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11.
The paper considers the use of mixed methods in international business research by reviewing empirical studies in four major journals. A total of 484 articles were reviewed, 68 of which had applied a mixed method strategy. In our analysis we categorize mixed methods according to their use in different stages of the research process and provide a range of alternative designs for mixing qualitative and quantitative methods. 相似文献
12.
Occurrence of pharmaceuticals in river water and their elimination in a pilot-scale drinking water treatment plant 总被引:10,自引:0,他引:10
The occurrence of four beta blockers, one antiepileptic drug, one lipid regulator, four anti-inflammatories, and three fluoroquinolones was studied in a river receiving sewage effluents. All compounds but two of the fluoroquinolones were observed in the water above their limit of quantification concentrations. The highest concentrations (up to 107 ng L(-1)) of the compounds were measured during the winter months. The river water was passed to a pilot-scale drinking water treatment plant, and the elimination of the pharmaceuticals was followed during the treatment. The processes applied by the plant consisted of ferric salt coagulation, rapid sand filtration, ozonation, two-stage granular activated carbon filtration (GAC), and UV disinfection. Following the coagulation, sedimentation, and rapid sand filtration, the studied pharmaceuticals were found to be eliminated only by an average of 13%. An efficient elimination was found to take place during ozonation at an ozone dose of about 1 mg L(-1) (i.e., 0.2-0.4 mg of O3/ mg of TOC). Following this treatment, the concentrations of the pharmaceuticals dropped to below the quantification limits with the exception of ciprofloxacin. Atenolol, sotalol, and ciprofloxacin, the most hydrophilic of the studied pharmaceuticals, were not fully eliminated during the GAC filtrations. All in all, the treatment train was found to very effectively eliminate the pharmaceuticals from the rawwater. The only compound that was found to pass almost unaffected through all the treatment steps was ciprofloxacin. 相似文献
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In this study, we investigated the influence of the difference in the chemical structures of hyaluronic acid (HA), sodium hyaluronate (Na-HA), and starch water-soluble polysaccharides and the difference in sample shape (as-received samples and membranes) on water vapor solubility. The sorption at this time was characterized by a Fickian diffusion increase at one stage, but HA and starch had a non-Fickian diffusion increase at the two stages in the high humidity region of 52% or more. In addition, all sorption isotherms of HA, Na-HA, and starch did not depend on the sample shape and had an extended dual-mode sorption type behavior consisting of Flory–Huggins and dual-mode sorption types. Furthermore, the infinite dilution solubility coefficient for water molecules increased with increasing surface free energy and correlates with the surface free energy obtained from the contact angle of water of HA, Na-HA, and starch membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48223. 相似文献
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Niina MM Saviranta Riitta Julkunen‐Tiitto Elina Oksanen Reijo O Karjalainen 《Journal of the science of food and agriculture》2010,90(3):418-423
BACKGROUND: Phenolic compounds have recently received considerable attention for their ability to protect plant and human cells from oxidative stress‐induced damage. Red clover (Trifolium pratense L.) is a rich source of isoflavonoids with multiple potential protective functions. The aim of this study was to identify and characterise phenolic compounds in red clover roots by high‐performance liquid chromatography and mass spectrometry and to study the effects of stress factors and growth stage on root phenolics. RESULTS: A total of 28 phenolic compounds were tentatively identified in red clover roots. The most abundant phenolics in pot‐grown roots were formononetin glycoside malonate (G‐M) (1.51–4.26 mg g?1), formononetin (2.21–3.57 mg g?1) and biochanin A (1.73–2.17 mg g?1), whereas field‐grown roots were rich in formononetin‐G‐M (3.90–4.27 mg g?1), maackiain‐G‐M (2.35–3.02 mg g?1) and pseudobaptigenin‐G‐M (1.80–2.58 mg g?1). Concentrations were affected by the growth stage. Ozone exposure slightly affected the total phenolic content in roots and also had minor effects on individual compounds. CONCLUSION: Elevated ozone, cultivation regime and growth stage affected the levels of phenolics in red clover roots, suggesting sensitivity of root phenolics to biotic and abiotic stress conditions. The high levels of phenolics found in roots even in late autumn may be utilised in many applications. Copyright © 2009 Society of Chemical Industry 相似文献
17.
Niina Mallat Matti Rossi Virpi Kristiina Tuunainen Anssi Öörni 《Personal and Ubiquitous Computing》2008,12(1):57-65
In this paper, we present results from a study of mobile ticketing service adoption in public transportation. The theoretical
background of the study is based on technology adoption and trust theories, which are augmented with concepts of mobile use
context and mobility. Our empirical findings from analyses of a survey data suggest that compatibility of the mobile ticketing
service with consumer behavior is a major determinant of adoption. Mobility and contextual factors, including budget constraints,
availability of other alternatives, and time pressure in the service use situation were also found to have a strong effect
on the adoption decision. Our findings suggest that contextual and mobile service-specific features are important determinants
of mobile service adoption and should thus be integrated into the traditional adoption models. 相似文献
18.
Timo?JokelaEmail author Jussi?Koivumaa Jani?Pirkola Petri?Salminen Niina?Kantola 《Personal and Ubiquitous Computing》2006,10(6):345-355
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed.
相似文献
Timo Jokela (Corresponding author)Email: |
Jussi KoivumaaEmail: |
Jani PirkolaEmail: |
Petri SalminenEmail: |
Niina KantolaEmail: |
19.
Seasonal variation in the occurrence of pharmaceuticals in effluents from a sewage treatment plant and in the recipient water 总被引:6,自引:0,他引:6
The occurrence of five pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac, and bezafibrate) in the influent and effluent water of a sewage treatment plant (STP) in the recipient river water and in a drinking water treatment plant (DWTP) located downstream from the STP was followed during three seasons: winter, spring, and summer. In the STP, the elimination of the pharmaceuticals decreased significantly (an average of 25% compared to spring and summer) in wintertime leading to increased concentrations of pharmaceuticals in the effluent water. The total concentration of all the studied pharmaceuticals in the effluent water was 3-5 times higher in wintertime (about 2500 ng L(-1)) than during the other seasons (about 500-900 ng L(-1)). Accordingly, the highest concentrations (up to 129 ng L(-1)) in the recipient river were measured in the wintertime. Pharmaceuticals were carried longer distances downstream from the STP when the river was covered by ice and snow. During a drastic increase in water flow rate (i.e., during snowmelting), a fast transportation of the pharmaceuticals was observed. The DWTP located downstream from the STP produced water that contained about 8 ng L(-1) of ibuprofen and ketoprofen in the winter sample, whereas in spring and summer the studied pharmaceuticals could not be detected in the drinking water. The results show that cold seasons in boreal areas can severely increase the environmental risk of pharmaceuticals and the risk for contamination of drinking water. 相似文献
20.
Niina T. Yamaguchi T. Yodoshi K. Yagi K. Hamada H. 《Quantum Electronics, IEEE Journal of》1983,19(6):1021-1025
A GaAlAs visible laser with a novel structure, called a buried-cap planar (BCP) stripe laser, has been developed. It has an epitaxial ZnSe semiinsulating layer grown by molecular beam epitaxy (MBE) on a cladding layer, leaving a narrow stripe for the current confinement. In this laser a reflective index waveguide is constructed by using a channeled substrate, and the current flow is confined by growing the semi-insulating ZnSe single crystal on the cladding layer after mesa etching the cap layer. There are many advantages in this structure: the diffusion process is not necessary, the current confinement is complete, and the thermal strains and misfit dislocations can be avoided. These advantages assure a highly reliable device performance, and a high-yield fabrication process. 相似文献