267,082 research outputs found
Effect of soil applied zinc sulphate on wheat (Triticum aestivum L.) grown on a calcareous soil in Pakistan
A field experiment was conducted to investigate the effect of soil application of zinc fertilizer on yield and yield components of wheat (Triticum aestivum L. cv. Inqlab 91) grown on calcareous soil in Pakistan. The levels of zinc sulphate were 0 (control), 5, 10, 15, 20, 25 and 30 kg ha-2 and the zinc sulphate was combine-drilled at the time of sowing. Zinc sulphate increased the Leaf Area Index, the total number of fertile tillers m -2, number of spikelets spike-2, spike length, grain spike-2, thousand grain weight, grain yield, straw yield and biological yield and decreased harvest index. Most of the response trends were curvilinear although the decrease in harvest index was linear. All applications of zinc sulphate gave economic increases in margins over costs but the application of 5 kg ha-2 gave the highest marginal rate of return. It is recommended that under such calcareous soil conditions growers can expect good returns from the application of 5 kg zinc sulphate ha-2 at the time of sowing but if the grain price were to increase or the price of zinc sulphate were reduced economic responses could be expected from higher levels of zinc sulphate. © 2008 Akadémiai Kiadó
Magnesium sulphate in the treatment of acute asthma: evaluation of current practice in adult emergency departments
Background: A recent meta-analysis showed that intravenous and nebulised magnesium sulphate have similar levels of evidence to support their use in the treatment of acute asthma in adults. This consisted of weak evidence of effect on respiratory function and hospital admissions, with wide confidence intervals ranging from no effect to significant positive effects. Current BTS/SIGN guidelines suggest an equivocal role for intravenous magnesium sulphate and no role for nebulised magnesium sulphate. A study was performed to assess what emergency physicians currently do in their management of acute asthma.
Method: A postal survey was undertaken of all adult emergency departments within the UK. A structured question naire was sent to all clinical leads in emergency medicine about their current usage of both intravenous and nebulised magnesium sulphate in the treatment of acute asthma.
Results: 180 of the 251 emergency departments in the UK responded (72%). Magnesium sulphate was used in 93%, mostly because it was expected to relieve breathlessness (70%) or reduce HDU/ITU admissions (51%). It was predominantly given to those patients with acute severe asthma (84%) and life-threatening exacerbations (87%), with most stating they would give the drug if there was no response to repeated nebulisers (68%). In comparison, nebulised magnesium sulphate was only used in two emergency departments (1%). The main reason for not administering the drug via a nebuliser was insufficient evidence (51%).
Conclusions: Intravenous magnesium sulphate is widely used for acute asthma, usually for patients with severe or life-threatening asthma who have not responded to initial treatment. Nebulised magnesium sulphate, by contrast, is hardly used at all. The use of intravenous magnesium sulphate is more extensive than current guidelines or available evidence would appear to support
Assessment of Chemical Inhibitor Addition to Improve the Gas Production from Biowaste
The coexistence of sulphate-reducing bacteria and methanogenic archaea in the reactors during the anaerobic digestion from sulphate-containing waste could favor the accumulation of sulfide on the biogas, and therefore reduce its quality. In this study, the effect of sulphate-reducing bacteria inhibitor (MoOâ2
4 ) addition in a two phase system from sulphate-containing municipal solid waste to improve the quality of the biogas has been investigated. The results showed that although SRB and sulphide production decreased, the use of inhibitor was not effective to improve the anaerobic digestion in a two phase
system from sulphate-containing waste, since a significant decrease on biogas and organic matter removal were observed. Before MoOâ2 4 addition the average values of volatile solid were around 12 g/kg, after 5 days of inhibitor use, those values did exceed to 28 g/kg. Molybdate caused acidification in the reactor and it was according to decrease in the pH values. In relation to microbial consortia, the effect of inhibitor was a decrease in Bacteria (44%; 60% in sulphate-reducing bacteria) and Archaea (38%) population
Constraints on climate forcing by sulphate aerosols from seasonal changes in Earth's spin
Angular momentum exchanges between atmosphere and solid Earth are strongly modulated
by variations in global atmospheric circulation. Geodetically determined length-of-day (LOD)
fluctuations provide an independent resource to investigate climate changes. Here, I evaluate
the effects of volcanic and anthropogenic sulphate aerosols on Earthâs rotational energy variations.
The period analysed, 1980â2002, shows that the strongest seasonal LOD variations are
related to sulphate peak concentrations from the El-Chichon 1982, and Pinatubo and Cerro ÂŽ
Hudson 1991 volcanic eruptions. The Earthâs rotational energy budget implies that radiative
forcing alone cannot produce the observed LOD anomalies. Rather, the required amount of
atmospheric kinetic energy can be explained only by a strong influence of sulphate aerosols
on energy partitioning into the atmosphere, for example, as sulphate aerosols affect latent heat
release and transport during condensationâevaporationâfreezing cycles. Overall, the effects of
sulphate aerosols on Earthâs spin changes are faster than those produced by greenhouse gases
Contact allergy and sociodemographic characteristics
The aim of the study was to determine the frequency of positive patch test reaction to different contact allergens according to patients age, sex, occupation and clinical features. Between 1999 and 2003, patch testing was performed in 3,293 patients with respective clinical diagnoses. Patch testing was done by the standard technique proposed by the International Contact Dermatitis Research Group (ICDRG). Study results showed statistically significant differences in patch test response according to sex and age for three allergens (cobalt chloride, nickel sulphate and thiomersal); according to occupation for nine allergens (cobalt chloride, nickel sulphate, balsam of Peru, fragrance mix, thiuram mix, wood tars, neomycin sulphate, thiomersal and detergents), and clinical diagnosis for two allergens (nickel sulphate, and wood tars). The most common and relevant allergens were: nickel sulphate, cobalt chloride and carba mix. They were found in all examinees regardless of age, s! ex, occupation and diagnoses. The increased awareness of allergens and their potential sources may help to limit the usage of these chemicals in manufacture of consumer products
Modelling the corrosion behaviour of Al2CuMg coarse particles in copper-rich aluminium alloys
The corrosion behaviour of 2024 aluminium alloy in sulphate solutions was studied; attention was focused on the influence of coarse intermetallic Al2CuMg particles on the corrosion resistance of the alloy. Model alloys representative of the aluminium matrix and of Al2CuMg coarse intermetallics were synthesized by magnetron sputtering. Open-circuit potential measurements, currentâpotential curve plotting and galvanic coupling tests were performed in sulphate solutions with or without chlorides. Further explanations were deduced from the study of the passive films grown on model alloys in sulphate solutions. The results showed that model alloys are a powerful tool to study the corrosion behaviour of aluminium alloys
Rates of carbonate cementation associated with sulphate reduction in DSDP/ODP sediments: implications for the formation of concretions
DSDP/ODP porewater profiles in organic carbon-bearing (<5% org. C) sediments commonly show decreases in Ca2+ concentrations and increases in alkalinity over depths where sulphate is being removed by microbial reduction. These Ca2+ depletion profiles represent the combined effect of diffusion, advection and reaction (addition by ion exchange and removal by precipitation mainly as CaCO3 and/or dolomite). A diagenetic model has been used to estimate the rate constant (k) for Ca2+ removal by precipitation during sulphate depletion over depths of 15-150 m, assuming first order kinetics. The rate constants for Ca2+ removal range from 10(-14) to 10(-11) s(-1) in 19 DSDP/ODP sediments, which span a range of bottom water temperatures (0-10 degreesC), lithologies (calcareous to clastic) and sedimentation rates (0.001-0.4 cm year(-1)). Values of k correlate with sedimentation rate (omega) such that log k=1.16 log omega-10.3, indicating that faster rates of Ca2+ removal occur at higher sedimentation rates where there are also higher degrees of saturation with respect to CaCO3 and dolomite. Depth-integrated masses of Ca2+ removed (<100 mumol cm(-2)) during sulphate depletion over these depth ranges are equivalent to a dispersed phase of approximately 1.5 wt.% CaCO3 or 3 wt.% dolomite in a compacted sediment. The complete occlusion of sediment porosity observed in concretions with isotopic signatures suggesting carbonate sourced from sulphate reduction therefore requires more time (a depositional hiatus), more rapid sulphate reduction (possibly by anaerobic methane oxidation) and/or the continued transport of isotopically light carbonate to the concretion site after sulphate reduction has ceased
Should Magnesium Sulphate Prophylaxis be Used in all Cases of Severe Preeclampsia?
A case control study, undertaken in the department of Obstetrics and Gynecology in a tertiary referral centre, was designed to administer standard dose of magnesium sulphate to 50 randomly selected severely preeclamptic women in labor (Group 1). 48 women who formed the control group did not receive the drug (Group 2). The admission â delivery interval, rate of Cesarean section showed no statistically significant difference. Four patients developed convulsions in Group 1 in contrast to twelve patients in Group 2. Efficacy of magnesium sulphate at preventing eclampsia was calculated as 68%. Mild respiratory depression occurred in two cases and oliguria in eight cases in Group 1. Both the conditions improved on suspending further doses of magnesium sulphate. No patient had post partum haemorrhage in Group 1 although 4% patients had it in Group 2. Neonatal outcome was comparable in both the groups. Hence magnesium sulphate may be regarded as a fairly safe and effective prophylactic agent for eclampsia when used in severe preeclampsia in labo
Mitigation of corrosion attack on carbon steel coated cermet alloy in different anion contents
This research study evaluated the corrosion mechanism attack on carbon steel coated with cermet alloys (WC9% Ni) in seawater at different sulphate-to-chloride ratios. The four different sulphate-to-chloride ratios were synthesised with the same seawater salinity of 3.5 % and same pH of real seawater. The corrosion tests involved immersion and electrochemical tests. The immersion test is used to determine the cermet coating ability to withstand the corrosion attack based on different ratios of anions present in the seawater at different periods of immersion. The corrosion attack was characterized by optical and Scanning Electron Microscopy (SEM). The aggressive anions present in the seawater influenced the corrosion attack on the cermet coating. For immersion test, results revealed that increasing sulphate more than chloride, increased the weight loss of cermets. The electrochemistry analysis showed that the passive layer forms on cermet coating prevented the material from further corrosion attack. However, due to its porosity, the passive layer collapsed and exposed the material for other corrosion reaction. For electrochemical test, the result shows that the solution with sulphate-to-chloride ratio of 0.14 (real seawater) has the highest corrosion current and Open Circuit Potential (OCP) compared to other solutions (different sulphate-to-chloride ratio). In conclusion, sulfate and chloride show their competition to attack the cermet coating on carbon steel and the higher the amount of chloride present in seawater, the higher the corrosion rate and pits formed on the cermet coating
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