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Sustainable development is the ultimate focus for all the upcoming inventions and innovations in the modern world. Automotive manufacturers contribute their research in terms of producing eco-friendly vehicles since it is proven that internal combustion engine–powered vehicles directly affect the air quality with their polluting exhaust gas. The rapid emergence of zero tailpipe emission vehicles such as electric and fuel cell electric vehicles (FCEVs) obtained the attention of major automotive giants worldwide. owing to their green mobility, battery-operated electric vehicles have already hit the road despite the challenges of recharging time, availability of recharging stations, range-to-weight ratio, and battery life and its recycling process. Drastic upscaling research and development of hydrogen FCEVs paves the way to reach the goal of sustainable transportation with its air cleaning effect, long range, zero tailpipe emission, and quick refueling time. FCEVs run with the help of hydrogen and atmospheric oxygen leaving only pure water and warm air as an exhaust. The efficiency of a proton exchange membrane fuel cell (PEMFC) in FCEVs depends on various internal and external parameters. Research and development in terms of internal parameters with respect to the internal components of a fuel cell stack includes proper fuel and airflow channel design, efficient design of thin gas diffusion layer (GDL), and self-humidifying membrane structure design. On the other hand, the external parameters such as maintaining temperature, pressure and humidity of inlet hydrogen and air and its flow rate, and proper hydrogen recirculating system. In this article, considering the practical limitations of our fuel cell stack, we have considered only external parameters of oxygen concentration and temperature of the fuel cell stack for our experimentation. We did the experiment with oxygen cylinders and concluded that fuel cell stack efficiency increases with the increase in oxygen concentration from 21% to 50%. Also, we concluded that by maintaining the optimum temperature of the fuel cell stack with a variable flow coolant pump, maximum efficiency is retained in the temperature range of 40–55°C.

Transition metal ion (Mn2+) doped BiFeO3 (BiFe0.95Mn0.05O3) nanoparticles were synthesized by low temperature polymer assisted hydrothermal method. The core/shell BiFe0.95Mn0.05O3@SiO2 nanocomposite was prepared using Stober method. X-ray diffraction patterns with rietveld analysis confirm a FeO6 octahedron distorted rhombohedral structure. The formation of amorphous silica shell was ensured through the observance of a broad hump in the XRD pattern, FESEM and HRTEM microstructures and UV–Vis studies. The particles with an average size of 127 nm were found to be agglomerated and covered with a silica layer of approximately 10–12 nm. The energy band gaps (Eg) were determined from the diffused reflectance spectra by using Tauc’s relation. It was observed that the Mn2+ doping decreased the Eg values to 1.75 eV as compared to that of 2.01 eV for pristine BFO. The optical spectrum of the nanocomposite exhibited two bandgaps, i.e 2.31 eV for BFMO and 5.1 eV for SiO2 shell. The observed 6A1g → 4T2g transition at 1.88 eV and p-d CT transitions at 3.27 eV are found to be red-shifted in comparison to pristine BFO and may be attributed to the slight disturbance in FeO6 octahedra because of Mn2+ substitution.

Among numerous heavy metals, hexavalent Chromium [Cr (VI)] place a potential threat and mostly seen in several industrial effluents such as leather tanning, printing, ceramics. For removal of Cr from waste water, reduction of Cr (VI) to Cr (III) is preferred due to less toxicity of Cr (III) than Cr (VI). Among various reduction processes, Cr (VI) reduction by photocatalysis is favoured owing to its greener approach and behaviour. Graphene nanocomposite photocatalysts show higher photo reduction efficiency due to large surface area and extraordinary electron conductance of graphene. As there is almost no resistance on the surface of graphene, so electrons move freely and faster resulting excellent surface charge transfer; therefore enhanced photocatalytic Cr (VI) reduction. We have systematically investigated the origin and enhancement of photo-reduction Cr (VI) by graphene nanocomposites photocatalysts. Graphene based metal oxides nanocomposites, metal sulphides, 0D/2D heterojunction nanocomposites, non-metallic nanocmposites, plasmonic nanocomposites and Z-scheme nanocomposites photocatalysts have been highlighted and discussed.

Abnormal uterine bleeding (AUB) is one of the commonest complaints of women in reproductive age and non-gravid state that brings them to the attention of the primary care doctor or the gynaecologist. Anovulation without any medical illness or pelvic pathology seems to be the common cause. Bleeding due to a wide variation in pathology both inside and outside the reproductive tract can be termed as anovulatory bleeding. Therefore, it is mandatory to elicit a focused menstrual history and appropriate evaluation followed by a pelvic examination. This includes a vaginal speculum examination to differentiate anovulatory bleeding from other causes of bleeding. In contrast, Heavy menstrual bleeding (HMB) is referred to as an ovulatory bleeding exceeding 8 days duration and is often caused by uterine fibroids or adenomyosis, a copper IUD or coagulation disorders. PALM-COEIN classification is a system designed by the Federation Internationale de Gynaecologie et d'Obstetrique to define the precise underlying causes of AUB. Aetiology of AUB can be classified as the following acronym "PALM-COEIN": Polyp, Adenomyosis, Leiomyoma, Malignancy and hyperplasia, Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic and Not yet classified. AUB describes a range of symptoms, such as HMB, intermenstrual bleeding (IMB) and a combination of both heavy and prolonged menstrual bleeding (MB). Dysfunctional uterine bleeding (DUB) and menorrhagia are now better described as AUB. Newborn girls sometimes spot for a few days after birth, due to placental oestrogenic stimulation of the endometrium in utero.

The debate surrounding the management of term breech presentation (BP) has resulted in the presence of a multitude of guidelines, reviews, and directives. The vaginal delivery of a breech baby requires sound obstetric skills since approximately 3-4% of babies at term are breech presentations. BP is the commonest of all malpresentations. However, expertise required to deliver breech babies vaginally has virtually disappeared. There is no convincing evidence that Caesarean Section (CS) is better than assisted vaginal delivery when conducted in appropriate settings, with experienced obstetricians and strict prevailing protocols. Unfortunately, planned vaginal breech delivery (VBD) is becoming an uncommon event. This has led to fewer opportunities for obstetric residents to master the skills of vaginal birth of breech presentations.The BP has always been a challenge for obstetricians, due to special skills required to deliver the breech safely. In addition, the immediate perinatal outcome, in terms of APGAR scores and acid-base status of the breech babies is of great concern. Thus, in 2000, in order to provide more evidence-based data, the Term Breech Trial (TBT) was published which compared the outcome of VBD with planned CS. In their 2003 Clinical Guideline, the National Institute for Health and Clinical Excellence (NICE) recommended external cephalic version (ECV) for breech presentation at 36 weeks of gestation a ns elective CS if the procedure is declined or failed. The first edition, Green-top Guidelines by the Royal College of Obstetricians and Gynaecologists (RCOG) regarding the breech delivery was first published in 1999 and revised in 2001, 2006 (Nos. 20a and 20b) and March 2017. In 2020, the Guideline Committee meeting decided on a further revision and deferred the decision for further 3 years (2023). The aim of this Guideline is to aid decision making regarding the route of delivery and choice of various techniques used during delivery. In March 2005, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) issued a formal statement concerning breech delivery at term. Through their Committee on Obstetric Practice, the American College of Obstetricians and Gynecologists (ACOG) issued a Committee Opinion paper on "Mode of term singleton breech delivery" in 2006.Almost immediately, the medical community all over the world embraced the conclusions of the trial highlighting the superiority of outcomes in planned CS compared to VBD in terms of maternal, neonatal mortality and morbidity. Clinicians, in consultation with their patients, must make the final decisions regarding mode of breech delivery in the light of the updated clinical guidelines and committee opinions for a rational choice for the mode of delivery.There is a place for planned VBD, the prerequisites are: strict case selection, operator skills and vigilant intrapartum monitoring. Provision of basic skills training by utilizing birthing pelvic models and mannikins, hands-on practice of External Cephalic Version (ECV) in clinical settings, may result in larger reduction in the risk of CS.

In this work, a layout-based FinFET design approach has been presented at 7nm technology node. Using Technology CAD (TACD) physic based tool, the electrical performances have been investigated for both n and p-channel FET. A mixed-mode integrated simulation environment has been implemented to realize the CMOS inverter for circuit applications. The signal propagation across the designed inverter has been investigated. The improvement in maximum power (P max ) performance and switching energy behavior can be observed with variation in drain voltage and fin height.

This paper presents the impact of work function variation (WFV) in Gate-All-Around Field Effect Transistors (GAA FETs) using the technology computer-aided design (TCAD) tool for sub-7nm high-performance logic applications. We have compared the WFV induced electrical characteristic variations in nanowire (NW) and nanosheet (NS) GAA FETs. We study the impacts of different grain sizes on the performance of NSFET and NWFET using statistical data analysis. The variation in critical electrical figures-of-merit (V TH , I ON , I OFF , SS, and DIBL) have been analyzed. It is predicted that the NSFET shows improved immunity toward V TH variation than NWFET. Overall, the NSFETs are less prone to performance variations compared to NWFET. As such NSFET architectures will be the preferred choice for logic devices below sub-7nm technology nodes.

At 7nm technology node, the trigate FinFETs are the promising candidates for modern integrated circuits. Their optimal design and improved performance are key demands for most of the leading semiconductor manufacturing industries. This work proposes an improvement of electrical performance through process induced stress optimization for a compressively stressed FinFET at a 7nm Technology node. The variation of two design parameters (fin angle and epi angle) can lead to a change in stress and hence the devices’ electrical performance, which is the major focus of this study. A process induced compressively stressed p-channel FinFET at 7nm Technology node is virtually fabricated using Technology CAD (TCAD) by introducing a SiGe epitaxial layer at Source and Drain regions. The variation of electrical performances with change in epi angle (θEpi) and fin angle (θFin) is critically analyzed. These results predict the improvement of the drive current and reduction in short channel effect with the appropriate selection of the θFin and θEpi. Hence, the predictive TCAD simulations explored the new avenues of strain-engineered FinFET for future CMOS technology generations.

The architecture of transistors has now switched from planar to the non-planar vertical structures. The 3-D geometry of such non-planar FinFET structures imposes new challenges especially on the computational level. Silicon channel N-type Fin shaped Field Effect Transistors (n-FinFETs) are being integrated with diamond-shaped embedded Si1−xGex fin Strain-Relaxed Buffer (SRB) to optimize the electrical performance. In this work, the stressor geometry (size and shape) effects on the device performance have been studied in detail. The mobility enhancement in n-FinFETs is observed due to process induced strain to increase the drive current. The higher percentage of Ge content shows better effect on device parameters SS, DIBL and VTH. The drain current is found to be improved for certain Ge content in the fin SRB.

Whilst COVID-19 infection generally run a mild course in up to 80% of those affected, a number of pre-existing co-morbidities determine the severity of infection and the outcome in an individual patient. The most important of these co-morbidities that have consistently emerged in studies from across the globe, are the patients age and sex. Other important co-morbidities that adversely affect outcomes include pre-existing diabetes, obesity, hypertension, chronic lung disease and malignancy. This comprehensive review discusses the impact of these co-morbidities and the role of laboratory predictors of poor patient outcomes.

Introduction and aim Dental caries is the global burden worldwide and has a negative effect on the quality of life. Restorative materials in pediatric dentistry have shown satisfactory properties; however, the highest failures are still reported due to the occurrence of secondary caries. The article aims to assess the effectiveness of pre-treatment with nano-silver fluoride (NSF) in inhibiting secondary caries at the tooth restoration interface. Materials and methods Forty tooth specimens were prepared from 20 newly extracted human premolar teeth by sectioning the tooth mesiodistally. Class V cavities were prepared on each specimen at enamel dentin junction. Specimens were randomly distributed into four groups (n=10): 1) glass ionomer cement (GIC) restoration, 2) composite restoration 3) NSF pre-treatment + GIC restoration, 4) NSF pre-treatment + composite restoration. After sterilization, specimens were subjected to artificial caries formation by pH cycling method for 14 days. Specimens were sectioned and mounted to evaluate the demineralization by using the Vickers microhardness test. Outer lesion depth was measured at the tooth restoration interface on digital radiographs. Data was analyzed using Student unpaired t-test, one-way ANOVA, and Tukey honestly significant difference (HSD) post hoc test. Results The mean microhardness value of pre-treated GIC and composite group with NSF was more than the non-treated NSF group, with a significant difference at the enamel, indicating lesser demineralization. Outer lesion depth was lesser in the pre-treated group showing better tooth restoration integrity with a statistically significant difference between the groups. Conclusion Pre-treatment with NSF is beneficial in increasing the resistance of GIC and composite resin restoration to secondary caries formation.

A comparative analysis of full electrostatic performance and RF characteristics of n-type FinFETs is carried out by using the different physical models. Quantum confinement effects are shown to be significant in sub-100 nm FinFET devices. In the simulation, the ATLAS device simulation tool is used in which various quantum corrections are implemented in models such as (Drift-Diffusion) DD, (Density-Gradient) DG, (Energy Balance) EB, and (Bohm Quantum Potential) BQP. It has been shown that the FinFETs possess the key advantages for applications in RF electronics, around ~15 GHz of transition frequency (ft) where the unilateral power gain-bandwidth product is important for the devices.

Silicon channel Nanosheet Field Effect Transistors (NSFETs) are integrated with diamond-shaped embedded-Si1−xGex source/drain (S/D) stressors to boost the electrical performance. The effects of stressor geometry (shape and size) on device performance are studied in detail. The carrier mobility enhancement due to process-induced strain in NSFET is found to increase the drain current. Further, enhancement in other electrical parameters is also obtained by increasing the Ge mole fraction in Si1−xGex. The impact of higher Ge mole fraction in the S/D region resulted in an optimum Vth, SS, and DIBL values of 141.78 mV, 69.49 mV/dec, and 24.11 mV/V, respectively. The Efficiency of S/D stress transfer is found to be dependent on the Ge mole fraction in the source/drain stressors p-channel NSFETs.

The effect of Ni doping in BiFe1−xNixO3 (BFNO) multiferroics are studied by X-ray diffraction (XRD), Fourier transmission infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), hysteresis loop (M–H), temperature dependent magnetization (FC-ZFC) measurements and electron spin resonance (ESR) techniques. The XRD and FTIR studies indicate that the BFNO compounds remain in rhombohedral (R3c) phase without appearance of any structural transformation due to Ni doping. The XPS studies show the oxidation states of Fe ions as 3+, whereas Bi is found to be in a mixed valence state of 2+ and 3+ in BFNO. The Ni ion doping enhances the saturation magnetization from 0.179 emu/g (x = 0.025) to 2.38 emu/g (x = 0.20), which is higher than the reported values found in literature. The FC-ZFC magnetization studies suggest the presence of a magnetic phase transition from a weak ferromagnetic to a spin glass state at low temperature. The ESR studies confirm the ferromagnetic state of BFNO samples.

An attempt has been made for the treatment of cyanide contaminated wastewater using a S–TiO2@rGO heterogeneous photocatalyst system immobilized on polyurethane foam (PUF) supporting materials. Further, to make the photocatalytic system more efficient and active under visible light, a highly efficient iron porphyrin derivative sensitizer viz. Fe-TCPP was synthesized and employed for cyanide degradation. To investigate the synthesized heterogeneous nano-composite S–TiO2@rGO-FeTCPP photocatalytic system, advanced techniques such as XRD, XPS, FT-IR, PL spectra, UV–vis DRS, FESEM, and EDS were utilized. The photocatalytic performance of the nanocomposite was evaluated in a suspended system and results revealed that about 75% of cyanide degradation was obtained at 100 mg/L of initial cyanide within 2 h. Whereas, at the same condition, more than 91% of cyanide degradation as well as 88% toxicity removal occurred by the PUF immobilized S–TiO2@rGO-FeTCPP solid-state photocatalytic system. First-order kinetics was applied to investigate the degradation of cyanide by the photocatalytic nanocomposite. From the kinetic study, the estimated first-order rate constant (Kf) in a solid-state photocatalytic system of the nanocomposite was 1.7 times superior to that of the suspended system. Further, the rate of photocatalytic activity was nearly 10.8 times greater than that of pure TiO2. This study demonstrated that the immobilized S–TiO2@rGO-FeTCPP photocatalytic system could be an efficient technique for degrading cyanide from industrial effluent.

This article focusses on the detailed structural and optical properties of ‘Eu’ and ‘Ni’ co-substituted Bismuth Ferrite nanoparticles synthesized using the sol-gel method. Raman analysis have confirmed the substitution induced structural distortion leading to the co-existence of Rhombohedral and Orthorhombic structures supporting the XRD and Rietveld Refinement results. Morphological studies using FESEM and HRTEM have shown irregular and inhomogeneous distribution of particles with presence of mixed phases and the elemental composition is also confirmed through EDAX analysis. The XPS analysis indicated the simultaneous presence of Fe2+and Fe3+states along with Bi3+, Eu3+ and oxygen vacancies. Thorough optical investigation using UV–Vis and PL Spectroscopy has shown an increase in absorption intensity in the visible region with a bandgap tuning from 2.17 eV to 2.12 eV in the co-substituted nanoparticles. A possible schematic energy band diagram is proposed on the basis of observed transitions in photoluminescence studies, VB-XPS analysis along with the knowledge of optical transitions in d5 systems. Photocatalytic performance of the synthesized nanostructures is studied by degradation of 2-nitrophenol. The enhanced photocatalytic response has been explained on the basis of decreased band-gap, space charge thickness and charge carrier recombination.

The use of digital technology has increased rapidly. In Indonesia, gadget use by children has become very high and requires special attention. Many effects may occur due to gadget use, one of which is sleep quality disturbance. This study aims to analyze the correlation between gadget addiction and sleep quality in children grades 4-6 SDN 01 Srigading Lawang. This research is an analytic observational study with a cross-sectional design in a population of 4-6th graders of SDN 01 Srigading Lawang. A total of 126 students over 130 students were included. Data were collected using two questionnaires, which are Smartphone Addiction Scale and The Pittsburgh Sleep Quality Index, and tested using RxC Contingency. Gadget addiction has a significant correlation with sleep quality with a weak correlation. Children with mild levels of addiction to gadgets had a potential of 2,013 times to have good sleep quality, compared to children with moderate levels of addiction. In contrast, children with severe levels of addiction to gadgets were at risk 12.04-fold to have poor sleep quality compared to the mild level of addiction. There is a significant correlation with a weak correlation between gadget addiction and sleep quality in children grades 4-6 SDN 01 Srigading Lawang.

In the present work, bismuth iron oxide-graphene composite has been explored as electrode material for electrochemical supercapacitor application. Bismuth iron oxide (BFO) nanoparticles, synthesized by sol-gel process, are mixed with the graphene sheets in a solution. The electrodes are prepared by coating the resulted slurry on stainless steel (SS) substrate, by drop casting process. The morphology and structure of the BFO-graphene composite are characterized by XRD, FIB-SEM, HRTEM and Raman spectroscopy, which show that the nanoparticles with diameter 100-200 nm are randomly distributed on and around the graphene sheets. The composite electrode exhibits significantly enhanced capacitance as compared to BFO. In this structure, the electrons generated by the surface based Faradaic reactions from the BFO nanoparticles can be transported by the graphene nanosheets toward the current collector. The electrochemical characteristic of the electrodes is investigated through cyclic voltammetry and charging/discharging process. The specific capacitance of the electrode measured at 5-100 mV/s was found to be 17-4 mF/cm(2) which is comparable to the most commonly used metal oxide based electrode materials. It shows better cycling stability with 95% retention of capacitance after 2000 cycles.

This article deals with Automatic Generation Control (AGC) of a multi area interconnected hydro thermal system in different modes using intelligent integral and proportional-integral controllers and provides the comparative analysis of electrical and mechanical governors. Appropriate Generation Rate Constraints (GRC) has been considered for the hydro and thermal generation plants. These cumulated thermal areas are considered with reheat turbines. Performances of reheat turbine mechanical governor and hydro turbine electrical governor with its dynamic responses have been investigated. Further, selection of suitable integral and proportional-integral controllers has been investigated with a Minority Charge carrier Inspired Algorithm (MCI). Cumulative system performance is examined considering with different load perturbation in both cumulative thermal areas. Further, system is investigated with different frequency bias values and results are explored.

Multiferroic bismuth ferrites (BFO) and Ni substituted bismuth ferrites (BFNO) were synthesized by standard solid state reaction route. The structural and microstructural studies were carried out. The effect of Ni substitution on dielectric constant and dielectric loss of the samples was studied in a wide range of frequency (100 Hz- 1 MHz) and temperature (27 o C – 420 o C). It has been observed that the dielectric constant increases with increase in Ni doping concentration and attained a maximum value for BFNO(x = 0.075) sample while the dielectric loss has been found to decrease with the doping concentration. This implies a reduction in the conductivity and hence improved the dielectric properties of Ni doped BFO. The anomalous peaks in temperature dependent dielectric studies indicate the increase in antiferromagnetic ordering temperature and possible existence of spin glass states upon Ni substitution in place of Fe. The complex impedance spectroscopic analysis suggests purely the intrinsic nature of the dielectric anomalies. Temperature dependent non-Debye type of dielectric relaxation has also been observed. The Nyquist plots show the negative temperature coefficient of resistance behavior of these compounds. Further it would be interesting to study their magnetic and magnetoelectric properties with the aim of identifying new multifunctional device applications. Copyright © 2014 VBRI press.

Following ultrahigh temperature granulite metamorphism at ∼1 Ga, the Eastern Ghats Province of India was intruded by the Koraput Alkaline Complex, and was subsequently re-metamorphosed in the granulite facies in the mid-Neoproterozoic time. Fluid inclusion studies were conducted on silica undersaturated alkali gabbro and syenites in the complex, and a pre-metamorphic pegmatitic granite dyke that intrudes it. High density (1.02–1.05 g/cc), pseudo-secondary pure CO2 inclusions are restricted to metamorphic garnets within the gabbro and quartz within the granite, whereas moderate (∼0.92–0.95 g/cc) and low density (∼0.75 g/cc) secondary inclusions occur in garnet, magmatic clinopyroxene, plagioclase, hornblende and quartz. The isochores calculated for high density pseudo-secondary inclusions pass very close to the peak metamorphic window (∼8 kbar, 750 °C), and are interpreted to represent the fluid present during peak metamorphism that was entrapped by the growing garnet. Microscopic round inclusions of undigested, relict calcite in garnet suggest that the CO2 present during metamorphism of the complex was internally derived through carbonate breakdown. Pure to low salinity (0.00–10.1 wt% NaCl equivalent) aqueous intra-/intergranular inclusions showing unimodal normal distribution of final ice-melting temperature (Tm) and temperature of homogenization (Th) are present only in quartz within the granite. These represent re-equilibrated inclusions within the quartz host that were entrapped at the metamorphic peak. Rare, chemically precipitated graphite along the walls of carbonic inclusions is interpreted as a post-entrapment reaction product formed during decompression. The fluid inclusion evidence is consistent with rapid exhumation of a thickened lower crust following the mid-Neoproterozoic granulite facies metamorphic event. The study suggests that mantle CO2, transported by alkaline magma into the crust, was locked up within carbonates and released during granulite metamorphism.

Cost-effective conducting polymer composite films were prepared from non-conducting polymer and black Tea. The films showed conducting and considerable magnetic properties. The measured coercive field, saturation magnetization and remnant magnetization values were found to be 80 Oe, 0.14 emu g−1 (at 8 kOe), and 9.0 × 10−3 emu g−1, respectively. In order to realize the high-frequency applications of these materials, dielectric properties were measured in the frequency range of 1 Hz–1 MHz. The measured dielectric permittivity (e') and loss tangent (tanδ) values of the composite polymer thin film were found to be 260 and 0.37 (at 1 kHz) respectively. The estimated dc conductivity (σ dc) value was around 1.60 × 10−8 S cm−1.

This paper dealt with the automatic generation control of an unequal multi-area hydrothermal system. The performance of several classical controllers such as integral (I), proportional–integral (PI), proportional–integral–derivative (PID) and integral–double derivative (IDD) are compared, and it is found that IDD controller gives better performance over the other controllers. A maiden application of Bacterial Foraging (BF) optimized fuzzy integral–double derivative (FIDD) controller has been made in the system. Comparison of the dynamic responses of the system for FIDD and IDD reveals that FIDD controller gives better dynamic performance than the later. Sensitivity analysis has been performed to find the robustness of the FIDD controller for wide change in loading. Simultaneous optimization of IDD controller gains (KI and KD) and speed regulation parameters (R) by BF technique which surprisingly has not been attempted in the past for the system provides not only the best dynamic response for the system but also provides higher values of R, that will appeal for easier and cheaper realization of the governor.

Solar panels installed over canals provide various advantages like excess power due to less temperature, reduction in the quantity of water loss due to evaporation etc. Water running in the canals also provides a source for small hydro power plants (SHP). This paper presents the control of SHP and Photo-Voltaic (PV) power of similar ratings operating together in a micro-grid. Limits imposed on hydraulic turbines due to cavitation have been considered. The SHP using synchronous machine is provided with integral controller and mechanical governor for frequency regulation in the micro-grid. The PV is maintained to operate at its maximum power. For part loading conditions, the PV is operated in de-rating mode so as to avoid operating the hydraulic turbine below manufacturer's operating limits and to maintain the desired system frequency. Non-linear models of the governor, SHP and the PV has been considered in the study.

The realisation of service oriented architecture (SOA) is embodied in the accomplishments of various simulation applicable functions in the form of service encapsulation and the interconnection and interoperation of services. In this paper, an electronic warfare (EW) simulation is structured to SOA and achieved the effect of dynamic sharing and reusability. As a proof of concept, a radar electronic support (ES) simulator, which intercepts and classifies radar signals is designed and explained in this paper. Defence Science Journal, 2012, 62(4), pp.219-222 , DOI:http://dx.doi.org/10.14429/dsj.62.929

This paper deals with automatic generation control (AGC) of a three unequal area hydrothermal system. Reheat turbines in thermal areas and electric governor in hydro area are considered. Appropriate generation rate constraints are considered in the areas. Bacterial foraging (BF) technique is used to simultaneously optimize the integral gains ( K Ii ) and speed regulation parameter ( R i ) keeping frequency bias fixed at frequency response characteristics. The integral controller in this case is termed as BFIC. The performance of a multilayer perception neural network (MLPNN) controller using reinforcement learning is evaluated for the system. In this reinforcement learning, the weights are dynamically adjusted online using backpropagation algorithm with error being the area control error (ACE). The performance of the MLPNN controller is compared with that of BFIC. Also, the performance of MLPNN controller over a wide range of system loading conditions and step load perturbations is compared with BFIC. Investigations clearly reveal the superior performance of MLPNN controller over BFIC. Sensitivity analysis subject to wide changes in system loading, inertia constant ( H ) and size and location of step load perturbation is carried out to investigate the robustness of the controller with the optimum K Ii and R i obtained at nominal condition.

This paper presents automatic generation control (AGC) of interconnected two equal area, three and five unequal-areas thermal systems provided with single reheat turbine and generation rate constraints of 3% per minute in each area. A maiden attempt is made to apply integral plus double derivative (IDD) controller in AGC. Controller gains in the two-area system are optimized using classical approach whereas in the three and five area systems controller gains and governor speed regulation parameters (Ri) are simultaneously optimized by using a more recent and powerful evolutionary computational technique called bacterial foraging (BF) technique. Investigations reveal on comparison that Integral (I), Proportional–Integral (PI), Integral–Derivative (ID), or Proportional–Integral–Derivative (PID) controllers all provide more or less same response where as Integral–Double Derivative (IDD) controller provides much better response. Sensitivity analysis reveals the robustness of the optimized IDD controller gains and Ri of the five area system to wide changes in inertia constant (H), reheat time constant (Tr), reheat coefficient (Kr), system loading condition and size and position of step-load perturbation.

A significant advance in the understanding of grain boundary contribution to magnetization in nanocrystalline ferrite thin films is demonstrated in this paper. RF-sputtered, room-temperature-deposited lithium–zinc ferrite thin films (Li 0.5− x /2 Zn x Mn 0.1 Fe 2.35− x /2 O 4 , with x =0.0, 0.16, 0.32 and 0.48) have been thermally annealed ex-situ at 850 °C and the in-plane magnetic measurements have been performed using a vibrating sample magnetometer. The percentage deviation between bulk and film magnetization ( δ M ) is observed to decrease with increasing Zn concentration, till x =0.32, and then it increases. Macro-texture measurements using X-ray orientation distribution function and micro-texture measurements using orientation imaging microscopy show reverse trend in the extent of crystallographic texturing and in the computed fraction of low-angle grain boundaries. This study brings out a correlation between low-angle grain boundary concentration and δ M .

A maiden attempt is made to examine and highlight the effective application of bacterial foraging (BF) to optimize several important parameters in automatic generation control (AGC) of interconnected three unequal area thermal systems, such as integral controller gains (KIi) for the secondary control, governor speed regulation parameters (Ri) for the primary control and frequency bias parameters (Bi), and compare its performance to establish its superiority over genetic algorithm (GA) and classical methods. Comparison of convergence characteristics of BF, GA, and classical approach reveals that the BF algorithm is quite faster in optimization, leading to reduction in computational burden and giving rise to minimal computer resource utilization. Simultaneous optimization of KIi, Ri, and Bi parameters which surprisingly has never been attempted in the past, provides not only best dynamic response for the system but also allows use of much higher values of Ri (than used in practice), that will appeal to the power industries for easier and cheaper realization of governor. Sensitivity analysis is carried out which demonstrates the robustness of the optimized KIi, Ri, and Bi to wide changes in inertia constant (H), reheat time constant (Tr), reheat coefficient (Kr), system loading condition, and size and position of step load perturbation.

An assemblage of predominantly metasedimentary rocks in the Eastern Ghats Province, India, underwent granulite facies metamorphism and deformation in early Neoproterozoic times, and was subsequently intruded by the Koraput alkaline complex. The intrusion was earlier believed to be syn- to late tectonic. The gabbroic core of the complex hosts nepheline-bearing syenitic dykes and veins. Following emplacement, magmatic amphibole within the syenites, and early orthopyroxene in feldspathic gneisses within the country rocks were retrogressed to biotite during pervasive solid-state deformation. Subsequent prograde metamorphism resulted in the formation of anhydrous assemblages at the expense of relict magmatic amphibole within the syenites, and metamorphic biotite in both the complex and the country rocks. Reactions reconstructed from textural observations indicate breakdown of biotite and amphibole to garnet + clinopyroxene ± orthopyroxene-bearing assemblages. Schreinemakers’ analysis on the relevant mineral associations suggests that heating was followed by loading of the region. This indicates thermal rejuvenation of the complex and the host granulites during an intracrustal orogeny that post-dates emplacement and cooling of the pluton. Available ages suggest that this event occurred in the mid-Neoproterozoic, and is probably unrelated to the amalgamation of the granulite belt with the Archaean Bastar/Dharwar craton.

Several power system stabilizers (PSS) connected in number of machines in a multi-machine power systems, pose the problem of appropriate tuning of their parameters so that overall system dynamic stability can be improved in a robust way. Based on the foraging behavior of Escherichia coli bacteria in human intestine, this paper attempts to optimize simultaneously three constants each of several PSS present in a multi-machine power system. The tuning is done taking an objective function that incorporates a multi-operative condition, consisting of nominal and various changed conditions, into it. The convergence with the proposed rule based bacteria foraging (RBBF) optimization technique is superior to the conventional and genetic algorithm (GA) techniques. Robustness of tuning with the proposed method was verified, with transient stability analysis of the system by time domain simulations subjecting the power system to different types of disturbances.

A computational model based on non-relativistic approach is proposed for the determination of transmission coefficient, resonant tunneling energies, group velocity, resonant tunneling lifetime and traversal time in multibarrier systems (GaAs/AlyGa1−yAs) for the entire energy range e V0, V0, being the potential barrier height. The resonant energy states were found to group into allowed tunneling bands separated by forbidden gaps. The tunneling lifetime and the traversal time are found to have minimum values at the middle of each allowed band. Further, It is observed that the electrons with energies in the higher tunneling band could tunnel out faster than those with energies in the lower band. Moreover, an additional resonant peak in resonant energy spectrum indicated the presence of a surface state where resonant tunneling occurs.

This paper deals with automatic generation control of an interconnected hydrothermal system in continuous-discrete mode using conventional integral and proportional-integral controllers. Appropriate generation rate constraint has been considered for the thermal and hydro plants. The hydro area is considered with either mechanical or electric governor and thermal area is considered with either single or double reheat turbine. Performances of mechanical governor, electric governor, and single stage reheat turbine and two stage reheat turbine on dynamic responses have been explored. Further, selection of suitable value of speed regulation parameter R and sampling period has been investigated. System performance is examined considering 1% step load perturbation in either thermal or hydro area.

Photoinduced electron transfer between octadecylrhodamine B (a hole donor) and N, N-dimethyl-1-napthylamine (hole acceptor), located in the head group region of sodium dodecylsulfonate micelles, has been examined for different acceptor concentrations using time resolved fluorescence. The experimental results were analyzed using the Marcus distance-dependent transfer rate modified to take into account the heterogeneous nature of the micelles. Diffusion of the donor/acceptors is included in the theoretical analysis. The results are compared with earlier experiments involving the same donor–acceptor combination but in a different type of micelle. r 2005 Elsevier B.V. All rights reserved. PACS: 78.47.+p; 82.33.Nq; 82.70.Uv

Intermolecular photoinduced electron transfer between Rhodamine 3B cation (R3B+), and dimethylanaline (DMA) is studied in a variety of solvents using pump−probe spectroscopy from ultrashort times (∼100 fs) to long times (∼10 ns). Excitation of R3B+ results in the transfer of an electron from DMA and the production of the neutral radical R3B and the DMA+ radical cation. Using a very broadband continuum probe, the generation of the R3B neutral radical is observed (430 nm) as well as the ground state bleach (550 nm), an excited state absorption (445 nm), and stimulated emission (620 nm). A good spectrum of the R3B radical is obtained by removing the overlapping excited state absorption. The forward electron transfer is examined by monitoring the time dependence of the stimulated emission. The data are analyzed with a previously presented detailed theory of through-solvent electron transfer for diffusing donors and acceptors, which includes the influences solvent structure and the hydrodynamic effect. Previou...

This paper presents the solution of economic load dispatch (ELD) with Lineflow constraints through the application of genetic algorithm (GA). Two representative systems, i.e. IEEE 14 bus [Calculations and programs for power system networks (1986)] and IEEE 30 bus [Calculations and programs for power system networks (1986)] systems have been considered for the investigations. The ELD results with GA have been compared with those obtained through Classical Technique [IEE Proc C 139(4) (1992)], Linear Programming [IEEE Trans Power Syst, 1986] and Quadratic Programming [IEE Proc C 136(3) (1989)] techniques.

Sol-gel synthesized bismuth ferrite (BiFeO3) nanoparticles (NPs) were encapsulated with SiO2 by the Stober method. The structural and microstructural studies were carried out by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). The XRD pattern revealed the coating of SiO2 on distorted rhombohedral (R3c) structured BiFeO3 (BFO). The particle size of BFO was estimated to be 100–120 nm. The inter-planar spacing between the (1 1 0) planes was found to be 0.28 nm. The coating of amorphous SiO2 shell on crystalline BFO was quite evident from the TEM micrographs. The presence of O–Si–O stretching vibration in FTIR spectra reconfirmed the coating of SiO2. The direct bandgap energy was calculated to be 2.02 eV for BFO and 2.12 eV for BFO@SiO2 (from UV–vis spectra). The optical absorption was observed to be higher for BFO@SiO2 than BFO. These NPs may be used as photoelectrodes in dye sensitized solar cell application.

The paper presents an approach based on integral of squared error (ISE) technique for tuning of the parameters of power system stabilizers (PSS) in a multi-machine power system. The PSS are tuned sequentially, depending on which machine needs stabilization most. However, later it has been establishes that if the tuning algorithm is iterated twice or more, no particular tuning sequence is necessary. Dynamic performance with PSS tuned by the proposed method is compared with a previously reported approach in which all the stabilizers are tuned simultaneously. The proposed approach provides satisfactory system dynamic performance and the method is computationally much simpler.

The paper presents the analysis of automatic generation control (AGC) of a two-equal area reheat thermal system in the presence of generation rate constraints considering a discrete-continuous time mathematical model. The effect of variation of sampling period on optimum integral gain setting and system dynamic performance has been analyzed considering supplementary controllers based on conventional area control errors (ACEs) and new area control errors (ACENs). Investigations reveal that the optimum integral gain setting and system dynamic performance are hardly affected over a wide range of sampling period T for controllers based on conventional ACEs. Studies also reveal that the permissible sampling period is further enhanced with integral controllers based on new area control errors (ACENs).

In this research, an inductive displacement sensor with multiferroic bismuth ferrite core has been realized. The bismuth ferrite sample is synthesized and its structural and dielectric properties are studied. A rod-shaped bismuth ferrite core is prepared and displaced through the inductor of a RLC circuit. The performance of the prepared bismuth ferrite core has been compared with a commercially available ferrite core.

This paper presents a control scheme, for automatic generation control (AGC) of both two and three unequal area thermal system, having reheat turbines and generation rate constraints, based on multilayer perceptron neural network (MLPNN) whose weights are updated using reinforcement learning. The weights of MLPNN controller are adjusted dynamically onlinely using backpropagation updation technique with area control error (ACE) as the error and input being the summation of deviation in frequency in the respective area and deviation of tie line power flow. The performance of MLPNN controller considering a wide range of system loading conditions, changes in magnitude of step load perturbation and for simultaneous step load perturbations is compared with the conventional integral controller. Investigation clearly reveals the superior performance of MLPNN controller over the conventional integral controller.