A single-product network design model with lead time and safety stock considerations

Most existing network design and facility location models have focused on the trade-off between the fixed costs of locating facilities and variable transportation costs between facilities and customers. However, operational performance measures such as service levels and lead times are what motivates customers to bring business to a company and should be considered in the design of a distribution network. While some previous work has considered lead times and safety stocks separately, they are closely related in practice, since safety stocks are often set relative to the distribution of demand over the lead time. In this paper we consider a two-stage supply chain with a production facility that replenishes a single product at retailers. The objective is to locate Distribution Centers (DCs) in the network such that the sum of the location and inventory (pipeline and safety stock) costs is minimized. The replenishment lead time at the DCs depends on the volume of flow through the DC. We require the DCs to carry enough safety stock to maintain the prescribed service levels at the retailers they serve. The explicit modeling of the relationship between the flows in the network, lead times and safety stocks allows us to capture the trade-off between them. We develop a Lagrangian heuristic to obtain near-optimal solutions with reasonable computational requirements for large problem instances.     

Bench‐Top Fabrication of Hierarchically Structured High‐Surface‐Area Electrodes

Fabrication of hierarchical materials, with highly optimized features from the millimeter to the nanometer scale, is crucial for applications in diverse areas including biosensing, energy storage, photovoltaics, and tissue engineering. In the past, complex material architectures have been achieved using a combination of top‐down and bottom‐up fabrication approaches. A remaining challenge, however, is the rapid, inexpensive, and simple fabrication of such materials systems using bench‐top prototyping methods. To address this challenge, the properties of hierarchically structured electrodes are developed and investigated by combining three bench‐top techniques: top‐down electrode patterning using vinyl masks created by a computer‐aided design (CAD)‐driven cutter, thin film micro/nanostructuring using a shrinkable polymer substrate, and tunable electrodeposition of conductive materials. By combining these methods, controllable electrode arrays are created with features in three distinct length scales: 40 μm to 1 mm, 50 nm to 10 μm, and 20 nm to 2 μm. The electrical and electrochemical properties of these electrodes are analyzed and it is demonstrated that they are excellent candidates for next generation low‐cost electrochemical and electronic devices.     

Exergy analysis of industrial pasta drying process

In this study we present an energy and exergy modelling of industrial final macaroni (pasta) drying process for its system analysis, performance evaluation and optimization. Using actual system data, a performance assessment of the industrial macaroni drying process through energy and exergy efficiencies and system exergy destructions is conducted. The heat losses to the surroundings and exergy destructions in the overall system are quantified and illustrated using energy and exergy flow diagrams. The total energy rate input to system is 316.25 kW. The evaporation rate is 72 kg h^?1 (0.02 kg s^?1) and energy consumption rate is found as 4.38 kW for 1 kg water evaporation from product. Humidity product rate is 792 kg h^?1 (0.22 kg s^?1) and energy consumption rate is found about 0.4 kW for 1 kg short cut pasta product. The energy efficiencies of the pasta drying process and the overall system are found to be as 7.55–77.09% and 68.63%. The exergy efficiency of pasta drying process is obtained to be as 72.98–82.15%. For the actual system that is presented the system exergy efficiency vary between 41.90 and 70.94%. Copyright © 2006 John Wiley & Sons, Ltd.     

Culturally sensitive guided imagery for allocentric Latinos: A pilot study.

The Culturally Competent Relaxation Intervention (CCRI) was developed and assessed with 25 Latino adults. In contrast to traditional psychotherapeutic and relaxation interventions, which are highly influenced by individualistic/idiocentric (the tendency to define oneself in isolation from others) assumptions, the CCRI was designed according to an allocentric self-orientation (the tendency to define oneself in relationship with others), which is prevalent among Latinos. This pilot study found preliminary evidence suggesting that participants who were more allocentric had higher levels of treatment adherence and, contrary to what was expected, idiocentric levels were not inversely related with treatment adherence. In addition, as hypothesized, it was found that higher levels of treatment adherence were related to reductions of anxiety symptoms. These findings are consistent with the predictions of the cultural match theory, which proposes that patients adhere and benefit more from interventions that fit their own cultural characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of transport properties of poly(methylmethacrylate-co-methacrylic acid) ion-containing membranes

Several membranes prepared from poly(methylmethacrylate-co-methacrylic acid) and its Li⁺ and Zn²⁺ ionomers were tested for NaCl, creatinine and urea permeability. The permeabilities of the membranes were explained on the basis of pore contents determined from their scanning electron microscope micrographs. All the membranes showed higher permeabilities during the first 2 hours of experimentation. Introduction of Zn²⁺ ions into the copolymer as crosslinking agent did not have much effect on the membrane properties but the properties of the copolymer were modified.     

Investigation of wind energy potential of Muradiye in Manisa,Turkey

The purpose of this survey is about to investigate wind energy potential of Celal Bayar University Muradiye Campus. The experimental system was commissioned in November 2006 and performance monitoring tests have been conducted since then. Author also undertake a case study to investigate how varying wind speeds considered affect the electricity production of the wind turbine system and to estimate a capacity factor which is defined as the ratio of the average power output to the rated output power of the generator. The collected data are quantified and illustrated in the tables, 07th of November 2006 till 09st of December 2007 for comparison purposes. According to experimental studies between 2006 and 2007 years, yearly average wind velocity is found to be 3.21 m/s at 30 m height and capacity factor is estimated to be 14.1% for Enercon E48 (800 kW) wind turbine. According to these results, the mean wind speed does not provide economical electricity production from the wind energy.     

Energetic performance test of an underground air tunnel system for greenhouse heating

The main objective of the present study is to investigate the performance characteristics of an underground air tunnel (UAT) for greenhouse heating with a 47 m horizontal, 56 cm nominal diameter U-bend buried galvanized ground heat exchanger. This system was installed in the Solar Energy Institute, Ege University, Izmir, Turkey. Based upon the measurements made in the heating mode, the average heat extraction rate to the soil is found to be 3.77 kW, or 80.21 W/m of tunnel length, while the required tunnel length in meters per kW of heating capacity is obtained as 12.46. The entering air temperature to the tunnel ranges from 14.3 to 21.5 °C, with an average value of 15.5 °C. When the system operates, the greenhouse air is at a minimum day temperature of 13.1 °C with a relative humidity of 32%. The maximum heating coefficient of performance of the UAT system is about 6.42, while its minimum value is about 0.98 at the end of a cloudy and cold day and fluctuates between these values at other times. The daily average maximum COP values for the system are also obtained to be 6.42. The total average COP in the heating season is found to be 5.16.     

Effect of high temperature and cooling conditions on aerated concrete properties

In this study, effect of elevated temperatures and various cooling regimes on the properties of aerated concrete is investigated. Air cooled materials are tested at room temperature and in hot condition right after the fire. Water quenching effect is determined by testing the material in wet condition right after the quenching and in dry condition at room temperature. Unstressed strength of the material tested hot is relatively higher than air cooled unstressed residual strength up to 600 °C. On the other hand, water quenching decreases the percentage of the strength particularly when the material is wet right after the quenching; strength is lost gradually as the temperature rises. As a result, if the quenching effect is disregarded, temperature rise does not have a considerable effect on the strength of the aerated concrete approximately up to 700–800 °C. It is able to maintain its volumetric stability as well. However, more care needs to be taken in terms of its use above 800 °C for fire safety.