Maximum Residue Research Articles

Electrocoagulation treatment of debrominated wastewater: A critical observation and analysis

Present study deals with the treatment of highly polluted dibrominated wastewater (DWW) using electrocoagulation process. The study methodology utilized 2 L batch reactor with four parallel aluminum (Al) electrodes with varying electrode gaps, current density and pH. The results show optimum value of 1.5 cm for electrode gap, 50 Amp/m2 forcurrent density and pH 9. For these optimal valus, the removal efficiencies emerged as: 34.09 % for COD, 29.80 % for TDS, 56.17 % for color and 20 % for turbidity. At pH 9, the maximum total metal loss (TML) was 1.77 g/L, while the highest power consumption was 2.4 Wh/L at pH 3. While pH 3 exhibited the most efficient settling rate, pH 9 resulted in maximum residue and foam weight of 8.42 g/L. Further, electrodes and residue were characterized using SEM, EDX, XRD and FTIR techniques. Investigation given detail information about applicapability of EC process to treat DWW. Results demonstrated that EC process is well applicable to treat DWW.

Simulating soil-carbon-water interactions in two profiles to select precision cover for soil-health and drought-resilience

BackgroundThe disseminated information to the stakeholders is mostly regional as the urge to meet global production goals and adoption of intensive agricultural practice have been amplified. Regional management strategies (MS) are mainly based on a broad-spectrum of ecoregions and climate scenarios and thus, are not always successful to prescribe a cover without failure. This produces a dilemma which restrains the farmers from adapting soil-covers as a climate-smart conservation practice. Simulating agroecosystems for better-understanding of soil-plant-water relationships within a soil profile would improve the societal acceptance of using cover crops. We intended to bring light into the uncertain conditions of production during drought and inconsistencies in soil organic carbon (SOC) sequestration through analyzing the impacts of soil cover, residue decomposition and inherent soil characteristics on soil moisture variability. MethodIn-situ effects of cover, residues and manure application on specific soil-layers were considered to simulate above and belowground biomass contents and impacts of applied residues, C, nitrogen and moisture content of soils at different crop-growth phases. Soil-environmental factors of seven MS were modeled to reveal the subtle conditions within the profiles of two similar soils of closely-located sites. Decision support systems with Strategic Analysis along with the simulated-results were used for long-term impact-analysis and select a precision cover based on soil and site. Moisture movement through whole soil profiles during drought was analyzed to understand the scope of improving the resiliency of the forage systems. We also compared the impacts of fallow, manure application along with the residue incorporation from rye, clover and winter wheat on two loamy fine-sand soils with similar reaction but contrasting permeability and clay +silt contents. ResultsIrrespective of soil types, impacts of management strategies on SOC were found statistically significant for both 0–20 cm and 20–40 cm soil layers. Slight differences in clay+silt fractionation resulted in different SOC in soil layers and ultimately the moisture availability status. Due to complex interaction effects of management-strategies and soil properties, N leaching was different within two soil profiles. N-uptake was found definable by SOC up to 96% in residue-only treatments and 83% in manure-based MS. ConclusionsA cover of winter-wheat with 50–50 manure +fertilizer and residue application could prove as the best management strategy to improve soil-health and long-term productivity. A precision-cover of clover which results in maximum residue, surface residual-C and SOC addition, and minimum N-leaching could be recommended for resource-use efficiency on low-fertile acid loamy sand soils during drought.

Metabolism and residue differences of Enrofloxacin between the brain and peripheral tissues and the resulting brain damages in crucian carp (Carassius auratus var. Pengze).

This study aimed to explore the metabolism and residue differences of Enrofloxacin (ENR) at two doses between the brain and peripheral tissues (liver, kidney, and muscle) along with the brain damages caused by ENR in crucian carp (Carassius auratus var. Pengze). The concentrations of ENR in tissues were determined using a validated high-performance liquid chromatography (HPLC) analysis. Relying on the hematoxylin-eosin (HE) staining method, brain damages caused by the drug were evaluated by the section of pathological tissue. Metabolism and residue results showed that ENR could be detected in the brain throughout the experiment both at median lethal dose (LD50 at 96 h, 1949.84 mg/kg) and safe dose (SD, 194.98 mg/kg), as well as in the three peripheral tissues. The maximum residue at LD50 followed the decreasing order of liver >kidney > brain > muscle. Although the Cmax of ENR at SD in the brain was significantly lower than that in other peripheral tissues (p < .05), it still reached 41.91 μg/g. The T1/2 of ENR in brain tissue at the same dose was both shorter than that in peripheral tissues. At LD50 , the amount of ENR residues in brain was lower than that in peripheral tissues on the whole, except that it had been higher than in the muscle for the first 3h. At SD, the drug residue in brain tissue was lower than that in peripheral tissues from 12 h to 960 h, but it exceeded the muscle and kidney at 1h and 6h, respectively. At 960 h, the residual amount of ENR at SD in the brain was 0.09 μg/g, while it was up to 0.15 μg/g following the oral administration at LD50 . Demonstrated by the HE staining, there were pathological lesions caused by ENR in the brain at LD50 , which were characterized by sparse neural network and increased staining of glial cells. The present results indicated that metabolism and residue of ENR in crucian carp were affected by the tissue type and drug dosage, and the ENR could also bring about histopathological changes in the brain.

Short-Term Field Evaluation of Low-Cost Sensors Operated by the “AirSensEUR” Platform

Electrochemical low-cost sensors, suitable for the monitoring of different air quality parameters such as carbon monoxide or nitrogen dioxide levels, are viable tools for creating affordable handheld devices for short-term or dense air quality monitoring networks for long-term measurements and IoT applications. However, most devices that utilize such sensors are based on proprietary hardware and software and, therefore, do not offer users the ability to replace sensors or interact with the hardware, software, and data in a meaningful way. Initiatives that focus on an open framework for air quality monitoring, such as the AirSensEUR project, offer competitive open source alternatives. In this study, we examined the feasibility of the application of such devices. Five AirSensEUR units equipped with chemical sensors were placed next to a reference air quality measuring station in Vienna, Austria. During co-location, concentrations of 0.20 ± 0.06 ppm, 7.14 ± 8.66 ppb, and 17.58 ± 9.90 ppb were measured for CO, NO, and NO2, respectively. The process of evaluating the performance of the low-cost sensors was carried out and compared to similar studies. Data analysis was carried out with the help of the basic functions in MS Excel. We investigated the linear correlation between the sensor and reference data and thus calculated the coefficient of determination, the average and maximum residuals, and the correlation coefficient. Furthermore, we discuss sensor properties in regard to selectivity and long-term stability.

Assessing spatial interpolation based on sampling size and point geometry in elevation mapping applications

&#x0D; &#x0D; &#x0D; &#x0D; In order to produce a correct elevation map, it is necessary to use not only the accurate technology for data acquisition, but also to utilize an appropriate method of interpolation, which will reflect the topographic features in a reliable manner. The first key element in elevation map production is the proper geometrical distribution of measurement points. The second key component is the density of measurement points, which indicates the distance between pairs in the dataset. In this study, two different types of sampling design were taken into account, random and systematic sampling, to create the elevation map. In random sampling, 33 points were used with the distance in the range of 15–30 km. In systematic sampling, a total of 100 points were utilized located at the distance of 5 km apart. Then, two distinct methods of interpolation were applied to produce a map: deterministic (Inverse Distance Weighting) and geostatistical (Ordinary Kriging with application of the Gaussian, Exponential, and Spherical fitting separately). These methods were compared using a statistical approach to validate the predictive abilities of the chosen interpolation methods. As the results showed, the geostatistical method, namely, Ordinary Kriging with Exponential fitting, revealed better performance compared to the deterministic. It was seen that the overall performance of the interpolated map varies with the number of points in the dataset and strongly relates to the sampling design. In the case of systematic sampling, the accuracy of the map was found to be much better compared to the results of random sampling. It was also proposed to use the error maps in order to identify areas with the maximum residuals. It became apparent that in the case of random sampling, the greatest errors were mostly concentrated in the areas where distances between the measured points were fairly large. By contrast, in the case of systematic sampling, the largest residuals were found in areas with complex topological patterns, especially in the regions with a steep slope gradient. Choosing the appropriate method of interpolation with the minimum error is of great importance in geostatistical operations and topographic engineering. Thus, the current manuscript may serve as a guideline in making the right decision concerning the interpolation method in elevation mapping applications of 1:2000000–1:1000000 scales.&#x0D; &#x0D; &#x0D; &#x0D;

Rapid and simultaneous determination of glyphosate, glufosinate, and their metabolites in soil by high performance liquid chromatography-tandem mass spectrometry

建立了快速同时测定土壤中草甘膦(GLY)、草铵膦(GLUF)及其代谢物的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。分别对前处理和色谱-质谱条件进行优化,样品采用0.5 mol/L氨水作为溶剂振荡提取,离心,上清液过滤膜后,直接采用HPLC-MS/MS测定,电喷雾离子源(ESI-),多反应监测(MRM)模式下检测,外标法定量。结果表明,采用Dikma Polyamino HILIC色谱柱(150 mm×2.0 mm, 5 μm)进行分离,目标化合物峰形良好,响应值高。GLY及其代谢物氨甲基膦酸(AMPA)在5.0~500 μg/L范围内线性关系良好;GLUF及其代谢物N-乙酰基-草铵膦(NAG)、3-(甲基膦基)丙酸(MPP)在2.0~500 μg/L范围内线性关系良好;5种化合物的相关系数(r2)均大于0.998,可以满足定量分析的要求。GLY、GLUF及其代谢物的方法检出限(LOD)在2.0~4.0 μg/kg之间,方法定量限(LOQ)在6.7~13.3 μg/kg之间。在空白土壤样品中添加0.02、0.05、0.2 mg/kg 3个水平的5种化合物混合标准溶液考察回收率,结果表明,低有机质含量土壤中5种化合物的平均加标回收率在74.2%~101%之间,相对标准偏差(RSD)在0.93%~6.8%之间;高有机质含量土壤中5种化合物的平均加标回收率在90.8%~116%之间,RSD在0.40%~7.1%之间。采用建立的方法对实际土壤样品进行测定,AMPA、GLY、MPP、GLUF、NAG的检出率分别为45%、25%、10%、5%和5%,最大残留量分别为147、35.2、154、21.6和11.0 μg/kg,说明土壤中GLY、GLUF及其代谢物残留需要引起一定的关注。该方法简化了前处理步骤,具有简单、快速、绿色环保、成本低、准确度和灵敏度高、重现性好等优点,适用于大批量不同有机质含量土壤样品的检测,为研究其在土壤中的残留状况和环境行为提供了可靠的技术支持。

Determination of Tetracycline Residues in Kidney and Muscle of Beef Cattle Slaughtered in Dire Dawa and Harar Municipal Abattoirs, Eastern Ethiopia.

Background:Antibiotics are among the most widely used drugs in farm animals for therapeutic and prophylactic purposes. However, the antibiotic residues in meat are a serious public health concern due to their harmful effects on consumer health. Besides this problem, there is limited information on the level of the antibiotic residues, including tetracycline residues. Therefore, this study was aimed to determine the tetracycline residues in the kidney and muscle samples of beef cattle in Harar town and Dire Dawa city.Methods:A study was conducted on 500 randomly selected carcass (250 kidney and 250 muscle samples) slaughtered at Dire Dawa and Harar municipal slaughterhouses between December 2018 and December 2019. The samples were collected aseptically and screened for tetracycline residues by thin layer chromatography. Then, presumptive positive samples were analyzed using high-performance liquid chromatography to get a quantitative outcome. Descriptive statistics were used to determine the frequency, mean, or standard deviation to determine the summary values and distribution of the outcomes. Finally, the data was analyzed using SPSS version 21 software.Results:Out of 500 samples, oxytetracycline residues were detected in 84% of the samples. However, tetracycline and doxycycline were not detected in all samples. Among the kidney and muscle samples collected from Dire Dawa and Harar abattoirs, 109 (87.2%) and 101 (80.8%) were positive for oxytetracycline, respectively. Oxytetracycline residue levels in Dire Dawa ranged from 57 to 607 µg/kg for the kidney and 10.14 to 435 µg/kg for muscle samples. Among the samples collected from Harar, the concentration of oxytetracycline residues ranged from 16 to 433 µg/kg and 6 to 435 µg/kg for kidney and muscle samples, respectively, at Harar slaughterhouses. About 22.0% of muscle samples collected from Dire Dawa and 17.8% from Harar town had oxytetracycline residues above maximum residue limits.Conclusions:In general, the study revealed that oxytetracycline residues were prevalent among tetracycline residues analyzed from kidney and muscle samples in the study areas. Thus, there is a risk of consumer exposure to these antibiotic residues that may have human health effects. Therefore, awareness creation and strict regulation is needed by the regulatory authorities for the use of antimicrobial drugs in the livestock industry.

The Optimization of Canola Crop Production through Wheat Residue Management within a Western Canadian Context—A Case Study of Saint-Front, Saskatchewan

In this study, the processes of wheat residue degradation in combination with various tillage treatments were explored to determine the ideal management prescription for maximizing canola crop production. A field experiment within a western Canadian context (near Saint-Front, Saskatchewan), consisting of a 2 × 3 factorial design, was conducted to determine the fate of crop residue under different harvest and treatment scenarios. ATR-Fourier transform infrared (FTIR) spectroscopy, FTIR spectromicroscopy, and synchrotron-based X-ray fluorescence imaging (SR-XFI) were used to explore wheat residue degradation mechanisms. The results indicated maximum canola yields and residue degradation occurred in combination with a combine outfitted with an aftermarket chopper and post-harvest treatment by harrow. Crop residue degradation was attributed to cellulose/linen hydrolysis and supramolecular structure changes from high crystalline to amorphous cellulose. Multi-element loss usually accompanied crop residue degradation. An important aspect of this study is the adoption of field-scale analysis to accurately portray real-world sustainable management techniques within a western Canadian context. The findings provided an optimal combination of crop residue treatment and tillage treatment to increase canola production, which had the potential ability to be applied in other countries. It is also an initial attempt to develop a technical composite of FTIR spectromicroscopy and SR-XFI for examining the mechanism of residue decomposition.

Impact of the insecticide 14C-chlorfenvinphos in a terrestrial ecosystem

Pesticides are an essential component of agricultural production. The increased use of pesticides greatly aided agricultural production, reduced stored grain losses, and improved human well-being in general. However, the use of pesticides may lead to unwanted residues such as traces of pollutants from food, the environment and living tissues. The environmental fate of 14C- chlorfenvinphos was studied using an agricultural ecosystem that included soil, plants, beetles, earthworms and one type of common bird in Egypt (Asfour Baladi). This study was conducted on a restricted field area that was cultivated with maize plants as target crop and soybean plants as an alternate crop. The residue level in soybean seeds was almost 6 times higher than in dry maize seeds. The high concentration of 14C- residues in beetles (1.28µg/g) was observed on day 26 after spraying 14C- chlorfenvinphos and decreased thereafter. The earthworms, on the other hand, showed a progressive increase with time and its maximum residue was detected after 75 days (3.25µg/g) .The dead birds showed the highest concentration of residues in the brain, liver and heart as compared with alive birds in the ecosystem. The chromatographic analysis indicated the presence of the parent compound in addition to three degradation products especially in dry seeds and soil.

Estimation of residue of carbendazim in harvested mushroom fruiting bodies form the treated substrate in Pleurotus spp.

An experiment was conducted to assess the amount of residue present in the mushroom fruiting body harvested from the beds treated with formaldehyde and carbendazim against microbial contaminants. Different species of Pleurotus viz ., P. sajor-caju, P. sapidus and a commercial hybrid was used for the experiment. The different concentration levels of formaldehyde and carbendazim was at the rate of 500 ppm formaldehyde + 10 ppm carbendazim, 750 ppm formaldehyde + 20 ppm carbendazim, 1000ppm formaldehyde + 30 ppm carbendazim, 1250 ppm formaldehyde + 40 ppm carbendazim, 1500 ppm formaldehyde + 50 ppm carbendazim, 1750 ppm formaldehyde + 60 ppm carbendazim, 1000 ppm formaldehyde, 40 ppm carbendazim were applied for managing the contaminants. The investigation revealed that the residue of carbendazim present in mushroom fruiting body was least in the concentration at the rate of 40 ppm carbendazim in P. sajor-caju , 60 ppm carbendazim combined with1750 ppm formaldehyde in P. sapidus , 70 ppm carbendazim combined with 2000 ppm formaldehyde and 40ppm carbendazim in commercial hybrid. The maximum residue was found in the concentration at the rate of 30 ppm carbendazim combined with 1000 ppm formaldehyde in P. sajor-caju and P.sapidus and 40 ppm carbendazim combined with 1250 ppm formaldehyde in commercial hybrid.

Development, validation, and application of a multi-method for the determination of mycotoxins, plant growth regulators, tropane alkaloids, and pesticides in cereals by two-dimensional liquid chromatography\xa0tandem mass spectrometry

Mycotoxins and pesticides regularly co-occur in agricultural products worldwide. Thus, humans can be exposed to both toxic contaminants and pesticides simultaneously, and multi-methods assessing the occurrence of various food contaminants and residues in a single method are necessary. A two-dimensional high performance liquid chromatography tandem mass spectrometry method for the analysis of 40 (modified) mycotoxins, two plant growth regulators, two tropane alkaloids, and 334 pesticides in cereals was developed. After an acetonitrile/water/formic acid (79:20:1, v/v/v) multi-analyte extraction procedure, extracts were injected into the two-dimensional setup, and an online clean-up was performed. The method was validated according to Commission Decision (EC) no. 657/2002 and document N° SANTE/12682/2019. Good linearity (R2 > 0.96), recovery data between 70-120%, repeatability and reproducibility values < 20%, and expanded measurement uncertainties < 50% were obtained for a wide range of analytes, including very polar substances like deoxynivalenol-3-glucoside and methamidophos. However, results for fumonisins, zearalenone-14,16-disulfate, acid-labile pesticides, and carbamates were unsatisfying. Limits of quantification meeting maximum (residue) limits were achieved for most analytes. Matrix effects varied highly (−85 to +1574%) and were mainly observed for analytes eluting in the first dimension and early-eluting analytes in the second dimension. The application of the method demonstrated the co-occurrence of different types of cereals with 28 toxins and pesticides. Overall, 86% of the samples showed positive findings with at least one mycotoxin, plant growth regulator, or pesticide.Graphical abstract

\Effect of some Weed Control Practices on Coriander (Coriandrum sativum L.) Productivity and their Associated Weeds

Two field experiments were carried out during 2016/2017 and 2017/2018 winter seasons at Sids Horticultural Research Farm, Egypt, to evaluate the efficacy of eleven weed control treatments on weeds and coriander productivity with monitoring chemically herbicidal residues by HPLCinbothsoil and coriander seeds in randomized complete block design with four replicates. The results show that coriander seed yield losses due to weed competition varied from 56.6-55.5 percent through the course of this study. Hand hoeing thrice, black polyethylene mulch, rice straw mulch and Stomp extra at 1.7 l/feddan treatments gave 8.95-6.90 percent of weed control accompanied with coriander increases seed yield varied from 200.9-230.5 percent than unweeded check. Such increases in seed yield per feddan are positively correlated with various studied yield components and negatively with various studied weed categories emphasizing the need of good weed control program in coriander crop production with less herbicide residues, which determined by HPLC in both soil and seed coriander were below than the maximum residue allowable level expect with Ultra afalon at 1.0 l/fed. in the soil. Economic evaluation, showed that seed yield of coriander is a profitable enterprise for coriander growers by using hand hoeing thrice or Stomp extra or black polyethylene mulch and rice straw mulch treatments which can be recommended as good and clean alternatives for weed control in coriander crop.

Thermal characterization of date palm/epoxy composites with fillers from different parts of the tree

Thermal expansion and viscoelastic properties of the date palm fibre (DPF)/epoxy composites were influenced by the type of filler from different parts of the date palm tree. The variation in properties is mainly due to the difference in fibre composition between the DPF from leaf stalk, leaf sheath, fruit bunch stalk, and tree trunk. Among the investigated composites, composite reinforced with the tree trunk fibre displayed higher thermal stability as visible from the lower weight loss, higher onset and inflection temperatures and maximum residue % from the thermogravimetric analysis (TGA). Lower coefficient of linear thermal expansion (CLTE) obtained from thermomechanical analysis (TMA) further provided supportive evidence for dimensional stability at elevated temperature. Based on the dynamic mechanical analysis (DMA) results, the DPF/epoxy composites with fruit bunch stalk fillers displayed a better property by showing higher storage modulus and lesser tan delta values. Hence, composite from the tree trunk and fruit bunch stalk fibres of date palm is recommended for applications requiring superior thermal resistance.

Homology Modelling and in silico Characterization of Laccase from Lentinula edodes

Introduction: Laccases are phenol oxidases which belong to the superfamily of multicopper oxidases. Laccases are found in almost all wood-rotting fungi. There is evidence that laccases can play an important role in lignin degradation, fruiting body formation, pigment formation during asexual development, competitor interactions and pathogenesis. Laccase from Lentinula edodes is used in variety of applications like to reduce toxicity, partial decolourization of effluent water and decolourization of chemically different dyes like Remazole brilliant blue R, bromophenol blue, methyl red and naphtol blue black. The objectives of this study include prediction of three dimensional (3D) structure of laccase from Lentinula edodes using homology modelling, in silico characterization and analysis of laccase from this organism using computational methods. Methods: The sequence of laccase from Lentinula edodes was retrieved from UniProt database and sequence analysis was carried out using BLAST for the selection of template. The protein 3D structure was modelled using ModWeb server. The obtained 3D model of the laccase from Lentinula edodes was visualized and analyzed using RasMol. The quality of the 3D structure of protein was verified by its energy and stereochemical properties. The erred regions were remodelled by loop modelling using SWISS PDB viewer. Further, the in sillico characterization of the laccase from Lentinula edodes was computed. Results and Discussion: The 3KW7 A of Trametes Sp AH28-2 is used as template for model building of laccase from L. edodes. The atom model obtained in PDB format showed unstable region in the model. These unstable regions were selected and remodelled by loop modelling. The remodelled structure was further evaluated by its stereochemical quality and energy. The quality of the remodelled structure was found to be improved. Conclusion: Evaluated 3D structure of laccase from L. edodes shows that predicted model is of good quality because maximum residues are present in favoured region of Ramachandran plot, which indicates that the stereochemical quality of predicted 3D structure is reasonably good. It suggests that this model can be used to understand molecular interaction of this laccase with the other proteins.

Utility and pitfalls of high field 3 tesla intraoperative MRI in neurosurgery: A single centre experience of 100 cases.

In India, few centers are using 1.5 Tesla intraoperative MRI systems. We are using a 3 Tesla iMRI system. We share our initial experience of 3T iMRI in neurosurgical procedures with evaluation of its utility and pitfalls. A prospective observational study conducted between August 2017 to July 2018 at Yashoda Hospital, Secunderabad. All patients undergoing iMRI guided resection of intracranial SOL were included. First 100 patients with various intracranial SOLs were included. The mean time required in shifting and image acquisition was 85.6 minutes in first 20 cases which was reduced to 37.4 minutes in next the next cases. Primary GTR was achieved in 44% cases, and residues were detected in 56%, secondary GTR was achieved in 37% cases, and surgery was discontinued in 19%. Maximum residues were detected in intraaxial sols and pituitary macroadenomas. No major iMRI associated complications were seen, minor issues involving transportation and minor contact burns were seen in 4 cases, insignificant anesthetic procedure related complications in 19 cases. As per our experience iMRI is an excellent tool to guide and improve the extent of safe resection by 37% in brain tumor surgeries. Good image quality, less time for image acquisition was observed advantages of 3T system. iMRI success depends on multidepartment coordinated teamwork and multiple iterations of the process to smoothen the workflow.

24-hours wind speed forecasting and wind power generation in La Serena (Chile)

This article presents 24-h wind speed forecasting for the city of La Serena in Chile and a methodology to explore forecasting effects on the production of wind turbine power. To that end, we used meteorological data from a weather station located in the southern zone of the hyper-arid Atacama Desert. In this area, energy resources are economically and environmentally important, and wind speed forecasting plays a vital role in the management and marketing processes of wind potential via wind farms. To contribute to the development of this energy, we propose carrying out the short-term prediction of 12 and 24 h ahead (identified as Ws( t + 12) and Ws( t + 24), respectively) using an artificial neural network with backpropagation approach. Hourly time series of wind speed, temperature, and relative humidity (from 2003 to 2006) were considered to characterize the artificial neural network in the training phase, while we used data from the year 2007 to check the efficiency of our prediction. For artificial neural network Ws( t + 12) and Ws( t + 24) models, we obtained similar performance of wind speed prediction with root mean square error of around 0.7 m s−1 and with maximum and minimum residuals of +4 and ‒4 m s−1, respectively. Based on the results, we gain a reliable tool to characterize wind speed properties in the range of 1 day within 20% of uncertainty. Moreover, this tool becomes useful to study the effects of our artificial neural network Ws( t + 12) and Ws( t + 24) models on the generation of wind energy from a wind power turbine parametrization.

Analytical Confirmation of Various Herbicides in Drinking Water Resources in Sugarcane Production Regions of Guangxi, China.

This work investigated drinking water contamination by 11 commonly used herbicides in sugarcane production areas in Guangxi, China. The work developed an analytical method for determination of these herbicides in environmental waters. This work studied herbicide residues in drinking water in Guangxi, China. The maximum residues and percent of detects were: (0.091µg/L, 29.2%, atrazine), (0.018µg/L, 8.3%, ametryne), (0.188µg/L, 8.3%, aetolaehlor), (0.139µg/L, 4%, simazine), (0.585µg/L, 62.5%, atrazine), (0.311µg/L, 33.3%, acetochlor), (0.341µg/L, 58.3%, ametryne), (1.312µg/L, 29.2%, metolachlor), (0.088µg/L, 4.2%, alachlor), (0.127µg/L, 14.3%, atrazine), and (0.453µg/L, 7.1%, metolachlor), respectively. The results demonstrated that agricultural herbicides were detected in all water samples, including tap, surface and groundwater samples. Since the residues are generally below the safe limits established by the government authorities, the monitored 11 herbicides do not significantly affect the quality of the human environment. This work will provide scientific understanding of pesticide residues in drinking water standards in terms of its consistency with precautionary human health and environmental safety.

Slice-accelerated gradient-echo echo planar imaging dynamic susceptibility contrast-enhanced MRI with blipped CAIPI: effect of increasing temporal resolution.

To assess the influence of high temporal resolution on the perfusion measurements and image quality of perfusion maps, by applying simultaneous-multi-slice acquisition (SMS) dynamic susceptibility contrast-enhanced (DSC) magnetic resonance imaging (MRI). DSC-MRI data using SMS gradient-echo echo planar imaging sequences in 10 subjects with no intracranial abnormalities were retrospectively analyzed. Three additional data sets with temporal resolution of 1.0, 1.5, and 2.0s were created from the raw data sets of 0.5s. Cerebral blood flow (CBF), cerebral blood volume, mean transit time (MTT), time to peak (TTP), and time to maximum tissue residue function (T max) measurements were performed, as was visual perfusion map analysis. The perfusion parameter for temporal resolution of 0.5s (reference) was compared with each synthesized perfusion parameter. CBF, MTT, and TTP values at temporal resolutions of 1.5 and 2.0s differed significantly from the reference. The image quality of MTT, TTP, and T max maps deteriorated with decreasing temporal resolution. The temporal resolution of DSC-MRI influences perfusion parameters and SMS DSC-MRI provides better image quality for MTT, TTP, and T max maps.

Validation of analytical method and evaluation of clothianidin residues in rice in a typical Chinese field ecosystem

SUMMARYA liquid chromatography mass spectrometry method for determination of clothianidin in brown rice, straw, rice hull, paddy water and paddy sediment was developed and residue levels were determined in the different components. The limit of quantification was set at 0·01 mg/kg for the matrices studied. Clothianidin degradation in straw, paddy water and soil was studied, and clothianidin residues in brown rice, straw, hull and paddy soil were determined. Concurrent recoveries were between 85·6 and 92·5%, with relative standard deviations ranging from 1·3 to 6·8% at three fortification levels between 0·01 and 5·0 mg/kg. The half-lives in straw, paddy water and paddy sediment were found to be 1·9–4·9, 4·1–5·0 and 4·9–6·3 days, respectively. The maximum residues in brown rice, straw, hull and paddy soil samples were 0·38, 1·88, 1·38 and 0·14 mg/kg, respectively.

Design and verification of a simple 3D dynamic model of speed skating which mimics observed forces and motions

Advice about the optimal coordination pattern for an individual speed skater, could be addressed by simulation and optimization of a biomechanical speed skating model. But before getting to this optimization approach one needs a model that can reasonably match observed behaviour. Therefore, the objective of this study is to present a verified three dimensional inverse skater model with minimal complexity, which models the speed skating motion on the straights. The model simulates the upper body transverse translation of the skater together with the forces exerted by the skates on the ice. The input of the model is the changing distance between the upper body and the skate, referred to as the leg extension (Euclidean distance in 3D space). Verification shows that the model mimics the observed forces and motions well. The model is most accurate for the position and velocity estimation (respectively 1.2% and 2.9% maximum residuals) and least accurate for the force estimations (underestimation of 4.5–10%). The model can be used to further investigate variables in the skating motion. For this, the input of the model, the leg extension, can be optimized to obtain a maximal forward velocity of the upper body.