186 research outputs found

    Gateway-pathway heritage and urban growth zagreb case study

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    This paper is a part of on-going research into the typological definition of 'urban gateway-pathways'. This term refers to routes used to connect peripheral settlements to the urban core of contemporary cities. The typology was developed with reference to a sample of 18 Central European cities that were formerly provincial capital cities of the Austro-Hungarian monarchy. This paper provides the first authoritative syntactical description of the city of Zagreb and reports on initial syntactical analysis of its historic pathway typology using the transect method established by Hi II ier (1999). The results from the transect analysis are then used to provide more refined typological descriptions of the gateway-pathways and their historical transformations, and to frame a future phase of research using segment analysis

    Aerosol synthesis of phosphor based onĀ Eu3+ activated gadolinium oxide matrices

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    Poster presented at the Seventh International Conference on Ceramic Processing Science, Inuyama, Japan, May 15-18, 200

    Analysis of the vehicle exhaust system corrosion and its effect on the ECO-test result

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    This paper deals with analysis of the vehicle exhaust system quality and its influence on the results of measuring exhaust emissions of the Otto and Diesel motor vehicles. Results of eco-tests obtained from correct and faulty vehicle exhaust systems were compared to conclude that damages caused by corrosion had significant influence on the pass rate of vehicles at eco-test. Referring to vehicles with the Otto engine, damages in the exhaust system increase the oxygen level, which results in the increased Ī» factor and in failure at the eco-test. On the contrary, vehicles with the damaged Diesel engine exhaust system allow the gas to leak through the damage, so the measurement of blackening is lower, i.e. the eco-test result is better than that of the exhaust system without damage

    Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

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    Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K) were determined by the broadening of the recorded spectral profiles as a function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno

    Procena ekoloŔkog rizika u funkciji zaŔtite životne sredine

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    This paper proposes an appropriate methodology for ecological risk assessment. The methodology has been applied in the region of Boka Kotorska Bay (Bay), Montenegro. The emphasis of the research is on the analysis of the impact of various stressors on the ecological components of Bay. The consequences of that impact can be seen in an increased level of eutrophication of water environment, mostly through the influence of nitrogen and its compounds. The actual research at/about the region of Boka Kotorska Bay was performed in the period of 2008. The study emphasized the importance of the acquisition, processing and analysis of various ecologically related data for more efficient monitoring and management of the environment. The suggested methodology of the ecological risk assessment is, therefore, a remarkable scientific and expert contribution in the area of environmental protection in our country and in general.U radu je predstavljena primena metodologije procene ekoloÅ”kog rizika. Metodologija je primenjena na primeru Bokokotorskog zaliva (Zaliv). Istraživanjem je razmatrana procena uticaja većeg broja stresora na ekoloÅ”ke komponente Zaliva. Posledice ovih uticaja ispoljene su kroz povećan stepen eutrofikacije vodene sredine i dovode se u vezu sa koncentracijom azotnih jedinjenja (nitrata i nitrita) Konkretna merenja vrÅ”ena su u 2008. godini. Istraživanjem je posebno ukazano na značaj razvoja sistema prikupljanja i obrade ekoloÅ”kih i drugih informacija radi efikasnijeg upravljanja životnom sredinom datog prostora. Primenjena metodologija procene ekoloÅ”kog rizika trebalo bi da u naučnom i stručnom pogledu predstavlja doprinos u oblasti zaÅ”tite životne sredine,kako kod nas, tako i u svetu

    Playing with fire: Exploring ceramic pyrotechnology in the Late Neolithic Balkans through an archaeometric and experimental approach

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    Addressing ceramic pyrotechnology plays a key role in understanding a wide range of cultural and social behaviours associated to pottery production. Firing is the process which transforms clay into ceramic, which is one of the most frequently preserved materials in the majority of Neolithic and later archaeological sites. Though firing temperatures and the functions of various pyrotechnological installations have been extensively investigated in archaeology, both have often been addressed separately. Most of our knowledge on firing structures and procedures in the Neolithic are still largely based on ethnoarchaeological evidence. To move forward, we need to consider all aspects involved in ancient pyrotechnology, together with use of additional investigative tools. This study aims to address Neolithic pottery firing from a diverse perspective that merges archaeometric analyses and experimental archaeology. To demonstrate the potential of this approach, we combined an archaeometric case study of pottery from the late Neolithic (5200ā€“4800 BCE) from the site of GradiÅ”te-IđjoÅ” (Serbia) with experimental pit firings, likely one of the mostly frequently employed firing techniques used in prehistoric periods. Scientific analyses include X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), and ceramic petrography. These methods were run on both archaeological materials and experimental reproductions. Additionally, a detailed program of firing temperature monitoring, integrated observations on atmospheric conditions, soaking time, and duration were recorded to contribute to the study. The experiments enabled us to collect results useful for our understanding of the pyrotechnological knowledge of Neolithic potters from a technological and social point of view. In addition, they demonstrated the potential of a dedicated methodological framework for studying pottery firing that can be applied to other chronological and cultural contexts

    Green Extraction Strategy Using Bio-Based Aqueous Biphasic Systems for Polyphenol Valorization from Grape By-Product

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    Polyphenols are natural compounds with enhanced antioxidant properties. They are present in relatively high concentrations in fruit/vegetable by-products. Therefore, there is a need for the development of efficient and cost-effective methods for the separation and purification of these valuable compounds. Traditional extraction with organic solvents needs to be switched to novel methods that are more efficient, with reduced extraction times and low consumption of organic solvents. Aiming at developing sustainable processes for the separation and purification of phenolic compounds, we used three model compounds, namely resveratrol, quercetin, and gallic acid, to investigate ionic liquid-based aqueous biphasic systems (IL-ABSs) formed by choliniumbased IL in combination with polypropylene glycol with a molecular mass of 400 g/mol (PPG400). The ABS composition in the two-phase region was selected according to a previously determined phase diagram. Extraction studies indicated the preferential partition of resveratrol and quercetin toward the hydrophobic PPG-rich phase that is mainly dominated by its hydrophobic nature and the strong salting-out effect of ILs. On the other hand, due to its considerably hydrophilic nature, gallic acid preferentially migrates toward the IL phase. The achieved results from grape stem extract demonstrated high extraction efficiencies of cholinium dihydrogen phosphate (~99% for resveratrol for the PPG phase and 78% for gallic acid for the IL phase), with considerable selectivity, demonstrating promising outcomes for potential applications
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