1,072 research outputs found
Consistent Measurement of Fiscal Deficit and Debt of States in India
There are differences in the definition of debt used by different bodies like the state governments, Reserve Bank of India, the Office of Comptroller and Auditor General of India and the Eleventh Finance Commission. Moreover, none of these definitions satisfy the criterion that fiscal deficit in a given year should equal the sum of increase in debt and monetisation. This paper attempts to estimate debt in a theoretically consistent and appropriate manner for 15 non special category states and 10 special category states for the period 1989-90 to 2003-04, which are then used to obtain effective interest rates for these states. We observe that non-special category states have a significantly greater probability of fiscal sustainability than the special category states. Moreover, when the trends in the proportion of debt of each state in the aggregate of all states is compared with trends in similar proportions of fiscal transfers from the centre and that in primary deficit on own account, we find that certain states have benefited by largesse from the centre despite a consistent bad performance while certain performing states have been penalized by reduced fiscal transfers.
Compositional Set Invariance in Network Systems with Assume-Guarantee Contracts
This paper presents an assume-guarantee reasoning approach to the computation
of robust invariant sets for network systems. Parameterized signal temporal
logic (pSTL) is used to formally describe the behaviors of the subsystems,
which we use as the template for the contract. We show that set invariance can
be proved with a valid assume-guarantee contract by reasoning about individual
subsystems. If a valid assume-guarantee contract with monotonic pSTL template
is known, it can be further refined by value iteration. When such a contract is
not known, an epigraph method is proposed to solve for a contract that is
valid, ---an approach that has linear complexity for a sparse network. A
microgrid example is used to demonstrate the proposed method. The simulation
result shows that together with control barrier functions, the states of all
the subsystems can be bounded inside the individual robust invariant sets.Comment: Submitted to 2019 American Control Conferenc
Generalized Least Energy of Separation for Desalination and Other Chemical Separation Processes
Increasing global demand for fresh water is driving the development and implementation of a wide variety of seawater desalination technologies driven by different combinations of heat, work, and chemical energy. This paper develops a consistent basis for comparing the energy consumption of such technologies using Second Law efficiency. The Second Law efficiency for a chemical separation process is defined in terms of the useful exergy output, which is the minimum least work of separation required to extract a unit of product from a feed stream of a given composition. For a desalination process, this is the minimum least work of separation for producing one kilogram of product water from feed of a given salinity. While definitions in terms of work and heat input have been proposed before, this work generalizes the Second Law efficiency to allow for systems that operate on a combination of energy inputs, including fuel. The generalized equation is then evaluated through a parametric study considering work input, heat inputs at various temperatures, and various chemical fuel inputs. Further, since most modern, large-scale desalination plants operate in cogeneration schemes, a methodology for correctly evaluating Second Law efficiency for the desalination plant based on primary energy inputs is demonstrated. It is shown that, from a strictly energetic point of view and based on currently available technology, cogeneration using electricity to power a reverse osmosis system is energetically superior to thermal systems such as multiple effect distillation and multistage flash distillation, despite the very low grade heat input normally applied in those systems.Center for Clean Water and Clean Energy at MIT and KFUPM (Project R13-CW-10
Drug utilization study of anti-hypertensive drugs and prescription pattern adherence with joint national committee-8 guideline
Background: Hypertension is a major and serious non-communicable disease. It is also a major risk factor for cerebrovascular strokes, coronary artery thrombosis, and renal failure. The overall prevalence of hypertension in India is 29.8%. Joint national committee-8 guidelines on prevention, detection, evaluation, and treatment of high blood pressure highlight that aggressive blood pressure control is essential for the reduction of hypertension-associated morbidity and mortality.Methods: It was a cross-sectional, observational study. Prescriptions were collected from four pharmacy stores located in four different areas of Ahmedabad over a period of 2 months. These were analysed along with relevant co-morbidities and, the level of prescription pattern adherence was assessed as per JNC 8 guidelines. Appropriate statistical tests were applied for analyses of collected data.Results: A total of 321 prescriptions were collected. Out of them, 186(57.9%) were prescribed to male patients while 135 (42.1%) were for female patients. Mean systolic and diastolic blood pressure was found to be 152 mmHg and 91 mmHg respectively. The mean age of the patients was found to be 44.63 years. A total of 209 (65.1%), 91 (28.34%), 21 (6.54%) prescriptions had monotherapy, dual therapy, and polytherapy for treating hypertension respectively. Amlodipine (CCBs) was found to be the most commonly prescribed medicine as a monotherapy. The overall adherence rate was found to be 77.88%.Conclusions: The present study demonstrated that medical professionals are not completely adhering to standard guidelines while prescribing antihypertensive drugs. There is substantial scope for improvement, particularly the utilization of antihypertensive agents in patients of the pre-hypertension category, where non-pharmacological measures play an important role to treat the condition.
Irreversibilities and nonidealities in desalination systems
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 207-220).Energy requirements for desalination systems must be reduced to meet increasing global demand for fresh water. This thesis identifies thermodynamic limits for the energetic performance of desalination systems and establishes the importance of irreversibilities and solution composition to the actual performance obtained. Least work of separation for a desalination system is derived and generalized to apply to all chemical separation processes driven by some combination of work, heat, and chemical energy (fuel) input. At infinitesimal recovery, least work reduces to the minimum least work of separation: the true exergetic value of the product and a useful benchmark for evaluating energetic efficiency of separation processes. All separation processes are subject to these energy requirements; several cases relevant to established and emerging desalination technologies are considered. The effect of nonidealities in electrolyte solutions on least work is analyzed through comparing the ideal solution approximation, Debye-HĂĽckel theory, Pitzer's ionic interaction model, and Pitzer-Kim's model for mixed electrolytes. Error introduced by using incorrect property models is quantified. Least work is a strong function of ionic composition; therefore, standard property databases should not be used for solutions of different or unknown composition. Second Law efficiency for chemical separation processes is defined using the minimum least work and characterizes energetic efficiency. A methodology is shown for evaluating Second Law efficiency based on primary energy inputs. Additionally, entropy generation mechanisms common in desalination processes are analyzed to illustrate the effect of irreversibility. Formulations for these mechanisms are applied to six desalination systems and primary sources of loss are identified. An economics-based Second Law efficiency is defined by analogy to the energetic parameter. Because real-world systems are constrained by economic factors, a performance parameter based on both energetics and economics is useful. By converting all thermodynamic quantities to economic quantities, the cost of irreversibilities can be compared to other economic factors including capital and operating expenses. By applying these methodologies and results, one can properly characterize the energetic performance and thermodynamic irreversibilities of chemical separation processes, make better decisions during technology selection and design of new systems, and critically evaluate claimed performance improvements of novel systems.by Karan H. Mistry.Ph.D
Effect of entropy generation on the performance of humidification-dehumidification desalination cycles
This paper applies irreversibility analysis to characterize humidification-dehumidification (HD) desalination cycles and to identify how to further improve cycles and components. It is shown that minimizing specific entropy generation of the cycle maximizes the gained output ratio (GOR). It is also shown that each cycle has one limiting component that cannot be substantially improved and a second component that should be the target of efforts to minimize entropy generation. Finally, the failure of exergy analysis to yield conclusive results for on-design HD cycle analysis is discussed briefly.Center for Clean Water and Clean Energy at MIT and KFUP
An improved model for multiple effect distillation
Increasing global demand for fresh water is driving research and development of advanced desalination technologies. As a result, a detailed model of multiple effect distillation (MED) is developed that is flexible, simple to implement, and suitable for use in optimization of water and power cogeneration systems. The MED system is modeled in a modular method in which each of the subcomponents is modeled individually and then instantiated as necessary in order to piece together the complete plant model. Modular development allows for studying various MED configurations (such as forward feed, parallel feed, etc.) with minimal code duplication. Use of equation-oriented solvers, such as Engineering Equation Solver and JACOBIAN, rather than sequential solvers, simplifies the coding complexity dramatically and also reduces the number of required approximations and assumptions. The developed model is compared with four prominent forward feed MED models from literature. Through parametric analysis, it is found that the present model compares very well with the simple model provided by El-Sayed and Silver while providing substantially more detail in regard to the various temperature profiles within the MED system. Further, the model is easier to implement than the detailed El-Dessouky model while relying on fewer assumptions. The increased detail of the model allows for proper sensitivities to key variables related to input, operating, and design conditions necessary for use in a cogeneration or hybrid system optimization process.Center for Clean Water and Clean Energy at MIT and KFUPM (Project R13-CW-10
Association of facet orientation and tropism with lumbar disc herniation
Background: Intervertebral disc herniation is a degenerative lumbar disease and a common pathology of skeletal system. Currently, most experts assume that facet tropism may affect lumbar degenerative diseases. Considering the previous inconsistent findings on the relationship of facet tropism, the present study was aimed to find the association between facet tropism and lumbar disc herniation.Methods: Patients with low back pain attending the OPD of orthopaedics department, with signs and symptoms of disc herniation were sent for magnetic resonance imaging (MRI). 72 patients with single level disc herniation were included in the study. Facet angles were measured using MRI of 1.5 T using the method described by Karacan et al. Facet tropism was defined as difference of 100 or more in facet joint angles between right and left sides.Results: 45 of the 72 cases (50%) who presented with lumbar disc herniation (LDH) had tropism while none (0%) at the control level did. This association was not statistically significant (p=0.983). Significant association was found between the side of disc herniation and the distribution of the more coronal or sagittal facing facet (p=0.024).Conclusions: Despite the presence of tropism only in the intervertebral segments affected with LDH in our study, the association between tropism and LDH was not statistically significant
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