Assessing road investments: accessibility changes,cost benefit and production effects

Infrastructure investment projects and programmes are generally evaluated by comparing project costs with pertinent benefits. In this paper a series of alternative national road investment programmes in Sweden are examined. Each programme is assessed in terms of expected time savings and reduced accident rates. In addition we make use of a general production function with regionally specific accessibility characteristics as arguments. With this approach, improved accessibility implies an increase of the production potential. The paper compares the value of these production effects with the value of time savings and other benefits in a standard CB-calculation. In the comparisons more than 50 alternative national investment programmes are assessed, and their degree of consistency is estimated.An earlier version of this paper was presented at the European RSA-conference in Moscow, August 1993 and has benefitted from comments during the conference. The authors are grateful for suggestions rendered by two anonymous referees. We also wish to thank R. Jonsson, G. Lindberg and L.-G. Mattsson. Supply of data and research funds from the National Road Administration is acknowledged.     

Quantification of aroma vapours sorbed in polyethene films using supercritical carbon dioxide

Extraction with supercritical carbon dioxide was used to quantity the amounts of seven different aroma vapours sorbed in polyethene films. The method was found to completely extract all aroma compounds from the films. The solution of aroma compounds in the polymer films decreased with increasing polymer density. Monoterpenes were always completely sorbed in the films, whereas aldehydes and ketones had a much lower affinity for the films. The sulphur-containing compound, thiophene, was difficult to analyse due to its adsorption on metal surfaces.     

The electrochemical properties of imidazol-linked iron phthalocyanine—carbon electrodes

Electrodes for the electrochemical reduction of oxygen have been studied galvanostatically. The electrodes were of the activated carbon-polymeric iron phthalocyanine (FePc) type, made hydrophobic with a Teflon treatment. A link between the FePc and the carbon was achieved by covalently binding imidazol to the carbon surface and then letting the FePc co-ordinate to the free nitrogen of the imidazol molecule. In this way an initial improvement of the stability of the electrode potential and the polarization data was achieved. It has furthermore been established that the potential responds more rapidly to changes, i.e. it is more reversible, than an analogous electrode based on carbon that has not been treated with imidazol.     

Prediction of development of fatigue during a simulated ambulance work task from physical performance tests

The aims of this study were (1) to identify which physical performance tests could best explain the development of fatigue during a simulated ambulance work task, (2) to investigate the effect of height and weight and (3) to investigate in what respects these findings differ between female and male ambulance personnel. Forty-eight male and 17 female ambulance personnel completed a test battery assessing cardio-respiratory capacity, muscular strength and endurance, and co-ordination. The subjects also completed a simulated ambulance work task -- carrying a loaded stretcher. The work task was evaluated by development of fatigue. Univariate and multiple regression analyses were used to investigate to what extent the tests in the test battery were able to explain the variance of developed fatigue. The explained variance was higher for female than for male ambulance personnel (time > 70% of HRpeak: R2 = 0.75 vs 0.10, accumulated lactate: R2 = 0.62 vs 0.42, perceived exertion: R2 = 0.75 vs 0.10). Significant predictors in the models were VO2max, isometric back endurance, one-leg rising, isokinetic knee flexion and shoulder extension strength. Height, but not weight, could further explain the variance. The high physical strain during carrying the loaded stretcher implies the importance of investigating whether improved performance, matching the occupational demands, could decrease the development of fatigue during strenuous tasks.     

Interface quality and thermal stability of laser-deposited metal/MgO multilayers

Metal/MgO multilayers (metal of Fe, Ni80Nb20, and Ti) with bilayer periods in the range 1.2-3.0 nm have been prepared by pulsed laser deposition and characterized by both hard and soft-x-ray reflectometry. The interface roughness is found to be < or = 0.5 nm in all the samples and is nearly independent of the total number of deposited bilayers. The interface roughness, however, depends on the absolute thickness of the individual layers and increases from approximately 0.3 nm for a 3.0-nm period to approximately 0.5 nm for a bilayer period of 1.2 nm. The multilayers are found to be highly stable up to temperatures as high as 550 degrees C. The hard-x-ray reflectivity of the multilayers decreases for T > 300 degrees C, whereas the layered structure is stable up to 550 degrees C. The reflectivity in the water window region of soft x rays, lambda = 3.374 nm, was found to be 0.4% at an angle of incidence of approximately 54 degrees for multilayers with 60 bilayers at a period of approximately 2.1 nm.     

Consumer and sensory investigations in relation to physical/chemical aspects of cooked pork in Scandinavia

The present study addresses sensory quality and liking for pork (eight samples) varying in quality due to adrenaline injection resulting in elevated ultimate pH post-slaughter (24h), meat ageing, cooking temperature and warmed-over flavour (WOF) among consumers (n=288) in Scandinavia. The consumers preferred meat with higher pH (pH(24h)=6.0), cooked to the lowest temperature (65?°C versus 80?°C). Consumers least preferred samples with WOF described as metallic, acidic and off-flavour by a trained panel. "Elevated pH(24h) meat" cooked to 65?°C resulted in a more sweet and tender meat. Juiciness, tenderness and the absence of off-flavour were the most important characteristics for consumers' liking of pork. Consumption frequency and liking of pork were positively related. The consumers that were most satisfied with pork quality reported highest consumption frequency. Elderly people and males expressed the highest liking score and consumption frequency, respectively.     

Titanium implants and BMP-7 in bone: an experimental model in the rabbit

This study evaluates the effect of rhBMP-7/OP-1 on the osseointegration of commercially pure titanium implants in an experimental implant model in rabbits. Threaded titanium implants with two transverse parallel canals were inserted in the femur and tibia of rabbits. The canals were filled with, 10 g of BMP-7/collagen carrier, pure collagen carrier or were left empty as a control. The stiffness of the implant fixation was evaluated by Resonance Frequency Analysis (RFA) at baseline and four weeks postoperativly. Percentage of bone ingrowth in the canals was measured on microradiographs. Histomorphometry along the threaded part of the implants was performed on 15 m thin sections. The results from the RFA demonstrated a higher mean value for the BMP-7 treated implants in the tibia than the carrier treated implants but not compared to the control implants. The control implants in the tibia demonstrated more bone ingrowth in the upper canal than to the carrier or the BMP-7 treated implants. Apart from these differences there were no significant effects of BMP. In this study BMP-7 did not contribute to any substantially improved bone anchorage of titanium implants.