756 research outputs found

    Sanitation as a Business: Unclogging the Blockages

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    The first Unclogging the Blockages conference took place in Kampala, Uganda in February 2014 with the aim of putting on the table some of the major challenges facing the scale up of sustainable sanitation as well as collaborating towards innovaive soluions. This report summarizes the discussions and takeaway messages from the conference, including concrete action plans developed around a number of thematic areas. [KEY FINDINGS]Market based approaches are key to addressing some of the main barriers for scaling sustainable sanitation solutions. Participants came away with a much richer understanding of the principles and key tenets of sanitation as a business. A push for greater integration in sanitation programming between the housing, energy, business, health, and education sectors will allow for sustainable city and district-wide sanitation services.Unlocking finance for businesses and households and embedding monitoring within all work is critical. One interesting outcome of the group work was a suggestion to form a Global Sanitation Financing Alliance.Supporting sanitation businesses to be successful in the realities of the market requires on-the-ground, real time, market-focused technology development and R&D. A variety of these technologies were on display at the meeting

    Application of Differential Scanning Calorimetry to Characterize Thin Film Deposition Processes

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    With the recent increase in awareness on the environmental impact of industrial coating processes, chromate-based coating processes have been elevated to the rank of the technologies targeted by the EPA for rapid replacement by environmentally friendly processes. Therefore, there is a clear need for advances in coating technologies to identify alternative industrial practices. This thesis characterizes a process developed at Cleveland State University as an alternative deposition technique to generate uniform coatings onto solid substrates. A kinetic analysis to extract scale up parameters involved in the reaction kinetics leading to high-performance coatings is demonstrated in this research. The work consists of thermal characterization of deposition experiments using Modulated Differential Scanning Calorimeter (MDSC), complemented with preliminary finite-element-modeling (FEM) of fluid flow and transport phenomena in the vicinity of the deposition assembly. MDSC is capable of using linear and modulated heating rates. Modulation over imposes a sinusoidal heating profile to a linear heating rate. Therefore, modulation combines two conventional DSC experiments into one. Modulation provides the ability to differentiate reversibility from irreversibility in transitions. This study intends to study both the advantages and disadvantages of the modulation compared to conventional DSC in the analysis of thin film deposition. A protocol to analyze deposition reaction kinetics using a conventional DSC was formulated in this research. While modulation was unable to produce results that could be compared to the conventional DSC, further in-depth studies need to be completed. This research outlines the experimental procedure to analyze deposition reactions via conventional DSC, and a kinetic analysis procedure to extract reaction kinetics is demonstrated. This research successfully demonstrated that the deposition mechanism can be characterized via DSC experiments. Further studies are anticipated to lead to scale-up criter

    Policy evaluation and design in the light of rational expectations

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    This thesis examines certain key problems that the existence of forward rational expectations poses for policy analysis. The separate stages of estimating, testing and solving an econometric model are dealt with in turn. The main body of original work is in chapters four and six. In chapter four the problem of the existence of a continuum of solutions to a rational expectations model is addressed. We show that the existing practice of imposing terminal conditions is arbitrary and a procedure is advanced which in principle at least, can be used to estimate the solution jointly with the parameters. In chapter six analytical closed forms for the first order conditions of the likelihood function of the endogenous variables of a general rational expectations model are derived. We believe this is a major contribution to the literature because it opens the door to computationally efficient and cheap likelihood estimation, something not previously available. The first order conditions for a class of models with no predetermined variables has been programmed in Fortran IV and this has been used in chapter seven to estimate a model of financial asset demands. A likelihood ratio test of restrictions implied by rational expectations is comfortably passed so establishing empirical support for the hypothesis. Other original work in the thesis is contained in chapter five. Here we scrutinise the validity of a simulation technique advanced by Fair and Anderson which it is claimed solves a standard non rational model to yield an approximate rational expectations solution. The results of the chapter suggest the method is better in certain circumstances than in others and these circumstances pertain to the make up of the model in question. Finally, chapters two and three cast a critical eye over the policy analysis literature to which a minor contribution is made

    Excessive functions of continuous time Markov chains

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    AbstractWe consider transient continuous time Markov chains P(t) with P′ij(0)=qiΠij for i≠j and −qi for i=j. We assume 0<qi<∞ for all i. Then 1/qi is the mean time the process remains in state i, and Π is the transition matrix of the imbedded jump process. We let q be a diagonal matrix with diagonal entries qi.A non-negative function h is P(t)-excessive (invariant) if h≥P(t)h, (h=P(t) h) for all t. It is Π-superregular (regular) if h≥Πh (h=Πh). Our main results characterize the excessive functions of the minimal process in terms of q and Π. These results can also be used to characterize excessive functions of certain non-minimal processes

    Entrainment Mechanisms for Outflows in the L1551 Star-Forming Region

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    We present high sensitivity 12CO and 13CO J=1!0 molecular line maps covering the full extent of the parsec scale L1551 molecular outflow, including the redshifted east-west (EW) flow. We also present 12CO J=3!2 data that extends over a good fraction of the area mapped in the J=1!0 transition. We compare the molecular data to widefield, narrow-band optical emission in H. While there are multiple outflows in the L1551 cloud, the main outflow is oriented at 50â—¦ position angle and appears to be driven by embedded source(s) in the central IRS 5 region. The blueshifted outflowing molecular gas extends to the edge of the molecular cloud and beyond the last HH object, HH 256. On the contrary, the redshifted molecular gas terminates within the cloud, short of the most distant HH object, HH 286, which lies well beyond the cloud boundary. The J=3!2 data indicate that there may be molecular emission associated with the L1551 NE jet, within the redshifted lobe of main outflow. We have also better defined the previously known EW flow and believe we have identified its blueshifted counterpart. We further speculate that the origin of the EW outflow lies near HH 102. We use velocity dependent opacity correction to estimate the mass and the energy of the outflow. The resulting mass spectral indices from our analysis, are systematically lower (less steep) than the power law indices obtained towards other outflows in several recent studies that use a similar opacity correction method. We show that systematic errors and biases in the analysis procedures for deriving mass spectra could result in errors in the determination of the power-law indices. The mass spectral indices, the morphological appearance of the position-velocity plots and integrated intensity emission maps of the molecular data, compared with the optical, suggest that jet-driven bow-shock entrainment is the best explanation for the driving mechanism of outflows in L1551. The kinetic energy of the outflows is found to be comparable to the binding energy of the cloud and sufficient to maintain the turbulence in the L1551 cloud

    Ultrasonically assisted emulsion polymerisation

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    CERTIFICATION REPORT: The certification of the mass fractions of cadmium copper, manganese and nickel in dark chocolate: ERM BD512

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    This report describes the production of ERM-BD512, which is a matrix material certified for the mass fraction of cadmium, copper, manganese and nickel. This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. The CRM was produced from commercially available dark chocolate produced in Peru. About 15 kg of chocolate bars were melted, the melt was homogenised and cast into moulds to produce pellets of about 0.5 g. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. Within-unit homogeneity was quantified to determine the minimum sample intake. The certified mass fraction of Cd was obtained by measurement, using the technique of isotope dilution ICP MS. The mass fractions of Cu, Mn and Ni were obtained by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025:2005. Technically invalid results were removed but no outliers were eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for quality control and assessment of method performance. As with any reference material, it can be used for establishing control charts or validation studies. The CRM is available in packages of 6 glass vials, each containing a single pellet of about 0.5 g, which were sealed under an atmosphere of argon. The minimum amount of sample to be used is 250 mg. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.F.6-Reference Material
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