2,139 research outputs found

    Design and development of a modified spouted bed coater for the micro-encapsulation of powders : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Chemical Technology, Massey University

    Get PDF
    A modified spouted bed coater was designed and constructed for the micro-encapsulation of solid particles. The coating of small particles with a polymer film can alter physical factors such as taste and release rate. These properties are particularly important in the field of pharmacology as the nature of the coating can be changed to prolong or target drug release based on physiological conditions such as pH and time. The spouted bed coater was modified to induce gas and particle recirculation through a draft tube containing a venturi to increase droplet and particle mixing, while a high velocity gas jet and large diameter draft tube promotes the recirculation of gas and solid within the apparatus. The effectiveness of the design was tested in terms of gas and solid mass flows through the draft tube using a venturi within the draft tube and an induction detector to measure the mass flow. To determine the effectiveness of the coater design in terms of coalescence and the influence of operational variables, a factorial experiment was conducted. The result of this experiment showed that the coalescence of particles was dominated by the relative humidity in the apparatus which was unable to be directly related to the operational variables. The capacity to micro-encapsulate particles was demonstrated by coating fine table salt with an acrylic polymer Eudragit NE 40D in combination with bentonite clay as a free flow agent or glident. The results of this trial showed the distribution of polymer/clay and the reduction in dissolution rate as a function of particle size

    Geochemical studies on colloidal and macromolecular constituents in surface waters

    Get PDF
    Imperial Users onl

    Nuevo Amanecer Phase - IV

    Get PDF
    Studio boards consist of 3 single page pdf files.Farmworker Housing: Theory and design of housing for migrant farm workers in rural Oregon. Creating a new collaborative community so close to the core of Woodburn, it is important for the residents of Nuevo Amanacer IV to have an identity of their own, while acnowledging the surrounding community. The units are sized to be similar in street dimension to the other homes along second street. The hight and density is kept lower near the street and rises up along the east and northern edges of the site. The open courtyard encourages the neighbors to use the site and interact with its residents

    Social Interactions in the Labor Market

    Get PDF
    We examine theoretically and empirically social interactions in labor markets and how policy prescriptions can change dramatically when there are social interactions present. Spillover effects increase labor supply and conformity effects make labor supply perfectly inelastic at a reference group average. The demand for a good may also be influenced by either a spillover effect or a conformity effect. Positive spillover increases the demand for the good with interactions, and a conformity effect makes the demand curve pivot to become less price sensitive. Similar social interactions effects appear in the associated derived demands for labor. Individual and community factors may influence the average length of poverty spells. We measure local economic conditions by the county unemployment rate and neighborhood spillover effects by the racial makeup and poverty rate of the county. We find that moving an individual from one standard deviation above the mean poverty rate to one standard deviation below the mean poverty rate (from the inner city to the suburbs) lowers the average poverty spell by 20–25 percent. We further consider overall labor market outcomes by examining theoretically the socially optimal wealth distribution. Interdependence in utility can mitigate the need to transfer wealth to low-wage individuals and may require them to be poorer by all objective measures. Finally, we quantify how labor market policy changes when there are household social interactions. Labor supply estimates indicate positive economically important spillovers for adult U.S. men. Ignoring or incorrectly considering social interactions can mis-estimate the labor supply response of tax reform in the United States by as much as 60 percent.social interactions, spillover, conformity, inequality, poverty, labor supply, reference group, social multiplier, income tax, PSID

    A rapid-acquisition electrical time-domain reflectometer for analysis of time-variant impedance discontinuities

    Get PDF
    A distributed crack sensor has been developed for the measurement of cracks in concrete structures. The sensor is measured using a distributed measurement technique known as electrical time-domain reflectometry (ETDR). ETDR has traditionally been used to measure time-invariant (i.e. unchanging with time) impedance discontinuities, however applications of the sensor in structural failure analysis require measurement of time-variant (i.e. changing with time) impedance discontinuities at rates as high as 10 k measurements per second. ETDR is a suitable measurement technique for these applications since a time-domain reflectometer (TDR) acquisition can be performed in less than 100 µs. Employment of ETDR in these applications, however, requires a TDR that supports measurement rates as high as 10 k measurements per second. Commercial TDRs are not suitable for these applications since their measurement rates are typically less than 10 measurements per second. In order to satisfy the high measurement rates required for these applications, a rapid-acquisition TDR was developed that supports measurement rates as high as 10.1725 k measurements per second. The acquisition rate of the TDR was evaluated by modulating the voltage reflected from a short termination with a voltage variable attenuator. The TDR was able to monitor the reflected voltage at modulation frequencies as high as 1 kHz. The TDR was applied in the monitor of a crack sensor embedded in a bridge column during a shake-table experiment. The TDR was able to monitor the evolution of a crack which formed in the column during the experiment. The operation, design, evaluation, and application of the TDR are discussed herein --Abstract, page iii

    Tariff-Rate Quotas : Difficult to model or plain simple?

    Get PDF
    The difficulty of reliably and accurately incorporating tariffrate quotas (TRQs) into trade models has received a lot of attention in recent years. As a result of the Uruguay Round of GATT negotiations, TRQs replaced an assortment of tariff and nontariff instruments in an effort to standardise trade barriers, and facilitate their future liberalisation. Understanding the nuances of TRQs is now particularly crucial for New Zealand because of the preferential access arrangements that New Zealand has for a number of products in highly protected markets such as the European Union, Japan, and the United States. It has been argued that TRQs are complex instruments and are difficult to model because for any trade flow between two countries, one of three regimes may be applicable : 1. The import quota may not be binding and the within-quota tariff applies; 2. The quota may be binding, the within-quota tariff applies, and a quota rent is created; or 3. Trade occurs over and above the quota, in which case an over-quota tariff applies (although, even in this regime, someone is still able to collect the quota rent on within-quota trade). But even this characterisation, which many claim is too complex to model, is a major simplification of reality. Bilateral preferences are ubiquitous, and such preferences are usually included in the determination of multilateral market access quotas. It is usual, therefore, that the TRQ instrument has several tiers to the quota schedule, plus a number of within and over-quota tariff rates applicable on either a bilateral or a multilateral basis. Further trade liberalisation creates something of a dilemma for New Zealand. Any decrease in over-quota tariffs and/or increase in quota levels potentially reduces the value of quota rents, many of which accrue to New Zealand due to the bilateral preferences. It is important, therefore, that New Zealand trade negotiators understand how much additional trade is required to offset the loss of New Zealands quota rents. Modelling trade in the presence of TRQs is the only way to ascertain this knowledge. The purpose of this paper is to show that complex TRQs can be modelled very easily and precisely. The only catch is that the model must be formulated as a complementarity problem rather than the more conventional linear or nonlinear optimisation problem. The concept will be demonstrated using a simple 3-region, single commodity spatial price equilibrium model of trade.Tariff-rate quota, trade modelling, mathematical programming, complementarity

    How can Health Technology Project Communications be Improved in a Hospital

    Get PDF
    Healthcare professionals have had many challenges related to communication. Some of these challenges are related to health information technology, project management, and change management. This research addresses facilitators and barriers that healthcare providers have encountered in projects completed at the survey site. The integration of technology to support interdisciplinary teams transitioning to patient centered care requires enhanced focus on Project Communication as a key component of successful Health Information Technology (HIT) projects. Professional and organizational cultures in health care must transform to promote improved patient care
    • …
    corecore