Globalization, the growth of the world population, urbanization and the growth of the volume of the flow of goods have generated numerous problems in city logistics (CL). The opportunity to solve them is found in various fields by defining and implementing initiatives, concepts, measures, modern technologies and scenarios. The efficiency of the solution largely depends on the efficiency of logistics centers, which is one of the key subsystems of CL. The requirements for the reliable delivery of goods to customers in urban areas are conditioned by the efficiency their order fulfillment in logistics centers. Therefore, optimizing material handling (MH) time and costs aimed at reducing delivery errors, minimizing damage to goods and increasing customer service efficiency is directly conditioned by the automation of MH in logistics centers. Accordingly, this paper aims to rank and select smart MH solutions in logistics centers where deliveries are prepared for the supply of the city area. This paper proposes four smart solutions for a real company, and fourteen criteria are selected for the evaluation. A new hybrid Multi-Criteria Decision-Making model that combines the Fuzzy Analytic Hierarchy Process method, used to determine the criteria weights, and the Fuzzy COmprehensive distance-Based RAnking (FCOBRA) method, used to rank the alternatives, is proposed. The application of the model shows that the best alternative is the implementation of an autonomous forklift, which can greatly automate logistics activities and reduce the rate of delivery errors. The main contributions of this research are the definition of smart solutions, a framework for their evaluation and a new model for their ranking.

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Compressed natural gas is in automotive industry recognized as one of the "cleanest" fossil fuels which can be used in internal combustion engines with a number of benefits. Since natural gas has much higher octane rating than gasoline it is expected that higher compression ratios can be used. The goal of the research is to determine the change of performance of spark ignited engine with the increase of compression ratio to values similar to compression ignited engine while keeping the exhaust emissions on the acceptable level and avoiding knock combustion. Measurements are performed at compression ratios 12, 16, and 18 at three different values of air excess ratio. Methane with known composition from a pressure cylinder is used instead of natural gas and the results are comprised of indicating results (in-cylinder and intake pressure in a crank angle space), emissions, temperatures, and mass-flows on various intake and exhaust positions. Analysis of results shows high influence of compression ratio and excess air ratio on combustion, performance, and exhaust gas emissions.

Homogeneous charge compression ignition (HCCI) engine is a potential solution for reducing air pollution and for satisfying legal limits regarding the emissions from internal combustion engines. The HCCI engines have advantages of lower emissions of NO x and particulate matter, compared to the standard combustion modes, while on the other hand one of the major disadvantages is the difficulty of control of start of combustion, since the start of combustion is highly sensitive to the intake air temperature. Additional advantage of the HCCI engine is the ability to operate with wide range of fuels. In order to demonstrate this potential in this study the HCCI mode of operation is compared to the spark ignition mode of operation. The study aims to compare and characterise two different combustion modes on the same engine with different CR and different fuels at similar operating conditions. For that purpose the engine tests are performed at the same indicated mean effective pressures for the spark ignition and HCCI combustion mode at the same engine speed, while the tests are performed at three different engine speeds and three different loads. The measurements were performed on the experimental setup that consists of single cylinder Diesel engine modified to enable operation in spark ignition and HCCI modes. The characterisation includes the comparison of in-cylinder pressure, temperature and rate of heat release obtained by spark ignition and homogeneous charge compression ignition combustion mode and presents comparisons of engine efficiencies and of emissions of HC, CO, and NO x .