Intensification of zinc dissolution process in sulphuric acid

Many high purity salts are produced by dissolving pure metal in non-oxidizing mineral acids. If hydrogen overpotential on the given metal is high, then the rate of overall process is defined by reaction of hydrogen ion reduction. This study investigated the possibility of accelerated dissolving of metal zinc in sulphuric acid by introducing copper cathode on which evolving hydrogen is much easier than on zinc. It was found out that the acceleration of zinc dissolving is possible and, at constant surface of copper cathode depends on the quality of electrical contact between copper electrode and zinc

Study of corrosion resistance of chromium-nickel steel in calcium - hypochlorite solution. Part 1. Steels uranus b6

Corrosion resistance of Cr - Ni (special steels) specimen is tested by electrochemical methods, numerical method of linear polarization and polarization resistance method in calcium-hypochlorite (Ca(OCl)2) solutions. With increasing of Ca(OCl)2 concentration, pH value of the solution increases, as well as active chlorine concentration and corrosion activity of the medium. According to the quantitative method of the corrosion resistance determination it can be concluded that the steels tested in 1 wt % Ca(OCl)2 solution are resistant, in 10 wt % solution constant, and in 50 wt % suspension less resistant. URANUS B6 showed the best corrosion resistance of all tested chromium - nickel steels in all tested corrosion mediums

Uticaj aditiva na brzinu korozije limenke napunjene komadima kajsije

Polarization techniques are used for testing the impact of different compounds (additives) on tinplate corrosion, using pieces of apricot dipped in syrup with and without nitrate addition as electrolyte solution, at the same time using filled cans as electrolytic cell and operating electrode. This procedure determined the intensity of inhibiting tin dissolving with some of the used additives like sodium-benzoate, potassium-sorbate sodium-lauril-sulphate and p-aminobenzoate acid. Adding these additives to canned pieces of apricot in syrup led to inhibiting of tin dissolving, which was experimentally proved.Primenom polarizacionih tehnika ispitivan je uticaj različitih supstanci (aditiva) na koroziju belog lima od kojeg su napravljene limenke primenjujući kao rastvor elektrolita komade kajsije u sirupu sa i bez dodatka nitrata, uz istovremeno korišćenje napunjene konzerve kao elektrolitičke ćelije i kao radne elektrode. Ovim postupkom je određena jačina inhibiranja rastvaranja kalaja nekim od primenjenih aditiva, kao što su: natrijum-benzoat, kalijum-sorbat, natrijum-lauril-sulfat i p-amino-benzoeva kiselina. Dodatkom ovih aditiva u konzervisane komade kajsije u sirupu došlo je do inhibiranja rastvaranja kalaja što je eksperimentalnim putem i dokazano

A NEW PROCEDURE FOR OBTAINING CALCIUM SULPHATE α-HEMIHYDRATE ON THE BASIS OF WASTE PHOSPHOGYPSUM

Investigations, conducted in this study showed that waste phosphogypsum-dihydrate represents a burden which even must not be kept in deposits because of its large quantity in relation to the main product – phosphoric acid, as well as because of great impact of a phosphogypsum deposit on the environment. By the proposed procedure, calcium-sulphate dehydrate is transformed into a far purer α-hemihydrate which, with its physic-chemical characteristics, approaches natural gypsum and contains additional components which enable formation of small-grain phosphogypsum which may be utilised in construction industry. Test installation, given in this study, is highly automated and designed in such way to be operated by only one person. The obtained α-hemihydrate may be utilised for obtaining of gypsum blocks and dry hemihydrat

Modeling the mechanism of ethanol effect on nonlinear dynamical states of the hypothalamic-pituitary-adrenal system.

Predmet istraživanja ove doktorske disertacije je ispitivanje uticaja etanola na dinamička stanja biohemijskih procesa koji čine hipotalamo-hipofizno-adrenalnu osu (HPA, od eng. hypothalamic-pituitary-adrenal). HPA osa objedinjuje hipotalamus, hipofizu i koru nadbubrežnih žlezda u jednu celinu...The research topic of this doctoral thesis is to examine the influence of ethanol on the dynamical states of biochemical processes underlying the hypothalamic-pituitary-adrenal (HPA) axis. HPA axis incorporates the hypothalamus, pituitary and adrenal glands into one entity..

Low-dose ionizing irradiation affects ntpdase activity in neuoronal cells of young female rats

In the present study, time-dependent effects of low-dose ionizing irradiation on membrane-bound enzyme activity in neuronal cell endings of young female rat brains were sudied. The ecto-adenosine triphospho diphosphohydrolases (NTPDases) hydrolyse the extracellular nucleotide di- and tri- phosphates (ADP and ATP) in the presence of divalent cations (Ca2+ and Mg2+). The influence of whole-body irradiation on membrane enzymes ATP and ADP hydrolysing activity were monitored 1, 24 and 72 h after irradiation. Animals were divided into three groups: non-treated, under physiological conditions (C), immobilized and whole body irradiated with 50 cGy by γ-rays (R) and immobilized non-irradiated (I) animals. It was shown that the levels of ATP and ADP hydrolyses were not affected within 72h after immobilisation. Lowdose irradiation significantly decreased hydrolyses of extracellular ATP as early as 1h after irradiation. ADP hydrolyses within 72 h and ATP hydrolysis after 24 h were not altered.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Investigating prevalence of beta-2 adrenergic receptors polymorphisms and correlation with therapeutic response in patients with bronchial asthma

Polimorfizmi gena za receptor beta2-adrenergičkih (ADRB2) su klinički relevantni iz nekoliko razloga, uključujući i kao faktor rizika za nastanak astme, stepen njene težine, kao i modulacije efikasnosti terapije beta2-agonista. Cilj ovog istraživanja bio je da se ispita povezanost između ADRB2 polimorfizama gena i astme u srpskoj populaciji, te da se proceni terapijski odgovor u odnosu na ADRB2 genotip. U istraživanju je učestvovalo 171 bolesnika s astmom i 101 zdravih osoba kao kontrolna grupa. Genotipizacija Arg16Gly i Gln27Glu polimorfizama je izvedena direktnim sekvenciranjem prozvoda lančane reakcije polimeraze (PCR). U srpskoj odrasloj populaciji, nosioci 27Gln alela i 27Gln / Gln genotipa su pokazali veći rizik od nastanka astme [(OR) 2.5, 95% interval poverenja (CI) 1,6- 3,8, a OR 3.00, 95% CI 1,7-5,3, odnosno], dok je nađeno da prisustvo 27Glu alela i 27Gln / Glu genotip imaju zaštitni efekat (OR 0.4; 95% CI 0,3-0,6, ili OR, 0.3, 95% CI 0.1-0.7, respektivno). Nadalje, utvrdili smo da prisustvo 27Gln alela u astmatičara mlađih od 50 godina dovodi do boljeg odgovora na terapiju s dugodelujućim beta2-agonistima (LABA) u kombinaciji sa niskim i umerenim dozama inhalacijskih kortikosteroida (ICS), za razliku od starijih gde nosioci 27Glu alela stariji od 50 godina imaju veću verovatnoću da će bolje odgovoriti na LABA + ICS terapiju. U zaključku, identifikovali smo da su u srpskoj odrasloj populaciji 27Gln alel i homozigotna kombinacija 27Gln faktori rizika za nastanak astme, što može biti od kliničkog interesa u prevenciji bolesti...Polymorphisms of beta2-adrenergic receptor gene (ADRB2) are clinically relevant for several reasons, including as a risk factor for asthma development/severity and prediction for the effectiveness of treatment with beta2-agonists in reducing asthma symptoms. The aim of this study was to examine the association between ADRB2 gene polymorphisms and asthma in Serbian population, and to evaluate the therapeutic response in relation to the ADRB2 genotype. The study included 171 patients with asthma and 101 healthy subjects as the control group. Genotyping of Arg16Gly and Gln27Glu polymorphisms was performed by direct sequencing of polymerase chain reaction (PCR) products. In Serbian adults, carriers of the 27Gln allele and 27Gln/Gln genotype were at higher risk of asthma [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.6-3.8, and OR 3.00, 95% CI 1.7-5.3, respectively], while the presence of the 27Glu allele and 27Gln/Glu genotype were found to be protective of asthma (OR 0.4, 95% CI 0.3-0.6, and OR 0.3, 95% CI 0.1-0.7, respectively). Furthermore, we found that the presence of the 27Gln allele in asthmatics younger than 50 years leads to a better response to therapy with long-acting beta2-agonists (LABA) in combination with prevailing low and moderate doses of inhaled corticosteroids (ICS), while carriers of the 27Glu allele over 50 years old are more likely to respond to LABA + ICS therapy. We identified that in Serbian adults the 27Gln allele and 27Gln homozygosity are risk factors for asthma, which may be of clinical interest in disease prevention..

THE DETERMINATIONS OF TOTAL ACIDS IN RED WINE

The amount of total acids in must is in most number of cases between 5 and 8 g/dm3 . Wines in general possess a little fewer acids than must, by Regulation the least acidity, expressed as tartaric acid is for all kinds of wine 4.5 g/dm3 , because a part of tartaric acids sediments as salt (tartar) in the process of the alcohol fermentation. For wines that possess less than 4 g/dm3 of total acids there is a doubt are they of natural background. Because of that the aim of this work was determination of total acids in diferent sorts of red wines and to determinate their background using gained data. For determinating total acids in white wine neutralization method was used. As potentiometric titration for pH 7.00 is precise and accurate method and values of content of total acids in wine, exppressed by tartaric acid, are given by these results. The analisys of differential potentiometric curves indicates that these curves can give the answer to the questions: are there inorganic supstances, amino groups and phenols present in analised samples

Automatic Synonym Discovery with Knowledge Bases

Recognizing entity synonyms from text has become a crucial task in many entity-leveraging applications. However, discovering entity synonyms from domain-specific text corpora (e.g., news articles, scientific papers) is rather challenging. Current systems take an entity name string as input to find out other names that are synonymous, ignoring the fact that often times a name string can refer to multiple entities (e.g., "apple" could refer to both Apple Inc and the fruit apple). Moreover, most existing methods require training data manually created by domain experts to construct supervised-learning systems. In this paper, we study the problem of automatic synonym discovery with knowledge bases, that is, identifying synonyms for knowledge base entities in a given domain-specific corpus. The manually-curated synonyms for each entity stored in a knowledge base not only form a set of name strings to disambiguate the meaning for each other, but also can serve as "distant" supervision to help determine important features for the task. We propose a novel framework, called DPE, to integrate two kinds of mutually-complementing signals for synonym discovery, i.e., distributional features based on corpus-level statistics and textual patterns based on local contexts. In particular, DPE jointly optimizes the two kinds of signals in conjunction with distant supervision, so that they can mutually enhance each other in the training stage. At the inference stage, both signals will be utilized to discover synonyms for the given entities. Experimental results prove the effectiveness of the proposed framework

Uticaj nivoa mlečnosti na osobine plodnosti krava crno bele rase

In this study a relationship between the milk yield and following reproduction traits: number of inseminations per conception [AIS], service period [SP], age at calving [AC], calving interval [CI] and birth weight [BW] is studied. The research involved dairy cows of European type of Black and White cattle which are being intensively improved by the genes of Holstein - Friesian breed. Mean values of general average for number of inseminations per conception, service period, age at calving, calving interval and birth weight are: 2.00; 98.78; 1088.08; 376.70 and 36.40, respectively. In general, the estimated phenotypic correlations (rp) between the milk yield over standard lactations and fertility traits were positive and unfavorable, and ranged from 0.24 for the relationship between milk yield and birth weight to 0.70 for relationship between milk yield and age at calving.U radu je ispitivan odnos između prinosa mleka i sledećih osobina plodnosti: indeks osemenjavanja [IO], servis period [SP], uzrast pri teljenju [UT], međutelidbeni interval [MI] i masa teladi pri rođenju [MTR]. Ispitivanja su se odnosila na mlečne krave evropskog tipa crno-belih goveda koje se intenzivno oplemenjuju genima holštajn-frizijske rase. Za analizu je korišćen Metod najmanjih kvadrata - LSMLMW (HARVEY, 1990), fiksni model. Srednje vrednosti opšteg proseka za indeks osemenjavanja, servis period, uzrast pri teljenju, međutelidbeni interval i masu teladi pri rođenju su: 2,00; 98,78; 1088,08 ; 376,70 i 36,40, respektivno. Procenjene fenotipske korelacije (rp) između prinosa mleka i osobina plodnosti generalno su bile pozitivne i nepovoljne, i imale su vrednosti od 0,24 za odnos između prinosa mleka i masu teladi pri rođenju do 0,70 za odnos između prinosa mleka i uzrasta pri teljenju