Comparative study of selected indoor concentration from selective laser sintering process using virgin and recycled polyamide nylon (pa12)

Additive manufacturing (AM) stands out as one of the promising technologies that have huge potential towards manufacturing industry. The study on additive manufacturing impact on the environment and occupational exposure are attracting growing attention recently. However, most of the researcher focus on desktop and fused deposition modelling type and less attention given to the industrial type of AM. Usually, during the selective laser sintering process, recycle powder will be used again to reduce cost and waste. This article compares the PM 2.5, carbon dioxide (CO2) and total volatile organic compound (TVOC) concentration between virgin and recycles powder using polyamide-nylon (PA12) towards indoor concentration. Four phases of sampling involve during air sampling accordingly to the Industry Code of Practice on Indoor Air Quality 2010 by DOSH Malaysia. It was found that PM 2.5 and CO2 concentration are mainly generated during the pre-printing process. The recycle powder tended to appear higher compared to virgin powder in terms of PM 2.5, and CO2. The peak value of PM 2.5 is 1452 μg/m3 and CO2 is 1218 ppm are obtained during the pre-printing process during 8 hours of sampling. TVOC concentration from recycling powder is slightly higher during the post- printing phase where confirm the influence of the powder cake and PA12 temperature from the printing process. In summary, this work proves that elective laser sintering (SLS) machine operators are exposed to a significant amount of exposure during the SLS printing process. Mitigation strategies and personal protective equipment are suggested to reduce occupational exposure

Effects of e-cigarettes versus nicotine replacement therapy on short-term smoking abstinence when delivered at a community pharmacy

E-cigarettes (EC) are now the most popular quit aid in England but their effectiveness for cessation if offered at a pharmacy has not been tested. Here we test the effectiveness of offering an e-cigarette with and without nicotine replacement therapy (NRT) on 4–6-week quit rates in adult smokers seeking support from a community phar- macy. A between subject, six-week, prospective, cohort design. 115 smokers (female=74; M age=46.37, SD = 13.56) chose either an EC, EC + NRT or NRT alone, alongside standard behavioural support. Smokers opting for an EC alone or an EC + NRT were more likely to report complete abstinence from smoking at 4–6weeks (62.2% and 61.5% respectively) compared to NRT alone (34.8%). An EC intervention was sig- nificantly more effective for smoking cessation than NRT in this community pharmacy. The results for e-ci- garettes appear positive but with the caveat that participants chose their own products which may have in- troduced bias

Confinement and Chiral Symmetry Breaking via Domain-Like Structures in the QCD Vacuum

A qualitative mechanism for the emergence of domain structured background gluon fields due to singularities in gauge field configurations is considered, and a model displaying a type of mean field approximation to the QCD partition function based on this mechanism is formulated. Estimation of the vacuum parameters (gluon condensate, topological susceptibility, string constant and quark condensate) indicates that domain-like structures lead to an area law for the Wilson loop, nonzero topological susceptibility and spontaneous breakdown of chiral symmetry. Gluon and ghost propagators in the presence of domains are calculated explicitly and their analytical properties are discussed. The Fourier transforms of the propagators are entire functions and thus describe confined dynamical fields.Comment: RevTeX, 48 pages (32 pages + Appendices A-E), new references added [1,2,4,5] and minor formulae corrected for typographical error

Dose Estimate of radon radioactive pollutants in samples of phosphate fertilizers and pesticides

Proceeding from the fact that agriculture is a long process of intensification through which society sought to meet its ever-increasing needs for food, and the necessity of countries to meet the needs of their populations, which made them resort to various means to meet these needs and as a result of the steady increase in the use of phosphate fertilizers in particular so that agriculture does not become a cause of exacerbation of environmental pollution with materials Radioactive substances and toxins that pose a significant danger to human life and living organisms, with the accompanying dangerous pathological phenomena. This research measured the concentration of radioactive pollutants in phosphate fertilizers. A s well as analyzing the radon levels in phosphate fertilizers and pesticide samples obtained from marketplaces in Iraq. Radiological parameters were measured using nuclear track detectors to calculate yearly effective exposure levels and the corresponding cancer risk. The acquired data were compared to the UNSCEAR's recommended limits and were determined to be within them

The fungicidal effect of sesame essential oil against locally isolated fungi from Al Baha and Baljurash regions

Many fungal strains are invading the plants in the agricultural regions and using chemical-based fungicides may cause harm to the plants the then damage the crops. This study aims to assess the fungicidal effect of the composited sesame oil against locally isolated fungi in Al Baha and Baljurash regions in Saudi Arabia. The isolation process focused on infested fields with fungal infection in 11 regions cultivated with olive plants in Al Baha and Baljurash regions, which were then isolated on Potato Dextrose Agar medium for 7 days at 25 C, to be then identified on the genotypic level using ITS genetic marker suitable chromosomal extraction kits and construct the phylogenetic trees by MEGA 11 software. The major 11 fungal pathogens were belonged to Aspergillus niger, Fusarium equiseti, Alternaria tenuissima, Phoma macrostoma, Alternaria alternata, and Aspergillus flavus. While only one nonpathogenic fungal strain was isolated (Trichoderma harzianum). The antifungal activity of the sesame oil in two concentrations was assessed against the isolated fungal strains, the extracted sesame oil with 20 ml concentration showed a promising activity when compared to plain PDA and 10 ml concentration (90.96 to 2.05 mm). In conclusion, sesame oil with maximum concentration can reveal strong fungicidal activity when compared to commercial fungicides and zinc ferrite nanoparticles, therefore, several antifungal approaches must be implemented to combat fungal infections in Al Baha region

Antibiotics for coughing in general practice: a questionnaire study to quantify and condense the reasons for prescribing

BACKGROUND: Antibiotics are being overprescribed in ambulant care, especially for respiratory tract infections (RTIs). Gaining insight into the actual reasons for prescribing remains important for the design of effective strategies to optimise antibiotic prescribing. We aimed to determine items of importance for the antibiotic prescribing decision and to make them operational for an intervention trial. METHODS: A postal questionnaire based upon focus group findings was sent to 316 Flemish general practitioners (GPs). On a verbal rating scale the GPs scored to what extent they consider the questionnaire items in decision making in case of suspected RTI in a coughing patient and how strongly the items support or counter antibiotic treatment. Factor analysis was used to condense the data. The relative importance of the yielded operational factors was assessed using Wilcoxon Matched Pairs test. RESULTS: 59.5% completed the study. Response group characteristics (mean age: 42.8 years; 65.9% men) approximated that of all Flemish GPs. Participants considered all the items included in the questionnaire: always the operational factor 'lung auscultation', often 'whether or not there is something unusual happening' – both medical reasons – and to a lesser extent 'non-medical reasons' (P < 0.001). Non-medical as well as medical reasons support antibiotic treatment, but non-medical reasons to a lesser extent (P < 0.001). CONCLUSION: This study quantified, condensed and confirmed the findings of previous focus group research. Practice guidelines and interventions to optimise antibiotic prescribing have to take non-medical reasons into account

Influence of patient symptoms and physical findings on general practitioners' treatment of respiratory tract infections: a direct observation study

BACKGROUND: The high rate of antibiotic prescriptions general practitioners (GPs) make for respiratory tract infections (RTI) are often explained by non-medical reasons e.g. an effort to meet patient expectations. Additionally, it is known that GPs to some extent believe in the necessity of antibiotic treatment in patients with assumed bacterial infections and therefore attempt to distinguish between viral and bacterial infections by history taking and physical examination. The influence of patient complaints and physical examination findings on GPs' prescribing behaviour was mostly investigated by indirect methods such as questionnaires. METHODS: Direct, structured observation during a winter "cough an cold period" in 30 (single handed) general practices. All 273 patients with symptoms of RTI (age above 14, median 37 years, 51% female) were included. RESULTS: The most frequent diagnoses were 'uncomplicated upper RTI/common cold' (43%) followed by 'bronchitis' (26%). On average, 1.8 (95%-confidence interval (CI): 1.7–2.0) medicines per patient were prescribed (cough-and-cold preparations in 88% of the patients, antibiotics in 49%). Medical predictors of antibiotic prescribing were pathological findings in physical examination such as coated tonsils (odds ratio (OR) 15.4, 95%-CI: 3.6–66.2) and unspecific symptoms like fatigue (OR 3.1, 95%-CI 1.4–6.7), fever (OR 2.2, 95%-CI: 1.1–4.5) and yellow sputum (OR 2.1, 95%-CI: 1.1–4.1). Analysed predictors explained 70% of the variance of antibiotic prescribing (R(2 )= 0,696). Efforts to reduce antibiotic prescribing, e.g. recommendations for self-medication, counselling on home remedies or delayed antibiotic prescribing were rare. CONCLUSIONS: Patient complaints and pathological results in physical examination were strong predictors of antibiotic prescribing. Efforts to reduce antibiotic prescribing should account for GPs' beliefs in those (non evidence based) predictors. The method of direct observation was shown to be accepted both by patients and GPs and offered detailed insights into the GP-patient-interaction

The fungicidal effect of Rosa Damascena Mill extracts against fungal infections invading Plants in Al Taif

Plant pathogens of fungus have become of the most crucially harmful objects that may affect overall plants growth rate and crops production worldwide. This study involved the identification of six species and six genera was achieved from the ten fungal plant pathogen isolates that gathered from different sites and regions in Taif region, Saudi Arabia. The identification of these organisms was conducted using molecular markers; among the identified species, 30% were Mucor circinelloides, 20% were Penicillium crustosum, and 20% were Alternaria alternata. The remaining 30% was comprised of Cladosporium tenuissimum, Phoma macrostoma, and Fusarium equiseti. A considerable proportion of these genera are widely acknowledged for their capacity to generate mycotoxins. The linear growth regression derived by the new plant extract is higher than fungicide, it has been found that the growth inhibition percentage driven by fungicide was between (20 to 85%), whereas for plant extract was between (80 to 100%) across all isolates. This data facilitate the contributing to the exploration of a more secure alternative to fungicides. Further, it will facilitate the development of regulatory approaches aimed at alleviating the detrimental consequences of fungal infections