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Open access

Muse Olayiwola Solanke, Bashiru Adisa Raji and Taiwo Kareem Alli

Abstract

Vehicle is an important element of transport; and its financing especially in road transport comes in 3 ways; outright purchase, hire purchase and lease. Of all these three methods of road transport financing, leasing has attracted little attention in Nigeria transport research. This study was carried out to examine the development, types and form, operating characteristics and problems of vehicle lease in Lagos State, Nigeria. Aggregate number of vehicle leasing companies in Nigeria from inception to 2018 was obtained from corporate affairs commission (CAC). Four prominent vehicle leasing companies: Cashlink Leasing Plc (CLP), NIKKY Taurus Ltd (NTL), C & I Leasing (CIL) and SAMTL Leasing Ltd (SLL) were purposively selected for the operating characteristics and challenges of the leasing companies. 298 structured questionnaires were administered to the staffs of the selected companies seeking the types and forms of lease and challenges encountered in the course of operation using stratified and simple random samplings techniques. Vehicle leasing started in Nigeria from 1986 with the likes of pine hill leasing, Cashlink leasing, VT leasing in Lagos. Within 1986 and 2018, it has spread to 23 different urban cities and the number has increased to 297 companies in 2018. Operating and finance leases exist in the industry with majority of 91.6% of the companies practice operating lease. The staff strength and fleet size level of the leasing companies varies overtime but positively significant to their operations. However, poor pricing of lease service, inadequate finance of vehicle, default in payment of rental charges and high cost of maintenance minimize leasing service efficiency and effectiveness. It is recommended that government should provide subvention for vehicles acquisition, face-off of racketing vehicles from cites and legislate policy to regulate operational activities (entry and exit) of the companies.

Open access

R. Saraswathy, Jijo James, P. Kasinatha Pandian, G. Sriram, J. K. Sundar, G. Swarna Kumar and A. Sathish Kumar

Abstract

The present study involved the utilization of crushed glass as an auxiliary additive in the manufacture of cement stabilized fly ash (CSF) bricks. The bricks were made with 1:1 proportion of fly ash and sand stabilized with 20 % cement. Crushed glass was used as replacement for the fine aggregate in increments of 10 % up to 40 % wherein the sand was completely replaced with crushed glass. The various mix proportions were then moulded into bricks with the addition of water by hand moulding method of forming the bricks and sun dried followed by sprinkle curing over a period of 21 days. The bricks were then subjected to compressive strength, water absorption and efflorescence tests to gauge its performance. The investigation revealed that the addition of crushed glass to the brick mix resulted in an increase in strength of the bricks, however, the maximum strength achieved could not achieve the strength of the control specimen. But the strength was higher than the minimum strength recommended by Bureau of Indian Standards (BIS) for stabilized blocks as well as burnt bricks. It also reduced the water absorption marginally while no efflorescence was seen in any of the combinations. A cost comparison revealed that the optimal combination with crushed glass was able reduce the cost of the brick by 20 %.

Open access

Chunhua Chen, Jianwei Ren and Yunga A

Abstract

Development of sharing economy has brought new opportunities to the development of green logistics. Pallet pooling is a typical type of sharing economy. It has been recently promoted in almost every country in the world. Researchers have reached a common agreement that establishing an effective pallet pool is of great importance to the pallets use efficiency. It is also believed that the implementation of pallet pool will substantially contribute to the economic and social development. Detailed analysis of pallet pooling such as benefit analysis, mode choose, pallet allocation model & algorithm, quality control, etc. are discussed in this paper. Based on literature review, several important problems are listed for future study. These problems are information management, supply chain management, rental pricing, pallets tracking and allocation, quality control, sustainable development (carbon emissions), and “internet plus pallet pooling”. Some suggestions on China’s pallet pooling development are proposed as well.

Open access

Jozef Komačka and IIja Březina

Abstract

The propagation of waves generated by load impulse of two FWD types was assessed using test outputs in the form of time history data. The calculated travel time of wave between the receiver in the centre of load and others receivers showed the contradiction with the theory as for the receivers up to 600 (900) mm from the centre of load. Therefore, data collected by the sensors positioned at the distance of 1200 and 1500 mm were used.

The influence of load magnitude on the waves propagation was investigated via the different load force with approximately the same load time and vice versa. Expectations relating to the travel time of waves, depending on the differences of load impulse, were not met. The shorter travel time of waves was detected in the case of the lower frequencies. The use of load impulse magnitude as a possible explanation was not successful because opposite tendencies in travel time were noticed.

Open access

Mohammad Hosein Razavi and Parviz Alipour

Abstract

Every year, many people in the world lose their homes due to natural disasters such as earthquakes, floods and so on. In critical situations, the use of prefabricated parts in the buildings has many technical and economic advantages. Hence, today, this technology is widely used in the industrialized societies. The purpose of this research is to provide an appropriate model for speeding up the process of constructing buildings using prefabricated parts in critical conditions. To do this, Analytic Network Process (ANP) approach has been used to select the best option for speeding up construction projects using prefabricated parts and in critical situations. In this study, the intended criteria are quality, time, cost, and strength. The options that we should compare and the best option among them, according to the criteria mentioned, are Lightweight Steel Frame (LSF) parts, steel parts and concrete parts. In order to find this prioritization, the viewpoints of civil engineers and construction experts have been used. It should also be noted that for the ANP method, the Super Decisions software has been used.

Open access

Sarah Bakhtiari and Mohammad Ali Nekooie

Abstract

Due to the fact that dams are considered one of the strategic infrastructures of a country, it is very important to protect it against destructive acts. Accordingly, sensors were used at various points to record structural responses to the dam. Based on the questionnaires completed by experts, accuracy had the score of 3.8 so it was considered as the most important feature of the sensors and the optical fiber sensor with a mean score of 3.93 was selected as the best sensor type among the available ones. For this project, a questionnaire was prepared based on Likert scale and SPSS method was used in TOPSIS software. Then, Seimare concrete double curvature arch dam was simulated in ABAQUS 2017 software and the proper positioning of the sensors for optimum performance was determined based on Finite Element Method analysis and according to structural control criteria such as tension, displacement, strain, velocity and so one.

Open access

Bohumil Frantál and Eva Nováková

Abstract

Wind energy research is dominated by studies of local acceptance (or not) of wind farms and comparative studies at a national level. Research on the spatial differentiation of wind energy developments at the regional level is still insufficient, however. This study provides new empirical evidence for the extent to which regional differences in the deployment of wind energy are related to specific environmental and socioeconomic factors, by a statistical analysis of data for districts in the Czech Republic. Unlike previous studies, we found that the installed capacity of wind energy cannot be well predicted by wind potential, land area and population density in an area. In the Czech Republic, wind farms more likely have been implemented in more urbanised, environmentally deprived coal-mining areas that are affected by economic depression. It seems that in environmentally deprived areas, wind energy is more positively accepted as an alternative source to coal, and the economic motivation (financial benefits for municipalities) can have a greater effect on local acceptance, while public opposition is less efficient due to lower social capital and involvement in political matters. Based on these results, some implications for the planning and spatial targeting of new wind farms are discussed.

Open access

Maciej Major, Izabela Major, Daniela Kuchárová and Krzysztof Kuliński

Abstract

In this work considerations concerning eccentrically loaded socket footing with cut-off pyramid shaped socket were presented. As an object of study sloped footing with 1.40 m height, corresponding to the maximum frost depth has been adopted. Knowing that in practice there are no perfect pure axial loads, load applied on the eccentricity has been taken into considerations. Eccentric loads result in footing rotation in the direction of eccentricity and acting load, hence one footing end is imbedding into the ground, whereas second end tries to rise up. To observe that phenomenon, elastic type of support under the foundation was introduced corresponding to the naturally humid sand with medium compaction. Presented in this paper considerations of innovative connection technology between footing and column were based on performed numerical studies. Advantages and disadvantages of presented footing in comparison to normal socket footings solutions were widely discussed. Numerical analyses were performed with the utilization Finite Element Method based SolidWorks software.

Open access

Özgür Kabadurmuş, Mehmet Serdar Erdoğan, Yiğitcan Özkan and Mertcan Köseoğlu

Abstract

Distribution is one of the major sources of carbon emissions and this issue has been addressed by Green Vehicle Routing Problem (GVRP). This problem aims to fulfill the demand of a set of customers using a homogeneous fleet of Alternative Fuel Vehicles (AFV) originating from a single depot. The problem also includes a set of Alternative Fuel Stations (AFS) that can serve the AFVs. Since AFVs started to operate very recently, Alternative Fuel Stations servicing them are very few. Therefore, the driving span of the AFVs is very limited. This makes the routing decisions of AFVs more difficult. In this study, we formulated a multi-objective optimization model of Green Vehicle Routing Problem with two conflicting objective functions. While the first objective of our GVRP formulation aims to minimize total CO 2 emission, which is proportional to the distance, the second aims to minimize the maximum traveling time of all routes. To solve this multi-objective problem, we used ɛ-constraint method, a multi-objective optimization technique, and found the Pareto optimal solutions. The problem is formulated as a Mixed-Integer Linear Programming (MILP) model in IBM OPL CPLEX. To test our proposed method, we generated two hypothetical but realistic distribution cases in Izmir, Turkey. The first case study focuses on an inner-city distribution in Izmir, and the second case study involves a regional distribution in the Aegean Region of Turkey. We presented the Pareto optimal solutions and showed that there is a tradeoff between the maximum distribution time and carbon emissions. The results showed that routes become shorter, the number of generated routes (and therefore, vehicles) increases and vehicles visit a lower number of fuel stations as the maximum traveling time decreases. We also showed that as maximum traveling time decreases, the solution time significantly decreases.

Open access

Dominik Niemiec, Roman Bulko and Juraj Mužík

Abstract

The article focuses on the use of the meshfree numerical method in the field of slope stability computations. There are many meshfree implementations of numerical methods. The article shows the results obtained using the meshfree localized Petrov-Galerkin method (MLPG) – localized weak-form of the equilibrium equations with an often used elastoplastic material model based on Mohr-Coulomb (MC) yield criterion. The most important aspect of MLPG is that the discretization process uses a set of nodes instead of elements. Node position within the computational domain is not restricted by any prescribed relationship. The shape functions are constructed using just the set of nodes present in the simple shaped domain of influence. The benchmark slope stability numerical model was performed using the developed meshfree computer code and compared with conventional finite element (FEM) and limit equilibrium (LEM) codes. The results showed the ability of the implemented theoretical preliminaries to solve the geotechnical stability problems.