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A dynamic output feedback (DOF) controller design is proposed for an indirect vector-controlled induction motor (IVCIM). The proposed controller is an alternative to the conventional proportional integral (PI) one and can be used for improving the dynamic performance of the IVCIM system. A sequential design method is used in which, first, the inner-loop controllers are designed. Then, the designed inner-loop controller is employed to design the outer speed-loop controller. The procedure incorporates the iron loss dynamics of the induction motor model to fetch the benefit of better performance than conventional controller designs neglecting the same. The DOF controller is designed in an H ∞ control framework by solving the iterative linear matrix inequality that makes stator currents and speed response to be robust against load disturbances and parameter variations. A first-order dynamic controller is tested to highlight its superiority over the PI controller. Comparison between the proposed dynamic and conventional PI controller is shown through several experimental results. It depicts enhanced performance by the proposed controller and suitability to industrial use.

Introduction:Drowning is the 3rd leading cause of unintentional injury deaths.As drowning is a preventable cause of mortality, our aims for the benefit of society at large is to minimize the events as far as possible. Objective:A clear knowledge about factors which play a major role behind such incidences is important.It has equal forensic importance as determination of cause and manner of death require thorough investigation. Methodology: We conducted one-year study of demographic variables and the histopathological changes in relation to lung and splenic tissues in cases of drowning deaths, in the hot and humid climatic region of Eastern India.Results: The demographic findings were presented in graphs and charts. However, none of the commonly known autopsy findings (histopathological) are found to be individually confirmatory of drowning. Conclusion:Several factors inclusive of autopsy findings, biochemical examination, radiological and molecular technique,are needed to be taken together as complementary methods to conclude drowning as the cause of death when bodies are recovered from water.

We study the temporal evolution of the mutual information (MI) in a one-dimensional Kitaev chain, coupled to a fermionic Markovian bath, subsequent to a global quench of the chemical potential. In the unitary case, the MI (or equivalently the bipartite entanglement entropy) saturates to a steady-state value (obeying a volume law) following a ballistic growth. On the contrary, we establish that in the dissipative case the MI is exponentially damped both during the initial ballistic growth as well as in the approach to the steady state. We observe that even in a dissipative system, postquench information propagates solely through entangled pairs of quasiparticles having a finite lifetime; this quasiparticle picture is further corroborated by the out-of-equilibrium analysis of two-point fermionic correlations. Remarkably, in spite of the finite lifetime of the quasiparticles, a finite steady-state value of the MI survives in asymptotic times which is an artifact of nonvanishing two-point correlations. Further, the finite lifetime of quasiparticles renders to a finite length scale in these steady-state correlations., Comment: 6+7 pages, 3+5 figures, accepted for publication in PRB(R)

In this work, a concurrent proportional integral (PI) controller design technique is addressed for indirect vector controlled induction motor (IVCIM). For this, a full-order induction motor (IM) model is employed that includes the stator current dynamics. The current-loop proportional integral (PI) controllers are tuned to use the attributes of such dynamics. The robustness against load torque and rotor resistance variations are incorporated in the design problem. This method is implemented using a static output feedback scheme in which iterative linear matrix inequality (ILMI) based H-infinity control technique is applied. The simulation and experimental comparison with existing designs show the superiority of proposed method and practical interest for industry use.

The aim of this paper is to develop a one-dimensional (1-D) discrete-time model or map that will ensure reliable and safe chaotic operation of a modular photovoltaic (PV) power optimizer (PO) system. Based on this 1-D map, we perform the detailed bifurcation analysis and discuss a preliminary design guideline to operate the system into a desired chaotic regime, i.e., just after the golden mean. We show that operating POs in chaotic regime cannot only yield broader power spectrum with reduced spectral peak at the switching frequency harmonics of the system, but also exhibits faster tracking responses with overall conversion efficiency $\eta \geq$ 98%. Moreover, this optimized frequency-domain as well as time-domain performance are numerically analyzed and then verified experimentally using a prototype modular boost-type PV system.

Indirect vector-controlled induction motor (IVCIM) dynamics is well known for having different bifurcation behavior, viz., saddle-node bifurcation, Hopf bifurcation (HB), Bogdanov–Takens bifurcation, and zero-HB. A numerical analysis of these bifurcations for proportional–integral-controlled IVCIM is made in this brief using full-order IM model. Some new observations on the bifurcation behavior are made. Simulation and experimental results are presented validating the bifurcation behaviors.

An examination of mechanical behavior and versatile properties of reused total concrete (RCA) is displayed. RCAs were arranged by employing a coarse total division made of reused concrete coming from a reusing plant in which rubble from concrete structure devastation is collected and reasonably treated. A few concrete blends were arranged by utilizing either the as it was virgin totals (as reference) or 30% coarse reused total supplanting rock and by utilizing two diverse sorts of cement. Distinctive water-to-cement proportions were received extending from 0.40 to 0.60. Concrete workability was continuously within the run 190–200 mm. Concrete compressive quality, flexible modulus, and drying shrinkage was assessed. Comes about gotten appeared that auxiliary concrete up to C32/40 quality course can be made with RAC. Besides, comes about gotten from experimentation were examined in arrange to get valuable data for RAC structure plan, especially in terms of flexible modulus and dry.

Background: The concept of generic prescription is widely accepted in various parts of the world. Nevertheless, it has failed to gain popularity in India due to factors such as nonavailability and distrust on the product quality. However, since 2012, the Government of West Bengal, India, has initiated exclusive generic drug outlets called “fair price medicine shop” (FPMS) inside the government hospital premises in a “public-private-partnership” model. This study was undertaken to evaluate the experience and attitude of patients who were consuming generic drugs purchased from these FPMS. Materials and Methods: It was a questionnaire-based cross-sectional study where we have interviewed 100 patients each consuming generic and branded drugs, respectively. The perceived effectiveness, reported safety, medication adherence, cost of therapy, and availability of drugs was compared between two mentioned groups. Medication adherence was estimated through Drug Attitude Inventory-10. Results: 93% of generic and 87% branded drug users believed that their drugs were effective (P = 0.238) in controlling their ailments. No significant difference (9% generic, 10% branded drug users, P = 1.000) was observed in reported adverse effects between generic and branded drug users. 82% and 77% of patients were adherent generic and branded drugs, respectively (P = 0.289). As expected, a significantly lower cost of generic drugs was observed compared to its branded counterpart. Conclusion: The policy of FPMS implemented by the Government of West Bengal, India appeared to be promising in terms of perceived effectiveness, safety, and adherence of generic drugs from FPMS compared to drugs purchased from open market retailers. Therefore, this study might act as an impetus for the policy-makers to initiate similar models across the country.

Compact size wearable devices require multiple supplies with relative large loading difference, which causes serious cross regulation, large ripple, and oscillation in single-inductor multiple-output (SIMO) DC–DC converter. Thus, a continuous conduction mode/green mode (CCM/GM) relative skip energy control (RSEC) in SIMO is proposed for wearable device power solution. Different from the conventional absolute skip method, the RSEC eliminates unnecessary skip-induced voltage ripple and cross regulation with well regulation performance over wide load and voltage ranges. Optimization between efficiency and voltage ripple achieves low noise supply and reduced switching loss. In addition, smooth transition between CCM and GM provides high power and longer usage time in wearable devices. Furthermore, bidirectional dynamic slope compensation conquers subharmonic oscillation and avoids invalid pulses in the energy delivery operation of current-mode SIMO DC–DC converters. The test chip fabricated in the 0.18 μm CMOS process occupies $2.24\, {\rm mm}^{2}$ active area. Maximum output ripple, overshoot/undershoot, and cross regulation are kept below 40 mV, 27 mV, and 0.0432 mV/mA, respectively.

We study the static and dynamical properties of a long-range Kitaev chain, i.e., a $p$-wave superconducting chain in which the superconducting pairing decays algebraically as $1/l^{\alpha}$, where $l$ is the distance between the two sites and $\alpha$ is a positive constant. Considering very large system sizes, we show that when $\alpha >1$, the system is topologically equivalent to the short-range Kitaev chain with massless Majorana modes at the ends of the system; on the contrary, for $\alpha 1$ and analyze the corresponding Floquet quasienergies. Interestingly, we find that new topologically protected massless end modes are generated at the quasienergy $\pi/T$ (where $T$ is the time period of driving) in addition to the end modes at zero energies which exist in the static case. By varying the frequency of kicking, we can produce topological phase transitions between different dynamical phases. Finally, we propose some bulk topological invariants which correctly predict the number of massless end modes at quasienergies equal to 0 and $\pi/T$ for a periodically kicked system with $\alpha > 1$., Comment: 15 pages, 8 figures

The presence of algebraically decaying long-range interactions may alter the critical as well as topological behaviour of a quantum many-body systems. However, when the interaction decays at a faster rate, the short-range behaviour is expected to be retrieved. Similarly, the long-range nature of interactions has a prominent signature on the out of equilibrium dynamics of these systems, e.g, in the growth of the entanglement entropy following a quench, the propagation of mutual information and non-equilibrium phase transitions. In this review, we summarize the results of long-range interacting classical and quantum Ising chains which have been studied since decades. Thereafter, we focus on the recent developments on the integrable long-range Kitaev chain emphasising the role of long-range superconducting pairing term on determining its topological phase diagram and out of equilibrium dynamics., Comment: 23 pages, 9 figures; Topical Review article; Published version

A simple current sensorless perturb & observer (P&O) to extract maximum power in a photovoltaic (PV) power generation system is proposed in this paper. The existing techniques used for extracting the maximum power in a PV system, requires the current and voltage sensors. The use of current sensors (CS) for tracking maximum power point is completely avoided in the proposed work and the current information is estimated using present-sample observer based on present instant measurements of output and input voltages. This makes the system more simple, less costly, easy to implement and equally reliable. The effectiveness of the proposed method is studied with the help of a suitable simulation carried out in MATLAB environment and for experimental validation a microcontroller is used. The results obtained from the simulations and experimental studies showed that the proposed current sensorless method can track the maximum power point accurately.

A new and simple current sensorless particle swarm optimization (PSO) to extract maximum power under partial shading condition in a photovoltaic (PV) power generation system is proposed in this paper. The existing techniques used for extracting the maximum power in a PV system, in partial shading condition, requires the current and voltage sensors. The use of current sensors (CS) for tracking maximum power point in a partial shading condition is completely avoided in the proposed work. This make the system more simple, less cost, easy to implement and reliable. The effectiveness of the proposed method is studied with the help of a suitable simulation carried in MATLAB platform and for experimental validation a microcontroller is used. The results obtained from the simulations and experimental studies showed that the proposed current sensorless method can track the maximum power point accurately, in partial shading conditions.

A simple current sensorless perturb & observer (P&O) to extract maximum power in a photovoltaic (PV) power generation system is proposed in this paper. The existing techniques used for extracting the maximum power in a PV system, requires the current and voltage sensors. The use of current sensors (CS) for tracking maximum power point is completely avoided in the proposed work and the current information is estimated using an observer. The observer design varies, based on the present and past instant measurements of output and input voltages. This makes the system more simple, less costly, easy to implement and equally reliable. The effectiveness of the proposed method is studied with the help of a suitable simulation carried out in MATLAB environment and for experimental validation a microcontroller is used. The results obtained from the simulations and experimental studies showed that the proposed current sensorless method can track the maximum power point accurately.

We study an integrable system that is reducible to free fermions by a Jordan-Wigner transformation which is subjected to a Fibonacci driving protocol based on two non-commuting Hamiltonians. In the high frequency limit $\omega \to \infty$, we show that the system reaches a non-equilibrium steady state, up to some small fluctuations which can be quantified. For each momentum $k$, the trajectory of the stroboscopically observed state lies between two concentric circles on the Bloch sphere; the circles represent the boundaries of the small fluctuations. The residual energy is found to oscillate in a quasiperiodic way between two values which correspond to the two Hamiltonians that define the Fibonacci protocol. These results can be understood in terms of an effective Hamiltonian which simulates the dynamics of the system in the high frequency limit., Comment: 16 pages, 5 figures; added a discusion of the behavior of the system over very long times; this is the published version

We study an integrable Hamiltonian reducible to free fermions, which is subjected to an imperfect periodic driving with the amplitude of driving (or kicking), randomly chosen from a binary distribution like a coin-toss problem. The randomness present in the driving protocol destabilizes the periodic steady state reached in the limit of perfectly periodic driving, leading to a monotonic rise of the stroboscopic residual energy with the number of periods $(N)$ for such Hamiltonians. We establish that a minimal deviation from the perfectly periodic driving in the present case using such protocols would always result in a bounded heating up of the system with $N$ to an asymptotic finite value. Exploiting the completely uncorrelated nature of the randomness and the knowledge of the stroboscopic Floquet operator in the perfectly periodic situation, we provide an exact analytical formalism to derive the disorder averaged expectation value of the residual energy through a disorder operator. This formalism not only leads to an immense numerical simplification, but also enables us to derive an exact analytical form for the residual energy in the asymptotic limit which is universal, i.e., independent of the bias of coin-toss and the protocol chosen. Furthermore, this formalism clearly establishes the nature of the monotonic growth of the residual energy at intermediate $N$ while clearly revealing the possible nonuniversal behavior of the same.

We investigate the dynamics of two Jordan Wigner solvable models, namely, the one dimensional chain of hard-core bosons (HCB) and the one-dimensional transverse field Ising model under coin-toss like aperiodically driven staggered on-site potential and the transverse field, respectively. It is demonstrated that both the models heat up to the infinite temperature ensemble for a minimal aperiodicity in driving. Consequently, in the case of the HCB chain, we show that the initial current generated by the application of a twist vanishes in the asymptotic limit for any driving frequency. For the transverse Ising chain, we establish that the system not only reaches the diagonal ensemble but the entanglement also attains the thermal value in the asymptotic limit following initial ballistic growth. All these findings, contrasted with that of the perfectly periodic situation, are analytically established in the asymptotic limit within an exact disorder matrix formalism developed using the uncorrelated binary nature of the coin-toss aperiodicity., 13 pages, 4 figures

Analog circuitry-based photovoltaic (PV) maximum power point (MPP) tracking (MPPT) technique is attractive due to its low cost and capability of easy integration with normal dc–dc switching converters. However, realization of classical digital MPPT algorithms using analog circuitries is a challenging task. It necessarily requires to store the information of module voltage/current and power in order to find the desired MPP. While at the same time, improper design of digital MPPT controllers may cause poor tracking performances or limit cycle oscillations to manifest, which are generally seen as being undesirable. This paper proposes a fast and robust analog PV MPP tracker without imposing any external control or perturbation. The fast dynamic performances with absolute robustness are ensured here by integrating the concepts of Utkin's equivalent sliding mode control law and fast-scale stability analysis of actual switched converter systems. Moreover, the superiority of the proposed MPP tracker (in terms of high-tracking performances) over classical ones, and its impact in series-connected converters configuration are analytically demonstrated through the procedure developed in this paper. Finally, the analytical results have been validated by means of simulations and experiments.

In real electrical systems, the parameters of the subsystems are inherently somewhat different. Synchronous behavior in DC micro-grids (MGs) can be achieved by means of the coupling of these subsystems under the condition of parameters mismatch. The method of detuning of one or more internal parameters in a statically coupled system can give rise to amplitude death (AD), a coupling induced stabilization of a dynamical system. This coupling technique has the advantage that this provides an open-loop stability solution for DC-DC converters in a DC MG in the presence of CPLs. The bifurcation analysis shows that the small detuning of parameters under strong coupling eliminates the standard oscillatory behavior from the large region of the parameter space, where the dominance of the AD can be observed. And this AD dominance produces a reliable dynamical control mechanism in the general case of coupled nonlinear oscillators. The goal of this work is to identify the dynamic states of coupled nonlinear oscillators and investigate how the heterogeneity of the system interacts with the coupling to produce coherent behavior.

This paper focuses on identification of vulnerable lines and nodes of the power grid (PG) network whose removal disrupt on its operational capability. Here the topological parameters are derived from CN theory, and these are used to identify the most important elements i.e., lines and nodes of the PGs. Based on this concept, the number of attack strategies are illustrated and also applied to different IEEE bus networks, e.g., IEEE 39 and 300 buses. We show that in case of electrical PG network, weights are related to electric concepts, and that can enhance the representation of the PG. This work identifies the vulnerable lines and nodes of both weighted and unweighted networks, and quantify the results by applying the concept to real AC power flow model. We conclude that a weighted network analysis can give a better vulnerability assessment than that of an unweighted network.

Introduction: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide and associated with multiple systemic involvements. Long-term hypoxia leads to impaired cognitive function and hand dexterity. With the background of few previous researches, we have aimed to assess cognitive function and hand dexterity in the patients with COPD as well as correlation between them and with oxygen saturation (SpO2). Materials and Methods: Data were collected and compared between 52 stable mild-to-moderate hypoxemic COPD patients defined by the Global Initiative for Obstructive Lung Disease Guidelines and 48 age- and sex-matched healthy volunteers attending the outpatient department of a government hospital Kolkata, using a validated questionnaire Mini-Mental State Examination (MMSE) tool for the assessment of cognitive function and the Nine-Hole Peg Test for assessment of hand dexterity. Results: The median (interquartile range [IQR]) value of Hand Dexterity Test for the dominant hand for the test group was 22 (20–24) s, and for the control group, 19 (18–20) s (P

Background: Snakebite-related fatality is among the highest in West Bengal and such patients display variety of clinical features. Precious time is also lost during the transport to health-care centers. Aim: The study was undertaken to find out the incidences and mortality associated with different snakebites and to compare the clinical features between the survivor and nonsurvivors. Materials and Methods: The data were derived from 286 indoor case records of snakebites from a referral hospital of Kolkata during January 2018 to September 2019. Patients' demographic details, exact bite history with subsequent management, clinical profile, and final outcome were compiled for analysis. Student's t-test and Fisher's exact test were performed to find out statistical significance. Results: The mean age of the patients was 28.44 ± 16.92 years and 69.23% were male. Overall, 67.13% of patients required hemodialysis and 13.63% ultimately died. Russell's viper caused the most number of bites (58.04%) and highest mortality (15.66%). Nonsurvivors had significantly higher levels of creatinine, urea, total count, total bilirubin, and prothrombin time and significantly low hemoglobin and platelet counts than that of the survivors. Bite-to-hospital time was also significantly prolonged among nonsurvivors (9.08 ± 9.68 h versus 4.64 ± 5.58 h; P = 0.0001). The highest (29.17%) mortality was observed among those who reported after 12 h of bite. Conclusion: Maximum snakebite-related mortalities were due to Russell's vipers in the current study. Patients with prolonged bite-to-hospital time were most vulnerable. Sepsis, coagulopathy, and acute kidney injury were significantly higher among the nonsurvivors.

As the conventional power systems turn towards smart grids (SGs) on a fast pace, this transition may create new and significant challenges to the existing electrical network security. Along with many important features of the SGs cyber security has emerged to be a critical issue due to the interconnection of several loads, generators, and renewable resources through the communication network. Cyber-physical attacks (CPAs) are classified as the major threatening of SGs security because it may lead to severe consequences such as large blackout and destruction of infrastructures. Cyber switching attacks (CSAs) (as a part CPAs) start to attract the attention due to its severity and speed in destabilizing the SGs, we present in this paper Thyristor-Controlled Braking Resistor (TCBR) as a solution to mitigate this type of attack. TCBR can enable us to stabilize the target generator in a relatively short time.

Decoupling of the stator currents is important for smoother torque response of indirect vector controlled induction motors. Typically, feedforward decoupling is used to take care of current coupling that requires exact knowledge of motor parameters, additional circuitry and signal processing. In this paper, a method is proposed to design the regulating proportional-integral gains that minimize coupling without any requirement of the additional decoupler. The variation of the coupling terms for change in load torque is considered as the performance measure. An iterative linear matrix inequality based H∞ control design approach is used to obtain the controller gains. A comparison between the feedforward and the proposed decoupling schemes is presented through simulation and experimental results. The results show that the proposed scheme is simple yet effective even without additional block or burden on signal processing.

This paper presents modeling and control of a standalone photovoltaic (PV) system in which a battery is used as a backup source for power management between the source and the load. Lead-acid battery is commonly used in high power PV applications due to its low cost and availability in large size. The modeling of PV system and lead-acid battery by using the corresponding equivalent circuits are discussed here. Three independent control loops are proposed to control the standalone PV system; MPPT control loop for extracting maximum power from PV module under different solar irradiation, battery control loop for bidirectional power flow between battery and dc-link through buck-boost converter to keep the input dc voltage constant, and inverter control loop for maintaining good voltage regulation and achieving fast dynamic response under sudden load fluctuations. The stability of the above control loops are verified by using Bode diagram. Finally the proposed method is applied to 2 kW, 110 V, 50 Hz, two-stage single-phase standalone PV system. The simulation and the experimental results are presented to validate the theoretical analysis, effectiveness and feasibility of the proposed control strategy.

To achieve the best optimized performance in terms of stability and dynamic behavior of power electronic converters, it is necessary to use a more advanced control technique and accurate mathematical model. This paper proposes a fixed-frequency hysteretic current (FFHC) controller that uses both sliding-mode control (SMC) technique and fixed-frequency current controller with a hysteresis band to achieve all properties of the variable structure controller. However, realizing such fixed-frequency sliding-mode controller using small-signal-averaged (SSA) model of the power converters and Utkin's equivalent control technique may not be valid for all conditions. We show that it can be applicable only when the fast-scale dynamics of the converter system is stable, which can be achieved successfully by analyzing the stability of the FFHC-controlled buck converter using Filippov method and Floquet theory. The regions of stability are then presented to show the domains of existence of nominal period-1 and higher periodic orbits in 2-D parameter space. We also demonstrate how to derive the equivalent control law from the modified tristate converter topology to design the controller. Finally, the experimental results are presented to validate the effectiveness of this hybrid FFHC controller.

Nonlinear phenomena in power electronic circuits are generally studied through discrete-time maps. However, there exist very few circuit configurations (like, for example, the current-mode-controlled dc-dc converters or current programmed H-bridge inverter) for which the map can be obtained in closed form. In this paper, we show that, in a voltage-mode-controlled dc-dc converter, if the switching is governed by pulse-width modulation of the first kind (PWM-1), an explicit form of the stroboscopic map can be obtained. The resulting discrete-time state space is piecewise smooth, divided into five regions, each with a different functional form. We then analyze the bifurcation behavior using the explicit map and demonstrate the different types of border collision bifurcations that may occur in this system as a fixed point moves from one region to another. This includes the very interesting case of a direct transition from periodicity to quasi-periodicity through the route of border collision bifurcation. Mode-locking periodic windows are also obtained at certain ranges of the parameters. The two-parameter bifurcation diagram is presented, showing the domains of existence of different oscillatory modes in the system parameter plane

In this paper, a cascaded sliding mode control strategy is proposed for a grid-connected inverter system to simultaneously improve the power quality of the local load voltage and the injected grid current. This control scheme also enables a novel seamless transfer operation between grid-connected and stand-alone mode. The controller comprises of an inner voltage loop with proportional controller and an outer current loop with proportional-integral controller. This results that both the injected grid current and the inverter local load voltage have a very low total harmonic distortion (THD). The overall controller is designed on the basis of sliding mode control technique and constant-frequency current controller with a hysteresis band. The controller retains the benefit of hysteretic current control having fast dynamic responses and mitigates the drawback of the variable switching frequency. The proposed method is then applied to 6-kVA, 220V, 50Hz grid-connected 1-ϕ voltage source inverter (VSI) system. The results show that the steady-state response and the dynamic response are quite attractive. Moreover, the THD of load voltage of the inverter and the injected grid current are 1.96% and 2.14% respectively at standard nonlinear load IEC62040-3.

This paper presents modeling and control for a single-phase grid-connected two-stage micro-inverter system. An average signal model has been developed for a single-phase bridge inverter. The proposed controller has three cascaded control loops. The inner current loop consists of a variable frequency hysteric current mode control which regulates output filter inductor current thereby improved system response. The small signal modeling of the proposed control method is discussed. Again, as the dc-link capacitor plays a crucial role in two-stage micro inverter applications, a DC-link voltage controller is employed in outer control loop to keep the bus voltage constant. The grid current loop regulates the injected current to the grid at a reduced THD level. The stability of the above control loops are also verified by using Bode-diagram. Finally the proposed method is then applied to 500 Watts, 110V, 50Hz, two- stage single-phase grid-connected Photo-voltaic (PV) system. The simulation and the experimental results are presented to validate the theoretical analysis, effectiveness and feasibility of the proposed control strategy.

Background: Oral antibiotics are frequently used for acne vulgaris. Cephalexin has documented some success against acne vulgaris in earlier studies. Here the efficacy and safety of Cephalexin have been compared against the standard therapy of Doxycyline.Methods: From September 2010 to June 2011, 100 patients of moderate Acne vulgaris were randomized into two groups to receive oral Doxycyline (100mg once daily) or Cephalexin (500mg thrice daily) in an open label manner for eight weeks. All participants were allowed to use topical 5%Benzoyl peroxide gel twice daily. Efficacy was measured in terms of reduction in the number of facial comedones and inflammatory lesions from baseline after eight weeks.Results: 44 patients from Cephalexin group and48 patients from Doxycyline group completed the study. Both drugs have significantly decreased comedone count as well as the inflammatory lesion count after eight weeks. However, Doxycycline appeared better in terms of Comedone count (14.5±3.07 versus 12.9±4.31, p=0.045) as well as inflammatory lesion count (8.64.1±2.14 versus 7.67±2.46, p=0.047) at the end. The total adverse event was slightly more with Cephalexin (6.81% versus 6.25%, p= 0.912), where Diarrhoea remained the commonest adverse effect (4.54%).Conclusions: Although for the first time oral Cephalexin has displayed efficacy against moderate acne vulgaris in a prospective clinical study, it appeared inferior to Doxycycline over eight weeks. Therefore, it becomes an option only when other oral antibiotics are contraindicated or not tolerated.

Maintaining good voltage regulation and achieving fast dynamic response under sudden load fluctuation are extremely important in distributed generation (DG) as well as uninterrupted power supply (UPS) systems. This paper presents a fixed frequency hysteresis controller, which is implemented on the basis of sliding mode control (SMC) technique and fixed frequency controlled logic with a hysteresis band. The controller retains the benefit of hysteretic current control having fast dynamic responses and mitigates the drawback of the variable switching frequency. Here a ellipsoidal switching surface for the inverter control is taken in phase plane, rather than the time-plot. The control scheme leads to a robust behavior against any load fluctuations. The designed switching surface allows a faster tracking of the externally given sinusoidal reference. The proposed method is then applied to 1-KVA, 110V, 50Hz islanded 1-Φ voltage source inverter (VSI) system. The results show that the dynamic response is quite faster.

Maintaining good voltage regulation and achieving fast dynamic response under sudden load fluctuation are extremely important in distributed generation (DG) as well as uninterrupted power supply (UPS) systems. This paper presents a fixed frequency hysteresis current (FFHC) controller, which is implemented on the basis of sliding mode control (SMC) technique and fixed frequency current controller with a hysteresis band. The controller retains the benefit of hysteretic current control having fast dynamic responses and mitigates the drawback of the variable switching frequency. These have been verified and compared with the carrier based pulse width modulated (PWM) voltage controller under the same load fluctuation. The proposed method is then applied to 6-KVA, 220V, 50Hz islanded 1-Φ voltage source inverter (VSI) system. The results show that the dynamic response is quite faster than that of widely used PWM-controlled inverter systems. Moreover, the total harmonic distortion (THD) of inverter output voltage is 2.14% at standard nonlinear load IEC62040-3.

Optical Fibre Cable (OFC) based network is most suitable for the transport but due to high capital cost involved in OFC laying specially in the congested cities and remote rural areas, it has not been possible so far to extend Broadband internet access to all.