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1.
Radon anomalies in soil gas caused by seismic activity
Boris Zmazek, Mladen Živčić, Ljupčo Todorovski, Sašo Džeroski, Janja Vaupotič, Ivan Kobal, 2004, izvirni znanstveni članek

Opis: At the Orlica fault in the Krško basin, combined barasol detectors were buried in six boreholes, two along the fault itself and four on either side of it, to measure and record radon activity, temperature and pressure in soil gas every 60 minutes for four years. Data collected have been analysed in a manner aimed at distinguishing radon anomalies resulting from environmental parameters (air and soil temperature, barometric pressure, rainfall) from those caused solely by seismic events. The following approaches have been used to identify anomalies: (i) ± 2σ deviation of radon concentration from the seasonal average, (ii) correlation between time gradients of radon concentration and barometric pressure, and (iii) prediction with regression trees within a machine learning program. In this paper results obtained with regression trees are presented. A model has been built in which the program was taught to predict radon concentration from the data collected during the seismically inactive periods when radon is presumably influenced only by environmental parameters. A correlation coefficient of 0.83 between measured and predicted values was obtained. Then, the whole data time series was included and a significantly lowered correlation was observed during the seismically active periods. This reduced correlation is thus an indicator of seismic effect.
Ključne besede: radon in soil gas, environmental parameters, earthquakes, correlation, regression trees, forecasting
Objavljeno v DKUM: 15.05.2018; Ogledov: 1714; Prenosov: 84
.pdf Celotno besedilo (271,01 KB)
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2.
POTENTIAL INDICATORS FOR Sustainability assessment of food production on the field level
Saša Štraus, 2012, doktorska disertacija

Opis: The issue of sustainable agriculture has attracted considerable attention. Sustainable agriculture encompasses economic viability, social acceptance, conservation of the environment, and food quality. The present thesis aims to evaluate the sustainability of conventional (CON), integrated (INT), and organic (ORG) production systems (PS). The assessment of sustainability of different PS was made in terms of the four most significant aspects of sustainability—agronomic, economic, environmental, and food quality—at the field level (i). Agronomic parameters such as the number of leaves, leaf area index, fruit characteristics, and seed/oil yield and economic feasibility were evaluated for oil seed pumpkin (ii). The environmental sustainability was assessed through the ecological footprint and weed biodiversity index (iii). The study of food quality determined the internal quality (total phenol, sugar, organic acid, vitamin C, mineral, and nitrate content and antioxidant activity) and sensory evaluation (iv, v). The sustainability of the PS for the four crops was assessed using a qualitative multi-attribute model (DEXi methodology (vi). Because field trial was conducted in protected landscapes (PL), the options for the development of PLs with the ORG PS were evaluated. To obtain the data, a field trial was conducted on a 4000 m2 area in the years 2008 to 2011. Wheat, oil seed pumpkin, red beet, and cabbage grown by the three different PSs—CON, INT, and ORG—and a control plot were studied. They were arranged in a randomized complete block split-plot design with four replications. The production systems differed in plant protection and fertilization strategies, as defined by legislation and standards. Survey of literature point out that indicator are the basis of assessing sustainability, the assessment of sustainability should encompass at least three pillars of sustainability (i). Agronomic parameters (ii) and economic feasibility were evaluated for oil seed pumpkin in the field trial. The leaf area index differed significantly between CON (4.8 for CON and 4.1 for ORG) and other production systems at later growth stages (BBCH = 600-700), and it was highly correlated with the yield (808 kg ha-1 for CON and 723 kg ha-1 for ORG). The yield and all agronomic parameters were significantly lower in ORG; however, the economic feasibility analysis showed that the financial results could be higher because of lower production costs (1.784 € ha-1 for CON and 1.434.5 € ha-1 for ORG) and higher product prices. The same economic feasibility analysis results were also obtained for cabbage and red beet (iii). The Biodiversity Ecological Footprint index (iii) were interpreted using the SPIonExcel tool and the Shannon-Weaver Diversity Index for the weeds species diversity. The ecological footprint of ORG was 3.3 times lower than that of CON (21 ha to 70 ha), and the Shannon-Weaver diversity index of ORG was significantly higher than that of CON (which was 20% higher, 0.66 for CON and 0.86 for ORG). The internal quality were studied for red beet and white cabbage. Sensory evaluation of sauerkraut samples was made. In the case of red beet, the differences were significant for vitamin C (23.3% higher for ORG than for CON), antioxidant activity (30.3% higher for ORG than for CON), and some microminerals (Na, Cu, Fe, Mn, and Zn) (iv). In the case of cabbage, a significantly lower amount of P and N and a significantly higher amount of Na, Mg, and total phenols (in ORG 0.360 GAE mg g-1 FW and in CON 0.310 GAE mg g-1 FW) was found for ORG than for CON cabbage. The concentration of nitrates is significantly lower in ORG (530 mg kg-1 for CON and 370.37 mg kg-1 for ORG). The sensory evaluation of sauerkraut samples was performed by 100 consumers using a nine-point hedonic scale. The ORG and control samples were evaluated significantly better than the INT and CON samples (overall acceptability was 5.94 for ORG and 5.34 for CON) (v). The core of the qualitative multi-model (DEXi methodology) is a hierarchical tree that divides
Ključne besede: Sustainable agriculture, agronomic parameters, environmental parameters, economic feasibility, food quality, DEX, protected landscapes
Objavljeno v DKUM: 29.11.2012; Ogledov: 2979; Prenosov: 298
.pdf Celotno besedilo (1,79 MB)

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