Акустички судови као израз музичке традиција српске средњовековне архитектуре

Archaeoacoustics is a multidisciplinary field of research focused on the history of the relatedness of the field of sound and architecture. The architectural history of Europe, from Antiquity to the modern period, is abundant in the findings of vessels, which are considered to have an acoustic purpose. This paper addresses these acoustic vessels embedded in the massive walls of sacred architecture in medieval Serbia (15 churches). We considered the wide context of current archaeoacoustic research, in order to argue that this practice can be regarded as an expression of a certain medieval musical tradition.Истраживање звука у архитектури завређује посебно место у студијама културног наслеђа, захтевајући притом мултидисциплинаран приступ. Кроз градитељску историју Европе, од античког до савременог доба, коришћени су одређени судови, за које се сматра да су имали акустичку намену. Овај рад представља резултате истраживања акустичких судова уграђених у камене зидове сакралне архитектуре средњовековне Србије и одговара на питање да ли се ова пракса може сматрати изразом извесне музичке традиције. У првом делу рада сагледан је шири контекст археоакустичких истраживања средњовековне Европе. Представљени су кључни изводи из Витрувијевог дела Десет књига о архитектури – најстаријег документа са описом акустичких судовa. Затим, дат je кратак преглед релевантних археоакустичких студија и извода који илуструју акустичке намере средњовековних градитеља. У другом делу рада представљени су налази акустичких судова из средњовековне Србије – историјски оквир истраживања, преглед истраживања ове теме код нас, попис налаза (из укупно 15 цркава) и досад спроведене акустичке студије. У трећем делу рада дискутованa су физичка својства акустичких судова, њихов распоред, позиција и оријентација у зиду, акустичке одлике, итд. Показано је да постоји одређени ниво правилности у постављању судова, као и у њиховим физичким својствима. Пронађени су у свим осталим градитељским периодима осим у византијској групи споменика (доминантно у Рашкој, XIIXIII век). Поред тога што је показано да се пракса узиђивања акустичких судова може сматрати извесним изразом музичке традиције сакралне архитектуре средњовековне Србије, такође је указано на неопходност даљих истраживања – акустичких мерења in situ, испитивања рачунарских модела или лабораторијских мерења судова. Поврх свега, овај рад омогућио је да се налази акустичких судова из српске средњовековне архитектуре позиционирају на археоакустичкој мапи Европе и тако допринесу разумевању односа звука и архитектуре кроз историју градитељства.The paper is a result of research on the project Society, spiritual and material culture and communication on the Balkans in prehistory and early history of Balkans (No. 177012) and the project Theory and practice of science in society: multidisciplinary, educational and intergenerational perspectives (No. 179048). The Ministry of Education, Science and Technological Development of the Republic of Serbia finances both projects. We are grateful for the help that we received from Jean-Christophe Valière from the University of Poitiers and Emilija Pejović from the Republic Institute for Protection of Cultural Monuments, Belgrade

Karakterizacija specifičnih izvora buke u urbanoj sredini i metode zaštite

The first goal of this dissertation is the characterisation of outdoor noise emission of specific low–frequency noise sources: floating river clubs and moored ships. Their specificity is reflected in the fact that they are characterised by large dimensions, but also that they are not easily approachable. Most available measurement methods for determination of sound power levels define a large number of measurement positions around the sound source. Nevertheless, a relatively simple measurement method is preferred in practical applications, particularly if sound sources are located in such unfavourable environments. For this reason, the implementation of different existing measurement methods has been investigated in this dissertation in order to identify the most optimal one under the given circumstances. Additionally, indoor sound level spectra for different types of entertainment premises, including floating river clubs, have been investigated and a modified spectrum adaptation term for a single–number rating of sound insulation against the low–frequency entertainment noise has been proposed. The second goal of this dissertation is the investigation of capabilities and limitations of in situ test methods for measuring acoustic properties of noise barriers. For this purpose, a dedicated measurement system consisting of a microphone array, signal processing device and signal generator, has been designed and applied to two types of noise barriers: a conventional sound absorbing barrier and a prototype of sound absorbing sonic crystal. While the application of the in situ methods to conventional noise barriers has been thoroughly investigated in the literature, there has been very limited data about their application to periodic structures, such as sonic crystals.Prvi cilj ove disertacije je karakterizacija spoljne buke emitovane od strane specifičnih izvora niskofrekventne buke: plutajućih rečnih splavova i usidrenih brodova. Njihova specifičnost se ogleda u činjenici da se karakterišu velikim dimenzijama, ali i da im nije lako pristupiti. Većina dostupnih mernih metoda za određivanje zvučnih snaga definišu veliki broj mernih pozicija oko zvučnog izvora. Ipak, u praktičnim aplikacijama je poželjna relativno jednostavna merna metoda, posebno ukoliko se izvori buke nalaze u tako nepovoljnim okruženjima. Iz tog razloga, u disertaciji je istražena primena različitih postojećih mernih metoda kako bi se identifikovala najoptimalnija u datim okolnostima. Dodatno, istraženi su spektri zvučnih nivoa u zatvorenom za različite tipove objekata zabave, uključujući i rečne splavove, i predložen je modifikovani korekcioni faktor za merodavnu ocenu zvučne izolacije u slučaju niskofrekventne buke zabave. Drugi cilj ove disertacije je istraživanje mogućnosti i ograničenja in situ metoda za merenje akustičkih svojstava zvučnih barijera. U tu svrhu, dizajniran je namenski merni sistem koji se sastoji od mikrofonskog niza, uređaja za obradu signala i signal generatora, i primenjen na dva tipa zvučnih barijera: konvencionalnu apsorbujuću zvučnu barijeru i prototip apsorbujućeg zvučnog soničnog kristala (eng. sonic crystals). Iako je primena in situ metoda na konvencionalnim barijerama detaljno istražena u literaturi, postoji vrlo ograničen broj podataka o njihovoj primeni na periodičnim strukturama, kao što su sonični kristali

Application of mineral processing methods in recycling the waste printed circuit board

Recycling of the waste printed circuit boards (PCBs) is necessary from both an economic and an environmental point of view. Large amounts of waste contain significant amounts of valuable metals used as the secondary source. The PCBs can be viewed as a complicated mineral raw material on which mineral processing procedures can be applied. This work presents the mineral processing procedures used in the certain stages of recycling waste printed circuit boards

Detection and enhancement of latent fingerprints using dextran-based biopolymer powders obtained from anthocyanin solution

Dextran is extensively exploited in medicine and pharmacy, but, currently no studies using this biopolymer as a powder system for enhancement of latent fingerprints were published. In this paper four different formulations of dextran-based biopolymer powders, obtained by simple precipitation of dextran within anthocyanin solution, were synthetized and characterized in order to determine potential of these biopowders in forensic application. Since detrimental effect on humans is often present while routinely employing commercial dusting methods, the main advantage of prepared dextran-based biopowders are their non-toxic properties, contributing to the safer/healthier operating conditions. The interactions between components of the systems were confirmed by FT-IR analysis. Optical microscopy was used to determine the size of the prepared biopowders, while simultaneously confirmed the interaction between powders and the sweat/lipid residues present in the latent trace. The results demonstrated the potential of novel dextran-based biopowders to supplement routinely employed physical systems in visualizing latent fingerprints

Agricultural enterprises and economic growth: A regional analysis in the Republic of Serbia

Since agriculture is the highly important economic activity in the Republic of Serbia, it is necessary to create an environment in which competitive agricultural enterprises will develop. However, regions in the Republic of Serbia considerably differ regarding the intensity of agricultural activity. This paper examines the impact of agricultural enterprises on the region's contribution to the gross domestic product (GDP) of the country in the period between 2010 and 2018. Activity of agricultural enterprises was observed using number of agricultural enterprises, number of employees in them, their turnover and gross value added. Random-Effects GLS regression showed that regions with higher agricultural activity contribute to the lesser extent to the GDP of the country. Research results are robust to changing sampling period and lagging independent variables. In this regard, several proposals have been recommended.Publishe

Organic soya bean production in Serbia

In Serbia during 2021, organic crop production was performed on the area of 23,527 ha. The area of 2121.6 ha on which industrial crops were grown ranked fourth comparing to the total arable area sown with organic crops. Soya bean is one of the most important legumes, primarily because of the exceptional chemical composition of the grain (40% proteins and 20% oil). This manuscript reveals the analyses and graphic presentation of the area trends and the regional distribution of organic soya bean production in Serbia in the 2011-2021 period. The desk research was applied. Organic farming of soya bean is carried out on the area of 481 ha, right behind the leading sunflower (1,165 ha). In the region of Vojvodina, there are the largest areas on which organic growth of soya bean is performed. However, the organic soya bean production in Serbia is still insignificant, despite favourable agroecological conditions and market demands

Commercial P-Channel Power VDMOSFET as X-ray Dosimeter

The possibility of using commercial p-channel power vertical double-diffused metal-oxide-semiconductor field-effect transistors (VDMOSFETs) as X-ray sensors is investigated in this case study. In this aspect, the dependence of sensitivity on both the gate voltage and the mean energy for three X-ray beams is examined. The eight gate voltages from 0 to 21 V are applied, and the dependence of the sensitivity on the gate voltage is well fitted using the proposed equation. Regarding X-ray energy, the sensitivity first increases and then decreases as a consequence of the behavior of the mass energy-absorption coefficients and is the largest for RQR8 beam. As the mass energy-absorption coefficients of SiO2 are not found in the literature, the mass energy-absorption coefficients of silicon are used. The behavior of irradiated transistors during annealing at room temperature without gate polarization is also considered

BEAMDB and MOLD—Databases at the Serbian Virtual Observatory for Collisional and Radiative Processes

In this contribution we present a progress report on two atomic and molecular databases, BEAMDB and MolD, which are web services at the Serbian virtual observatory (SerVO) and nodes within the Virtual Atomic and Molecular Data Center (VAMDC). The Belgrade Electron/Atom (Molecule) DataBase (BEAMDB) provides collisional data for electron interactions with atoms and molecules. The Photodissociation (MolD) database contains photo-dissociation cross sections for individual rovibrational states of diatomic molecular ions and rate coefficients for the chemi-ionisation/recombination processes. We also present a progress report on the major upgrade of these databases and plans for the future. As an example of how the data from the BEAMDB may be used, a review of electron scattering from methane is described

Antimicrobial potency of Ru(II) arene based pyridil complexes

Discover a new class of ruthenium-based complexes that were investigated as potential antimicrobial agents: dinuclear polypyridil ruthenium(II) complexes exhibited excellent growth inhibition, and Ru(II) arene complexes with acetyl pyridine ligands exhibited moderate antimicrobial activity in the panel of bacteria1. Here we have synthesized 14 new Ru(II) arene complexes with pyridine-based ligands and examined their antimicrobial potency, trying to correlate their structure and biological activity. Reported complexes were obtained in a reaction of [Ru(η6-benzene)Cl(μ-Cl)]2 or [Ru(η6-toluene)Cl(μ-Cl)]2 with halogen derivatives of picolinic acid or pyridine dicarboxylic acids in a 1:2 molar ratio in ethanol. The complexes were soluble in DMSO and water. Their structural characterization included IR and NMR spectroscopy and MS spectrometry, and purity was confirmed by elemental analysis. In this report, we demonstrate the activities of these novel compounds against six typical gram-negative and two gram-positive bacteria. A micro-well dilution assay was used to determine the minimum inhibitory concentration (MIC), and minimum bactericidal concentration. Streptomycin and chloramphenicol, commercial antibiotics, were used as a positive control. The best activity of all tested bacteria was observed against E. coli, with a MIC value of 1.25 mg/mL, for C3, C6, and C10 complexes. Also, all synthesized complexes showed the same activity against C. albicans

Ru(II) arenski kompleksi sa piridinskim ligandima: sinteza i antimikrobna aktivnost

Metal-based compounds are rarely good antimicrobial compounds. Here we report synthesis, chemical characterization and antimicrobial potency of fourteen Ru(II) arene complexes with pyridine-based ligands. The structures and purity of synthesized compounds were confirmed using 1H and 13C NMR spectroscopy, IR spectroscopy, MS, and EA. A micro-well dilution assay was used to determine the minimum inhibitory concentration (MIC), and minimum bactericidal concentration. of evaluated compounds. Streptomycin and chloramphenicol were used as a positive control. The best activity of all tested bacteria was observed against E. coli, with a MIC value of 1.25 mg/mL, for complexes with 2,4- i 2,5-pyridinedicarboxylic ligands. Also, all synthesized complexes showed the same activity against C. Albicans.Kompleksi metala retko se koriste kao potencijalni antimikrobni agensi. U ovom radu smo prikazali sintezu, hemijsku karakterizaciju i antimikrobnu aktivnost 14 arenskih Ru(II) kompleksa sa piridinskim ligandima. Strukturu i čistoću dobijenih jedinjenja potvrdili smo koristeći 1H, 13C NMR i IC spektroskopiju, MS i EA. Mikrodilucioni esej je korišćen za određivanje minimalne inhibitorne koncentracije (MIC) i minimalne baktericidne koncentracije sintetisanih jedinjenja. Streptomicin i hloramfenikol su korišćeni kao standard. Najbolja aktivnost prema ispitivanim sojevima bakterija zapažena je na soju E. coli, sa MIC vrednošću 1,25 mg/mL, kompleksa sa 2,4- i 2,5-piridindikarboksilnim ligandima. Svi sintetisani kompleksi pokazali su podjednako dobru aktivnost prema C. Albicans