105 research outputs found
Elevated Temperature Performance of Multiple-Blended Binder Concretes
Concretes that contain binary-blended binders (BBB) and ternary-blended binders (TBB) incorporating thermally activated alum sludge ash (AASA), silica fume (SF), ground-granulated blast-furnace slag (GGBS) and palm oil fuel ash (POFA) are exposed to temperatures as high as 800 °C. The water-binder ratio of the multiple-blended binder (MBB) concretes was 0.30, and the total binder and polypropylene (PP) fibre contents were 493 and 1.8 kg/m3, respectively. The elevated temperature performance of the MBB concretes is evaluated in terms of the mass loss, compressive strength, ultrasonic pulse velocity (UPV) and surface cracks. The concrete strength deteriorated significantly due to elevated temperature up to 800 °C, but the residual strength of the BBB containing 15 % AASA was higher than that of the control and 20 % AASA concretes. High-temperature exposure decreased measured UPV values. The concrete weight loss was more pronounced for TBB concretes. The elevated temperature performance of all of the TBB concretes was better than that of the BBB concretes with the same AASA replacement levels. It was observed that PP fibres help reduce spalling. BBB concrete containing 15 % AASA combined with either SF or GGBS or POFA exhibits superior performance at elevated temperature than Portland cement concrete at the same mix design proportion
Production of a Laccase from Botrytis cinerea (DSMZ 877) and Application for Textile Phenolic Dye Decolorization
AbstractIn this study, the production, partial purification and characterization of a laccase from Botrytis cinerea strain (DSMZ No. 877) was studied. The production of laccase was induced using copper sulphate and Gallic acid as inducers. The maximum laccase activity observed during B. cinerea growth in the presence of 0.1% Gallic acid was 2600 UL−1. Laccase purification was performed by precipitated the enzyme with 90% ammonium sulphate followed by gel filtration chromatography. The optimum pH for the laccase activity was observed at acidic pH values (close to pH 3.5 - 4.6), while the optimum temperature was 70°C. The ability of the produced laccase as well as the laccase from T. versicolor to catalyse the decolorization of a phenolic dye (phenol red) was also investigated using natural and synthetic mediators. The higher decolorization activity was observed with 1–hydroxybenzotriazole (HBT) as mediator at pH 4.5 and temperature 30° C
Genetic Variation of Trichomonas vaginalis Isolates from Iraqi Women: Association with Fertility and Cervical Abnormalities
الخلفية/ الهدف: داء المشعرات المهبلية هو واحد من أكثر الأمراض غير الفيروسية المنقولة جنسيا, يسببه طفيلي Trichomonas vaginalis. لا يعرف سوى القليل عن التنوع الوراثي والهيكل المعيشي لهذا الطفيلي. هدفت هذه الدراسة إلى تحديد التنوع الوراثي لعزلات طفيلي المشعرات المهبلية وارتباطه بالخصوبة وتشوهات عنق الرحم.
الأساليب: تم تعيين مجموعة من 154 امرأة عراقية ممن يراجعن قسم الولادة والامراض النسائية في عدد من مستشفيات محافظة بغداد خلال الفترة من شباط 2013 إلى نيسان 2014 ، لهذه الدراسة. تم استخراج الحمض النووي لعزلات الطفيلي من مزروع المسحات المهبلية. تم إجراء طريقة التنميط التتابعي المتعدد المواقع (MLST) لستة من الجينات المرجعية لدراسة التغيرات الجينية.
النتائج: ثلاث وخمسون امرأة (34.41 ٪) قد أعطت نتيجة موجبة للأصابة بالطفيلي T.vaginalis. أظهرت طريقة MLST وجود اليلات مختلفة. وكان للمورث glut أعلى درجة من التغايرات بين المورثات الستة.
الاستنتاج: يمكن الاستنتاج أن التنوع الوراثي في الكائن الحي نفسه في عزلات العراق ، يمكن أن يرتبط بالنتائج السريرية. هناك حاجة إلى مزيد من الدراسات MLST لمقارنة عدد أكبر من العزلات من مختلف المواقع ودراسة الطفرات المحددة في المورثات المرجعية لنساء اللاتي يعانين من العقم ومن تشوهات عنق الرحم.
الكلمات المفتاحية: طفيلي المشعرات المهبلية. التغاير الوراثي, الخصوبة, تشوهات عنق الرحم, طريقة التنميط التتابعي المتعدد المواقع.Background: Trichomoniasis, is one of the most common non-viral sexually transmitted diseases caused by the parasite Trichomonas vaginalis. Little is known about the genetic diversity and population structure of this parasite. This study aimed to determine the genetic diversity of T. vaginalis isolated from Iraqi women and its association with the fertility and the cervical abnormalities.
Methods: Overall, 154 Iraqi women attending the Gynecology Outpatient departments in Baghdad Province, Iraq from February 2013 to April 2014, were enrolled in this study. DNA of T. vaginalis isolates was extracted from the culture of high vaginal swabs. Multilocus sequence typing (MLST) method for six housekeeping genes was done in studying the genetic variations.
Results: Fifty-three women (34.41%) were positive for T. vaginalis. MLST method resulted in different alleles. With glutaminase gene, the highest degree of variation was found among the six genes.
Conclusion: The genetic diversity in the organism itself in Iraqi isolates can associate with clinical outcome. Further MLST studies are needed to compare a larger number of isolates from different localities and correlate the certain mutations in housekeeping genes to infertile women and patients with cervical abnormalities
National Urban Database and Access Portal Tool, NUDAPT
Based on the need for advanced treatments of high resolution urban morphological features (e.g., buildings, trees) in meteorological, dispersion, air quality and human exposure modeling systems for future urban applications, a new project was launched called the National Urban Database and Access Portal Tool (NUDAPT). NUDAPT is sponsored by the U.S. Environmental Protection Agency (USEPA) and involves collaborations and contributions from many groups including federal and state agencies and from private and academic institutions here and in other countries. It is designed to produce and provide gridded fields of urban canopy parameters for various new and advanced descriptions of model physics to improve urban simulations given the availability of new high-resolution data of buildings, vegetation, and land use. Additional information include gridded anthropogenic heating and population data is incorporated to further improve urban simulations and to encourage and facilitate decision support and application linkages to human exposure models. An important core-design feature is the utilization of web portal technology to enable NUDAPT to be a Community based system. This web-based portal technology will facilitate customizing of data handling and retrievals (http://www.nudapt.org). This article provides an overview of NUDAPT and several example applications
Project ATLANTA (ATlanta Land-use ANalysis: Temperature and Air quality): A Study of how the Urban Landscape Affects Meteorology and Air Quality Through Time
It is our intent through this investigation to help facilitate measures that can be Project ATLANTA (ATlanta Land-use ANalysis: applied to mitigate climatological or air quality Temperature and Air-quality) is a NASA Earth degradation, or to design alternate measures to sustain Observing System (EOS) Interdisciplinary Science or improve the overall urban environment in the future. investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta. The primary objectives for this research effort are: 1) To In the last half of the 20th century, Atlanta, investigate and model the relationship between Atlanta Georgia has risen as the premier commercial, urban growth, land cover change, and the development industrial, and transportation urban area of the of the urban heat island phenomenon through time at southeastern United States. The rapid growth of the nested spatial scales from local to regional; 2) To Atlanta area, particularly within the last 25 years, has investigate and model the relationship between Atlanta made Atlanta one of the fastest growing metropolitan urban growth and land cover change on air quality areas in the United States. The population of the through time at nested spatial scales from local to Atlanta metropolitan area increased 27% between 1970 regional; and 3) To model the overall effects of urban and 1980, and 33% between 1980-1990 (Research development on surface energy budget characteristics Atlanta, Inc., 1993). Concomitant with this high rate of across the Atlanta urban landscape through time at population growth, has been an explosive growth in nested spatial scales from local to regional. Our key retail, industrial, commercial, and transportation goal is to derive a better scientific understanding of how services within the Atlanta region. This has resulted in land cover changes associated with urbanization in the tremendous land cover change dynamics within the Atlanta area, principally in transforming forest lands to metropolitan region, wherein urbanization has urban land covers through time, has, and will, effect consumed vast acreas of land adjacent to the city local and regional climate, surface energy flux, and air proper and has pushed the rural/urban fringe farther quality characteristics. Allied with this goal is the and farther away from the original Atlanta urban core. prospect that the results from this research can be An enormous transition of land from forest and applied by urban planners, environmental managers agriculture to urban land uses has occurred in the and other decision-makers, for determining how Atlanta area in the last 25 years, along with subsequent urbanization has impacted the climate and overal
Hybrid Social Grouping Algorithm-Perturb and Observe Power Tracking Scheme for Partially Shaded Photovoltaic Array
This research work emphasizes proposing a hybrid social grouping algorithm (SGA) and perturb and observe (P&O) scheme for tracking the global power peak in a partially shaded photovoltaic (PV) array. PV panels getting shaded, even partially, exhibits multiple power peaks, and hence conventional maximum power point tracking (MPPT) algorithms fail in tracking the maximum power peak as it gets deceived by local maxima. Most of the prevailing global search algorithms suffer in performance due to the stochastic search which consumes time even after nearing the global power peak. Therefore, a hybridization of the global search algorithm and the conventional algorithm will be a prudent solution. SGA, a global search algorithm based on individual and group cognizant behaviour, has been hybridized with a well-entrenched P&O algorithm that complements each other in achieving the global power peak swiftly. The hybridized algorithm achieves the global power peak in 0.4 seconds faster than the stand-alone SGA algorithm during complex shading conditions. The proposed scheme has been implemented for an 800 W PV array in a MATLAB simulation and validated experimentally in a hardware setup using a SAS1000L solar array simulator-programmable source, a DC-DC converter, and a dSPACE 1104 controller. The simulation and experimental results reveal that the proposed search scheme is very competent in converging towards the global maximum through SGA first and achieving the peak point through P&O. The proposed scheme has also been tested for a dynamic shading pattern, and it is evident that the proposed scheme outperforms its counterparts in terms of convergence time
Pilot actions in European cities - Stuttgart
The field of urban climatology has a long tradition in Stuttgart. It exists as discipline in Stuttgart since 1938. Stuttgart was the first city to establish its own Department of Climatology to research ways of improving the flow of fresh air into the city and to reduce thermal stress in most populated city districts. The specialist department of Urban Climatology, within the Environmental Protection Office, deals with tasks relating to environmental meteorology within the scope of air pollution control and also relating to urban and global climate protection. So in Stuttgart the urban heat island phenomenon (UHI) is studied for several decades, leading to a high level understanding of the UHI and the problems which it causes. The UHI causes an increase in air temperatures and thermal stress, that are identified as most negative impacts on human health and urban living. In the view of global climate change and the predicted temperature rise for the Stuttgart region of 1.5–2 K in this century, the negative impacts of UHI on human health and urban living will become more problematic in the future. According to the results of climate models the frequency of very hot days is expected to jump by nearly 30 % at the end of the century. The rising temperatures due to the global climate change in combination with the temperature shift as a result of the UHI will intensify the heat stress in urban areas, that leads to a significant increasing risk to human health, in particular to the very young and elderly. Not least due its importance for the human health and the quality of urban life in Stuttgart, the UHI is focussed by urban planners and is noticed by the future development of the city.
Within the pilot action study in Stuttgart several measure for reducing the UHI and the impacts on urban living and human health are analysed by the use of micro-scale and macro-scale simulations. With the help of these analysis realisable measure are selected. The most useful measures are implemented into a developmoutline plan for the redevelopment of the city district Stuttgart-West by the municipal urban planners
The Integrated WRF/Urban Modeling System: Development, Evaluation, and Applications to Urban Environmental Problems
To bridge the gaps between traditional mesoscale modeling and microscale modeling, the National Center for Atmospheric Research (NCAR), in collaboration with other agencies and research groups, has developed an integrated urban modeling system coupled to the Weather Research and Forecasting (WRF) model as a community tool to address urban environmental issues. The core of this WRF/urban modeling system consists of: 1) three methods with different degrees of freedom to parameterize urban surface processes, ranging from a simple bulk parameterization to a sophisticated multi-layer urban canopy model with an indoor outdoor exchange sub-model that directly interacts with the atmospheric boundary layer, 2) coupling to fine-scale Computational Fluid Dynamic (CFD) Reynolds-averaged Navier–Stokes (RANS) and Large-Eddy Simulation (LES) models for Transport and Dispersion (T&D) applications, 3) procedures to incorporate high-resolution urban land-use, building morphology, and anthropogenic heating data using the National Urban Database and Access Portal Tool (NUDAPT), and 4) an urbanized high-resolution land-data assimilation system (u-HRLDAS). This paper provides an overview of this modeling system; addresses the daunting challenges of initializing the coupled WRF/urban model and of specifying the potentially vast number of parameters required to execute the WRF/urban model; explores the model sensitivity to these urban parameters; and evaluates the ability of WRF/urban to capture urban heat islands, complex boundary layer structures aloft, and urban plume T&D for several major metropolitan regions. Recent applications of this modeling system illustrate its promising utility, as a regional climate-modeling tool, to investigate impacts of future urbanization on regional meteorological conditions and on air quality under future climate change scenarios
Pyrolysis, kinetics analysis, thermodynamics parameters and reaction mechanism of Typha latifolia to evaluate its bioenergy potential
The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.biortech.2017.08.162 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This work was focused on understanding the pyrolysis of Typha latifolia. Kinetics, thermodynamics parameters and pyrolysis reaction mechanism were studied using thermogravimetric data. Based on activation energies and conversion points, two regions of pyrolysis were established. Region-I occurred between the conversion rate 0.1 to 0.4 with peak temperatures 538K, 555K, 556K at the heating rates of 10 Kmin-1, 30 Kmin-1, and 50 Kmin-1, respectively. Similarly, the Region-II occurred between 0.4 to 0.8 with peak temperatures of 606K, 621K, 623K at same heating rates. The best model was diffusion mechanism in Region-I. In Region-II, the reaction order was shown to be 2nd and 3rd. The values of activation energy calculated using FWO and KAS methods (134-204 kJ mol-1) remained same in both regions reflecting that the best reaction mechanism was predicted. Kinetics and thermodynamic parameters including E, ΔH, ΔS, ΔG shown that T. latifolia biomass is a remarkable feedstock for bioenergy.Higher Education Commission Pakista
National Urban Database and Access Portal Tool
Based on the need for advanced treatments of high-resolution urban morphological features (e.g., buildings and trees) in meteorological, dispersion, air quality, and human-exposure modeling systems for future urban applications, a new project was launched called the National Urban Database and Access Portal Tool (NUDAPT). NUDAPT is sponsored by the U.S. Environmental Protection Agency (U.S. EPA) and involves collaborations and contributions from many groups, including federal and state agencies, and from private and academic institutions here and in other countries. It is designed to produce and provide gridded fields of urban canopy parameters for various new and advanced descriptions of model physics to improve urban simulations, given the availability of new high-resolution data of buildings, vegetation, and land use. Additional information, including gridded anthropogenic heating (AH) and population data, is incorporated to further improve urban simulations and to encourage and facilitate decision support and application linkages to human exposure models. An important core-design feature is the utilization of Web portal technology to enable NUDAPT to be a âcommunityâ based system. This Web-based portal technology will facilitate the customizing of data handling and retrievals
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