27 research outputs found

    Developing Model for Supply Chain Management - the Case of Croatia

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    This paper describes a model of supply chain management (SCM). It explains overall supply chain issues, strategic importance of SCM, supply chain strategies and an example of mathematical formulation. A supply chain is a global network of organizations that cooperate to improve the flows of material and information between suppliers and customers at the lowest cost and the highest speed. The objective of a supply chain is customer satisfaction. At the strategic level, a supply chain can be considered as being composed of five activities: buy, make, move, store and sell. Each activity is a module. The set of modules, along with its links, constitutes a model of the supply chain. Our paper presents some insights into the supply chain strategies of companies in Croatia. The major goal of this paper is to show a model for supply chain management in mathematical terms, with an example of mathematical formulation

    Microwave assisted biodiesel production using heterogeneous catalysts

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    As a promising renewable fuel, biodiesel has gained worldwide attention to replace fossil-derived mineral diesel due to the threats concerning the depletion of fossil reserves and ecological constraints. Biodiesel production via transesterification involves using homogeneous, heterogeneous and enzymatic catalysts to speed up the reaction. The usage of heterogeneous catalysts over homogeneous catalysts are considered more advantageous and cost-effective. Therefore, several heterogeneous catalysts have been developed from variable sources to make the overall production process economical. After achieving optimum performance of these catalysts and chemical processes, the research has been directed in other perspectives, such as the application of non-conventional methods such as microwave, ultrasonic, plasma heating etc, aiming to enhance the efficiency of the overall process. This mini review is targeted to focus on the research carried out up to this date on microwave-supported heterogeneously catalysed biodiesel production. It discusses the phenomenon of microwave heating, synthesis techniques for heterogeneous catalysts, microwave mediated transesterification reaction using solid catalysts, special thermal effects of microwaves and parametric optimisation under microwave heating. The review shows that using microwave technology on the heterogeneously catalysed transesterification process greatly decreases reaction times (5–60 min) while maintaining or improving catalytic activity (>90%) when compared to traditional heating

    Absorption spectrum in the wings of the potassium second resonance doublet broadened by helium

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    We have measured the reduced absorption coefficients occurring in the wings of the potassium 4S-5P doublet lines at 404.414 nm and at 404.720 nm broadened by helium gas at pressures of several hundred Torr. At the experimental temperature of 900 K, we have detected a shoulder-like broadening feature on the blue wing of the doublet which is relatively flat between 401.8 nm and 402.8 nm and which drops off rapidly for shorter wavelengths, corresponding to absorption from the X doublet Sigma+ state to the C doublet Sigma+ state of the K-He quasimolecule. The accurate measurements of the line profiles in the present work will sharply constrain future calculations of potential energy surfaces and transition dipole moments correlating to the asymptotes He-K(5p), He-K(5s), and He-K(3d).Comment: 2 figure

    Developments in Nanoparticles Enhanced Biofuels and Solar Energy in Malaysian Perspective: A Review of State of the Art

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    The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country's rapid expansion and financial affluence, Malaysia's energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation's accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy sources added with nanosized metal particles called as nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation's energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia's existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology

    Developments in nanoparticles enhanced biofuels and solar energy in Malaysian perspective: a review of state of the art

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    The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country’s rapid expansion and financial affluence, Malaysia’s energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation’s accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy sources added with nanosized metal particles called nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation’s energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia’s existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology

    Sustainability through production networks

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    Global economic crisis has brought into question sustainability of many industrial enterprises, especially Large-sized Enterprises (LEs). However, the strength of the European economy are not Large-sized Enterprises, but Small and Medium-sized industrial Enterprises (SMEs). As an alternative to LEs there is networking of SMEs into flexible production networks. Inside production network SMEs can collaborate on new product development forming Virtual Enterprise. SMEs collaborating as one Virtual Enterprise can be seen as a sustainable Large-sized Enterprise. However, to achieve sustainability through production networks, i.e. Virtual Enterprises, it is essential to choose an optimal combination of SMEs in Virtual Enterprise formation process. Since it is a complex task that requires the use of multi-criteria decision-making methods, in this paper PROMETHEE method is used

    Developing Model for Supply Chain Management - the Case of Croatia

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    This paper describes a model of supply chain management (SCM). It explains overall supply chain issues, strategic importance of SCM, supply chain strategies and an example of mathematical formulation. A supply chain is a global network of organizations that cooperate to improve the flows of material and information between suppliers and customers at the lowest cost and the highest speed. The objective of a supply chain is customer satisfaction. At the strategic level, a supply chain can be considered as being composed of five activities: buy, make, move, store and sell. Each activity is a module. The set of modules, along with its links, constitutes a model of the supply chain. Our paper presents some insights into the supply chain strategies of companies in Croatia. The major goal of this paper is to show a model for supply chain management in mathematical terms, with an example of mathematical formulation

    Circular economy, energy transition, and role of hydrogen

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    Circularity is not a new concept. Activities such as reuse or recycling have been around for centuries. Today, an urgent solution to tackle the increasing harmful emissions resulting in severe climate changes is being proposed and investigated. This is because a link between industry and the environment is critically important for business. A more sustainable socio-technical system is therefore urgently needed. There has been a rapid growth of academic articles on the circular economy. The circular economy concept has been considered a solution to many of today’s challenges, including resource scarcity and waste generation. </jats:p
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