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A known policy dilemma occurs between the need to curb extra-large profits by some industries, like pharmaceuticals, and the need to ensure the incentive to produce is not damaged. This paper shows that a profit cap, imposed via taxation on a group of firms, can simultaneously eliminate inefficiency and excess profit by intensifying competition among oligopolistic firms. The result has a direct bearing on policy debates on COVID-19 vaccine sharing and the use of vaccine donation as a "humanitarian obligation," and, more generally, on the regulatory institutions needed for industries that rely on R&D. [ABSTRACT FROM AUTHOR]

Linear modulation techniques (LMTs) of an asymmetrical six-phase machine (ASPM) with two isolated neutral points synthesize the desired voltage vectors by applying at least five switching states. Different choices of applied voltage vectors, sequences in which they are used, distribution of dwell-times among the redundant switching states give rise to a large number of possible LMTs. It is desirable that these LMTs avoid more than two transitions of a particular inverter leg within a carrier period. Only a subset of existing LMTs of ASPM follows this rule. Through an innovative approach, this article finds a way to account for all possible infinitely many LMTs that follow the rule of at most two transitions per leg. Another important criterion for the selection of an LMT is its current-ripple performance. Therefore, through numerical optimization, this article finds optimal LMTs among the above infinite possible LMTs for all reference voltage vectors in the linear range and for the whole feasible range of a machine parameter. This parameter is related to the leakage inductance of the machine and impacts the current ripple performance of ASPM. An optimal hybrid strategy is proposed with these optimal techniques, which outperforms all existing techniques in terms of the current ripple. The theoretical analysis is validated through simulation in MATLAB and experiments performed up to 3.5 kW on a hardware prototype. [ABSTRACT FROM AUTHOR]

Fast switching transient of SiC mosfet reduces switching loss. However, it excites device and circuit parasitics resulting in prolonged oscillation, high device stress, spurious turn on, EMI related issues, and higher switching loss. Behavioral or analytical models are used to estimate switching loss $(dv/dt)$ , $(di/dt)$ rates, etc., and it requires the value of circuit parasitics as input. Measurement is the only way to accurately estimate some device package-dependent circuit parasitics when the internal package geometry is unknown. Hence, measurement of circuit parasitic is essential for optimal design. This article presents a set of simple experimental measurement techniques to determine circuit parasitic inductance and capacitances relevant for switching transient study of SiC mosfet in a half-bridge configuration. The accuracy of the proposed technique is verified through simulation and experimental results of the hard turn offand capacitor assisted soft turn-off dynamics of SiC mosfet over a range of operating conditions for two 1.2-kV discrete SiC mosfet of different current ratings and two different PCB layouts. Furthermore, the proposed technique is also validated with the existing frequency response analysis-based impedance measurement. [ABSTRACT FROM AUTHOR]

Introduction: In view of the present Coronavirus Disease 2019 (COVID-19) pandemic it is of utmost importance to look out for the 'trojan horse' that is the asymptomatic population who are potential for spreading the disease. Healthcare Workers (HCWs) are the most vulnerable group. The possibility of having the infection does not always correlate well with the symptoms. It urges the need for development of certain special plans beyond continuous surveillance and symptom monitoring. Aim: To explore asymptomatic COVID-19 infection among HCWs as a potential source of transmission. Materials and Methods: This hospital-based cross-sectional study was conducted at Medical College and Hospital, Kolkata, West Bengal, India, from June 2020 to September 2020. The data were collected from 714 HCWs over a period of three months of study period, with the help of a standard questionnaire and blood sample was analysed by serological assessment of Immunoglobulin G (IgG) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by EUROIMMUN Kit, Enzyme-Linked Immunosorbent Assay (ELISA). Epi info software 7, available from the World Health Organisation (WHO) site was used to manage and analyse the data. Results: The mean age was 35.30±11.79 years. Out of 714 people, 54.8% (391/714) were male and 45.2% (323/714) were female. In this survey, 9.16% of HCWs in COVID-19 designated duties were IgG positive; whereas 21.89% of HCWs designated in other parts of area were detected to be IgG positive. Seroprevalence was least amongst nursing staffs with 5.41% (8/148); among doctor's it was 9.62% (41/426). Most interestingly among ward boys and cleaners this prevalence was found to be 29.90% (29/97) being the highest. Overall seroprevalence for IgG against SARS-CoV-2 was found to be 12.75% (91/714). Conclusion: This serosurvey at this tertiary COVID-19 care facility is a unique venture to look for the possible sources of super-spread. The high rate of sero-positivity among ward boys and cleaners might be due to their lack of knowledge and training regarding steps to prevent a droplet borne pandemic. This study also points out that if adequate precautions are taken, infectivity is not to an alarming extent, even in a fullfledged COVID-19 care hospital. [ABSTRACT FROM AUTHOR]

This article presents a systematic design procedure for a dual-active-bridge (DAB) dc–dc converter. Design of a DAB converter involves determination of two key parameters, i.e., transformer turns ratio and the series inductance value. Existing literature addresses this problem through numerical optimization, which is computation intensive and does not provide much insight. In general, loss is minimized by applying equal weightage to all operating conditions, which may not be practical. Given an operating power range, terminal voltage range, and switching frequency, this article presents a way to optimally select the design variables through analytical solution of a constrained optimization problem. Analysis is carried out in the time domain, and an optimal triple-phase-shift modulation strategy is considered that ensures minimum inductor rms current and soft switching. The choice of the design parameters results in minimization of the worst-case inductor rms current over the entire operating range of the converter, which leads to both efficiency and size optimization. A procedure for selection of devices and filter capacitors and design of magnetics is given. A 2.6-kW experimental prototype is designed to validate the theoretical analysis. [ABSTRACT FROM AUTHOR]

Switching transients of SiC MOSFET are fast compared to its Si counterpart. Fast switching transient reduces switching loss but may induce prolonged oscillations, spurious turn-on, high device stress, and electromagnetic interference (EMI)-related issues, etc. In soft switched converters, use of external drain source capacitance can reduce these adverse effects along with the reduction in switching loss. However, the selection of external drain source capacitance is not straightforward. A large external capacitance reduces switching loss, $(dv/dt)$ , $(di/dt),$ and transient over-voltage but may also result in higher dead-time loss and reduced switching frequency. This article presents an analytical model that captures the soft turn-off switching dynamics of SiC MOSFET using parameters obtained from device datasheet along with the values of external circuit parasitics. Unlike linear approximation, a nonlinear channel current model is used along with a comprehensive model of transfer capacitance. The effect of external gate drain capacitance is also considered. This leads to a better estimation of switching transition time, actual loss, $(dv/dt)$ , $(di/dt)$ , and transient over voltage. Also, a method to select an optimal value of external drain source capacitance is presented. The proposed model is validated through behavioral simulation and experiment for two 1.2-kV discrete SiC MOSFETs. [ABSTRACT FROM AUTHOR]

Overmodulation techniques of asymmetrical six-phase machine achieve higher dc-bus utilization by applying voltage in the nonenergy transfer plane. This results into unwanted current and associated copper loss. Existing overmodulation technique minimizes this voltage from space-vector perspective with predefined set of four active vectors. To find the best technique, one needs to perform the above minimization problem with all possible sets of active vectors with which higher voltage gain can be attained. Therefore, this requires evaluation of large number of cases. This article formulates the above minimization problem in terms of average voltage vectors of two three-phase inverters, where active vectors need not to be specified beforehand and, thus, the analysis is more general. Sixteen possible techniques with different set of active vectors are derived following the above analysis, which attain minimum voltage injection in the nonenergy transfer plane. This article also identifies one of these 16 techniques, which can be implemented without involving complex six-dimensional transformation. The above technique is validated through experiments on six-phase induction motor and simulations in MATLAB at 3.5-kW power level. [ABSTRACT FROM AUTHOR]

Overmodulation (OVM) techniques of asymmetrical six-phase induction machine (ASIM) achieve higher dc-bus utilization by applying nonzero average voltage in nonenergy transfer plane. This results into unwanted current and associated copper loss. Existing OVM techniques reduce this loss with pulsewidth modulation (PWM) techniques from six-dimensional space vector perspective, which is both conceptually difficult and computationally challenging. The computational complexity of space vector based techniques is reduced by few existing PWM techniques in linear region by splitting the six-phase inverter as two three-phase inverters and modulate these inverters with linear PWM techniques in 30 $^\circ$ phase shifted. This is referred as three-phase inverter based technique in the title. But, three-phase inverter based OVM technique does not exist in the literature due to lack of knowledge of the relationship between six-dimensional space vectors and space vectors of two three-phase inverters. This article first establishes this relation. Based on this relation, an OVM technique is proposed where the reference voltage vectors of two inverters are phase shifted by 30 $^\circ$ but of different magnitudes. The proposed technique achieves THD and WTHD performances similar to space vector based best technique of ASIM with reduced computational complexity, as shown in details. The proposed strategy is validated through experiments and simulations on six-phase induction machine at 4.2 kW. [ABSTRACT FROM AUTHOR]

Fast switching transient of SiC mosfet may lead to prolonged oscillations, spurious turn on, large device stress, and high amount of electromagnetic interference generation. For an optimal layout and gate driver design, study of switching dynamics is important. This article presents an analytical model that captures the turn-off switching dynamics of SiC mosfet and SiC Schottky barrier diode (SBD) pair using parameters obtained from device and gate driver datasheets and the values of external circuit parasitics. Unlike linear approximation, a detailed model of channel current is considered that captures the gradual transition from ohmic to saturation region and the transverse electric field effect. A comprehensive model of the transfer capacitance is used and the effect of external gate-drain capacitance is considered. This results in a better estimation of switching transition time, actual loss incurred, (dv/dt), (di/dt), and transient overvoltage. The behavioral simulation and experimental results confirm the accuracy of the presented analytical model over a range of operating conditions for two 1.2-kV discrete SiC mosfet and SBD pairs of different current ratings. [ABSTRACT FROM AUTHOR]

A three-level three-phase single-stage high-frequency link dc–ac converter is reported in this article for grid integration of photovoltaic sources. The proposed topology employs two three-level neutral point clamp (NPC) half-bridge legs on the dc side. The advantages of using three-level legs over conventional two level are: 1) the three-level legs can be implemented with the devices with lower blocking voltage which are economical; and 2) the low voltage blocking devices have lower on-state drop and lower turn on–off energy losses compared to high voltage blocking devices used in a two-level leg. These help to improve the converter efficiency. The sinusoidal pulsewidth modulation is implemented with the three-level NPC legs. The modulation strategy ensures reduced neutral current drawn by the NPC legs. The inner switches of the NPC legs are zero voltage switched. The turn-on transitions of the outer switches are with zero current. The proposed solution employs two high-frequency transformers to provide galvanic isolation which results in compact, low cost isolated converter solution. The intermediate dc link is pulsating and does not require any filtering. A low-frequency unfolder is employed to generate line frequency ac from pulsating dc. The switching loss of the unfolder is negligible. The proposed topology can support stand-alone load up to $\pm 0.866$ PF. The converter operation is verified on a 2-kW hardware prototype. [ABSTRACT FROM AUTHOR]

In this article, a pulsewidth modulated single-stage high frequency link three-phase dc–ac converter is proposed for grid integration of solar and fuel cell-based energy sources. On the dc side, the converter has three half-bridge legs which are zero-voltage switched over the entire line cycle without using any additional snubber circuit. On the ac side, two diode bridge rectifiers and one neutral point clamped (NPC) T-type three-level inverter are employed. The active switches in NPC inverter are switched either at line frequency or twice of it, incurring negligible switching loss. Modulation ensures soft commutation in the diode bridges. The intermediate three-level dc bus is pulsating and does not require any dc-filter capacitor and thus reduces overall filtering requirements. The high frequency galvanic isolation provides high power density, low-cost converter solution. The converter operation is analyzed in detail and verified on a 2-kW hardware prototype. [ABSTRACT FROM AUTHOR]

Hardware emulators, simulating a test environment in real time, are an essential tool in testing power system equipment. This article presents a hardware emulator of a programmable transmission line capable of simulating high-frequency transients. Emulation of, energization of long transmission line, requires the observer to solve transmission line or telegraphers equations in real time. This article identifies a continuous time model that captures the wave nature and suitable for real-time implementation. This article derives the discrete-time model to be solved in the observer of the hardware emulator. A step-by-step procedure is given to determine two key emulator parameters: observer sampling frequency, and switching frequency of the power amplifier considering different hardware, event, and software related constraints. For high bandwidth requirement, a high switching frequency, 100-kHz, 12-kVA silicon carbide (SiC) based voltage source converter is designed to operate under a current controller with a gain crossover frequency of 5 kHz. A system on chip that combines an Anvanced RISC Machine (ARM) processor along with an field programmable gate array (FPGA) is used to implement the observer. Experimental results verify accuracy of the designed emulator in the event of energization of a long transmission line. Though proposed transmission line emulator can only be used to study the energization of a long line with one end terminated with shunt reactor, the solution can be extended for emulation of a long line that links two sections of power grid. [ABSTRACT FROM AUTHOR]

This article proposes a unidirectional, single-stage, three-phase, and high-frequency-link dc–ac converter. The converter uses three high-frequency transformers to provide galvanic isolation. In the primary, the converter has three half-bridge legs. In the secondary, three diode-bridge rectifiers are used. Each rectifier is followed by a half-bridge (unfolder) leg. The modulation strategy proposed in this article ensures zero-voltage switching of all six primary side switches over the entire line cycle without additional snubber circuit. The secondary half-bridge legs are switched at line frequency, incurring negligible switching loss. The proposed converter does not require any interstage bulky dc-link filter capacitor. Thus, the overall filtering requirement is reduced, and the converter reliability is improved. The high-frequency galvanic isolation improves the converter power density. In this article, the modulation strategy and converter operation are described in detail. The operation is validated in a 3.7-kW hardware prototype. Key experimental results are presented in this article. [ABSTRACT FROM AUTHOR]

Alleviating poverty, mitigating inequality and achieving growth are all acknowledged goals of development, whatever the degree of success with which these goals might have been addressed in various economies of the world. Apart from questions of resolve and genuine commitment, what makes it hard to engage with these goals is that the pursuit of any one of them does not necessarily secure the ends of either or both of the other two. Such engagement requires a measure of conceptual clarity, an identification of normative priorities, and the deployment of carefully crafted policies that accommodate trade‐offs among competing goals. In particular, policies such as the single‐minded pursuit of growth as a panacea for all the difficulties of development appear to be misguided, and based on a faulty application of deductive reasoning to past experience. These issues are addressed here by attending to some elementary arithmetic revolving around the measurement of money‐metric poverty and inequality, and the decomposition of poverty changes into effects attributable to growth and distributional changes. [ABSTRACT FROM AUTHOR]

The paper provides a complete characterization of Nash equilibria for games in which n candidates choose a strategy in the form of a platform, each from a circle of feasible platforms, with the aim of maximizing the stretch of the circle from where the candidate's platform will receive support from the voters. Using this characterization, it is shown that if the sum of all players' payoffs is 1, the Nash equilibrium payoff of each player in an arbitrary Nash equilibrium must be restricted to the interval [ 1 / 2 (n - 1) , 2 / (n + 1) ]. This implies that in an election with four candidates, a candidate who is attracting less than one-sixth of the voters can do better by changing his or her strategy. [ABSTRACT FROM AUTHOR]

A novel single-stage high-frequency link three-phase ($3\phi$) inverter along with a modulation strategy is presented in this paper. The topology is targeted for grid integration of utility scale renewable and alternative energy sources like solar, fuel cell, and wind, where the power flow is unidirectional (from dc to ac). The primary side converter has a $3\phi$ voltage source inverter (VSI) structure along with an additional half-bridge leg. Sinusoidal pulsewidth modulation is implemented in the primary side converter. The three legs of the primary side VSI are zero voltage switched (ZVS) for most part of the line cycle. The additional half bridge leg is ZVS over the complete line cycle. The active switches in secondary side converter are line frequency switched and thus results in negligible switching loss. The converter switching process is described in detail to show the soft-switching of the primary side converter using the device capacitances and leakage inductances of the high-frequency transformers (HFTs). The HFT galvanic isolation results in high power density. A 4-kW laboratory scale hardware prototype is built and tested with the proposed modulation strategy. The experimental results are presented to verify the converter operation. [ABSTRACT FROM AUTHOR]

Estimation of switching loss at the early stages of design is essential for determination of switching frequency and selection of power devices. Analytical estimation similar to gate charge method results in fastest and easiest computation when compared with simulation or double pulse test based experimental approach. This paper presents an analytical estimation method of turn on switching loss of a SiC mosfet and SiC Schottky barrier diode (SBD) pair from datasheet parameters and using values of common source and dc bus inductances. Turn on losses are considered as they dominate the total switching loss. The presented method models the quadratic nature of the transfer characteristics and results in better estimation of current rise time when compared with the linear approximation used in the literature. During voltage fall, the non-linear nature of the parasitic capacitances of both the switch and the diode are considered. The simulation and experimental results confirm the accuracy of the presented method over a range of operating conditions for two 1.2-kV discrete SiC mosfet and SBD pairs of different current ratings. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses several article published within issue on topics related to entire breadth of Indian economist Amartya Sen's work—including his work in social choice theory that is not related to the capability approach to the history of ideas.

This paper presents a novel single-stage soft-switched high-frequency-link three-phase dc–ac converter topology. The topology supports unidirectional dc to ac power flow and is targeted for applications like grid integration of photovoltaic sources, fuel cell, etc. The high frequency magnetic isolation results in reduction of system volume, weight, and cost. Sine-wave pulsewidth modulation is implemented in dc-side converter. Though high-frequency switched, dc-side converter is soft switched for most part of the line cycle. The ac-side converter active switches are line frequency switched incurring negligible switching loss. The line frequency switching of ac-side converter facilitates use of high voltage blocking inherently slow semiconductor devices to generate high voltage ac output. In addition, a cascaded multilevel structure is presented in this paper for direct medium-voltage ac grid integration. A detailed circuit analysis considering nonidealities like transformer leakage and switch capacitances, is presented in this paper. A 6-kW three-phase laboratory prototype is built. The presented simulation and experimental results verify the operation of the proposed topologies. [ABSTRACT FROM AUTHOR]

The arrival of Trump in the White House does not augur well for the long-run prospects of the US economy. The protectionism that is gathering steam under his presidency may yield some short-term gains, but at the detriment of the long-run. Examining the discontent among ordinary voters that brought Trump to power, this paper argues that this should be treated as an opportunity for a major regulatory reform. With the advance of digital technology, we have increasing returns to scale, and that, in turn, is making our antitrust laws backfire and hurt the well-being of ordinary people, thereby sowing discontent. The paper builds a simple model to illustrate this and makes the case for revoking the older antitrust laws and replacing them with some simple profit-sharing rules at the level of the firm, and the economy. [ABSTRACT FROM AUTHOR]

This paper provides a new, long proof of the Pythagorean theorem. The two lemmas used should be of some intrinsic interest, especially one on isosceles triangles. [ABSTRACT FROM AUTHOR]

A solid-state transformer is a three-phase ac/ac converter with a high-frequency transformer. Due to advanced features like high power density, on demand var support and frequency regulation, solid-state transformer is an enabling technology for the modern power distribution system. It can also find application in high-power-density motor drives. The single-stage solid-state transformer considered in this paper is capable of bidirectional power flow and open loop power factor correction. This topology uses a minimum amount of copper and has relatively few semiconductor switches. One major problem in this converter is the commutation of leakage energy which results in power loss, reduction in switching frequency, loss of output voltage, and additional common-mode voltage switching. This paper presents a source-based commutation strategy along with a novel modulation technique resulting in elimination of additional snubber circuits, minimization of the frequency of leakage inductance commutation, recovery of the leakage energy, and soft switching of the output converter. The topology and its proposed control have been analyzed. Simulation and experimental results confirm the operation. [ABSTRACT FROM AUTHOR]

Pulse width modulation (PWM) converters generate switching common-mode voltages (CMVs) across the load terminals. These voltages cause common-mode currents, leading to bearing failure in motor loads and electromagnetic interference problems. This paper presents a generalized carrier-based PWM technique for open-end winding motor drives that completely eliminates switching CMV. The proposed method is applicable to both dual two-level voltage source inverter and dual matrix converter-based open-end winding drives. Detailed analysis shows that the carrier-based method requires significantly less computation compared to the corresponding space vector implementation. This paper also outlines the relationship between the two implementations. The carrier-based method is shown to achieve superior performance in terms of resource requirements and execution time when implemented on a field-programmable gate array-based real-time control platform. Simulation and experimental results have been presented to validate the proposed method. [ABSTRACT FROM AUTHOR]

A filter is required to eliminate the high-frequency switching ripple present in the input current of a matrix converter (MC). Design of such a filter requires an estimation of the higher harmonic components present in the input current. This paper presents a simple closed-form analytical expression for the RMS input current ripple injected by the MC. The expression shows the variation with load power factor and is independent of the output frequency. This is used in a step-by-step procedure to design various input filter components from the specifications of allowable total harmonic distortion in the grid current and distortion in the input voltage. The MC is modeled for the grid frequency component in order to evaluate the design for input power factor and voltage drop across the filter. A damping resistance has been designed ensuring minimum ohmic loss. The analytical estimation of the ripple current and the proposed design procedure have been validated by simulations in MATLAB/Simulink and experiments on a laboratory prototype. [ABSTRACT FROM PUBLISHER]

This paper presents a systematic step-by-step design procedure for the input filter of a current source rectifier (CSR). The design is based on the specifications of allowable ripple in the input voltage of the CSR and high-frequency harmonic components in the grid current. Analytical techniques have been developed to estimate the ripple present in the input current and to model the converter for fundamental or grid frequency. The analysis is done for carrier-based and space-vector modulation of the current source rectifier and the model at grid frequency is used to evaluate the design of the filter for grid power factor, voltage drop across filter, etc. A damping resistance is designed ensuring a minimum power loss. The analysis and design of the input filter have been verified by simulations in MATLAB/Simulink and experimental tests on a laboratory prototype. [ABSTRACT FROM AUTHOR]

This paper presents a novel topology for the generation of adjustable frequency and magnitude pulsewidth-modulated (PWM) three-phase ac from a balanced three-phase ac source with a high-frequency ac link. The proposed single-stage power electronic transformer (PET) with bidirectional power flow capability may find application in compact isolated PWM ac drives. This topology along with the proposed control has the following advantages: 1) input power factor correction; 2) common-mode voltage suppression at the load end; 3) high-quality output voltage waveform (comparable with conventional space vector PWM); and 4) minimization of output voltage loss, common-mode voltage switching, and distortion of the load current waveform due to leakage inductance commutation. A source-based commutation of currents associated with energy in leakage inductance (termed as leakage energy) has been proposed. This results in soft-switching of the output-side converter and recovery of the leakage energy. The entire topology along with the proposed control scheme has been analyzed. The simulation and experimental results verify the analysis and advantages of the proposed PET. [ABSTRACT FROM PUBLISHER]

The method of randomisation has been a major driver in the recent rise to prominence of empirical development economics. It has helped uncover patterns and facts that had earlier escaped attention. But it has also given rise to debate and controversy. This paper evaluates the method of randomisation and concludes that while the method of randomisation is the gold standard for description, and does uncover what is here called “circumstantial causality”, it is not able to demonstrate generalised causality. Nor does it, in itself, lead to policy conclusions, as is often claimed by its advocates. To get to policy conclusions requires combining the findings of randomised experiments with human intuition, which, being founded in evolution, has innate strengths. Moreover, even non-randomised empirical methods combined with reasoned intuition can help in crafting a development policy. [ABSTRACT FROM AUTHOR]

This paper presents a single-stage bidirectional high-frequency transformer (HFT) link dc/ac converter topology for a three-phase adjustable magnitude and frequency PWM ac drive. This type of converters find a wide range of applications including UPS systems, drives involving renewable energy sources (Solar, Fuel cell), and energy storage systems (typically low voltage dc to high voltage PWM ac). The HFT results in reduction in cost and weight along with a considerable increase in power density. The adverse effects of common-mode voltage are well known in this kind of applications. The proposed topology along with a modulation technique reduces common-mode voltage to practically zero and generates high-quality output voltage waveform comparable to conventional space vector PWM (CSVPWM). A source-based commutation method, presented in this paper, to commute the energy stored in the leakage inductance of the HFT resulting in the following advantages 1) no need for any auxiliary circuits with passive components; 2) almost complete recovery of the leakage energy; 3) soft switching of the output side converter for all load conditions; and 4) minimization of common-mode voltage switching due to commutation. The converter along with the suggested control has been analyzed in detail. The presented simulation and experimental results confirm the operation of the proposed converter. [ABSTRACT FROM AUTHOR]

The role of a person's group identity and sense of integration into society as a determinant of the person's productivity and capability has been vastly underestimated in the literature. We talk of policies to subsidize the poor and give direct support to alleviate poverty. These are important but, in the long run, it is critical that we instill in people a sense of belonging and having certain basic rights as citizens. This paper tries to advance this perspective by building a new model where a person's community identity matters,ex post, in determining whether he or she will be poor, even though all persons are identicalex ante. The paper also draws on data collected from a non-governmental organization-run school in Kolkata to illustrate the role of a school child's sense of ‘belonging’ in determining how the child performs academically. The theory and the empirical work are inputs into the larger and more general idea that when people feel marginalized in a society they tend to ‘give up’. A substantial part of the paper is devoted to the policy implications of these analytical ideas and empirical results in the context of policy-making. [ABSTRACT FROM AUTHOR]

Acetyl chloride is one of the most commonly available and cheap acylating agent but its high reactivity and concomitant instability in water precludes its use to carry out acetylation in aqueous medium. The present methodology illustrates the efficient acetylation of primary amines and amino acids in brine solution by means of acetyl chloride under weakly basic condition in the presence of sodium acetate and/or triethyl amine followed by trituration with aqueous saturated bicarbonate solution. This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the amide derivatives. Mechanistic rationale of this methodology is also important. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This article investigates behavior in the Traveler's Dilemma game and isolates deviations from textbook predictions caused by differences in welfare perceptions and strategic miscalculations. It presents the results of an experimental analysis based on a 2 × 2 design where the own and the other subject's bonus-penalty parameters are changed independently. We find that the change in own bonus-penalty alone entirely explains the effect on claims of a simultaneous change in one's own and the other's bonus-penalty. An increase in the other subject's bonus-penalty has a significant negative effect on claims when the own bonus-penalty is low, whereas it does not have a significant effect when the own bonus-penalty is high. We also find that expected claims are inconsistent with actual claims in the asymmetric treatments. Focusing on reported strategies, we document substantial heterogeneity and show that changes in choices across treatments are largely explained by risk aversion. [ABSTRACT FROM AUTHOR]

A voltage source inverter-fed induction motor produces a pulsating torque due to application of nonsinusoidal voltages. Torque pulsation is strongly influenced by the pulsewidth modulation (PWM) method employed. Conventional space vector PWM (CSVPWM) is known to result in less torque ripple than sine-triangle PWM. This paper aims at further reduction in the pulsating torque by employing advanced bus-clamping switching sequences, which apply an active vector twice in a subcycle. This paper proposes a hybrid PWM technique which employs such advanced bus-clamping sequences in conjunction with a conventional switching sequence. The proposed hybrid PWM technique is shown to reduce the torque ripple considerably over CSVPWM along with a marginal reduction in current ripple. [ABSTRACT FROM AUTHOR]

A pulsewidth modulation (PWM) technique is proposed for minimizing the rms torque ripple in inverter-fed induction motor drives subject to a given average switching frequency of the inverter. The proposed PWM technique is a combination of optimal continuous modulation and discontinuous modulation. The proposed technique is evaluated both theoretically as well as experimentally and is compared with well-known PWM techniques. It is shown that the proposed method reduces the rms torque ripple by about 30% at the rated speed of the motor drive, compared to conventional space vector PWM. [ABSTRACT FROM AUTHOR]

It can be argued that just as there are different kinds of literacy, there are different kinds of illiteracy. A “proximate illiterate,” i.e. an illiterate who has easy access to a literate person, is clearly better off than someone without such access. The existing literature that takes account of these differences (1) defines an illiterate person to be a proximate illiterate if he or she lives in a household with at least one literate person and (2) derives new measures of literacy which typically exceed the standard literacy rate. The latter risks generating policy complacency. The aim of this paper is to suggest a measure of literacy that is not limited by (1) and (2). The measure is axiomatically characterized and its use is illustrated with a numerical exercise for the provinces of South Africa. [ABSTRACT FROM AUTHOR]

The article discusses various papers published within the issue including one about literacy mediation and another about the need for inter-disciplinary research on the integration of practice-based model of literary in economics.

Abstract: Numerous recent investigations have revealed that various synthetic as well as therapeutically active natural flavonoids possess novel luminescence properties that can serve as highly sensitive monitors for exploring their interactions with relevant physiological targets. Here we report a detailed study on the interactions of the model flavone, 7-hydroxyflavone (7HF) with the plasma protein human serum albumin (HSA), employing electronic absorption, fluorescence (steady state and time resolved) and induced circular dichroism (ICD) spectroscopy. The spectral data indicate that in the protein matrix, the neutral 7HF molecules are predominantly transformed to a conjugate anion (7HFA) by a proton abstraction in the ground state. The protein (HSA) environment induces dramatic enhancements in the fluorescence emission intensity, anisotropy (r) and lifetime (τ) values, as well as pronounced changes in the fluorescence excitation and emission profiles of the fluorophore. Moreover, evidence for efficient Förster type resonance energy transfer (FRET, from tryptophan to 7HFA) is presented, from which we infer that the binding site of 7HF in HSA is proximal (estimated distance, R =23.6Å) to the unique tryptophan – 214 residue present in the inter-domain (between IIA and IIIA domains) loop region of the protein. The binding constant (K =9.44×104 M−1) and the Gibbs free energy change (ΔG =−28.33kJ/mol) for 7HFA–HSA interaction have been estimated from the emission data. Finally, the near-UV circular dichroism (CD) studies show that the electronic transitions of 7HF are strongly perturbed on binding to the chiral host (HSA), leading to the appearance of ICD bands. Implications of these results are discussed. [Copyright &y& Elsevier]

Abstract: We have studied the confinement of robinetin, a therapeutically active plant flavonol, in cyclodextrin (CDx) nanocavities, using steady state and time resolved fluorescence spectroscopy. Enhanced tautomer emission (arising from excited state intramolecular proton transfer (ESIPT)) as well as dramatically blue shifted (∼10nm in β-CDx and ∼33nm in SHP β-CDx) normal fluorescence observed upon addition of the β-CDxs indicate that robinetin readily enters the doughnut-shaped hydrophobic cavity of β-CDx where the chromone moiety is well shielded from external hydrogen bonding perturbations. Detailed analyses of the fluorescence data (emission profile, anisotropy, decay times) indicate that robinetin forms 1:1 inclusion complexes with both natural and chemically modified β-cyclodextrins (β-CDx and SHP β-CDx) with affinity constant values K =195±17M−1 and 1055±48M−1 respectively, indicating the prospective utility of SHP β-CDx in particular as an effective drug carrier. Unlike β-CDxs, α-CDxs do not form inclusion complexes with robinetin. To further characterize the robinetin/β-CDxs complexes, circular dichroism (CD) spectroscopic studies have been performed, which reveal that incorporation of robinetin molecules in the chiral environment of the β-CDxs strongly affects the electronic transitions of robinetin leading to the occurrence of positive induced circular dichroism (ICD) bands in the near ultra-violet (UV) region. Molecular mechanics calculations show that the inclusion complex with the chromone ring inserted into the β-CDx cavity is most favorable, in agreement with our spectroscopic data. [Copyright &y& Elsevier]

It is a widely accepted principle of economics that if two or more adults voluntarily agree to a contract or an exchange that has no negative fall-out on others, then the government should not stop such a contract. This is often called the ‘principle of free contract’ (PFC). There is a body of writing in economics which upholds the PFC. Yet this ubiquitous principle is ill-defined and full of ambiguities. For instance, since it refers to voluntary choice, its proper use presumes an understanding of what is ‘voluntary’ and, therefore, also, of what is coercive. What is ironic is that, while philosophers and legal scholars have debated and analyzed these concepts and the validity of the principle of free contract, there is very little discussion of these in economics, even though so much of economics is founded on this principle. This has caused a lot of policy confusion. The aim of this paper is to construct general rules for when we may violate the PFC. The argument is constructed within the Paretian framework. Hence, the violation of the PFC is not justified by appeal to deontological ethics or non-welfarist criteria. This is not an easy task since the principle of free contract is often viewed as a rule that is a derivative of the Pareto principle. [ABSTRACT FROM AUTHOR]

Summary: The paper studies the relation between globalization, inequality, and marginalization, within and across countries. It reviews the existing evidence on globalization and global inequality and argues, using a simple theoretical model, that the two are inter-connected. It discusses alternative policies to counter extreme poverty and inequality. The paper takes the view that curbing these, even within one country, requires global, cross-country policies that we do not currently have, and advocates the setting up of an international initiative to coordinate such policies. [Copyright &y& Elsevier]

The article presents the author's comments on how the effectiveness of International Labor Standards (ILS), an initiative aimed at promoting better working conditions and higher living standards in developing countries, can be enhanced. The author opines that the UN Global Compact is better than ILS. According to him, any ILS effort can be successful if it takes into account opinions of developing countries. The author also discusses global democracy.

Analyzes a landlord and a tenant as two players making non-cooperative decisions regarding the terms of their respective contracts with a tenant. Circumstances in which interlinkage is superior; Moral hazard; Incorporation of risk aversion; Changes in the superiority of claims.

Focuses on some plausible spillover effects that would weaken arguments in favor of food for relief programs. Differential effects in prices of paying wages in food and cash; Impact of a cash-for-work program.

A power electronic converter based transmission line emulator (TLE) is presented in this paper. The TLE can emulate medium and long lines in steady-state and symmetrical faults occurring at any point in the line. A traveling wave based numerical scheme for the emulation of the line is identified and then implemented on a novel digital architecture in the field-programmable gate array part of a system on chip platform. The proposed architecture meets the real-time computation constraints through parallel processing and optimal use of hardware resources (DSP slices, block RAMs, etc.). A comprehensive analysis to determine the two important parameters of the TLE—the power converter switching frequency and observer update period while satisfying a number of constraints coming from the numerical scheme, power, and embedded hardware—has been presented. Finally, relevant simulation and experimental results on a developed 400-V 15-kVA TLE prototype have been presented for validation. [ABSTRACT FROM AUTHOR]