Analysis of Steam Line Break Accident Using PCTRAN Model of VVER-1200 NPP

The investigation of thermal-hydraulic parameters during steam-line break (SLB) accidents is performed by applying the personal computer transient analyzer (PCTRAN) simulator model of the VVER-1200 nuclear power plant (NPP). Five cases, namely, 0.005 m2 (Case-1), 0.01 m2 break (Case-2), 0.02 m2 break (Case-3), 0.04 m2 (Case-4), and 0.08 m2 (case-5) of SLB accident inside containment with the concurrent loss of AC power have been simulated. There was no variation in the timing of the trip of the reactor coolant pumps, the main feedwater pumps, or the turbine in any of the five SLB accidents. However, the reactor scram's onset time varies slightly between the five scenarios. Pressure and temperature in the reactor coolant system (RCS) quickly reached a peak following the start of the SLB accident, fell shortly after the reactor scram, and eventually stabilized in all cases. In comparison to the larger breaks in the SLB accident, the smaller breaks result in a higher RCS temperature and pressure. After the SLB accident, the pressurizer's liquid level rises and then quickly drops in all cases. The break mass flow rate from the steam line rapidly increases until the occurrence of the reactor scram and then decreases to a stabilized value. Steam generator A has a faster rate of heat removal rate than steam generator B, and its pressure and liquid level decrease more quickly than those of steam generator B. The thermal power of the reactor, peak cladding temperature, and fuel temperature showed a rapid drop after the initiation of the SLB accident. There was no increase in these parameters from the initial state of the simulation. The radiation in the air of the reactor building and steam line was very low during the simulation period. Therefore, there was no violation of the safety aspects of the SLB accident of the PCTRAN simulation of the VVER-1200 NPP model

Manufacturing of agricultural machinery in Bangladesh: opportunities and constraints

Despite numerous limitations, agricultural machinery (AM) manufacturing sub-sector inBangladeshis growing quite satisfactorily and has potential to make substantial contribution to much needed non-farm economic growth, employment generation, mechanization of on and off-farm agricultural activities, and as a whole orientation in the national development.  This study made an attempt to take account of AM manufacturers, importers, traders/wholesalers and retailers, their associations, assess market potential and identify serious bottlenecks associated with this sub-sector.  Stratified random sampling technique was used for identifying respondents in quantitative survey, while focus group discussions (FGDs) and Key Informant Interviews (KIIs) were conducted for qualitative investigation.  In recent years, there are about 70 foundries, 800 agricultural machinery manufacturing industries and workshops, 1,500 spare parts manufacturing workshops, and about 20,000 repair and maintenance workshops are engaged in AM sub-sector of the country.  The annual estimated market size of AM and spare parts in the country is about US$802.3 million with an US$ 105.2 million annual repair and maintenance service market, estimating an annual total AM market size of about US$907.5 million of which local production market share is about     US$ 402.7 million.  The spare parts market size in the country is about US$309.3 million of which domestic production of spare parts is estimated US$ 237.9 million.  The significant shift in the supply of spare parts in the country underlines the growth potential of the local spare parts manufacturing sub-sector and potential for substitution of imported spare parts.  Bogra has emerged as the center of manufacturing AM and spare parts especially for irrigation pumps, threshers, maize shellers, piston, liner and numerous spare parts of small diesel engines and machines, casting of machine components etc. and contributing about 80% of the local production in the country.  However, infrastructures for production of AM and spare parts in Bogra and elsewhere in the country are still inadequate. The study recommends declaration of Borga and Jessore as ‘Agri-machinery districts’ and establishment of special ‘Agri-machinery Production Zones (APZ)’ in these areas.  To promote export market to Indian subcontinent and other developing countries, tariff and non-tariff restrictions would be waved on AM through bilateral negotiations and border markets (hats) withIndiato be allowed for AM sales. 

Effects of alternating current voltage amplitude and oxide capacitance on mid-gap interface state defect density extractions in In0.53Ga 0.47As capacitors

This work looks at the effect on mid-gap interface state defect density estimates for In0.53Ga0.47As semiconductor capacitors when different AC voltage amplitudes are selected for a fixed voltage bias step size (100 mV) during room temperature only electrical characterization. Results are presented for Au/Ni/Al2O3/In0.53Ga0.47As/InP metal–oxide–semiconductor capacitors with (1) n-type and p-type semiconductors, (2) different Al2O3 thicknesses, (3) different In0.53Ga0.47As surface passivation concentrations of ammonium sulphide, and (4) different transfer times to the atomic layer deposition chamber after passivation treatment on the semiconductor surface—thereby demonstrating a cross-section of device characteristics. The authors set out to determine the importance of the AC voltage amplitude selection on the interface state defect density extractions and whether this selection has a combined effect with the oxide capacitance. These capacitors are prototypical of the type of gate oxide material stacks that could form equivalent metal–oxide–semiconductor field-effect transistors beyond the 32 nm technology node. The authors do not attempt to achieve the best scaled equivalent oxide thickness in this work, as our focus is on accurately extracting device properties that will allow the investigation and reduction of interface state defect densities at the high-k/III–V semiconductor interface. The operating voltage for future devices will be reduced, potentially leading to an associated reduction in the AC voltage amplitude, which will force a decrease in the signal-to-noise ratio of electrical responses and could therefore result in less accurate impedance measurements. A concern thus arises regarding the accuracy of the electrical property extractions using such impedance measurements for future devices, particularly in relation to the mid-gap interface state defect density estimated from the conductance method and from the combined high–low frequency capacitance–voltage method. The authors apply a fixed voltage step of 100 mV for all voltage sweep measurements at each AC frequency. Each of these measurements is repeated 15 times for the equidistant AC voltage amplitudes between 10 mV and 150 mV. This provides the desired AC voltage amplitude to step size ratios from 1:10 to 3:2. Our results indicate that, although the selection of the oxide capacitance is important both to the success and accuracy of the extraction method, the mid-gap interface state defect density extractions are not overly sensitive to the AC voltage amplitude employed regardless of what oxide capacitance is used in the extractions, particularly in the range from 50% below the voltage sweep step size to 50% above it. Therefore, the use of larger AC voltage amplitudes in this range to achieve a better signal-to-noise ratio during impedance measurements for future low operating voltage devices will not distort the extracted interface state defect density

Emergence of mobile colistin resistance (mcr-8) in a highly successful Klebsiella pneumoniae sequence type 15 clone from clinical infections in Bangladesh

The emergence of mobilized colistin resistance genes (mcr) has become a serious concern in clinical practice, compromising treatment options for life-threatening infections. In this study, colistin-resistant Klebsiella pneumoniae harboring mcr-8.1 was recovered from infected patients in the largest public hospital of Bangladesh, with a prevalence of 0.3% (3/1,097). We found mcr-8.1 in an identical highly stable multidrug-resistant IncFIB(pQil) plasmid of ∼113 kb, which belonged to an epidemiologically successful K. pneumoniae clone, ST15. The resistance mechanism was proven to be horizontally transferable, which incurred a fitness cost to the host. The core genome phylogeny suggested the clonal spread of mcr-8.1 in a Bangladeshi hospital. Core genome single-nucleotide polymorphisms among the mcr-8.1-positive K. pneumoniae isolates ranged from 23 to 110. It has been hypothesized that mcr-8.1 was inserted into IncFIB(pQil) with preexisting resistance loci, blaTEM-1b and blaCTX-M-15, by IS903B. Coincidentally, all resistance determinants in the plasmid [mcr-8.1, ampC, sul2, 1d-APH(6), APH(3′′)-Ib, blaTEM-1b, blaCTX-M-15] were bracketed by IS903B, demonstrating the possibility of intra- and interspecies and intra- and intergenus transposition of entire resistance loci. This is the first report of an mcr-like mechanism from human infections in Bangladesh. However, given the acquisition of mcr-8.1 by a sable conjugative plasmid in a successful high-risk clone of K. pneumoniae ST15, there is a serious risk of dissemination of mcr-8.1 in Bangladesh from 2017 onwards

Household transmission investigation for Corona Virus Disease 2019 (COVID-19) in a rural and urban population of north India.

BackgroundTransmissibility within closed settings, such as households, can provide a strategic way to characterize the virus transmission patterns because the denominator can be well defined. We aimed to characterize the household transmission of Severe Acute Respiratory Syndrome Coronavirus (SARS CoV-2) and its associated risk factors.MethodsThis prospective case-ascertained study was conducted among the household contacts of laboratory-confirmed SARS CoV-2 cases residing in Ballabgarh, Haryana. We enrolled 148 index cases and their 645 household contacts between December 16, 2020 and June 24, 2021. We defined household contact as any person who had resided in the same household as a confirmed COVID-19 case. Baseline data collection and sample collection for real time- reverse transcriptase polymerase chain reaction (RT-PCR) and IgM/IgG against SARS CoV-2 were done on day 1 visit, and followed for a period of 28 days. RT-PCR was repeated on day 14 or whenever the contact is symptomatic and blood sample for serology was repeated on day 28. We estimated household secondary infection rate (SIR) and other epidemiological indicators-median incubation period and serial interval. We employed binomial logistic regression to quantify risk factors associated with infection.ResultsThe household SIR was 30.5% (95% CI: 27.1-34.1%). The secondary clinical attack rate was 9.3% (95% CI: 7.2-11.8). The risk factors that showed higher susceptibility to infection were household contacts who were the primary care giver of the case, whose index cases were symptomatic, those with underlying medical conditions, those living in overcrowded households, who were sharing toilet with the index cases and also who were not wearing a mask when coming in contact with the case. The median (IQR) incubation period was 4 days (4, 5), mean (SD) serial interval 6.4 (±2.2) days, and median (IQR) serial interval 5 days (5, 7).ConclusionHouseholds favour secondary transmission of SARS CoV- 2, hence, index cases are recommended to self-isolate and wear masks; and household contacts to follow strict COVID infection control measures within households when a family member is infected

Electrical conductivity and total dissolved solid of raw milk for the detection of bovine subclinical mastitis

Background and Aim: Bovine subclinical mastitis (SCM) is highly prevalent among dairy cattle. A cross-sectional study was conducted in Bangladesh to evaluate the performance of electric conductivity (EC) and total dissolved solids (TDS) tests for the detection of SCM. Materials and Methods: We randomly selected 108 milk samples from cows of different breeds in the primary milk-producing region of Pabna and Sirajgonj districts of Bangladesh. Samples were subjected to the California mastitis test (CMT), white side test (WST), electric conductivity (EC), TDS, and culture. A cow was considered positive for SCM if it tested positive in CMT, WST, and culture, whereas a cow was considered negative for SCM if it tested negative in all three methods. These gold standards have been used to evaluate the performance of the EC and TDS tests. The optimal EC and TDS cutoff values for the detection of SCM were determined using the “optimal cutoff” function in R version 4.3.1. Results: The optimal EC cutoff value for SCM detection was found to be 6159 μS/cm or 6.16 mS/cm. A positive likelihood ratio (LR+) of 31.2 and an area under the curve (AUC) of 0.905 were obtained for this cutoff value. The optimal cutoff value for TDS was 3100 mg/L of milk, which resulted in a positive LR+ of 45.5 and an AUC of 0.924. Conclusion: To the best of our knowledge, this is the first study to evaluate the performance of EC and TDS tests in detecting SCM in Bangladesh. These results suggest that EC and TDS tests, which are inexpensive, rapid, and easy to conduct, can effectively detect SCM at the farm level

Reducing Opioid Use for Chronic Pain With a Group-Based Intervention: A Randomized Clinical Trial

IMPORTANCE: Opioid use for chronic nonmalignant pain can be harmful. OBJECTIVE: To test whether a multicomponent, group-based, self-management intervention reduced opioid use and improved pain-related disability compared with usual care. DESIGN, SETTING, AND PARTICIPANTS: Multicentered, randomized clinical trial of 608 adults taking strong opioids (buprenorphine, dipipanone, morphine, diamorphine, fentanyl, hydromorphone, methadone, oxycodone, papaveretum, pentazocine, pethidine, tapentadol, and tramadol) to treat chronic nonmalignant pain. The study was conducted in 191 primary care centers in England between May 17, 2017, and January 30, 2019. Final follow-up occurred March 18, 2020. INTERVENTION: Participants were randomized 1:1 to either usual care or 3-day-long group sessions that emphasized skill-based learning and education, supplemented by 1-on-1 support delivered by a nurse and lay person for 12 months. MAIN OUTCOMES AND MEASURES: The 2 primary outcomes were Patient-Reported Outcomes Measurement Information System Pain Interference Short Form 8a (PROMIS-PI-SF-8a) score (T-score range, 40.7-77; 77 indicates worst pain interference; minimal clinically important difference, 3.5) and the proportion of participants who discontinued opioids at 12 months, measured by self-report. RESULTS: Of 608 participants randomized (mean age, 61 years; 362 female [60%]; median daily morphine equivalent dose, 46 mg [IQR, 25 to 79]), 440 (72%) completed 12-month follow-up. There was no statistically significant difference in PROMIS-PI-SF-8a scores between the 2 groups at 12-month follow-up (-4.1 in the intervention and -3.17 in the usual care groups; between-group difference: mean difference, -0.52 [95% CI, -1.94 to 0.89]; P = .15). At 12 months, opioid discontinuation occurred in 65 of 225 participants (29%) in the intervention group and 15 of 208 participants (7%) in the usual care group (odds ratio, 5.55 [95% CI, 2.80 to 10.99]; absolute difference, 21.7% [95% CI, 14.8% to 28.6%]; P < .001). Serious adverse events occurred in 8% (25/305) of the participants in the intervention group and 5% (16/303) of the participants in the usual care group. The most common serious adverse events were gastrointestinal (2% in the intervention group and 0% in the usual care group) and locomotor/musculoskeletal (2% in the intervention group and 1% in the usual care group). Four people (1%) in the intervention group received additional medical care for possible or probable symptoms of opioid withdrawal (shortness of breath, hot flushes, fever and pain, small intestinal bleed, and an overdose suicide attempt). CONCLUSIONS AND RELEVANCE: In people with chronic pain due to nonmalignant causes, compared with usual care, a group-based educational intervention that included group and individual support and skill-based learning significantly reduced patient-reported use of opioids, but had no effect on perceived pain interference with daily life activities. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN49470934

Trends in Use of Referral Hospital Services for Care of Sick Newborns in a Community-based Intervention in Tangail District, Bangladesh

The Projahnmo-II Project in Mirzapur upazila (sub-district), Tangail district, Bangladesh, is promot\uading care-seeking for sick newborns through health education of families, identification and referral of sick newborns in the community by community health workers (CHWs), and strengthening of neo\uadnatal care in Kumudini Hospital, Mirzapur. Data were drawn from records maintained by the CHWs, referral hospital registers, a baseline household survey of recently-delivered women conducted from March to June 2003, and two interim household surveys in January and September 2005. Increases were observed in self-referral of sick newborns for care, compliance after referral by the CHWs, and care-seeking from qualified providers and from the Kumudini Hospital, and decreases were observed in care-seeking from unqualified providers in the intervention arm. An active surveillance for illness by the CHWs in the home, education of families by them on recognition of danger signs and counsel\uadling to seek immediate care for serious illness, and improved linkages between the community and the hospital can produce substantial increases in care-seeking for sick newborns