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Steam gasification of biomass with subsequent syngas adjustment using shift reaction for syngas production: An Aspen Plus model
No full textAbstractA simulation model of biomass gasification for syngas production with steam as gasifying agent and subsequent syngas adjustment has been developed using Aspen Plus. The developed model is based on Gibbs free energy minimization applying the restricted equilibrium method. The objective is to study the effect of important parameters such as gasification temperature, steam to biomass ratio and shift reaction temperature on hydrogen concentration, CO concentration, CO conversion, CO2 conversion and H2/CO ratio in the syngas. Simulations were performed for different biomass feedstocks to predict their syngas composition. The hydrogen and CO concentrations were altered such that the H2/CO molar ratio in the syngas composition gets adjusted close to a value of 2.15 as required for FT synthesis by the shift reaction. The present model has been validated with experimental data from literature on steam biomass gasification conducted in a research scale fluidized bed gasifier. The product gas obtained from steam gasification of food wastes resulted in a composition with a H2/CO molar ratio close to 2.15 which can be directly fed to a Fischer-Tropsch synthesis plant whereas remaining feedstocks requires a syngas adjustment either by WGS or RWGS reactions to achieve H2/CO molar ratio close to 2.15
Revised diagnostic criteria for neurocysticercosis
No full textAbstractBackgroundA unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings.MethodsCysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set.ResultsThis revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure.ConclusionsThis revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios
The EU Water Framework Directive: From great expectations to problems with implementation
No full textAbstractThe Water Framework Directive 2000/60/EC (WFD) is widely accepted as the most substantial and ambitious piece of European environmental legislation to date. It has been referred to as a once in a generation opportunity to restore Europe's waters and a potential template for future environmental regulations. However, fifteen years since it was adopted, and with many problems and delays in its implementation, the WFD has not delivered its main objectives of non-deterioration of water status and the achievement of good status for all EU waters. Putting aside the daunting technical and organisational challenges of its implementation, this paper aims to shed light on why the great expectations that came with the WFD have not yet been fully realised. It reviews how the Directive has been interpreted, focusing on its intentions and how they were applied. The findings reveal the absence of the paradigm shift towards the systems (integrated) thinking that the WFD was grounded on, as a fundamental problem with its implementation. This is also evident in cases where the Directive has been criticised as a policy tool or when implementation efforts were reviewed, indicating misunderstandings even of its core principles. This inherent departure from the Directive's systemic intention and methodological approach needs further investigation, as it could be the reason behind many of its problems and delays. Unless current implementation efforts are reviewed or revised in light of this, enabling the paradigm shift required to ensure a more sustainable and holistic approach to water management, the fading aspirations of the initial great expectations that came with the Directive could disappear for good
In vitro biocontrol activity of halotolerant Streptomyces aureofaciens K20: A potent antagonist against Macrophomina phaseolina (Tassi) Goid
No full textAbstractA halotolerant actinobacterial strain isolated from salinity affected soil of Eastern Indo-Gangetic plains (IGP), Uttar Pradesh, India, was characterised for its antagonistic potential against Macrophomina phaseolina by dual-culture assay. It was shown to effectively inhibit the growth of M. phaseolina with an inhibition zone of 27±1.33mm. Further the actinobacterial strain was evaluated for its plant growth promoting (PGP) properties and its ability to produce biocontrol related extracellular enzymes viz. amylase, protease, cellulase, chitinase, gelatinase and urease. The results revealed that the actinobacterial strain had PGP potential along with positive assay for amylase, chitinase and urease. The interaction study between antagonist strain and fungal pathogen, performed by scanning electron microscopy technique revealed that the actinobacterium was able to damage fungal mycelia may be due to chitinase, establishing its role as a potential antagonist against M. phaseolina. The actinobacterial isolate was characterised by 16S rDNA gene sequencing, and was identified as Streptomyces genera. The identified gene sequence was deposited to NCBI GenBank with an accession number KP331758
A catchment-scale method to simulating the impact of historical nitrate loading from agricultural land on the nitrate-concentration trends in the sandstone aquifers in the Eden Valley, UK
No full textAbstractNitrate water pollution, which is mainly caused by agricultural activities, remains an international problem. It can cause serious long-term environmental and human health issues due to nitrate time-lag in the groundwater system. However, the nitrate subsurface legacy issue has rarely been considered in environmental water management. We have developed a simple catchment-scale approach to investigate the impact of historical nitrate loading from agricultural land on the nitrate-concentration trends in sandstones, which represent major aquifers in the Eden Valley, UK. The model developed considers the spatio-temporal nitrate loading, low permeability superficial deposits, dual-porosity unsaturated zones, and nitrate dilution in aquifers. Monte Carlo simulations were undertaken to analyse parameter sensitivity and calibrate the model using observed datasets. Time series of annual average nitrate concentrations from 1925 to 2150 were generated for four aquifer zones in the study area. The results show that the nitrate concentrations in ‘St Bees Sandstones’, ‘silicified Penrith Sandstones’, and ‘non-silicified Penrith Sandstones’ keep rising or stay high before declining to stable levels, whilst that in ‘interbedded Brockram Penrith Sandstones’ will level off after a slight decrease. This study can help policymakers better understand local nitrate-legacy issues. It also provides a framework for informing the long-term impact and timescale of different scenarios introduced to deliver water-quality compliance. This model requires relatively modest parameterisation and is readily transferable to other areas
Simultaneous determination of dissolved inorganic chromium species in wastewater/natural waters by surfactant sensitized catalytic kinetic spectrophotometry
No full textAbstractA simple, rapid, highly accurate and sensitive kinetic method is proposed for determining chromium(VI). The method is based on its catalytic effect on the oxidation of Celestine blue (CB+) by H2O2 in the presence of 2,2′-bipyridyl (Bipyr) and cetylpyridinium chloride (CPC) at pH 6.50. The reaction was monitored spectrophotometrically by measuring the absorbance of indicator dye at 645nm. The analytical variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine and speciate chromium in a linear range of 5–200μgL−1 with a detection limit of 0.65μgL−1. The recoveries and relative standard deviations (RSDs) for the determination of 10, 25, 75 and 150μgL−1 Cr(VI) (n: 5) were in the range of 99.0–99.8% and 0.2–3.5%, respectively. The selectivity was also studied and greatly enhanced by adding a suitable masking mixture. The method was successfully applied to the simultaneous analysis of Cr(III) and Cr(VI) in natural water and waste water samples with a recovery changing in the range of 95–103% for Cr(III) and 100–104% for Cr(VI). Its accuracy was validated by the analysis of certified reference materials with good agreement between certified and found values
Shorter recovery can be achieved from using walking boot after operative treatment of an ankle fracture
No full textAbstractBackground/ObjectiveAnkle fractures, even if treated surgically, usually take a long time to heal. For all patients with ankle fracture, immobilisation is a critical part of treatment. Short-leg walking boots (WBs) have been reported to be an effective alternative to plaster casts (PCs) that could shorten this postoperative recuperative period. The aim of this study was to compare the functional recovery of a conventional PC with that of a WB after surgery for ankle fractures.MethodsForty-seven patients (mean age, 53.9±12 years) who had undergone surgical operation for an unstable ankle fracture from January 2008 to October 2014 were reviewed retrospectively. Either a PC or a WB was prescribed postoperatively, with 25 patients and 22 patients, respectively. The time that it took the patient to stand unipedal on the affected side after allowing full-weight bear and to walk without crutches were used for assessment of functional recovery. The prevalence of postoperative loss of reduction and nonunion was also reviewed.ResultsBoth the time of being able to stand unipedal on the injured side and to walk without crutches were significantly shorter in patients using WBs (WB, 2.6 weeks; PC, 4.5 weeks, p=0.01; WB, 1.4 weeks; PC, 3.1 weeks, p=0.03). There were no patients with loss of reduction or nonunion.ConclusionPatients who used WBs showed a significantly faster recovery. WBs have an adjustable heel lift that allows users to change the ankle position slightly plantarflexed that helps walking in a postoperative swollen ankle. WBs are easy to slip on, and it is easy to adjust the ankle position in conformity with swelling so that the least painful position could be maintained during walking. WBs have good fixity to allow immediate weight-bearing postoperatively, and there were no cases with loss of reduction postoperatively. The Rocker bottom design minimises the sagittal plane motion in the specific joint of the foot, which also facilitates the course of recuperation. An ankle fracture fixed appropriately endures loading when a WB is used. The WB treatment results in faster functional recovery, allowing the patients to return to normal activity at a faster rate
Three-dimensional echocardiography of a tricuspid valve papillary fibroelastoma
No full textAbstractPapillary fibroelastomas (PFE) on tricuspid valve (TV) are rare, accounting for fewer than 11% of all PFE. Most often they are asymptomatic, and detect on mitral valve. We report a case of a typical chest pain found to be due to papillary fibroelastoma of the tricuspid valve
Competition and financial constraints: A two-sided story
No full textAbstractThis paper examines the relation between competitive pressure and financial constraints using firm-level survey data from 27 emerging economies of Eastern Europe and Central Asia for the years 2005 and 2009. In the empirical analysis, we disentangle the impact of product market competition on the demand and supply of credit. Our results support the hypothesis that competitive pressure on borrowers affects both sides of the credit market. We find that in industries with greater competitive pressure firms' demand for credit is typically higher but a greater proportion of firms are discouraged from loan application due to greater cost of credit. Interestingly, we find the detrimental effect of competitive pressure on credit access breaks down when firms are audited, when they can pledge collateral and when they engage in export activities. These results point to the role of competitive pressure in the lenders' information set when limited information is available
Resección total del mesorrecto por vía transanal en cáncer de recto. Análisis de resultados de una serie preliminar en un hospital universitario
No full textResumenIntroducciónLa resección total del mesorrecto por vía transanal es un abordaje híbrido que combina el uso de una plataforma transanal y laparoscopia convencional.ObjetivosRealizar el análisis de casos seleccionados con cáncer de recto medio e inferior en los cuales se utilizó un abordaje transanal combinado para su resolución y la descripción de la técnica quirúrgica.Materiales y métodosCorresponde a una serie prospectiva de pacientes con diagnóstico de cáncer de recto de tercio medio e inferior con resección mesorrectal asistida por monopuerto endoanal entre octubre de 2012 y diciembre de 2015, en Hospital Clínico Universidad de Chile. Se utilizó estadística descriptiva para el análisis de los datos.ResultadosFueron sometidos a cirugía por cáncer de recto medio e inferior un total de 29 pacientes utilizando monopuerto transanal. De estos, 22 fueron de sexo masculino y 7 de sexo femenino, con edad promedio de 55,5 años e IMC de 26,4. La distancia media al margen anal fue 4,8cm. Todos recibieron neoadyuvancia. Se realizaron 17 Ta-TME (58,6%) y 12 Ta-TME con abordaje interesfintérico (41,4%). La anastomosis fue coloanal manual en 15 pacientes (51,7%) y grapada en 14 (48,3%). El abordaje laparoscópico se utilizó en 26 pacientes y el abierto en 3, registrando 4 conversiones (15,4%). El tiempo operatorio promedio fue de 282min. La estadía hospitalaria media fue de 9 días.ConclusiónEl monopuerto endoanal aparece como una herramienta útil en la disección total del mesorrecto por su seguridad y factibilidad. Creemos que es necesaria la realización de trabajos prospectivos aleatorizados, donde es relevante la comparación de resultados oncológicos y funcionales a largo plazo.AbstractIntroductionTransanal total mesorectal excision is a hybrid approach that combines the use of a conventional laparoscopic and a transanal platform.ObjectivesTo conduct an analysis of selected cases with medium and lower rectal cancer, were a combined transanal approach was used and description of the surgical technique.Materials and methodsProspective series of patients diagnosed with middle and lower third rectal cancer with mesorectal resection assisted by endoanal single port, between October 2012 and December 2015 at University of Chile Clinical Hospital. Descriptive statistics were used for data analysis.ResultsA total of 29 patients underwent surgery for middle and lower rectal cancer using a transanal single port. Gender distribution was 22 male and 7 female patients, with a mean age of 55.5 years and a mean BMI of 26.4. The mean distance from the anal margin was 4.8cm. All patients received neoadjuvant therapy. The surgeries performed were 17 Ta-TME (58.6%) and 12 Ta-TME with intersphincteric approach (41.4%). The colo-anal anastomosis was hand sewn in 15 patients (51.7%), and stapled in 14 (48.3%). The laparoscopic approach was used in 26 patients and the open approach in 3, with 4 conversions (15.4%). The mean operative time was 282min. The mean hospital stay was 9 days.ConclusionThe endoanal single port appears as a useful tool in total mesorectal dissection for its safety and feasibility. We believe we need randomized prospective studies, where comparison of oncological and functional long-term results is relevant