Effects of thermal oxidation conditions of silicon electrodes on cathodic electrochemiluminescence of Ru(bpy)3 chelate

Hot electrons emitted from thin oxide film-coated heavily doped silicon electrodes by cathodic pulse polarization can induce electrochemiluminescence from luminophores. The intensity of electrochemiluminescence produced at the electrode surface is dependent on the features of thin oxide films formed by thermal oxidation. As a preliminary study, we investigated the effect of thermal oxide growth conditions on the intensity of electrochemiluminescence produced at these electrodes, such as oxidation atmospheres, oxidation temperature, oxidation time and pre-treatment of wafers, using ruthenium(II) tris-(2,2′-bipyridine) chelate as a model luminophore. Optimal oxidation conditions of heavily doped silicon electrodes were obtained for the generation of intense electrochemiluminescence at this kind of silicon electrodes.     

The use of mobile technology for online shopping and entertainment among older adults in Finland

Older adults are becoming an important market segment for all internet-based services, but few studies to date have considered older adults as online shoppers and users of entertainment media. Utilising the concept of life course, this article investigates the use of mobile technologies for online shopping and entertainment among consumers aged 55 to 74. The data were collected with a web-based survey completed by a panel of respondents representing Finnish television viewers (N = 322). The results reveal that consumers aged 55 to 74 use a smartphone or tablet to purchase products or services online as often as younger consumers. In contrast, listening to internet radio and watching videos or programmes online with a smartphone or tablet are most typical for younger male consumers. The results demonstrate that mobile-based online shopping is best predicted by age, higher education, and household type (children living at home), and use of entertainment media by age and gender.     

Microstructure and Porosity of Laser Welds in Cast Ti-6Al-4V with Addition of Boron

Metallurgical and Materials Transactions A - Addition of small amounts of boron to cast Ti-6Al-4V alloy has shown to render a finer microstructure and improved mechanical properties. For such an...     

Heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence of a rhodamine label at oxide-coated aluminum and silicon electrodes

This paper describes a heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence (HECL) of a rhodamine label. Thin oxide-film coated aluminum and silicon electrodes were modified with an aminosilane layer and derivatized with short, 15-mer oligonucleotides via diisothiocyanate coupling. Target oligonucleotides were conjugated with tetramethylrhodamine (TAMRA) dye at their amino modified 5′ end and hybridization was detected using HECL of TAMRA. Preliminary results indicate sensitivity down to picomolar level and low nonspecific adsorption. The sensitivity was better on oxide-coated silicon compared to oxide-coated aluminum electrodes and two-base pair mismatched hybrids were successfully discriminated. The experimental results presented here might be useful for the design of disposable electrochemiluminescent DNA biosensors.     

Design of Mobile Phones for Older Adults: An Empirical Analysis of Design Guidelines and Checklists for Feature Phones and Smartphones

Design guidelines and checklists are suggested as a useful tool in the development and evaluation of interface design of mobile phones for older adults. Given the intense evolution of mobile phone design, understanding how the design guidelines and checklists have taken into account the advances in mobile phone usability for older adults is important for their correct application and future development. Thus, this study explores the usability dimensions of mobile phone design for older adults and the related changes in terms of time and the type of device (feature phones vs. smartphones) based on an expert coding of the eight mobile phone design guidelines and checklists for older adults published between 2006 and 2014. The results of the expert coding show that design guidelines and checklists most frequently deal with visual and haptic issues (e.g., high contrast, button type, and button size), whilst they hardly ever address various elements of textual interface (e.g., ease of text entry, a button’s feedback, and font type). Over time, the design guidelines and checklists have become more complex in terms of the average number of included usability categories and dimensions. For smartphones, the guidelines, on average, put more emphasis on the screen, touchscreen, text, and exterior related issues, whereas the design guidelines for feature phones stress the usability of the keypad and menus. Besides revealing potential usability dimensions that could be further expanded in the guidelines, this study also highlights the need for research that would empirically validate the design guidelines and checklists in the future.     

The insufficiency of Pigouvian taxes in a spatial general equilibrium model

The paper considers, in a spatial general equilibrium setting, the pollution externality problem caused by a competitive industry. It is shown that the pollution control instrument supporting the optimum is a two-part Pigouvian tax–emission rights scheme in which the polluter pays only for the emissions which exceed its initial emission rights. The optimal level of the emission rights depends on the nature of pollution. In the global pollution case they are zero, whereas in the local pollution case they are equal to the firm's emissions at the optimum. In general, the optimal initial emission rights are between these values, but they may also be negative. In the latter case the firm pays for a greater amount of emissions than it emits. The emission tax proceeds, if there are any, must be distributed to the victims (households) as compensation. Received: December 1998/Accepted: May 2000     

Progress in Laboratory Automation at Akita University Hospital

Akita University Hospital was established in 1971. Since then, we have been introducing automated analysis systems to deal with rapidly increasing tasks and demand in the clinical laboratory. In 1988, in collaboration with Hitachi Ltd. (Tokyo, Japan), we developed an automated analysis system composed of an automatic serum separating-aliquoting system connected to analysis systems through an automatic transport system. In 1998, the systems were integrated, enabling 97.6% of samples to be analyzed automatically. With this integrated system, information including the name of the patient, code number, age, gender, department, test to be performed and so on are all encoded on the label of the sampling tubes which are automatically labeled and sorted at the sampling division. The laboratory automation system succeeded in saving labor and time, yet there are still some areas that need improving. Namely, 1) minimizing the quantity of the sample required for analysis, 2) speeding up of the transportation, and 3) down-sizing the system. The development of less invasive, more compact and speedier analysis systems will make the clinical laboratory mobile or portable in the near future and will expand the working field of the clinical laboratory to remote areas and home-nursing services in the community.     

Trends in hydrometeorological conditions and stream water organic carbon in boreal forested catchments

Temporal trends in stream water total organic carbon (TOC) concentration and export were studied in 8 forested headwater catchments situated in eastern Finland. The Seasonal Kendall test was conducted to identify the trends and a mixed model regression analysis was used to describe how catchment characteristics and hydrometeorological variables (e.g. precipitation, air and stream water temperatures, and atmospheric deposition) related to the variation in the concentration and export of stream water TOC. The 8 catchments varied in size from 29 to 494 ha and in the proportion of peatland they contained, from 8 to 70%. Runoff and TOC concentration were monitored for 15-29 years (1979-2006). Trends and variation in TOC levels were analysed from annual and seasonal time series. Mean annual TOC concentration increased significantly in seven of the eight catchments. The trends were the strongest in spring and most apparent during the last decade of the study period. The slopes of the trends were generally smaller than the variation in TOC concentration between years and seasons and between catchments. The annual TOC export showed no clear trends and values were largely determined by the temporal variability in runoff. Annual runoff showed a decreasing trend in two of the eight catchments. Mean annual air and stream water temperatures showed increasing trends, most clearly seen in the summer and autumn series. According to our modeling results, stream water temperature, precipitation and peatland percentage were the most important variables explaining annual and most seasonal TOC concentrations. The atmospheric deposition of SO₄, NH₄, and NO₃ decreased significantly over the study period, but no significant link with TOC concentration was found. Precipitation was the main hydrometeorological driver of the TOC export. We concluded that stream water TOC concentrations and exports are mainly driven by catchment characteristics and hydrometeorological factors rather than trends in atmospheric acid deposition.