729 research outputs found

    Study on mitigation of ammonia volatilization loss in urea through adsorbents

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    Volatilized ammonia loss (VAL) and toxicity are major disadvantages on urea amendment. In order to mitigate, slow (or) controlled release urea based fertilizers are prepared with low cost materials. Therefore, micro and nano-sized adsorbents such as zeolite, biochar were impregnated with urea @1:1 ratio for fertilizer formulations. The objective of the study was to evaluate the VAL rate. To study the effect of soil texture, incubation experiment on two different soils of Tamil Nadu (TypicHaplustalf and VerticUstropepts) with 4 physically mixed, 4 fabricated, conventional urea and control without urea determined. Fertilizer formulations were surface applied @ 250 kg N ha-1 and assessed the VAL rate for 16 days. The trapped ammonia was observed with colour change from pink to greenish and titrated with diluted sulfuric acid. Initial 3 days VAL rate was high on urea, physically mixed adsorbent fertilizers than urea impregnated fertilizers and colour change was observed on every 4-6 h of both soils. In contrast, the urea impregnated fertilizers had colour change after 9-10 h regardless of adsorbent and soils. The fabricated fertilizer observed VAL rate on gradual with low quantity on T5- Zeourea (13.5 days, 15.1 days) T6- Nano-zeourea (15.5 days, 16 days), T9- Biourea (7.5 days, 7.1 days) and T10- Nano-biourea (9 days, 9.7 days) than T2- Urea (5.5 days, 4.6 days) of Alfisols and Inceptisols respectively. Cumulative VAL rate percentage was low on T5- Zeourea (30 %, 34 %), T6- Nano-zeourea (28 %, 29.3 %) T9- Biourea (39 %, 41.5 %) and T10- Nano-biourea (36 %, 37.5 %) of Alfisols and Inceptisols, respectively on comparison with other fertilizer type.It is concluded that the surface amendment of physically mixed fertilizers not influenced any change on both soils. Urea impregnation influenced on days and cumulative VAL percentage. Our study elucidates that micro and nano porous adsorbents are potential substrate to reduce VAL rate of urea in both soils

    Biomarkers of Safety and Immune Protection for Genetically Modified Live Attenuated Leishmania Vaccines Against Visceral Leishmaniasis – Discovery and Implications

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    Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, sub-unit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in L. donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen1-/- in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated in normal individuals

    A Multi-Stage Electricity Price Forecasting For Day-Ahead Markets

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    Forecasting hourly spot prices for real-time electricity usage is a challenging task. This thesis work investigates a series of price forecasting methods for day-ahead Iberian Electricity Markets (MIBEL). The dataset from MIBEL was used to train and test multiple forecast models. A hybrid combination of Auto Regressive Integrated Moving Average (ARIMA) and Generalized Linear Model (GLM) was proposed and its Mean Percentage Error (MAPE) values were compared against several methods. For example, ARIMA, GLM, Random forest (RF) and Support Vector Machines (SVM) methods are investigated. The results indicate a significant improvement in MAPE and correlation coefficient values for the proposed hybrid ARIMA-GLM method. Forecasting hourly spot prices for real-time electricity markets are key activities in energy trading operations. This thesis work specifically develop a novel two-stage approach that uses a combination of Auto-Regressive Integrated Moving Average (ARIMA) with other models to improve residual errors in predicting the hourly spot prices. In Stage-1, the day-ahead price is forecasted using ARIMA, and then the resulting residuals are fed to another forecasting method in Stage-2. This approach was successfully tested with multiple duration periods ranging from one-week to ninety days for variables such as price, load, and temperature. A comprehensive set of 17 variables were included in the proposed model to predict the day-ahead electricity price. The results indicate a significant improvement in the Mean Absolute Percentage Error (MAPE) values compared to other present approaches. To reduce the prediction error, three types of variable selection techniques such as Relative importance using Linear Regression (LR), Multivariate Adaptive Regression Splines (MARS), and Random forest (RF) were used. Four datasets (Three months, Six months, weekday, and weekend) were used to validate the performance of the model. Three different set of variables (17, 4, 2) were used in this study. At last, three common variables selected from these feature selection approaches were tested with all these datasets. Considerable reduction in MAPE for both three and six-month dataset were achieved by these variable selection approaches. In addition, the work also investigate the application of a multi-layered deep neural network to the Iberian electric market (MIBEL) price forecasting task. A 3-month and 6-month of energy data are used to train the proposed model. The 3-month and 6-month period is treated as a historical dataset to train and predict the price for day-ahead markets. The network structure is implemented using Googleâs machine learning TensorFlow platform. Activation function such as Rectifier linear unit (ReLU) were tested to achieve a better Mean Absolute percentage error (MAPE) considering the weekday and weekend variations

    Equation of interaction diagrams for prestressed concrete columns

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    A general analysis and design equation for prestressed concrete column is proposed. This equation represents the strength interaction diagrams of prestressed concrete columns under bending about one axis and combined with axial load. The equation proposed is a modification of the one developed by Dr. Hsu, C.T. Thomas for reinforced concrete columns published in the ACI structural journal in 1988. The analytical results were compared with the results of tests on 30 eccentrically loaded prestressed columns reported by H.R. Brown and A.S. Hall. The results were in good agreement with the static analysis and the above mentioned test reports. The results of this study show that the proposed equation of interaction diagrams gives a more simple analytical tool to determine the ultimate strengths of prestressed concrete columns than those of other methods

    Re-imagining the structure and format of the recruitement, selection, and appointment of school principals: a case study of stakeholders views.

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    Masters Degree. University of KwaZulu-Natal, Durban.After South Africa became a democratic state in 1994, the department of education was faced with a huge responsibility of transforming a divided, unequal and culturally oppressive education system into a single entity that would promote principles of democracy, redress, social empowerment and equity. Fundamental to this new dispensation and the success of our schools was the appointment of school principals; this for the effective leadership and management of schools. The South African Schools Act 84 of 1996 provided a framework within which school governing bodies were required to make recommendations on the appointment of principals to the Department of Education after undergoing a selection process. The purpose of the study intended to capture the voices of educators, parents and principals serving on interview committees on the recruitment, selection and appointment of school principals. This required the collective participation of circuit managers as resource persons representing the Department of Education. This diverse group was tasked with the enormous responsibility of adjudicating on who the next head of the institution should be. Clearly the inclusion of stakeholders needed to be applauded but certainly the working and the execution of such a responsibility was bound to present challenges. Following a qualitative case study design embedded within an interpretivist paradigm the findings of this study were derived through focus group interviews. As a grounding to the research, the participants were presented with four labour relations grievance cases that emerged as a result of applicants that may have been aggrieved with the current process. The Particularist approach together with the Universalist approach constituted the theoretical framework which assisted in analysing data in terms of the format, recruitment and selection of school principals. The findings revealed that there are serious shortcomings in the current process on how school principals are recruited, selected and appointed at schools. There is a serious concern around the education department continuing to play a submissive role in this process, a substantial lack of competence on the part of parents and educators to undertake this task and a continued existence of undue influence by the unions

    Sustainable deltas in the Anthropocene

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    What are the possible trajectories of delta development over the coming decades? Trajectories will be determined by the interactions of biophysical trends such as changing sediment supplies, subsidence due to compaction of sediment and climate change, along with key socio-economic trends of migration and urbanisation, agricultural intensification, demographic transition, economic growth and structural change of the economy. Knowledge and understanding of plausible trajectories can inform management choices for deltas in the Anthropocene, including new policy perspectives and innovative adaptation. The emergence of visionary delta management plans in some large deltas, such as the Bangladesh Delta Plan 2100, is an important and necessary component. This chapter synthesises the state of knowledge and highlights key elements of science that will inform decisions on future management of deltas.<br/

    Advanced Brain Tumour Segmentation from MRI Images

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    Magnetic resonance imaging (MRI) is widely used medical technology for diagnosis of various tissue abnormalities, detection of tumors. The active development in the computerized medical image segmentation has played a vital role in scientific research. This helps the doctors to take necessary treatment in an easy manner with fast decision making. Brain tumor segmentation is a hot point in the research field of Information technology with biomedical engineering. The brain tumor segmentation is motivated by assessing tumor growth, treatment responses, computer-based surgery, treatment of radiation therapy, and developing tumor growth models. Therefore, computer-aided diagnostic system is meaningful in medical treatments to reducing the workload of doctors and giving the accurate results. This chapter explains the causes, awareness of brain tumor segmentation and its classification, MRI scanning process and its operation, brain tumor classifications, and different segmentation methodologies

    Accumulation of Heavy Metal Ions by Eichhornia Crassipes from Battery Industry Effluent under the Influence of Cattle Manure

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    Phytoremediation, an emerging technology which uses plants to remove contaminants of concern (COC) such as organic and inorganic compounds especially heavy metals (HM). The present study focuses on assessing the toxicity of heavy metals available in effluents discharged from industries and the accumulation ability of an aquatic plant, Eichhornia crassipes (water hyacinth). Phytoremedial potential of E. Crassipes and HM interaction between soil and water were evaluated in the present study under the presence of cow dung manure as an enhancer. Heterogenous accumulation of metal ions were found in the plant. Heavy metal concentration in plant parts were varied for roots and shoots. The concentration of HM ions in the plant parts were varied from root to shoot. Value of translocation factor (TF) was found to be in the region 0.5 – 0.8, with Fe has low (0.51) and Pb has high (0.77), bioconcentration factor (BCF) were in the order of Ar &gt; Ca &gt; Zn &gt; Fe &gt; Pb at both roots and shoots. Transposition factor (TrF) of all HM ions were &gt;1.5 except for Zn (1.21). E. Crassipes was found to accumulate a large amount of HM ions and could be used for efficient treatment of contaminated water

    The prevalence of work stress among Royal Malaysian Police junior officers

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    The study aims to identify relationship between factor and potential causing the work stress among Royal Malaysian Police (RMP) Junior Officers. Further in this study investigate the contribution of working conditions, workplace relationships and workload factor which is known as primary work-related work stressors. Quantitative study was chosen to conduct at RMP and the population was from various departments at RMP headquarters. Data collection methods with the questionnaires are used as the survey instruments. Total of 301 questionnaires were send to various department in RMP. The result showed the workplace relationships are the significant and main factor of work stress which is in poor supervisory and unhelpful colleagues. Meanwhile for the working conditions and workload results showed non-significant relationship with work stress. This finding will helpful to the RMP to enhance the productivity of RMP junior police officers
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