Novi metod određivanja specifične površine elektrohemijski istaloženog bakra

The specific surface of electrodeposited copper was determined using recently proposed way for the estimation of the real surface area of metal deposits. The obtained values of the specific surface of copper deposits were correlated with the corresponding morphologies of copper deposits.Specifična površina elektrohemijski istaloženog taloga bakra je bila određena korišćenjem nedavno predloženim načinom za procenu realne površine taloga metala. Dobijene vrednosti specifične površine taloga bakra su bile povezane sa odgovarajućim morfologijama taloga bakra

Uticaj strukture čestica na nasipnu masu elektrolitički dobijenog bakarnog praha

The quantitative microstructural analysis and the sieve analysis of copper powder as well as the scanning electron microscopy analysis of the copper powders particles were performed. It was found that the structure of the copper powder particles determines the apparent density of copper powder. The powder particles from the same fractions of different powders occupy approximately the same volume, but the structure of metallic copper is very different. This causes the difference in apparent densities of copper powder obtained under different conditions. The more dendritic is the structure of powder particles the smaller is the apparent density of copper powder.Izvršena je kvalitativna mikrostrukturna i granulometrijska analiza bakarnih prahova kao i analiza morfologije i strukture čestica praha pomoću skenirajuće elektronske mikroskopije (SEM). Ustanovljeno je da struktura čestica praha određuje nasipnu masu bakarnog praha. Čestice iste frakcije različitih prahova zauzimaju otprilike istu zapreminu, ali je struktura metalnog bakra različita. Ovo uzrokuje razlike u nasipnoj masi bakarnog praha dobijenog pod različitim uslovima. Što je struktura čestica više dendritična to je manja nasipna masa bakarnog praha

The Assessment of the Analytic Group Treatment Efficiency According to Yalom’s Classification

The authors expose the assessment of therapeutic factors during group analytic treatment. In the methodology of research several measuring instruments were applied. In this study it will be exposed the results obtain by Yalom\u27s questionnaire containing 60 items. Three small analytic groups were followed up, encompassing 20 group members. By self-evaluation they ranked the assessment of every of 12 therapeutic factors according to their importance. The variability of results was shown more inside then among groups. The highest-ranking therapeutic factors the group members sorted out were: self-understanding, family re-enactment, cohesiveness and universality. The factor of identification was the lowest ranking in all group

An inviscid dyadic model of turbulence: the fixed point and Onsager's conjecture

Properties of an infinite system of nonlinearly coupled ordinary differential equations are discussed. This system models some properties present in the equations of motion for an inviscid fluid such as the skew symmetry and the 3-dimensional scaling of the quadratic nonlinearity. It is proved that the system with forcing has a unique equilibrium and that every solution blows up in finite time in $H^{5/6}$-norm. Onsager's conjecture is confirmed for the model system

Uticaj reversne struje na nasipnu masu pri elektrolitičkom taloženju bakarnog praha

The possibility of depositing copper powders with different apparent density by changing the shape of reversing current wave is shown. The morphology and crystallinity of powder particles can be varied considerably by changing shape of the reversing current wave and, hence, the apparent density of powders. The relation of apparent density with particle morphology and structure was illustrated.U radu je pokazana mogućnost dobijanja bakarnih prahova različitih nasipnih masa promenom oblika talasa reversne struje. Uspostavljena je zadovoljavajuća veza između morfologije i strukture čestica praha bakra i nasipne mase praha

Histamin u ribi dostupnoj na tržištu Srbije u 2018. godini

Histamine is a biogen amin, which is formed by decarboxylation of the histidine amino acid, under the action of the L-histidine-decarboxylase enzyme. High level of free histidine in fish meat, bacterial histidin decarboxylase activity and high temperature of storage elevate the level of histamine. Among the most important factors that can affect the level of histamine in fish meat are the type of fish and the method of its preservation. In order to determine this dependence, 1030 samples of frozen fish (tuna, mackerel, sardines and sprat) and 167 samples of canned fish (tuna, sardines and mackerel) were monitored for histamine content by ELISA method. It was determined a lower concentration of histamine in frozen fish (from 5.71 mg/kg to 18.03 mg/kg) compared to canned fish (from 15.03 mg/kg to 110.6 mg/kg). The highest histamine concentrations were found in the mackerel samples, regardless of the preservation method (110.6 mg/kg in canned mackerel and 18.03 mg/kg in frozen mackerel), which were significantly higher compared to the histamine levels found in cans of tuna and sardines (p ˂0.0001). Of the total number of samples, three samples (two samples of canned sardines and one sample of canned mackerel) were declared unsafe for human health. In most of the analyzed samples, the level of determined histamine was relatively low, which confirms adequate implementation of control protocols and efficant surveillance of products placed on the Serbian market.Histamin je bioaktivni amin, koji nastaje u reakciji dekarboksilacije aminokiseline histidina, pod dejstvom enzima Lhistidin dekarboksilaze. Visok nivo slobodnog histidina u mesu ribe, aktivnost enzim produkujućih bakterija i visoke temperature skladištenja deluju predisponirajuće na sintezu histamina. Među najznačajnije faktore koji utiču na koncentraciju histamina u mesu ribe jesu vrsta ribe i metod njenog konzervisanja. U cilju utvrđivanja ove zavisnosti, uzorci zamrznute ribe (tune, skuše, sardine i papaline) i ribe u konzervi (tune, sardine i skuše) su analizirani ELISA metodom. Utvrđene su niže koncentracije histamina u uzorcima zamrznute ribe (od 5.71 mg/kg do 18.03 mg/kg) u poređenju sa konzervama od ribe (od 15.03 mg/kg do 110.6 mg/kg). Najviše koncentracije histamina su ustanovljene u uzorcima skuše, bez obzira na metod konzervisanja (110.6 mg/kg u konzervama od skuše i 18.03 mg/kg u zamrznutoj skuši), koje su bile i statistički značajno veće u odnosu na konzerve tune i konzerve sardine (p ˂0.0001). Od ukupnog broja uzoraka, samo tri uzorka (dva uzorka sardine u konzervi i jedan uzorak skuše u konzervi) su proglašeni nebezbednim za zdravlje ljudi. U najvećem broju ispitanih uzoraka izmerene su relativno niske koncentracije histamina, što ukazuje na adekvatno sprovođenje kontrole i nadzora nad proizvodima koji se plasiraju u promet na srpskom tržištu

Uticaj oblika i strukture čestica na tečljivost elektrolitičkog bakarnog praha II - eksperimentalna potvrda modela reprezentativne čestice praha

An analysis of the effects of the shape, surface structure and size distribution of particles on the flow ability of the copper powder was performed. It is shown that the most important property of the particles of a powder, regarding the flow ability of the powder, is the surface structure of the particles.Izvedena je analiza uticaja oblika, površinske strukture i raspodele veličina čestica na tečljivost bakarnog praha. Pokazano je da površinska struktura predstavlja najvažnije svojstvo čestice praha u odnosu na njegovu tečljivost

Inflammation of Ectopic Pancreatic Tissue as Unusual Cause of Duodenal Perforation – A Case Report

Ectopic pancreatic tissue, also known as a pancreatic rest, is an uncommon congenital anomaly defined as extrapancreatic tissue located far from the pancreas and without any connection via vascular or anatomical means to it. Such tissue may occur throughout the GI tract but has a propensity to affect the stomach and the proximal small intestine. The majority of patients with pancreatic ectopia are asymptomatic, but when symptoms occur, they can be presented in a variety of ways. We report a patient with acute surgical abdomen due to a duodenal perforation caused by inflammation of ectopic pancreatic tissue in duodenum and stomach. Histology of the resected duodenum and stomach demonstrated heterotopic pancreatic tissue acute inflammation without atypia, suggesting »pancreatitis of the duodenum and stomach«. To date, there have been a few reports describing perforation of the stomach due to heterotopic pancreas. Therefore, the present case was considered to be a very rare case of this disorder. To conclude, heterotopic pancreas should always be considered in the differential diagnosis of acute abdomen

a-Hydrogen Exchange in the Re action of 2-Phenylethyldimethylsulphonium Ion with Base in Aqueous Solution and of 2-Phenylethyltrimethylammoni um Ion with Base in Aqueous and Alcoholic Solution

a-Hydrogen exch ange during the elimination from 2-phenylethyldimethylsulphonium bromide with on- in d euterium oxide h as been found to b e a lmost complete under certain r eactio n conditions. The product, trimethylamine, from the a n a logo u s reaction of 2-phenylethyltrimethylammonium iodide with eith er ethoxide ion in ethanol-0-d or with OD- in d~u terium oxide was found to contain no d etectabl e amount of deuterium above natural abundance