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11.
Justin Salminen Peter Blomberg Jarno Mäkinen Lea Räsänen 《American Institute of Chemical Engineers》2015,61(9):2739-2748
Mining and metals processing are not invisible activities and are heavy industries, which require energy, water, chemicals, and land area. Recently more emphasis is given to environmental and societal aspects in mining and processing. Development of good practices with improved resource efficiency, new recovery methods and sustainability thinking are increasingly required. This work shows pH titration method for acid mine drainage (AMD) water incorporated with aqueous thermodynamic model for selective metals precipitation from complex solution. Also two examples on gold recovery methods from aqueous streams are shown: biosorption using fungal matter and solvent extraction using a task‐specific ionic liquid. By understanding chemical thermodynamics and natural phenomena, there is a better chance of developing solutions for environmental problems and new industrial processes. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2739–2748, 2015 相似文献
12.
Laura Lehtola Marjo Kauppinen Jarno Vähäniitty Marko Komssi 《Requirements Engineering》2009,14(2):113-128
A strong link between strategy and product development is important, since companies need to select requirements for forthcoming
releases. However, in practice, connecting requirements engineering (RE) and business planning is far from trivial. This paper
describes the lessons learned from four software product companies that have recognized the need for more business-oriented
long-term planning. The study was conducted using the action research approach. We identified five practices that seem to
strengthen the link between business decisions and RE. These are (1) explicating the planning levels and time horizons; (2)
separating the planning of products’ business goals from R&D resource allocation; (3) planning open-endedly with a pre-defined
rhythm; (4) emphasizing whole-product thinking; and (5) making solution planning visible. To support whole-product thinking
and solution planning, we suggest that companies create solution concepts. The purpose of the solution concept is to provide
a big picture of the solution and guide RE activities. 相似文献
13.
Outi Sipil A. Visa O. Salonen T. Erkinjuntti T. Katila 《Pattern recognition letters》2001,22(14):1475-1482
Automatic intensity-based tissue classification sets requirements for the quality of multispectral magnetic resonance (MR) images. Tests for evaluating the separability of tissue classes, and on the other hand class distances required to obtain reliable classification, are presented in this study. Intraslice, interslice and interpatient training schemes for 5-nn classification were considered. Interslice training was utilized in classification of images from 10 patients with ischemic stroke giving results of satisfactory but highly variable quality. Based on the experience with these data sets, similar tests are recommended before imaging a large patient series in order to avoid extra manual work and to obtain reliable classification results. 相似文献
14.
15.
Muikku M Rahola T Pusa S Salonen L Wahl W Roth P Haninger T Kucheida D 《Radiation protection dosimetry》2003,105(1-4):615-618
In a preliminary study, in vivo skull measurements and in vitro urine measurements of 210Pb and nulU have been performed to find out the individual, chronic exposure to waterborne natural radionuclides of a small group of Finnish people. For their domestic water, the studied individuals use water from drilled wells containing elevated concentrations of natural uranium and its daughter nuclides ((234,235,238)U, 222Rn, (226,228)Ra, 210Po, 210Pb). Enhanced 210Pb and 235U activities were observed in several people. A positive correlation is observed between the U concentration in urine (microg d(-1)) and the number of counts (cpm) in the gamma ray energy peaks originating from the decay of 235U and 234Th respectively. Calibration of the detector set-up and the determination of background sources are in progress. 相似文献
16.
A compact varactor-tuned meander line monopole antenna for DVB-H signal reception is presented. The operating frequency of the antenna is continuously tuned over the frequency range of the DVB-H standard 470-702 MHz. The antenna has an omnidirectional radiation pattern and covers the frequency range with requisite impedance bandwidth and gain level. The antenna element occupies a very small volume (0.7 cm3 ) and can be used in 40 x 100 x 10 mm devices. 相似文献
17.
K. Nordlund E. Salonen J. Keinonen C. H. Wu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2001,180(1-4):77-84
While the physical sputtering of atoms caused by keV and MeV ions has been studied extensively both by molecular dynamics (MD) simulation and experiments, the mechanisms leading to atom and molecule erosion at energies 1–100 eV are not very well understood. We now describe how low-energy hydrogen ions can cause erosion of carbon atoms and hydrocarbon molecules by entering the region of a carbon–carbon chemical bond and hence breaking it, a process we call ‘swift chemical sputtering'. In the particular case of hydrogen bombardment of carbon-based materials, we further show that this can lead to erosion yields far exceeding those expected for a physical sputtering process. 相似文献
18.
The uranium concentrations in Finnish drilled wells may reach a few mg l-
1 (maximum 12.4 mg l-
1). Most of the highest concentrations of uranium have been found in Southern Finland but elevated concentrations have been found all over the country. The removal of uranium with a strongly basic anion-exchange resin (SBA) has been tested in domestic use with different types of ion-exchange filters and water. SBA resin was considered to be the best type of resin for testing because of its high capacity, simplicity, and cost efficiency. Uranium is removed with SBA resin to more than 90% irrespective of the test location, water quality, and the presence of competing ions. 相似文献
19.
Van De Kamp M.M.J.L. Riva C. Tervonen J.K. Salonen E.T. 《Antennas and Propagation, IEEE Transactions on》1999,47(1):77-85
In the prediction models of tropospheric scintillation on Earth-satellite paths from Karasawa, Yamada, and Allnutt and ITU-R, the frequency dependence of scintillation is expressed as a power law with a different exponent for each model. This is verified using a collection of measurement results from different satellite links in Europe, the US, and Japan at frequencies from 4 to 50 GHz and elevation angles from 2.5 to 52°. It shows that the exponent of the power law varies widely among the results from the different sites. Possible explanations of this are: (1) the frequency dependence of scintillation due to cloudy turbulence is different from that due to clear-sky turbulence and this kind of scintillation may be present to different extents in the various databases due to climatic differences and different clear-sky selection procedures or (2) angle-of-arrival fluctuations due to turbulence have a different frequency dependence and this effect may have some impact on the measured scintillation at some of the sites 相似文献
20.
SA Everson DE Goldberg GA Kaplan J Julkunen JT Salonen 《Canadian Metallurgical Quarterly》1998,60(6):730-735
OBJECTIVE: To determine the incidence and prevalence of multiple sclerosis in the Lothian and Border Health Board Regions of south east Scotland. METHODS: Incidence study: all patients were identified in whom a diagnosis of Poser category probable or definite multiple sclerosis was made by a neurologist between 1992 and 1995. Prevalence study: all patients known to have multiple sclerosis who were alive and resident in the study area on 15 March 1995 were recorded. RESULTS: The crude annual incidence rates of probable or definite multiple sclerosis per 100000 population were the highest ever reported: 12.2 (95% confidence interval (95% CI) 10.8-13.7) in the Lothian Region and 10.1 (95% CI 6.6-13.6) in the Border Region. A total of 1613 patients with multiple sclerosis were resident in the study area, giving standardised prevalence rates per 100000 population of 203 (95% CI 192-214) in the Lothian Region and 219 (95% CI 191-251) in the Border Region. Prevalent cases were more likely than expected to have a Scottish surname (risk ratio 1.24, 95% CI 1.14-1.34). CONCLUSION: Orkney and Shetland were previously thought to have by far the highest prevalence of multiple sclerosis in the world: about double that found in England and Wales. However, the prevalence in south east Scotland is equally high, suggesting that the Scottish population as a whole has a genetic susceptibility to the disease, and undermining the hypothesis that patterns of infection specific to small sparsely populated island communities are important in the causation of multiple sclerosis. 相似文献