An enhanced control system for single-phase inverters interfaced with weak and distorted grids

© 2019 IEEE. This paper presents an enhanced current controller for improving the performance of a class of single-phase grid-connected inverters operating in weak and distorted grid conditions. An inverter designed to operate at normal (strong or stiff and clean) grid conditions may not perform satisfactorily during weak and distorted grid conditions. One major reason is the interfering dynamics of the synchronization or phase-locked loop (PLL). This paper proposes an enhanced control structure for a popular class of single-phase inverters to address this problem. The proposed idea is to include the PLL state variables into the main inverter controller thereby minimizing the undesirable interactions of the PLL with the other components. A method for optimally designing the controller gains is also proposed. Compared to the conventional one, the proposed controller is shown to have a more robust performance over a substantially wider range of weak and distorted grid conditions. Extensive simulation and experimental results are presented to validate the proposed controls

Knowledge and Attitude on Legalization of Abortion among Undergraduate Students

Background: Abortion is public health concern in many parts of the world and is also contentious issue with religious, moral, cultural and political dimensions. Awareness program has most essential role to prevent the unusual death of mothers in the world. Objectives: To assess the knowledge and attitude on legalization of abortion among undergraduate students. Methods: A cross-sectional descriptive research design was used for this study. Proportionate stratified sampling technique and simple random sampling technique was used to select the subjects. Total 90 students were chosen as a sample and structured self-administered questionnaire was used to collect data. Results: The mean age of the respondents was 19.82. Most 58 (64.40%) of the respondents were females; majority 76 (84.40%) of the respondents were of upper caste group. Most 85 (94.4%) of the respondents had adequate knowledge on legalization of abortion and majority 83 (94.30%) of the respondents had positive attitude towards legalization of abortion. The study shows that the most knowledgeable area was on concept of abortion (88.55%) and the least knowledgeable (58.00%) area was on method of abortion. Factors like age, gender, residence and educational faculty were not found to be associated with knowledge on legalization of abortion. Conclusions: Undergraduate students had good level of knowledge and attitude on legalization of abortion. Highest knowledge was present in concept of abortion and lowest in methods of abortion. More awareness program should be accessible to undergraduates in order to increase the level of knowledge. J-GMC-N | Volume 11 | Issue 01 | January-June 2018, Page: 52-5

Factors affecting the uptake of institutional delivery, antenatal and postnatal care in Nawalparasi district, Nepal

© 2019, Kathmandu University. All rights reserved. Background Maternal deaths and complications are highly preventable with good antenatal, postnatal and skilled care during childbirth. Inadequate information on the factors affecting these services could be barrier to a reduction of maternal deaths in low-income countries. Objective To assess the uptake of antenatal, postnatal and skilled care during childbirth. Method A cross-sectional study was conducted in eight villages of Nawalparasi district in southern Nepal. A total of 447 women who had given birth within the preceding 24 months were recruited using multistage random sampling. Data were collected using a pre-tested semi-structured questionnaire. Chi-square tests were used to assess association between variables. Result Over 70% of women had gone for at least four antenatal care check-ups while only 14.3% had at least three postnatal check-ups in their last pregnancies. The proportion of institution delivery was 54%. Women’s literacy was associated with the uptake of antenatal services (p=<0.001), postnatal care (p=0.04) and institutional delivery (p=<0.001). Knowledge of antenatal (p=<0.001) and postnatal care was also associated with uptake of respective services (p=<0.001). Conclusion The uptake and knowledge of antenatal care was much better than of postnatal care. Home delivery rates were still very high. A scaling-up of education and awareness-raising interventions in this community could help improve the uptake of maternal health services

The White-Box Adversarial Data Stream Model

We study streaming algorithms in the white-box adversarial model, where the stream is chosen adaptively by an adversary who observes the entire internal state of the algorithm at each time step. We show that nontrivial algorithms are still possible. We first give a randomized algorithm for the $L_1$-heavy hitters problem that outperforms the optimal deterministic Misra-Gries algorithm on long streams. If the white-box adversary is computationally bounded, we use cryptographic techniques to reduce the memory of our $L_1$-heavy hitters algorithm even further and to design a number of additional algorithms for graph, string, and linear algebra problems. The existence of such algorithms is surprising, as the streaming algorithm does not even have a secret key in this model, i.e., its state is entirely known to the adversary. One algorithm we design is for estimating the number of distinct elements in a stream with insertions and deletions achieving a multiplicative approximation and sublinear space; such an algorithm is impossible for deterministic algorithms. We also give a general technique that translates any two-player deterministic communication lower bound to a lower bound for {\it randomized} algorithms robust to a white-box adversary. In particular, our results show that for all $p\ge 0$, there exists a constant $C_p>1$ such that any $C_p$-approximation algorithm for $F_p$ moment estimation in insertion-only streams with a white-box adversary requires $\Omega(n)$ space for a universe of size $n$. Similarly, there is a constant $C>1$ such that any $C$-approximation algorithm in an insertion-only stream for matrix rank requires $\Omega(n)$ space with a white-box adversary. Our algorithmic results based on cryptography thus show a separation between computationally bounded and unbounded adversaries. (Abstract shortened to meet arXiv limits.)Comment: PODS 202

Measurement of Formic Acid, Acetic Acid and Hydroxyacetaldehyde, Hydrogen Peroxide, and Methyl Peroxide in Air by Chemical Ionization Mass Spectrometry: Airborne Method

A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I− cluster formation to produce and detect the ion clusters I−(HCOOH), I−(CH3COOH), and I−(HOCH2CHO), respectively. The CIMS also produced and detected I− clusters with hydrogen peroxide and methyl peroxide, I−(H2O2) and I−(CH3OOH), though the sensitivity was lower than with the O2− (CO2) and O2− ion clusters, respectively. For that reason, while the I− peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1m∕z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3% that of formic acid and the response to either 1- or 2-propanol was 1% of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during the Deep Convective Clouds and Chemistry Experiment in 2012

An Ion-Neutral Model to Investigate Chemical Ionization Mass Spectrometry Analysis of Atmospheric Molecules – Application to a Mixed Reagent Ion System for Hydroperoxides and Organic Acids

An ion-neutral chemical kinetic model is described and used to simulate the negative ion chemistry occurring within a mixed-reagent ion chemical ionization mass spectrometer (CIMS). The model objective was the establishment of a theoretical basis to understand ambient pressure (variable sample flow and reagent ion carrier gas flow rates), water vapor, ozone and oxides of nitrogen effects on ion cluster sensitivities for hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HFo) and acetic acid (HAc). The model development started with established atmospheric ion chemistry mechanisms, thermodynamic data and reaction rate coefficients. The chemical mechanism was augmented with additional reactions and their reaction rate coefficients specific to the analytes. Some existing reaction rate coefficients were modified to enable the model to match laboratory and field campaign determinations of ion cluster sensitivities as functions of CIMS sample flow rate and ambient humidity. Relative trends in predicted and observed sensitivities are compared as instrument specific factors preclude a direct calculation of instrument sensitivity as a function of sample pressure and humidity. Predicted sensitivity trends and experimental sensitivity trends suggested the model captured the reagent ion and cluster chemistry and reproduced trends in ion cluster sensitivity with sample flow and humidity observed with a CIMS instrument developed for atmospheric peroxide measurements (PCIMSs). The model was further used to investigate the potential for isobaric compounds as interferences in the measurement of the above species. For ambient O3 mixing ratios more than 50 times those of H2O2, O3−(H2O) was predicted to be a significant isobaric interference to the measurement of H2O2 using O2−(H2O2) at m∕z 66. O3 and NO give rise to species and cluster ions, CO3−(H2O) and NO3−(H2O), respectively, which interfere in the measurement of CH3OOH using O2−(CH3OOH) at m∕z 80. The CO3−(H2O) interference assumed one of its O atoms was 18O and present in the cluster in proportion to its natural abundance. The model results indicated monitoring water vapor mixing ratio, m∕z 78 for CO3−(H2O) and m∕z 98 for isotopic CO3−(H2O)2 can be used to determine when CO3−(H2O) interference is significant. Similarly, monitoring water vapor mixing ratio, m∕z 62 for NO3− and m∕z 98 for NO3−(H2O)2 can be used to determine when NO3−(H2O) interference is significant

A study to Assess the Knowledge Regarding Human Right of Mentally Ill Patient among Community People in Kaski, Pokhara,Nepal

Introduction: Mental health problems raise many human rights issues. People with mental illness are exposed to human rights violation within and outside the health care context. Because of lack of awareness, people with mental illness and their families do not exercise their rights. Psychiatric patients are most vulnerable groups in community. Incidence of violation of rights of mentally ill patients can be avoided if the community people become aware of them. Objective: To assess knowledge regarding human rights and myth of mental illness among community people. Method: A descriptive crosssectional study was conducted among 140 community people of Ritthepani-27, Kaski, Nepal. Non probability convenient sampling technique was adopted to collect the data. Inclusion criteria included head of the family of the selected community who were willing to participate in the study. Data was collected through face to face interview using a structured questionnaire. Results: In the present study, it was found that 46.40% of the community people had inadequate knowledge regarding human rights of mentally ill patients. There was no significant association between demographic variables and knowledge score of the respondents. The study found that more than half of the respondents (51%) had belief that mental illness is not related to physical health. Likewise 36.4% believed mental illness is caused by supernatural power and evil and 30% believed that marriage can cure mental illness. Conclusion: Based on findings, it is concluded that the level of knowledge regarding rights of mentally ill patient is inadequate and there is a high prevalence of myths and misconceptions related to mental illness among the adult population. So, there is need to conduct awareness raising activities in the community

Prevalence of Substance Use and Associated Factors Among High School Adolescents in Rithepani, Lekhnath-2, kaski, Nepal

Background: Substance use is a major public health concern in global settings, and is very common during adolescence period leading to physical and/or mental health complications. This study assessed the prevalence of substance use and associated factors among high school adolescents in Rithepani 2, Lekhnath, Kaski, 2073. Objectives: The study was designed to provide estimates of substance use by school-going adolescents in Lekhnath and to identify risk factors associated with. Methods: A school based cross-sectional study was conducted from 17th October to 21st October, 2016 among eighth to 12th grade high school students in the Rithepani-2, Lekhnath. Participants were select­ed by purposive sampling techniques, and data were collected using questionnaire. Frequency, percentage, means, SD and chi-square test was performed to identify factors associated with substance use. Results: Majority of the respondents 93 (56.4%) belonged to the age group 15 - 18 years. Majority of the respondents 88 (53.3%) were males and 50 (30.3%) were studying in grade 11. Majority of the respondents 140 (84.8%) were Hindus and 104 (63%) of the respondents belonged to upper caste group. In terms of education of the respondents’ parents, majority of the respondents’ mothers 68 (41.2%) had completed their secondary education and similarly, majority of the respondents’ fathers 78 (47.3%) had completed their secondary education. Majority of the respondents’ mothers 129 (78.2%) were housewives and majority of the respondents' fathers 48 (29.1%) were businessmen. Majority of the respondents 136 (82.5%) belonged to nuclear family and 93 (56.4%) had per month family income more than Rs 15,000. Among 165 respon­dents prevalence of substance use was found to be 10 (6%). Regarding the associated factors majority of the respondents 162 (98.2%) had good relation with their parents, 101 (61.2%) respon­dents’ family members do not use substance, 128 (77.6%) respondents reported that substance use was not accepted in their culture. the prev­alence of substance use by the respondents is 6.1% in which five (50%) respondents consume alcohol, eight (80%) take cigarette, one (10%) use tobacco and two (20%) take ganja. Among the substance users, four (40%) reported imitating parents and four (40%) reported curiosity as the cause for them to initiate substance use. Regarding the accessibility of the substances among the respondents who use substances, three (30%) respondents said that it’s very difficult whereas one (10%) said that it’s very easy for them to have access to the substances. Majority of the respondents who use substances 6 (60%) avail the substance/s from their friends. Regarding the Association, there is a significant association between prevalence of substance and substance use by family members with the χ2 value of 7.61 and p-value 0.006 which is less than 0.05 significant level. There is also a significant association between the prevalence of substance use and its cultural acceptance with the χ2 value of 4.65 and p-value of 0.031 which is less than 0.05 significant level. There is a significant association between the prevalence of substance abuse and ethnicity with the χ2 value of 11.81and with the p-value 0.037 which is less than 0.05 significant level. Conclusions: The prevalence of substance use among high school ado­lescent students in selected higher secondary school was found to be 6.1%. There was significant association between prevalence of sub­stances use and cultural acceptance of participants, ethnicity and use of substances by the family members. Based on the findings of the study researcher suggests to initiate awareness and co-ordination program between the school and parents.  Journal of Gandaki Medical College Vol. 10, No. 1, 2017, Page: 43-4

Weak charge form factor and radius of 208Pb through parity violation in electron scattering

We use distorted wave electron scattering calculations to extract the weak charge form factor F_W(q), the weak charge radius R_W, and the point neutron radius R_n, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer q=0.475 fm$^{-1}$. We find F_W(q) =0.204 \pm 0.028 (exp) \pm 0.001 (model). We use the Helm model to infer the weak radius from F_W(q). We find R_W= 5.826 \pm 0.181 (exp) \pm 0.027 (model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in R_W from uncertainties in the surface thickness \sigma of the weak charge density. The weak radius is larger than the charge radius, implying a "weak charge skin" where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius R_n=5.751 \pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm$, from R_W. Here there is only a very small error (strange) from possible strange quark contributions. We find R_n to be slightly smaller than R_W because of the nucleon's size. Finally, we find a neutron skin thickness of R_n-R_p=0.302\pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm, where R_p is the point proton radius.Comment: 5 pages, 1 figure, published in Phys Rev. C. Only one change in this version: we have added one author, also to metadat