scholarly journals Influence of Overheating Phenomenon on Bitumen and Asphalt Mixture Properties

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 610 ◽  
Author(s):  
Michał Sarnowski ◽  
Karol Kowalski ◽  
Jan Król ◽  
Piotr Radziszewski
Keyword(s):  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Weather Conditions ◽  
Asphalt Mixtures ◽  
Heating Process ◽  
Test Results ◽  
Adverse Weather Conditions ◽  
Loss Of Resistance ◽  
Adverse Weather ◽  
The Impact

In the course of manufacturing, transport and installation, road bitumens and asphalt mixtures can be exposed to the impact of elevated process temperatures exceeding 240 °C. This mainly applies to the mixtures used for road pavements and bridge deck insulation during adverse weather conditions. The heating process should not change the basic and rheological properties of binders and the asphalt mixtures that to a degree cause the degradation of asphalt pavement durability. The work involved analyzing the properties of non-modified bitumens and SBS polymer modified bitumens, heated at temperatures of 200 °C, 250 °C and 300 °C for 1 h. Next, the asphalt mixtures were heated in the same temperatures. Based on the developed Overheating Degradation Index (ODI) it was demonstrated that polymer-modified bitumens were characterized by higher overheating sensitivity A(ODI) than non-modified bitumens, which was confirmed by mixture test results. Overheating limit temperatures T(ODI) were determined, which in the case of polymer-modified bitumens are up to 20 °C lower than for non-modified bitumens. When the temperature increases above T(ODI), loss of viscoelastic properties occurs in the material which causes, among other effects, a loss of resistance to fatigue cracking.

Impact of Variable Speed Limit in a Connected Vehicle Environment on Truck Driver Behavior under Adverse Weather Conditions: Driving Simulator Study

2019 ◽  
Vol 2673 (7) ◽  
pp. 132-142 ◽  
Author(s):  
Guangchuan Yang ◽  
Mohamed M. Ahmed ◽  
Sherif Gaweesh
Keyword(s):  
Driving Simulator ◽  
Weather Conditions ◽  
Truck Drivers ◽  
Connected Vehicle ◽  
Variable Speed ◽  
Variable Speed Limit ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Advisory Speed ◽  
The Impact

In 2015, the U.S. Department of Transportation (U.S. DOT) selected Wyoming as one of three sites to develop, test, and deploy a suite of connected vehicle (CV) applications on a 402-mi Interstate 80 corridor. One of the Wyoming’s key CV applications is the variable speed limit (VSL) warning, which aimed to provide commercial truck drivers with real-time regulatory and advisory speed limits to help in better managing speeds under adverse weather conditions, and reducing potential speed variances that may cause traffic collisions. This paper developed a driving simulator testbed to assess the impact of the Wyoming’s CV-based VSL (CV-VSL) application on truck drivers’ behavior under adverse weather conditions. A total of 18 professional truck drivers were recruited to participate in the driving simulator experiment. Participants’ instantaneous speeds at various locations were collected to reveal the impact of the CV-VSL warnings on their driving behavior. Simulation results showed that when the advisory speed limits were lower than 55 mph, participants generally followed the VSLs displayed on the CV human–machine interface (HMI). In addition, traffic flows utilizing CV-VSL technology tend to exhibit lower average speeds and speed variances compared with baseline scenarios. These effects of CV-VSL warnings can bring potential safety benefits, as reduction in average speeds and speed variances are effective surrogate measures of safety, that is, lower risk of crashes, under adverse weather conditions.

Effect of Stern Flaps on Powering Performance of the FFG-7 Class

1993 ◽  
Vol 30 (01) ◽  
pp. 39-50
Author(s):  
William L. Cave ◽  
Dominic S. Cusanelli
Keyword(s):  
Fuel Consumption ◽  
Weather Conditions ◽  
Full Scale ◽  
Wave System ◽  
Test Results ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Before And After ◽  
The Cost ◽  
Percent Decrease

The effect of a stern flap on the powering performance and annual fuel consumption of an FFG-7 Oliver Hazard Perry Class Guided Missile Frigate is presented. Analytical analysis using free surface potential flow theory was conducted to evaluate the flow on the afterbody of the ship. Model tests were conducted to determine the optimum geometrical characteristics of the stern flap. Based on the analytical and model test results, a stern flap was retrofitted to an FFG-7 Class frigate, and full-scale results on powering performance were collected. Results of model powering experiments showed that the flap, set at 10 deg trailing edge down, decreased the delivered power by 8.4 percent at 26 knots, and provided for a 3.8 percent decrease in annual fuel consumption. This decrease in annual fuel consumption places the payback period on the cost of the flap installation at only 10 months. The full-scale comparison of the flap's effectiveness was marred by adverse weather conditions and differences in the pre-and post-flap ship configurations. However, observations of the full-scale stern wave system, before and after the installation of the stern flap, lead the authors to conclude that the flap will produce a larger decrease in delivered power at full scale than shown by the model experiments.

scholarly journals Nie tylko „generał Mróz ” wpływ czynników pogodowych na przebieg kampanii rosyjskiej Napoleona na wybranych przykładach

2020 ◽  
Author(s):  
Dawid Gralik
Keyword(s):  
Drinking Water ◽  
Weather Conditions ◽  
Cold Winter ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
The Impact ◽  
Intense Heat

Napoleon’s Russian campaigns one of the best known examples of the impact of weather conditions on the process of military actions. In the article, on selected examples, the influence of weather on the actions and condition of both armies, mainly the Great Army, is analyzed. Adverse weather conditions accompanied the 1812 warfare from the very beginning in the form of a storm that took place at the turn of June and July. Then a period of intense heat began, which caused considerable problems for the soldiers moving in fast marches, who were also deprived of access to drinking water. Finally, the extremely cold winter, even for Russia’s climate, contributed, however not always directly, to deaths of many soldiers on both sides of conflict. Although weather is difficult to see as the main cause of Napoleon’s defeat, it was an extremely important part of 1812 military actions.

scholarly journals Pogodowe uwarunkowania działań wojennych. Wpływ warunków atmosferycznych na przebieg starć i kampanii militarnych w okresie średniowiecza. Wybrane przykłady

2020 ◽  
Author(s):  
Andrzej Niewiński
Keyword(s):  
Disease Outbreaks ◽  
Temperature Fluctuations ◽  
Weather Conditions ◽  
Military Operation ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Medieval Chronicles ◽  
Military Campaigns ◽  
Bad Weather ◽  
The Impact

The article examines the impact of adverse weather conditions and astronomical occurrences on the outcome of the selected medieval military campaigns and pitch battles. Unpredictability of weather was an important factor in medieval warfare: unexpected wind, rain, snow, heat or day-to-night temperature fluctuations could influence a military operation in a significant way. As medieval chronicles recorded, troops often suffered from famine as a result of excessive rains, droughts or adverse winds which prevented supplies from being delivered by sea. Apart from causing fatigue and exhaustion bad weather contributed to disease outbreaks and equipment damage. People were weakened physically and psychologically which reduced their fighting ability.

A Weather Index for Analysing Grain Yield Instability in China, 1952–81

1984 ◽  
Vol 97 ◽  
pp. 68-83 ◽  
Author(s):  
Y. Y. Kueh
Keyword(s):  
Grain Yield ◽  
Weather Conditions ◽  
Water Control ◽  
Weather Impact ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Regression Techniques ◽  
Long Term Trends ◽  
The Impact

This article applies standard regression techniques to examine the impact of adverse weather conditions on average grain yield per sown hectare in contemporary China. By isolating the weather impact I hope (a) to quantify the possible influence of frequent policy and organizational changes which have been so characteristic of Chinese agriculture since 1949; and (b) to show to what extent grain production in China has become more “weather-proof” after three decades of massive investment in water control and other modern inputs. I shall deal mainly with the long-term trends from 1952 to 1981, with special reference to the extraordinary 1959–61 period, during which total grain output and yield declined by an average of 21 and 12 per cent respectively (or 25 and 18 per cent for the two trough years of 1960 and 1961), measured against the benchmark year of 1957.

scholarly journals Comparative Analysis of Effectiveness of Resistance and Induction Turnout Heating

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5262
Author(s):  
Elzbieta Szychta ◽  
Leszek Szychta
Keyword(s):  
Comparative Analysis ◽  
Air Temperature ◽  
Weather Conditions ◽  
Test Results ◽  
Climatic Chamber ◽  
Traffic Efficiency ◽  
Common System ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Heating Test

Turnouts are key parts of rail roads and are exposed to adverse weather conditions such as snowfall, snow drifts, low temperatures, or sleet. Effective protection assures good turnout function and contributes to rail traffic efficiency and safety. Presently, resistance heating (RH) is the most common system of turnout heating in Europe. In this study, we attempted to implement energy-saving induction heating (IH) in order to cut costs of operation and electricity. A turnout heating test stand, including a stock-rail and a switch-rail, was executed in a climatic chamber. Air temperature was constant at the time of heating. Active power received by both the systems was identical for any measurement (450 W). Test results enabled an assessment of switch-rail position and variations of climatic chamber air temperature on growth of turnout temperatures. Effects of heating type on correct lubrication of the slide plate surface were compared. Dynamics of heating variations and their impact on effectiveness of snow or ice removal were defined for both heating systems. Turnout’s readiness for switch-rail shifting and lubrication conditions of turnout’s moving parts were compared. An in-depth comparative analysis of efficiency of RH and IH turnout heating was undertaken in the conclusion.

The Impact of Adverse Weather Conditions on Autonomous Vehicles: How Rain, Snow, Fog, and Hail Affect the Performance of a Self-Driving Car

2019 ◽  
Vol 14 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Shizhe Zang ◽  
Ming Ding ◽  
David Smith ◽  
Paul Tyler ◽  
Thierry Rakotoarivelo ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
Weather Conditions ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
The Impact

Application of dextranase in UK sugar beet factories

2011 ◽  
pp. 780-783 ◽  
Author(s):  
Garry Bowler ◽  
Simon Wones
Keyword(s):  
Sugar Beet ◽  
Treatment Plant ◽  
Weather Conditions ◽  
Effluent Treatment ◽  
Operational Parameters ◽  
Adverse Weather Conditions ◽  
Effluent Treatment Plant ◽  
Adverse Weather ◽  
The Uk ◽  
The Impact

The results and conclusions from a trial of dextranase addition to draft raw juice at Wissington factory in the UK during the 2009/10 campaign are reviewed with emphasis on the impact on factory throughput and other key operational parameters. The trial demonstrated a significant benefit on second carbonation filtration which resulted in increased throughput, reduction in process chemicals usage, improved operational stability, a reduction in limesalts and the amount of water discharged to the site effluent treatment plant. In the UK the 2010/11 campaign was severely affected by adverse weather conditions and further experience was gained from additional dextranase trials conducted at all British Sugar sites.

Sign in / Sign up

Export Citation Format

Share Document