Quality monitoring at fusion welding of polyethylene high-density pipes

The paper presents the main parameters of fusion welding and their Off - line analysis of Polyethylene high-density (PE-HD) pipes. By direct measurements of voltage and current at the coupler, inductive and the resistant character changes in amplitude modulation waveforms of the measured signal are observed. In early measuring device analyzes the scanned parameters with certain types of fittings and compares them with the tested and measured parameters is done by welding machines. There can be seen the time delay or “dead time” when the system analyzes the parameters and dimensioned regulatory function of the system

Mechanisms of scavenging monoaromatic hydrocarbons (BTEX) from ambient air by wet deposition

Lako isparljiva organska jedinjenja predstavljaju jednu od najznačajnijih klasa jedinjenja koja se sa površine Zemlje emituju u troposferu. Monoaromatični ugljovodonici, benzen, toluen, etilbenzen i izomeri ksilena (BTEX) su lako isparljiva organska jedinjenja koja dominiraju u urbanim i industrijski razvijenim sredinama i mogu se smatrati nosiocima zagađenja poreklom iz antropogenih izvora. Pored činjenice da se BTEX, nakon zabrane korišćenja tetraetil olova, masovno koriste kao aditivi bezolovnim motornim benzinima, postoje i brojne druge antropogene aktivnosti koje dovode do njihove emisije u troposferu. Zbog činjenice da su BTEX zagađujuće supstance koje mogu imati direktan negativan uticaj na zdravlje ljudi i životnu sredinu, kao i indirektan, formiranjem zagađujućih supstanci druge generacije, od posebnog značaja je da se što bolje istraže svi procesi koji dovode do njihovog uklanjanja iz troposfere. U skladu sa tim, osnovni cilj ove disertacije bio je da se utvrde mehanizmi uklanjanja BTEX iz ambijentalnog vazduha mokrom depozicijom...Volatile organic compounds (VOC) are one of the most important classes of compounds emitted to the troposphere from the Earth surface. Monoaromatic hydrocarbons, benzene and its alkyl derivates - toluene, ethylbenzene,and isomers of xylene, also known as BTEX, are the most abundant among VOC emitted in urban and industrially developed areas, and are often used as indicators of man-made pollution. Besides being present in vehicle exhaust as a result of BTEX being petrol additives as well as fossil fuel combustion products, BTEX are emitted from other sources related to anthropogenic activities. BTEX have direct adverse effect on human health and environment, as well as indirect, due to a fact that they are being important photochemical precursors for the formation of the second generation of pollutants, which is why it is very important to better understand all of the processes leading to BTEX removal from ambient air. Accordingly, the aim of this dissertation was to determine mechanisms of BTEX scavenging from ambient air by wet deposition..

Phytochemical and genetical variability of species from section Serpyllum (Mill.) Benth. genus Thymus L. (Lamiaceae) in Serbia

Rod Thymus je po broju vrsta jedan od najznaĉajnijih u okviru familije Lamiaceae. U zavisnosti od pristupa autora broj vrsta unutar roda varira, meĊutim ukoliko se izabere pristup minimalne varijabilnosti, prema raspoloţivim podacima opisano je 215 vrsta ovog roda. Vrste ovog roda podeljene su u osam sekcija. U flori Srbije opisana je, do sada, 31 vrsta i preko 100 infraspecijskih taksona, koje sve pripadaju podsekciji Serpyllum, sa izuzetkom vrsta Thymus comptus i Th. striatus (Sect. Hyphodromi) i Th. vulgaris (Sect. Thymus). Reproduktivna izolacija izmeĊu vrsta ovog roda je izuzetno slaba što ĉini taksonomska istraţivanja još teţim. Vrste roda Thymus koriste se kao lekovite i aromatiĉne biljke u tradicionalnoj i zvaniĉnoj medicini u svim krajevima u kojima se javljaju. Cilj ovog rada je bio da se opišu razliĉiti hemotipovi unutar vrsta i populaciju ovog roda kao i da se analizom površinskih flavonoida i AFLP markera poboljša uvid u genetiĉke i evolutivne odnose izmeĊu populacija vrsta ovog roda sa podruĉja Srbije. U ovo istrţivajne ukljuĉene su populacije vrsta Th. pulegioides (Subsect. Alternantes), Th. glabrescens, Th. maschallianus i Th. pannonicus (Subsect. Isolepides), Th. balcanus i Th. praecox (Subsect. Peudomarginati) Analiza sastava etarskih ulja vršena je pomoću TD-GC-MS sistema, a jedinjenja su odreĊen uporeĊivanjem RI i/ili masenog spektra sa literaturnim podacima. Identifikovana su ukupno 103 jedinjenja. Identifikovane su, po brojnosti, tri glavne grupe jedinjenja: seskviterpenski ugljovodonici, oksigenovani monoterpenski ugljovodonici i monoterpenski ugljovodonici. Statistiĉka obrada sastava etarskih ulja ukljuĉila je korelacije, analizu glavnih komponenti i klaster analizu. Statistiĉka obrada je pokazala da se, po relativnoj zastupljenosti jedinjenja, mogu razlikovati geraniolni, fenolni, germakren-D, citralni, linaloolni, (E)-kariofilen, α-terpinil acetat i linalil acetatni hemotip.In terms of the number of species, the genus Thymus is one of the most important genera within the Lamiaceae family. The number of species may vary depending on the approach of the author, but if the concept of minimal variability is chosen 215 species have been described. This genus is divided into 8 sections. In Flora of Serbia, 31 species and more than 100 ifraspecific taxa have been described, all of which belong to section Serpyllum, except Thymus comptus and Th. striatus (Sect. Hyphodromi) and Th. vulgaris (Sect. Thymus). Reproductive isolation between species seems to be weak, which makes taxonomical studies in this genus even more difficult. Species of genus Thymus are used as aromatic and medicinal plants in both traditional and modern medicine in all regions where they grow. The aim of this work was to describe different chemotypes within species and population of this genus and, by analysis of surface flavonoids and AFLP markers, provide better insight into genetic and evolutional relationships among the populations and species of the genus Thymus from Serbia. This work included populations of Th. pulegioides (Subsect. Alternantes), Th. glabrescens, Th. maschallianus and Th. pannonicus (Subsect. Isolepides), Th. balcanus and Th. praecox (Subsect. Peudomarginati). Analysis of essential oils was done by TD-GC-MS system, and compounds were identified by comparing RI and/or mass spectra with published data. 103 compounds were identified. Three major group of essential oil compounds were identified: monoterpene hydrocarbons, oxygenated monoterpene hydrocarbons and sesquiterpene hydrocarbons. Based on relative abundance of compounds, Corelation, PCA and Cluster analysis were performed, and it revealed the existence of several chemotypes, such as geraniol, phenol, germacrene-D, citral, linalool, (E)-caryophyllene, α-terpinyl acetate and linalyl acetate chemotype

Modeling-based Development of an Enantioselective Hydrogenation Reaction of a Sitagliptine Intermediate

This work presents a quality by design (QbD) driven approach to the plan of experiments and reaction modeling that was effective in obtaining enhanced process knowledge and defining a design space for an active pharmaceutical ingredient (API) manufacturing process. Engineering aspects of the process were explored by process modeling using computer predictive process simulators. QbD approach is presented on a case study of the process development of the sitagliptine synthesis step. The process involves an enantioselective hydrogenation step. Based on the proposed reaction mechanism and by combining the heat and mass transfer, thermodynamics, and the kinetics of the reactions, the API quality specifications (enantiomeric purity, impurity levels) are described across the modeling of process space. This process space was defined through target specifications, practical operating conditions for scale-up, and plant control capabilities. Model predictions were verified with results obtained in the laboratory, and at pilot plant scale

Nadzor kvalitete elektrofuzijskog zavarivanja polietilenskih cijevi visoke gustoće

The paper presents the main parameters of fusion welding and their Off - line analysis of Polyethylene high-density (PE-HD) pipes. By direct measurements of voltage and current at the coupler, inductive and the resistant character changes in amplitude modulation waveforms of the measured signal are observed. In early measuring device analyzes the scanned parameters with certain types of fittings and compares them with the tested and measured parameters is done by welding machines. There can be seen the time delay or “dead time” when the system analyzes the parameters and dimensioned regulatory function of the system.U radu se prikazuju glavni parametri fuzijskog zavarivanja te njihova Off – line analiza PE-HD cijevi. Izravnim mjerenjem napona i struje na spojnici induktivnog i djelatnog karaktera uočene su promjene u amplitudnoj modulaciji valnih oblika mjerenih signala. Početkom mjerenja uređaj analizira skenirane parametre sa pojedine vrste spojnice i uspoređuje ih sa ispitanim i izmjerenim parametrima koje je odradio sam uređaj za zavarivanje. Upravo se tu vidi zadrška u vremenu tzv. „mrtvo vrijeme“ kada sustav analizira parametre i dimenzionira sustav regulatorske funkcije

Supplementary data for article: Sostaric, A.; Stojic, S. S.; Vukovic, G.; Mijic, Z.; Stojić, A.; Gržetić, I. Rainwater Capacities for BTEX Scavenging from Ambient Air. Atmospheric Environment 2017, 168, 46–54. https://doi.org/10.1016/j.atmosenv.2017.08.045

Supplementary material for: [ https://doi.org/10.1016/j.atmosenv.2017.08.045]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2539]Related to accepted version:[http://cherry.chem.bg.ac.rs/handle/123456789/3007

Overview of carotenoids distribution among wild plant species of the Balkan Peninsula

The Balkan Peninsula is characterized by a great diversity of flora and vegetation. Moreover, it is native to a large number of wild plant species containing carotenoids, biologically active compounds, beneficial for human health. Carotenoid pigments exhibit a great antioxidant and anti-inflammatory effect, in addition to beneficial impact on eye health, heart, blood vessels, cognitive function and antiaging. Nevertheless, their role has been scientifically proven in prevention and treatment of cancer. The aim of the research was to form a database on carotenoid plants of Serbia and the Balkans that is set up electronically for easy access, management and updating. The research included the analysis and organization of information on collected plants, as well as literature data related to the traditional use and storage of plants and plant parts and products rich in carotenoids in fresh, dried or canned state. Sixty wild plants from more than ten plant families were registered to contain these antioxidant pigments. Among them three endemic species namely Lilium bosniacum (Beck) Fritsch (lily native to Bosnia and Herzegovina), Ramonda nathaliae Pančić & Petrović and R. serbica Pančić were inscribed, of which the last two are Tertiary relicts. The type and level of carotenoids varied depending on the plant species and organs including leaves, petals, immature and ripe fruits, pulp, seeds, etc. According to database, fruits were the richest source of these pigments. Reported carotenoid content, included both xanthophylls and carotenes, whereas lutein and β-carotene were predominantly major compounds in berries and flowers respectively. Total carotenoid content, determined by HPLC method, was the highest in fresh berries of Rubus fruticosus L. (440 μg/100g

Supplementary data for article: Sostaric, A.; Stojic, S. S.; Vukovic, G.; Mijic, Z.; Stojić, A.; Gržetić, I. Rainwater Capacities for BTEX Scavenging from Ambient Air. Atmospheric Environment 2017, 168, 46–54. https://doi.org/10.1016/j.atmosenv.2017.08.045

Supplementary material for: [ https://doi.org/10.1016/j.atmosenv.2017.08.045]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2539]Related to accepted version:[http://cherry.chem.bg.ac.rs/handle/123456789/3007

On the status of music and musical instruments in Arabic culture after the advent of Islam

This article bases its arguments mainly on data found in secondary literature about the propriety of music in Arabic culture after the advent of Islam. One of the oldest sources in Arabic on the subject is Damm al-malāhī (The Condemnation of Instruments of Diversion). In it, the author, Ibn Abī al-Dunyā (823-894) condemned listening to music and musical instruments. Subsequently, many books addressed the question of whether music is illicit (ar. harām). Western scholars defined this corpus of literature as a kind of polemic about the permissibility of music and musical instruments in Islamic culture. Since there is no verse (ar. Áya) in the Qur’Án which explicitly forbids or allows music, and since, at the same time, the hadīt literature abounds with contradictory statements about the practice of the prophet Muhammad regarding listening to music and musical instruments, this question continues to resurface, either in the media or on web pages specifically devoted to the issue. This topic is also quite interesting in terms of the reflexions one can encounter in the Muslim areas of the ex-Yugoslav region. At the same time, the article touches upon the special place that the Qur’ān recitation (ar. tilāwat al-Qur’ān) and Islamic call to prayer (ar. adān) have in Muslim communities. We often find both of them in chapters on religious music, and can, for instance, hear Gorans from Kosovo say (colloquially) that one sings the call to prayer. Nevertheless, although both the Recitation and the call to prayer employ the system of maqāms found in secular forms of music, in religious Islamic circles they have never been defined as music, nor are they understood as such in Islamic public opinion. It has been said innumerable times that it is not the (listening to) music per se that is forbidden, but rather the circumstances surrounding music, sometimes associated with the consumption of alcohol or similar behaviour, which leads to transgression of Islamic ethical norms. And even though music - as suggested by Henry George Farmer-was to be found in the private, public, and religious life of the Arabs from pre-Islamic times to the present (Farmer 1967: 17), and even despite it not being forbidden in Islam, the status of the professional musician was never truly regarded as respectable

Mechanisms of scavenging monoaromatic hydrocarbons (BTEX) from ambient air by wet deposition

Lako isparljiva organska jedinjenja predstavljaju jednu od najznačajnijih klasa jedinjenja koja se sa površine Zemlje emituju u troposferu. Monoaromatični ugljovodonici, benzen, toluen, etilbenzen i izomeri ksilena (BTEX) su lako isparljiva organska jedinjenja koja dominiraju u urbanim i industrijski razvijenim sredinama i mogu se smatrati nosiocima zagađenja poreklom iz antropogenih izvora. Pored činjenice da se BTEX, nakon zabrane korišćenja tetraetil olova, masovno koriste kao aditivi bezolovnim motornim benzinima, postoje i brojne druge antropogene aktivnosti koje dovode do njihove emisije u troposferu. Zbog činjenice da su BTEX zagađujuće supstance koje mogu imati direktan negativan uticaj na zdravlje ljudi i životnu sredinu, kao i indirektan, formiranjem zagađujućih supstanci druge generacije, od posebnog značaja je da se što bolje istraže svi procesi koji dovode do njihovog uklanjanja iz troposfere. U skladu sa tim, osnovni cilj ove disertacije bio je da se utvrde mehanizmi uklanjanja BTEX iz ambijentalnog vazduha mokrom depozicijom...Volatile organic compounds (VOC) are one of the most important classes of compounds emitted to the troposphere from the Earth surface. Monoaromatic hydrocarbons, benzene and its alkyl derivates - toluene, ethylbenzene,and isomers of xylene, also known as BTEX, are the most abundant among VOC emitted in urban and industrially developed areas, and are often used as indicators of man-made pollution. Besides being present in vehicle exhaust as a result of BTEX being petrol additives as well as fossil fuel combustion products, BTEX are emitted from other sources related to anthropogenic activities. BTEX have direct adverse effect on human health and environment, as well as indirect, due to a fact that they are being important photochemical precursors for the formation of the second generation of pollutants, which is why it is very important to better understand all of the processes leading to BTEX removal from ambient air. Accordingly, the aim of this dissertation was to determine mechanisms of BTEX scavenging from ambient air by wet deposition..