A Combustion Tube Filling for the Determination of Carbon and Hydrogen in Fluorine Containing Compounds. I

Combustion tube fillings containing titanium dioxide, tin dioxide and thorium dioxide in combination with oxidation catalyst - Korbl catalyst or copper oxide - are applied for the microdetermination of carbon and hydrogen in organic fluorine compounds. Various samples of pure thorium dioxide and thorium dioxide on silica were examined and the measured retention capacities in mg fluorine per gram thorium dioxide are given. The capacity changes from 4.7 to 358 mg F/g Th02 depending on temperature and on the effective surface area of the thorium dioxide packing. A series of standards analyzed by this procedure had a standard deviation for carbon 0.230/o and for hydrogen 0.180/o. It has been found that thorium dioxide retains interfering combustion products containing fluorine but not those containing other halogens, sulphur or phosphor

Active rests during the work process

Svaki rad, osobito profesionalni, stvara umor koji smanjuje radnu učinkovitost. Aktivni odmori s izabranim rekreacijskim aktivnostima ugrađeni u proces rada vrlo su djelotvorni u uklanjanju simptoma umora. Članak iznosi primjere i mehanizme bržeg urađivanja i oporavka, koji su povezani s programiranom tjelesnom aktivnosti na početku rada, u vrijeme redovitih i/ili dodatnih odmora sukladno utvrđenom kritičnom vremenu u tijeku osmosatne radne smjene.Every work, especially professional work, induces fatigue whteh diminishes work efficacy. Active rests with aim-oriented recreational activities implemented in the work process are very efficacious in removing fatigue symptoms, The paper discusses examples and mechanisms of making work and recovery faster and more successful by programming physical activity at the beginning of work and during regular and added rests in accordance with the established critical time during the eight-hour work shift

Mossbauer Spectroscopy, X-ray Diffraction and IR Spectroscopy of Oxide Precipitates Formed from FeSO4 Solution

Iron oxyhydroxides and oxides were precipitated from FeS04 solution at low oxygen content. The composition and structure, stoichiometry, particle size and nuclear magnetism of the precipitates were studied using Mossbauer spectroscopy, X-ray diffraction and IR spectroscopy. The standard iron oxyhydroxides and oxides were also characterized using the same instrumental techniques. The results have indicated a strong dependence of the chemical composition and structure of the precipitates on the [FeS04] i [NaOH] concentration ratio. a-FeOOH of poor crystallinity was isolated at low pH values. a-Fe203 was formed by internal crystallization of a-FeOOH. At 90 aC, a mixture of Fe(OH)2iFe(OHh was transformed, with the time of heating, to nonstoichiometric Fe304, a-FeOOH and further to a-Fe203. Nonstoichiometric Fe304 was the final precipitation product in suspension with the [Fe2+]i [NaOH] stoichiometric ratio. The importance of these results for the corrosion science of steel in the presence of sulfates has been discussed

Testing the basic assumptions of the entrepreneurial orientation model on Croatian entrepreneurs

U posljednje se vrijeme u psihologijskoj literaturi može primijetiti sve veći interes za istraživanje poduzetništva. Malobrojna psihologijska istraživanja poduzetništva u Hrvatskoj dominantno su usmjerena na određivanje osobina poduzetnika, dok su istraživanja karakteristika organizacijske kulture i drugih organizacijskih procesa njihovih poduzeća u potpunosti zanemarena. Jedan od takvih konstrukata je poduzetnička orijentacija – fenomen koji se odnosi na procese i aktivnosti formiranja novih poslova, a uključuje pet osnovnih komponenti: inovativnost, proaktivnost, sklonost riziku, autonomiju i kompetitivnu agresivnost. S obzirom na to da postoje nalazi da je ona pod značajnim utjecajem okoline, valja provjeriti hoće li se ova struktura poduzetničke orijentacije replicirati i na uzorku hrvatskih poduzetnika. Stoga je svrha ovog istraživanja bila na uzorku hrvatskih poduzetnika provjeriti postavke 5-faktorskog modela poduzetničke orijentacije. Konfirmatorna faktorska analiza provedena na podacima prikupljenima u 252 mala i srednja hrvatska poduzeća potvrdila je pretpostavljenu multidimenzionalnu strukturu modela poduzetničke orijentacije. Dobiveni rezultati mogu poslužiti kao polazište za kreiranje intervencija s ciljem povećanja uspješnosti poslovanja hrvatskih malih i srednjih poduzeća.A growing interest for the field of entrepreneurship can be noticed in recent psychology literature. A few psychological studies of entrepreneurship in Croatia are predominantly focused on the characteristics of entrepreneurs, while the characteristics of organizational culture and other organizational processes remained completely ignored. One of these constructs is entrepreneurial orientation - a phenomenon that refers to the processes and activities of new businesses formation which includes five components: innovation, proactiveness, risk-taking, autonomy and competitive aggressiveness. Since many studies show that it is significantly influenced by the firm’s external environment, it should be verified whether the structure of entrepreneurial orientation will be replicated on a sample of Croatian entrepreneurs. Therefore, the purpose of this paper is to test the assumptions of the 5-factor entrepreneurial orientation model on a sample of Croatian entrepreneurs. Confirmatory factor analysis conducted on data collected for 252 small and medium sized enterprises in Croatia confirmed the hypothesized multidimensional structure of the entrepreneurial orientation model. The obtained results can provide a basis for interventions aiming to raise the performance of Croatian small and medium sized enterprises

Chronic obstructive lung disease in exposure to organic aerosols

Ispitivana je skupina radnica eksponiranih aerosolima pamuka, konoplje, lana, začina, soje, čajeva, kave te krzna. Aerosoli konoplje i lana uzrokovali su najveću prevalenciju kroničnih respiratornih simptoma i bolesti kao i najveće promjene ventilacijske funkcije pluća. U cilju prevencije potrebna je kontrola aerozagađenja kao i provođenje preventivnih medicinskih pregleda.A group of female workers occupationally exposed to cotton, hemp, flax, spices, soy, tea, coffee and furs was included in the study. The highest prevalence of chronic respiratory symptoms and diseases and greatest changes in ventilatory capacity were due to exposure to hemp and flax aerosols. The development of respiratory impairment can be impeded by control of the working environment and preventive medical examinations

Varicose veins of lower extremities in workers with jobs requiring continuous standing or sitting position

Epidemiološka ispitivanje učestalosti varikoznih vena donjih ekstremiteta izvršeno je u 779 industrijskih radnika (434 muškarca i 345 žena). Ispitivana je učestalost varikoznih vena u odnosu na stojeći odnosno sjedeći položaj pri radu. Utvrđena je statistički značajna (p < 0,05) povezanost između varikoznih vena i duljine zaposlenja u svih radnika osim u žena sa sjedećim položajem. Učestalost varikoznih vena povećavala se do 19 godina, a nakon toga je registriran pad (vjerojatno kao posljedica selekcije). Nije dobivena značajna razlika u učestalosti varikoznih vena donjih ekstremiteta između stojećeg i sjedećeg položaja pri radu.An epidemiological study of the prevalence of varicose veins of lower extremities was carried out in an industrial population of 434 men and 345 women. A statistically significant (p < 0.05) association between the varicose disease and duration of work was found in all groups of workers, except for women sitting at work. Decrease in the prevalence of varicose veins after 20 years of employment may be explained at least partly, by the factor of selfselection in the industry. However, there was no difference in the prevalence of varicose veins between workers standing and those sitting at work

Ventilatory capacity and intradermal skin tests in cotton workers

Kronični respiratorni simptomi, respiratorne bolesti, ventilacijske funkcije i alergijski kožni testovi promatrani su u skupini od 112 radnika zaposlenih u preradi pamuka. Učestalost pojave kroničnih respiratornih simptoma i bolesti bila je veća u eksponiranih nego u radnika kontrolne skupine premda su razlike bile statistički značajne samo za kronični kašalj, katar nosa i bisinozu u žena te za kronični kašalj, kronični iskašljaj i bisinozu u muškaraca. Bisinoza je registrirana u sličnoj prevalenciji u žena (29,4%) i u muškaraca (29,5%). U ispitivanih tekstilnih radnika pretežno se radilo o bisinozi stupnja 1/2 (žene 22,1 %, muškarci 20,5%). Rezultati ventilacijskih testova pokazuju tijekom radne smjene statistički značajne akutne redukcije forsiranog vitalnog kapaciteta (FVK) i forsiranog ekspiratornog volumena u prvoj sekundi (FEV1). U muškaraca su utvrđene nešto niže izmjerene vrijednosti testova u odnosu na normalne očekivane vrijednosti. Mali broj radnika reagirao je na alergen pamuka (eksponirani 8,2%, kontrola 1,8%). Naši rezultati pokazuju da ekspozicija prašini pamuka može dovesti do pojave respiratornih simptoma i bolesti te do akutnih promjena funkcionalnih testova ventilacije, ali bez alergijske reakcije.Ventilatory capacity, chronic respiratory symptoms and respiratory diseases as well as intradermal skin tests were registered in a group of 112 cotton workers. The prevalence of chronic respiratory symptoms and respiratory diseases was higher among the exposed than among control workers although the differences were statistically significant only for chronic cough, nasal catarrh and byssinosis in women and for chronic cough, chronic phlegm and byssinosis in men. A similar prevalence of byssinosis was noted in women (29.4%) and in men (29.5%). Among textile workers mostly byssinosis grade 1/2 was found (women 22.l %, men 20.5%). There were statistically significant acute reductions over work shift for forced vital capacity (FVC) and one-second forced expiratory volume (FEV1). In men the values were somewhat lower than the expected normal values. A very small number of workers demonstrated positive intradermal skin tests to cotton allergen (exposed 8.2%, control 1.8%). Our data indicate that exposure to cotton dust may lead to the development of respiratory symptoms and diseases as well as to acute changes in ventilatory capacity but without an allergic reaction

Respiratory and immunological changes in tea workers

Respiratorna funkcija ispitivana je u 100 radnica zaposlenih u preradi čajeva (gruzijski, kadulja, šipak, indijski i kamilica) i u 84 radnice kontrolne skupine. Prevalencija većine kroničnih respiratornih simptoma bila je značajno viša u radnica pri preradi šipka, kadulje i gruzijskog čaja nego u radnica kontrolne skupine. Tijekom radne smjene utvrđene su statistički značajne srednje akutne redukcije za maksimalni ekspiratorni protok pri 50% i 25 % vitalnog kapaciteta na krivulji maksimalnog ekspiracijskog protoka i volumena (FEF50: 4,1-8,8%; FEF25: 7,8-21,8%) u svih osim u radnica izloženih kamilici. Akutne redukcije FEV1 bile su mnogo manje i uglavnom statistički neznačajne. Imunološki status ispitivan je u 26 radnica u preradi čajeva i u 17 radnica kontrolne skupine. Intradermalni testovi s alergenima čajeva pokazivali su najveći postotak pozitivnih kožnih reakcija na kadulju (45%), gruzijski čaj (40%) i šipak (10%). U kontrolnoj skupini radnica utvrđene su pozitivne kožne reakcije u 23 % na kadulju, 19 % na gruzijski čaj i 11 % na šipak i indijski čaj. Koncentracija IgE u serumu povišena je u 27% radnica u preradi čajeva i u 7% radnica kontrolne skupine.Respiratory function was examined in 100 female workers employed in the production of different types of tea (gruzyan, sage, dog rose, indian and chamomile) and in 84 female control workers. The prevalence of almost all chronic respiratory symptoms was significantly higher in workers processing dog rose, sage and gruzyan tea than in the control group. During work shift there were significant mean acute reductions in maximal expiratory flow rates at 50% and 25 % of the vital capacity on maximum expiratory flow-volume curves (FEF50: 4.l-8.8%;FEF25: 7.8-21.8%) except in workers exposed to chamomile. Acute reductions in FEY1 were considerably smaller and not significant. The immunological status was examined in 26 tea workers and in 17 control workers. Skin tests with tea allergens demonstrated the highest percentage of positive reaction to sage (45%), gruzyan tea (40%) and dog rose (10%). Among the control workers, 23% had a positive skin reaction to sage, 19 % to gruzyan tea and 11 % to dog rose and indian tea. Serum levels of total IgE were elevated in 27 % of the tea workers and in 17% of the control subjects