WebMonitoring software system: Finite state machines for monitoring the web

This paper presents a software system called WebMonitoring. The system is designed for solving certain problems in the process of information search on the web. The first problem is improving entering of queries at search engines and enabling more complex searches than keyword-based ones. The second problem is providing access to web page content that is inaccessible by common search engines due to search engine’s crawling limitations or time difference between the moment a web page is set up on the Internet and the moment the crawler finds it. The architecture of the WebMonitoring system relies upon finite state machines and the concept of monitoring the web. We present the system’s architecture and usage. Some modules were originally developed for the purpose of the WebMonitoring system, and some rely on UNITEX, linguistically oriented software system. We hereby evaluate the WebMonitoring system and give directions for further development

Clinical significance of the method for thoracic indices assessment in diagnosing and treatment of pectus excavatum in children

Cilj: Proveriti da li je moguće promeniti način CT verifikacije Hallerovog indeksa u okviru preoperativne pripreme pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, uz utvrđivanje fiziološkog opsega vrednosti indeksa, njegove zavisnosti od uzrasta i pola, kao i respiratorne faze u kojoj se CT pregled izvodi. Utvrditi značaj vrednosti indeksa korekcije, indeksa asimetrije i indeksa torzije sternuma. Proveriti i mogućnost smanjivanja efektivne doze jonizujućeg zračenja kod primene CT tehnike jednog skena (single slice). Materijal i metod rada: Ispitivanje se sastojalo iz prospektivne studije koja je obuhvatila 30 pacijenata sa pektus ekskavatumom uz CT snimanje (single slice) u respiratornim fazama: ekspirijum i inspirijum. Na dobijenim snimcima su izračunati pored Halerovog indeksa i indeksi asimetrije, korekcije i sternalne torzije. Prema dobijenim rezultatima merenja i izračunavanja, donošena je odluka o načinu terapijskog tretmana. U retrospektivnoj studiji, urađena je analiza 100 CT pregleda grudnog koša kod dece gde nije verifikovan pectus excavatum, uz kalibriranje vrednosti indeksa u odnosu na uzrast i pol pacijenata. Retrospektivno istraživanje je obuhvatilo i analizu dodatnih 30 CT pregleda grudnog koša pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, koji su dijagnostikovani i/ili operisani. Kod svih operisanih pacijenata je primenjenja Nusova operativna tehnika. U ovoj grupi pacijenata je izračunata srednja vrednost efektivne doze jonizujućeg zračenja, a dobijene vrednosti su potom komparirane sa efektivnim dozama koje su dobijene niskodoznim CT pregledima grudnog koša uz primenu novog protokola ("single-slice" tehnika u respiratornim fazama inspirijuma i ekspirijuma). Rezultati: Fiziološki opseg vrednosti Haller-ovog indeksa u populaciji zdravih pacijenata se kretao od 1,47 do 3,17 i u proseku je iznosio 2,23±0,32 (znatna pozitivna korelacija uzrasta i vrednosti HI). Na osnovu rezultata Man-Vitnijevog testa nije postojala polna razlika u posmatranoj grupi. Haller-ov indeks u grupi dijagnostikovane/operisane dece je u proseku iznosio 3,39 i kretao se u intervalu od 2,23 do 5,72 (korelacija između uzrasta ovih pacijenata i Haller-ovog indeksa je bila neznatna i negativna). Utvrđena je zavisnost veličine Haller-ovog indeksa od respiratorne faze u kojoj se CT pregled izvodi. Tako su prosečne vrednosti Haller-ovog indeksa u inspirijumu dece sa dijagnostikovanim deformitetom iznosile 2,69±0,76. Kod dece ove grupe u ekspirijumu vrednosti Haller-ovog indeksa su iznosile 3,49±1,19. U inspirijumu su samo 3/32 (9%) ispitanika imali vrednost HI preko 3,25 (granična vrednost za operativni tretman), dok ih je u ekspirijumu bilo znatno više 13/32 (41%), što je statistički značajna razlika (χ2=6,250; df =1; p=0,012). "Single-slice" tehnika CT pregleda u inspirijumu i ekspirijumu 20-25 puta smanjuje efektivnu dozu jonizujućeg zračenja. Zaključak: Vrednost Haller-ovog indeksa raste sa uzrastom deteta, dok nije utvrđena zavisnost Haller-ovog indeksa od pola. Moguće je promeniti načini CT verifikacije Haller-ovog indeksa u preoperativnoj pripremi za Nuss-ovu operaciju primenom "single-slice" tehnike u ekspiratornoj fazi. Osim Hallerovog indeksa, korisno je određivati i indeks korekcije, indeks asimetrije i indeks sternalne rotacije. Predlaže se protokol standardne preoperativne pripreme i lečenja pacijenata dečjeg uzrasta sa deformitetom grudnog koša po tipu pektus ekskavatuma, sa ciljem njegove primene u svakodnevnom radu u institucijama koje se bave ovim problemom, a u cilju poboljšanja kvaliteta dijagnostikovanja i krajnjeg ishoda lečenja.Aim: The aim of this study was to verify whether it is possible to change the way of CT verification of Haller index (HI), as part of preoperative preparation for patients with pectus excavatum, with the determination of the physiological range of the index value, its dependence on the age and sex, as well as the respiratory phase during which the scan is performed. Also, the aim was to determine the significance of correction, asymmetry and sternal torsion indices values. Evaluate the possibility of reduction the effective dose of ionizing radiation using a single slice CT scan technique. Materials and methods: The study consisted of prospective study that included evaluation of CT scans (single slice technique) of 30 patients with pectus excavatum in both respiratory phases: expirium and inspirium. Haller index and indices of asymmetry, correction and sternal torsion were measured. The decision for the treatment was made according to the results of measurements and calculations of these indices. In retrospective study, 100 CT scans of the chest in children without the deformity (pectus excavatum) were analyzed, and the index value was calibrated depending on the age and gender. The retrospective study also included the analysis of another 30 CT scans in patients who were operated or diagnosed with pectus excavatum. Nuss procedure was used in all operated patients. In this group of patients the median value of effective dose of ionizing radiation was calculated, and the values were compared with the effective dose obtained using low-dose CT examinations applied in the new protocol (single-slice technique in inspiratory and expiratory respiratory phases). Results: The physiological range of Haller index value in healthy patients was from 1.47 to 3.17 and average value was 2.23±0.32 (significant positive correlation between age and the value of HI). Results of Mann- Whitney test did not demonstrate any difference between gender in the observed group. In the group of patients who were operated/diagnosed with pectus excavatum the average value of Haller index was 3.39 within the range of 2.23 to 5.72 (correlation between the age of these patients and Haller index was negative, but not significant). The dependence of the Haller index value and certain respiratory phase during which the CT scan was performed also was determined. Thus, the average value of Haller index in inspirium in children with diagnosed deformity was up to 2.69±0.76. In the same group of patients the value of Haller index in expirium was up to 3.49±1.19. Only 3/32 (9%) patients had HI value over 3.25 (a boundary value for surgical treatment) during inspirium, while 13/32 (41%) patients had it in expirium, this data showed statistically significant difference (χ2=6.250; df=1; p=0.012). Single-slice CT technique during the inspiratory and expiratory phase reduces 20-25 times the effective dose of ionizing radiation. Conclusion: The value of Haller index increases with the age, but its dependence on the gender was not determined. It is possible to change the way of CT verification of Haller index in preoperative preparation for the Nuss operation using the "single-slice" technique in exspiratory phase. In addition to Haller index it is useful to determine correction index, the index of asymmetry and the index of sternal rotation as well. This protocol is proposed for standard preoperative preparation and treatment of pediatric population with pectus excavatum with the aim of its application in daily work in institutions that deal with this problem, but also to improve the quality of diagnosis and treatment outcomes

Clinical significance of the method for thoracic indices assessment in diagnosing and treatment of pectus excavatum in children

Cilj: Proveriti da li je moguće promeniti način CT verifikacije Hallerovog indeksa u okviru preoperativne pripreme pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, uz utvrđivanje fiziološkog opsega vrednosti indeksa, njegove zavisnosti od uzrasta i pola, kao i respiratorne faze u kojoj se CT pregled izvodi. Utvrditi značaj vrednosti indeksa korekcije, indeksa asimetrije i indeksa torzije sternuma. Proveriti i mogućnost smanjivanja efektivne doze jonizujućeg zračenja kod primene CT tehnike jednog skena (single slice). Materijal i metod rada: Ispitivanje se sastojalo iz prospektivne studije koja je obuhvatila 30 pacijenata sa pektus ekskavatumom uz CT snimanje (single slice) u respiratornim fazama: ekspirijum i inspirijum. Na dobijenim snimcima su izračunati pored Halerovog indeksa i indeksi asimetrije, korekcije i sternalne torzije. Prema dobijenim rezultatima merenja i izračunavanja, donošena je odluka o načinu terapijskog tretmana. U retrospektivnoj studiji, urađena je analiza 100 CT pregleda grudnog koša kod dece gde nije verifikovan pectus excavatum, uz kalibriranje vrednosti indeksa u odnosu na uzrast i pol pacijenata. Retrospektivno istraživanje je obuhvatilo i analizu dodatnih 30 CT pregleda grudnog koša pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, koji su dijagnostikovani i/ili operisani. Kod svih operisanih pacijenata je primenjenja Nusova operativna tehnika. U ovoj grupi pacijenata je izračunata srednja vrednost efektivne doze jonizujućeg zračenja, a dobijene vrednosti su potom komparirane sa efektivnim dozama koje su dobijene niskodoznim CT pregledima grudnog koša uz primenu novog protokola ("single-slice" tehnika u respiratornim fazama inspirijuma i ekspirijuma). Rezultati: Fiziološki opseg vrednosti Haller-ovog indeksa u populaciji zdravih pacijenata se kretao od 1,47 do 3,17 i u proseku je iznosio 2,23±0,32 (znatna pozitivna korelacija uzrasta i vrednosti HI). Na osnovu rezultata Man-Vitnijevog testa nije postojala polna razlika u posmatranoj grupi. Haller-ov indeks u grupi dijagnostikovane/operisane dece je u proseku iznosio 3,39 i kretao se u intervalu od 2,23 do 5,72 (korelacija između uzrasta ovih pacijenata i Haller-ovog indeksa je bila neznatna i negativna). Utvrđena je zavisnost veličine Haller-ovog indeksa od respiratorne faze u kojoj se CT pregled izvodi. Tako su prosečne vrednosti Haller-ovog indeksa u inspirijumu dece sa dijagnostikovanim deformitetom iznosile 2,69±0,76. Kod dece ove grupe u ekspirijumu vrednosti Haller-ovog indeksa su iznosile 3,49±1,19. U inspirijumu su samo 3/32 (9%) ispitanika imali vrednost HI preko 3,25 (granična vrednost za operativni tretman), dok ih je u ekspirijumu bilo znatno više 13/32 (41%), što je statistički značajna razlika (χ2=6,250; df =1; p=0,012). "Single-slice" tehnika CT pregleda u inspirijumu i ekspirijumu 20-25 puta smanjuje efektivnu dozu jonizujućeg zračenja. Zaključak: Vrednost Haller-ovog indeksa raste sa uzrastom deteta, dok nije utvrđena zavisnost Haller-ovog indeksa od pola. Moguće je promeniti načini CT verifikacije Haller-ovog indeksa u preoperativnoj pripremi za Nuss-ovu operaciju primenom "single-slice" tehnike u ekspiratornoj fazi. Osim Hallerovog indeksa, korisno je određivati i indeks korekcije, indeks asimetrije i indeks sternalne rotacije. Predlaže se protokol standardne preoperativne pripreme i lečenja pacijenata dečjeg uzrasta sa deformitetom grudnog koša po tipu pektus ekskavatuma, sa ciljem njegove primene u svakodnevnom radu u institucijama koje se bave ovim problemom, a u cilju poboljšanja kvaliteta dijagnostikovanja i krajnjeg ishoda lečenja.Aim: The aim of this study was to verify whether it is possible to change the way of CT verification of Haller index (HI), as part of preoperative preparation for patients with pectus excavatum, with the determination of the physiological range of the index value, its dependence on the age and sex, as well as the respiratory phase during which the scan is performed. Also, the aim was to determine the significance of correction, asymmetry and sternal torsion indices values. Evaluate the possibility of reduction the effective dose of ionizing radiation using a single slice CT scan technique. Materials and methods: The study consisted of prospective study that included evaluation of CT scans (single slice technique) of 30 patients with pectus excavatum in both respiratory phases: expirium and inspirium. Haller index and indices of asymmetry, correction and sternal torsion were measured. The decision for the treatment was made according to the results of measurements and calculations of these indices. In retrospective study, 100 CT scans of the chest in children without the deformity (pectus excavatum) were analyzed, and the index value was calibrated depending on the age and gender. The retrospective study also included the analysis of another 30 CT scans in patients who were operated or diagnosed with pectus excavatum. Nuss procedure was used in all operated patients. In this group of patients the median value of effective dose of ionizing radiation was calculated, and the values were compared with the effective dose obtained using low-dose CT examinations applied in the new protocol (single-slice technique in inspiratory and expiratory respiratory phases). Results: The physiological range of Haller index value in healthy patients was from 1.47 to 3.17 and average value was 2.23±0.32 (significant positive correlation between age and the value of HI). Results of Mann- Whitney test did not demonstrate any difference between gender in the observed group. In the group of patients who were operated/diagnosed with pectus excavatum the average value of Haller index was 3.39 within the range of 2.23 to 5.72 (correlation between the age of these patients and Haller index was negative, but not significant). The dependence of the Haller index value and certain respiratory phase during which the CT scan was performed also was determined. Thus, the average value of Haller index in inspirium in children with diagnosed deformity was up to 2.69±0.76. In the same group of patients the value of Haller index in expirium was up to 3.49±1.19. Only 3/32 (9%) patients had HI value over 3.25 (a boundary value for surgical treatment) during inspirium, while 13/32 (41%) patients had it in expirium, this data showed statistically significant difference (χ2=6.250; df=1; p=0.012). Single-slice CT technique during the inspiratory and expiratory phase reduces 20-25 times the effective dose of ionizing radiation. Conclusion: The value of Haller index increases with the age, but its dependence on the gender was not determined. It is possible to change the way of CT verification of Haller index in preoperative preparation for the Nuss operation using the "single-slice" technique in exspiratory phase. In addition to Haller index it is useful to determine correction index, the index of asymmetry and the index of sternal rotation as well. This protocol is proposed for standard preoperative preparation and treatment of pediatric population with pectus excavatum with the aim of its application in daily work in institutions that deal with this problem, but also to improve the quality of diagnosis and treatment outcomes

Ekonomska efektivnost mehanizovnog ubiranja kamilice

Chamomile as a medicinal and aromatic plant is very important as a valuable product in the world market of medicinal plants. Regardless of that, there have been only a few researches so far concerning economic effects of its production. Costs of chamomile harvesting require special attention as these costs, as a rule, account for a major portion in the structure of total costs. The aim of this paper is to show when it is economically justified to substitute hand harvesting by machine harvesting as well as to determine the largest possible investment in purchasing different harvesters for chamomile harvesting. For that purpose were used enterprise budgeting (analytical calculations) of chamomile production, calculations of costs of agricultural machinery, as well as dynamic methods for investment evaluation (present value method). It was determined that it is economically justified to substitute hand harvesting with mechanized harvesting of chamomile on land area of over 2.5, i.e. 4 ha of chamomile, depending on the harvester type. If harvesters are used on land areas smaller than this economical effectiveness of the investments in purchasing them, i.e. their present value, depends on the harvester type and the land area on which chamomile is grown.Kamilica kao lekovita i aromatična vrsta je od velikog značaja, jer predstavlja značajan artikal na svetskom tržištu lekovitog bilja. Bez obzira na to, do sada postoji samo mali broj istraživanja koja se odnose na ekonomske efekte njene proizvodnje. Posebnu pažnju kod gajenja kamilice treba obratiti na troškove ubiranja, koji po pravilu imaju najveće učešće u strukturi ukupnih troškova. Cilj ovog rada je da utvrdi kada je ekonomski opravdano preći sa ručnog na mašinsko ubiranje kamilice i koliko se najviše može investirati u nabavku različitih kombajna za berbu kamilice. Da bi se to proverilo, korišćene su analitičke kalkulacije proizvodnje kamilice, kalkulacije rada poljoprivrednih mašina, kao i dinamičke metode za ocenu investicija (metod prinosne vrednosti). Utvrđeno je da je ekonomski opravdano preći sa ručnog na mehanizovano ubiranje kamilice na površinama koje prelaze 2,5 odnosno 4 ha kamilice, zavisno od tipa kombajna. Ako se kombajni koriste na površinama manjim od prethodno navedenih, ekonomska efektivnost investicija u njihovu nabavku, odnosno visina njihove prinosne vrednosti, zavisi od tipa kombajna i površine na kojoj se gaji kamilica

Optimization of mechanized harvesting of chamomile (Matricaria chamomilla L.)

Intenzivna proizvodnja kamilice (Matricaria chamomilla L.) podrazumeva proizvodnju gde se svi tehnološki postupci gajenja i prerade mogu obaviti sredstvima mehanizacije poljoprivrede na optimalan nacin i uz racionalan utrošak energije. Tema istraživanja u ovoj doktorskoj disertaciji je mehanizovan postupak ubiranja kamilice. Zahtevu za mehanizovanim postupkom ubiranja kamilice odgovorili su mnogi domaci i svetski proizvoaci poljoprivrednih mašina, koji su proizveli veci broj konstrukcija i tipova mašina koje se meusobno razlikuju, kako po tehnickim, konstruktivnim karakteristikama, tako i po kvalitetu rada i ostvarenim ucincima. Takva pojava je ovo istraživanje usmerila ka svestranom proucavanju odabrene teme sa ciljem izbora odgovarajuce mašine koja ce najbolje odgovarati uslovima rada na parcelama pod kamilicom. U tehnologiji proizvodnje kamilice proces ubiranja cvasti kamilice je tehnicko-tehnološki najzahtevniji i ima veliki uticaj kako na kvalitet dobijene droge, tako i na dobit ostvaren proizvodnjom. U ovoj disetaciji su ispitivana tri konstrukcijski i koncepcijski razlicita tipa kombajna za ubiranje kamilice. Praceni su tehnicki, tehnološki, biološki, meteorološki i eksploatacioni pokazatelji koji uticu na ocenu efikasnosti rada ispitivanih kombajna. Kao osnovne parametre treba izdvojiti režim rada, kvalitet i gubitke ostvarene tokom ubiranja, energetsku i ekonomsku opravdanost korišcenja pojedinih kombajna. U radu su primenjene tri metode optimizacije najuticajnijih parametara rada kombajna, kako bi se ustanovio optimalan kombajn i režim rada u odreenim agroekološkim uslovima, prema zadatim kriterijumima ocenjivanja. Tehnološka proizvodnost (ucinak) kombajna za ubiranje kamilice zavisi iskljucivo od radnog zahvata i brzine kretanja kombajna. Najveci prosecan ucinak postigao je kombajn A od 0,65 ha/h, pa kombajn B sa 0,57 ha/h i kombajn C sa 0,56 ha/h. Najmanju potrošnju goriva po jedinici površine su ostvarili kombajni u režimu rada V3, gde je najekonomicniji bio kombajn B sa potrošenih 23,86 l/ha, pa kombajn C sa 33,51 l/ha i kombajn A sa potrošnjom od 45,78 l/ha. Može se konstatovati da viši režim rada (veca brzina kretanja i broj obrtaja berackog ureaja) donosi i vece ukupne gubitke. Najvece prosecne ukupne gubitke ostvaruje kombajn A (39,77%) dok se kod kombajna B i C oni krecu oko 20%. Sva tri ispitivana kombajna, u sva tri režima rada, ostvaruju približan kvalitet ubiranja cvasti kamilice, narocito kada se posmatraju njihove prosecne vrednosti, kao i zbirno I i II kategorije kvaliteta (kombajn A: 68,5- 92,1%; kombajn B: 69,9-90,7%; kombajn C: 62,2-86,1%)...Intensive production of chamomile (Matricaria chamomilla L.) is the kind of production in which all technological processes of growing and processing chamomile can be carried out by mechanized agricultural resources in an optimal way and with a rational energy consumption. Topic of research in this doctoral dissertation is mechanized process of harvesting chamomile. Many domestic and international manufacturers of agricultural machinery have responded to the request for mechanized harvesting procedure chamomile and produced a number of constructions and types of machines, which differ in both the technical, structural characteristics, and quality of work and its effects. Such a phenomenon has directed this research towards a comprehensive study of the chosen topics, with the objective to recommend adequate machine that will best suit the work conditions on the chamomile fields. Harvesting chamomile blossom is technically and technologically the most demanding process in the chamomile production technology and has a great influence on both the quality of drugs received, and the income generated in production. In this dissertation, three structurally and conceptually distinct types of chamomile harvester were tested. We assessed the technical, biological, meteorological, and operating parameters that affect evaluating the efficiency of the examined harvesters. Working mode, quality and losses realized during the harvesting, as well as energetic and economic feasibility of using certain harvesters, should be emphasized as the basic parameters. Three optimization methods were used for optimizing the most influential parameters of combine work, in order to determine the optimal combine and the working under the specific ecological conditions, according to the specified evaluation criteria. Technological productivity (efficiency) of chamomile harvester depends only on the working width and speed of the combine. The highest average efficiency of 0.65 ha / h was achieved by harvester A, then harvester B with average 0.57 ha / h and finally harvester C with average 0.56 ha / h. The lowest fuel consumption per unit area achieved harvesters working in V3 mode, where the harvester B was the most economical and consumed 23.86 l / ha, followed by the harvester C with 33.51 l / ha and the harvester A with 45.78 l / ha. It can be concluded that the “higher” mode (with higher travel speed and speed of turning - rpm) brings greater total losses. Harvester A realized the highest average total losses (39.77%) while with combine B and C they were about 20%. All three harvesters, in all three working modes, achieve the approximately equal quality of harvested chamomile blossom, especially when considering their average values, as well as the sum of I and II category (A harvester: 68.5 to 92.1%; harvester B: 69.9 to 90.7%; harvester C: 62.2 to 86.1%)..

Effects of processing meliorative tillage on the soils with heavy mechanical type in maize production

Soils with heavy mechanical type of composition demand a cultivation system that ensures preservation of natural potential and fertility resources. This system must also prevent degrading processes and ensure an optimal water flow within the soil, with an optimal usage of energy and labor. This paper presents the results of the application of the machines and tools for new technologies in maize production. We analyzed the influence of meliorative tillage and effect of conventional tillage systems on maize production.

Poljoprivredna mehanizacija protiv prolećnih mrazeva

When it comes to fruit and wine production, one of the serious problems for many producers in Serbia is the frost. Frost occurs in a relatively short period of time and, depending on the timing and intensity, can cause greater or less damage to the cultivated crop. Damage can be reflected in a significant decrease in the crop in the current production year, but in addition, the damage can also have a long-term character.Kada je u pitanju voćarsko - vinogradarska proizvodnja jedan od ozbiljnih problema koji muči mnoge proizvođače u Srbiji jeste mraz. Mraz se javlja u relativno kratkom vremenskom periodu i zavisno od vremena javljanja i intenziteta može naneti veće ili manje štete gajenoj kulturi. Štete se mogu ogledati u značajnom umanjenju roda u tekućoj proizvodnoj godini, ali pored toga štete mogu imati i dugoročni karakter

Analiza efikasnosti rada sistema toplotne pumpe za hlađenje svežeg mleka sa predhlađenjem i mogućnošću iskorišćenja otpadne toplote za dogrevanje potrošne vode

Contemporary livestock production implies production of highly valuable, biologically and chemically safe products. Dairy production has no exception too. On the contrary, the quality standards for raw milk are highly increased. The quality of raw milk is defined by its chemical composition and the total count of microorganisms in control volume. In this paper we discussed the performance of advanced system for heat recovery from raw milk and its application in the process of preheating and preparation of process water. The energy and exergy efficiency of one of such systems were analyzed. It was determined that the implementation of the system for milk cooling with precooling and using the waste heat for preheating process water could achieve significant savings. The system consists of 'milk to water' heat pump, pre-cooler for milk cooling and storage tank for process water with heating possibility. Values of exergy efficiency of each component of system and potential improving of components performances were determined. Also, the exergy efficiency and potential improvement of complete system were determined.Savremena stočarska proizvodnja podrazumeva proizvodnju visoko vrednih, biološki i hemijski bezbednih proizvoda. Proizvodnja mleka nije izuzetak, naprotiv, norme kvaliteta sirovog mleka su sve strožije. Kvalitet sirovog mleka je određen njegovim hemijskim sastavom i ukupnom brojnošću mikroorganizama u kontrolnoj zapremini. U ovom radu biće razmatran rad naprednog sistema za rekuperaciju toplote iz svežeg mleka koja se potom koristi u procesu dogrevanja i pripreme potrošne vode. Primenom sistema za hlađenje mleka sa predhlađenjem i korišćenjem dobijene toplote za zagrevanje potrošne vode mogu se postići značajne uštede. U radu je analizirana energetska i eksergetska efikasnost rada jednog ovakvog sistema. Sistem se sastoji od toplotne pumpe 'mleko-voda', predhladnjaka za hlađenje svežeg mleka i skladišnika potrošne tople vode sa mogućnošću njenog dogrevanja. Ustanovljene su veličine eksergetske efikasnosti komponenata sistema i potencijal poboljšanja svake od komponenata u sistemu. Takođe, ustanovljena je eksergetska efikasnost celokupnog sistema i potencijal njegovogpoboljšanja

Structural characteristics of the mixed spruce - fir - beech forests on Mountain Bjelasica in Montenegro

Biogradska Gora National Park in Montenegro is part of the Bjelasica Mountain which belongs to the montane region of the Dinaric Alps. Biogradska Gora is one of the largest long-term preserved forests in the Southeast Europe. In this paper there were compared the main structural characteristics of the old-growth mixed forest of spruce (Picea abies L.), fir (Abies alba L.) and beech (Fagus moesiaca (Domin, Maly) Czecz.), from the preserved area of the Biogradska Gora, with similar managed forests from the same mountain. Basic insight into the structural characteristics of forests of spruce, fir and beech was obtained by analyzing tree species composition and two basic structural elements - number of trees and wood volume per unit area. The obtained data provides overview of the structural characteristics of these forests. The results revealed the production potential of the studied mixed forests. The average quantity of standing volume in old-growth forests of Biogradska Gora indicates very valuable and productive forest ecosystems. Presented data shows that forest ecosystems of spruce, fir and beech in the protected area of the National Park Biogradska Gora are characterized by structurally irregular forests with presence of old trees with relevant growing stock and optimal balance of beech and conifer species, while in managed forests on the same mountain, growing stock is very low and with structure which is far from optimal

Procena vrednosti objekata za čuvanje stočne hrane

In order to keep milk production economically effective in contemporary business environment, it is necessary to use appropriate types and combinations of animal feed. This means that the bulky part of the meal for the cows has to be based on the use of corn silage, with the addition of small amounts of alfalfa hay. This combination of forage allows for high milk production per cow, while keeping production costs low. However, this concept of nutrition is related to high investments in appropriate facilities for the storage of animal feed. To evaluate the economic effectiveness of investments in modern feed storages, a method of present value of investment is used. Determined present value of investment is compared with the corresponding construction costs of the objects at different prices of animal feed and various assumed losses due to its inadequate storage.Da bi u savremenim uslovima poslovanja proizvodnja mleka bila ekonomski opravdana, neophodno je koristiti odgovarajuće vrste i kombinacije stočnih hraniva. To znači da se kabasti deo obroka za krave mora zasnivati na korišćenju kukuruzne silaže, uz dodatak manje količine sena lucerke. Ovakva kombinacija kabastih hraniva omogućava visoku proizvodnju mleka po kravi, uz održavanje troškova proizvodnje na niskom nivou. Međutim, navedeni koncept ishrane vezan je za visoka investiciona ulaganja u odgovarajuće objekte za smeštaj stočne hrane. Da bi se utvrdila ekonomska efektivnost investicionih ulaganja u moderne objekte za čuvanje stočne hrane, korišćena je metoda prinosne vrednosti investicije. Utvrđena prinosna vrednost poređena je sa odgovarajućim troškovima izgradnje navedenih objekata, pri različitim cenama stočne hrane i različitim pretpostavljenim gubicima usled njenog neadekvatnog skladištenja