Inter-Municipal Cooperation in Waste Management: The Case of Poland

This article seeks to present the scale of inter-municipal cooperation in waste management in Poland in the light of the role of three key factors of cooperation. The first shows spatial regularities in the distribution of inter-municipal bodies involved in waste management in Poland, both in the system of voivodeships and historical-cultural regions. The second is institutional conditions confirming the scale of the Europeanisation of public policies taking place in Poland. It embraces the implementation of the EU legal framework in the Polish legal system and the cooperative behaviour of municipalities as a result of those changes. The third is a negative verification of the assumptions of the economic theory upholding the role of financial motivation in establishing cooperation (looking for savings and economies of scale to reduce unit cost); the presented results do not corroborate this type of motivation.

Analyzing the Tradeoffs Between Economies of Scale, Time-Value of Money, and Flexibility in Design Under Uncertainty: Study of Centralized Versus Decentralized Waste-to-Energy Systems

This paper presents and applies a simulation-based methodology to assess the value of flexible decentralized engineering systems design (i.e., the ability to flexibly expand the capacity in multiple sites over time and space) under uncertainty. This work differs from others by analyzing explicitly the tradeoffs between economies of scale (EoS)—which favors designing large capacity upfront to reduce unit cost and accommodate high anticipated demand—and the time value of money—which favors deferring capacity investments to the future and deploying smaller modules to reduce unit cost. The study aims to identify the best strategies to design and deploy the capacity of complex engineered systems over time and improve their economic lifecycle performance in the face of uncertainty by exploiting the idea of flexibility. This study is illustrated using a waste-to-energy (WTE) system operated in Singapore. The results show that a decentralized design with the real option to expand the capacity in different locations and times improves the expected net present value (ENPV) by more than 30% under the condition of EoS α = 0.8 and discount rate λ = 8%, as compared to a fixed centralized design. The results also indicate that a flexible decentralized design outperforms other rigid designs under certain circumstances since it not only reduces transportation costs but also takes advantage of flexibility, such as deferring investment and avoiding unnecessary capacity deployment. The modeling framework and results help designers and managers better compare centralized and decentralized design alternatives facing significant uncertainty. The proposed method helps them analyze the value of flexibility (VOF) in small-scale urban environments, while considering explicitly the tradeoffs between EoS and the time-value of money.

The Value of Flexible Capacity Expansion Strategies in Design of Complex Decentralized Engineering Systems

This paper presents and applies a simulation-based methodology to assess the value of flexible decentralized engineering systems (i.e., the ability to flexibly expand the capacity in multiple sites over time and space). This work differs from others by analyzing explicitly the tradeoffs between economies of scale (EoS) — which favors building large capacity upfront to reduce unit cost and accommodate high anticipated demand — and the time value of money — which favors deferring capacity investments to the future and deploying smaller modules to reduce unit cost. The study aims to identify the best strategies to deploy capacity of complex engineered systems over time and improve their economic lifecycle performance in the face of uncertainty. This study is illustrated using a waste-to-energy system operated in Singapore. The results show that a decentralized design with the real option to expand the capacity in different locations and times improves the expected net present value by more than 20% under the condition of economies of scale α = 0.8 and discount rate λ = 8%, as compared to a fixed centralized design. The results also indicate that a flexible decentralized design outperforms other rigid designs under certain circumstances since it not only reduces transportation costs, but also has the advantage of flexible deployment strategies, such as deferring investment and avoiding unnecessary capacity. The results help designers and managers better compare centralized and decentralized design opportunities and to recognize the value of flexible decentralized designs in small-scale urban environments. The example also provides guidance for applying flexibility to a wider range of complex engineered systems and to determine the best strategies for deploying the capacity of systems in other urban contexts.

Selection of ore transport system for a metalliferous underground mine / Dobór systemu transportu rud w kopalni podziemnej rud metalu

The conditions of increasing competition in today’s mining industry, deepening of mines and also decreasing ore reserve and quality parameters (grade, calorie, ppm, etc.) compels to reduce unit cost for maximum benefit. In this context, optimization of machinery and equipment in technical and economical sense is required in terms of economic mining. In underground mining, as ore transport operation significantly affects profitability, optimization of the system gains importance technically and economically. In this paper, the authors studied production capacities up to 1,000,000 ton/year and orebody depths up to 1,000 m according to different haulage systems; conventional shaft hoisting, declined mine truck haulage and flexowell vertical belt applications. In model study, unit transport costs of each alternative depending on the production capacity and mine depth have been calculated.

Multi-Process Tools for Fabrication, Assembly and Inspection

Multi-process tools play an important role in improving productivity and reduce unit cost of products. In this paper, a comprehensive literature survey on multi-process tools is conducted. The objectives of this survey are to (i) understand key business drivers for multi-processing, (ii) learn the existing multi-process tools available in various applications including automotive, pharmaceutical, and electronics, and (iii) identify trends in development of multi-process tooling. The contributions have been made in the following aspects: (i) the scope and definition of multi-process tools are introduced; existing multi-process tools are classified in terms of the nature of multi-processes, the targeted objects, and the applications. (ii) Pros and cons of multi-process tools are discussed and used as criteria to determine some principals in selecting right applications. (iii) Some under-developing areas related to multi-process tools have been identified and the principals of adapting multi-process tools have been determined.

RESEARCH ON BULK MICRO-MACHINED MICROELECTRODE BIOSENSOR

A new silicon-based amperometric microelectrode biosensor produced using bulk micromachining technology is presented here. Bulk micromachining, platinization and polymerization of pyrrole enhance sensitive coefficient, thus helping to miniaturize its dimensions and reduce unit cost. To our knowledge, platinization and polymerization of pyrrole is first used consecutively for microelectrode surface modification. Successful experimental results have been achieved for glucose detection. Compared to conventional amperometric biosensors and amperometric microelectrode biosensors made with surface micromachining technology, it has several advantages, such as smaller sensing surface area (1 mm × 1 mm ), lower detection limit (1×10-4 M ), larger sensitive coefficient (39.640 nA mM -1 mm -2), broader linear range (1 × 10-4-1 × 10-2 M ), better replicability (3.2% RSD for five respective detections) and stability (enzyme efficiency remains well above 95% after being stored for a month), easier to be made into arrays and to be integrated with processing circuitry, etc.