Procjena utjecaja modernizacije i novih tehnoloških procesa na izloženost buci u aluminijskoj industriji

The aim of this study was to assess to which extent modernisation of an aluminium production complex reduced occupational noise hazard for jobs with the highest potential of exposure. Periodical measurements of noise level were taken at the same workplaces using the same method, before and after modernisation of all plants. The results were compared with the recommended standard. After modernisation, the noise was significantly reduced in all sections of all plants. The greatest reduction was measured in the foundry. After modernisation, the portion of workplaces with excessive noise level dropped significantly (chi-square=21.315; p<0.0001) from 78.4 % to 13 %. Noise remained a problem in ingot casting and dross skimming section. In the anode plant, noise remained a problem in the green mill section where noise intensities generated by mills and vibrocompactors varied from 95 dB(A) to 102 dB(A). In the electrolysis plant, the portion of workplaces with extensive noise dropped from 77.8 % to 39.3 % after modernisation (p=0.0019). Noise remains to be a problem at the anode covering section where levels rise up to 100 dB(A). The modernisation of the factory has considerably reduced the noise level in the working environment of all plants, but it can not be reduced completely.Cilj je rada procijeniti utjecaj modernizacije tehnološkog procesa proizvodnje aluminija na prisutnost i razinu buke štetne za zdravlje radnika u radnom okolišu. U tu svrhu uspoređivani su rezultati periodičkih mjerenja razine buke prije i nakon modernizacije. Mjerenja intenziteta buke provedena su na istim radnim mjestima i istom metodom tijekom radnih smjena i uspoređeni s važećim nacionalnim standardom. Nakon modernizacije tvornice u svim odjelima proizvodnih pogona značajno se smanjila razina buke, kao i broj radnih mjesta na kojima su radnici izloženi prekomjernoj buci. Najbolji rezultati postignuti su u ljevaonici, gdje se broj radnih mjesta s prekomjernom razinom buke, tj. razinom buke višom od 90 dB(A) smanjio sa 78.4 % na 13 %. Na radnim mjestima gdje se izlijevaju ingoti i skida šljaka buka je i dalje prekomjerna. U pogonu anoda prekomjerna je buka i dalje prisutna pri proizvodnji sirovih anoda, gdje razina buke zbog rada mlinova i vibrokompresora varira od 95 dB(A) do 102 dB(A). U pogonu elektrolize buka viša od 100 dB(A) izmjerena je pri zasipanju anoda. Iako je modernizacijom tvornice i unaprjeđenjem tehnološkog procesa značajno reducirana razina buke, nije ju moguće u cijelosti ukloniti

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza a(H1N1)pdm09 and B among elderly people in Europe: Results from the I-MOVE+ project

We conducted a multicentre test-negative caseâ\u80\u93control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged â\u89¥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases

USE OF HIGH SURFACE NANOFIBROUS MATERIALS IN MEDICINE

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Hydrogen permeation through disordered nanostructured tungsten films

We report results on long-term hydrogen outgassing and permeation studies of structurally highly disordered tungsten films, deposited on 40 mm diameter highly permeable Eurofer substrates, using the Pulsed Laser Deposition technique. Hydrogen interaction with tungsten is becoming a highly relevant topic since tungsten was recognized as the most promising candidate for the first wall of future fusion reactors. Prediction of hydrogen isotopes migration and their abundance after plasma exposure is uncertain due to a great role played by structural disorder that is formed on the W surface. Vacancy sites are theoretically predicted to trap multiple H atoms exothermically, but their density and their potential influence on permeability has not been experimentally investigated yet. In our work, permeability of W films having different thicknesses (1 and 10 micron) was initially extremely low, and was gradually increasing over a several-day campaign. The final values at 400 °C, lying between P = 1.46 1E15 mol H2/(m s Pa^0.5) and P = 4.8 1E15 mol H2/(m s Pa^0.5), were substantially lower than those known for well ordered films. Surprisingly, the 10 micron thick W film initially contained a very high amount of hydrogen, 0.1 H/W, which was gradually releasing during the twenty-day campaign

Building a unique test section for local critical heat flux studies in light water reactor like accident conditions

Critical heat flux (CHF) has been studied for almost a century and yet there is no indisputable consensus reached on governing physical phenomena behind, not to mention, on modelling agreement of different correlations. When we are compelled to run our system at the safe distance from the CHF, and we can use all the accumulated knowledge so far, we will quite possibly cling to look-up tables delivered with that particular system. If this is not the case, than we will certainly stick to the system-specific correlation, which cannot be applied with confidence elsewhere. In the last two decades there were significant advancements applied both in numerical simulation capabilities and in unintrusive measuring techniques, which shed light on anticipated advancements in modelling the phenomenon. However, there are few reliable experimental measurements of instantaneous velocity and temperature fields in the wall boundary layer, and they are nil where local heat transfer coefficients are acquired. Therefore, at Reactor Engineering Division of Jožef Stefan Institute, a unique test section for local critical heat flux studies is under construction. The selected geometry and the test conditions will resemble light water reactor – like accident conditions. Moreover, to understand the phenomenon better, the design of the test section enables local measurements of heat transfer coefficients, and allows for control over the diabatic wall temperature. Measurements of single-phase convective heat transfer, conjugate heat transfer, flow boiling, convective condensation, and condensation-induced liquid hammer were all part of the test section’s design basis. In this context, the design and construction of the device is herein presented in considerable detail.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers