Agricultural production of the Roman provincies in the territory of Serbia : from the 1st to the first half of 5th century

Proučavanja u ovom radu su usmerena na istraživanja različitih elemenata koji se odnose na poljoprivrednu proizvodnju i njen razvoj, kao i promene u njenoj strukturi koje su nastale uspostavljanjem rimske vlasti na teritoriji današnje Srbije u periodu od I do početka V veka. Prema raspoloživim arheološkim podacima, ali i pisanim izvorima, delimično su sagledani uslovi koji su određivali okvire ekonomske aktivnosti stanovništva tokom rimskog perioda i u sklopu toga agrikulture kao fundamentalne delatnosti. Naročita pažnja je posvećena istraživanju tipično rimskih formi poljoprivrednih imanja organizovanim kao vile rustike (villae rusticae) što predstavlja vrlo kompleksan zadatak, budući da uključuje osetljive tipološke i hronološke analize samih građevina kroz arhitektonske forme, koje ponegde uključuju i postojanje žitnica i drugih ekonomskih objekata u sklopu poljoprivrednog imanja. Tokom istraživanja uzimani su u obzir i podaci koje možemo dobiti iz prirodnog okruženja, kao što su: osobine reljefa, pedeološki i hidrološki faktori, klimatske karakteristike itd. Cilj sprovedenog istraživanja bio je da se pruži detaljnije tumačenje arheološke građe koje daje istorijski odgovor na pitanje celokupne poljoprivredne aktivnosti u postavljenim geografskim okvirima sa pokušajem teritorijalne, tipološke i hronološke diferencijacije. Centar pažnje usmeren je na izučavanje forme i organizacije poljoprivrednih imanja, budući da su se zbog različitih socijalno-ekonomskih odnosa, ali i geografskih i klimatskih uslova nužno morale razlikovati od onih u Italiji, ali i drugim provincijama Carstva. Organizacione promene u načinu obrade i kultivisanja zemljišta, uz primenu novog tehnički savršenijeg oruđa od onog korišćenog u predrimskom periodu, novi vidovi uzgoja domaćih životinja, neminovno su uticali na ekonomsko-socijalno raslojavanje stanovništva i proces romanizacije koji je bio intenzivniji u ravničarskim regionima, za razliku od brdsko-planisnkih oblasti gde se usled manje pogodnih prirodnih uslova i izolovanosti prostora uglavnom zadržao tradicionalni način privređivanja. Sagledavši sve prikupljene podatke o proizvodnim jedinicama u poljoprivredi, sredstvima za proizvodnju, transport i distribuciji namirnica, flori i fauni, opšti je zaključak da je stanovništvo panonsko-balkanskog prostora bilo pretežno poljoprivredno u rimskom periodu. KLJUČNE REČI: poljoprivredna proizvodnja, vici, villae rusticae, horrea, snabdevanje i transport, poljoprivredno oruđe, provincije Gornja Mezija, Donja Panonija, istočna Dalmacija, rimski period.The studies in this paper is focused on the investigation of various elements relating to agricultural production and its development, as well as changes in its structure arising establishment of Roman rule in the territory of Serbia in the period from the first to the beginning of the fifth century. According to archaeological evidence, but also written sources, in part conditions were perceived that were determined frames of economic activity of the population during the Roman period and within that agriculture as a fundamental activity. Special attention has been devoted to the study of typical Roman forms of farms organized as villae rusticae which is a very complex task, since it involves sensitive typological and chronological analysis of the buildings themselves through architectural forms, that sometimes involve the existence of granaries and other economic structures in the farm. During the study, it was taken into account data that we get from the natural environment, such as: terrain features, pedological and hydrological factors, climatic characteristics, etc. The aim of the research was to provide a more detailed interpretation of archaeological material that provides historical answer to the question of the entire set of agricultural activities in geographical terms in attempt territorial, chronological and typological differentiation. Center of attention is focused on the study of form and organization of farms, as they are due to various socio-economic relations, but also the geographic and climatic conditions must necessarily differ from those in Italy, but also in other provinces of the Empire. Organizational changes in release and cultivation of land, with the application of a new technically superior tools than that used in the pre-Roman period, new forms of livestock farming, inevitably affected the economic and social stratification of the population and the process of romanization, which was the strongest in the lowland regions, in contrast to highlands areas where due to less favorable natural conditions and isolation of space generally kept the traditional way of economic activity. Analyzed all the data on the production units in agriculture, means of production, transport and distribution of food, flora and fauna, the general conclusion is that the population of the Pannonian-Balkan area was predominantly agricultural in the Roman period

Optimization and kinetic modeling of waste lard methanolysis in a continuous reciprocating plate reactor

Continuous biodiesel production from a waste pig-roasting lard, methanol and KOH was carried out in a reciprocating plate reactor (RPR) using a factorial design containing three process factors, namely methanol/lard molar ratio, catalyst loading, and normalized height of the reactor. The main goals were to optimize the influential process factors with respect to biodiesel purity using the response surface methodology and to model the kinetics of the transesterification reaction in order to describe the change of triacylglycerols (TAG) and fatty acid methyl esters (FAME) concentrations along the RPR height. The first-order rate law was proved for both the reaction and the mass transfer. The model of the changing reaction mechanism and mass transfer of TAG was also applicable. Both kinetic models agreed with the experimental concentrations of TAG and FAME determined along the RPR height

Biodiesel production by methanolysis of waste lard from piglet roasting over quicklime

Waste lard from piglet roasting and quicklime (basically CaO) as a priceless fatty feedstock and a cheap solid catalyst, respectively were tested for the biodiesel production by methanolysis in a batch stirred reactor at moderate reaction temperatures (40-60 degrees C) for the kinetic study. For comparison, unheated and heated pork lards, as well as pure CaO, were also included in this study. The mass transfer limitation was observed in the initial period of all methanolysis reactions. The kinetic model combining the changing-and first-order reaction rate laws with respect to triacylglycerols and fatty acid methyl esters (FAMEs), respectively was verified for all three lardy feedstocks and both catalysts. The catalytic activity of quicklime was the same as that of pure CaO. The activation energy was demonstrated to be independent of the feedstock and the catalyst (59.1 +/- 0.6 kJ/mol) but the waste lard reacted faster than the unheated and heated pork lards. At the methanol-to-lard molar ratio of 6:1, the catalyst amount of 5% (based on the lard weight) and the reaction temperature of 60 degrees C, a high FAME concentration in the final ester products (97.5%) within 60 min were achieved with the waste lard and quicklime in two consecutive batches. The same kinetic model was applicable in a continuous packed-bed tubular reactor filled with quicklime bits (2.0-3.15 mm) at the methanol-to-waste lard molar ratio of 6:1, the reaction temperature of 60 degrees C and the residence time of 1 h. Under these conditions, the biodiesel yield was 97.6%, while the FAME concentration in the biodiesel product was 96.5%

Valorization of walnut shell ash as a catalyst for biodiesel production

The catalytic activity of the walnut shell ash was investigated in the biodiesel production by the sunflower oil methanolysis. The catalyst was characterized by the TG-DTA, XRD, Hg porosimetry, Ny physisorption, SEM, and Hammett method. In addition, the effects of the catalyst loading and the methanolto-oil molar ratio on the methyl esters synthesis were tested at the reaction temperature of 60 degrees C. The walnut shell ash provided a very fast reaction and a high FAME content (over 98%). As the reaction occurred in the absence of triacylglycerols mass transfer limitation, the pseudo-first-order model was employed for describing the kinetics of the reaction. The catalyst was successfully reused four times after the regeneration of the catalytic activity by recalcination at 800 degrees C