e são caracterizados pela complexidade que governam o movimento e o armazenamento da água em suas descontinuidades geológicas. Igualmente complexos são os mecanismos atuantes na interação rocha/água. O entendimento dos processos físicos e geoquímicos atuantes nestes aquíferos é crucial para sua gestão. Este trabalho apresenta uma caracterização hidroquímica preliminar das águas do aquífero fissural na região de Itabuna/BA, a partir da identificação dos tipos hidroquímicos dominantes. As análises químicas indicam elevada variabilidade da composição química da água, que pode estar associado à ocorrência de vários processos distintos, incluindo a interação com a água marinha e diferentes graus de interação com as rochas que hospedam a água em suas descontinuidades geológicas. As amostras de águas subterrâneas foram reunidas em dois grupos distintos: o primeiro grupo é representado por água do tipo cloretado sódico e menores valores de condutividade elétrica, associados às amostras coletadas nas porções mais rasas de sub-superfície; o segundo grupo é representado por tipos hidroquímicos bicarbonato sódico, cálcico ou cálcio-magnesianos, provavelmente associadas às águas com elevado grau de interação com as rochas do aquífero, proveniente de recarga pretérita. Os resultados de análise isotópica da água subterrânea e meteórica sugerem a existência de um leve excesso de deutério, decorrente de condições climatológicas locais.

Effects of an Aluminum Sulfate and Ferric Chloride Blend on Poultry Litter Characteristics in Vitro

Previous studies have applied various concentrations of aluminum sulfate and ferric chloride separately to poultry litter to reduce environmental pollution and increase chicken productivity. In the present study, we investigated the effect of using a blend of these 2 chemicals under 5 different treatments: control (no addition), 50 + 50, 25 + 50, 50 + 25, and 25 + 25 g/kg of litter, which consisted of fresh chicken manure (1 kg) and sawdust (4 kg) thoroughly mixed in a 70 × 47 × 43 cm box. NH3 and CO2 volatilizations, pH, electrical conductivity (EC) and moisture content of the poultry litter were assessed weekly up to 6 wk and in the case of total and water-soluble nutrients they were assessed after 1 and 42 d. The control treatment had higher NH3 and CO2 volatilizations than the treated litter throughout the experiment. EC and pH showed an inverse relationship, whereby the control treatment had high pH and low EC values and the treated litter had low pH and high EC values. After 42 d, nitrogen levels were significantly reduced in the control treatment, whereas the 50 + 50 g/kg treatment had the highest content. Conversely, water-soluble phosphorus levels were much lower in the treated poultry litter after 1 and 42 d. A higher ferric chloride concentration (25 + 50 g/kg) in the blend was more effective than a higher aluminum sulfate concentration (50 + 25 g/kg). These findings demonstrate that a combination of aluminum sulfate and ferric chloride may be a useful amendment for reducing NH3 and CO2 volatilizations, pH, and moisture content of poultry litter, which will help in improving poultry productivity, pollution control, and poultry litter fertilizer usage.

Effect of Seed Priming on Biochemical Changes in Fresh and Aged Seeds of Cucumber

The present investigation was conducted at the laboratory of Seed Science and Technology, Indian Institute of Horticultural Research, Hessaraghatta, and Bangalore, India during March 2014 to September 2014. The objective of the study was to identify effect of seed priming on biochemical changes in cucumber seeds. This study showed that the enhancement in seed viability and vigor in primed seeds was due to low membrane injury coupled with high enzyme activities (dehydrogenase and amylase). The priming with KH2PO4 and K2HPO4 reduced the electrical conductivity (EC) significantly in seed. With seed priming with KH2PO4 10-3M there was 44 and 45% lower EC values compared to unprimed. This priming with KH2PO4 10-3M and K2HPO410-3M reduced seed leachate values indicating priming initiates the process of repair by stabilizing membrane integrity. priming significantly increased dehydrogenase enzyme in low vigor seeds was noticed. These changes are to the tune of 16 and 21 per cent due to priming with K2HPO410-3M and KH2PO410-3M, respectively in cucumber. Similarly, higher amylase activity was noticed upon priming in low vigor seeds These are to the extent of 2.1, 1.94 folds higher due to priming with K2HPO410-3M and KH2PO410-3M, respectively, in cucumber and 1.4 & 1.4 folds higher due to priming with K2HPO410-3M .Alteration in protein profiles in low vigor seeds compared to high vigor seeds was noticed in the crops. The disappearance of some low molecular weight proteins in low vigor seeds might be the reason for lesser performance of these seeds. Seed priming although not restored all the lost proteins, but induced synthesis of some other proteins which probably might helped in restoration of germination ability and vigor. Esterase Isozyme profiles also showed variation in their number and intensity in less vigor seeds. Primed seeds further exhibited tolerance to abiotic stress condition (high temperature and water stress) as evident from higher germination compared to unprimed. Besides these studies, some advanced studies were initiated in the present investigation to identify changes in proteome profiles and isocitratelyase gene expression in high vigor and low vigor seeds during germination.

Groundwater isotopic variations in a uranium mining site: subsidies for contamination studies

The Caetite Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, faces not only the challenges associated with water scarcity but also the potential contamination processes due to mining activity. The only active uranium production center in Brazil (URA) is located in this watershed and the sustainability of mining and milling operations, as well as the survival of the local community, is highly dependent on the availability of groundwater resources . This paper analyzes the stable isotopes variation of Deuterium ( 2 H) and Oxygen-18 ( 18 O) in CEB’s groundwater to investigate its dynamics and mixing of water sources as part of initial efforts to characterize the hydrogeology of this area for future contamination and recharge studies. Measurements of δ 2 H, δ 18 O, total dissolved solids (TDS), pH, and electrical conductivity (EC) were carried out in water samples from 28 wells. A total of 102 groundwater samples were analyzed during the dry and wet seasons from 2012 to 2014. All the groundwater samples plotted below the local meteoric line toward more enriched δ18O values, an indicative of evaporation process . 2 H and 18 O data suggests that the main source of groundwater recharge is local precipitation and there is no mixing of infiltrating rainwater with older groundwater. These results provide evidence that the aquifer system in the CEB has a relatively fast turnover time, which contribute to the vulnerability of the aquifer to contamination. These findings are corroborated by the low TDS and EC values indicative of short time in water-rock interaction .

Field assessment of surface runoff, sediment yield and soil erosion in the opencast mines in Chirimiri area, Chhattisgarh, India

Chirimiri Coal field is located in the Koriya district of Chhattisgarh state of India. It lies in the valley of the Hasdeo River and is spread over 125 km2 area. Ever increasing problem of declining forest resources and water quality is a cause of concern particularly due to excessive soil erosion resulting in soil sediment deposition from the overburdened dump. Dwindling resources has compelled the policy makers to search for alternatives such as waste lands and mined areas to improve soil and water resources for use in agriculture and allied sectors while maintaining the local ecology and hydrology. Most Opencast mines release huge amount of mining wastes in the form of overburden dump (OBD) materials that are prone to soil erosion and also create problems of sedimentation and deteriorating water quality, affecting agriculture. Historical daily rainfall data for 21 years and daily surface runoff as estimated by SCS-Curve Number method were analysed. Sediment yield was estimated at lower end of erosion face of OBD and near drainage outlet of opencast mine. Assessment of soil erosion from OBD materials was made byRevised Universal Soil Loss Equation (RUSLE) method and was compared with direct field measurements by placing plastic sheets in downstream portion of OBD. As a result monsoon rainfall constitutes 91.6 percent of the annual rainfall and surface runoff constitutes 31.7 percent of monsoon rainfall. The surface runoff was found to be 4133 m3/ha while the sediment yield of drainage effluent was negligible. The soil loss from OBD as estimated by the RUSLE method (62.7 t ha−1 yr−1) was quite close (+13.2 percent) to the direct field measurement 54.44 t ha−1. The sediment samples from OBD were found acidic in nature and exhibited low values of Electrical Conductivity (EC), Organic Content (OC), Water Holding Capacities (WHC), and Available Nitrogen (N), Phosphorus (P) and Potassium (K). For controlling soil erosion of OBD, mechanical and vegetative measures have been suggested along with installation of sediment traps inside and outside the mines. There is good scope to backfill the mines with the OBD in the form of well laid out terraces to support plantation. This can be eventually used for leguminous fodder/grass production.