Bus Drivers Whole-body Vibration Exposure, Evaluation Procedures, Prevention and Control

Public transport bus drivers are exposed to a wide range of hazards which can endanger their occupational safety and health. Risks of possible traffic accidents, stress (due to traffic jams, pace of work, conflicts with passengers and other road users, etc.), fatigue, long sitting hours, vibration, noise, exposure to air pollution, adverse microclimatic conditions are just some of the factors that can endanger a driver’s health and are characterized by a different likelihood of occurrence and consequence severity. Whole-body vibration transferred to human over many years of exposure have the potential to endanger health with respect to the onset of musculoskeletal disorders, especially in synergy with prolonged sitting. In addition, whole-body vibration exposure is a possible source of discomfort, which, combined with other factors, can contribute to the negative effect on the general physical and mental state of the driver, and therefore the occurrence of fatigue and stress.In order to manage the exposure of bus drivers to vibration, it is necessary to evaluate the exposure, using methodologies defined by international standards, based on expert analysis and measurements. The paper presents the dominant health risks arising from the whole-body vibration of professional bus drivers, the parameters of exposure evaluation, measurements and evaluation procedure in accordance with European Directive 2002/44/EC and ISO standards, as well as an overview of the precautions to be taken in to reduce the risk associated with bus drivers occupational whole-body vibration exposure

Safety factors in wall thickness calculation of rectification columns

Kolone za rektifikaciju gasa veoma su važan deo svake fabrike. Njihovi iznenadni otkazi svakodnevno uzrokuju ogromne gubitke, dok curenje tečnosti može biti veoma opasno po ljude i životnu sredinu. Iz tog razloga, pravilan dizajn kolone je od velike važnosti, kao i primena ostalih faktora bezbednosti. U ovom radu prikazano je merenje debljine zida sa ciljem da se izračuna stopa korozije i preostali vek trajanja rektifikacionih kolona. Minimalna potrebna debljina zida kolone izračunata je prema najčešće korišćenim međunarodnim standardima i analizirana je dobijena razlika.Gas rectification columns are a very important part of each onshore plant. Their sudden failures cause huge losses on a daily basis, while fluid leakage can be very dangerous to people and environment. For that reason, the proper design of the column is of huge importance, among the others safety factors as well. In this paper, the wall thickness measure is presented with the aim to calculate corrosion rate and remaining life of rectification columns. The minimum required column wall thickness was calculated according to the most commonly used international standard and the obtained difference was analyzed

Safety factors in wall thickness calculation of rectification columns

Kolone za rektifikaciju gasa veoma su važan deo svake fabrike. Njihovi iznenadni otkazi svakodnevno uzrokuju ogromne gubitke, dok curenje tečnosti može biti veoma opasno po ljude i životnu sredinu. Iz tog razloga, pravilan dizajn kolone je od velike važnosti, kao i primena ostalih faktora bezbednosti. U ovom radu prikazano je merenje debljine zida sa ciljem da se izračuna stopa korozije i preostali vek trajanja rektifikacionih kolona. Minimalna potrebna debljina zida kolone izračunata je prema najčešće korišćenim međunarodnim standardima i analizirana je dobijena razlika.Gas rectification columns are a very important part of each onshore plant. Their sudden failures cause huge losses on a daily basis, while fluid leakage can be very dangerous to people and environment. For that reason, the proper design of the column is of huge importance, among the others safety factors as well. In this paper, the wall thickness measure is presented with the aim to calculate corrosion rate and remaining life of rectification columns. The minimum required column wall thickness was calculated according to the most commonly used international standard and the obtained difference was analyzed

A study of aerodynamic noise in air duct systems with turning vanes

Buka je jedan od problema u mnogim industrijama. U ovom radu prikazana je analiza aerodinamički nastale buke koja se javlja pri strujanjima vazduha preko usmerivača vazduha oblika aeroprofila u vazdušnim kanalima. Na osnovu Proudmanove jednačine i Lajthilove akustične analogije širokopojasni nivo buke u vazdušnom kanalu može biti izračunat. Za modeliranje turbulentnog modela, k - e turbulentni model je korišćen a potrebne konstante su eksperimentalno određene merenjem u aerotunelu za podzvučne brzine, nakon kojih su vršena merenja buke za u neposrednoj blizini usmerivača vazduha oblika aeroprofila. Nekoliko rešenja je analizirano, kanal sa unutrašnjim aeroprofilom, kanal sa centralnim aeroprofilom, kanal sa spoljašnjim aeroprofilom kao i kombinacija prethodnih slučajeva. Analizom dobijenih rezultata, a u cilju ispunjavanja svih zakonskih propisa koji se tiču industrijske buke, koji postaju sve striktniji, akustična analiza i projektovanje moraju biti primenjeni u većini industrijskih sistema jer buka predstavlja opasnost po zdravlje radnika u radnom okruženju.Noise is becoming one of the problems in many industrial applications. In this paper the aerodynamic noise in air duct system that arises from air flow passing over a surface of turning vanes is investigated. Based on Proudman's formula using Lighthill's acoustic analogy broadband acoustic noise model can be predicted. To model the turbulent flow in an air duct k - e turbulent model is used and required constants are obtained experimentally in a low speed wind tunnel followed by noise measurement in the vicinity of deflected airfoil. Several designs are investigated: Inner airfoil in the duct elbow, center positioned air foil, outer positioned and the overall combination of all previous cases. It was found that in order to satisfy all noise requirements and regulation, which are becoming more strict nowadays, the acoustic analysis and design must be performed in most industrial systems since the noise levels arising from the operating industrial equipment may represent occupational and health hazard

A study of aerodynamic noise in air duct systems with turning vanes

Buka je jedan od problema u mnogim industrijama. U ovom radu prikazana je analiza aerodinamički nastale buke koja se javlja pri strujanjima vazduha preko usmerivača vazduha oblika aeroprofila u vazdušnim kanalima. Na osnovu Proudmanove jednačine i Lajthilove akustične analogije širokopojasni nivo buke u vazdušnom kanalu može biti izračunat. Za modeliranje turbulentnog modela, k - e turbulentni model je korišćen a potrebne konstante su eksperimentalno određene merenjem u aerotunelu za podzvučne brzine, nakon kojih su vršena merenja buke za u neposrednoj blizini usmerivača vazduha oblika aeroprofila. Nekoliko rešenja je analizirano, kanal sa unutrašnjim aeroprofilom, kanal sa centralnim aeroprofilom, kanal sa spoljašnjim aeroprofilom kao i kombinacija prethodnih slučajeva. Analizom dobijenih rezultata, a u cilju ispunjavanja svih zakonskih propisa koji se tiču industrijske buke, koji postaju sve striktniji, akustična analiza i projektovanje moraju biti primenjeni u većini industrijskih sistema jer buka predstavlja opasnost po zdravlje radnika u radnom okruženju.Noise is becoming one of the problems in many industrial applications. In this paper the aerodynamic noise in air duct system that arises from air flow passing over a surface of turning vanes is investigated. Based on Proudman's formula using Lighthill's acoustic analogy broadband acoustic noise model can be predicted. To model the turbulent flow in an air duct k - e turbulent model is used and required constants are obtained experimentally in a low speed wind tunnel followed by noise measurement in the vicinity of deflected airfoil. Several designs are investigated: Inner airfoil in the duct elbow, center positioned air foil, outer positioned and the overall combination of all previous cases. It was found that in order to satisfy all noise requirements and regulation, which are becoming more strict nowadays, the acoustic analysis and design must be performed in most industrial systems since the noise levels arising from the operating industrial equipment may represent occupational and health hazard

Vibrational and magnetic properties of nano-sized CoFe2O4 obtained by various synthesis techniques: a comparative study

Nanocrystalline CoFe2O4 has been synthesized by various synthesis methods. The obtained monodomain nanoparticles are similar in sizes (15.8-19 nm), but with different internal stresses, size distributions and cation inversion coefficients (0.51 - 0.90) due to different synthesis routes. The structure and cation distribution are investigated by XRD diffraction analysis, Raman and FIR spectroscopy. Measurement of magnetization, i.e. coercivity, enable the calculation of the anisotropy coefficient K1 = (3.6-5.12)·105 J cm-3, which is very high in cobalt ferrite. The anisotropy coefficient directly depends on the nanoparticle size. It has been shown that magnetization linearly depends on the cation inversion, except in the sample with the largest nanoparticles (19 nm), where the more regular crystal structure prevails and higher values of magnetization were obtained. The average magnetic moments at 300 K are: μFe = 3.6μB and μCo = 2.5μB. It is obvious that with small adjustments in the synthesis, desirable nanoparticle properties can be obtained

Menadžment znanja i upravljanje inovacijama kao izvor poslovnog uspeha i konkurentske prednosti preduzeća

Novo stanje društva zasnovano je na sposobnosti da se stvori novo znanje i da se kroz inovacije proizvoda, usluga i procesa, transformiše u ekonomsku vrednost i bogatstvo. Upravljanje znanjem predstavlja jedan od najefikasnijih načina za poboljšanje rezultata poslovanja u organizacijama.Takođe potrebno je povećati i stimulisati inovacije kako bi se održao korak sa konkurencijom. U radu se bavimo analizom ova dva koncepta upravljanja: znanjem i inovacijama. Dinamičnost oba faktora je nesumnjiva. Sve više se govori ne o menadžmentu znanja već o razvoju znanja. S druge strane svaka inovacija već momentom njene primene počinje da zastareva. Pored aktuelnosti ova tematika je zasnovana na povezanosti između znanja i veštine da se uoče mogućnosti i kreiraju novi načini da se te mogućnosti iskoriste kroz inovacione procese. Krajnji cilj ove implementacije je poslovni uspeh, odnosno konkrentska prednost

In silico–in vitro estimation of lipophilicity and permeability association for succinimide derivatives using chromatographic anisotropic systems and parallel artificial membrane permeability assay

Passive permeability is one of the key features that determine absorbability and one of the most studied properties in the early phases of drug development. Newly synthesized succinimide derivatives from two different series (1-aryl-3-methylsuccinimides and 1-aryl-3-ethyl-3-methylsuccinimides) with high biological potential have been subjected to estimation of their passive permeability and their association with (a) experimentally obtained anisotropic lipophilicity, (b) in silico–calculated lipophilicity and (c) in silico–predicted permeability and absorbability. Non-cellular-based parallel artificial membrane permeability assay was applied for quantifying their passive permeation, expressed as logPapp. Passive permeation was governed by the lipophilicity of the analysed compounds, and anisotropic lipophilicity was related with statistically significant passive transcellular diffusion (r2 = 0.614, P < 0.001). Moreover, experimentally determined passive permeability, logPapp, was statistically significantly associated with both in silico–predicted absorption constant, ka (r2 = 0.7886, P < 0.001), and human intestinal absorption (HIA) in percentage (r2 = 0.484, P < 0.001), respectively. However, there was no statistically significant relationship between experimentally obtained permeability on non-cellular-based model and in silico–predicted Caco-2 permeability based on the predictions conducted on two different software. Based on the obtained results, anisotropic systems are promising surrogates for determining lipophilicity, except for compounds with acidic functional groups that are completely ionized under (pH = 7.4)

In silico–in vitro estimation of lipophilicity and permeability association for succinimide derivatives using chromatographic anisotropic systems and parallel artificial membrane permeability assay

Passive permeability is one of the key features that determine absorbability and one of the most studied properties in the early phases of drug development. Newly synthesized succinimide derivatives from two different series (1-aryl-3-methylsuccinimides and 1-aryl-3-ethyl-3-methylsuccinimides) with high biological potential have been subjected to estimation of their passive permeability and their association with (a) experimentally obtained anisotropic lipophilicity, (b) in silico–calculated lipophilicity and (c) in silico–predicted permeability and absorbability. Non-cellular-based parallel artificial membrane permeability assay was applied for quantifying their passive permeation, expressed as logPapp. Passive permeation was governed by the lipophilicity of the analysed compounds, and anisotropic lipophilicity was related with statistically significant passive transcellular diffusion (r2 = 0.614, P < 0.001). Moreover, experimentally determined passive permeability, logPapp, was statistically significantly associated with both in silico–predicted absorption constant, ka (r2 = 0.7886, P < 0.001), and human intestinal absorption (HIA) in percentage (r2 = 0.484, P < 0.001), respectively. However, there was no statistically significant relationship between experimentally obtained permeability on non-cellular-based model and in silico–predicted Caco-2 permeability based on the predictions conducted on two different software. Based on the obtained results, anisotropic systems are promising surrogates for determining lipophilicity, except for compounds with acidic functional groups that are completely ionized under (pH = 7.4)

Semi-kvantitativna analiza za procenu održive proizvodnje zelenog vodonika gasifikacijom biomase

One of the goals that mankind has set for 2050 is decarbonization in the energy sector. For thatreason, the use of hydrogen as an alternative fuel looks like a possible solution. However, the conventionalhydrogen production process (electrolysis) now indirectly accounts for more than 2% oftotal global CO2 emissions. One of the scenarios to reaching set targets involves the decarbonizationof hydrogen production, resulting in green hydrogen. The one of the pathways for production of greenhydrogen is feasible within the gasification of lignocellulosic materials (biomass feedstock) into syngas.However, different feedstock parameters have an impact on the thermochemical conversion processi.e. syngas yield and composition. This paper presents the novel semi-quantitative analysis offundamental experimental data obtained by thermogravimetry and mass spectrometry. According tothe proposed methodology on the lab-scale level is possible to evaluate the feedstock quality for identificationof syngas yield and composition, with special attention to the hydrogen content in the syngas.The experimental results for two biomass samples were presented and based on performed semiquantitativeanalysis the evaluating of the possibilities for using considered feedstocks for green hydrogenproduction was done. Further discussions and comparisons with literature data were alsopresented.Jedan od ciljeva koje je čovečanstvo postavilo do 2050. godine je dekarbonizacija u energetskom sektoru. Iz tog razloga upotreba vodonika kao alternativnog goriva izgleda kao moguće rešenje. Međutim, konvencionalni proces proizvodnje vodonika (elektroliza) sada indirektno čini više od 2% ukupne globalne emisije CO2. Jedan od scenarija za dostizanje postavljenih ciljeva uključuje dekarbonizaciju proizvodnje vodonika, što rezultira zelenim vodonikom. Jedan od načina za proizvodnju zelenog vodonika je moguć putem gasifikacije lignoceluloznih materijala (biomasa kao sirovina) u sintetički gas. Međutim, različiti parametri sirovine utiču na proces termohemijske konverzije, odnosno prinos i sastav sintetičkog gasa. Ovaj rad prezentuje novu semi-kvantitativnu analizu eksperimentalnih podataka dobijenih fundamentalnim eksperimne-talnim tehnikama, termogravimetrijom i masenom spektrometrijom. Prema predloženoj metodologiji na laboratorijskom nivou moguće je proceniti kvalitet sirovine za identifikaciju prinosa i sastava sintetičkog gasa, sa posebnom pažnjom na sadržaj vodonika u sintetičkom gasu. Predstavljeni su eksperimentalni rezultati za dva uzorka biomase i na osnovu izvršene semi-kvantitativne analize procenjena je mogućnostkorišćenja razmatranih sirovina za proizvodnju zelenog vodonika. Takođe je izvršena detaljna diskusija dobijenih rezultata kao i prikazana poređenja sa podacima iz lite-rature.