Planning of waste electrical and electronic equipment (WEEE) recycling facilities: MILP modelling and case study investigation

Waste electrical and electronic equipment (WEEE) consist of many different substances some of which contain hazardous components and valuable materials. The recovery of WEEE plays a key role on environmental sustainability because it minimizes the negative effects of hazardous materials and helps the efficient use of world's limited resources. Recovery strategies enable companies to collect reusable components and to recycle the material content of WEEE by using operations like sorting, disassembly and bulk recycling. Usually companies associated with municipals collect WEEE from end-users and/or collection points. Then they sell these items to WEEE recycling facilities through bidding. For recycling facilities, it is important to generate the best operational level decisions to receive and handle WEEE. This study contributes to the fulfillment of this need by presenting a mixed integer linear programming model to determine the maximum bid price offer while determining the best operation planning strategies. In order to demonstrate the potential of the proposed model, a real life case study along with several scenarios is studied. The findings of the case study indicate that the model has the potential to enable the decision maker to come with stronger decisions related to both bidding process and operational strategies of the facility.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M428]The authors are indebted to the anonymous referees and the Editor for several suggestions, which substantially improved the paper. This research is partially funded by the Scientific and Technological Research Council of Turkey (TUBITAK) under the Grant Number 111M428. The authors wish to acknowledge this valuable support

Current worldwide nuclear cardiology practices and radiation exposure: results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS)

AIMS: To characterize patient radiation doses from nuclear myocardial perfusion imaging (MPI) and the use of radiation-optimizing 'best practices' worldwide, and to evaluate the relationship between laboratory use of best practices and patient radiation dose. METHODS AND RESULTS: We conducted an observational cross-sectional study of protocols used for all 7911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March-April 2013. Eight 'best practices' relating to radiation exposure were identified a priori by an expert committee, and a radiation-related quality index (QI) devised indicating the number of best practices used by a laboratory. Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤ 9 mSv recommended by guidelines. Laboratory QIs ranged from 2 to 8 (median 5). Both ED and QI differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory QI 6.2). The highest doses (median 12.1 mSv) and low QI (4.9) occurred in Latin America. In hierarchical regression modelling, patients undergoing MPI at laboratories following more 'best practices' had lower EDs. CONCLUSION: Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous opportunities to reduce radiation exposure from MPI globally

Nuclear cardiology practice and associated radiation doses in Europe: results of the IAEA Nuclear Cardiology Protocols Study (INCAPS) for the 27 European countries

PURPOSE: Nuclear cardiology is widely used to diagnose coronary artery disease and to guide patient management, but data on current practices, radiation dose-related best practices, and radiation doses are scarce. To address these issues, the IAEA conducted a worldwide study of nuclear cardiology practice. We present the European subanalysis. METHODS: In March 2013, the IAEA invited laboratories across the world to document all SPECT and PET studies performed in one week. The data included age, gender, weight, radiopharmaceuticals, injected activities, camera type, positioning, hardware and software. Radiation effective dose was calculated for each patient. A quality score was defined for each laboratory as the number followed of eight predefined best practices with a bearing on radiation exposure (range of quality score 0 - 8). The participating European countries were assigned to regions (North, East, South, and West). Comparisons were performed between the four European regions and between Europe and the rest-of-the-world (RoW). RESULTS: Data on 2,381 European patients undergoing nuclear cardiology procedures in 102 laboratories in 27 countries were collected. A cardiac SPECT study was performed in 97.9 % of the patients, and a PET study in 2.1 %. The average effective dose of SPECT was 8.0 ± 3.4 mSv (RoW 11.4 ± 4.3 mSv; P < 0.001) and of PET was 2.6 ± 1.5 mSv (RoW 3.8 ± 2.5 mSv; P < 0.001). The mean effective doses of SPECT and PET differed between European regions (P < 0.001 and P = 0.002, respectively). The mean quality score was 6.2 ± 1.2, which was higher than the RoW score (5.0 ± 1.1; P < 0.001). Adherence to best practices did not differ significantly among the European regions (range 6 to 6.4; P = 0.73). Of the best practices, stress-only imaging and weight-adjusted dosing were the least commonly used. CONCLUSION: In Europe, the mean effective dose from nuclear cardiology is lower and the average quality score is higher than in the RoW. There is regional variation in effective dose in relation to the best practice quality score. A possible reason for the differences between Europe and the RoW could be the safety culture fostered by actions under the Euratom directives and the implementation of diagnostic reference levels. Stress-only imaging and weight-adjusted activity might be targets for optimization of European nuclear cardiology practice