Preparation and Characterization of Poly(D,L-Lactide-co-Glycolide) Nanoparticles Containing Ascorbic Acid

This paper is covering new, simplistic method of obtaining the system for controlled delivery of the ascorbic acid. Copolymer poly (D,L-lactide-co-glycolide) (DLPLG) nanoparticles are produced using physical method with solvent/nonsolvent systems where obtained solutions were centrifuged. The encapsulation of the ascorbic acid in the polymer matrix is performed by homogenization of water and organic phases. Particles of the DLPLG with the different content of ascorbic acid have different morphological characteristics, that is, variable degree of uniformity, agglomeration, sizes, and spherical shaping. Mean sizes of nanoparticles, which contain DLPLG/ascorbic acid in the ratio 85/150%, were between 130 to 200 nm depending on which stereological parameters are considered (maximal diameters Dmax, feret X, or feret Y). By introducing up to 15% of ascorbic acid, the spherical shape, size, and uniformity of DLPLG particles are preserved. The samples were characterized by infrared spectroscopy, scanning electron microscopy, stereological analysis, and ultraviolet spectroscopy

Comparative analyses of built environment exposures relevant to health of greenhouse gas emissions reduction strategies in Serbia

Paper presents comparative analysis of residential indoor air pollutant concentration change over future specified time horizon, implementing building physical and thermal retrofit measures, thus creating pollution mitigation scenarios for existing Belgrade and Nis housing stock followed by greenhouse gas emission reduction scenarios up to 2050. Regarding specified mitigation scenarios, the set of typical housing unit models has been generated which define existing housing stock of Belgrade and Nis. Extensive monitoring of physical and thermal parameters as well as detailed socio-technical survey of selected households was performed and used as an initial modeling input. Relationship between environment pollution and building performances was investigated, with respect to indoor-outdoor sources of pollution, thermal and physical properties of the stock samples and occupant's behavior. As a final output, indoor pollutant concentrations for each of the modelled cases was obtained and validated against the available data. This housing modelling framework has been created in order to develop an assessment of present and future exposure and health impact quantity regarding single/multiple scenario interventions introduced to the housing stock. This paper provides each strategy guidelines for taking measures towards achieving the healthier indoor environments

Heuristics of Dictionary of technology and the crisis of Yugoslavia 1979-1982 in the context of the rise of postmodern culture

Докторска дисертација ,,Хеуристика Речника технологије и југословенска криза 1979–1982. у контексту успона постмодерне културе” обухвата петогодишње мултидисциплинарно истраживање историјске и тренутне мултикултуралне рецепције Речника технологије у контексту његовог хеуристичког потенцијала. Речник технологије објављен је 1981. као посебан тематски број часописа Видици. али је већ наредне године политички инкриминисан због идеолошког читања његове кодиране херменеутике технологије. Ово истраживање суочава нас са проблемом схватања интелектуалног склопа и разумевања духа времена у коме се Речник технологије појављује. Временски оквир у том смислу обухвата тренутак у коме је објављен, до сада врло оскудно истражен ужи период југословенске кризе (1979–1982), прве одзиве на садржину Речника, као и питање његовог антиципаторског потенцијала. Идеолошка осуда Речника технологије је била толико јака да се протегла и на период после окончања изградње социјализма тако да је провео тридесет и три године у забораву све до 2014. када је организован први научни скуп посвећен дијахронијском сагледавању овог списа што га је поставило у жижу обновљеног теоријског и академског интересовања. Српска хуманистичка мисао о технологији обликовала се још у делу Доситеја Обрадовића, али се та традиција у време друге Југославије скоро потпуно потискује. Зборник Технологија објављен 1980. као теоријска припрема Речника технологије представља обнову овог тока и први зборник филозофије технологије у српској култури. Речник технологије у томе има битно место јер мисли о технологији даје посебне теоријске и практичне одлике које се не могу наћи у списима тог времена. Он је исписан руком и илуминисан што одступа од продукције не само тог времена и парадоксално следи српски премодерни стваралачки канон бавећи се модерном мисли о технологији. Своје тумачење технолошке цивилизације Речник технологије даје кроз хипертекстуалну структуру сто шездесет и две речничке одреднице и разумевање преко сто педесет аутора које наводи. Он даје самосвојну антрополошку перспективу да се есхатологија технологије у неким својим тачкама не разликује од теолошких образаца који у много чему понављају своје премодерне изворе. У томе се огледа одважни постмодерни карактер овог дела који је снажно појачан чињеницом да овај рукопис у складу са средњовековним каноном и постмодерним концептом „смрти аутора” није потписан у отвореном коду. Циљ ове студије је да испита хеуристички потенцијал првог и за сада јединог речника посвећеног цивилизацијском разматрању технологије. Истраживање полази од идеје да сваки преломни историјски тренутак захтева речник који ће кроз разумевање промене парадигме покушати да пружи одговор на из тога произашлу кризу. Речник је у технологији коју не сматра само техничком већ и друштвеном појавом видео кризу личности и стога је разумевање проблема усмерио ка сагледавању језика, филозофије, уметности, теологије и технологије. Због тога га није лако одредити у формалном и значењском смислу и отуда је ово дело било неопходно промислити из перспективе укрштаја низа области и дисциплина. У дисертацији се указује на истовремено национални и универзални карактер Речника технологије што се потврђује у више равни истраживања и остварених научних резултата. Он је испитиван кроз рад на три научне конференције (две националне и једну међународну), кроз два зборника од националног и једног зборника (на енглеском језику) од истакнутог међународног значаја, ауторску изложбу с каталогом уз научну рецензију, документарном филму представљеном у више земаља, неколико научних радова објављених у земљи и иностранству, представљању Речника технологије на домаћим и међународним научним скуповима, као и предавањима у земљи и иностранству. Намера овог вишегодишњег истраживања је да на мултидисциплинарној равни понуди свеобухватно разумевање комплексности Речника технологије полазећи од друштвено-политичке историје до антропологије технологије, обухватајући у ширем смислу политичко, херитолошко-уметничко, социолингвистичко, премодерно- постмодерно, теолошко-технолошко читање овог дела. Рад у том смислу представља и актуелизацију садржаја које доноси Речником и покушај да се кроз његову оптику на крају сагледа матица догађаја који се јављају на обзору нових технологија у контексту успона постмодерне културе краја XX и почетка XXI века.The doctoral dissertation “Heuristics of Dictionary of Technology and the Crisis of Yugoslavia1979–1982 in the context of the rise of postmodern culture” includes five years of multidisciplinary research and evaluation of historical and contemporary multicultural reception of Dictionary of Technology in the light of its heuristic potential. Dictionary of Technology was published in 1981 as a special thematic issue of the journal Vidici, but it was politically supressed the following year due to the ideological reading of its coded hermeneutics of technology. This research needs to address the intellectual context and the spirit of the time Dictionary emerged in. Therefore, the study of Dictionary includes the scarcely researched period of Yugoslav crisis (1979–82), the first responses to its content, as well as the question of its anticipatory potential. The ideological condemnation of Dictionary of Technology was so strong that it extended beyond the end of the construction of socialism. Thus, this document spent thirty-three years in oblivion until 2014 when the first scientific conference dedicated to the diachronic examination of the script happened, placing it in the focus of the renewed theoretical and academic interests. Serbian humanistic thought about technology was shaped initially in the work of Dositej Obradovic, but this tradition was almost completely suppressed during the time of the second Yugoslavia. The volume Technology published in 1980 as a theoretical preparation of Dictionary of Technology represents the renewal of this flow and the first volume of philosophy of technology in Serbian culture. Dictionary of Technology holds a special place in this stream of ideas because it renders technology through special theoretical and practical approaches that cannot be found in the writings of that time. It is handwritten and illuminated which deviates from the production of that time; while addressing the modern thought about technology it paradoxically follows the Serbian premodern creative canon. Interpretation of technological civilization given by Dictionary of Technology has the hypertextual structure of one hundred and sixty-two terms and it refers comprehensively to over one hundred and fifty authors. It gives a distinct anthropological perspective that the eschatology of technology is in some aspects indistinguishable from theological patterns that, in many respects, repeat their premodern sources. This reflects the bold postmodern character of this work, strongly reinforced by the fact that this manuscript was not signed in accordance with the medieval canon and the postmodern concept of “author’s death”. The aim of this study is to examine the heuristic potential of the first and until now the only dictionary dedicated to the civilizational comprehension of technology. The research starts with the idea that every critical historical moment requires a dictionary that tries to respond to the crisis of a paradigm shift by understanding it. By considering technology not only a technical but also a social phenomenon, Dictionary perceived a crisis of selfhood and therefore focused its understanding of the problem on the perception of language, philosophy, art, theology, and technology. Hence, it is not easy to define it in formal and meaning sense, and that is why it was necessary to rethink this work from the perspective of the intersection of a number of fields and disciplines. The dissertation points at the simultaneous national and universal character of Dictionary of Technology, which is confirmed at several levels of the research and scientific results. Dictionary was field tested through three scientific conferences (two national and one international), two national and one internationally recognized publications, an author’s exhibition with a catalogue with scientific review, a documentary presented in several countries, several scientific papers published in the country and abroad, presentation of Dictionary at national and international scientific conferences, as well as lectures at home and abroad. The purpose of this multi-year research is to offer, on a multidisciplinary level, a comprehensive understanding of the complexity of Dictionary of Technology, from socio-political history to anthropology of technology, including in a broad sense political, heritological-artistic, sociolinguistic, premodern-postmodern, theological-technological readings of this work. This work is in this sense also an actualization of the content brought by Dictionary and an attempt to finally look through its optics into the matrix of events occurring on the horizon of new technologies in the context of the rise of postmodern culture of the late 20th and the early 21st century

Atomic swelling upon compression

The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.Comment: 5 pages, 4 figure

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

Multiphysics simulation of corona discharge induced ionic wind

Ionic wind devices or electrostatic fluid accelerators are becoming of increasing interest as tools for thermal management, in particular for semiconductor devices. In this work, we present a numerical model for predicting the performance of such devices, whose main benefit is the ability to accurately predict the amount of charge injected at the corona electrode. Our multiphysics numerical model consists of a highly nonlinear strongly coupled set of PDEs including the Navier-Stokes equations for fluid flow, Poisson's equation for electrostatic potential, charge continuity and heat transfer equations. To solve this system we employ a staggered solution algorithm that generalizes Gummel's algorithm for charge transport in semiconductors. Predictions of our simulations are validated by comparison with experimental measurements and are shown to closely match. Finally, our simulation tool is used to estimate the effectiveness of the design of an electrohydrodynamic cooling apparatus for power electronics applications.Comment: 24 pages, 17 figure

A Sharp Upper Bound on Algebraic Connectivity Using Domination Number

Abstract Let G be a connected graph of order n. The algebraic connectivity of G is the second smallest eigenvalue of the Laplacian matrix of G. A dominating set in G is a vertex subset S such that each vertex of G that is not in S is adjacent to a vertex in S. The least cardinality of a dominating set is the domination number. In this paper, we prove a sharp upper bound on the algebraic connectivity of a connected graph in terms of the domination number and characterize the associated extremal graphs. MSC: 05C35; 05C5

Influence of CAN fertilizer and seed inoculation with NS Nitragin on glycine max plant on pseudogley soil type

Soybean [Glycine max (L.) Merr.] is the most important legume because it is an essential source of dietary protein and oil for animal feed and food production. Good soil with wellplanned program of fertilization is the main factor of soybean production. Soybean yield will be reduced when essential nutrients are deficient. Sufficient soil fertility combined with a well-planned fertilization program is a main component for high soybean production. The aim of this investigation was to estimate the effects of fertilization and seed inoculation on height of soybean plant in humid year. Two factors were tested: 1. CAN fertilization and 2. seed inoculation. Four treatments of CAN fertilization were tested: Control - 0 kg N ha-1; 50 kg N ha-1; 100 kg N ha-1 and 150 kg N ha-1. Two factors of seed inoculation (SI) were tested: Without SI and with SI. Results showed that fertilizers and seed inoculation significantly increased the values of soybean productivity. Cost effective is the application of 50 kg N ha-1 and it is recommended on the basis of this study

Correlation of the liquid mixture viscosities

In this paper forty two selected correlation models for liquid mixture viscosities of organic compounds were tested on 219 binary and 41 ternary sets of experimental data taken from literature. The binary sets contained 3675 experimental data points for 70 different compounds. The ternary sets contained 2879 experimental data points for 29 different compounds. The Heric I, Heric-Brewer II, and Krishnan-Laddha models demonstrated the best correlative characteristics for binary mixtures (overall absolute average deviation < 2%). The Heric I, Heric-Brewer II, Krishnan-Laddha and Heric II models demonstrated the best correlative characteristics for ternary mixtures (overall absolute average deviation < 3%)