Is income inequality persistent? Evidence using panel stationarity tests, 1870-2011

Using data on inequality for 21 OECD countries over the period 1870-2011 this paper tests the Piketty hypothesis that income inequality is likely to grow in the 21st century. It is shown that the null hypothesis of trend stationarity of inequality cannot be rejected at conventional significance levels, suggesting that shocks to income inequality are likely to be temporary

Transformer-less local grid based 11 kV SCHB multilevel converter for renewable energy systems

Due to the variable nature of renewable energy resources and power demand by the consumers, it is difficult to operate a power system installed with only one type of renewable energy resource. The local grid based renewable generation may be the only solution to overcome this problem. In this regard, an 11 kV Series Connected H-Bridge (SCHB) multilevel Voltage Source Converter (VSC) is proposed, which is the transformer less, cost effective solution to interface the renewable generation system to the local grid directly. This paper presents the design, simulation and analysis of a Five Level (5L)-SCHB and an Eleven Level (11L)-SCHB VSC for an 11 kV local grid based renewable energy systems. The performance, cost, modulation scheme and harmonic spectra of the converter are the bases for analysis. © 2011 IEEE

Performance and cost comparison of NPC, FC and SCHB multilevel converter topologies for high-voltage applications

The rapid increase in global energy consumption and the impact of greenhouse gas emissions have accelerated the renewable energy technology into a more competitive area. Due to the variable nature of renewable energy resources and power demand by the consumers, grid based renewable generation has gained significant popularity in the world. High-voltage converter can interconnect the renewable systems to the grid directly without introducing a lossy, costly and bulky transformer. Three popular multilevel converter topologies: Neutral Point Clamped (NPC), Flying Capacitor (FC) and Series Connected H-Bridge (SCHB) have successfully made their way into the industry and therefore can be considered a mature and proven technology for low and medium voltage applications. But most of them are not suitable for high-voltage applications. This paper presents the comparison of a Five-Level (5L)-NPC, a 5L-FC, a 5L-SCHB, an Eleven-Level (11L)-NPC, an 11L-FC and an 11L-SCHB topologies for an 11 kV Voltage Source Converter (VSC). The comparison is made in terms of number of semiconductors, semiconductor cost, Total Harmonic Distortion (THD), filter size and control complexity. © 2011 IEEE

Small scale integrated agriculture: a tool of poverty alleviation, gender equality promotion and improving food security at household level in coastal region of Bangladesh

The chemical composition of four edible plant foods species, three fish species and one prawn were analyzed in Food Chemistry Laboratory of Behbahan Khatam Alanbia University of Technology, Behbahan, Iran in 2014. The analysis of fatty acid and sugars composition were performed by gas liquid chromatography and high performance liquid chromatography, respectively. Protein and lipid content were founded higher in baked and fried in fish S. commersonnianus (74.29%), (20.20%), fish Sphyraena helleri (88.12%) and (17.77%), respectively. Ash content in fish S. commersonnianus varies from 9.80% to 15.34%, and in fish S. helleri from 5.83% to 7.68%. Based on the proximate analysis, it can be calculated that an edible portion of 100 g of studied edible plant foods provides, on average, around 303.9±1.04 kcal. The plant Portulaca neglecta is suitable for high temperature food processes. The macronutrient profile in general revealed that the wild plant foods were with rich sources of protein and carbohydrates, and had low amounts of fat. The highest protein, the lowest fat and energy contents were found in boiled in both fish species; therefore, boiling can be recommended as the best cooking method for healthy diet.Int. J. Agril. Res. Innov. & Tech. 5 (2): 82-85, December, 201

A multilevel medium-voltage inverter for step-up-transformer-less grid connection of photovoltaic power plants

Recently, medium (0.1-5 MW) and large (>5 MW) scale photovoltaic (PV) power plants have attracted great attention, where medium-voltage grid connection (typically 6-36 kV) is essential for efficient power transmission and distribution. A power frequency transformer operated at 50 or 60 Hz is generally used to step up the traditional inverter's low output voltage (usually ≤400 V) to the medium-voltage level. Because of the heavy weight and large size of the power frequency transformer, the PV inverter system can be expensive and complex for installation and maintenance. As an alternative approach to achieve a compact and lightweight direct grid connection, this paper proposes a three-phase medium-voltage PV inverter system. The 11-kV and 33-kV PV inverter systems are designed. A scaled down three-phase 1.2-kV test rig has been constructed to validate the proposed PV inverter. The experimental results are analyzed and discussed, taking into account the switching schemes and filter circuits. The experimental results demonstrate the excellent feature of the proposed PV inverter system. © 2011-2012 IEEE

Morphological characterization and genetic diversity in lentil (Lens culinaris medikus ssp. Culinaris) germplasm

Genetic divergence of 110 lentil germplasm with checks was assessed based on morphological traits using multivariate analysis. Mahalanobis generalized distance (D2) analysis was used to group the lentil genotypes. Significant variations among lentil genotypes were observed in respect of days to 1st flowering, days to 50% flowering, days to maturity, plant height, and number of pods per peduncle, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant. Considering the mean values, the germplasm were grouped into ten clusters. The highest number of genotypes (17) was in cluster X and lowest (5) both in cluster II and IV. Cluster IV had the highest cluster mean for number of pods per plant (297.08), number of seeds per plant (594.16), 100 seed weight (1.44 g) and yield per plant (8.53 g). Among them, the highest inter-cluster distance was obtained between the cluster IV and I (24.61) followed by IV and III (22.33), while the lowest was between IX and II (1.63). The maximum value of inter-cluster distance indicated that genotypes belonging to cluster IV were far diverged from those of cluster I. The first female flower initiation was earlier in BD-3812 (49 days) in cluster I and cluster IV had highest grain yield per plant (8.53). BD-3807 produced significant maximum number of pods per plant (298.40) in cluster IV. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21095 Int. J. Agril. Res. Innov. & Tech. 4 (1): 70-76, June, 201

Affinity purification of hen egg lysozyme using sephadex G75

We found lysozyme binds Sephadex G75, a dextran-based matrix routinely used for Gel-filtration chromatography, in a pH dependent manner. The binding is rapid and specific in a buffer containing 25 mM NaCl at pH 8.0, and requires only 0.1 ml of swollen Sephadex G75 suspension per mg of lysozyme. The bound lysozyme can be eluted with NaCl concentration over 0.15 M in the same buffer in a relatively pure form. Exploiting these binding properties with Sephadex G75, chromatographic and scaled-up methods were optimized to purify lysozyme from hen eggs with over 80% yield and over 70- fold purification. This also allows faster isolation of lysozyme compared to current methods in use

Modular Medium-Voltage Grid-Connected Converter with Improved Switching Techniques for Solar Photovoltaic Systems

© 1982-2012 IEEE. The high-frequency common magnetic-link made of amorphous material, as a replacement for common dc-link, has been gaining considerable interest for the development of solar photovoltaic medium-voltage converters. Even though the common magnetic-link can almost maintain identical voltages at the secondary terminals, the power conversion system loses its modularity. Moreover, the development of high-capacity high-frequency inverter and power limit of the common magnetic-link due to leakage inductance are the main challenging issues. In this regard, a new concept of identical modular magnetic-links is proposed for high-power transmission and isolation between the low and the high voltage sides. Third harmonic injected sixty degree bus clamping pulse width modulation and third harmonic injected thirty degree bus clamping pulse width modulation techniques are proposed which show better frequency spectra as well as reduced switching loss. In this paper, precise loss estimation method is used to calculate switching and conduction losses of a modular multilevel cascaded converter. To ensure the feasibility of the new concepts, a reduced size of 5 kVA rating, three-phase, five-level, 1.2 kV converter is designed with two 2.5 kVA identical high-frequency magnetic-links using Metglas magnetic alloy-based cores

Optimal design of high-frequency magnetic links for power converters used in grid-connected renewable energy systems

© 2014 IEEE. Recently high-frequency common magnetic links with cores of advanced magnetic materials, such as nanocrystalline and amorphous materials, have been considered as viable candidates for the development of medium-voltage power converters. This offers a new route of step-up-transformer-less compact and lightweight direct grid integration of renewable generation systems. Most importantly, it minimizes the voltage imbalance and common mode issues of the converter systems. However, the electromagnetic design of high-frequency common magnetic links is a multiphysics problem and thereby affects the system efficiency and cost. In this paper, an optimization technique is proposed and verified by prototype magnetic links. The design optimization, implementation, test platform, and experimental test results are analyzed and discussed

Design and comparison of 11 kV multilevel voltage source converters for local grid based renewable energy systems

Because the availability of renewable energy is highly variable and the power demand by the consumers could have a very different characteristic, it is very desirable to connect a renewable generation system to the grid. In this respect, the 11 kV multilevel Voltage Source Converter (VSC) has no heavy transformer and is the cost effective solution to interfacing a renewable generation system to the local grid directly. This paper presents the design and comparison of a Five-Level Neutral Point Clamped (5L-NPC), a Five-Level Flying Capacitor (5L-FC), a Five-Level Series Connected H-Bridge (5L-SCHB), an Eleven-Level Neutral Point Clamped (11L-NPC), an Eleven-Level Flying Capacitor (11L-FC), and an Eleven-Level Series Connected H-Bridge (5L-SCHB) VSC for an 11 kV local grid based converter. The cost of power semiconductors and capacitors, modulation schemes and harmonic spectra of the converters are the bases for comparison. © 2011 IEEE