58 research outputs found

    Ocena aktivnosti disanja u albičnom luvisolu kontaminiranom sa Zn i Ni tokom gajenja jare uljane repice

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    In almost all industrially developed regions of the Russian Federation, the soil is contaminated with heavy metals (HM) often in concentrations which exceed limits of safety. This contamination causes degradation of agricultural land, which underlines the importance of the complex continuous monitoring of the dynamics of on-going changes in urban ecosystems against the background of natural processes. Quantitative assessment of the environmental sustainability of the soil according to the biological indicators of its condition is of enormous importance, in particular the balance of microbial carbon in soils, which are under varying degrees of anthropogenic pressure. Experiments were carried out to determine the phytoremediation potential of the spring rapeseed plants on soil contaminated with heavy metals. The aim of the study was to assess the respiratory activity of albic luvisol at different levels of its contamination with zinc and nickel under the conditions of a growing experiment with spring rapeseed plants. The experimental data on the respiratory activity of soil artificially contaminated with zinc and nickel in the dose range of 400-800 and 30-60 mg kg-1 of soil respectively, showed that microbial activity had a strong positive correlation with the presence of spring rapeseed plants in the vessels and weak correlation on the presence of toxic elements in the soil. According to the respiratory activity of albic luvisol, it was found that in the first 13 days of vegetation, cultivation of spring rapeseed plants had a positive effect on the sustainability of soil microbiocenosis to complex pollution with zinc and nickel.U skoro svim industrijski razvijenim regionima Ruske Federacije zemljište je kontaminirano teškim metalima, često u koncentracijama koje prelaze sigurne granice. Ova kontaminacija izaziva degradaciju poljoprivrednog zemljišta, što ističe važnost kompleksnog kontinuiranog praćenja dinamike neprekidnih promena u urbanim ekosisemima u odnosu na prirodne procese. Kvantitativna procena ekološke održivosti zemljišta prema biološkim pokazateljima njegovog stanja je od ogromnog značaja, posebno ravnoteža mikrobnog ugljenika u zemljištima koja imaju različit stepen antropogenog pritiska. Eksperimenti su sprovedeni u svrhu određivanja fitoremedijacionog potencijala biljaka uljane repice na zemljištu kontaminiranom teškim metalima. Cilj istraživanja bila je procena respiratorne aktivnosti albičkog luvisola, pri različitim nivoima kontaminacije cinkom i niklom u uslovima vegetativnog eksperimenta sa biljkama uljane repice. Eksperimentalni podaci o respiratornoj aktivnosti tla veštački kontaminiranog cinkom i niklom u rasponu doza od 400-800, odnosno 30-60 mg kg-1 zemljišta, pokazali su da mikrobna aktivnost ima jaku pozitivnu korelaciju sa prisustvom biljaka uljane repice u posudama i slabu u odnosu na prisustvo toksičnih elemenata u tlu. Prema respiratornoj aktivnosti albičkog luvisola, utvrđeno je da je u prvih 13 dana vegetacije gajenje jarih biljaka uljane repice pozitivno uticalo na održivost mikrobiocenoze zemljišta u uslovima kompleksnog zagađenja cinkom i niklom

    Prostorna analiza tala i utjecaj na produktivnost u gospodarskoj jedinici Mužljanski rit

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    The paper presents analysis of soil spatial distribution and productivity of Populus x euramericana I-214 forest cultures in forest management unit (hereinafter: FMU) Muzljanski rit. Soil cover in the FMU is heterogeneous in relation to position and altitude in floodplain. Analysis were conducted on eugley and humogley soil types. Eugley, soil type, was delineated according to physiologically active soil depth as α, β or β/γ gley soils and humogley was delineated as one soil unit. Cultures of the poplar clones Populus x euramericana I-214 are found on at least two but usually more different site types within the same forest management section (18.43 %). Single forest management section is a by definition a single forest spatial unit having similar ecologic factors. Aim of our research was to enable consistent forest section delineation, based on the interaction of soil productivity properties and distribution as well as Populus x euramericana I-214 productivity dataset. Based on our anaysis (spatial analysis of raster layers of soil systematic unit distribution-soil subunit, digital elevation model and productivity according to inner delineation of FMU Muzljanski rit), the resuts show eugley share in lower systematic soil unit. The results show contribution of lower systematic units of eugley in forest managemet section/culture. We found a raising trend of α and β-gley, as well as humogley. On one side the higher contribution of this sistematic units indicates reduction in the forest culture yield. On the other side higher contribution of β/γ gley indicates an increase of culture yeald. The Populus x euramericana I-214 cultures are spatialy concentrated, extending over soil units with different characteristics, pointing in alternative economicaly justified section delineation, based on the soil types.Razumijevanje produktivnosti drveća u gospodarskim jedinicama vezano je za poznavanje više stanišnih čimbenika. U radu se prikazuju istraživanja s obzirom na rasprostranjenost tala, dajući im veću važnost u odnosu na izbor klona, vodni režim, klimatske ekstreme, kao i postupak obnove nasada. Opravdanost navedenog pristupa je vezana za više provedenih istraživanja, u kojima je jedan od osnovnih čimbenika tip tla, a s njime i odgovarajuća vrsta drveća.Pregled prostorne rasprostranjenosti tala omogućeno je razvojem programskih paketa za prostornu analizu geoinformacijskih podataka. U radu je prikazana analiza prostorne raspodjele tala i produktivnosti nasada Populus x euramericana I-214 gospodarske jedinice (GJ) Mužljanski Rit. Definiranju rasprostranjenosti tala u GJ Mužlјanski rit prethodila je izrada modela terena. Model terena napravljen je na bazi osnovne državne karte (R 1:5000) za definiranje mikrorelјefa. Svaka poznata točka je osim vrijednosti na x i y osi, dobila vrijednost i na z osi. U programskom paketu ArcGIS je izvršena interpolacija, a rezultat je 3D model terena u GJ Mužljanski rit na površini od približno 1820 ha. Na ovaj način je omogućena analizirati ekvidistance na 10 cm na prostoru gospodarske jedinice. Prostornom analizom su prema Klasifikaciji zemlјišta Jugoslavije (Škorić i sur., 1985) determinirani različiti tipovi i niže sistematske jedinice tala. Prethodno navedena klasifikacija je nadopunjena podjelom na fiziološki aktivnu dubinu profila prema Wildeu (1940), zbog pretpostavljene različite produktivnosti tala ovisno o vrsti stabala koja će se tamo uzgajati. Postupak je na ovaj način definirao područja niza i greda na prostoru čitave GJ, te je poslužio kao osnova za daljnje analize. Mrežom pedoloških profila su definirani tipovi tala. Rezultati istraživanja ukazuju da je pokrov tla u istraživanoj GJ heterogen, te su kao tipovi tla determinirani euglej i humoglej. Podjela na niže sistematske jedinice kod eugleja je vezana za fiziološki aktivnu dubinu profila i to na α, β ili β/γ glej (ograničavajući čimbenik je stagnacija podzemne vode u profilu). Posljedica je 18,43% nasada Populus x euramericana I-214 koji se nalazi na dvije ili više različitih vrsta sustavnih jedinica tala, unutar istog odsjeka, u dijelu šume koja tvori glavnu prostornu jedinicu sa sličnom ekologijom. Povećanje ili smanjenje udjela sustavne jedinice tla dovodi do postizanja različite produktivnosti. U radu je utvrđena potreba podjele eugleja kao tipa tla na niže sistematske jedinice. Rezultati istraživanja ukazuju da trendovi povećanja udjela α i β-gleja u tlu, kao i humogleja, utječu na smanjenje prinosa nasada Populus x euramericana I-214, dok udio β/γ-gleja (u statističkoj značajnosti od 0,3745) pozitivno korelira s volumenom nasada Populus x euramericana I-214. Iz rezultata je također vidljivo da je mali udio α gleja (do 10%) dovoljan po površini odsjeka da bi doveo do smanjenja produktivnosti nasada Populus x euramericana I-214, dok je taj udio kod β-gleja nešto veći te ne bi trebao prelaziti 20%, odnosno najviše 30%. Nasadi Populus x euramericana I-214 prostorno su koncentrirani, što ukazuje na alternativnu ekonomski održivu podjelu na temelju karakteristika tala uz izbor odgovarajuće vrste drveća. Na području niza je u najvećoj mjeri zastupljen euglej (fiziološki α i β glej) i potrebno ih je izbjegavati, budući da i mali udio navedenih sustavnih jedinica zemljišta bitno utječe na produktivnost, a posljedično i na sortimentne strukture nasada Populus x euramericana I-214. U najvećem broju slučajeva, kao zamjenska vrsta na humoglejevima i fiziološki plićim sustavnim jedinicama bio bi hrast lužnjak kao stabilna i vitalna vrsta. Na osnovi prostornog rasprostranjenja tala to se vrlo jasno može definirati, a u konačnici se i ispunjavaju ostale funkcije šuma

    Dense poplar plantations as the raw material for the production of energy

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    The higher heating value of wood and bark was determined for several poplar (Populus spp) clones. The study included the juvenile one year old plants of the following clones: P.×euramericana cl. ostia, P. nigra cl.53/86, P. deltoides cl. PE 19/66, P.×euramericana cl. I-214, P. deltoides cl. S6-7 and P.×euramericana cv. robusta. By using FVI which takes into account ash content, wood bulk density, and moisture content, it was determined that poplar wood can be a significant energy raw material, primarily thanks to its short rotation cycle and a very high wood volume increment. Significant differences were determined in the values of wood basic density which affect the higher heating value of the study poplar clones, and consequently the yield (weight) of biomass produced per unit area of dense plantations. This is reflected also on the estimated amount of energy that can be produced by the combustion of biomass of the whole one year old plants

    ASIMETERS IN THE REGIONAL AND LOCAL DEVELOPMENT OF THE FEDERATION OF BIH

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    Ideja rada je da se mapiraju prostorne cjeline bazirane na socio-ekonomskim obilježjima kako bi se dala potpora i osnova politici regionalnog razvoja, apliciranjem softverskog riješenja R projecta. Rad pokazuje da se korištenjem različitih statističkih metoda mogu analitički izdvojiti jedinice lokalne samouprave pogodnije za određeni set mjera i instrumenata regionalne politike. Promatrani prostor čine jedinice lokalne samouprave (JLS) (gradovi i općine) u Federaciji Bosne i Hercegovine. Klasifikacija je izvršena primjenom metoda koeficijenta korelacije, a zasniva se na setu socio-ekonomskih pokazatelja razvoja. Temeljem odabranih društvenih, ekonomskih i demografskih pokazatelja, korištenjem koreficijenta korelacije, dobivaju se jedinice lokalne samouprave koje predstavljaju glavne determinante društvenogo-ekonomksog razvoja analiziranog prostora.The idea of this ork is to map development level of local units based in order to support and base the policy of regional development by applying the software solution of the R project. The paper explain different statistical methods can analytically distinguish local self-government units that are more suitable for a certain set of measures and instruments regional policy. The observed space is made up of units of local self-government (JLS) (cities and municipalities) in the Federation of Bosnia and Herzegovina. Classification was performed using the coefficient of correlation method, based on a set of socio-economic indicators of development. Based on the selected social, economic and demographic indicators, using correlation corpus, local self-government units are provided, which represent the main determinants of socio-economic development of the analyzed space

    Ispitivanje kompresivne čvrstoće kalcijum-silikatnih cemenata

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    Introduction The aim of this study was to compare compressive strength (Cs) of new nanostructural calcium silicate based cement (nCS) with commercial calcium silicate cement and conventional GIC. Methods Four nanostructural materials were tested: nanostructural calcium silicate based cement (nCS) (Jokanović et al.), MTA Plus (Cerkamed, Poland), Fuji IX (GC Corporation, Japan) and Ketac Universal Aplicap (3M ESPE, USA). Five samples of each material were mixed in accordance with manifecturer's guidelines and positioned in metal moulds (ϕ4mm and 6mm). Compressive strength (Cs) expressed in MPa was determined after 24 hours, 7 days and 28 days respectively. Measurements were performed on universal testing equipment (Tinius Olsen, USA) at a crosshead speed of 1mm/min. For processing the results one-way ANOVA and post-hoc test were used. Results The highest values of compressive strength after 24h was found in conventional GIC Fuji IX (mean 38.56±13.31) and Ketac Universal (mean 40.77±7.96). Calcium silicate cements after 24h showed low values of compressive strength (MTA Plus 5.91±0.28 MPa, nCS 1.35±0.36 MPa). After 7 days, FUJI IX 47.42±9.33 MPa and Ketac Universal 35.25±10.60 MPa showed higher value of compressive strength than MTA Plus (15.09±2.77 MPa) and nCS (11.06±0.88 MPa). After 28 days the Cs value for conventional GIC Fuji IX was 48.03±7.82 MPa and Ketac Universal 36.65±11.13 MPa while for calcium silicate cements it was 16.47±1.89 MPa and nCS 14.39±1.63 MPa. There was statistically significant difference (p lt 0.05) in Cs between conventional GIC and CS cements after 24h, 7 and 28 days. Conclusions Calcium silicate cements initially showed lower values of compressive strength than conventional GIC that increased over time.Uvod Cilj ovog rada je bio da se proveri kompresivna čvrstoća (KČ) novog nanostrukturnog kalcijum-silikatnog cementa (nCS) i uporedi sa komercijalnim kalcijum-silikatnim cementom i konvencionalnim GJC u funkciji vremena. Materijal i metod Testirana su četiri materijala - nanostrukturni CS (Jokanović i sar.), MTA Plus (Cerkamed, Poland), Fuji IX (GC Corporation, Japan) and Ketac Universal Aplicap (3M ESPE, USA). Po pet uzoraka za svaki materijal je zamešano po proizvođačkom uputstvu i postavljano u metalne kalupe (ϕ 4 mm i 6 mm visoke). KČ, izražena u megapaskalima, merena je posle 24 sata i posle 7 i 28 dana na univerzalnoj test mašini (Tinius Olsen, USA) sa brzinom utiskivača od 1 mm/min. Dobijeni rezultati su statistički obrađeni one-way ANOVA i post hoc Tukey, s testovima. Resultati Posle 24 sata najveću KČ imao je FUJI IX (38,56 ± 13,31 MPa), zatim Ketac Univerzal (40,77 ± 7,96 MPa). Kalcijum-silikatni cementi su pokazali niže vrednosti KČ 24 sata posle mešanja i to MTA 5,91 ± 0,28, a nCS 1,35 ± 0,36 MPa. Posle sedam dana KČ za FUJI IX je bila 47,72 ± 9,33 MPa, a za Ketac Universal 35,25 ± 10,60 MPa, dok je vrednost za MTA bila 15,09 ± 2,77 MPa, a nCS 11,06 ± 0,88. Posle 28 dana KČ za FUJI IX je bila 48,03 ± 7,82 MPa, a za Ketac 36,65 ± 11,13 MPa. KČ kalcijum-silikatnih cemenata posle 28 dana je bila 16,47 ± 1,89 za MTA, a za nCS 14,39 ± 1,63 MPa, bez statističi značajne razlike između njih. Između konvencionalnih GJC i CS cemenata postoji statistički značajna razlika (p lt 0,05) posle 24 h, kao i posle 7 i 28 dana. Zaključak Kalcijum-silikatni cementi su inicijalno pokazali niže vrednosti KČ u odnosu na konvencionalne GJC, ali su se one povećavale u funkciji vremena

    Comparison of Different Wood Species as Raw Materials for Bioenergy

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    Background and Purpose: Most projections of the global energy use predict that biomass will be an important component of primary energy sources in the coming decades. Short rotation plantations have the potential to become an important source of renewable energy in Europe because of the high biomass yields, a good combustion quality as solid fuel, ecological advantages and comparatively low biomass production costs. Materials and Methods: In this study, the wood of black locust Robinia pseudoacacia, white willow Salix alba L., poplars Populus deltoides and Populus x euramericana cl.I-214, aged eight years were examined. Immediately after the felling, sample discs were taken to assess moisture content, ash content, the width of growth rings, wood densities and calorific values, according to the standard methodology. Results: The mean values of willow, poplar and black locust wood density were 341 kg/m3, 336 kg/m3 and 602 kg/m3,respectively. The average heating values of willow poplar and black locust wood were 18.599 MJ/kg, 18.564 MJ/kg and 21.196 MJ/kg, respectively. The FVI index (average values) was higher for black locust (17.186) than for poplar and willow clones, which were similar: 11.312 and 11.422 respectively. Conclusions: Black locust wood with a higher density, calorific value and ash content compared to poplar and willow wood proved to be a more suitable raw material as RES. However, it is very important, from the aspect of the application of wood of these tree species as RES, to also consider the influence of the biomass yield per unit area of the plantations established as “energy plantations”

    PREGLED DOSTIGNUĆA PRIMJENE BIM KONCEPTA U HRVATSKOJ, ČEŠKOJ, NJEMAČKOJ I SLOVENIJI

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    Building information modelling (BIM) may currently be considered the fastest developing concept in the field of construction management, aiming to become a global standard. Although the roots of the concept date back to the mid-1970s, some original expectations are still missing from its implementation. There has been a time gap between its theoretical and practical implementations. While the simultaneous development of information technologies is one reason for the implementation delay, other reasons remain unclear. This paper analyzes the gaps between theoretical and practical BIM application, as well as the legislation regarding BIM implementation in four countries (in alphabetical order: Croatia, the Czech Republic, Germany, and Slovenia). The paper additionally presents a survey of current practical BIM applications as well as general and theoretical feedback from construction projects that implemented BIM.Jedan od najbrže razvijajućih koncepata u domeni metoda i alata za upravljanje građevinskim projektima, uz konačni cilj da postane globalni standard, je informacijsko modeliranje građevina, tj. BIM. Iako se koncept razvija od sredine 1970-ih, neka od originalnih očekivanja u njegovoj primjeni i danas nedostaju. Očito je da postoji vremensko odstojanje između njegove teorijske i praktične primjene. Istovremeno, razvijanje nužnih alata informacijske tehnologije je jedan od razloga zašto praktična primjena zaostaje, no ostali razlozi su još nejasni. U ovome radu autori analiziraju razlike između teoretske i praktične primjene BIM-a u zemljama odakle dolaze (Hrvatske, Češke, Njemačke i Slovenije). Rad predstavlja pregled trenutačnih dostignuća primjene BIM-a te povratnih informacija s projekata na kojima je BIM primijenjen

    Chemical Composition and Antioxidant Capacity of Three Plum Cultivars

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    The aim of this study was to determine the chemical composition and antioxidants capacity of three plum cultivars, namely ‘Top’, ‘Elena’ and ‘Bistrica’. Fruits were harvested and following parameters were determined: dry matter, total acids (TA), total soluble solids (TSS), pH, vitamin C, total phenols, nonflavonoids and antioxidant capacity. Differences between cultivars for most of the chemical parameters were observed. The cultivar ‘Bistrica’ showed higher values of dry matter, TSS, vitamin C and pH value, while ‘Top’ had higher total acids value and lowest TSS, dry matter, vitamin C and pH. Total phenolics content varied from 157.70 mg in ‘Elena’ to 344.10 mg in ‘Bistrica’, expressed as gallic acid equivalents (GAE), on fresh weight basis. ‘Top’ contains the highest amount of non-flavonoids among cultivars studied. Therefore, ‘Bistrica’ and ‘Top’ show the highest antioxidant capacity, as well. There were significant differences between total phenolics and non-flavonoids content between ‘Elena’ and other two cultivars, while antioxidant capacity showed no significant difference (p ≤ 0.05). Total antioxidant capacity of fruits ranged from 3.10 mmol/kg in ‘Elena’ to 3.17 mmol/kg in ‘Top’ and ‘Bistrica’

    ACCURACY OF MODIFIED ALVARADO SCORE, ESKELINEN SCORE AND OHMANN SCORE IN DIAGNOSING ACUTE APPENDICITIS

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    Introduction: By processing the data of a large number of patients with abdominal pain, diagnostic scores whose implementation attempts to facilitate acute appendicitis diagnostics were developed. Modified Alvarado score, Ohmann score and Eskelinen score are used as assistance when setting the diagnosis and making a decision to undertake surgery. Aim: To assess accuracy of Alvarado score, Ohmann score and Eskelinen score in diagnosing acute appendicitis and to establish connection of total score of these scoring systems with histopathological degree of appendicitis. Subjects and methods: A cross-sectional study was conducted at the Department of Surgery of University Clinical Hospital Mostar. The study included 70 patients who underwent appendectomy and were scored before surgery. All tested persons were examined by experienced surgeon who took anamnesis, physical status and ordered laboratory diagnostic tests. Appendicitis was excluded or confirmed by means of histopathological diagnostics, and the degree of appendicitis was determined. Results: According to accuracy parameters (sensitivity, specificity, negative and positive predictive value), the score which was of highest value was Ohmann score, followed by Eskelinen score, while the lowest value was the one of modified Alvarado score. Total score in all three scoring systems follows the degree of appendicitis, but statistical significance was proven only for Ohmann and Eskelinen scores. Conclusion: Ohmann and Eskelinen scores can be useful in diagnosing acute appendicitis, predicting the degree of appendicitis, as well as assistance when making decision to undertake an operative procedure. Modified Alvarado score in our subjects did not prove sufficient value. Diagnostics of acute appendicitis still must be led by contemporary algorithms in which diagnostic scoring is implemented
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