134,715 research outputs found

    Wastewater disposal to landfill-sites: a synergistic solution for centralized management of olive mill wastewater and enhanced production of landfill gas

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    The present paper focuses on a largely unexplored field of landfill-site valorization in combination with the construction and operation of a centralized olive mill wastewater (OMW) treatment facility. The latter consists of a wastewater storage lagoon, a compact anaerobic digester operated all year round and a landfill-based final disposal system. Key elements for process design, such as wastewater pretreatment, application method and rate, and the potential effects on leachate quantity and quality, are discussed based on a comprehensive literature review. Furthermore, a case-study for eight (8) olive mill enterprises generating 8700 m(3) of wastewater per year, was conceptually designed in order to calculate the capital and operational costs of the facility (transportation, storage, treatment, final disposal). The proposed facility was found to be economically self-sufficient, as long as the transportation costs of the OMW were maintained at <= 4.0 (sic)/m(3). Despite that EU Landfill Directive prohibits wastewater disposal to landfills, controlled application, based on appropriately designed pre-treatment system and specific loading rates, may provide improved landfill stabilization and a sustainable (environmentally and economically) solution for effluents generated by numerous small- and medium-size olive mill enterprises dispersed in the Mediterranean region

    Producer Support Estimates (PSEs) for agriculture in developing countries

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    In many developing countries, governments rely on price-based measures (including border protection and subsidies on inputs and outputs) more than on budgetary payments to achieve agricultural policy objectives defined to include price stabilization or food self-sufficiency. Assessing the effects of these price-based measures is thus important to evaluating whether agriculture is being protected or disprotected by commodity or in the aggregate. This aspect of producer support estimates (PSEs) is simple to describe conceptually but difficult to evaluate well empirically. Developing countries may face higher international transport and port costs for imports and exports than developed countries or may have substantial internal handling, transportation and processing costs. Separating these structural effects on farmers from agricultural policy effects that drive a wedge between the domestic farmgate price and an adjusted international reference price requires extensive data and judgments. In this paper, we describe the PSE measurement issues and illustrate their importance. We estimate product-specific market price support, budget expenditures and PSEs for three important agricultural commodities (wheat, rice and corn) in India (1985-2002), using representative disaggregated state-level results, and for five commodities (wheat, rice, corn, soybeans and sugar) in China (1995-2001). The results for India suggest that ignoring factors such as internal transport costs, marketing margins and quality differences can result in inaccurate price support estimates and PSEs that may be of the wrong sign. We also explore how relaxing or changing certain standard PSE assumptions (such as altering the “scaling up” procedure or computing the PSE as a percentage of value of production at world reference prices) can have large impacts on the results. Finally, for commodities that are near self-sufficiency, we follow Byerlee and Morris (1993) and define a relevant adjusted reference price based on the relationship between an estimated autarky price and the import and export prices. We discuss this procedure and use the resulting reference prices to compute the market price support component of the PSE for India. Based on our three-commodity PSEs for India, support is largely counter-cyclical, rising when world prices are low (as in the late 1980s and 1990s) and falling when world prices strengthen (as in the mid 1990s). From our more preliminary five-commodity PSE estimates for China, a trend decline in disprotection is more evident. Further research is needed to confirm and elaborate on these results.

    Measurement and valuation of health providers' time for the management of childhood pneumonia in rural Malawi - An empirical study

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    Background: Human resources are a major cost driver in childhood pneumonia case management. Introduction of 13-valent pneumococcal conjugate vaccine (PCV-13) in Malawi can lead to savings on staff time and salaries due to reductions in pneumonia cases requiring admission. Reliable estimates of human resource costs are vital for use in economic evaluations of PCV-13 introduction. Methods: Twenty-eight severe and twenty-four very severe pneumonia inpatients under the age of five were tracked from admission to discharge by paediatric ward staff using self-administered timesheets at Mchinji District Hospital between June and August 2012. All activities performed and the time spent on each activity were recorded. A monetary value was assigned to the time by allocating a corresponding percentage of the health workers' salary. All costs are reported in 2012 US.Results:Atotalof1,017entries,groupedaccordingto22differentactivitylabels,wererecordedduringtheobservationperiod.Onaverage,99min(standarddeviation,SD=46)werespentoneachadmission:93(SD=38)forsevereand106(SD=55)forveryseverecases.Approximately40. Results: A total of 1,017 entries, grouped according to 22 different activity labels, were recorded during the observation period. On average, 99 min (standard deviation, SD = 46) were spent on each admission: 93 (SD = 38) for severe and 106 (SD = 55) for very severe cases. Approximately 40 % of activities involved monitoring and stabilization, including administering non-drug therapies such as oxygen. A further 35 % of the time was spent on injecting antibiotics. Nurses provided 60 % of the total time spent on pneumonia admissions, clinicians 25 % and support staff 15 %. Human resource costs were approximately US 2 per bed-day and, on average, US29.5perseverepneumoniaadmissionandUS 29.5 per severe pneumonia admission and US 37.7 per very severe admission. Conclusions: Self-reporting was successfully used in this context to generate reliable estimates of human resource time and costs of childhood pneumonia treatment. Assuming vaccine efficacy of 41 % and 90 % coverage, PCV-13 introduction in Malawi can save over US$ 2 million per year in staff costs alone

    Post-Foreclosure Community Stabilization Strategies: Case Studies and Early Lessons 2008

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    In the midst of all the foreclosures sweeping the country, and the turmoil on Wall Street, nonprofit housing organizations are quietly going about the work of stabilizing communities hard hit by the crisis. Most have had frontline responsibility for counseling families threatened with foreclosure. With their assistance tens of thousands of families have restructured their budgets, negotiated with servicers to modify their loans, and saved their homes. Other families, too far along in the foreclosure process to stop it from happening, have received help transitioning to new housing arrangements.While the work with distressed homeowners must continue, nonprofits are feeling increased pressure to deal with the growing foreclosed housing stock. These units are causing incalculable harm to neighborhoods, and any hope of housing recovery must ensure that these units are swiftly put back into productive use or demolished. This collection of 14 case studies outlines strategies that nonprofit organizations across the country are using to begin the process of repairing damaged communities.The stakes are enormous. Vacant housing invites vandalism, and becomes a hub for gangs and crime. Virtually all case study subjects reported that, within weeks of housing becoming vacant, thieves break into the units and strip them of their valuable copper plumbing and wiring, heedless of any destruction they leave in their wake. In Phoenix a half-finished, abandoned subdivision was used as an informal "Home Depot" as other homeowners broke in and helped themselves to fixtures and appliances. In Cleveland, vandals remove not just the copper but the aluminum siding from vacant houses. In photos these houses have a desolate, post-disaster look, like the aftermath of a hurricane. When units get demolished the vacant lots soon sprout grass and trash, adding to the community's forlorn appearance.Vacant, deteriorated units place a downward pressure on housing values that puts nearby neighbors in a bind. In order to sell their units they will have to reduce the price, as no one will pay top dollar to live in a blighted neighborhood. Yet their ability to refinance into a more affordable mortgage may be compromised by the drop in property values; in some cases this leads to additional foreclosures and the downward cycle continues.Intervening in these troubled neighborhoods is challenging. In some markets housing prices are still falling, making it hard to determine the value of the units. Bank asset managers and servicers often lack detailed knowledge of the markets, or even of the units they have in their own inventory. This leads them to overvalue their properties and hold out for more than they are worth, delaying the process of acquiring and renovating them for resale to new homebuyers. Finally, the complex ownership structure of mortgages which were rolled into collateralized debt obligations and other investment vehicles makes it very difficult to establish who owns properties and who has authority to negotiate their sale.0

    Emergency Tenant Protection in New York: Ten Years of Rent Stabilization

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    New York City\u27s rent stabilization system was designed as an alternative to the rent control system. Rent stabilization looked to the owners for supervision as a way to benefit not only the system but tenants through an informed and experienced administration. Unfortunately, the system has had its fair share of shortcomings as rules have become technical, complex, and ill equipped to address the concerns of tenants. This comment examines the stabilization system\u27s history and its current status. Though the current system has flaws, the flaws can be fixed and must be to protect NYC tenants and owners

    Universal Loop-Free Super-Stabilization

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    We propose an univesal scheme to design loop-free and super-stabilizing protocols for constructing spanning trees optimizing any tree metrics (not only those that are isomorphic to a shortest path tree). Our scheme combines a novel super-stabilizing loop-free BFS with an existing self-stabilizing spanning tree that optimizes a given metric. The composition result preserves the best properties of both worlds: super-stabilization, loop-freedom, and optimization of the original metric without any stabilization time penalty. As case study we apply our composition mechanism to two well known metric-dependent spanning trees: the maximum-flow tree and the minimum degree spanning tree

    Model Predictive Control Based Trajectory Generation for Autonomous Vehicles - An Architectural Approach

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    Research in the field of automated driving has created promising results in the last years. Some research groups have shown perception systems which are able to capture even complicated urban scenarios in great detail. Yet, what is often missing are general-purpose path- or trajectory planners which are not designed for a specific purpose. In this paper we look at path- and trajectory planning from an architectural point of view and show how model predictive frameworks can contribute to generalized path- and trajectory generation approaches for generating safe trajectories even in cases of system failures.Comment: Presented at IEEE Intelligent Vehicles Symposium 2017, Los Angeles, CA, US
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