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Purpose: The purpose of this study is to evaluate the efficacy of using endodontic H-files luted with Resin modified glass ionomer cement (RMGIC) in removing fractured palatal root. Materials and Methods: This study consists of 30 patients, of which 16 were males and 14 were females with a mean age of 36 years. In which, 19 were maxillary first molar and 11 were maxillary second molar. In that, 18 were fractured at the level of apical 1/3rd and 12 were at the level of apical 2/3rd. All cases were first tried with endodontic H-files, within few attempts, it was wedged tightly in the remaining pulp chamber with one or two clockwise direction and using sudden jerk with a downward pull the remnant part was removed. The cases, which fail to deliver after several attempts were taken up for study. After sufficient isolation with a rubber dam and the socket was dried using sterile gauze, under good lighting and vision again the same file was introduced, which was now luted with RMGIC, after 5 min of setting time, the same attempt using sudden jerk with a downward pull was given. Results: In those 30 cases, 20 cases were removed in the first few attempts using endodontic H-files. The 10 cases (7 cases were apical 2/3rd and 3 cases were of apical 1/3rd), which fails to come out were tried using endodontic H-files luted with RMGIC, in which 9 cases were successfully removed (90%) and 1 case of apical 1/3rd was again failed to come out. Conclusion: Even though, the number of cases were too small to come to a definitive conclusion, the encouraging result (90%) and technically easy, this is a novel method of removing fractured palatal root atraumatically and devoid of any complication. [ABSTRACT FROM AUTHOR]

Field experiments were conducted to study the effect of seed pelleting with flyash at different concentrations ranging from 200 to 300g per kg of seed on growth, gas exchange parameters and seed yield in sesame. Observations on growth and yield parameters viz., plant height, number of branches, number of leaves, leaf area, dry matter production, root length, root weight, number of capsules, number of seeds per capsule, 1000 seed weight, seed yield per plant and gas exchange parameters viz., net photosynthetic rate, leaf temperature, stomatal conductance and intercellular CO2 were recorded. Rhizosphere population of bacteria, fungi, actinomycetes and azospirillum were also estimated. Based on the results, it is found that sesame seeds treated with flyash @ 250 g,kg-1with rice gruel recorded the increased seed yield (Trial I - 11.867 g/plant and Trial II - 12.31 g/ plant) due to increase in growth and gas exchange parameters. [ABSTRACT FROM AUTHOR]

Identical parallel-connected converters with unequal load sharing have unequal terminal voltages. The difference in terminal voltages is more pronounced in case of back-to-back connected converters, operated in power circulation mode for the purpose of endurance tests. In this paper, a synchronous reference-frame-based analysis is presented to estimate the grid current distortion in interleaved grid-connected converters with unequal terminal voltages. Influence of carrier interleaving angle on rms grid current ripple is studied theoretically as well as experimentally. Optimum interleaving angle to minimize the rms grid current ripple is investigated for different applications of parallel converters. The applications include unity power factor rectifiers, inverters for renewable energy sources, reactive power compensators, and circulating-power test setup used for thermal testing of high-power converters. Optimum interleaving angle is shown to be a strong function of the average of the modulation indices of the two converters, irrespective of the application. The findings are verified experimentally on two parallel-connected converters, with a circulating reactive power of up to 150 kVA between them. [ABSTRACT FROM PUBLISHER]

The present study was conducted to identify rice varieties suitable for aerobic agriculture and to formulate the seed hardening and pelleting treatment that can be recommended for better crop growth and establishment under aerobic condition. The seeds of four rice varieties viz., ADT 43, ADT 38, ADT 36 and ADT 39 were treated with KCl, KH2PO4, Thiourea and CaCl2, @ 1.0 % and subsequently pelleted with pongam (Pongamia glabra) leaf powder @ 200g/kg, along with a control. The physiological parameters viz., leaf area, leaf photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, root dry weight and seed quality parameters were recorded. Among the varieties tested, ADT 43 was found more suitable for aerobic agriculture and, even though all the treatments performed better as compared to control, the seeds hardened with KCl (1%) followed by pelleting with pongam leaf powder @ 200 g kg-1 recorded higher physiological parameters and seed yield and better seed quality. [ABSTRACT FROM AUTHOR]

Before installation, a voltage source converter is usually subjected to heat-run test to verify its thermal design and performance under load. For heat-run test, the converter needs to be operated at rated voltage and rated current for a substantial length of time. Hence, such tests consume huge amount of energy in case of high-power converters. Also, the capacities of the source and loads available in the research and development (R&D) centre or the production facility could be inadequate to conduct such tests. This paper proposes a method to conduct heat-run tests on high-power, pulse width modulated (PWM) converters with low energy consumption. The experimental set-up consists of the converter under test and another converter (of similar or higher rating), both connected in parallel on the ac side and open on the dc side. Vector-control or synchronous reference frame control is employed to control the converters such that one draws certain amount of reactive power and the other supplies the same; only the system losses are drawn from the mains. The performance of the controller is validated through simulation and experiments. Experimental results, pertaining to heat-run tests on a high-power PWM converter, are presented at power levels of 25 kVA to 150 kVA. [ABSTRACT FROM AUTHOR]

Diabet. Med. 29, e308-e311 (2012) Abstract As diabetes prevalence shifts from affluent to lower-income groups in India, focus on depression in diabetes will become essential. This paper describes four perspectives through which depression and diabetes should be understood in the Indian context. We consider (1) how rapid socio-economic and demographic changes contribute to increased co-occurring diabetes and depression; (2) how social, cultural and economic factors in the Indian context contribute to depression and therefore play an important role in diabetes care; (3) biological and behavioural pathways between depression and diabetes; and (4) the role of health systems in depression, diabetes and their overlap. We conclude with recommendations for future research and policy on this topic in India. [ABSTRACT FROM AUTHOR]

Black gram is highly priced pulse, rich in protein (24%) and phosphoric acid. Besides being cooked for consumption with chepaties (rotis) and rice, it is also used in preparation of several South Indian dishes like idli, vada, dosa etc. In India, black gram is grown on an area of 2.07 million hectares with a production of 0.94 million tonnes. It is mainly grown in the States of Madhya Pradesh, Maharashtra, Uttar Pradesh, Rajasthan, Karnataka and Bihar. Seed is a biological entity. Flyash is generated during the combustion of coal in coal fired thermal power plants and paper industry. In agricultural studies, it has been reported that flyash at optimum rate can be utilized as a fertilizer. Hence, a study was formulated to elucidate information on the use of flyash seed pelleting on seed yield in blackgram. The study revealed that the flyash pelleting @ 200 g/kg-1 registered significantly higher values for plant height (cm), number of branches per plant, days to 50% flowering, number of clusters per plant, number of pods per plant, pod length, pod weight, seed weight/pod and seed yield plant-1 (g). [ABSTRACT FROM AUTHOR]

A three-level inverter produces six active vectors, each of normalized magnitudes 1, 0.866, and 0.5, besides a zero vector. The vectors of relative length 0.5 are termed pivot vectors. The three nearest voltage vectors are usually used to synthesize the reference vector. In most continuous pulsewidth-modulation (PWM) schemes, the switching sequence begins from a pivot vector and ends with the same pivot vector. Thus, the pivot vector is applied twice in a subcycle or half-carrier cycle. This paper proposes and investigates alternative switching sequences, which use the pivot vector only once but employ one of the other two vectors twice within the subcycle. The total harmonic distortion (THD) in the fundamental line current pertaining to these novel sequences is studied theoretically as well as experimentally over the whole range of modulation. Compared with centered space vector PWM, two of the proposed sequences lead to reduced THD at high modulation indices at a given average switching frequency. [ABSTRACT FROM PUBLISHER]

Special switching sequences can be employed in space-vector-based generation of pulsewidth-modulated (PWM) waveforms for voltage-source inverters. These sequences involve switching a phase twice, switching the second phase once, and clamping the third phase in a subcycle. Advanced bus-clamping PWM (ABCPWM) techniques have been proposed recently that employ such switching sequences. This letter studies the spectral properties of the waveforms produced by these PWM techniques. Further, analytical closed-form expressions are derived for the total rms harmonic distortion due to these techniques. It is shown that the ABCPWM techniques lead to lower distortion than conventional space vector PWM and discontinuous PWM at higher modulation indexes. The findings are validated on a 2.2-kW constant V/ƒ induction motor drive and also on a 100-kW motor drive. [ABSTRACT FROM AUTHOR]

Abstract: The recent quest to replace fossil fuels with renewable and sustainable energy sources has increased interest on utilization of landfill and bio gases. It is further augmented due to environment concerns and global warming caused by burning of conventional fossil fuels, energy security concerns and high cost of crude oil, and renewable nature of these gases. The main portion of landfill gas or biogas is comprised of methane and carbon dioxide with some other gases in small proportions. Methane if released directly to the atmosphere causes about 21 times global warming effects than carbon dioxide. Thus landfill gas is generally flared, where the energy recovery is not in place in practice. Using landfill gas to generate energy not only encourages more efficient collection reducing emissions into the atmosphere but also generates revenues for operators and local governments. However, use of landfill gases for energy production is not always perceived as an attractive option because of some disadvantages. Thus it becomes necessary to address these disadvantages involved by studying landfill gases in a technological perspective and motivate utilization of landfill gas for future energy needs. This paper discussed landfill gas as a fuel for a spark ignition engine to produce power in an effective way. It has been shown that though the performance and combustion characteristics of the landfill gas fueled engine deteriorated in comparison with methane operation, increasing compression ratio and advancing spark timing improved the performance of the landfill gas operation in par with methane operation. The effects due to composition changes in the landfill gas were found more pronounced at lean and rich mixture operation than at stoichiometry. In addition, the effects of additions of hydrogen up to 30% in the landfill gas were studied. Addition of even small quantities of hydrogen such as 3–5% delivered better performance improvement particularly at the lean and rich limit operations and extended the operational limits. Additions of hydrogen also improved the combustion characteristics and reduced cyclic variations of landfill gas operations especially at the lean and rich mixtures. [Copyright &y& Elsevier]

A single-phase boost rectifier system with conventional low-bandwidth voltage loop exhibits poor dynamic response. A simple method is presented to improve the dynamic response of the rectifier without affecting its steady-state performance. A fast voltage controller is used to improve the dynamic response of the rectifier. The increased low-frequency ripple at the output of the voltage controller is filtered out using a new filter. Design methodology for the voltage loop is presented. The filter is simple enough for analog and digital implementations. Low input current distortion, fast voltage-loop response, and improved dynamic response against line and load disturbances are demonstrated experimentally on a 300-W digitally controlled boost rectifier operating at a switching frequency of 100 kHz. [ABSTRACT FROM AUTHOR]

This paper investigates certain novel switching sequences involving division of active vector time for space vector-based pulsewidth modulation (PWM) generation for a voltage source inverter. This paper proposes two new sequences, and identifies all possible sequences, which result in the same average switching frequency as conventional space vector PWM (CSVPWM) at a given sampling frequency. This paper brings out a method for designing hybrid PWM techniques involving multiple sequences to reduce line current ripple. The three proposed hybrid PWM techniques (three-zone PWM, five-zone PWM and seven-zone PWM) employ three, five and seven different sequences, respectively, in every sector. Each sequence is employed in a spatial region within the sector where it results in the lowest rms current ripple over the given sampling period. The proposed techniques lead to a significant reduction in THD over CSVPWM at high line voltages. The five-zone technique results in the lowest THD among real-time techniques with uniform sampling, while the seven-zone technique is the best among real-time techniques with twin sampling rates. The superior harmonic performance of the proposed techniques over CSVPWM and existing bus-clamping PWM techniques is established theoretically as well as experimentally. [ABSTRACT FROM AUTHOR]

This paper presents the analysis, design, and control of a four-wire rectifier system using split-capacitor topology. The proposed controller does not require any complex transformation or input voltage sensing. A detailed analysis of the distortions in the line and the neutral currents is presented. It is shown that the single-carrier-based, conventional sine-triangle PWM (CSPWM) scheme results in a peak-to-peak neutral current ripple, which is greater than the peak-to-peak ripple of any of the line currents. Also, for the same operating condition, the distortions in the line and the neutral currents increase considerably, when a three-limb boost inductor is used instead of three single-phase inductors. A three-carrier-based SPWM scheme is proposed in this paper. Compared to CSPWM, the proposed scheme significantly reduces the neutral current ripple when three single-phase inductors are used, and reduces both line and neutral current ripples when a three-limb inductor is used. The control scheme is verified through Matlab simulation. It is implemented on an field-programmable gate-array (FPGA)-based digital controller and tested on a proto-type. Simulation and experimental results are presented. [ABSTRACT FROM AUTHOR]

This paper presents a generalized feedforward control scheme for a single-phase boost rectifier, operating with in-direct current control, to improve the dynamic response of its output voltage against line and load disturbances, as well as for changes in the reference voltage. Digital implementation of the control method is discussed. A small-signal model of the converter system is presented. The stability of the current loop at light loads is studied. A method is presented to estimate the input voltage and the load current without having to actually measure these quantities for the purpose of feedforward control. Simulation and experimental results are presented. [ABSTRACT FROM AUTHOR]

Converters operated in discontinuous-conduction-mode (DCM) and in continuous-conduction-mode (CCM) are suitable for lighter and higher loads, respectively. A new, constant switching frequency based single-phase rectifier system is proposed, which operates in DCM and in CCM for outputs less than and greater than 50% rated load, respectively, covering a wide range of load variation. The power circuit and the control circuit of the proposed rectifier are easily configurable for DCM and CCM operations. The measured load current is used to select the desired operating mode. The peak device current under DCM is limited to rated device current under CCM without using a device of higher current rating. The input current shaping under CCM and DCM are based on the comparison of measured input current with linear and nonlinear carriers, respectively. A load current feedforward scheme is presented to improve the system dynamic performance and also to ensure a smooth transition between the two operating modes. All the necessary control operations are performed without using multiplication, division and square-root operation. The proposed rectifier shows improved input current characteristics over the existing CCM converters for the above load range. This is validated on a 600-W rectifier prototype. Simulation and experimental results are presented. [ABSTRACT FROM AUTHOR]

The objective of the present work is to improve the output waveform of three level inverters used in high-power applications, where the switching frequency is very low. This is achieved by maintaining the synchronization, half-wave symmetry, quarter-wave symmetry, and three-phase symmetry in the pulsewidth modulation (PWM) waveforms. The principles of achieving synchronization and symmetries in terms of space vectors for three level inverters are presented. A novel synchronized space vector pulsewidth modulation (SVPWM) algorithms is proposed and verified experimentally. The experimental wave- forms of the inverter output voltage and motor no load current for different operating conditions of the drive are presented. The performance measure in terms of the weighted total harmonic distortion (THD) of the line voltage is computed for the linear modulation region of the drive for the proposed algorithm and compared with that of synchronized SVPWM and synchronized sine-triangle pulsewidth modulation (SPWM) technique. The comparative results show that consideration of synchronization and symmetry results in improved THD. Another significant feature of the proposed algorithm is that the symmetry and synchronization leads to self-balancing of the direct current (dc) bus capacitor voltages over every one third cycle of the fundamental. [ABSTRACT FROM AUTHOR]

A simple analog controller is proposed for the single-phase half-bridge pulsewidth modulation rectifier to maintain near unity power factor at the input and balance the voltages across each half of the dc bus. The controller works in the principle of constant-frequency current programmed control. The required gating pulses are generated by comparing the input current with a linear and bipolar carrier without sensing the input voltage. Two voltage controllers and a single reset-integrator are used to generate the carrier. All the necessary control operations are performed without using any phase locked loop, multiplier, and/or divider circuits. Resistor based sensors are used to measure the voltages across two halves of the dc bus and the input current. The controller can be fabricated as a single integrated circuit. The averaged small signal models and all the necessary design equations are provided. The condition of stability against subharmonic oscillation is analyzed. Calculation of switching and conduction losses is presented. The control concept is validated through simulation and also experimentally on an 800-W half-bridge rectifier. Experimental results are presented for ac-dc application, and also for ac-dc-ac application with both linear and nonlinear loads at two different output fundamental frequencies (50 and 60 Hz). [ABSTRACT FROM AUTHOR]

Conventional space vector pulsewidth modulation (CSVPWM) employs conventional switching sequence, which divides the zero vector time equally between the two zero states in every subcycle. Existing bus-clamping PWM (BCPWM) techniques employ clamping sequences, which use only one zero state in a subcycle. This paper deals with a special type of switching sequences, termed here as ‘double-switching clamping sequences,’ which use only one zero state and apply an active vector twice in a subcycle. The present work brings out a class of bus-clamping PWM techniques, which employ such sequences. It is shown analytically as well as experimentally that the proposed BCPWM techniques result in reduced harmonic distortion in the line currents over CSVPWM as well as existing BCPWM techniques at high modulation indices for a given average switching frequency of FSW. At high modulation indices, the dominant harmonic components in the line voltages are around 2 FSW with the proposed BCPWM techniques, while the dominant components are around FSW and 1.5 FSW, respectively, with CSVPWM and existing BCPWM techniques. The proposed techniques also reduce the inverter switching losses at high power factors over CSVPWM and existing BCPWM techniques. [ABSTRACT FROM AUTHOR]

This paper presents a method to evaluate harmonic distortion due to space vector-based pulse-width modulation (PWM) strategies for ac drives. The proposed method is general enough to deal with division of zero vector time as well as division of active vector time within a subcycle. The method is based on the notion of stator flux ripple, which is a measure of line current ripple. Expressions for RMS ripple over a subcycle are derived for six switching sequences in terms of magnitude and angle of the reference vector, and subcycle duration. The sequences considered include those involving division of active vector time within a subcycle. Further, analytical closed form expressions are derived for the total RMS harmonic distortion factor corresponding to six space vector-based synchronized PWM strategies, proposed recently, for high power drives. The square of the distortion factor turns out to be a quadratic polynomial in modulation index (M), and the coefficients differ with PWM, strategies and pulse numbers. These expressions are validated through Fourier analysis as well as experimental measurements. The concept of stator flux ripple provides insight into current ripple as well as torque ripple corresponding to different sequences and strategies. [ABSTRACT FROM AUTHOR]

Investigates the operation of four space vector-based synchronized pulse-width modulation (PWM) strategies in the overmodulation zone using three different overmodulation algorithms. Previous discussions on the overmodulation in PWM voltage source inverters; Strategies for space vector-based synchronized; Discussion on the results of the study.

Proposes two synchronized, bus-clamping pulse width modulation (PWM) strategies based on the space vector approach. Conditions for waveform symmetries; Rules that can be generalized to any sectors; Basic bus clamping strategy; Different zones of modulation.

Aim: The aim of this study is to evaluate the efficacy of a single piece bird wing osteotectomy segment during anterior maxillary osteotomy (AMO) markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method thereby reducing the kinking effect to the palatal pedicle and gives good perfusion to the anterior segment. Materials and Methods: This study was conducted at Karpaga Vinayaga Institute of Dental Sciences composing of 20 patients in which male: female ratio was 8:12, with a mean age of 25-30 years. This bird wing segment technique is performed following presurgical orthodontics under the guidance of clinical assessment of the gummy smile with an incisal show when the lip is at repose (vertical maxillary excess), especially for the calculated amount of superior repositioning. It is calculated by subtracting 2 mm from the total amount of an incisor show when the lip is at repose. The normal incisal show when the lip is at repose is 2 mm. After conventional primary AMO cut was performed, the precise calculated. Results: All our cases were tested positive for pulp vitality, no relapse, and minimal edema and with no changes in the bite or dentoalveolar relation followed until 1 year postoperatively indicating a good perfusion to the anterior segment and all the patients were satisfied esthetically and free of complaints. Conclusion: This simple technique allows the precise amount of calculated bone removal in a single piece from the nasal floor markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method there by reducing the kinking effect to the palatal pedicle and maintains good perfusion. [ABSTRACT FROM AUTHOR]

Advanced Therapy Medicinal Products (ATMPs), that include gene and cell therapy products, belong to a rapidly developing and state-of-the-art field of science and technology. Due to their complex nature, product development can be challenging. While they are being regulated under the same principle as for all medicinal products, that is where the similarity ends. From start to finish, these products need a personalised approach which considers 1. The scientific complexity 2. The regulatory expectations 3. The reimbursement challenges While a conventional medicinal product such as a small molecule or even a biological product could follow a stepwise approach to achieve success in development, regulatory approval and commercialisation and reimbursement, such an approach for cell and gene therapies might not be efficient and appropriate. Further, the scientific model of drug development starting from quality/ CMC through to non-clinical and clinical development to achieve licensing may be inefficient at best and misleading at worst. To ensure that the right steps are taken for development, there are a number of regulatory procedures available. One such procedure is scientific advice from regulatory agencies. It is strongnly recommended to consider this as early as possible. This can also include joint advice with both regulatory agencies and payers to ensure that both are taken into account for planning the development. Thus, the ATMP development program should aim to streamline development and avoid known pitfalls in order to produce a viable product that will fulfil its potential in the real-world setting. For this reason, an integrated approach that includes involvement of all the stakeholders from beginning to end is needed if these products with their enormous potential including curing a complex and devastating condition are to achieve their full potential to the patients with serious and unmet medical need and who are ultimately the real beneficiaries. [ABSTRACT FROM AUTHOR]

Background: Black gram is one of the important pulse crops of the world and India is the major producer and consumer of pulses in the world. One of the main reason for low productivity of pulses is that they are cultivated mostly in areas with low soil moisture and poor soil fertility. In order to overcome such adverse conditions, low-cost techniques like seed hardening/pelleting are preferred. Seed pelleting provides package of nutrients that influences seed or soil at the seed-soil interface. Since the cost involved is very less, an attempt has been made to study the effect of botanical seed pelleting and foliar spary on growth and yield parameters in black gram cv. CO 6. Methods: Field experiments were conducted to evaluate the cumulative effect of botanical seed pelleting with pungam leaf powder @ 150g kg-1 and foliar spray of prosopis and moringa leaf powders with different concentrations (2%, 4%, 6% and 8%) on morpho physiological, leaf chlorophyll, gas exchange and yield parameters in black gram cv. CO 6 in the study. The observations on morpho physiological, leaf chlorophyll, gas exchange and yield parameters were recorded, statistically analysed and discussed here. Result: From the results, it was found that among the treatments, seed pelleting with pungam leaf powder @ 150 g kg-1 + foliar spray of prosopis leaf powder @ 6% recorded higher morpho physiological parameters viz., plant height (48.73 cm), number of branches plant-1 (8.78), dry matter production (14.83 g plant-1), chlorophyll 'a' (1.03 mg g-1), chlorophyll 'b' (1.11 mg g-1) and total chlorophyll content (2.14 mg g-1), photosynthesis and transpiration rates (27.33 mg CO2 m-2 s-1 and 10.60 mg H2O m-2 s-1), intercellular CO2 concentration and stomatal conductance (274.30 µ mol mol-1 and 0.82 mol-2s-1). This treatment also recorded lower number of days to first flowering (23.23 days), earliness in 50 per cent flowering (30.12 days) and also recorded higher yield parameters such as lengthier pods, more number of pods plant-1, pod yield plant-1, number of seeds pod-1, seed yield plant-1, seed yield ha-1 and hundred seed weight of 5.60 cm, 26.30, 8.20 g, 7.30, 5.30 g, 795.12 kg ha-1 and 5.83 g, respectively as compared to other treatments. To conclude, seed pelleting with pungam leaf powder @ 150 g kg-1 + foliar spray of prosopis leaf powder @ 6% proved to be the best in enhancing morpho physiological, growth and yield parameters. [ABSTRACT FROM AUTHOR]

Cluster bean is one of the major legumes cultivated in many parts of the world. However effect of organic seed pelleting in this crops needs more attention nowadays in probem soils like saline soil. Field experiments were carried out with cluster bean cv. Pusa Mausami to study the effect of organic seed pelleting on biometric, biophysical and yield parameters of clusterbean under saline condition. The seeds of cluster bean cv. Pusa Mausami were pelleted with pungam, prosopis, notchi, arappu leaf powders @ 50, 100, 150 and 200 g per kg. From the results, it was found that seed pelleting with pungam leaf powder @ 200 g per kg registered significantly higher values for biometric parameters viz., plant height, number of branches per plant, dry matter production, biophysical parameters viz., photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration and yield parameters viz., pod length, number of pods per plant, pod yield per plant, number of seeds per pod, seed yield per plant and hundred seed weight. From the present study, it was concluded that seed pelleting with pungamn leaf powder @ 200 g per kg can be recommended for increased growth and yield parameters in cluster bean under saline conditions. [ABSTRACT FROM AUTHOR]

A conventional input-voltage sensor-based vector-controlled PWM rectifier is used in wide range of applications due to its well-known control structure, simple design, and good dynamic performance. Many existing input voltage sensorless methods have a control structure significantly different from that of conventional vector control, involving additional computational and design efforts. This article proposes a simplified input voltage sensorless control which has the same control structure as that of vector control and can utilize similar controller design procedure. The input voltage required for a phase-locked loop (PLL) is estimated from the current controller output using a simple algebraic equation. The sensorless PLL, so obtained, is mathematically modeled, and its frequency response is shown to be similar to that of a sensor-based PLL. The performance of the proposed method is compared with those of existing methods in terms of input power factor, response to distorted input voltage, sensitivity to system parameter, and computation time requirement through simulations and experiments. Apart from having the lowest computation requirement, the proposed method is shown to achieve the sensorless operation without any performance degradation, compared to the sensor-based operation, and with robustness to parameter variation. The proposed method includes a start-up procedure, which ensures low starting transient current. [ABSTRACT FROM AUTHOR]

Seed pelleting with leaf powders of two botanicals viz., pungam (Pongamia glabra) and prosopis (Prosopis juliflora) was done to study the effect of botanical seed pelleting on seedling quality, gas exchange, growth, yield and resultant seed quality parameters of black gram in the laboratory and field. From the results, it was found that, seeds pelleted with pungam leaf powder @ 150 g kg-1 recorded higher germination percentage (93.00), root length (18.35 cm), shoot length (19.34 cm), dry matter production (0.48 mg seedling-10) and vigour index (3505.10). The yield parameters such as pod length, number of pods plant-1, pod yield plant-1, number of seeds pod-1 and 100 seed weight were also found higher in pungam leaf powder pelleting treatment @ 150 g kg-1. The control recorded the least values in all these growth and yield parameters of black gram. [ABSTRACT FROM AUTHOR]

• Cotyledonary leaves, shoot tips, hypocotyls and nodes were used to accomplish regeneration methods in Spermacoce hispida. • High frequency plant regeneration through organogenesis and somatic embryogenesis was achieved from nodal segments. • Hypocotyl-derived calli were induced shoot regeneration on MS medium containing kinetin. • Survival rate of successfully accomplished plantlets was evaluated under greenhouse and at filed conditions. • Histological evidences confirmed the regeneration mode through organogenesis and somatic embryogenesis. Shaggy button weed (Spermacoce hispida L.) is a therapeutically important herb widely used in Indian System of medicine particularly Ayurvedic, Siddha, and Unani. S. hispida is recalcitrant during germination in natural habitat. Plant tissue culture is an alternate approach for mass multiplication of such vulnerable plants. Plant regeneration by organogenesis and somatic embryogenesis in S. hispida was attempted using cotyledonary leaf, shoot tip, hypocotyl, and nodal explants. Maximum shoot regeneration frequency (72%) and number of shoots (10.5 ± 0.3) through direct organogenesis was achieved from nodal explants cultured on Murashige and Skoog (MS) medium amended with 2.0 mg/dm3 of 6-benzylaminopurine (BAP). Further, MS medium containing 0.5 mg/dm3 2, 4-dichlorophenoxyacetic acid (2, 4-D) produced higher frequency of callus induction (86.25%) from hypocotyl segments. Optimum shoot regeneration response (69.5%) through indirect organogenesis was observed from hypocotyl-derived callus on MS medium fortified with 1.0 mg/dm3 kinetin with 6.1 shoots per callus. The highest regeneration frequency (68%) through somatic embryogenesis was recorded from nodal explants on MS medium supplemented with 2.0 mg/dm3 BAP and 0.8 mg/dm3 kinetin. The regenerated plantlets were acclimatized successfully under ex vitro conditions with normal phenotypic appearance. Shoot tips and nodes did not induce organogenesis (indirect), whereas nodal segments showed better regeneration via organogenesis (direct) and somatic embryogenesis in MS medium with either BAP or BAP with kinetin. Histological examinations confirmed the distinctive developmental stages and bipolar structure of somatic embryos. The described regeneration protocols can be effectively utilized for the large-scale multiplication, germplasm conservation, pharmacological and genetic manipulation studies. [ABSTRACT FROM AUTHOR]

A response by A.C. Binojkumar et al. to a letter to the editor about their article "A variable switching frequency PWM technique for induction motor drive to spread acoustic noise spectrum with reduced current ripple," published in a previous issue of the journal is presented.

The allylboration of mono-, di- and trifluorobenzaldehydes (II) with (E)-methyl 3-phenyl-2-(pinacolylmethyl)acrylate (I) yields cis-γ-fluorophenyl-α-methylene-β-phenyl-lactones (III). [ABSTRACT FROM AUTHOR]

High-performance industrial drives widely employ induction motors with position sensorless vector control (SLVC). The state-of-the-art SLVC is first reviewed in this paper. An improved design procedure for current and flux controllers is proposed for SLVC drives when the inverter delay is significant. The speed controller design in such a drive is highly sensitive to the mechanical parameters of the induction motor. These mechanical parameters change with the load coupled. This paper proposes a method to experimentally determine the moment of inertia and mechanical time constant of the induction motor drive along with the load driven. The proposed method is based on acceleration and deceleration of the motor under constant torque, which is achieved using a sensorless vector-controlled drive itself. Experimental results from a 5-hp induction motor drive are presented. [ABSTRACT FROM AUTHOR]

The acoustic noise emitted by an induction motor powered by a voltage source inverter (VSI) is an environmental issue. Harmonics present in the stator current are the main reason for the increased acoustic noise in motor drives. The pulse-width modulation (PWM) technique used to modulate the inverter is a key factor in determining the magnitude of current harmonics. Bus-clamping PWM (BCPWM) techniques have got much attention nowadays due to reduced switching loss, compared with conventional space vector PWM (CSVPWM). In this paper, two BCPWM techniques, namely $60^\circ$ and $30^\circ$ BCPWM methods are compared with CSVPWM on the basis of electrical spectra as well as acoustic noise spectra. Experiments are conducted on a pulse-width-modulated VSI-fed induction motor drives. Harmonic analysis is carried out on the measured line-to-line voltage, stator current, and acoustic noise corresponding to the three methods at different fundamental and carrier frequencies. Based on the magnitude and phase of current harmonics, the frequency and normalized magnitude of dominant magnetic force waves are predicted theoretically. Theoretical predictions and experimental results both show that the magnitudes of dominant acoustic noise components around the carrier frequency are reduced significantly with these BCPWM methods compared with CSVPWM. Furthermore, it is shown that $30^\circ$ BCPWM is better than $60^\circ$ BCPWM in terms of acoustic pleasantness. [ABSTRACT FROM PUBLISHER]

A correction to the article "Control of Three-Phase, Four-Wire PWM Rectifier" that was published in the previous issue is presented.

The Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts project aims to identify a population of extremely luminous galaxies using the Planck all-sky survey and to explore the nature of their gas fuelling, induced starburst, and the resulting feedback that shape their evolution. Here, we report the identification of 22 high-redshift luminous dusty star-forming galaxies (DSFGs) at z  = 1.1–3.3 drawn from a candidate list constructed using the Planck Catalogue of Compact Sources and Wide-field Infrared Survey Explorer all-sky survey. They are confirmed through follow-up dust continuum imaging and CO spectroscopy using AzTEC and the Redshift Search Receiver on the Large Millimeter Telescope Alfonso Serrano. Their apparent infrared luminosities span (0.1–3.1) × 1014 L⊙ (median of 1.2 × 1014 L⊙), making them some of the most luminous galaxies found so far. They are also some of the rarest objects in the sky with a source density of ≲0.01 deg−2. Our Atacama Large Millimeter/submillimeter Array 1.1 mm continuum observations with θ ≈ 0.4 arcsec resolution show clear ring or arc morphologies characteristic of strong lensing. Their lensing-corrected luminosity of L IR ≳ 1013 L⊙ (star-formation rate ≳ 103 M⊙ yr−1) indicates that they are the magnified versions of the most intrinsically luminous DSFGs found at these redshifts. Our spectral energy distribution analysis finds little detectable active galactic nucleus (AGN) activity despite their enormous luminosity, and any AGN activity present must be extremely heavily obscured. [ABSTRACT FROM AUTHOR]

Submergence tolerance is an important character to be considered when flash flood damages rice. Tolerant genotypes can withstand submergence for 1-2 weeks based on their tolerance level. Hence with a view to study the effect of submergence on germination and seedling attributes, eight cultivated varieties were subjected to submergence tolerance at five levels of flooding viz., 1 cm, 2 cm, 3 cm, 4 cm and 5 cm flooding levels. CR 1009 sub 1, a submergence tolerant variety was used as check. With increase in submergence levels, greater reduction was observed for all the parameters. Survival % and seedling length were found to be decreased under flooded conditions, but to a much lower extent in the tolerant genotype. Flooding decreased shoot, root and total dry matter production in all the varieties with more reduction in higher flooding (5 cm) rather than lower flooding (1cm) levels. [ABSTRACT FROM AUTHOR]

Oilseeds occupy the prime position next to cereals on crop map of India and had golden age between the late eighties and early nineties. In last two decades, all the oilseeds except soyabean experienced negative growth in area led to stagnant or decreasing domestic production of oilseeds in the country.Consequently, today India is importing more than half of its annual edible oils demand which is driven by the ever increasing population and urbanization over the period of time. To become self-sufficient, either it is required to improve the national oilseeds productivity or shift to better alternative crops with higher oil content like palm (4 ton ha-1). The present study offers the meaningful insights into the changing oilseeds and edible oils scenario in India. [ABSTRACT FROM AUTHOR]

This paper presents an experimental procedure to determine the acoustic and vibration behavior of an inverter-fed induction motor based on measurements of the current spectrum, acoustic noise spectrum, overall noise in dB, and overall A-weighted noise in dBA. Measurements are carried out on space-vector modulated 8-hp and 3-hp induction motor drives over a range of carrier frequencies at different modulation frequencies. The experimental data help to distinguish between regions of high and low acoustic noise levels. The measurements also bring out the impact of carrier frequency on the acoustic noise. The sensitivity of the overall noise to carrier frequency is indicative of the relative dominance of the high-frequency electromagnetic noise over mechanical and aerodynamic components of noise. Based on the measured current and acoustic noise spectra, the ratio of dynamic deflection on the stator surface to the product of fundamental and harmonic current amplitudes is obtained at each operating point. The variation of this ratio of deflection to current product with carrier frequency indicates the resonant frequency clearly and also gives a measure of the amplification of vibration at frequencies close to the resonant frequency. This ratio is useful to predict the magnitude of acoustic noise corresponding to significant time-harmonic currents flowing in the stator winding. [ABSTRACT FROM PUBLISHER]

The ac-side terminal voltages of parallel-connected converters are different if the line reactive drops of the individual converters are different. This could result either from differences in per-phase inductances or from differences in the line currents of the converters. In such cases, the modulating signals are different for the converters. Hence, the common-mode (CM) voltages for the converters, injected by conventional space vector pulsewidth modulation (CSVPWM) to increase dc-bus utilization, are different. Consequently, significant low-frequency zero-sequence circulating currents result. This paper proposes a new modulation method for parallel-connected converters with unequal terminal voltages. This method does not cause low-frequency zero-sequence circulating currents and is comparable with CSVPWM in terms of dc-bus utilization and device power loss. Experimental results are presented at a power level of 150 kVA from a circulating-power test setup, where the differences in converter terminal voltages are quite significant. [ABSTRACT FROM PUBLISHER]

This article reports design and testing of silicon carbide) devices-based three-phase asymmetric H-bridge converter capable of switching at 50 kHz and intended to drive high-speed switched reluctance machine. Electromagnetic designs of a 7.5-kW, 30 000-r/min and a 20-kW, 50 000-r/min Switched reluctance machine are presented. The 30 000-r/min machine is fabricated and characterized. A machine model is obtained from the measured characteristics. Based on the machine model, as well as drive operating variables and device data-sheet parameters, two methods are proposed for evaluating the losses in the power devices. The first method relies on machine model to obtain machine current and converter duty ratio, and thereby estimate the device losses. A second simplified method provides closed-form expressions for device losses. The proposed analytical expressions relate the machine characteristics such as inductance and saturation current with converter losses. The estimated loss is further used to predict device junction temperature. The power converter and device ratings are chosen so that the converter is suitable for both machines. The capacitor selection and sizing are discussed. Further, the power converter architecture and other subsystems of the converter are described. Test results are presented for the asymmetric H-bridge converter at 800 V dc bus voltage, 50 A of load current, and 50 kHz of switching frequency. Thermal image is presented for validation of estimated heat-sink temperature. The predicted heat-sink temperature is found to agree well with the measured temperature. The power converter is used to operate the 30 000-r/min machine at various speeds. [ABSTRACT FROM AUTHOR]

The equivalence of triangle-comparison-based pulse width modulation (TCPWM) and space vector based PWM (SVPWM) during linear modulation is well-known. This paper analyses triangle-comparison based PWM techniques (TCPWM) such as sine-triangle PWM (SPWM) and common-mode voltage injection PWM during overmodulation from a space vector point of view. The average voltage vector produced by TCPWM during overmodulation is studied in the stationary (a-b) reference frame. This is compared and contrasted with the average voltage vector corresponding to the well-known standard two-zone algorithm for space vector modulated inverters. It is shown that the two-zone overmodulation algorithm itself can be derived from the variation of average voltage vector with TCPWM. The average voltage vector is further studied in a synchronously revolving (d-q) reference frame. The RMS value of low-order voltage ripple can be estimated, and can be used to compare harmonic distortion due to different PWM methods during overmodulation. The measured values of the total harmonic distortion (THD) in the line currents are presented at various fundamental frequencies. The relative values of measured current THD pertaining to different PWM methods tally with those of analytically evaluated RMS voltage ripple. [ABSTRACT FROM AUTHOR]

Voltage source inverters (VSIs) supply nonsinusoidal voltages to induction motor drives, leading to line current distortion and torque pulsation. Conventional space vector pulsewidth modulation (PWM) techniques are widely used in VSIs on the account of good waveform quality and high dc bus utilization. In a conventional space vector PWM technique, the switching sequence begins with one zero state and ends with the other zero state in a subcycle. Some novel switching sequences have been proposed, which employ only one zero state but apply one of the two active states twice in a subcycle. One pair of such special switching sequences has recently been shown to reduce the pulsating torque considerably. In this paper, the conventional and special switching sequences are compared experimentally in terms of acoustic noise. In the low- and medium-speed ranges, the special switching sequence is seen to reduce the amplitude of the tonal component of noise at the switching frequency considerably and is also found to result in spread spectrum. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Pixantrone dimaleate (pixantrone)-a novel aza-anthracenedione-was synthesised to reduce anthracycline-related cardiotoxicity without compromising antitumour efficacy. We aimed to assess the efficacy and safety of pixantrone versus an investigator's choice of a single-agent therapy in heavily pretreated patients with relapsed or refractory aggressive non-Hodgkin lymphoma. METHODS: In this phase 3, multicentre, open-label, randomised trial at 66 hospitals in Europe, India, Russia, South America, the UK, and the USA, patients with histologically confirmed aggressive non-Hodgkin lymphoma who had relapsed after two or more previous chemotherapy regimens were randomly assigned (1:1) by an interactive voice response system to treatment with pixantrone dimaleate (85 mg/m(2) intravenously on days 1, 8, and 15 of a 28-day cycle, for up to six cycles) or to a comparator (vinorelbine, oxaliplatin, ifosfamide, etoposide, mitoxantrone, or gemcitabine) given at prespecified standard doses and schedules. Patients were stratified by region, International Prognostic Index score, and previous stem-cell transplantation. Patients and investigators were not masked to treatment assignment; however, an independent assessment panel was masked. The primary endpoint was the proportion of patients with a complete or unconfirmed complete response in the intention-to-treat (ITT) population at the end of treatment. Primary analyses of efficacy were based on the independent assessment panel's data review. The study is registered at ClinicalTrials.gov, number NCT00088530. FINDINGS: The ITT population comprised 70 patients randomly assigned to the pixantrone group and 70 to the comparator. Five patients (two in the pixantrone group and three in the comparator group) dropped out before receiving their study drug. 14 patients (20·0% [95% CI 11·4-31·3]) who received pixantrone achieved a complete or unconfirmed complete response at end of treatment compared with four patients (5·7% [1·6-14·0]) in the comparator group (p = 0·021). The most common grade 3 or 4 adverse events in patients given pixantrone were uncomplicated, non-cumulative neutropenia (28 [41·2%] of 68 patients vs 13 [19·4%] of 67 patients in the comparator group), leucopenia (16 [23·5%] vs five [7·5%]), and thrombocytopenia (eight [11·8%] vs seven [10·4%]). INTERPRETATION: Pixantrone, given as a single-agent salvage therapy in heavily pretreated patients with relapsed or refractory aggressive non-Hodgkin lymphoma, is efficacious and tolerable. It could be a treatment option for patients whose aggressive non-Hodgkin lymphoma has failed to respond to at least two previous chemotherapy regimens. FUNDING: Cell Therapeutics, Inc. [ABSTRACT FROM AUTHOR]

Abstract: A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) were synthesized via allylboration and screened against three human pancreatic cancer cell lines (Panc-1, MIA PaCa-2, and BxPC-3). This systematic study established a discernible relationship between the substitution pattern of AMGBL and their anti-proliferative activity. β,γ-diaryl-AMGBLs, particularly those with a trans-relationship exhibited higher potency than parthenolide and LC-1 against all three cell lines. [Copyright &y& Elsevier]