Modelling spatio-temporal environmental data

A conceptual model for environmental data is presented with special emphasis on the ability to store spatio-temporal references of the data. Other aspects of the model are the ability to handle hierarchical data and semantics of the measurements. The model was tested with an implementation on an object-relational database management system. As a part of the test implementation, a forestry data set covering 75 years and 4900 hectares was loaded onto the database.     

Antenna phase pattern measurements at millimeter wave frequencies using the differential phase method with only one power meter

The differential phase measurement method has been improved to need the use of only one power meter instead of three power meters. This enables accurate antenna phase pattern measurements with a simplified set-up, accompanied by the reduction in cost. All advantages of the differential phase measurement method are still also available, e.g. there is no need to phase lock oscillators or to use rotary joints. The measurement results for an antenna at 110 GHz are presented. A good agreement with earlier data was obtained.     

Prevention of musculoskeletal disorders at work: Validation and reliability in a multicenter intervention study

During the years 1986–1989 The Finnish Work Environment Fund initiated a multicenter, intervention study (programme) to prevent musculoskeletal disorders at work. The programme consisted of four different projects comprising methodological, epidemiological, and interventive themes. The main results were as follows: (1) More than half of the occupational physiotherapists and physicians involved in the project felt that they did not have adequate training for testing the performance capacity of the musculoskeletal system. Several of the most commonly used musculoskeletal tests had either poor validity in predicting future musculoskeletal troubles or had poor reliability. (2) A controlled intervention study showed that active training of neck-shoulder muscles can prevent musculoskeletal troubles, even more than ergonomic actions. (3) It is possible to reduce sick-leave due to low-back disorders by intervention measures directed toward both the work (environment, tools) and the workers (working methods, positive attitude to work, preparedness to keep fit). (4) The identification of ergonomic hazards with the help of teamwork proved to be feasible. The practical improvements, however, were difficult to implement in the prevailing conditions. Some of the improvements increased the work load and the stress of the workers. This aspect needs further consideration.     

Bonelike Hydroxyapatite Induction by a Gel-Derived Titania on a Titanium Substrate

Gel-derived titania coating on commercial pure (c.p.) titanium induces hydroxyapatite formation onto its surface from a simulated body fluid (SBF, a metastable calcium phosphate solution). The induced apatite is similar to bone apatite in that it is poorly crystallized, calcium-deficient, and carbonate-containing. Furthermore, the carbonate (CO^2–3) groups go into the apatite lattice and lie at the positions of PO^3–4 and OH^– to replace these ionic groups, resembling the (CO^2–3) groups of bone apatite. Therefore, the apatite induced by the gel-derived titania is said to be bonelike. A chemical stimulation, stemming from abundant hydroxyl groups and negative charges at the surface of the titania gel, is believed to be responsible for the bonelike apatite induction. The potential of bone-bonding is predicted for the gel-derived titania, for it is an efficient bonelike apatite inducer in the SBF.     

Determination of positional distribution of butyryl groups in milkfat triacylglycerols,triacylglycerol mixtures,and isolated positional isomers of triacylglycerols by gas chromatography and1H nuclear magnetic resonance spectroscopy

Positional isomers (1-butyryl-2X-3Y-rac-glycerol and 2-butyryl-1X-3Y-rac-glycerol;X,Y=long-chain acyls) of saturated triacylglycerols (TAG) with 34 and 40 acyl carbons were shown to separate in two chromatographic peaks on immobilized phenyl(65%) methylsilicone column by gas-liquid chromatography, and on reversed-phase ODS-1 column by high-performance liquid chromatography. The analysis of 500-MHz¹H nuclear magnetic resonance (NMR) spectra showed distinct differences between 2-butyryl-1X-3Y-rac-glycerol and 1-butyryl-2X-3Y-rac-glycerol isomers in the resonance signals of methylene and methine protons of glycerol backbone, and carbon-2 methylene of acyl groups, and methyl protons of butyryl group. The¹H NMR spectra of three interesterified mixtures of three monoacid TAG containing saturated butyrate and caproate TAG and unsaturated butyrate TAG showed that triplets of methyl protons of butyryl groups atsn-1(3)- andsn-2-positions in saturated and unsaturated TAG had similar chemical shifts and that the chemical shift of caproyl methyl protons was different from those of butyryl methyl protons. The positional distribution of butyryl groups in isolated positional isomers of butyrate TAG, interesterified TAG mixtures, and natural and interesterified butteroil can be determined by integration of these signals.     

Predicting the health risks related to whole-body vibration and shock: a comparison of alternative assessment methods for high-acceleration events in vehicles

In this paper, alternative assessment methods for whole-body vibration and shocks are compared by means of 70 vibration samples measured from 13 work vehicles, deliberately selected to represent periods containing shocks. Five methodologies (ISO 2631-1:1997, BS 6841:1987, ISO 2631-5:2004, DIN SPEC 45697:2012 and one specified by Gunston [2011], ‘G-method’) were applied to the vibration samples. In order to compare different evaluation metrics, limiting exposures were determined by calculating times to reach the upper limit thresholds given in the methods. Over 10-fold shorter times to exposure thresholds were obtained for the tri-axial VDV (BS 6841) than for the dominant r.m.s. (ISO 2631-1) when exposures were of high magnitude or contained substantial shocks. Under these exposure conditions, the sixth power approaches (ISO 2631-5, DIN SPEC, G-method) are more stringent than a fourth power VDV method. The r.m.s. method may lead to misleading outcomes especially if a lengthy measurement includes a small number of severe impacts. In conclusion, methodologies produce different evaluations of the vibration severity depending on the exposure characteristics, and the correct method must be selected.