Wavelet transfer function in the analysis of the influence of a palm grip on actual vibrations of an upper limb.

Algorithms used to determine the vibrations to which hand-tool operators are exposed take into account only vibrations measured on a tool. Thus, the significant influence of constraints joining the elements of the tool-operator system is neglected. This paper attempts to determine the influence of grip on vibrations recorded both on the tool and on the limb. The estimation was based on the use of the wavelet transfer function, in which the analysis was done by filtration with wavelet functions. Signals recorded with the specially designed system were utilised in investigations.     

Perceived landscape values and public participation in a road-planning process – a case study in Sweden

The European Landscape Convention indicates that assessment of different dimensions that exist in landscapes should be taken into account in planning. In this study, we first investigated ecological, cultural and social values as perceived by the local people in a highway-planning process in Sweden. Next, we explored which factors influenced the local people's participation in the road-planning process. We used questionnaires, planning documents and the Theory of Planned Behavior to investigate the relations between different factors and local people's participation in the planning process. The results showed that people presumed the ecological values in the landscape to be adversely affected by the new road, while the social values would remain the same. Landowners had heard of the participatory-process, but few participated. Those who lived within 300 m of the road were more active in the planning process than people living further away. The findings suggest that people living within a few hundred metres of the road should be treated as key stakeholders in the planning process. The involvement of other stakeholders, and when in the public participation process stakeholders should be involved, is also discussed.     

Application of a new generation of complexing agents in removal of heavy metal ions from different wastes

Complexing agents are extensively applied in many fields of industry. They are used to provide effective controlling trace metal ions in cleaning industries, textile, pulp and paper production, water treatment, agriculture, food industries, etc. Recently, the low biodegradability of these ligands and their accumulation in the environment has become a cause for concern. Therefore, replacement of ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid by more environmentally friendly chelating agents is highly desirable. So far, these acids and their salts have been applied as components of household chemistry, cosmetics, modern microelement fertilizers and agrochemicals. This paper reviews the sorption of heavy metal ions such as Cu(II), Zn(II), Cd(II) and Pb(II) in the presence of the above-mentioned complexing agents on commercially available anion exchangers of different matrix. The obtained sorption results were fitted using the Langmuir and Freundlich sorption isotherm models. The kinetic data were also analysed using the Lagergren, Ho and McKay sorption kinetic equations. The studies were carried out considering the effects of such important parameters as phase contact time, initial concentration, pH and temperature.     

Multiple insemination increases reproductive success of female Montandon’s newt (<Emphasis Type="Italic">Triturus montandoni</Emphasis>, Caudata,Salamandridae)

The adaptive significance of multiple matings for females is a matter of much controversy. In insects, supplying the female’s sperm reserves with portions of fresh spermatozoa may be the main function of multiple matings. This simple explanation may also be applied to other animals which produce large numbers of eggs over prolonged periods of time. We tested the fertility insurance hypothesis in Montandon’s newt (Triturus montandoni, Amphibia, Salamandridae). T. montandoni females are inseminated internally by spermatophores they have picked up, and subsequently lay eggs fertilized by spermatozoa released from the spermatheca. We compared the reproductive success of singly and multiply inseminated females of Montandon’s newt in the laboratory. Multiply inseminated females laid more eggs and had a lower percentage of non-developing eggs than females who mated only once. Our data suggest that remating increases the reproductive success of multiply inseminated females by replenishing sperm reserves in the spermatheca or by supplying females with fresh portions of spermatozoa with high fertilizing capacity. Received: 7 January 2000 / Revised: 13 September 2000 / Accepted: 7 October 2000     

Cytotoxicity of resorcinol under short- and long-term exposure in vitro.

Cytotoxicity of resorcinol to 3T3 fibroblast in short- (3 hrs) and long-term (72 hrs or 6 weeks) exposure was investigated. The effects of resorcinol on cell viability (neutral red uptake, NRU assay), mitochondrial function (MTT assay) and total cell protein (Kenacid Blue assay) were estimated. As a model for long-term exposure an INTEGRA CL 6-WELL bioreactor was used. The concentrations of resorcinol producing 20, 50 and 80% inhibition of cell growth in the NRU test were lower than in the MTT test after 3 hrs of exposure. The use of an INTEGRA CL 6-WELL bioreactor allows continuous culturing and exposure to test chemical of cells for several weeks, but the strong adhesiveness of fibroblast and forming aggregates make it difficult to remove them from chambers. Resorcinol in concentration of 1 microg/cm(3) did not decrease the viability of cells to 50% of control in long-term exposure in the bioreactor.     

Nickel immobilization in ceramic matrix admixed with waste nickel hydroxide

WAXS examinations performed with nickel hydroxide samples heated to various temperatures showed that freshly settled wet nickel hydroxide sample contains some amount of crystalline beta-Ni(OH)(2) structure and its share increased when sample was dried during 3 weeks at ambient temperature. However, the share significantly decreased when the sample was dried at 110 degrees C and more so at 250 degrees C. Crystalline phase traces of Ni(OH)(2) disappeared after sample burning at 980 degrees C and instead the distinct presence of crystalline NiO was determined. The above samples were examined for solubility in stoichiometric amount of sulphuric acid diluted with water to pH 1.9 and 2.8. Solubility was determined by measuring nickel ion concentration in leachate by the AAS method. The dissolving rate was found to decrease with the rise of temperature to which the nickel hydroxide samples were heated. The solubility of Ni(OH)(2) sample burnt at 980 degrees C was undetectable during 90 h solubility-testing time likely due to its transformation into sparingly soluble crystalline NiO. The latter is considered to be the reason for effective immobilization of waste nickel hydroxide in ceramic prepared by blending with clay and sintering at 980 degrees C.     

Chlorfenvinphos Dermal Absorption in Rats: Histological and Ultrastructural Changes in the Skin and Internal Organs

We studied the effect of chlorfenvinphos dermal absorption on the morphological picture of blood, on the histological and fine structure of tail skin, and on the histological structure of internal organs (lungs, heart, liver, spleen, and kidney) of rats. This study was conducted on 25 white Wistar rats, the tail skin of which was—or was not—hydrated before exposure. Rat tails were soaked in 0.5% or 0.05% chlorfenvinphos for 1 hr day for 3 months. Evident tendencies for a decrease in the absolute level of leukocytes and for an increase in the absolute level of erythrocytes in all experimental animals were observed. Histopathological changes in the internal organs were mildly manifested in only a few rats, mainly as liver and pulmonary hyperaemia. Rat tail skin at the direct exposure site showed hyperceratosis, intensive desquamation, and compensatory hyperplasia.     

Ergonomics intervention on an alternative design of a spinal board

Nurses are often obliged to work in a 12-hr shift work system. We have decided to check whether such a working system constitutes an excessive load for nurses. On the basis of a questionnaire survey among nurses working in an 8-hr daytime shift system (169 nurses) and in a 12-hr shift (536 nurses), the amount of physical workload, work stress, and after-work activities were compared. Data analysis has shown that a 12-hr shift system is characterized by less significant physical workload but greater mental load. The nurses working in a 2-shift system were more tired after work, but they could spend more time on leisure activities and do housework. The data suggest that there are no significant contraindications for nurses to work in a 2-shift system.     

Dynamic Performance of Horizontal Flexible Anchor Lines During Fall Arrest— A Numerical Method of Simulation

Designing fall arrest systems, which contain horizontal flexible anchor lines is an important technical problem related to the safety of people who work at a height and need horizontal freedom of movement. The article presents a numerical simulation of the dynamic performance of horizontal flexible anchor lines during fall arrest. The model of a 2-component system—a horizontal flexible anchor line and a falling rigid mass, described with a second order non-linear differential equation—is the main element of this method. This method of simulation is realised by a computer program, which allows obtaining the most important data characterising a fall arrest. The article shows laboratory tests used for the verification of this method, which turned out to be a valuable source of information and which can be used for designing fall arrest systems.