Improvement of test methods and criteria for evaluation of resistance to flame propagation of long elements of the wiring system

The test methods for flame propagation of long elements of the electrical wiring system, in particular, cables, cable conduits and ducts, are analyzed, and differences in them are found in the test conditions and criteria for evaluating the resistance to flame propagation. Using a substrate of a wooden board covered with a layer of tissue paper with an areal density of (21±9) g/m2, adopted for testing other elements of the electrical wiring system, a cable was identified that is not resistant to flame propagation. It is proposed to use this substrate for testing the flame propagation of cables instead of a substrate made of a double layer of filter paper with a surface density of (80±15) g/m2. In one of three experiments, a cable that was not resistant to flame propagation was found based on the criterion of the presence of ignition of the substrate located under it. To reduce the risk of making an incorrect decision on compliance, it is proposed that the assessment of long elements of the wiring system be carried out according to the rules established for cable ducts, trays and ladders in EN 50085-1 and IEC 61537. For the AVVG cable with an outer diameter of 10 mm to 60 mm, when it touches the blue flame cone of 1 kW, the correlation coefficient of the dependence of the length of the charred part on the diameter was 0.969. For a distance of 100 mm between the sample and the burner along its axis, a correlation coefficient of 0.985 was obtained. It is proposed to test cables under the second condition recommended in IEC 60695-11-2. For two conduits, flame propagation was revealed when exposed to a 1 kW flame for 120 s and 240 s. However, for these pipelines, flame propagation did not occur under standard conditions of exposure to such a flame for 20 s and 25 s. To identify long elements of the wiring system that are not resistant to flame propagation, it is proposed to test them at a duration of exposure to a flame of 1 kW, established for cables in IEC 60332-1-2

“COVID 19- Two Waves & More” What Have We Learnt?

The first case of SARS-CoV2 admitted on 26th December 2019 in Central Hospital, Wuhan, China. Broncho-alveolar lavage and Polymerase chain reaction of the aspirate showed high abundance of a viral RNA which has 89.1 % nucleotide identity with bat coronavirus previously isolated in China. Soon human to human transmission was observed and the outbreak started spreading. World Health Organisation on 11th March 2020 declared it as pandemic. COVID 19, caused by SARS-CoV-2, a disease we are still struggling to contain. With vaccination drive throughout the world, though the severity in re-infection has come down, but there is still threat by the various variants which are arising from time to time in various countries. The most effective way of preventing the spread of the virus is to keep physical distance from others of at least 1 meter, wearing a well fitted mask, keep hands clean and use hand sanitizer frequently, stay in well ventilated place, avoid crowded place and cough into bent elbow or tissue paper and get vaccinated when once’s turn comes. Therefore, we urge people to follow COVID appropriate behaviour properly. Keywords: COVID 19, SARS-CoV2, COVID appropriate behaviour, Social Distancing

Hand Hygiene Compliance and Associated Factors among Healthcare Workers in Ethiopia: A Systematic Review and Meta-Analysis

Background. Promoting hand hygiene compliance should be a priority for health authorities and all healthcare facilities at all levels. Therefore, this systematic review and meta-analysis aimed to provide a pooled estimate of hand hygiene compliance and associated factors among healthcare professionals in Ethiopia. Methods. PubMed, Science Direct, EMBASE, the Google search engine, and Google Scholar were used to retrieve studies that were eligible for the study. The searches included all studies published in English prior to July 2021. Using a structured data extraction format, two authors independently extracted the required data. STATA Version 16 software has been used for statistical analysis. To measure the heterogeneity of the studies, the Cochrane Q-test statistics and I2 test were used. Because of the significant heterogeneity, a random-effects model was used. Results. The pooled hand hygiene compliance among healthcare workers in Ethiopia was 38% (95% CI: 0.16–0.59). According to the study’s subgroup analysis, Addis Ababa City administration health workers had the highest hand hygiene compliance, at 73% (95% CI: 0.50–0.96), while SNNP regional state had the lowest, at 9% (95% CI: 0.05–0.13). Presence of hand hygiene promotion (OR: 2.14, 95% CI: 1.04–3.24), towel/tissue paper availability (OR: 3.97, 95% CI: 2.09–5.86), having a positive attitude toward hand hygiene (OR: 1.79, 95% CI: 1.28–2.30), having good knowledge about hand hygiene (OR: 3.45, 95% CI: 1.26–5.64), and being trained for hand hygiene (OR:4.97, 95% CI:1.81–8.14) were significantly associated with hand hygiene compliance. Conclusion. In this analysis, hand hygiene compliance among healthcare workers in Ethiopia was less than half. Providing hand hygiene promotion, towel/tissue paper presence, having a positive attitude toward hand hygiene, having good knowledge about hand hygiene, and being trained for hand hygiene were important variables for the increment of hand hygiene compliance.

Compliance with Covid-19 Non-Medicinal Preventive Protocol and Intent to Accept Covid-19 Vaccine Among Adults in South Eastern Nigeria

Background A Non-pharmaceutical public health measures are being promoted for mitigating the risk and impact of epidemic and pandemic covid-19 influenza and the introduction of its vaccine necessitate the assessment of individual perception regarding the vaccine. This study assessed compliance with covid-19 non-medicinal preventive protocol and intent to accept covid-19 vaccine among adults in Owerri West, Imo state Nigeria. Method Descriptive cross sectional research design was employed in recruiting four hundred and thirty six (436) participants used for the study. Using SPSS version 23, data were subjected to descriptive and Chi-square analysis. Results Results showed that almost all of them 433(99%) have heard about covid-19 especially from radio 151(35%). A vast number of them know the cause of the disease 397(92%) and when and where it was first reported 423(98%). They were aware that the disease is transmitted through respiratory droplet 351(81%) and it can enter the body through the nose 400(92%), mouth 359(83%) and eyes 362(84%). Moreover, almost all of them know that the disease has no cure 398(92%). On their perception, majority of them strongly agreed that the disease is real and is a serious disease but not in Nigeria where most of the participants disagreed that people did not die from the disease 303(69%). Most of them strongly perceived that the disease can be prevented through regular washing of hands with soap 291(67%), maintaining social distance 223(51%), wearing of nose mask 204(47%), cleaning and disinfecting the environment 231(53%). However, most of them sometimes wear nose mask wash their hands with soap 298(68%) and maintain at least one meter distance when with others 283(65%). Equally, the participants sometimes wash cloth nose mask before reuse 288(66%) but never share nose mask with any other person 200(46%). Moreover, most of them sometimes touch face with fingers 231(53%), clean and disinfect door handles 258(59%), tables and chairs 252(58%). Most of them sometimes sneeze/cough into their elbow 244(56%) and dispose tissue paper used for sneezing/coughing into a closed bin 325(75%), travel in a crowded vehicle 244(56%), attend events with more than 50 persons in attendance 189(43%) and in general sometimes follow all the recommended preventive measures 259(59%) resulting in greater proportions of them 197(45%) observing low level of compliance. Major barrier for not observing the preventive measures as reported by majority of the respondents is that hand washing with soap for up to 20 minutes is lack of time 203(47%), feel uncomfortable with wearing of nose mask 180(41%), attend crowded events because it is very crucial 167(38%) and usually touch their face when cleaning sweat 178(41%). Only few of the participants 114(26%) were willing to accept vaccine especially if it given free of charge 151(35%) in liquid form 55(48%) and its safety trusted 352(81%). Prominent reason for not taking vaccine was because of hidden agenda behind it which is not to the advantage of humanity 87(27%) whereas prominent reason for accepting it was to prevent the recipient from getting the disease 88(77%). Conclusion With the exception of religion, all the demographic characteristics had significant influence (p<0.05) on the level of compliance to covid-19 preventive measures and respondents’ intent to accept covid-19 vaccine when provided. Therefore, to increase vaccine acceptability, baseless rumors and myths against the COVID-19 vaccines must be checked and they should be reached out with scientific facts describing the safety and efficacy of the vaccines.

Towards accurate non-contact moisture inspection using THz imaging and thickness information

This study proposes an approach for a non-contact moisture inspection in dried food products, which is crucial to maintain optimal quality and shelf-life, using terahertz (THz) signal. To achieve this, a sample-specific calibration curve needs to be determined first. HAITAI crackers were chosen in this work for demonstration purposes. Fifteen stacks of crackers with different heights were prepared and moisturized by covering with a wet tissue paper for different time periods, resulting in moisture levels between 3 and 40% R.H.. Then, each sample was placed on a conveyor belt system between a THz source and THz a detector, and transmitted signal was measured 5 times. After that, moisture percentage of the sample was determined based on a gravimetric method, whose results served as a ground-truth measurement. A thickness of the sample was also measured using a vernier. All signal measurements, together with their corresponding known thicknesses and moisture percentages, were used to calculate necessary coefficients that define a sample-specific calibration curve. Once a calibration curve for the cracker was obtained, it was used to estimate the moisture percentages in samples with different thicknesses. Mean absolute error (MAE) of the moisture percentage is found to be less than 12% when the sample thickness is modelled as part of the calibration curve, which is over 50 times less compared to the case when the sample thickness is not modelled. Therefore, the utilization of an automatic thickness determination would be promising for real-time and accurate non-contact moisture inspection. This approach can be also integrated into a production line to improve quality control in the food industry without interrupting existing processes.

Tissue Paper-based Composite Separator Using Nano-SiO2 Hybrid Crosslinked Polymer Electrolyte as Coating Layer For Lithium Ion Battery With Superior Security and Cycle Stability

With the development of energy-storage devices, separator is encountered by several challenges including adequate safety, higher current density and superior stability. Tissue paper, composed of packed cellulose fibers, possesses lower production cost, more easily accessibility, superior wettability and outstanding thermostability, thus being prospective as a substrate of high performance separator. To address structure collapse phenomenon occurred in conventional coating layer after long term electrolyte swelling, nano-SiO2 hybrid crosslinked network was constructed on tissue paper through chemical reactions between polymer poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and hyperbranched polyethyleneimine (PEI) in this work. The influences of crosslinking degree on physical properties and electrochemical performance were studied thoroughly. It can be found that when the crosslinking ratio of PVDF-HFP and PEI fixed at 10:1, the crosslinked composite separator displays excellent electrolyte uptake and wettability, superior ionic conductivity, better interfacial compatibility as well as higher Li+ transference number (0.56), thus offering battery with prominent rate capabilities. Besides, this crosslinked composite separator exhibits satisfying dimensional stability even treated at 250 oC, better flame retardancy, enhanced mechanical behavior, wider electrochemical window and outstanding cycle stability. Accordingly, tissue paper-based crosslinked composite separator can meet higher requirements put forward by high power lithium ion battery.