Three phase Two Stage Hysteresis Current Controlled Grid Connected Inverter System

Design and implementation of a hysteresis current controlled grid-connected voltage source inverter (VSI) is presented. The proposed control technique retains the benefit of fast dynamic response, good reference tracking capability and simple implementation. Power from the renewable source is fed to the dc-dc boost converter to meet the grid required voltage level. Boosted voltage is connected to the inverter DC link. Power is fed to the 110V, 50Hz grid. Current injected to the grid is well within the IEEE 519 standard

Seroprevalence and risk factors of herpes simplex virus type-2 infection among pregnant women in Northeast India

<p>Abstract</p> <p>Background</p> <p>Herpes simplex virus type-2 (HSV-2) is one of the most common sexually transmitted infections that facilitate human immunodeficiency virus (HIV) acquisition by over two fold or more. The development of HSV-2 control methods as a measure to control HIV epidemic in high HSV-2/HIV areas has become a priority. Two out of the six high HIV prevalent states of India are located in the Northeastern region of India. Due to lack of documented HSV-2 studies from this part of the country; there was a need for estimating the seroprevalence and risk factors of HSV-2 infection in this defined population.</p> <p>Methods</p> <p>Pregnant women (n = 1640) aged18 years and above attending antenatal clinics of tertiary referral hospitals in five Northeastern states of India were screened for type specific HSV-2 IgG antibodies. Blood samples were collected from all the participants after conducting interviews. Univariate and multivariate analyses were performed to identify the risk factors associated with HSV-2 seropositivity.</p> <p>Results</p> <p>Overall seroprevalence of HSV-2 infection was 8.7% (142/1640; 95% CI 7.3-10.0) with a highest prevalence of 15.0% (46/307; 95% CI 11.0-19.0) in the state of Arunachal Pradesh. Higher seroprevalence was observed with increasing age (Adj. Odds Ratio [AOR] 1.9 for 22-25 years old, AOR 2.29 for > 29 years old). The risk factors associated with HSV-2 seropositives were multiple sex partners (AOR 2.5, <it>p </it>= 0.04), condom non-user's (AOR 4.7, p <it><</it>0.001), early coitarchal age (age of first intercourse) 'less than 18 years' (AOR 9.6, <it>p = </it>0.04), middle income group (AOR 2.1, <it>p = </it>0.001) compared to low income group and low level of education (AOR 3.7, <it>p = </it>0.02) compared to higher education. HSV-2 seropositivity was higher among Christians (12.6%) compared to Muslims (3.8%). The most frequent clinical symptoms among HSV-2 seropositives were excess vaginal discharge in last one year (53.5%, 76/142) and pelvic pain (26.1%, 37/142). While among subjects with genital ulcers, HSV-2 seroprevalence was 36.8% (7/19).</p> <p>Conclusions</p> <p>Overall seroprevalence of HSV-2 infection among pregnant women of Northeast India is relatively low. The generation of awareness among high risk groups may have played key role to limit the infection. The role of vaccination against HSV-2 in near future and elimination of HSV-2 viral shedding along with genital tract inflammation in high HIV/HSV-2 areas may be an option for initiating successful intervention strategies to reduce the transmission and acquisition of HIV infection in Northeast India.</p

SIMULATION OF MODIFIED OCC CONTROLLER FOR THREE PHASE BOOST TYPE GRID CONNECTEDINVERTER WITH PHOTOVOLATIC ARRAY

Now-a-days serious concerns have been raised over the fossil fuel electricity generation, because it pollutes our environment and depletes the energy supply. As a result alternative energy sources such as solar energy and fuel cells have gained great attention because they are friendly to the environment and flexible for installation. In this paper, the one cycle control (OCC) method and the pulse width modulation (PWM) method have been proposed for a three phase boost type grid connected inverter. A cost effective maximum power point tracking method (MPPT) integrated within the OCC. When integrated with a three phase boost type inverter, the proposed method tracks MPP with good precision and solar power is converted into three phase ac power with a single phase power stage. One stage inverters for low dc voltage to high ac voltage conversion have been reported for non-grid connected inverters based on the topology of a current source inverter. The output current of the inverter can be adjusted according to the voltage of the photovoltaic array so as to extract the maximum power from it. Compared with previously proposed approaches, this OCC method preserves the advantages of simple circuitry, good stability, fast dynamic response and maximum power point tracking (MPPT) function can be conveniently integrated into the control core

Becker's birthmark: A case series of pigmented hairy epidermal naevus

Becker's naevus also known as Becker's melanosis (BM) or pigmented hairy epidermal naevus is a cutaneous hamartoma with brown hyperpigmentation and hypertrichosis. It commonly occurs during adolescence and rarely at birth. It usually affects young post-pubertal males and has a prevalence of 0.5%. A naevus usually consists of a circumscribed, unilateral, irregularly shaped, hyperpigmented spot usually located around the anterior upper body, with or without hypertrichosis and/or acneiform lesions. Sometimes developmental abnormalities can occur with Becker's naevus, which is called Becker's naevus syndrome (BNS). Becker's naevus was of atypical presentation in two patients over the forearm and leg. Hence, these case reports gain importance

Evaluation of Comfort Levels of Patient and Ergonomics of the Dental Surgeon during Manual Scaling under Both Proprioceptive Derivative Concept and Conventional Approach: A Cross-sectional Study

Introduction: The important components that contribute to successful dental care are maximum accessibility, visibility, comfort, and control over clinical processes. Dental practitioners are more prone to developing musculoskeletal disorders due to awkward working postures. To minimise all these risk factors, a new concept called Proprioceptive Derivative (PD) has come into existence. Aim: The main aim of this study was to evaluate the comfort levels of the patient and ergonomics of the dental professional in the PD approach and conventional approach. Materials and Methods: A cross-sectional study was conducted in which manual scaling was performed by 20 dentists on 120 patients using the PD concept and conventional concept. A 13-item questionnaire was distributed among the patients and clinicians to record their perceptions of comfort levels, clinicians’ treatment satisfaction levels, and the time needed to complete the procedure after mastering the PD concept. In indepedent sample t-test was use to compare the responses among the two groups. p≤0.05 was considered statistically significant. Results: The comfort levels of the clinician (q1) during treatment in the conventional approach, with a mean value of 2.96±0.69, were significantly lower than in the PD approach, with a mean value of 3.46±0.85 (p<0.001). However, from the perspective of the patients, the mean comfort levels using the conventional strategy were 2.61±1.03, while using the PD approach, it was 2.85±1.11, which was not statistically significant (p>0.05). Conclusion: The clinicians had more ergonomic benefits and improved time factors under the PD concept. By following the work postures according to the PD concept, clinicians can avoid musculoskeletal discomfort, which is beneficial to all clinicians and can increase the longevity of their clinical practice

Realization of a twin beam source based on four wave mixing in Cesium

Four-wave mixing (4WM) is a known source of intense non-classical twin beams. It can be generated when an intense laser beam (the pump) and a weak laser beam (the seed) overlap in a ð3Þ medium (here Cesium vapor), with frequencies close to resonance with atomic transitions. The twin beams generated by 4WM have frequencies naturally close to atomic transitions, and can be intense (gain 1) even in the CW pump regime, which is not the case for PDC ð2Þ phenomenon in nonlinear crystals. So, 4WM is well suited for atom-light interaction and atombased quantum-protocols. Here, we present the ¯rst realization of a source of 4-wave mixing exploiting D2 line of Cesium atoms

Gingival Depigmentation by Application of Diode Laser at 810 nm (Denlase) and 470 nm (Bluelase) Wavelengths: A Split-mouth Randomised Clinical Trial

Introduction: Gingival hyperpigmentation is a common aesthetic concern that often requires treatment to achieve a pleasing smile. While various methods for depigmentation have been described in the literature, the scalpel method is widely advocated. Laser technology, particularly diode lasers, has emerged as a preferred treatment option due to their unique properties. Aim: To compare the efficacy of two different diode wavelengths, namely Denlase and Bluelase lasers, in terms of pain intensity, aesthetic appraisal, and the rate of repigmentation. Materials and Methods: This split-mouth randomised clinical trial was conducted in the Department of Periodontics at Vishnu Dental College, Bhimavarm, Andhra Pradesh, India. over a period of one year with follow-up. A total of 16 patients were included, and the right and left quadrants (both maxilla and mandible) were randomly assigned to either the Denlase or Bluelase group using the coin toss method. Depigmentation using diode lasers at 810 nm and 470 nm wavelengths was carried out in the respective groups. Pain perception, aesthetic appraisal, and recurrence of pigmentation were evaluated at 1, 3, 6, 9 months, and one year. The data were analysed using Friedman’s analysis and the Mann-Whitney U-test. Results: A total of 16 subjects, with a mean age of 27.64±7.64 years and of both genders, were included in the study. Statistically significant differences (p=0.001) were reported in pain perception, aesthetic appraisal, and the rate of repigmentation at 1, 3, 6, 9 months, and one year, respectively. Intergroup comparison revealed an increase in the mean amount of repigmentation at three months in the Denlase group, indicating a recurrence of pigmentation after three months. Conclusion: The Bluelase diode laser (470 nm) demonstrated superior results compared to the Denlase diode laser (810 nm) in terms of pain intensity, aesthetic appraisal, and repigmentation