System Dynamics Modelling for Dynamic Emergency Response to Accidents Involving Transport of Dangerous Goods by Road

For improving the emergency capacities during road transportation accidents of dangerous goods, this paper divides the accident emergency procedure into four subsystems: accident information processing, personnel rescue and evacuation, vehicle evacuation, and rescue materials delivery. On this basis, the causal mechanism and the loop diagrams of the emergency process are established by using the System Dynamics Method and Vensim software. First, six factors including transportation distance, the degree of mechanical modernization, delay time of personnel control, delay time of traffic information release, command level coefficient, and delay time of department arrival are selected as parameters to test the model’s sensitivity analysis. Then, the influences of the abovementioned factors on the observed value, such as the demand gap of on-site materials, number of people in safe area, number of vehicles in safe area, amount of disposal information, and the dynamic evolution behavior of the system, are analyzed. The results show that the transportation distance is shortened by half, and the time to fill the demand gap is reduced by 39%. The level of mechanical modernization is doubled, the peak inventory of materials in transit will increase by 9.2%, and the time to reach the peak will be shortened by 6.8%. If the delay time of personnel control is shortened by 480 s, the number of people to be evacuated in accident area will be reduced by 56. The delay time of traffic information release is shortened by 480 s, the number of vehicles to be evacuated is reduced by 74, and the time when the vehicle stops entering accident area is 1646 s in advance. The command level coefficient increases by 9.5%, and the speed of action execution increases by 9.6%.

Effect of Postharvest Transport and Storage on Color and Firmness Quality of Tomato

Transport duration affects the vibration level generated which has adverse effects on fresh produce during transportation. Furthermore, temperature affects the quality of fresh commodities during storage. This study evaluated physical changes in tomatoes during transportation and storage. Tomatoes were transported at three distances (100, 154, and 205 km) from a local farm and delivered to the Postharvest Laboratory where vibration acceleration was recorded per distance. Tomato was stored at two different temperatures (10 °C and 22 °C) for 12 days. The physical qualities like weight loss and firmness of all tomato samples were evaluated. RGB image acquisition system was used to assess the color change of tomato. The results of vibration showed that over 40% of accelerations occurred in the range of 0.82–1.31 cm/s2 of all transport distances. Physical quality analyses like weight loss and firmness were highly affected by transportation distance, storage temperature, and storage period. The reduction in weight loss and firmness was the highest in tomatoes transported from the farthest distance and stored at 22 °C. Lightness, yellowness, and hue values showed a high reduction as transport distance increased particularly in tomatoes stored at 22 °C. Redness, total color difference, and color indices increased significantly on tomatoes transported from 205 km and stored at 10 °C and 22 °C. The study indicated that the increase in transportation distance and storage temperature cause higher changes in the physical qualities of tomatoes.

TRANSPORTATION OPTIMIZATION MODEL USING THE DISTANCE MATRIX: A CASE OF CEMENT DISTRIBUTION FROM SELECTED COMPANIES TO DISTRIBUTION CENTERS IN EBONYI STATE

Ascertaining an optimal cement distribution plan for cement companies in Nigeria has remained a challenge. The absence or fluctuation of data for estimating the cost of transporting cement from each source to each distribution center is a big stumbling block whenever modeling attempts are being made via transportation algorithms. This work has succeeded in removing these challenges by providing a Transportation Optimization Model for cement distribution using transportation Distance Matrix instead of transportation Cost Matrix. This research seeks to improve supply in the Nigerian cement industry. Three selected factories (Gboko, Port-Harcourt and Calabar) and four major distribution centers (Abakaliki, Onueke, Ohaozara and Afikpo) in Ebonyi state were considered for this work. The result of the findings using the Vogel Approximation Method, minimized the total transportation distance and by implication the total transportation costs.

AI-Driven Multiobjective Scheduling Algorithm of Flood Control Materials Based on Pareto Artificial Bee Colony

Considering the competition between rescue points, we use artificial intelligence (AI) driven Internet of Thing (IoT) and regional material storage data to propose a multiobjective scheduling algorithm of flood control materials based on Pareto artificial bee colony (MSA_PABC). To address the scheduling of flood control materials, the multiple types of flood control materials, the multiple disaster sites, and entertain both emergency and fairness of rescue need to be considered comprehensively. The MSA_PABC has the constraints such as storage quantity constraint of warehouse materials, material demand constraint, and maximum transportation distance of flood control materials. We establish the scheduling optimization model of flood control materials for each disaster rescue point and the total scheduling optimization model for all flood control materials. Then, MSA_PABC uses the modified Pareto artificial bee colony algorithm to solve the multiobjective models. Three types of initialization strategies are proposed to calculate the fitness of each rescue point and the overall evaluation value of the food source. We propose the employ bee operations such as niche technology and local search of the variable neighborhood, the onlooker bee operations such as Pareto nondominated sorting and crossover operation, the scout bee operations such as maximum evolutionary threshold, and end elimination mechanism. Finally, our proposed solution obtains the nondominated solution set and its optimal solution. The experimental results show that no matter how the number of rescue points changes, MSA_PABC can find the nondominated solution set and optimal solution quickly. It improves the convergence rate of MSA_PABC and material satisfaction rate. Our solution also reduces the average maximum transportation distance, the standard deviation of maximum transportation distance, and the standard deviation of material satisfaction rate. The evaluation also demonstrates MSA_PABC outperforms the state-of-arts such as ABC (artificial bee colony), NSGA2 (nondominated sorting genetic algorithm 2), and MOPSO (multiobjective particle swarm optimization).

Effects of Season, Plumage Colour and Transport Distance on Body Weight Loss, Dead-on-Arrival and Reject Rate in Commercial End-of-Lay Hens

Transport conditions of end-of-lay hens are important for their welfare. This study investigated the effects of season, plumage colour, and transportation distance on the welfare of end-of-lay hens. Retrospective data from 31,667,274 end-of-lay hens transported to a poultry slaughterhouse in Turkey were analysed. The mean body weight loss, dead-on-arrival (DOA) rate, and reject rate were 3.723%, 1.397%, and 0.616%, respectively. The effects of season, plumage colour, and transport distance on the evaluated parameters were all statistically significant (p < 0.001). The highest body weight loss was found in winter, while the lowest body weight loss was found in autumn. The average DOA rate was highest in spring and lowest in autumn. The highest average reject rate was found in spring (0.630%). Body weight loss, DOA rates, and reject rates were also significantly different among white and brown hens (p < 0.001; p < 0.001; p = 0.016, respectively). The highest body weight loss and reject rates were found in white plumage hens, while the highest DOA rate was found in brown plumage hens. The body weight loss and DOA rate were positively correlated with transportation distance (p < 0.001). The results of this study indicate that more preventive measures should be taken during the transport of end-of-lay hens, especially in cold seasons such as winter, and over longer transport distances, in regard to the welfare of these animals. Additionally, the transport of these animals should be lessened to a certain distance.

Improving the Return Loading Rate Problem in Northwest China Based on the Theory of Constraints

This paper introduces how to improve the return loading rate problem by integrating the Sub-Tour reversal approach with the method of the Theory of Constraints (TOC). The proposed model generates the initial solution derived by the Sub-Tour reversal approach in phase 1 and then applies TOC to obtain the optimal solution, meeting the goal of improving the return loading rate to more than 50% and then lowering the total transportation distance in phase 2. To see our model capability, this study establishes an original distribution layout to compare the performance of the Sub-Tour reversal approach with our model, based on the simulation data generated by the Monte Carlo simulation. We also conduct the pair t-test to verify our model performance. The results show that our proposed model outperforms the Sub-Tour reversal approach in a significant manner. By utilizing the available data, our model can be easily implemented in the real world and efficiently seeks the optimal solutions.

JUSTIFICATION OF TRANSPORT WORKS IN THE CONDITIONS OF A BLOCK QUARRY

The increase in oil prices, consumables and tools is necessitate the re–equipment of mining enterprises in Ukraine. The share of automobile transport reaches 35–50 % in the dimension blocks production costs. The purpose of the work is to determine transportation costs (TC) of 1 m3 of blocks depending on the volume and transportation distance within the quarry; improving the transportation plan by solving transportation problems of linear programming. Fuel consumption and dimension block TC for three models of front–end loaders (FEL) were newly calculated on the basis of a comprehensive study. A comparison of the economic feasibility of FEL and dump truck (DT) use in certain mining conditions have been made. The rationalization plan (RP) of dimension blocks transportation within the quarry was newly proposed. The research was performed at the dimension gabbro quarry, blocks transportation in which is performed using FEL CAT 988F (1) and DT KrAZ–256B. FELs CAT 988H (2) and CAT 986H (3) were adopted for comparison. The average annual fuel consumption is determined: among the FELs considered in the research, the (3) consumes the least, and the (1) currently used at the enterprise consumes 22.7 % and 9.7 % more fuel compared to the (3) and the (2), respectively, in similar conditions. Trade blocks transportation using FEL is economically more expedient in comparison with the DT at transportation distance up to 300–400 m. It is determined that the trade blocks TC using the (2) and the (3) is 5.3 % and 12.6 % lower, respectively, compared to the (1). This paper also considers the transportation problem for FELs, in which blocks from several banks must be distributed between several storage areas, provided to minimize TC. According to the proposed RP of transportation, the savings will be up to 13 % compared to the initial conditions, which in monetary terms is 41538–48639 UAH/year depending on the FEL model. The replacement of the (1) for the (3) will reduce block TC by 12.6 % (47000 UAH/year) in the current conditions. The TC using the (3) will be 285303.5 UAH according to the proposed RP, which is 23.7 % (88476 UAH/year) less than the (1) application before the rationalization. Keywords: dimension stone; front–end loader; commercial blocks transportation costs; transportation problem; cargo traffic rationalization; fuel consumption; haul road gradient.

Environmental impact assessments during construction stage at different geographic levels – a cradle-to-gate analysis of using sustainable concrete materials

PurposeThe main objective of the study is to present a systematic process that can assess, compare and benchmark different geographical levels environmental impacts of using sustainable materials at construction stage.Design/methodology/approachCurrent study presents a methodological framework to evaluate environmental impacts at the construction stage of using sustainable materials through a cradle-to-gate process based quantitative LCA study. Scenario analyses and an optimisation analysis using Monte-Carlo simulation are conducted to investigate the influence of external factors on environmental impacts at different geographical regions.FindingsMaterials account for 98% of greenhouse gas (GHG) emissions. Carbon monoxide (CO) and non-methane volatile organic compounds (NMVOC) record significant non-GHG emissions. Particulate matter (PM10) emissions are significant from transportation and equipment. High significance of global warming potential (GWP) (38.98%) and photochemical oxidation formation potential (POFP) (34.49%) at global level and eutrophication potential (EP) (52.83%) and human toxicity potential (HTP) (25.30%) impacts at local level were observed. Shortest transportation distance reduces 14.91% PM10 and 4.69% nitrous oxide (NOx) emissions. Inventory variations have major influence on POFP impact at global level. Local level impacts are not significantly affected by inventory variations. Optimisation analysis indicated, high fly ash in concrete increase local level carbon emissions, if OPC concrete transportation distance is less than 23.7 km.Research limitations/implicationsUse of case-specific information for validation may lack generalisation. However, methodology can be used for future sustainable decision making over using sustainable materials in construction.Originality/valueThe study estimate environmental impacts at different geographical levels when sustainable materials are used for construction.