Layered dielectric–magnetic composite structures for Rf-applications

In this paper multilayer magnetic–dielectric composite structures for high frequency applications are introduced. The 0–3 type dielectric and magnetic composites with homogeneously distributed ceramic inclusions were fabricated by mixing extrusion and injection moulding. Magnetic Yttrium Iron Garnet (YIG) and Z-type Hexaferrite (HexaZ) as well as paraelectric Barium Strontium Titanate (BST) powders were used to enhance the permittivity and permeability of the composites. The magnetic–dielectric multilayer composites were constructed by hot-laminating magnetic and dielectric layers in turn to create a solid 2-2 type composite structure. The microstructure, high frequency dielectric and magnetic properties of individual layers and 2-2 composites were investigated and measured. The measurement results indicate that such multimaterial multilayer structures are good candidates for components with reduced dielectric and magnetic losses. Moreover, the observed good frequency stability and the cut-off frequencies above 1 GHz suggested that the composites could be utilized in, e.g., sophisticated functional circuit boards and RF devices.     

The effect of positive feedback on industrial housekeeping and accidents; A long-term study at a shipyard

The experiments aimed to determine the effects of performance feedback on housekeeping behavior and consequently, on injuries over a longer period of time, and also to assess the validity of well-known Heinrich's axioms with respect to accident causation. The study was conducted at two production halls of a shipyard. Nine performance targets were set for housekeeping performance. An observation method was developed to measure performance. After we determined the baseline, feedback on performance was given by posting the results of each observation round as a large graph on the wall. The housekeeping index was significantly improved in both halls after the feedback was started. The effect persisted throughout the two-year follow-up period. Accidents were reduced by 70–90%, much more than expected merely on the basis of improved housekeeping. The effect of feedback on accidents persisted for the three-year follow-up period. The possible mechanisms are discussed.     

Assessment of Social Services’ Disaster Risk Management: Case Finland

Local actors are crucial in disaster risk management; thus, their capacities should be assessed periodically. In this study, local social services’ preparedness plans were assessed using Emergency Management Program Measurement and quantitative document analysis. The specific aim was to study how social service areas of various sizes were prepared for disasters in Finland. The results showed that disaster risk management capacity varied significantly between large and small service areas. Larger areas were better prepared for supporting management, and had better procedures to activate their response, modern public information and deeper cooperation with the private sector and the civil society. The differences might derive from the fact that large areas have more resources allocated to disaster risk management.     

Future Directions for Mobile Communications Business,Technology and Research

This paper presents a picture of the mobile communications market and expected further development of systems and technologies. This is done with evaluating the market needs and reflecting these to available technology as well as technological opportunities. Despite of apparently advanced state of the technology and business, both market and technical solutions are concluded to likely experience further radical changes. The need for wireless capacity is two orders of magnitude more than what combined 2G and 3G would provide. A meaningful research objective to achieve is not in any single topic but will emerge from combining the needs of market and society with the opportunities offered by plurality of technologies. This opportunity starts form explorations aiming to a deeper understanding of the spatial propagation effects and ways to deploy them.     

Heat and Mass Transfer Analogy Studies of Binary Liquid Mixture in Comparison with Eteanol-n-Heptane Evaporating to Air

ABSTRACT

An expenmental and theoretical study of heat and mass transfer analogy and a comparison of that to a binary liquid mixture evaporation is presented. Common organic solvents, ethanol and n-heptane, were used to form an alcohol - hydrocarbon mixture. Studies were carried out in a horizontal rectangular channel having air flow velocities of 0.2 – 0.9 m/s. Heat transfer coefficients were measured with a copper plate resistor and mass transfer coefficients with a square pool. The heat and mass transfer analogy is presented for a system having two evaporating compounds with a fixed value of air flow and verified by measuring and comparing mass transfer coefficients for distilled water with air flow velocities of 0.2 - 0.9 mls. An illustrative example of the use of the theory for industrial ventilation is presented.     

Evaluation of a participatory ergonomic intervention process in kitchen work

We evaluated a participatory ergonomic intervention process applied in 59 municipal kitchens. In groups of three to five kitchens, the workers participated in eight workshops, and generated and evaluated solutions to optimize musculoskeletal load in their work. An ergonomist initiated and supported the process. By the end, 402 changes were implemented. Evaluative data were collected using research diaries, questionnaires, and focus group interviews. The intervention model proved feasible and the participatory approach was mostly experienced as motivating. The workers’ knowledge and awareness of ergonomics increased, which improved their ability to tackle ergonomic problems by themselves. The changes in ergonomics were perceived to decrease physical load and improve musculoskeletal health. As hindering factors for implementation, lack of time and motivation, and insufficient financial resources were mentioned. In addition, the workers expressed a wish for more support from the management, technical staff, and ergonomists.     

Improvements and Modifications to Room‐Temperature Fabrication Method for Dielectric Li2MoO4 Ceramics

Dielectric properties of lithium molybdate disks fabricated by moistening water‐soluble Li₂MoO₄ powder, compressing it, and postprocessing the samples at 120°C, were improved by the optimization of powder particle size, sample pressing pressure, and postprocessing time. It appeared that the postprocessing temperature of the Li₂MoO₄ ceramics could be chosen so as to be applicable to the associated integrated materials as long as the postprocessing time was adequately adjusted to ensure the removal of the residual water. In addition, the dielectric properties of Li₂MoO₄ ceramic were modified with an inclusion of suitable additives. For example, at 1 GHz the relative permittivity of Li₂MoO₄ disks fabricated at room temperature and postprocessed at 120°C was increased from 6.4 to 8.8 with an addition of 10 vol% of rutile TiO₂ and to 9.7 with an addition of 10 vol% of BaTiO₃. At the same time the loss tangent value increased from 0.0006 to 0.0014 and to 0.011, respectively.     

Methods for detection of irradiation of spices

European Food Research and Technology - Three types of methods for the identification of irradiation of spices were tested as potential control methods. The methods were microbiological, combining...     

Probiotic and milk technological properties of Lactobacillus brevis

Two Lactobacillus brevis strains ATCC 8287 and ATCC 14869(T), were evaluated for their applicability as putative probiotics in dairy products. The strains expressed good in vitro adherence to human Caco-2 and Intestine 407 cells and tolerated well low pH, bile acids and pancreatic fluid under in vitro conditions. In antimicrobial activity assays, strain ATCC 8287 showed inhibitory properties toward selected potential harmful microorganisms, particularly against Bacillus cereus. Both L. brevis strains were resistant to vancomycin, which is typical for the genus Lactobacillus. The L. brevis strains were not able to acidify milk to yoghurt but were suitable as supplement strains in yoghurts. This was shown by producing a set of yoghurt products and analysing their rheological and sensory properties during a cold storage period of 28 days. Survival of the strains through human intestine was examined in 1-week feeding trials. Despite its human origin, L. brevis ATCC 14869(T) could not survive through the gastrointestinal (GI) tract, whereas L. brevis ATCC 8287 was detected in the faecal samples taken during and immediately after ingestion of the strain. In conclusion, L. brevis ATCC 8287 is a promising candidate as a probiotic supplement in dairy products.     

Vacancy formation and solid solubility in the U-Zr-N system

For the purpose of developing a nuclear fuel with enhanced thermophysical properties and better irradiation performance density functional theory calculations are used to explore UN, ZrN and (U, Zr)N. Negative deviation of ground state energy from the ideal solution model as well as energetically favourable maximal distance between substitutional metal atoms in respective nitrides indicate mutual solubility of UN and ZrN at all temperatures. Nitrogen vacancy formation energies in UN (1.81 eV) and ZrN (1.40 eV) are considerably lower than metal vacancy formation energies. A substitutional Zr atom in UN has little effect on nitrogen vacancy formation energies (∼1.79 eV), while U in ZrN decreases the value by ∼0.1 eV (∼1.30 eV) due to elastic stress and charge density redistribution in the material. The relative distance between a substitutional metal atom and a vacancy in UN has little influence over the radially declining displacement pattern induced by the substitutional atom, while in ZrN the relaxation of atoms is governed by the position of the vacancy. The calculated vacancy formation energies indicate a lower surface energy of ZrN in comparison with UN.