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Abstract: A comprehensive study of attic dust in an urban area is presented. Its entire life cycle, from determining historical emission sources to recognising the processes that take place in attic dust and its potential to impact human health is discussed. Its chemical composition and morphological characteristics of individual solid particles reflect past anthropogenic activities. High levels of Be-Cd-Cu-Sb-Sn-Pb-Te-Zn and occurrence of Cu-Zn shavings are typical for an industrial zone characterised by a foundry and a battery factory. High levels of Co-Fe-Mo-Ni-W-Ba-Cr-Mg-Mn-Nb-Ti and occurrence of various solid Fe-oxides, particularly spherical particles, were identified in another industrial zone, which was dominated by the automotive and metal-processing industries. Emissions from coal combustion affected the distribution of S-Se-Hg-Tl-As-Ag-U. The predominant mineral in attic dust is gypsum, which was presumably formed in situ by the reaction of carbonate dust particles and atmospheric SO2 gas. The high oral bioaccessibility of As-Cd-Cu-Pb-Zn in the gastric phase and high bioaccessibility of As-Cu-Cd-Ni in the gastrointestinal phase were identified. Determined characteristics of attic dust and identified possibilities of prolonged human exposure to it indicate that attic dust should be treated as an excellent proxy for historical air contamination as well as a potentially hazardous material for human health.
Keywords: multi-element composition, scanning electron microscopy, oral bioaccessibility, unified BARGE method, urban geochemistry
Published in DiRROS: 23.06.2022; Views: 675; Downloads: 245
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Abstract: Biomass derived from small-diameter, dense, thinning stands is largely underutilized within the European Union, mainly because of in-effective harvesting methods and cutting technology, leading to high supply costs. Therefore, the efficacy of boom-corridor thinning (BCT) and selective thinning (ST) on harvester felling and bunching productivity was compared for the first thinning of whole tree biomass in small-diameter, dense stands. BCT working method is when trees are cut with linear movements of the harvester’s boom reach, along narrow corridors, instead of cutting each tree selectively (ST). Trials were performed in six forest stands, one in Sweden, two in Finland, and three in Slovenia, using the same harvester and operator. A time-and-motion study was carried out in 64 pre-marked study units (32 replications per method), across a variety of stand conditions. The biomass removal for both treatments averaged 40.2 dry t ha -1 and BCT productivity averaged 5.4 dry t PMh -1. For BCT, harvester work time consumption (sec tree -1) and productivity (dry t PMh -1) were on average 27% lower and 16% higher, respectively, compared with ST. The effectiveness of the accumulating felling head technology used could potentially be increased by implementing a feed-roller system when handling excessive tree lengths. Developing dedicated harvesting technology for BCT could further boost productivity, facilitating cost-effective and sustainable utilization of low-value small-diameter tree biomass and replacing fossil resources.
Keywords: bioenergy, accumulating felling head, multi-tree handling, silviculture, bioeconomy, forestry
Published in DiRROS: 20.04.2022; Views: 640; Downloads: 431
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Keywords: quartz crystal microbalance, mAb, in-line sensor, protein A, continuous multi-column affinity chromatography
Published in DiRROS: 01.09.2020; Views: 1629; Downloads: 1110
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Abstract: Quality information is crucial for planning and running of production in wood industry companies. Information of crucial importance is the following: quality in the production process according to work orders and types of product, the information on the missing materials i.e. constituent parts according to projects i.e. work orders and the information on launching work orders into production. The method of multi-criteria decision-making was used for determining the order of launching group products into production. We studied three main criteria: market factors, organisation-production factors and economic factors. For computer support, we chose the computer programme DEXi, which represents the framework of the expert system for multi-criteria decision-making.
Keywords: wood enterprise, work orders, organization, multi-criteria decision-making method
Published in DiRROS: 12.07.2017; Views: 4482; Downloads: 1962
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