Air stream velocity modelling in multichannel spiral cyclone separator

Numerical modelling problem is investigated in a gas aerodynamics multichannel spiral cyclone separator with a tangential inflow. Experimental and theoretical papers analysing cyclone separator with particularly complex turbulent flow were reviewed. The three-dimensional transport differential equations for incompressible laminar and turbulent flow inside the cyclone separator were presented. They were numerically solved by finite volume method using the Re-Normalisation Group (hereinafter RNG) k-ε turbulence model. The numerical air flow movement was modelled in cyclone separator with the following dimensions: 0.95 m height, 0.330 m diameter, 0.88 m height of spiral-cylindrical part, 0.39 m height of conical part, inflow dimensions (on the side of cylindrical part) according to the drawings were a × b = 28 × 95 mm. The mathematical model of air flow movement in cyclone separator was composed by Navier-Stokes (Reynolds) as the three-dimensional differential equation system. The modelling results were obtained by the tangential and axial velocity profiles in cyclone separator using RNG k-ε turbulence model, the inflow velocity from 4.1 m/s to 15.4 m/s coincided well with the experimental results. This is the first article testing for multichannel cyclone and determined distributions of aerodynamic parameters. The absolute error between experimental and modelling results changed from 0.01 to 0.24 units

Noise level study and assessment in the southern part of Panevežys

Noise is a relevant problem faced not only by Lithuania but across the world. With motor traffic flow increase, the noise caused by them is also growing and in particular noisy are heavy vehicles and motorcycles. Noise measurements were taken near the main streets in the southern part of Panevežys. Measurements were made during three time periods of the day: in the daytime (from 6 a.m. to 6 p.m.), in the evening (from 6 p.m. to 10 p.m.) and at night (from 10 p.m. to 6 a.m.). In this part of the city noise is mainly generated by cars. The measured noise levels were compared with the noise level limit (NLL) in the measurement places where the NLL is most often exceeded. Noise level analysis and traffic flows are presented in the work. As the performed measurements show, the NLL in the daytime was exceeded by 65%, in the evening by 88%, and at night by 71% of all the total measurements made. The equivalent NLL was exceeded by up to 14 dBA and the maximum NLL – by up to 17 dBA. The highest excess of the NLL was recorded by streets with the heaviest traffic. Santrauka Triukšmas – ne tik Lietuvoje, bet ir visame pasaulyje aktuali problema. Automobiliu srautams vis labiau didejant, dideja ir ju keliamas triukšmas, ypač triukšmingi yra sunkvežimiai ir motociklai. Triukšmo tyrimai atlikti Panevežio pietineje dalyje prie pagrindiniu gatviu. Matavimai vyko skirtingu paros laiku: diena 6–18 val., vakare 18–22 val. ir nakti 22–6 valandomis. Šioje miesto dalyje pagrindine triukšmo priežastis – automobiliai. Triukšmo lygis, išmatuotas vietose, kuriose dažniausiai viršijamas, lyginamas su leidžiamosiomis normomis. Atlikta triukšmo lygiu ir transporto srautu analize. Iš duomenu matyti, kad leidžiamasis triukšmo lygis diena viršytas 65 %, vakare 88 %, o nakti – 71 % atliktu matavimu. Ekvivalentinis triukšmo lygis viršytas iki 14 dBA, o maksimalusis leidžiamasis – iki 17 dB. Labiausiai triukšmo lygis viršijamas prie gatviu, kuriose pravažiuoja daugiausia automobiliu. Резюме Шум является актуальной проблемой не только в Литве, но и во всем мире. С увеличением автомобильных потоков неизбежно увеличивается и вызываемый ими (особенно грузовиками и мотоциклами) шум. Исследования шума проводились в южной части города Паневежиса, вблизи основных улиц в разное время суток: днем с 6 до 18 часов, вечером с 18 до 22 часов и ночью с 22 до 6 часов утра. В этой части города основным источником шума являются автомобили. Измеренные уровни шума были сравнены с допустимыми уровнями для мест, в которых он чаще всего превышен. Произведен анализ уровней шума и транспортных потоков. Из данных измерений видно, что допустимый уровень шума в дневное время был превышен в 65%, вечером – в 88%, а ночью – в 71% проведенных измерений. Эквивалентный уровень шума превышен до 14 дБа, а максимально допустимый – до 17 дБа. Уровни шума особенно увеличены вблизи улиц, по которым проезжает больше всего автомобилей. First Publish Online: 10 Feb 2011 Reikšminiai žodžiai: transporto triukšmas, triukšmas gyvenamojoje aplinkoje, leidţiamasis triukšmo lygis. Ключевые слова: транспортный шум, шум в жилой среде, допустимый уровень шума

The hidden pharmaceutical advertising in Lithuanian's periodical press

Žiniasklaida tapo verslu, kuris didele dalimi priklauso nuo reklamos, nes didžiausios finansinės įplaukos gaunamos būtent iš jos. Globalizacija, komercialėjimas, konvergencija – visų šių procesų dėka reklama Lietuvos žiniasklaidoje įgavo dar didesnį pagreitį. Nuolatinis žiniasklaidos bendrovių varžymasis dėl išlikimo rinkoje, etiškumo stoka bei tiesioginė priklausomybė nuo reklamos, kaip nuo pagrindinio pajamų šaltinio lėmė ne tik reklamos reiškinio išplitimą, bet ir jos transformacijų pasirodymą – paslėptą reklamą. Paslėpta reklama – tai reklaminio pobūdžio informacija apie tam tikrą gamintoją, produktą ar paslaugą, kuri nėra pažymima kaip reklama. Šios reklamos apraiškos žiniasklaidoje n��ra lengvai aptinkamos ir atpažįstamos, nes jose reklaminė informacija dažnai pateikiama kaip redakcijos ar žurnalistų nepriklausoma nuomonė. Farmacijos sektorius – tai vienas iš stambiausių reklamos užsakovų žiniasklaidoje. Kompanijų susikūrimas bei naujų vaistinių produktų pasirodymas rinkoje skatina didelę konkurenciją. Siekiant padidinti pardavimus ir laimėti konkurencinėje kovoje, farmacijos bendrovės nuolat investuoja į reklamą, dažnai panaudodamos ir draudžiamas reklamos formas žiniasklaidoje. Todėl šio darbo tikslas yra išnagrinėti paslėptos farmacijos reklamos ypatumus ir jų raišką Lietuvos periodinėje spaudoje. Spauda – tai anksčiausiai atsiradęs ir labiausiai išsivystęs žiniasklaidos sektorius. Laikraščiai, žurnalai, brošiūros – tai populiariausi leidiniai, kuriuos farmacijos kompanijos panaudoja reklaminei informacijai skleisti, todėl paslėptos farmacijos reklamos apraiškų buvo ieškoma šiame žiniasklaidos segmente. Žurnalų turinio analizė parodė augančio paslėptos farmacijos reklamos vartojimo tendenciją. Žurnalai, skirtingai nuo laikraščių, tampa vis patrauklesne terpe nepažymėtiems reklaminiams straipsniams talpinti. Tą sąlygoja šio spaudos segmento didesnė išliekamoji vertė, tiesioginis tikslinių auditorijų pasiekiamumas bei jame pateiktos informacijos patrauklumas. Be to, be dalis aptiktų draudžiamos farmacijos reklamos atvejų išsiskyrė nauja formos transformacija, t.y. kai reklama pateikiama kaip žurnalo redakcijos nuomonė. Tuo tarpu laikraščiuose buvo pastebima nepažymėtos vaistų reklamos apraiškų mažėjimo tendencija. Tai rodo, jog dienraščiai, dažniausiai skirti pakankamai didelei visuomenės daliai, vis rečiau patenka į farmacijos kompanijų akiratį.The media became a business, which depends on advertisment more and more, as the greatest financial income is given out of it. Because of such processes as globalisation, commercialism and convergence, the advertisement is spreading rapidly in Lithuania. The continuous competition between the organisations of the media for the survival in the market, the shortage of ethics and the direct dependence from advertisement, as from the main source of income, made the advertisement to spread and showed the hidden types of advertisement. The hidden advertisement is a type of advertisement information about the manufacturer, the product and the service itself. It is necessary to mention, that all these things are not marked as advertisement. It is hard to find and recognize such types of advertisement in the media, as the information of the advertisement is often given, as the independent opinion of editorials and journalists. The division of pharmaceutics is one of the greatest customers of the advertisement in the media. The foundation of companies and the appearance of new medical products in market encourage a great competition. These companies of pharmaceutics continually make investments in the advertisement, as they want to increase the sales and to win the competition. It is often used the forbidden forms of advertisement in the media. The aim of this paper is to analyse the peculiarities of the hidden types of advertisement and its expression in the periodical press in Lithuania. The press is described as the earliest and the most developed sector of the media. The most popular publications are newspapers, magazines and brochures, which are used to spread the information of advertisement by the companies of pharmaceutics. This is the reason, why everybody was searching the hidden advertisement in this section. The analysis of the content of magazines showed the tendency of the risen use of hidden advertisement. Magazines, unlike newspapers, are becoming more and more attractive environment for unmarked articles. This thing is because of the great remaining value of this section, the direct availability of the audience and the fascination of the given information in it. By the way, the new form of transformation is found because of hidden advertisement. This means, that the advertisement is produced according to the opinion of the editorial of the magazine. The declining tendency of unmarked medical products was found in newspapers. This thing shows, that newspapers are rarely read by the companies of pharmaceutics. They are designed for the great part of the society.Vytauto Didžiojo universiteta

The numerical simulation of curved flue flow in multi-channel spiral cyclone

Det interne eksil – Om samtidens amerikanske fængse

The possibilities of using sapropel for briquette production

This article describes the possibilities of using renewable energy fuel sources for the purpose of producing thermal energy. One of the options (alternatives) is to use sapropel (lake sediment biomass) not only as a fertilizer, feed additive, binder etc. but also as an energy fuel. One of the first steps to material extraction and preparation is fuel briquette (direct extraction of useful heat) production, technology and methodology. The article compares the author’s findings with analytical and experimental results obtained by other scientists. Article in English. Sapropelio panaudojimo galimybės briketams gaminti Santrauka. Straipsnyje pateiktos atsinaujinančių energijos kuro šaltinių panaudojimo galimybės šilumos energijai gaminti. Viena iš galimybių (alternatyvų) yra sapropelį (ežerų dugno nuosėdų biomasę) naudoti ne tik kaip trąšą, pašarų priedą, rišiklį ir pan., bet ir kaip energetinį elementą. Straipsnyje pateikta: žaliavos paruošimas kuro briketams gaminti, paruoštos biomasės briketavimo technologija, pagamintų sapropelio su priedais briketų deginimas (tiesiogiai naudojamų šilumai išgauti), briketus deginant išsiskiriančių teršalų koncentracijos. Gauti rezultatai lyginami su kitų autorių analitiniais ir eksperimentiniais rezultatais. Raktiniai žodžiai: sapropelis, briketai, briketų gamyba, CO, NOX

Testing on noise level prevailing at motor vehicle parking lots and numeral simulation of its dispersion

In Vilnius and in other bigger towns the noise generated by mobile sources accounts for up to 90 % of the total noise level in a town. A high noise level is detected at motor vehicle parking lots. To measure this noise level, testing was carried out at guarded parking lots which were divided into certain types. One lot of each type was chosen for testing. The number of measuring spots was conditioned by the size of a lot. The data obtained during testing reveal that the highest noise level is generated not at a parking lot but on a nearby street. Such conclusions are proved by the results of testing carried out at a parking lot on È. Sugihara street. Although this lot parks over 100 vehicles, the equivalent noise level is 47 dBA. Basing on the testing data, the numeral simulation of the noise dispersion in areas in the vicinity of parking lots has been run with the help of the numeral simulation software IMMI. Triukšmo automobilių stovėjimo aikštelės tyrimai ir jo sklidimo skaitinis modeliavimas Santrauka Vilniuje ir kituose didesniuose miestuose mobiliųjų šaltinių skleidžiamas triukšmas sudaro iki 90 % viso miesto triukšmo lygio. Aukštas triukšmo lygis esti automobilių stovėjimo aikštelėse. Siekiant jį įvertinti atlikti tyrimai. Saugomas automobilių stovėjimo aikšteles suskirsčius pagal pobūdį, pasirinkta po vieną skirtingo tipo aikštelę. Matavimo taškų skaičių lėmė aikštelės dydis. Gauti tyrimų duomenys rodo, kad didžiausias triukšmas sklinda ne iš pačios automobilių stovėjimo aikštelės, o iš šalia esančios gatvės. Tokią išvadą įrodo triukšmo lygio automobilių stovėjimo aikštelėje Č. Sugiharos gatvėje tyrimo rezultatai. Nors šioje aikštelėje saugoma per 100 automobilių, tačiau nustatyta, kad joje ekvivalentusis triukšmo lygis ‐ 47 dBA. Remiantis tyrimų duomenimis, atliktas triukšmo sklidimo į šalia automobilių stovėjimo aikštelių esančią teritoriją skaitinis modeliavimas. Modeliavimui naudojama skaitinio modeliavimo programa IMMI. Reikšminiai žodžiai: transportas, triukšmas, automobilių aikštelės, modeliavimas, skaitinis First Published Online: 14 Oct 201

Research and Modelling of Noise of the Central Part of Panevėžys City

Panevėžys city is divided into three parts – Southern, Northern and Central. Noise level in the central part of Panevėžys city is discussed in this paper. Noise level at streets is measured at different time of the day. Noise level modelling is carried out in the central part of Panevėžys. Modelling results are compared to measured ones. The inadequacy of measured and modelled results d being up to 10%, assumption is made that the modelled and the measured results correlate, and noise level in residential areas as well as at streets is analyzed according to the results of modelling in the day – time and by night. The main sources of noise and the highest noise level zones where the inhabitants are affected by the increased noise level most are revealed

Distribution of heavy metals in the lake Talkša (Lithuania) sapropel and possibilities of practical use

This article presents the results of investigations addressing the accumulation of heavy metals in different layers of the Lake Talkša, Lithuania. For the sampling from the ice of intact structure of the sediment the turf borer was used. Concentrations of these heavy metals in sapropel layers were determined in the extracts of sapropel. After the preparation of samples, the concentration of Pb, Ni, Cr, Zn and Cu were measured in the laboratory by means of atomic absorption spectrometry. The results showed that sapropel taken from the northern shores of Talkša Lake is stratified according to LAND 20-2005 and should be classified as sludge of I and II category. Based on the concentration of Pb, Ni, Zn, Cu, sapropel should be classified as I category. However, according to the maximum concentrations of Cr (257.5 mg/kg) detected in the upper horizon of the sludge, sapropel should be iconsidered as of IInd category. Within other horizons, sapropel is not contaminated with heavy metals, while metal concentrations could be treated as trace elements. Sapropel recovered from this part of the lake could be exploited by excavation and widely used for various economic needs

The Distribution of Heavy Metals in Sediments in the Lake Talksa of Lithuania

The intensification and development of industrial processes has harmful effects of human activities on nature and entire environment. Having performed the assessment of contamination of environmental components, especially geological environment (soil, sediments from bottoms of water bodies, including sapropel), it is possible to make a quantitative evaluation of the scope of anthropogenic influence and often the hazardousness of such influence on biota and people. Heavy metals enter water reservoirs and, at the same time, sapropel from atmosphere and with surface-water and underwater. Part of heavy metals, which are found in deeper deposits of sapropel, have built up naturally in the course of complex hydro-chemical and hydro-biological processes, which formed over thousands of years when the atmosphere and waters were not as polluted as they are today. A large number of sediment samples representing most of the active accumulation areas in Lake Talksa of Lithuania were studied for total copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), lead (Pb) and manganese (Mn). Quantities of most heavy metals in sapropel decline noticeably with depth, if compared to the surface layer. The lowest concentrations of heavy metals are discovered at a depth of 200–250 cm. The trend of declining concentration of heavy metals in sapropel layers with depth is obvious throughout the section