Wyniki wyszukiwania - Biblioteka Nauki

1

Żelazo jako pierwiastek niezbędny do funkcjonowania organizmów żywych

100%

Kurek E. , Bulska E.

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2008

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tom nr 1

79-82

2

Koncentracja zanieczyszczeń metalicznych w oleju silnikowym na przykładzie silnika o zapłonie samoczynnym

84%

Chmielewski Z. , Niewczas A.

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2000

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tom nr 2(5)

56-59

PL

W artykule przedstawiono wyniki badań zawartości żelaza Fe w oleju silnikowym samochodów STAR 1142 z silnikiem 359M. Badania prowadzono na pięciu samochodach w zakresie przebiegu drogowego od O do 100 tyś .km. Uzyskane wartości porównano z wynikami wcześniej prowadzonych badań stanowiskowych i drogowych na samochodach STAR 200 z silnikiem 359. Badania przeprowadzono w ramach projektu badawczego KBN nr PB 144/T12/97/13.

EN

The tests of iron content in engine oil of trucks STAR 1142 with engines 359M are presented in the paper. The tests were carried out on the sample of five trucks used under the supervision during the mileage from O to 100 000 km. Obtained results were compared with results of earlier executed stand and route tests carried out on the sample of trucks STAR 200 with engines 359.

3

Studies on the Configuration and Structural Stability for Subnitrosyl Fe(NO)n (n = 1–4)

71%

Wang W. , Zhou Z. , Ma H. , Zhao S. , Chen J.

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2007

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tom Vol. 81, nr 4

573-589

EN

The structural properties and vibrationalmode of the transitionmetal Fe subnitrosyl complexes Fe(NO)n (n = 1–4) have been examined by using HF, B3LYP, B3P86 and B3PW91 methods at 6-311G basis set level. Results indicate that the interaction between Fe and NO should be characterized as a dative bond, in whichmonosynapic basin of the nitrogen plays the role of the disynapic basin connecting the metal core to the nitrogen atom. It shows that Fe(NO)n (n = 1–4) species have two states. Interestingly, for FeNO and Fe(NO)3 molecules, they are doublet (2 ) and quartet (4 ) states, while for Fe(NO)2 and Fe(NO)4 molecules, they are triplet ( 3 ) and quintet (5 ) states. The ground state of FeNO is of doublet (2 ) symmetry, but we have found that the two states of FeNO are very close in energy at different computational levels, and they are both belonging to Cv point group. For Fe(NO)2 species, the two states (3 and 5 ) have v-type structures (C2v point group) and linear structures (Dh point group). The same as FeNO species, the two states have similar energies. According to the analysis of the bond lengths, the ground state is the quintet (5 ) statewith a linear structure. In Fe(NO)3 species, the doublet(2 ) state and quartet (4 ) state are also close in energies, and they both have planar structures. The difference is that the doublet (2 ) state has a equilateral triangle structure, belonging to D3h point group, while the quartet (4 ) state has a isoceles triangle structure. The Fe(NO)4 species have a cube (Td point group) structure in the triplet (3 ) state and a similar cube structure in thequintet ( 5 ) state.Detailed bonding analysis has implied that the existence of the polynitrosyl Fe with more NOs and of other similar transition metal nitrosyl complexes is possible.

4

Recovering technology of Fe and Zn from EAF electrofilter dust

67%

Iorga G. , Demi P. , Stan S. , Predescu C.

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2008

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tom Vol. 53, iss. 2

619-624

EN

The steel production in Romania generates every year about 230,000 tons of wastes as powders and sludge containing 25-60% Fe but also important quantities of other metals like Zn (<15%) and Pb (<2%). They are also produced approximately 32% dusts (BF + EAF) and 68% sludge (BF and BOF). From this whole quantity, about 90,000 t/year is recovered and recycled inside the integrated flow, the balance being stored. As dusty wastes unrecicled in romanian steel industry until now we can note: BOF fine sludge, blast furnace sludge and EAF dust. The present work is developed in the framework of a research program financed by the Romanian Government, regarding „The ecology of metal cycle”, focussed especialy on the EAF dust. The paper presents the results of pilot experiments performed at the Metallurgical Research Institute in Bucharest aiming at the: – recovery of Fe from EAF dust under the form of metallized self reducing pellets (min. 40% Fe), complying with their application in EAF; – separation and recovery of Zn in the form of ZnO of high purity (> 99%), as required by its application in the nonferrous/chemical industry.

PL

Przemysł stalowniczy w Rumuni wytwarza corocznie około 230 000 ton odpadów w postaci pyłów i szlamów zawierających około 25-60% Fe oraz równie duże ilości innych metali, takich jak Zn (<15%) i Pb (<2%). W tym produkowane jest około 32% pyłów (wielki piec + piec łukowy) oraz 68% szlamów (wielki piec + konwertor tlenowy). Z całej ilości odpadów około 90 000 ton rocznie poddaje się utylizacji w zamkniętym obiegu wewnętrznym, reszta jest składowana. Nie są poddawane recyklingowi w rumuńskim przemyśle stalowym do dzisiaj szlamy z konwertora tlenowego i wielkiego pieca oraz pyły z pieca łukowego. Obecnie trwają prace finansowane przez rumuński rząd, mające na celu wprowadzenie w życie programu „The ecology of metal cycle”, którego głównym aspektem jest utylizacja pyłów powstających podczas procesu EAF. W artykule przedstawiono wyniki pilotowych eksperymentów przeprowadzonych w Metallurgical Research Institute w Bu- kareszcie mających na celu: – odzysk Fe z pyłów z EAF w postaci samo redukujących się brykietów (min. 40% Fe), wykorzystywanych później jako wsad do pieców w procesie EAF, – separacja i odzysk Zn w postaci ZnO o wysokiej czystości (> 99%), jaka jest wymagana przy zastosowaniu w przemyśle materiałów nieżelaznych lub chemicznym.

5

Content of microelements in the selected organ s of raccoon dog (Nyctereutes procyonoides)

67%

Mertin D. , Szeleszczuk O. , Süvegova K. , Niedbala P. , Hanusova E.

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2006

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tom Vol. 13, nr 1-2

85-90

EN

The concentration of microelements Fe, Co, Zn, Mn in selected organs of rac-coon dog (Nyclerellfes procyonoides) was determined. The elements were de-tected by the method of atomic absorption spectral photometry. When evaluating the differences between sexes in concentration of studied microelements we found significant differences only in the concentration of copper in brain, heart and muscle, zinc in kidneys and liver. We found the highest concentration of iron, in spleen and liver of males and females. Iron had the highest concentration out of all studied elements also in the rest of organs except for bones, in which was the highest concentration of zinc (190.63 mg/kg in males, 147.63 mg/kg in females). We noticed the greatest difference between sexes in concentration or manganese in bones, małe: 2.56 mg/kg dry matter, female 1.36 mg/kg dry matter.

PL

Określono zawartość mikroelemntów, Fe, Cu, Zn i Mn w wybranych narządach jenotów hodowlanych za pomocą metody absorpcyjnej spektrofotometrii atomowej. Znaczące statystycznie różnice pomiędzy samcami a samicami stwierdzono jedynie w koncentracji Cu w mózgu, sercu i mięśniach oraz Zn w nerkach i wątrobie. W wątrobie i śledzionie osobników obu grup stwierdzono wyjątkowo dużą zawartość Fe. Wśród analizowanych mikroelementów pierwiastek ten wykazywał największą koncentrację we wszystkich narządach, z wyjątkiem kości, gdzie dominował cynk. W kościach zanotowano również największe różnice w koncentracji Mg w kościach: u samców 2,58 mg/kg sm. u samic 1,35 mg/kg s.m.

6

Influence of various ash-sludge and ash-peat mixtures on quantity and quality of maize yield. Part 2. Microelements

59%

Antonkiewicz J.

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2007

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tom Vol. 14, nr 3-4

257-263

EN

The research aimed to identify the influence of different quantities of ash-sludge and ash-peat mixtures addition to the soil on microelement contents in maize. The studies were conducted in 2003-2005 as a pot experiment on mineral soil to which sludge-ash and peat-ash mixtures were supplemented in the quantity of 1-30% of the total mass of substratum. The experimental design considered also the objects comprising only individual components of the mixtures. It was found Chat under the influence of the increasing percentage of ash-sludge and ash-peat mixtures in soil the content of Fe, Al and Si in maize was systematically growing, whereas Mn and Co contents were diminished. Iron content in maize aboveground parts was on the optimal level, whereas manganese content was over the norm and cobalt deficiency was registered.

PL

Badania miały na celu poznanie wpływu różnych ilości mieszanin popiołowo-osadowych i popiołowo-torfowych dodanych do podłoża na zawartość mikroelementów w kukurydzy. Badania przeprowadzono w latach 2003-2005 w warunkach doświadczenia wazonowego na glebie mineralnej, do której dodawano mieszaniny osadowo-popiołowe i torfowo-popiołowe w ilości 1-30% w stosunku do ogólnej masy utworu glebowego. W schemacie doświadczenia uwzględniono też obiekty obejmujące jedynie komponenty wchodzące w skład mieszanin. Stwierdzono, że pod wpływem wzrastającego udziału mieszanin popiołowo-osadowych i popiołowo-torfowych w podłożu systematycznie wzrasta zawartość Fe, Al i Si w kukurydzy, natomiast maleje zawartość Mn i Co. Zawartość żelaza w częściach nadziemnych kukurydzy kształtowała się na poziomie optymalnym w paszach dobrej jakości, natomiast zawartość manganu była nadmierna, a kobaltu niedostateczna.

7

Content and distribution of selected elements in the linseed (Linum usitatissimum L.) aboveground parts depending on the growth stage

51%

Antonkiewicz J. , Zając T.

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2007

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tom Vol. 14, nr 3-4

275-282

EN

The research aimed to analyse the contents of selected elements in linseed aboveground parts depending on the growth stage and the plant part, and assessment of linseeds fodder value. The aboveground parts yield, depending on the year of the experiment ranged between 0.235 and 6.81 Mg - ha-1. The content of analysed elements in linseed was greatly diversified and fluctuated from 0.06 to 8.60 mg Cr; 6.45105.0 mg Zn; 0.01-1.47 mg Pb; 0.96-9.88 mg Cu; 0.29-8.10 mg Cd; 0.54-12.4 mg Ni; 13.70-544.64 mg Fe; 0.02-0.60 mg Co and 3.65-137.0 mg Mn kg-1 d.m. Among the analysed elements cadmium content were the most diversified, whereas copper the least. It was found that linseed leaves accumulated much more microelements than stems. Chromium and manganese content in linseed did not exceed the standards for good quality fodder. Heavy metal content in linseed aboveground parts did not exceed limit values considered as admissible content of these elements in fodder. Only Cd limit fodder content were exceeded at all growth stages.

PL

Celem badań była analiza zawartości wybranych pierwiastków w częściach nadziemnych lnu oleistego w zależności od stadium rozwojowego i części rośliny oraz ocena wartości paszowej nasion lnu. Plon części nadziemnych lnu oleistego, w zależności od roku prowadzenia doświadczenia, wahał się od 0,235 do 6,81 Mg - ha-1. Zawartość badanych pierwiastków w Inie oleistym była bardzo zróżnicowana i wahała się w zakresie: 0,06-8,60 mg Cr, 6,45-105,0 mg Zn; 0,01-1,47 mg Pb; 0,96-9,88 mg Cu; 0,29-8,10 mg Cd; 0,54-12,4 mg Ni; 13,70-544,64 mg Fe; 0,02-0,60 mg Co i 3,65-137,0 mg Mn o kg -1 s.m. Spośród analizowanych pierwiastków największe zróżnicowanie zawartości stwierdzono w przypadku kadmu, a najmniejsze dla miedzi. Stwierdzono, że liście lnu oleistego gromadziły znacznie więcej mikroelementów aniżeli łodygi. Zawartość chromu i manganu w Inie oleistym nie przekraczała norm dla pasz dobrej jakości. Zawartości metali ciężkich w częściach nadziemnych lnu oleistego nie przekroczyły wartości granicznych uznawanych za dopuszczalne koncentracje tych pierwiastków w paszach. Jedynie w przypadku Cd we wszystkich stadiach rozwojowych lnu stwierdzono przekroczenie granicznej zawartości tego pierwiastka w paszach.

8

Heavy metal toxicity - metabolism, absorption, distribution, excretion and mechanism of toxicity for each of the metals

48%

Magelsir H. M. I.

World News of Natural Sciences

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2016

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tom 4

20-32

EN

The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the WHO. Heavy metals have been used by humans for thousands of years. Although several adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues, and is even increasing in some parts of the world, in particular, in less developed countries. However, over the last 100 years, emissions have declined in most developed countries. Cadmium compounds, the exception, are currently mainly used in re-chargeable nickel-cadmium batteries. Cadmium emissions have increased dramatically during the 20th century, one reason being that cadmium-containing products are rarely re-cycled, but often dumped together with household waste. Cigarette smoking is a major source of cadmium exposure. In non-smokers, food is the most important source of cadmium exposure. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously anticipated, primarily in the form of kidney damage, but possibly also in bone effects and fractures. Many individuals in Europe already exceed the recommended exposure levels and the margin is very narrow for large groups. Therefore, measures should be taken to reduce cadmium exposure in the general population in order to minimize the risk of adverse health effects. The general population is primarily exposed to mercury via food, fish being a major source of methyl mercury exposure, as is dental amalgam. The general population, however, does not face a significant health risk from methyl mercury, although certain groups with high fish consumption may attain blood levels associated with a low risk of neurological damage to adults. Since there is a risk to the fetus in particular, pregnant women should avoid a high intake of certain fish, such as shark, swordfish and tuna; fish (such as pike, walleye and bass) taken from polluted fresh waters should especially be avoided. There has been a debate on the safety of dental amalgams and claims have been made that mercury from amalgam may cause a variety of diseases. However, there are no studies so far that have been able to show any associations between amalgam fillings and ill health. The general population is exposed to lead from air and food in roughly equal proportions. During the last century, lead emissions to ambient air caused considerable pollution, mainly due to lead emissions from petrol. Children are particularly susceptible to lead exposure due to high gastrointestinal uptake and the permeable blood-brain barrier. Blood levels in children should be reduced below the levels so far considered acceptable as recent data indicates that lead may hold neurotoxic effects at lower levels of exposure than previously anticipated. Although lead in petrol has dramatically decreased over the last decades, thereby reducing environmental exposure, phasing out any remaining uses of lead additives in motor fuels should be encouraged. The use of lead-based paints should also be abandoned, and lead should not be used in food containers. In particular, the public should be aware of glazed food containers, which may leach lead into food. Exposure to arsenic is mainly via intake of food and drinking water, food being the most important source in most populations. Long-term exposure to arsenic in drinking water is mainly related to increased risks of skin cancer, but also enhanced risk of some other cancers, as well as other skin lesions such as hyperkeratosis and pigmentation changes. Occupational exposure to arsenic, primarily by inhalation, is causally associated with lung cancer. Clear exposure-response relationships and high risks have been observed.