Copper Electrodeposition onto Palladium from a Deep Eutectic System Based on Choline Chloride

Recently, there has been an increasing interest in developing nonaqueous electrolytes which have been widely employed as an alternative media for a range of metals and metal alloys electrodepositions. A promising and new class of electrolytes among ionic liquids (Ils) are deep eutectic solvents (DESs)1 . The purpose of the copper deposition study from DESs is the application of copper coating and copper alloys in both, industry and fundamental research. In this work, the electrochemical deposition of copper onto palladium working substrate from ChCl/EG (1:2 ratio) DES electrolyte at 50°C was investigated. Additionally, the Cu(II) electroreduction process was studied by potentiodynamic measurements, cyclic voltammetry, chronoamperometry, in the electrolytes with different concentrations of Cu(II) ions ranging from 0.1 M to 0.5 M. The cyclic voltammetry results indicated that the bulk deposition of Cu(II) begins to occur at around –0.080 V vs. Cu. It was found that copper deposition onto the Pd cathode from ChCl:EG electrolyte under potentiostatic conditions is achievable. Data collected from X-ray diffraction (XRD) analysis proved that the cathodic deposits are composed of Cu and CuPd intermetallic. CuPd alloys with different Pd-Cu ratios were prepared by constant potential of –0.100 V vs. Cu from ChCl/EG containing 0.1 M and 0.5 M Cu(II). It is worth noting that the Xray data indicated that the composition of the produced Pd-Cu films could be varied by changing the concentration of Cu(II) ions in the electrolyte or changing the deposition mode

Characteristics of traditional production of cheese in monestry rakovica

Као једна од најстаријих намирница, сир, због своје хранљиве вредности, заузима важно место у исхрани људи. Производња сира датира из далеке прошлости и имала је значаја у свим цивилизацијама. Сиреви се традиционално производе у Србији вековима, представљају културно наслеђе и акумулирано искуствено знање, које се преноси са генерације на генерацију. Историјски гледано, у средњем веку главна места где се одвијала производња сирева били су манастири и феудални поседи, тако да многе групе данашњих сирева потичу из тог времена. У Републици Србији, поред доминантне индустријске производње, сиреви се производе у занатским погонима, индивидуалним домаћинствима, али се традиционална производња задржала у малим заједницама као што су манастири. Циљ овог рада био је да се опише производња сира у манастиру Раковица, који се налази на територији Београда, Република Србија. Сиреви су испитани на присуство L. monocytogenes, коагулаза позитивних стафилокока, одређиван је број бактерија млечне киселине, ентеробактерија, као и физичкохемијски параметри (сува материја, маст, маст у сувој материји, вода, вода у безмасној материји, киселост, pH вредност, садржај NaCl, активност воде). Снимање технологије изведено је помоћу анкете састављене од питања, која обједињују основне елементе и технолошке поступке производње сира. Доминантну микрофлору су чиниле бактерије млечне киселине. Средња вредност броја Lactococcus spp. била је 6,34 log cfu/g и Lactobacillus spp. 5,49log cfu/g. У испитаним узорцима није доказано присуство L. monocytogenes и каогулаза позитивних стафилокока, док je средња вредноста броја Enterobacteriaceae била 4,05 cfu/g. Средња вредност за суву материју сира била је 40,19%, за маст у сувој материји сира 39,86%, за воду у безмасној материји 71,21 %, за укупне протеине 14,78%, за киселост 10,80°SH, pH вредност 6,20, за садржај NaCl 0,87% и актвност воде 0,953.As one of the oldest food products,cheese takes an important place in human diet due to its nutritional value. Cheese production dates back to the distant past and had importance in all civilizations. The cheeses are traditionally produced in Serbia for centuries and represent the cultural heritage and accumulated experiential knowledge, which is passed from generation to generation. Historically, in the Middle Ages the monasteries and feudal estates were the main places where the cheese production were carried out, so many groups of nowdays cheeses originate from this time. In the Republic of Serbia, additionaly to the dominant industrial productionat the industrial dairy plants, cheeses are produced in small scale plants and individual households, but traditional production had been kept in small communities such as monasteries. The aim of this study was to describe the production of cheese in the monastery "Rakovica", situated in Belgrade, Republic of Serbia. The cheeses were examined for the presence of L. monocytogenes, coagulase-positive staphylococci, the number of lactic acid bacteria, Enterobacteriaceae was determined and physicochemical parameters (total solids, fat, fat in total solids, moisture, moisture on a freefat basis, acidity, pH value, content of NaCl, water activity) as well. The observation of technology was carried out by the survey consisting of questions, which combines the basic elements and technological operations of cheese production. The lactic acid bacteria represented dominant microbita of cheese. The mean value for the number of Lactococcus spp. was 6.34 log CFU/g and Lactobacillus spp. 5,49 log cfu/g. L. monocytogenes and coagulase-positive staphylococci were not detected in the examined samples, whereas the mean value for the number of Enterobacteriaceae was 4.05 cfu/g. The mean value for total solids of cheese was 40.19%, for fat in total solids of cheese 39.86%, for moisture in free-fat basis 71.21%,for content of total proteins 14,78%, for acidity 10,80 °SH, for pH value of 6.20, for NaCl content 0.87% and water activity 0.953

METABOLIČKA AKTIVNOST TERMOREZISTENTNIH MIKROORGANIZAMA

Termorezistentni mikroorganizmi, zahvaljujući otpornosti na termičke tretmanekoji se primenjuju u industriji mleka, kao i mogućnostima rasta i metaboličkimaktivnostima u uslovima čuvanja gotovih proizvoda, imaju značaja kao mikro -organizmi kvara. Ova osobina deNiniše tehnološki značaj termorezistentnih mikro -organizama.Među populacijom termorezistentnih mikroorganizama, Bacillus spp. pokazujuznačajnu proteolitičku aktivnost, a s obzirom na njihovo svojstvo razlaganja kazeina,potencijal njihove proteolize može se uspešno koristiti u koagulaciji mleka i zrenjasireva. Veliki značaj imaju proteinaze Bacillussubtilis, čiji se proteolitički enzimiuspešno primenjuju u proizvodnji Chedar, Munster i Camembert sira. Suprotnoovome, aktivnost proteina za Bacillus spp. u sterilisanom mleku, u uslovima ne -adekvatnog čuvanja dovodi do slatkog grušanja ili pojave gorkog ukusa mleka, kaorezultat nastanka gorkih peptida, dok preterana aktivnost proteinaza bacila priproizvodnji Chedar sira uslovljava gruš mekše konzistencije, veći sadržaj proteina imasti u surutki, što dovodi do smanjenog randmana sira za 10%. Oslobađanjem nižihmasnih kiselina delovanjem lipolitičkih enzima poreklom od mikroorganizama,razvija se neprijatan ukus i miris, što predstavlja manu poznatu pod imenomhidrolitička užeglost. Od termorezistentnih mikroorganizama, sposobnost hidrolizemasti pokazuju mikroorganizmi roda Bacillus.Cilj ovog rada bio je da se ispita sposobnost termorezistentnih mikro organizamaizolovanih iz mleka da razlažu proteine, masti i skrob, što dovodi do kvara mleka iproizvoda od mleka.Od ukupno 80 izolata termorezistentnih mikroorganizama, proteolitičkuaktivnost je ispoljilo 35 (43,75%) izolata u uslovima inkubacije pri 30oC/72h i 30(37,50%) izolata u uslovima inkubacije pri 20±2oC/72h, dok nijedan izolat nijeispoljio proteolitičku aktivnost u uslovima inkubacije pri 10±1oC/10 dana.Amilolitička aktivnost je utvrđena kod 16 (20,0%) izolata u uslovima inkubacije pri30oC/72h i 15 (18,75%) izolata u uslovima inkubacije pri 20±2oC/72h. Amilolitičkaaktivnost termorezistentnih mikroorganizama izostaje u uslovima inkubacije pri10±1oC/10 dana. Ispitivani izolati termorezistentnih mikroorganizama nisu pokazalilipolitičku aktivnost, bez obzira na primenjene različite uslove inkubacije

Phytochemical analysis and antiradical potential of methanol extracts of Hieracium naegelianum Pančić and H. scheppigianum Freyn underground parts

The genus Hieracium L. is autochthonous in Eurasia, North Africa and North America and the vast majority of the taxa are distributed in Europe. Hieracium naegelianum Pančić, belonging to monotypic subendemic section H. sect. Naegeliana Zahn ex Szeląg, is a small, caespitose plant, with long rhizome. It inhabits subalpine and alpine orosubmediterranean screes and mainly is endemic for the mountains in W Balkan, with a single population in S Apennines. Hieracium scheppigianum Freyn is a hybridogenous apomictic species probably originated from H. gymnocephalum Griseb. ex Pant. (H. sect. Pannosa /Zahn (Zahn) and H. bupleuroides C.C. Gmelin, s. l. (H. sect. Drepanoidea Monnier). The species can be found only on screes, rocky places or rocky pastures in subalpine and alpine zone in Dinarides. The underground parts of H. naegelianum and H. scheppigianum were collected on Mt Durmitor, Republic of Montenegro. Dried and powered plant material was macerated with dichloromethane and methanol, successively. Both solvents were evaporated under reduced pressure and dried methanol extracts were used for further investigation. Using LC-MS method, sesquiterpene lactone glycoside of guaianolide type, crepiside E, and six phenolic acids, i.e. chlorogenic acid and five dicaffeoylquinic acids (cynarin, 3,5-, 1,5-, 3,4- and 4,5-dicaffeoylquinic acids) were identified and quantified in both dried methanol extracts. Crepiside E was the most abundant compound (116.58 and 126.88 mg/g), while among phenolic acids, 3,5-dicaffeoylquinic acid (72.86 and 62.01 mg/g) was dominant in both investigated extracts. Radical scavenging activity was estimated using colorimetric DPPH and OH radical assays, and both extracts showed prominent and concentration dependent activity with SC50DPPH of 25.25 and 29.38 μg/mL and SC50OH of 16.09 and 17.50 μg/mL, respectively. This is the first report on secondary metabolites and antiradical potential of underground parts of H. naegelianum and H. scheppigianum10th Conference on Medicinal and Aromatic Plants of Southeast European Countries (10th CMAPSEEC), Split, Croatia, 20-24. 05. 2018.Saopštenje sa međunarodnog skupa štampano u izvodu

Influence of Morphology of Sn Dendrites as Sub-layer on Electrolcatalytic Performance of Sn-Pd Electrocatalysts

Sn-Pd electrocatalysts convenient for a possible application in direct ethanol fuel cell were produced by two electrochemical deposition method. In the first step, Sn dendrites of various degree of ramification were electrodeposited by potentiostatically on cathodic potentials of –1200, –1400, –1600 and –1800 mV vs. Ag/AgCl. Electrodeposition of tin was performed from 20 g/l SnCl2 × 2H2O in 250 g/l NaOH electrolyte [1] at the room temperature on Cu electrodes. In the second step, Pd was electrodeposited galvanostatically at a current density of –5 mA cm-2 on the electrodes with electrodeposited Sn dendrites. Electrodeposition of Pd was performed from 1 M NH4Cl and 0.01 M PdCl2 at the room temperature [2]. The processes of electrochemical deposition of Sn and Pd were performed with amounts of the electricity of 400 and 267 mC, giving an atomic ratio synthesized the electrocatalysts of 60 at.% Sn‒40 at.% Pd. Morpological and elemental analysis of the Sn-Pd electrocatalysts was performed by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. The particle size distribution (PSD) was used to estimate a size of Sn dendrites. The electrocatalytic activity of synthesized Sn-Pd electrocatalysts towards ethanol oxidation reaction (EOR) was examined by cyclic voltammetry (CV) and chronoamperometry, using 1 M NaOH with 1 M ethanol solution. Depending on the applied cathodic potentials, the following shapes of dendrites were formed: the needle-like and the spear-like at –1200 mV, an individual fern-like dendrites at –1400 mV, and intertwined network of dendrites of the fern-like shape was formed at cathodic potentials of – 1600 and – 1800 mV vs. Ag/AgCl. The partial coverage of the Sn dendrites through a formation of compact islands of Pd was attained by electrodeposition of Pd on the electrodes with the Sn dendrites. It was shown that morphology of the Sn dendrites as sub-layer strongly correlates the electrocatalytic activity of the Sn-Pd electrocatalysts. The largest electrocatalytic activity showed the Sn- Pd electrocatalyst constructed from the individual fern-like Sn dendrites as sub-layer produced at a cathodic potential of –1400 mV vs. Ag/AgCl. This dendrite type showed more branchy morphology than those obtained at the other cathodic potentials. Formation of individual needle-like and spear-like dendrites at a cathodic potential of – 1200 mV vs. Ag/AgCl did not contribute significantly to the increase of the initial electrode surface area. On the other hand, due to a high nucleation rate, growth a dendrites from one nucleation centre in more directions, as well as the fact that Sn is very soft metal, morphological characteristics of intertwined Sn dendrites obtained at cathodic potentials of −1600 and −1800 mV vs. Ag/AgCl approached to those of compact massive Sn. The partial coverage of Sn dendrites by Pd can be attributed to the current density distribution effect, because Pd electrodeposition process preferentially perfomed at the higher parts of the surface area, i.e. on the dendrites, rather than on the flat part of the electrode surface area. Aside from an influence of degree of branchy of Sn dendrites as sub-layer on the electrocatalytic activity in ethanol oxidation, varios electrocatalytic performance of the Sn-Pd electrocatalysts can also be ascribed to the bifunctional effect

A Novel Two-Step Electrochemical Deposition Method for Sn-Pd Electrocatalyst Synthesis for a Potential Application in Direct Ethanol Fuel Cells

Sn-Pd electrocatalysts with a constant atomic ratio of 60 at.% Sn‒40 at.% Pd suitable for potential application in direct ethanol fuel cells were synthesized using a novel two-step electrodeposition method. First, Sn was electrodeposited in various forms of dendrites, from spear-like and needle-like to individual fern-like dendrites to a network of intertwined fern-like dendrites, by varying the cathodic potential and then performing electrodeposition of Pd at a constant current density in the second step. A morphological and elemental analysis of Sn and Sn-Pd electrocatalysts was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques, while the size of Sn dendrites was analyzed using the particle size distribution (PSD) method. Cyclic voltammetry (CV) and chronoamperometry were applied in order to study the catalytic behavior of Sn-Pd electrocatalysts in the ethanol oxidation reaction (EOR), while CO stripping was used to estimate the antipoisoning capability of the electrocatalysts. The Sn surface morphology of the sub-layer was highly correlated with the electrocatalytic activity of the examined Sn-Pd electrocatalysts. The high activity it presented towards the EOR showed the suitability of the Sn-Pd electrocatalyst constructed from individual fern-like Sn dendrites as a sub-layer. Compared to Pd alone, this Sn-Pd catalyst showed more than 3 times higher activity and improved EOR kinetics. This enhancement in the catalytic activity of the Sn-Pd electrocatalysts is attributed to both the morphological characteristics of Sn as a sub-layer and the bifunctional effect

Copper Electrodeposition onto Palladium from a Deep Eutectic System Based on Choline Chloride

In this work, the electrochemical deposition of copper onto palladium working substrate from ChCl/EG (1:2 ratio) DES electrolyte at 50°C was investigated. Additionally, the Cu(II) electroreduction process was studied by potentiodynamic measurements, cyclic voltammetry, chronoamperometry, in the electrolytes with different concentrations of Cu(II) ions ranging from 0.1 M to 0.5 M

Zn/Au alloys formation by Zn electrodeposition from a deep eutectic system

The electrochemical deposition of Zn onto Au from a choline chloride/ethylene glycol deep eutectic system containing different ZnCl2 concentrations has been investigated. The voltammetric results demonstrated that Zn electrodeposition commences in the zinc underpotential deposition (UPD) and proceeds through to the zinc overpotential deposition (OPD) region. The results of X-ray diffraction analysis revealed that the deposit prepared at a relatively low Zn overpotential of – 0.050 V vs. Zn was composed of cubic AuZn alloy. The morphology of the deposit has been characterized by means of a scanning electron microscope and displays a relatively compact and dendrite-free Zn/Au alloy deposit formed

Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO

We have carried out sub-mm 12CO(J=3-2) observations of 6 giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC) with the ASTE 10m sub-mm telescope at a spatial resolution of 5 pc and very high sensitivity. We have identified 32 molecular clumps in the GMCs and revealed significant details of the warm and dense molecular gas with n(H2) $\sim$ 10$^{3-5}$ cm$^{-3}$ and Tkin $\sim$ 60 K. These data are combined with 12CO(J=1-0) and 13CO(J=1-0) results and compared with LVG calculations. We found that the ratio of 12CO(J=3-2) to 12CO(J=1-0) emission is sensitive to and is well correlated with the local Halpha flux. We interpret that differences of clump propeties represent an evolutionary sequence of GMCs in terms of density increase leading to star formation.Type I and II GMCs (starless GMCs and GMCs with HII regions only, respectively) are at the young phase of star formation where density does not yet become high enough to show active star formation and Type III GMCs (GMCs with HII regions and young star clusters) represents the later phase where the average density is increased and the GMCs are forming massive stars. The high kinetic temperature correlated with \Halpha flux suggests that FUV heating is dominant in the molecular gas of the LMC.Comment: 74 pages, including 41 figures, accepted for publication in ApJ