Zaštita na radu u medicinskom laboratoriju i izloženost formaldehidu

Chemical hazards in their various forms deteriorate the quality of air in the work environment. The way of introduction of toxicants into the human body and the transformation pathways are the main factors that influence the realization of harmful effects. Due to the high prevalence in various industries, the attention of occupational professionals working in the quality of the working environment has been directed towards formaldehyde, over the last decades. The paper presents the essential characteristics of formaldehyde and the health effects caused by exposure to different concentration levels of this hazard. Emphasis is put on employees in medical laboratories where formaldehyde is used as a disinfectant and agent for the conservation of specimens in anatomy laboratories. The experimental part of the work was carried out in the laboratories of the Department of Anatomy, where FA concentration levels were monitored in different rooms to evaluate the exposure of employees.SAŽETAK: Opasne kemijske tvari u raznim oblicima narušavaju kakvoću zraka u radnoj okolini. Način unošenja otrovnih tvari u ljudsko tijelo i transformacijski putovi glavni su čimbenici štetnih učinaka. Zbog velike raširenosti formaldehida u mnogim industrijama već nekoliko desetljeća pozornost stručnjaka zaštite na radu usmjerena je na taj fenomen. Studija prikazuje temeljne karakteristike formaldehida i učinke na zdravlje prouzročene izlaganjem različitim koncentracijama te opasne tvari. Težište je na zaposlenima u medicinskim laboratorijima gdje se formaldehid koristi kao sredstvo za dezinfekciju i agens za čuvanje uzoraka tkiva u anatomskim laboratorijima. Eksperimentalni dio studije odrađen je u laboratorijima Odjela za anatomiju, a razine koncentracije formaldehida praćene su u različitim prostorijama kako bi se utvrdila izloženost zaposlenika

Detection model of benzene, toluene, ethylbenzene and xylene in exhaust gases of motor vehicles by using gas chromatography in evaluating of ambient air pollution

U okviru doktorske disertacije opisane su jedinstvene fiziĉko-hemijske karakteristike grupe supstanci benzena, toluena, etilbenzena i ksilena koje pripadaju istraživanjima najnovijeg trenda nauĉne javnosti. Posebno su opisane perzistencija i pseudoperzistencija, transport, distribucija i negativan i toksiĉan uticaj na zdravlje ĉoveka i životnu sredinu. Sprovedena su eksperimentalna istraživanja zavisnosti koncentracionih nivoa BTEX jedinjenja u izduvnim gasovima i operativnih parametara eksperimentalnog motora SUS. Na osnovu dobijenih rezultata eksperimentalnih istraživanja definisan je emisioni model BTEX jedinjenja simulacijom kretanja putniĉkog automobila Fiat Punto Classic u skladu sa NEDC ciklusom koji na odgovarajući naĉin reprezentuje standarde uslove vožnje u evropskim gradovima.In this thesis, the unique physicochemical characteristics of a group of substances consisting of benzene, toluene, ethylbenzene and xylene have been described. Special emphasis has been placed on their characteristics of persistence and pseudopersistence, transport, distribution and the negative and toxic influence on human health and the environment. The experimental research of the interdependence of the concentration levels of BTEX compounds in the exhaust gases and the operational parameters of the experimental IC engine has been conducted. Based on the experimental research results, the emission model of the BTEX compounds has been defined by a simulation of movement of a Fiat Punto Classic passenger car in accordance with the NEDC cycle, which appropriately represents the standard driving conditions in European cities. Research conducted within the thesis represents the newest trend of investigation in the scientific world

Emissions of total volatile organic compounds during the digital printing process

The impact of the type of digital machine on increasing of total volatile organic compounds (TVOCs) in the ambient air of the digital printing office was analysed in this study. For that purpose, the TVOCs concentrations in gas samples were measured by mobile gas chromatograph Voyager-Photovac. The cumulative concentrations values of TVOCs for the single-color digital machine were in the range from 0.56 to 5.90 ppm and almost 4 and 25 times below compared to the same values for the four-color digital machine (14.01 - 24.84 ppm). The obtained results could be useful for the future risk assessment of indoor exposure of TVOCs, and for the creation of printing indoor air quality guidelines of the Republic of Serbia

Disadvantages of electrocoagulation-flotation treatment of offset printing effluents

The efficiency of electrocoagulation-flotation (ECF) treatment was estimated based on the quantity of pollutants (cooper, turbidity, and organic substances) in printing effluents (waste offset printing developer and waste offset fountain solution) at selected process parameters. Four sets of aluminum or/and iron electrode combinations were applied, each with a current density of 2, 4, and 8 mA cm−2 and interelectrode distances of 0.5, 1.0, and 1.5 cm. In the progress of the ECF treatment, samples were taken at certain process times (1, 5, 10, 20, 40, and 60 min). Based on the obtained results, the disadvantages of ECF treatment of offset printing effluents are defined

Electrocoagulation removal of heavy metals from wastewater generated by washing a screen printing plate

The possibility of applying electrocoagulation treatment to remove heavy metals (zinc, copper, and chromium) from wastewater generated during the washing process of the screen printing plate was carried out. The electrocoagulation efficiency is estimated based on reducing the concentrations of detected heavy metals in the screen wastewater at defined process parameters such as electrode material, current density, interelectrode distance, and operating times

Utjecaj promjenjivog kontaktnog tlaka i promjenljive visine zateznog rebra na duboko vučenje limova od Al legura

The process of deep drawing is influenced by many factors. During the forming process, only two of those factors can be controlled. They are blank holding force and drawbead height. Realisation of such control requires relatively complex computerized apparatus. For this experimental research, electro-hydraulic sheet-metal strip sliding device has been constructed. Basic capacity of realized device is obtaining contact pressure and drawbead height as functions of time or stripe displacement. Additional features consist of the ability to measure drawing force, contact pressure, drawbead displacement etc. Presented in the paper are the results of influencing of increasing and decreasing drawbead height functions in combination with increasing-decreasing function of contact pressure. Stripe material is aluminium alloy AlMg4,5Mn0,7 sheet metal. Contact condition are additionally influenced by application of mineral oil or completely dry tool and stripe surfaces. Drawbead geometry, with rounding radii of 2 and 5 mm, is also varied. The accomplished results indicate that simultaneous effects of variable drawbead height, variable contact pressure, tool geometry and appropriate friction conditions can influence the plastic flow process in line with desired change of forming force.Na proces dubokog vučenja utječe više faktora. Tijekom trajanja procesa oblikovanja moguće je upravljati samo s dva faktora. To su sila držanja i visina zateznog (vlačnog) rebra. Ostvarivanje takvog upravljanja zahtjeva relativno složenu kompjutoriziranu aparaturu. Za ovo pokusno istraživanje razvijen je elektro-hidraulički uređaj za klizanje traka od lima s kompjutorskim upravljanjem. Njegova osnovna karakteristika je ostvarivanje kontaktnog tlaka i visine zateznog rebra, kao funkcijskih ovisnosti o vremenu, odnosno hodu trake. Pored toga, moguće je mjeriti vučnu silu, silu pritiska, pomak rebra itd. U radu su izloženi rezultati ispitivanja utjecaja opadajuće i rastuće ovisnosti visine rebra u kombinaciji s rastuće-opadajućom funkcijom kontaktnog tlaka. Materijal trake je legura aluminija AlMg4,5Mn0,7 debljine 0,9 mm. Na kontaktne uvjete se dopunski utječe s dva tipa trenja. U prvom slučaju površine su suhe, a u drugom se primjenjuje podmazivanje odgovarajućim mineralnim uljem. Geometrija rebra se mijenja preko polumjera zaobljenja 2 i 5 mm. Ostvareni rezultati pokusa pokazuju istodobno djelovanje promjenljive visine rebra, promjenljivog kontaktnog tlaka, geometrije rebra i odgovarajućih uvjeta trenja, mogu utjecati na proces plastičnog tečenja u skladu sa željenom promjenom sile oblikovanja

Information systems in small and medium-sized enterprises of the textile and clothing industry

Market uncertainty and financial instability in the era of global competition force companies to work faster and increase productivity and business efficiency with continuous cost reduction and qualitative efficiency, which serves as a basis for strengthening the competitiveness and sustainable development of all, including SMEs -small and medium-sized enterprises of the textile and clothing industry. Various innovative contents and adequate technological solutions, as well as reengineering of business/production processes, with massive and adequate implementation of technical-technological innovations based on information and communication technologies -ICT and flexible automation, i.e. on the direct and efficient implementation sector defined information systems, also represent possible elements of functional competitiveness and sustainable development. Otherwise, changes in the environment and ways of doing business of companies require a better understanding and integration of data, as well as their more efficient exploitation in the functioning and development of the company, which imposes the need for permanent generation, adaptation and development of quality and efficient information systems. As a result of such requirements, the responses of industrial production through the implementation of technical-technological innovations are inevitable, whereby quality and efficient ICT infrastructure, coherence of innovative technologies and flexible production, as well as compatibility and complementarity of production and business information systems, are necessary elements and indicators of efficiency and quality. The implementation, efficient exploitation, as well as the development of various business and production information systems, obviously has its benefits, presented through more efficient, better quality and faster operations, but also disadvantages, because it is obviously conditioned by the stochastic laws of the global market, the variable human factor or the lack of high-quality, highly educated professionals staff, requirements for high initial investments, but also the specifics of the textile/clothing industry and SMEs, as well as the incompatibility of the implemented production and business systems

The heavy metals in the processing screen printing inks

The contents of heavy metals were analyzed in the two types (solvent-based and water-based) of processing screen printing inks. Mass concentrations of heavy metals (copper, iron, zinc, manganese, chromium, nickel, cadmium, and lead) were determined in the tested screen inks by combining the gravimetric method and atomic absorption spectroscopy. The results indicated that the measured mass concentration of copper (2049.9 mg kg-1 ) in solvent-based cyan ink is 2.4 times higher than in water-based cyan. Other detected metals show higher concentration values with water-based processing inks

Analiza DNA u sudskoj medicini i njezina primjena u hrvatskome kaznenopravnom sustavu

U izlaganju se daje kratak pregled tijeka razvoja istraživanja DNA kao “novog znanstvenog dokaza” odnosno odgovora znanosti na sve profesionalniji pristup počinitelja u planiranju počinjenja te prikrivanju tragova kaznenog djela i potrebu očuvanja najvažnijih vrijednosti svake pravne države. Posebno se iznose novine vezane uz DNA analizu bioloških materijala i DNA baze podataka kroz novi Zakon o kaznenom postupku. Također, izlaganje prikazuje nastojanje da se prvi put u hrvatskome kaznenopravnom sustavu omogući izuzimanje biološkog materijala, radi provođenja DNA analize, od pravomoćno osuđenih osoba koje se nalaze na izdržavanju kazne zatvora, i to kroz predložene izmjene Zakona o izvršavanju kazne zatvora, koje su trenutno u saborskoj proceduri

Experimental and Numerical Analyses of the Temperature Field in the Ironing Process

The purpose of this paper is to determine the temperature fields in the workpiece and the tool in the ironing process using an integrated approach that includes laboratory experiments and numerical modelling. An originally developed model device for ironing sheet metal strips, which was previously shaped by U-bending, was used for the experimental research. Thermocouples were installed in the device at the position close to the contact surface with the workpiece. The device was mounted on a hydraulic press that enables maximum ironing speeds of v = 4,17 mm/s. In order to determine the temperature fields at higher ironing speeds, a series of numerical experiments was performed at identical speeds as in the experiments (0,33 mm/s and 4,17 mm/s) and at higher speeds (100 mm/s, 1000 mm/s and 10000 mm/s). Good matches of the experimental and numerical results at lower speeds were obtained, so the numerical estimates at higher speeds were valid for the analysis and conclusions. With the increase of the ironing speed, a trend of temperature increase is evident. The maximum temperature of 166 °C at ironing speed of 10000 mm/s that corresponds to manufacturing of 250 cans per minute is significantly lower than the critical melting temperature of the tin coating