1,507 research outputs found
Facility location decisions within integrated forward/reverse logistics under uncertainty
In this paper, a stochastic mixed integer linear programming (SMILP) model is proposed to optimize the location and size of facilities and service centres in integrated forward and reverse streams under uncertainty. The objective of the model is to minimize establishment, transportation and inventory management costs and simultaneously maximize customer satisfaction with sustainable perspective. The model incorporates different elements and features of distribution networks including inventory management, transportation and establishment of new facilities as well as existing centres. The presented model is the streamlined approach for multi-objective, multi-period, multi-commodity distribution system, and it is supported by a real case study in automobile after sales network. Genetic algorithm is implemented to solve the model in reasonable time. The performance of the model and the effects of uncertainty on provided solution are studied under different cases. Competitive result of the stochastic model compared to deterministic model ensures that the proposed approach is valid to be applied for decision making under uncertainty.Scopu
Interseeded cover crops, soil health, and nitrogen supply for grain corn in Ontario
Non-Peer ReviewedInterseeded cover crops are a promising option for improving environmental sustainability in corn-based rotations. Field plots were established in 2015 under conventional tillage and regional corn N fertilization practices and repeated over two seasons at three sites in southern Ontario: Ridgetown, Elora, and Peterborough. The objectives were to evaluate the effects of interseeded annual ryegrass (ARG) and red clover (RCL) on grain corn yield and N uptake; soil mineral N (Nmin); and soil biological parameters. At each site, ARG, RCL, an ARG/RCl blend (MIX), and a no-cover control (BARE) were arranged in a RCBD replicated four times. The cover crops were seeded between the corn rows at the 5-leaf stage using an InterSeederTM drill. Cover crops accumulated 15 - 860 kg C ha-1 and 1.3 - 77 kg N ha-1 per season, and their yields were significantly correlated with soil microbial biomass, β-Glucosidase activity, and particulate organic matter. Community-level physiological profiling (BIOLOG EcoplatesTM) showed that microbial community diversity was significantly greater in ARG than BARE. Grain N concentration (10.8 - 11.2 g kg-1) and aboveground corn N uptake (100 - 154 kg ha-1) were not significantly reduced by cover crops at all sites. Although residual Nmin levels measured at grain corn harvest (0-30 cm) and the following spring (0-15 cm) were generally low (2.4 - 9.3 mg kg-1) at all sites, ARG had 48% lower Nmin than BARE. The effects of cover crops on soil health parameters, corn N uptake and Nmin were more affected by site and seasonal variability than by cover crop treatments. However, the results indicate the potential for improving soil health when there is successful establishment of interseeded annual ryegrass or red clover
Monthly direct and indirect greenhouse gases emissions from household consumption in the major Japanese cities
Urban household consumption contributes substantially to global greenhouse gases (GHGs) emissions. Urban household emissions encompass both direct and indirect emissions, with the former associated with the direct use of fossil fuels and the latter with the emissions embodied in the consumed goods and services. However, there is a lack of consistent and comprehensive datasets outlining in great detail emissions from urban household consumption. To bridge this data gap, we construct an emission inventory of urban household emissions for 52 major cities in Japan that covers around 500 emission categories. The dataset spans from January 2011 to December 2015 and contains 12,384 data records for direct emissions and 1,543,128 records for indirect emissions. Direct emission intensity is provided in g-CO2/JPY to facilitate both future studies of household emission in Japan, as well as act as a reference for the development of detailed household emission inventories in other countries
Returnable transport packaging in developing countries: drivers,barriers and business performance
This study, drawing on natural resource-based view, identifies drivers, barriers and the potential benefits of returnable transport packaging (RTP) – that is, the repeated use of packaging items – and conceptualises RTP as a technology and resource that supports organisational competitiveness. Specifically, it investigates the impact of RTP adoption on business performance, the effects of drivers, barriers and size of organisations. The data collection took place in Nigeria and South Africa. The findings suggest that RTP has a significant positive impact on business performance. Whilst prior studies seem to suggest that shrinkage and attrition are the major problems identified with the usage of RTP, our findings indicate that there are several other barriers affecting RTP adoption and the resultant performance advantage. The results also show that there is an increasing move towards adoption of RTP but some organisations are faced with financial constraints, especially the small and medium size enterprises. In addition, the results show that RTP is largely a ‘sustainability facing’ initiative with adopters motivated primarily by potential environmental, economic, social and operational benefits of adoption
Delay causes analysis in complex construction projects; a Semantic Network Analysis approach
Delays are among the most crucial adversaries to the success and performance of construction projects, making delay analysis and management a critical task for project managers. This task will be highly complicated in large-scale projects such as construction, which usually consist of a complex network of heterogeneous entities in continuous interaction. Traditional approaches and methods for the analysis of delays and their causes have been criticised for their ability to handle complex projects, and for considering the interrelationships between delay causes. Addressing this gap, this research introduces an alternative approach for delay causes analysis by adopting Semantic Network Analysis (SNA) method. The paper reports the results from an investigation of delays in construction projects in the Oil-Gas-Petrochemical sector using SNA. The method’s capacity to identify and rank delay causes, which can assist managers in selecting appropriate measures for eliminating them, are empirically examined and discussed. The paper argues that SNA leads to a more comprehensive understanding of the main causes of delay in large and complex projects, allowing a better identification and mapping of the interrelationships between these discrete factors
Design of microresonators to minimize thermal noise below the standard quantum limit
Microfabricated resonators play a crucial role in the development of quantum measurement, including future gravitational wave detectors. We use a micro-genetic algorithm and a finite element method to design a microresonator whose geometry is optimized to maximize the sub-Standard Quantum Limit (SQL) performance including lower thermal noise (TN) below the SQL, a broader sub-SQL region, and a sub-SQL region at lower frequencies. For the proposed design, we study the effects of different geometries of the mirror pad and cantilever microresonator on sub-SQL performance. We find that the maximum ratio of SQL to TN is increased, its frequency is decreased, and the sub-SQL range is increased by increasing the length of the microresonator cantilever, increasing the radius of the mirror pad, decreasing the width of the microresonator cantilever, and shifting the laser beam location from the mirror center. We also find that there exists a trade-off between the maximum ratio of SQL to TN and the sub-SQL bandwidth. The performance of this designed microresonator will allow it to serve as a test-bed for quantum non-demolition measurements and to open new regimes of precision measurement that are relevant for many practical sensing applications, including advanced gravitational wave detectors
Therapeutic potential of allicin-rich garlic preparations: Emphasis on clinical evidence toward upcoming drugs formulation
Garlic has been used for a long time in human history. Allicin, the main active compound present in freshly injured garlic, is enzymatically formed from alliin. Allicin has shown doubtless beneficial effects and even be conceived as medicine. The present review highlights allicin-associated studies. Indeed, clinical studies on healthy subjects have evidenced that standardized garlic treatment (900 mg/day) significantly reduces total cholesterol (TC) and low-density lipoprotein cholesterol (c-LDL). Besides, allicin also led to a marked improvement in mouth opening, burning sensation, and oral health-related quality of life on stage II oral submucous fibrosis patients. Interestingly, in children, allicin also has been proposed for thrush prevention and as an alternative antibiotic therapy. Nonetheless, there is particular attention to allicin bioavailability, given its high instability. Although clinical evidence has promoted allicin release from garlic powder tablets under simulated gastrointestinal conditions, garlic tablets are those that have provided less alliinase protection due to its fast disintegration, releasing low allicin amounts.Natália Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and "NORTE2020-Programa Operacional Regional do Norte" (NORTE-01-0145-FEDER-000012)
The effect of on-site and outreach-based needle and syringe programs in people who inject drugs in Kermanshah, Iran
Background: Needle and syringe programs (NSPs) are widely used to reduce harms associated with drug injecting. This study assessed the effect of facility-based (on-site services at drop-in centre) and outreach models of NSP on injection risk behaviours. Methods: Self-reported data from 455 people who injected drugs (PWID) during 2014 in Kermanshah, Iran, were examined to measure demographic characteristics and risk behaviors. Self-reported and program data were also assessed to identify their main source of injection equipment. Participants were divided into three sub-groups: facility-based NSP users, outreach NSP users and non-users (comparison group). Coarsened exact matching was used to make the three groups statistically equivalent based on age, place of residence, education and income, and groups were compared regarding the proportion of borrowing or lending of syringes/cookers, reusing syringes and recent HIV testing. Results: Overall, 76% of participants reported any NSP service use during the two months prior to interview. Only 23% (95%CI: 17-27) reported outreach NSP as their main source of syringes. Using facility-based NSP significantly decreased recent syringe borrowing (OR: 0.27, 95%CI: 0.10-0.70), recent syringe reuse (OR: 0.38, 95%CI: 0.23-0.68) and increased recent HIV testing (OR: 2.60, 95%CI: 1.48-4.56). Similar effects were observed among outreach NSP users; in addition, the outreach NSP model significantly reduced the chance of lending syringes (OR: 0.31, 95%CI: 0.15-0.60), compared to facility-based NSP (OR: 1.25, 95%CI: 0.74-2.17). Conclusion: These findings suggest that the outreach NSP model is as effective as facility-based NSP in reducing injection risk behaviours and increasing the rate of HIV testing. Outreach NSP was even more effective than facility-based in reducing the lending of syringes to others. Scaling up outreach NSP is an effective intervention to further reduce transmission of HIV via needle sharing
Client-Level Coverage of Needle and Syringe Program and High-Risk Injection Behaviors: A Case Study of People Who Inject Drugs in Kermanshah, Iran
Background: Needle-syringe programs (NSP) have been running in Iran since 2002. However, the coverage of such program among the NSP clients at the individual level was not studies yet. This study aimed to determine the client coverage of NSP and its correlation with high injection-related risk behaviors. Methods: A cross-sectional survey was conducted in Kermanshah province, Iran, in 2014. 230 people who inject drugs (PWID) recruited from two drop-in centers (DICs) from April to September 2014, participated in a face-to-face interview to provide information related individual coverage of NSP, demographic characteristics, and injecting behaviors 30 days prior to the interview. Findings: Overall, the average of syringe coverage was 158% [95% confidence interval (CI) = 65.7-205.5], while 56% (95% CI = 40-97) have individual converge less than 100%. Needle/syringe sharing was significantly higher among individual with low NSP coverage [adjusted odds ratio (AOR) = 2.6, 95% CI = 1.3-6.2]. About 85% participants with coverage of less than 100% reported reuse of syringe within the last 30 days (AOR = 3.2, 95% CI = 1.4-7.7). Conclusion: PWID are different regarding their NSP individual-level converges. There are certain clusters of PWID, who do not receive sufficient number of syringes. Given that insufficient individual syringe coverage level is highly associated with injection risk behaviors, reasons for such low converge need to be assessed and addressed carefully
- …