Superfluid drag of two-species Bose-Einstein condensates in optical lattices

We study two-species Bose-Einstein condensates in quasi two-dimensional optical lattices of varying geometry and potential depth. Based on the numerically exact Bloch and Wannier functions obtained using the plane-wave expansion method, we quantify the drag (entrainment coupling) between the condensate components. This drag originates from the (short range) inter-species interaction and increases with the kinetic energy. As a result of the interplay between interaction and kinetic energy effects, the superfluid-drag coefficient shows a non-monotonic dependence on the lattice depth. To make contact with future experiments, we quantitatively investigate the drag for mass ratios corresponding to relevant atomic species.Comment: 6 pages, 4 figures. Accepted in its original form but minor changes have been don

Neutral edge modes in a superconductor -- topological-insulator hybrid structure in a perpendicular magnetic field

We study the low-energy edge states of a superconductor -- 3D topological-insulator hybrid structure (NS junction) in the presence of a perpendicular magnetic field. The hybridization of electron-like and hole-like Landau levels due to Andreev reflection gives rise to chiral edge states within each Landau level. We show that by changing the chemical potential of the superconductor, this junction can be placed in a regime where the sign of the effective charge of the edge state within the zeroth Landau level changes more than once resulting in neutral edge modes with a finite value of the guiding-center coordinate. We find that the appearance of these neutral edge modes is related to the level repulsion between the zeroth and the first Landau levels in the spectra. We also find that these neutral edge modes come in pairs, one in the zeroth Landau level and its corresponding pair in the first.Comment: 5 page

Use of linear radiofrequency device in liver resection

Background/Aim. Linear radiofrequency device (LRFD) is disposable tool designed for liver parenchyma transection using controlled radiofrequency to 'seal' blood vessels and bile ducts, making liver resection easier and safer compared to classical resectional techniques. The aim of this study was to determine real value of the LRFD compared to the standard 'keliclasia' technique. Methods. This prospective study analyzed the significant intraoperative parameters and postoperative results of the 200 patients who underwent surgery at the Surgery Clinic of Clinical Centre in Niš, between January 1, 2001, and January 1, 2009. The patients were divided into two groups: the control Keli group (144 patients) with the 'keliclasia' resection technique and the control RF group (with resection performed using LRFD - Tissue Link / Dissection Sealer (DS - 3.0) (56 patients). The following parameters were analyzed: duration of liver ischemia, liver parenchyma transection time, intraoperative blood loss, significant intraoperative and postoperative complication rate, duration of hospitalization and mortality. Results. LRFD was used in 56 liver resections. The average duration of liver ischemia in the RF group was shorter than in the Keli group (7 versus 22 minutes). Parenchymal liver transection was significantly slower in the RF group than in the Keli group (2.05 versus 4.34 cm2/minutes, respectively). There was less intraoperative bleeding using LRFD 'Keliclasia' tehniquethan in the control group (390 mL compared to 420 mL, respectively). After the use of LRFD two cases of biliary leak and 4 pleural effusions were registered. Conclusion. LRFD is simple device for safe liver transection with decreased need for liver ischemia and singificant reducing of the intraoperative blood loss. High price for disposable device and slow parenchyma transection are disadvantages of this device

The importance of quantifying markers of oncogenesis in tissue slices of patients with squamous cell carcinoma of the larynx and chronic laryngitis

Progresija hroničnog laringitisa i nastanak karcinoma larinksa vezan je za aktivaciju različitih onkogena i inaktivaciju tumor supresorskih gena. Proteinski produkti ovih gena se imunohistohemijski detektuju u tkivnim isečcima obolelih pacijenata. Utvrđeno je da karcinomi larinksa sa istim kliničkim i histološkim osobenostima imaju različito biološko ponašanje, a samim tim i prognozu. Hronični laringitisi se karakterišu displazijom koja se može stepenovati u tri stadijuma i kod koje postoji takođe izmenjena ekspresija onkogena i antionkogena. Klinički i histološki nalaz dopunjeni imunohistohemijskim bojenjem tkivnih preparata pružaju dodatnu infomaciju neophodnu u tretiranju hroničnog laringitisa i karcinoma larinksa. Najčešće je izmenjena ekspresija onkogena cyclin D1 i FGF3 kod hroničnog laringitisa i karcinoma larinksa. Od tumor supresorskih gena veoma često su alterisani p16 i p21

Investment project management model of opening open-pit coal mines.

Brze promene u okruženju pred rukovodioce postavljaju mnogobrojne zahteve, pre svega, one koji se tiču ostvarenja ciljeva u zadatom vremenu i raspoloživim sredstvima što zahteva fleksibilan pristup u organizovanju aktivnosti i efikasnost u njihovom sprovođenju. Upravljanje projektima, bilo koje vrste, suštinski, predstavlja veoma složen proces odlučivanja uslovljen velikim brojem ulaznih faktora. Ti faktori treba da omoguće fokusiranje na prioritete i ciljeve, praćenje realizacije, fleksibilnost u prevazilaženju teškoća, prilagođavanje promenama, te kontrolu nad ostvarenim rezultatima. Ovakav način upravljanja zahteva korišćenje proverenih tehnika i alata te timski rad angažovanih na projektu, kako bi se rezultati postigli u planiranom vremenu i sa planiranim sredstvima. Odgovor na ova pitanja su preko svojih metodologija pokušali da daju mnogi autori, poznati svetski instituti za upravljanje projektima, među kojima je i PMI (Project management Institute USA), čije preporuke i smernice su, u značajnoj meri, poslužile kod izrade ove disertacije. U savremenom dobu površinska eksploatacija ležišta mineralnih sirovina, usled velikog broja nepoznanica, obavlja se u sve složenijim uslovima, koje sa aspekta projektovanja, planiranja i pripreme za eksploataciju, te samog procesa odvijanja eksploatacije predstavljaju ograničavajuće faktore. Kada je reč o površinskoj eksploataciji uglja, usled niza specifičnosti koje je odlikuju, navedena problematika postaje još izraženija. Po pravilu, realizacija projekata ovog tipa, predstavlja vrlo složen proces sastavljen od višedimenzionalnih aktivnosti ispitivanja svih relevantnih determinanti budućih stanja i promena koje projekat nosi sa sobom. Sa druge strane, razvoj i nova saznanja u drugim naučnim oblastima na koje se oslanja rudarska nauka, pružaju sve šire mogućnosti njene primene.Rapid changes in the environment set numerous requirements before the managers. The aforementioned requirements are primarily related to the achievement of objectives within the given time and resources available, which requires a flexible approach to organisation of activities and efficiency in their implementation. Project management of any kind, is essentially a very complex decision-making process conditioned by a large number of input factors. Such factors should allow to focus onto the priorities and objectives, to monitor the implementation, provide flexibility in overcoming any difficulties, enable adaptation to changes and provide control over the results obtained. This management method requires the use of proven techniques and tools, as well as of teamwork involved in the project in order to achieve the results within the planned time and by using planned resources. The answer to these questions was sought and given, via various methodologies, by many authors, world-renowned project management institutes, including the PMI (Project Management Institute, USA), whose recommendations and guidelines have been used, to a significant degree, in the preparation of this dissertation. In modern times, surface mining of mineral deposits, due to the large number of unknowns, is performed in increasingly complex conditions which in terms of design, planning, mining preparation and the mining process represent the limiting factors. When it comes to surface coal mining, due to a number of specific features characterising it, the above problems become even more pronounced. As a rule, the implementation of such projects is a very complex process consisting of multidimentional testing activities of all relevant determinants of future conditions and changes that the project entails. On the other hand, the development and new knowledge in other scientific areas the mining science relies on, provide continuously expanding possibilities of its application. Taking all theabove into account, the standard approach of project management cannot fully provide for all the complexity of mining projects. Therefore, it is required..

Synthesis and characterization of some water-soluble starch derivatives

Predmet istraživanja ove doktorske disertacije bila su dva tipa derivata skroba: anjonski i katjonski skrob. Za sintezu anjonskog skroba (karboksimetil-skrob) korišćena je monohlorsirćetna kiselina (ili njena natrijumova so), a za sintezu katjonskog skroba korišćen je 3-hlor-2-hidroksipropil-trimetilamonijum hlorid. U prvom delu rada ispitivan je uticaj reakcionih uslova i količine reagenasa na stepen supstitucije i granični viskozitetni broj karboksimetil-skroba. Na osnovu dobijenih rezultata određeni su optimalni uslovi pod kojima je sintetisano šest uzoraka karboksimetil-skroba – tri uzorka su pripremljena od skroba iz krompira, a tri od skroba iz kukuruza. Stepen supstitucije sintetisanih uzoraka je iznosio od 0.40 do 1.10. Uzorcima karboksimetil-skroba ispitivana su svojstva u razblaženim rastvorima upotrebom viskozimetrije, statičkog i dinamičkog rasipanja svetlosti. Kao rastvarač korišćeni su voda i rastvori natrijum hlorida u vodi. Za svaki uzorak određene su vrednosti molarne mase po masenoj zastupljenosti, MW, poluprečnika rotacije, Rg, hidrodinamičkog poluprečnika, Rh, i graničnog viskozitetnog broja, [η]. Utvrđeno je da u rastvorima soli poreklo skroba i stepen supstitucije (u ispitivanom opsegu) ne utiču na oblik i unutrašnju strukturu makromolekula. Svojstva u razblaženim rastvorima natrijum-hlorida zavise samo od jonske jačine rastvarača. Ispitivanje termičke stabilnosti sintetisanih uzoraka karboksimetil-skroba termogravimetrijskom analizom pokazalo je da porast temperature ima specifičan uticaj na osobine karboksimetil-skroba zavisno da li se on nalazi u kiselom obliku ili u obliku soli. Temperature na kojima dolazi do gubitka 5 i 50 mas.% su nezavisne od stepena supstitucije kod uzoraka karboksimetil-skroba u obliku soli, dok kod uzoraka karboksimetil-skroba u kiselom obliku postoji linearna zavisnost ovih temperatura od stepena supstitucije. Uzorcima su određene i energije aktivacije termičke degradacije i pokazalo se da je energija aktivacije termičke degradacije uzoraka karboksimetil-skroba u obliku soli niža, a energija aktivacije termičke degradacije uzoraka karboksimetil-skroba u kiselom obliku viša od energije aktivacije termičke degradacije nemodifikovanog skroba. Katjonski derivat je pripremljen modifikacijom skroba iz kukuruza. Sintetisan je jedan uzorak katjonskog skroba od koga su kontrolisanom ultrazvučnom degradacijom pripremljena još četiri uzorka. Vrednosti molarne mase po masenoj zastupljenosti, MW, poluprečnika rotacije, Rg, hidrodinamičkog poluprečnika, Rh, i raspodele molarnih masa uzoraka, su određene upotrebom gel-propusne hromatografije, statičkog i dinamičkog rasipanja svetlosti. Utvrđeno je da se sa povećanjem vremena ultrazvučne degradacije smanjuje molarna masa uzoraka uz istovremeno suženje raspodele molarnih masa. Ultrazvučnom degradacijom dobijeni su makromolekuli čiji oblik i unutrašnja struktura nisu međusobno slični. Na osnovu podataka dobijenih metodom statičkog rasipanja svetlosti utvrđeno je da nedegradirani katjonski skrob ima kompaktniju strukturu i u vodi i u rastvorima soli od odgovarajućih uzoraka karboksimetil-skroba. Takođe, na osnovu ispitivanja zavisnosti viskoznosti od brzine smicanja koncentrovanih rastvora katjonskog skroba, kao i karboksimetil-skroba u vodi kao rastvaraču utvrđeno je da katjonski skrob ima nižu viskoznost od uzorka.The investigation of two type of starch derivates - anionic and cationic starch – is described in this thesis. Mono-chlor-acetic acid (or its sodium salt) was used for synthesis of anionic starch while its cationic derivate was synthesized by the use of 3-chlor-2-hidroxypropyl-N,N,N-trimethylamonium chloride. The experiments focused on the influence of reaction conditions and the amount of reagents on the degree of substitution and limiting viscosity number of carboxymethyl starch are presented in the first part of the thesis. According to the obtained results the optimal conditions for the starch carboximetilation were defined. Six samples of carboxymethyl starch differing in the degree of substitution (ranging from 0.4 to 1.1) were synthesized under previously defined optimal conditions – corn or potato starch were used as starting material for the synthesis of carboxymethyl starch. The properties of carboxymethyl starch were further examined in diluted solutions by means of viscometry, static and dynamic light scattering. Water and sodium chloride dissolved in water were used as solvent. Weight-average molecular weight, MW, radius gyration, Rg, hydrodynamic radius, Rh, i limiting vicosity number, [η] were determined for each sample. It was shown that starch origin and degree of substitution (within the investigated range) did not affect the shape and the internal structure of macromolecules in salt solution. Properties of macromolecules in diluted solutions depended only on the solvent ionic strength. The influence of temperature on acidic and salt form of carboxymethyl-starch was also analyzed. Thermogravimetric analysis showed that there are some differences in the behavior of these carboxymethyl starch forms. In salt form, temperatures needed for 5 or 50 mas.% weight loss were independent on degree of substitution in analyzed caboximethylstarch samples while a linear dependence of temperature on degree of substitution were recorded for samples of carboxymethyl-starch in acid form. Comparing to unmodified starch, activation energy of thermal degradation for salt form of carboxymetyl starch was lower while it was higher for carboximethyl-strach acidic form. Finally, cationic derivate was prepared by modification of corn-originated starch. One sample of cationic starch was synthesized and four additional samples were prepared by its controlled ultrasonic degradation. Diluted solutions of cationic starch samples were investigated by gel-permeability chromatography, static and dynamic light scattering. Weight-average molecular weight, MW, radius gyration, Rg, hydrodynamic radius, Rh, and molar mass distribution were determined for each sample. It was shown that: 1) duration of ultrasonic degradation inversely correlated to sample molar mass; 2) increase in duration of ultrasonic degradation resulted in narrowing of the molar mass distribution. Changes in the internal structure of macromolecules that depended on duration of ultrasonic degradation were also observed. Comparison of synthesized cationic starch with samples of carboxymethyl starch showed that in both water and salt solutions cationic starch has more compact structure. It was also shown that viscosity of concentrated cationic starch solution was lower than viscosity of solution of carboxymetyl starch having similar molar mass. However, concentrated cationic starch solution showed more pronounced pseudoplastic behavior

The review of some novel biomarkers in sedimentary organic matter

A series of novel C33-C35 hexacyclic benzohopanes have been identified in coals and crude oils of different ages from all over the world [1]. They differ from regular benzohopanes by the presence of methyl group in position C-31. These compounds are more abundant in coals and terrestrial oils. The investigation also showed that mature samples have distributions of benzohopanes distinct from immature ones, which are characterised by a greater number of benzohopane isomers. Although exact structures of the additional isomers were not determined, it seems they were formed by an isomerisation of alkyl groups attached to the aromatic ring. Two novel monoaromatic hydrocarbons (MW = 270; basic fragment ions m/z 255 and 146) were identified in coals, mudstones and crude oils. Their structures were determined as cis- and transicetexa-8,11,13-trienes (or dehydroicetexanes) using NMR spectroscopy. Dehydroicetexanes are potential biomarkers of Cupressaceae (cypress conifers). Benzo[b]naphtho[d]furans (BNFs) have been identified in oils, condensates, source-rocks, coals and coaly shales, being more abundant in the latter. We detected BNFs (m/z 218) in relatively high amounts in the aromatic fractions of pyrolysates of brown coals which attained the maturity corresponding to vitrinite reflectance of 1.80 %Rr [2]. This result suggests that BNFs can be attractive for investigations of mature fluids that originate from gas/condensate prone sources, rich in type III kerogen, which are usually depleted in biomarkers. Recently, it was observed that [2,1]/[1,2]BNF ratio can be used to describe lithofacies [3]. This ratio is much lower in sediments from fluvial-deltaic systems than in clay-depleted sediments from marine environments. 1-Chloro-n-alkanes (m/z 91) have been identified in saltmarsh vegetation, recent sediments from estuarine setting and freshwater lake sediments [4]. Despite their absence in the investigated crude oils, we identified a series of 1-chloro-n-alkanes in pyrolysates of the corresponding asphaltenes, obtained at 250 oC. This result indicates very good preservation of biomarkers occluded inside asphaltenes and announces a possible application of 1-chloro-n-alkanes in correlation studies.Invited Lectur

Characteristics of Phomopsis sp. isolates of plum trees origin

Twelve isolates of Phomopsis sp. were obtained from the branches and the trunk of plums (Prunus domestica L) with decay symptoms in Valjevo, Ljig Koceljeva and Ub vicinity during 2004-2006. Morphological, pathogenic and growing characteristics were studied. Pathogen caused tissue necrosis of branches around the inoculate seats, and wrinkling and watering of plum fruits. All media were suitable for pathogen development, except prune agar. The best growth of isolates was at medium pH 5,5. The optimal temperature for growth and germination of pycnidiospores was 25°C

Organic geochemistry of crude oils from the turija oil field (SE Pannonian Basin, Serbia)

The Turija oil field, being an important oil field in Serbia, is located in the Banat Depression of the southeastern part of the Pannonian Basin. Oil samples from the Turija oil field were investigated in order to estimate origin, depositional environment, thermal maturity and age of the corresponding source rocks. For that purpose, a comprehensive analysis of biomarkers and aromatic compounds was performed. n-Alkanes are predominant compounds in the total ion chromatograms of saturated fractions of all samples, showing that Turija oils are not biodegraded. The distributions of n-alkanes, which are characterised by equivalent abundances of long- and short-chain homologues and maximums at C17, C21 and C27, suggest a mixed aquatic-terrestrial origin. The uniform distributions of regular C27-C29 5α(H)14α(H)17α(H) 20(R) steranes support the previous assumption. The presence of oleanane in all samples is indicative for a contribution of angiosperm plants to the precursor organic matter (OM). Furthermore, the presence of this biomarker implies the Upper Cretaceous or younger age of the corresponding source rocks. Isoreniratane and its derivatives have been identified in all samples. Although isorenieratane can originate from β-carotene, which is widespread in algae, bacteria and terrestrial plants, the presence of other catagenetic products of isorenieratene (mass fragmentogram m/z 133 of the aromatic fraction) unambiguously confirms a contribution of green sulphur bacteria Chlorobiaceae to the precursor organic material [1]. The pristane to phytane (Pr/Ph) ratio ranges from 0.64 to 1.17, indicating reducing to dysoxic conditions during the deposition of precursor OM. The presence of the above mentioned isorenieratane derivatives implies the photic zone of anoxia. The stratification of water column is also supported by the presence of gammacerane and values of gammacerane index, GI = gammacerane x 10/(gammacerane + C30 17α(H)21β(H)-hopane) > 1 in almost all the samples. Alkylated 2-methyl-2- (4,8,12-trimethyltridecyl) chromans (MTTCs) were detected in all studied oils. A predominance of 5,7,8-trimethyl-MTTC over 5,8-dimethyl-MTTC, 7,8-dimethyl-MTTC and 8-methyl-MTTC, associated with the values of MTTC ratio (MTTC = 5,7,8-trimethyl-MTTC/ΣMTTCs) in 0.44 to 0.65 range, indicates deposition of OM in a brackish environment [2]. The maturity of Turija oils was determined using typical sterane and hopane isomerisation maturity parameters and methyldibenzothiophene ratio, MDBTR = 4-MDBT/1-MDBT [3]. The obtained results indicate that Turija oils were generated in an early stage of oil window

Testing the effectiveness of work in the Balint group in developing empathy and preventing the burnout syndrome of doctors

Ciljevi ovog istraživanja su bili ispitavanje da li je učestvovanje u Balint grupama povezano sa većim stepenom empatije i smanjenjem sindroma sagorevanja lekara, kao i ispitivanje psihometrijskih karakteristika upitnika za empatiju, Interpersonal Reactivity Index (IRI), uključujući lingvističku validaciju i kulturološku adaptaciju srpske verzije upitnika. Metod: Ovo istraživanje je obuhvatilo 210 lekara iz primarne zdravstvene zaštite. Od 210 lekara, 70 je završilo Balint edukaciju u trajanju od minimum godinu dana, dok 140 lekara nije pohađalo pomenutu edukaciju. Za svakog doktora sa završenom Balint edukacijom metodom slučajnog izbora izabrana su po dva lekara koja nisu završila ovu edukaciju, a koja rade u istom domu zdravlja i imaju istu poziciju (lekar opšte medicine ili specijalista). Kriterijumi za isključivanje iz studije za obe grupe lekara su bili sledeći: lekari koji su bili na bolovanju ili odmoru najmanje mesec dana pre prikupljanja podataka, koji su imali prekid u radu duže od jedne godine (usavršavanje u inostranstvu, dugotrajna bolest ili česte promene posla u poslednjih pet godina) i koji su bili izloženi većoj fizičkoj ili psihičkoj traumi van posla (bolest ili smrt u porodici, razvod, itd.). Za potrebe ovog istraživanja, konstruisan je opšti upitnik za ispitanike i korišćena su još dva dodatna upitnika, za ispitivanje empatije-Davisov „indeks interpersonalne reaktivnosti“ (IRI) i Maslach upitnik za procenu sindroma sagorevaja na poslu (MBI). U statističkoj obradi podataka su korišćene metode deskriptivne statistike, Studentov t-test, Pearson-ov hi-kvadrat test, Spearman-ov koeficijent korelacije, metode logističke i ordinalne regresije, Cronbach-ov koeficijent alfa, intraklasni koeficijent korelacije, kao i faktorska analiza. Rezultati: Preko tri četvrtine (82,9%) lekara u našem uzorku je bilo ženskog pola, dok je 17,1% ispitanika pripadao muškom polu. Srednja vrednost godina starosti ispitanika je iznosila 48,3±9,6 i kretala se od 30 do 65 godina. Lekari koji su završili Balint edukaciju su imali značajno veće skorove na subskalama Zauzimanje tuđeg stanovišta, Fantazija i Empatijska brižnost u odnosu na lekare koji je nisu završili, p<0,001. Što se tiče subskale Lična nelagodnost, nije bilo statistički značajne razlike između lekara ove dve grupe, p=0,530...The aim of our study was to examine whether the participation in Balint group is associated with a higher degree of empathy and reduced burnout syndrome amongst primary health care doctors, as well as testing the psychometric characteristics of empathy questionnaire, Interpersonal Reactivity Index (IRI), including the linguistic validation and cultural adaptation of the Serbian version of the questionnaire. Methods: This investigation was conducted on a population of 210 doctors employed in primary health centers in Belgrade. Of 210 doctors, 70 have completed Balint training for a period of at least one year, whereas 140 doctors have never attended this training (Non-Balint group). Each doctor who completed Balint education, was grouped with two other randomly chosen Non-Balint doctors, who worked at the same health center and had the same level of education (general practitioner or specialist). Exclusion criteria for both groups related to doctors on sick leave or holiday absence at least 1 month prior to the data collection period, who have not worked for more than 1 year (prolonged studies abroad, prolonged illness, or various and frequent changes in the workplace over the past 5 years), and with exposure to increased mental or physical trauma outside of work (death or disease in the family, divorce, etc.). For the purposes of this research, a general questionnaire was drafted and two additional questionnaires used, one to test the empathy-Davis' IRI and the other to measure the burnout-Maslach Burnout Inventory (MBI). The statistical analysis used descriptive statistics, Student’s t-test, Pearson's hi-square test, Spearman's correlation coefficient, logistic and ordinal regression methods, Cronbach alpha, intraclass correlation coefficient, and factor analysis. Results: Over three quarters (82.9%) of doctors in our sample were females, while 17.1% thereof were male doctors. The mean age of the respondents was 48.3 ± 9.6 and ranged from 30 to 65 years. Doctors who completed Balint education had significantly higher scores on subscales Perspective Taking, Fantasy and Empathic Concern compared to doctors who did not complete it, p<0.001..