Showing papers by "Ontario Ministry of Transportation published in 1985"

Temporal relations between blood alcohol concentration and alcohol effect: an experiment with human subjects

Abstract: Each of 40 fasting human subjects (20 men and 20 women) consumed 1 g ethanol (absolute) per kilogram body weight as a 20% solution by volume in organge juice. The time to peak BAC was found to be 24.0 min later than the time to peak alcohol effect as measured by magnitude estimation. This difference is both large and statistically reliable. These data are compared with those in the literature which usually show these events to be synchronous. Discussion includes reasons for this empirical discrepancy, implications of the theory of acute tolerance, and plans for future research. Examination of group data shows the same general trends obtained in the analysis of individual data: alcohol-effect scores reach peak earlier than BAC for the group as a whole (n=40), or for men alone, or for women alone. Moreover, alcohol-effect scores decline more rapidly in later trials than BAC scores, as has been reported earlier.

Simultaneous Multielement Determination of Trace Metals in Seawater by Inductively Coupled Plasma Atomic Emission Spectrometry Using Chelating Resin Column Preconcentration

Abstract: Preconcentration of trace metals in seawater using a Chelex-100 resin column was investigated for simultaneous determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimum preconcentration conditions were examined in detail. With 100 ml of 1 M ammonium acetate buffer solution (1 M=1 mol dm−3), the matrix elements in seawater could be removed sufficiently without loss of analytes. The concentration factor of 200 times could be achieved by dissolving the dried HNO3 eluent of the column. The blanks of the method were negligibly small for most elements investigated. The detection limits were in the range of several ng/1 to 100 ng/1 for Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, and Zn. The present technique was applied to the determination of trace metals in coastal and ocean seawater.

Experimental Study on Wind Driven Current in a Wind-Wave Tank

Abstract: The wind driven current were investigated in a wind-wave tank in which a false bottom was installed in order to control the return flow. The ratio of the surface velocity to the mean wind velocity in the case without return flow increased up to 3.8% and this is greater than that in the case with return flow in which the ratio was 3.3%. The velocity distribution of wind driven current applicable for both cases with and without return flow was derived.

Salt-marsh research with respect to the civil-engineering project in The Oosterschelde, The Netherlands

Abstract: This paper describes environmental research necessary for a large coastal engineering project like the Delta project in the south-west Netherlands. Special attention is paid to environmental aspects concerning salt marshes in the Oosterschelde.

A computer model for forecasting ocean wave parameters at specific sites around the the New Zealand coast

Abstract: An applications model for forecasting frequency‐directional wave spectra at any appropriately specified site is described. There are two stages to the calculations. Firstly, a spectrum is calculated based on results at nearby gridpoints from an ocean wave prediction model. This is then adjusted to make the spectrum consistent with the local wind history. Verifications of the model are made at sites off Cape Egmont and Great Barrier Island, North Island, New Zealand. These give encouraging results for the shape of the frequency spectrum, with reasonable skill evident in the energetic parts of the spectrum. The significant wave heights also agree well, with the model estimates explaining two thirds of the measured variance.

Correcting Flexible Pavement Deficiencies: The Ontario Way

Abstract: Ontario emphasizes preservation of their highway system by carrying out maintenance activities aimed at prolonging the life of highway pavements. To make the maintenance task easier and more effective, a set of guidelines was developed that helps maintenance staff make the best decision, one that is most cost-effective and one that is made consistently by different maintenance staff. For the most part, the guidelines deal with short-term measures - deficiencies that have to be fixed right away, that is, corrective maintenance. But they can also be used to identify situations where preventive maintenance will affect the service life of the pavement. The guidelines contain the following elements: 1) identification process, 2) treatment selection, and 3) performance standard. The paper describes the current practice of identifying and classifying a typical deficiency, selection of the most cost-effective treatment, the specifications for equipment and materials needed to carry out the treatment, and the proper work methods. As a typical example, this paper will describe flexible pavement crackings and cracks that are routed and sealed as the prescribed treatment. For the covering abstract of the symposium see IRRD 286635. (Author/TRRL)

Spatial variability and variations in bedload transport direction in a subtidal channel as indicated by sonographs

Abstract: Three sonographs of a part of a subtidal channel, located in the Oosterschelde, are described and interpreted. The sonographs are used to determine the asymmetry of the bedforms. Current profiles and directions are used to explain differences in dimensions and characteristics of the bedforms. The relations between current velocity parameters and bedform characteristics in intertidal zones do not apply to subtidal forms. The division in the depth-velocity diagrams between the types of 2d and 3d bedforms of Dalrymple et al. (1978) is not valid.

An experimental study on sliding rigid body in water during earthquakes

Abstract: Shaking table tests of model blocks were conducted to study sliding behavior of a rigid body in the water during earthquakes. The accelerations and hydrodynamic pressures on the model block decreased instantaneously on set of sliding and remained the same levels during sliding. The static and dynamic coefficients of friction obtained from the vibration tests in consideration of the added mass of which inertia force corresponded to the hydrodynamic pressures on the model block were almost the same values as those measured by Euler's method. A method to estimate the displacements of the sliding block during earthquakes was presented. The displacement calculated from the horizontal and vertical base accelerations showed relatively good agreement to the measured value.

Glacial Striae and Crescentic Marks in Nepean Sandstone near Ottawa

Abstract: An outcrop of Nepean Sandstone (Cambro-Ordovician) at Kanata, 21 km west of Ottawa, containing a unique concentration, diversity and distribution of glacial striae and crescentic markings has been partly removed by highway construction, leaving the north sloping stoss end and part of the top surface. Two sets of striae are preserved. The main set, indicating ice flow toward the south-southwest across the Ottawa Valley, is transected by short, deep, west-east striations indicating a late and final ice flow downvalley to the east. East-trending striations are seldom observed in the Ottawa Valley. Crescentic markings variously termed gouges, scours, scars, or pluckings, are on the northern stoss slope, concave up-ice toward the north. On average, these are 25cm across, about 5 cm broad and 1 to 2.5 cm deep. They become progressively less crescentic and less concave away from the stoss slope and change to fine, hairline fractures on the more polished top surface, becoming convex up-ice toward the southern end of the outcrop. The change in crescentic form from north to south along the outcrop clearly represents a differential impingement of ice and its contained boulders over the surface of the outcrop.

Corrosion Surveys of Steel Structures under Marine Environment

Abstract: For studying the corrosion of steel structures under marine environment and for examining the effectiveness of corrosion protection, 229 port facilities with steel members were surveyed. In some of them, concentrated corrosions were found just below the mean low water level and the rate of corrosion where the severest concentrated corrosion had taken place was estimated to be larger than 0.93 mm/yr. Except such places, the corrosion rates of steel in sea water and bottom soil were about 0.1 mm/yr. In the structures to which the corrosion protection with the electrode of aluminum alloy was applied, the protection potentials were maintained below the corrosion potential and no concentrated corrosion was found.

Prevention of Escaping Oil from Mechanical Barriers in the Presence of Water Currents

Abstract: In the case of accidents of oil tankers and seaside oil refineries, oil control barriers are usually set on the sea surface to prevent spilled oil from spreading, many types of these barriers have been developed so far However, the conventional oil control devices are not always effective for containing oil slicks on the actual sea surface Hence, the improvement in the performance of barriers has been required especially for the high values of current velocity, wave height and wind velocity

Water Leak Tests of Ferrocement in Tension

Abstract: Water tightness comes up as an important problem for water retaining structures. Watertight crack width is considered to be one of the limit states on design and inspection for use. In this paper, water leak tests in tension were carried out on ferrocement plates. The leak stress, the crack width at each water leaking stage and failure, and the crack spacing were observed experimentally.

Research on Resistance of Concrete to Seawater

Abstract: The characteristics of concrete specimens immersed in seawater for 10 years were investigated. In general, concrete immersed in seawater expanded more than in case of standard curing (20°C in fresh water), and it was estimated that expansion would progress even after 10 years. The compressive strength of Portland cement concrete immersed in seawater was lower at 10 years than 3 years, but did not decline very much with blended cement concrete. However, all seawater-immersed specimens were of lower compressive strengths than specimens with standard curing. Surface deterioration of specimens in surface appearance and compressive strength were unrelated. According to the results of chemical analyses of the concretes, the surface portions and the interiors were of different compositions with MgO, SO3, and Na2O plentiful at the surface portions with CaO conversely small in quantity. As for Cl, it had penetrated to the centers of the specimens.

Long-Term Prediction Model of Phosphorus in Bed Material

Abstract: A numerical model is developed on the bottom phosphorus behaviors which are closely related with internal production of marine organics. The variation of O-P settling rate and dissolved oxygen are assumed by the record from 1880 to 1983. T-P and I-P in the sediment, PO4-P in interstitial water, and PO4-P release rate from sediment surface are simulated to the natural values in a specific point. According to the simulation result, PO4-P release rate slightly exceeds observed values in summer times, but the seasonal variation and the annual release rate of PO4-P display agreeable values with the observed. Furthermore, T-P and O-P concentrations of the sediment, and interstitial PO4-P approach to an asymptotic value to observed values. This model is expected to offer powerful means for the long-term prediction of phosphorus or the estimation of sediment treatment works.