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141.
Ceyla Güngör Hasan Serin Selahattin Serin Kadir Aydın 《International Journal of Green Energy》2015,12(1):98-105
The overall objective of this study was to explore the utility of waste plastics as a potential source of diesel fuel. An experimental study was conducted to evaluate the use of various blends of plastic oil produced from waste polyethylene (WPE) with diesel fuel (D). WPE was degraded thermally and catalytically using sodium aluminum silicate as a catalyst. The oil collected at optimum conditions (414°C–480°C range and 1 h reaction time) was fractionated at different temperatures and fuel properties of the fractions were measured. Plastic oil was blended with diesel fuel at the volumetric ratios of 5%, 10%, 15%, 20%, and 100%. Fuel properties of blends are found comparable with those of diesel fuel within the EN 590 Diesel Fuel standard and they can also be used as fuel in compression ignition engines without any modification. Engine performance and exhaust emission studies of 5% WPE-D (WPE5) blend were performed. Experimental results showed that carbon monoxide (CO) emission is decreased by 20.63%, carbon dioxide (CO2) emission is increased by 3.34%, and oxides of nitrogen (NOx) emission is increased by 9.17% with WPE-D (WPE5) blend compared to diesel fuel. 相似文献
142.
Magalie Bassan Doulaye Koné Mbaye Mbéguéré Christof Holliger Linda Strande 《Journal of Environmental Planning and Management》2015,58(10):1690-1710
Many factors influence success and failure of large-scale faecal sludge and wastewater treatment projects in low-income countries. Benchmarking indicators and multicriteria analysis were adapted to define key institutional, technical and financial factors, to analyse their interrelations, and understand priorities to consider when planning and managing treatment plants. For the first time, these methods have been combined in a quantitative manner to assess planned and on-going treatment plant projects. This new methodology will aid sanitation utilities, private consultants, and funding institutions to prioritise activities and organise the operation of treatment plants. 相似文献
143.
Intensive manure application is an important source of diffuse phosphorus (P) pollution. Phosphorus availability from animal manure is influenced by its chemical speciation. The major objective of this study was to investigate the P speciation in raw and anaerobically digested dairy manure with an emphasis on the calcium (Ca) and magnesium (Mg) phosphate phases. Influent and effluent from an on-farm digester in Wisconsin were sampled and sieved, and the 25 to 53 microm size fraction was dried for X-ray powder diffraction (XRD) and P K-edge X-ray absorption near edge structure (XANES) analyses. Struvite (MgNH4PO4.6H2O) was identified in both the raw (influent) and anaerobically digested (effluent) manure using XRD. Qualitative analysis of P K-edge XANES spectra indicated that the Ca orthophosphate phases, except dicalcium phosphate anhydrous (DCPA) or monetite (CaHPO4), were not abundant in dairy manure. Linear combination fitting (LCF) of the P standard compounds showed that 57.0 and 43.0% of P was associated with DCPA and struvite, respectively, in the raw manure. In the anaerobically digested sample, 78.2% of P was present as struvite and 21.8% of P was associated with hydroxylapatite (HAp). The P speciation shifted toward Mg orthophosphates and least soluble Ca orthophosphates following anaerobic digestion. Similarity between the aqueous orthophosphate (aq-PO4), newberyite (MgHPO4.3H2O), and struvite spectra can cause inaccurate P speciation determination when dairy manure is analyzed solely using P K-edge XANES spectroscopy; however, XANES can be used in conjunction with XRD to quantify the distribution of inorganic P species in animal manure. 相似文献
144.
Yusuf Yavuz Reza Shahbazi A. Savaş Koparal Ülker Bakır Öğütveren 《Environmental science and pollution research international》2014,21(14):8603-8609
The aim of this study is the treatment of Basic Red 29 (BR29) dye solution using hybrid iron-aluminum electrodes by electrocoagulation and electro-Fenton methods. The effect of current density, initial pH, supporting electrolyte, H2O2, and initial dye concentration on dye removal efficiency was investigated, and the best experimental conditions were obtained. Time-coarse variation of UV-Vis spectra and toxicity and chemical oxygen demand (COD) removal were also examined at the best experimental conditions. Both systems were found very successful for the removal of BR29 dye. The removal efficiency of >95 % for BR29 dye solution was reached easily in a short time. At the best experimental conditions, for the initial BR29 concentration of 100 mg/L, >95 % BR29 dye and 71.43 % COD removal were obtained after 20 and 40 min of electrolysis, respectively. Additionally, toxicity results for electro-Fenton treatment of 100 mg/L BR29 were also very promising. According to the results obtained, although electro-Fenton is more effective, both systems can be used successfully to treat textile wastewater including dyes. 相似文献
145.
Tanja Schlaikjær Hartwig Louise Ambye Steen Sørensen Finn Stener Jørgensen 《黑龙江环境通报》2017,37(6):527-539
With a high sensitivity and specificity, non-invasive prenatal testing (NIPT) is an incomparable screening test for fetal aneuploidy. However, the method is rather newly introduced, and experiences with discordant results are few. We did a systematic review of literature reporting details of false positive and false negative NIPT results. Discordant sex chromosome results were not included. We identified 22 studies reporting case details. In total, 206 discordant cases were included, of which 88% were false positive and 12% false negative. Details on maternal age, gestational age, platform/company, Z-score, fetal fraction, results and explanation were specified. The main reasons for discordant results were confined placental mosaicism, maternal copy number variation, vanished twin, maternal cancer and true fetal mosaicism. A very high percentage of cases (67%) were reported with no obvious biological or technical explanation for the discordant result. The included cases represent only a minor part of the true number of false positive or false negative NIPT cases identified in fetal medicine clinics around the world. To ensure knowledge exchange and transparency of NIPT between laboratories, we suggest a systematic recording of discordant NIPT results, as well as a quality assurance by external quality control and accreditation. © 2017 John Wiley & Sons, Ltd. 相似文献
146.
Delphine Nicolas Aurélie Chaalali Hilaire Drouineau Jérémy Lobry Ainhize Uriarte Angel Borja Philippe Boët 《Regional Environmental Change》2011,11(3):639-649
The aim of this study was to determine whether the latitudinal distribution of fish species that use estuaries to complete
their entire life cycle has shifted northward as an expected consequence of global warming. The mean latitude of past fish
species distributions found in 1970s’ literature was compared with the mean latitude of distributions today based on fish
density indices collected in 55 tidal estuaries along the Atlantic European seaboard, from Portugal to Scotland. Among the
15 most common species, 11 displayed a positive difference between current and past mean latitudes suggesting a northward
shift of the populations. Using the occurrence of subtropical species in temperate areas as an indicator of water warming,
the northernmost range limit of 10 subtropical species was subsequently focused on. Six of them were recorded up to their
past northern latitudinal limit. These results reinforced the idea that a number of fish species associated to estuaries have
migrated northwards over the last 30 years, possibly due to water warming. These ecological changes can get important managerial
implications, i.e. in the assessment of the ecological status in European directives. 相似文献
147.
148.
This study developed a comprehensive framework to incorporate landscape ecological principles into the landscape planning and design process, with a focus on the design of new patches in the rural landscape. The framework includes two interrelated phases: patch analyst (PA) and patch designer (PD). The patch analyst augments the process of landscape inventory and analysis. It distinguishes nodes (associated with potential habitat patches) from links (associated with corridors and stepping stones between habitats). For natural vegetation patches, characteristics such as size, shape, and spatial arrangement have been used to develop analytical tools that distinguish between nodes and links. The patch designer uses quantitative information and analytical tools to recommend locations, shapes, sizes, and composition of introduced patches. The framework has been applied to the development of a new golf course in the rural Mediterranean landscape of Apulia, Southern Italy. Fifty new patches of Mediterranean maquis (24 patches) and garrigue (26 patches) have been designed and located in the golf course, raising the overall natural vegetation area to 70 ha (60% of total property). The framework has potential for use in a wide variety of landscape planning, design, and management projects. 相似文献
149.
Juhani Smolander Kalev Kuklane Désirée Gavhed H?kan Nilsson Ingvar Holmér 《International journal of occupational safety and ergonomics》2004,10(2):111-117
The aim of the study was to examine the effects of wearing an ice-vest (ca 1 kg) on physiological and subjective responses in fire fighters. The experiments were carried out on a treadmill in a hot-dry environment. The physical cooling effect of the ice-vest was measured with a thermal manikin. The ice-vest effectively reduced skin temperatures under the vest. On average, heart rate was 10 beats/min lower, the amount of sweating was reduced by 13%, and subjective sensations of effort and warmth were lower during work with the ice-vest compared to work without it. Thermal manikin tests indicated that the useful energy available from the vest for body cooling was rather high (58%). In conclusion, the ice-vest reduces physiological and subjective strain responses during heavy work in the heat, and may promote efficient work time by 10%. 相似文献
150.
R.?A.?HillEmail author L.?Barrett D.?Gaynor T.?Weingrill P.?Dixon H.?Payne S.?P.?Henzi 《Behavioral ecology and sociobiology》2003,53(5):278-286
Annual cycles in day length are an important consideration in any analysis of seasonal behaviour patterns, since they determine the period within which obligate diurnal or nocturnal animals must conduct all of their essential activities. As a consequence, seasonal variation in day length may represent an ecological constraint on behaviour, since short winter days restrict the length of the time available for foraging in diurnal species (with long summer days, and thus short nights, a potential constraint for nocturnal species). This paper examines monthly variation in activity patterns over a 4-year study of chacma baboons (Papio cynocephalus ursinus) at De Hoop Nature Reserve, South Africa. Time spent feeding, moving, grooming and resting are all significant positive functions of day length, even before chance events such as disease epidemics and climatically mediated home range shifts have been accounted for. These results provide strong support for the idea that day length acts as an ecological constraint by limiting the number of daylight hours and thus restricting the active period at certain times of year. Day length variation also has important implications across populations. Interpopulation variation in resting time, and non-foraging activity in general, is a positive function of latitude, with long summer days at temperate latitudes apparently producing an excess of time that cannot profitably be devoted to additional foraging or social activity. However, it is the short winter days that are probably of greatest importance, since diurnal animals must still fulfil their foraging requirements despite the restricted number of daylight hours and elevated thermoregulatory requirements at this time of year. Ultimately this serves to restrict the maximum ecologically tolerable group sizes of baboon populations with increasing distance from the equator. Seasonal variation in day length is thus an important ecological constraint on animal behaviour that has important implications both within and between populations, and future studies at non-equatorial latitudes must clearly be mindful of its importance. 相似文献