1,076 research outputs found
Low Investment is Not the Constraint on African Development
While many analysts decry the lack of sufficient investment in Africa, we find no evidence that private and public investment are productive, either in Africa as a whole (unless Botswana is included in the sample), or in the manufacturing sector in Tanzania. In this restricted sense, inadequate investment is not the major obstacle to African economic development.African Development, private and public investment, economic development
Is investment in Africa too low or too high : macro and micro evidence
The authors investigate the relationship between weak growth performance and low investment rates in Africa. The cross-country evidence suggests no direct relationship. The positive and significant coefficient on private investment appears to be driven by Botswana's presence in the sample. Allowing for the endogeneity of private investment, controlling for policy, and positing a nonlinear relationship make no difference to the conclusion. Higher investment in Africa would not by itself produce faster GDP growth. Africa's low investment and growth rates seem to be symptoms of underlying factors. To investigate those factors and to correct for some of the problems with cross-country analysis, the authors undertook a case study of manufacturing investment in Tanzania. They tried to identify why output per worker declined while capital per worker increased. Some of the usual suspects--such as shifts from high- to low-productivity subsectors, the presence of state-owned enterprises, or poor polices--did not play a significant role in this decline. Instead, low capacity utilization (possibly the by-product of poor policies) and constraints on absorptive capacity for skill acquisition seem to be critical factors. If Tanzania is not atypical,the low productivity of investment in Africa was the result of a combination of factors that occurred simultaneously, not any single factor. What does this tell us? First, we should be more careful about calling for an investment boom so that Africa can resume growth. Unless some or all of the underlying problems are addressed, the results may be disappointing. We should also be more circumspect about Africa's low savings rate; it may be low because returns to investment were so low. The relatively high level of capital flight from Africa may have been a level rational response to the lack of investment oportunities at home. Second, there is probably no single key to unlocking investment and GDP growth in Africa. All of the factors contributing to low productivity should be addressed simultaneously.Economic Growth,Achieving Shared Growth,Environmental Economics&Policies,Trade and Regional Integration,Economic Theory&Research
Simulation and Implementation of a High Performance Torque Control Scheme of IM Utilizing FPGA
Thi paper presents a novel approach to design and implementation of a high perfromane torque control scheme i.e. direct torque control with space vector modulation(DTC-SVM) of three phase induction motor using Field Programmable gate array (FPGA). The conventional direct torque control (DTC) is one of control scheme that is used commonly in induction motor control system. This method supports a very quick and precise torque response. However, the conventional DTC is not perfect and has some disadvantages. To minimize the ripples of the electromagnetic torque and flux linkage and to fix the variable switching frequency produced in the conventional DTC, this paper proposes improved DTC-SVM concept. Both simulation and experimental results show that the proposed scheme can dramatically improve the steady state performance while preserving the dynamic performance of the conventional DTC.DOI:http://dx.doi.org/10.11591/ijece.v2i3.20
Development of a high pressure compressed natural gas mixer for a 1.5 litre CNG-diesel dual engine
[Abstract]: The Computational Fluid Dynamics (CFD) analysis
software was used to study the flow behaviour of compressed
natural gas (CNG) and air in a CNG-air mixer to be introduced through the air inlet of a CNG-Diesel dual fuel stationary engine. The results of the simulation show that the Venturi mixer with more holes gives superior engine performance compared to the 4-hole Venturi mixer. Further analysis is done on the different holes mixer to investigate the effect of engine speed on the mass flow rate of CNG and the equivalence ratio Lambda. The second part of the paper represents a comparison results between the performances of a single cylinder research Compression Ignition CI engine fuelled with CNG-diesel system
and conventional CI engine fuelled by conventional diesel. The engine was equipped with the simulated Venturi mixer, the result showed significant reduction in the exhaust gas emission compared to the conventional diesel engine. The average power output generated by dual fuel engine was slightly higher than that diesel one at different engine speeds
Controlled release floating multiparticulates of metoprolol succinate by hot melt extrusion
YesWe present hot melt extrusion (HME) for the design of floating multiparticulates. Metoprolol succinate was selected as the model drug. Our foremost objective was to optimize the components EudragitŸ RS PO, polyethylene oxide (PEO) and hydroxypropyl methylcellulose (HPMC) to balance both buoyancy and controlled release. Gas generated by sodium bicarbonate in acidic medium was trapped in the polymer matrix to enable floating. EudragitŸ RS PO and PEO with sodium bicarbonate resulted in multiparticulates which exhibited rapid flotation within 3 minutes but inadequate total floating time (TFT) of 3 hours. Addition of HPMC to the matrix did not affect floating lag time (FLT), moreover TFT increased to more than 12 hours with controlled release of metoprolol succinate. Floating multiparticulates exhibited t50% of 5.24 hours and t90% of 10.12 hours. XRD and DSC analysis revealed crystalline state of drug while FTIR suggested nonexistence of chemical interaction between the drug and the other excipients. The assay, FLT, TFT and the drug release of the multiparticulates were unchanged when stored at 40 °C/75%RH for 3 months confirming stability. We present floating multiparticulates by HME which could be extrapolated to a range of other drugs. Our approach hence presents platform technology for floating multiparticulates
A Study on Oorthuva Vatham
âOorthuva Vathamâ comes under âVatha Roga Nithanamâ in Yugi vaithiya sinthamani 800 which is characterized by orthopnea, abdominal distension, pulmonary oedema, pain in the mouth, neck and chest, low grade fever, fatigue, cardiac cachexia, generalised oedema (anasarca). Since pranan is said to be the centre of the heart, it controls heart
and circulation. In Oorthuva Vatham, pranan is primarily affected and results in impaired circulation to other parts of the body. If this acute condition is not treated it leads to the affection of other thathus and udal kattugal also.
In siddha text books heart diseases are classified under the headings like Thamaraga noi, Maarbu noi and Iruthaya rogam. In Yugi vaithiya sinthamani, Yugi discussed the symptoms of congestive heart failure under the heading âOorthuva Vathamâ which is unknown to us. Heart is the first organ through which all the blood of the body passes during circulation. So heart diseases have serious effects on other systems of the body also. If properly recognized earlier, the disease can be treated more effectively and the complications can be prevented.
CONCLUSION:
The lines that were said by Yugi in Yugi vaithiya sinthamani 800 under the heading âOorthuva Vathamâ well explained the clinical condition similar to âCongestive Cardiac Failureâ. The lines of the version were well analysed on the siddha and modern parameters and the patients were thoroughly examined with clinical and bio-chemical analysis. âPoriyaal arithalâ, âPulanaal arithalâ, âVinaathalâ, âEnvagai Thervugalâ, âNeerkuriâ and âNeikuriâ helped in the proper diagnosis of the disease. Routine biochemical examination were carried out to know the general condition of all patients. Echo, ECG, X-ray chest and USG abdomen & pelvis were carried out to confirm the diagnosis.
As a siddha physician we know the importance of our âNoi Illa Neriâ principles which can only prevent our people from many of these ailments. These principles were said by learned Yogis for the sake of our people. We should guide the people in the proper way and make them to follow these principles to achieve the WHO target (Health for all by 2000 AD)
Analysing an Imbalanced Stroke Prediction Dataset Using Machine Learning Techniques
A stroke is a medical condition characterized by the rupture of blood vessels within the brain which can lead to brain damage. Various symptoms may be exhibited when the brain's supply of blood and essential nutrients is disrupted. To forecast the possibility of brain stroke occurring at an early stage using Machine Learning (ML) and Deep Learning (DL) is the main objective of this study. Timely detection of the various warning signs of a stroke can significantly reduce its severity. This paper performed a comprehensive analysis of features to enhance stroke prediction effectiveness. A reliable dataset for stroke prediction is taken from the Kaggle website to gauge the effectiveness of the proposed algorithm. The dataset has a class imbalance problem which means the total number of negative samples is higher than the total number of positive samples. The results are reported based on a balanced dataset created using oversampling techniques. The proposed work used Smote and Adasyn to handle imbalanced problem for better evaluation metrics. Additionally, the hybrid Neural Network and Random Forest (NN-RF) utilizing the balanced dataset by Adasyn oversampling achieves the highest F1-score of 75% compared to the original unbalanced dataset and other benchmarking algorithms. The proposed algorithm with balanced data utilizing hybrid NN-RF achieves an accuracy of 84%. Advanced ML techniques coupled with thorough data analysis enhance stroke prediction. This study underscores the significance of data-driven methodologies, resulting in improved accuracy and comprehension of stroke risk factors. Applying these methodologies to medical fields can enhance patient care and public health outcomes. By integrating our discoveries, we can enhance the efficiency and effectiveness of the public health system
Intratumoral heterogeneity analysis reveals hidden associations between protein expression losses and patient survival in clear cell renal cell carcinoma.
Intratumoral heterogeneity (ITH) is a prominent feature of kidney cancer. It is not known whether it has utility in finding associations between protein expression and clinical parameters. We used ITH that is detected by immunohistochemistry (IHC) to aid the association analysis between the loss of SWI/SNF components and clinical parameters.160 ccRCC tumors (40 per tumor stage) were used to generate tissue microarray (TMA). Four foci from different regions of each tumor were selected. IHC was performed against PBRM1, ARID1A, SETD2, SMARCA4, and SMARCA2. Statistical analyses were performed to correlate biomarker losses with patho-clinical parameters. Categorical variables were compared between groups using Fisher\u27s exact tests. Univariate and multivariable analyses were used to correlate biomarker changes and patient survivals. Multivariable analyses were performed by constructing decision trees using the classification and regression trees (CART) methodology. IHC detected widespread ITH in ccRCC tumors. The statistical analysis of the Truncal loss (root loss) found additional correlations between biomarker losses and tumor stages than the traditional Loss in tumor (total) . Losses of SMARCA4 or SMARCA2 significantly improved prognosis for overall survival (OS). Losses of PBRM1, ARID1A or SETD2 had the opposite effect. Thus Truncal Loss analysis revealed hidden links between protein losses and patient survival in ccRCC
Compensation of Voltage Sag and Swell Using SMES Based Dynamic Voltage Restorer
 Conducting Magnetic Energy Storage (SMES) is portrayed by profoundly proficient vitality storage. It has fast reaction and power controllability and is relied upon to add to brilliant intensity of the power grid. SMES innovation can possibly bring genuine power storage trademark and furthermore high power and vitality thickness for momentary reaction. This normal for SMES used to shield buyers from the network voltage variances like sag, swell and interference. This paper examinations the activity guideline of the SMES based DVR and its structure depends on basic PI control technique to repay voltage droops, swell and intrusion. Utilizing MATLAB/SIMULINK, the models of the SMES based DVR is set up, and the re-enactment tests are performed to assess the grid disturbances
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