994 resultados para Quality Upgrading


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In this study, we examine the effects of tariff reduction on firms' quality upgrading by employing an Indonesian plant-product-level panel dataset matched with a plant-level dataset. We explore the effects of lower output and input tariffs separately, by focusing on the apparel industry. By estimating the Berry-type demand function, we derive product-quality indicators based on the Khandelwal (Review of Economic Studies, 2010) methodology, which enables us to isolate quality upgrading from changes in prices. Our findings are as follows. First, a reduction in output tariffs does not affect product quality upgrading. Second, a reduction in input tariffs boosts quality upgrading in general. In particular, this impact is greater for import firms, which is consistent with the fact that the source of the boost is the import of high-quality foreign inputs.

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In the 1980s Butler adapted the life cycle product model to the tourism industry and created the “Tourism Area Life Cycle (TALC) model”. The model recognizes six stages in the tourism product life cycle: exploration, investment, development, consolidation, stagnation and followed, after stagnation, by decline or revitalization of the product. These six stages can in turn be regrouped into four main stages. The Butler model has been applied to more than 30 country cases with a wide degree of success. De Albuquerque and Mc Elroy (1992) applied the TALC model to 23 small Caribbean island States in the 1990s. Following De Albuquerque and Mc Elroy, the TALC is applied to the 32 member countries of the Caribbean Tourism Organization (CTO) (except for Cancun and Cozumel) to locate their positions along their tourism life-cycle in 2007. This is done using the following indicators: the evolution of the level, market share and growth rate of stay-over arrivals; the growth rate and market share of visitor expenditures per arrival and the tourism styles of the destinations, differentiating between ongoing mass tourism and niche marketing strategies and among upscale, mid-scale and low-scale destinations. Countries have pursued three broad classes of strategies over the last 15 years in order to move upward in their tourism life cycle and enhance their tourism competitiveness. There is first a strategy that continues to rely on mass-tourism to build on the comparative advantages of “sun, sand and sea”, scale economies, all-inclusive packages and large amounts of investment to move along in Stage 2 or Stage 3 (Cuba, Dominican Republic, Puerto Rico). There is a second strategy pursued mainly by very small islands that relies on developing specific niche markets to maintain tourism competitiveness through upgrading (Anguilla, Antigua and Barbuda, British Virgin Islands and Turks and Caicos), allowing them to move from Stage 2 to Stage 3 or Stage 3 to a rejuvenation stage. There is a third strategy that uses a mix of mass-tourism, niche marketing and quality upgrading either to emerge onto the intermediate stage (Trinidad and Tobago); avoid decline (Aruba, The Bahamas) or rejuvenate (Barbados, Jamaica and the United States Virgin Islands). There have been many success stories in Caribbean tourism competitiveness and further research should aim at empirically testing the determinants of tourism competitiveness for the region as a whole.

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The aim of this dissertation is to examine, model and estimate firm responses to

demand shocks by focusing on specific industries where demand shocks are well

identified. Combining reduced-form evidence and structural analysis, this dissertation

extends the economic literature by focusing on within-firm responses of firms

to two important demand shocks that are identifiable in empirical settings. First,

I focus on how firms respond to a decrease in effective demand due to competition

shocks coming from globalization. By considering China's accession to the World

Trade Organization in 2001 and its impact on the apparel industry, the aim of these

chapters is to answer how firms react to the increase in Chinese import competition,

what is the mechanism behind these responses, and how important they are in explaining

the survival of the Peruvian apparel industry. Second, I study how suppliers'

survival probability relates to the sudden disruption of their main customer-supplier

relationships with downstream manufacturers, conditional on suppliers' own idiosyncratic

characteristics such as physical productivity.

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A good working environment will help to provide the user with a good sense of wellbeing, inspiration and comfort. The main advantages of good environments is in terms of reduced upgrading investment, reduced sickness absence, an optimum level of productivity and improved overall satisfaction. Individuals respond very differently to their environments and research suggests a correlation between worker productivity and well-being, environmental, social and organisational factors. Research shows the occupants who report a high level of dissatisfaction about their job are usually the people who suffer more work and office environment related illnesses which affect their wellbeing, but not always so. Well-being expresses overall satisfaction. There is a connection between dissatisfied staff and low productivity; and a good sense of well-being is very important as it can lead to substantial productivity gain. If the environment is particularly bad people will be dissatisfied irrespective of job satisfaction. This paper describes research showing how environment affects productivity.

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The Michigan Department of Transportation is evaluating upgrading their portion of the Wolverine Line between Chicago and Detroit to accommodate high speed rail. This will entail upgrading the track to allow trains to run at speeds in excess of 110 miles per hour (mph). An important component of this upgrade will be to assess the requirement for ballast material for high speed rail. In the event that the existing ballast materials do not meet specifications for higher speed train, additional ballast will be required. The purpose of this study, therefore, is to investigate the current MDOT railroad ballast quality specifications and compare them to both the national and international specifications for use on high speed rail lines. The study found that while MDOT has quality specifications for railroad ballast it does not have any for high speed rail. In addition, the American Railway Engineering and Maintenance-of-Way Association (AREMA), while also having specifications for railroad ballast, does not have specific specifications for high speed rail lines. The AREMA aggregate specifications for ballast include the following tests: (1) LA Abrasion, (2) Percent Moisture Absorption, (3) Flat and Elongated Particles, (4) Sulfate Soundness test. Internationally, some countries do require a highly standard for high speed rail such as the Los Angeles (LA) Abrasion test, which is uses a higher standard performance and the Micro Duval test, which is used to determine the maximum speed that a high speed can operate at. Since there are no existing MDOT ballast specification for high speed rail, it is assumed that aggregate ballast specifications for the Wolverine Line will use the higher international specifications. The Wolverine line, however, is located in southern Michigan is a region of sedimentary rocks which generally do not meet the existing MDOT ballast specifications. The investigation found that there were only 12 quarries in the Michigan that meet the MDOT specification. Of these 12 quarries, six were igneous or metamorphic rock quarries, while six were carbonate quarries. Of the six carbonate quarries four were locate in the Lower Peninsula and two in the Upper Peninsula. Two of the carbonate quarries were located in near proximity to the Wolverine Line, while the remaining quarries were at a significant haulage distance. In either case, the cost of haulage becomes an important consideration. In this regard, four of the quarries were located with lake terminals allowing water transportation to down state ports. The Upper Peninsula also has a significant amount of metal based mining in both igneous and metamorphic rock that generate significant amount of waste rock that could be used as a ballast material. The main drawback, however, is the distance to the Wolverine rail line. One potential source is the Cliffs Natural Resources that operates two large surface mines in the Marquette area with rail and water transportation to both Lake Superior and Lake Michigan. Both mines mine rock with a very high compressive strength far in excess of most ballast materials used in the United States and would make an excellent ballast materials. Discussions with Cliffs, however, indicated that due to environmental concerns that they would most likely not be interested in producing a ballast material. In the United States carbonate aggregates, while used for ballast, many times don't meet the ballast specifications in addition to the problem of particle degradation that can lead to fouling and cementation issues. Thus, many carbonate aggregate quarries in close proximity to railroads are not used. Since Michigan has a significant amount of carbonate quarries, the research also investigated using the dynamic properties of aggregate as a possible additional test for aggregate ballast quality. The dynamic strength of a material can be assessed using a split Hopkinson Pressure Bar (SHPB). The SHPB has been traditionally used to assess the dynamic properties of metal but over the past 20 years it is now being used to assess the dynamic properties of brittle materials such as ceramics and rock. In addition, the wear properties of metals have been related to their dynamic properties. Wear or breakdown of railroad ballast materials is one of the main problems with ballast material due to the dynamic loading generated by trains and which will be significantly higher for high speed rails. Previous research has indicated that the Port Inland quarry along Lake Michigan in the Southern Upper Peninsula has significant dynamic properties that might make it potentially useable as an aggregate for high speed rail. The dynamic strength testing conducted in this research indicate that the Port Inland limestone in fact has a dynamic strength close to igneous rocks and much higher than other carbonate rocks in the Great Lakes region. It is recommended that further research be conducted to investigate the Port Inland limestone as a high speed ballast material.

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The overall objective of this work was to compare the effect of pre-treatment and catalysts on the quality of liquid products from fast pyrolysis of biomass. This study investigated the upgrading of bio-oil in terms of its quality as a bio-fuel and/or source of chemicals. Bio-oil used directly as a biofuel for heat or power needs to be improved particularly in terms of temperature sensitivity, oxygen content, chemical instability, solid content, and heating values. Chemicals produced from bio-oil need to be able to meet product specifications for market acceptability. There were two main objectives in this research. The first was to examine the influence of pre-treatment of biomass on the fast pyrolysis process and liquid quality. The relationship between the method of pre-treatment of biomass feedstock to fast pyrolysis oil quality was studied. The thermal decomposition behaviour of untreated and pretreated feedstocks was studied by using a TGA (thermogravimetric analysis) and a Py-GC/MS (pyroprobe-gas chromatography/mass spectrometry). Laboratory scale reactors (100g/h, 300g/h, 1kg/h) were used to process untreated and pretreated feedstocks by fast pyrolysis. The second objective was to study the influence of numerous catalysts on fast pyrolysis liquids from wheat straw. The first step applied analytical pyrolysis (Py-GC/MS) to determine which catalysts had an effect on fast pyrolysis liquid, in order to select catalysts for further laboratory fast pyrolysis. The effect of activation, temperature, and biomass pre-treatment on catalysts were also investigated. Laboratory experiments were also conducted using the existing 300g/h fluidised bed reactor system with a secondary catalytic fixed bed reactor. The screening of catalysts showed that CoMo was a highly active catalyst, which particularly reduced the higher molecular weight products of fast pyrolysis. From these screening tests, CoMo catalyst was selected for larger scale laboratory experiments. With reference to the effect of pre-treatment work on fast pyrolysis process, a significant effect occurred on the thermal decomposition of biomass, as well as the pyrolysis products composition, and the proportion of key components in bio-oil. Torrefaction proved to have a mild influence on pyrolysis products, when compared to aquathermolysis and steam pre-treatment.

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Fast pyrolysis liquid or bio-oil has been used in engines with limited success. It requires a pilot fuel and/or an additive for successful combustion and there are problems with materials and liquid properties. It is immiscible with all conventional hydrocarbon fuels. Biodiesel, a product of esterification of vegetable oil with an alcohol, is widely used as a renewable liquid fuel as an additive to diesel at up to 20%. There are however limits to its use in conventional engines due to poor low temperature performance and variability in quality from a variety of vegetable oil qualities and variety of esterification processes. Within the European Project Bioliquids-CHP - a joint project between the European Commission and Russia - a study was undertaken to develop small scale CHP units based on engines and microturbines fuelled with bioliquids from fast pyrolysis and methyl esters of vegetable oil. Blends of bio-oil and biodiesel were evaluated and tested to overcome some of the disadvantages of using either fuel by itself. An alcohol was used as the co-solvent in the form of ethanol, 1-butanol or 2-propanol. Visual inspection of the blend homogeneity after 48 h was used as an indicator of the product stability and the results were plotted in a three phase chart for each alcohol used. An accelerated stability test was performed on selected samples in order to predict its long term stability. We concluded that the type and quantity of alcohol is critical for the blend formation and stability. Using 1-butanol gave the widest selection of stable blends, followed by blends with 2-propanol and finally ethanol, thus 1-butanol blends accepted the largest proportion of bio-oil in the mixture. © 2013 Elsevier Ltd. All rights reserved.

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A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. This considers all aspects of the special characteristics of bio-oil – how they are created and the solutions available to help meet requirements for utilisation. Particular attention is paid to chemical and catalytic upgrading including synthesis gas and hydrogen production which has seen a wide range of new research activities and also more limited attention to chemicals recovery. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material.

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A hot filtration unit downstream of a 1kg/h fluidised bed fast pyrolysis reactor was designed and built. The filter unit operates at 450oC and consists of 1 exchangeable filter candle with reverse pulse cleaning system. Hot filtration experiments up to 7 hours were performed with beech wood as feedstock. It was possible to produce fast pyrolysis oils with a solid content below 0.01 wt%. The additional residence time of the pyrolysis vapours and secondary vapour cracking on the filter cake caused an increase of non-condensable gases at the expense of organic liquid yield. The oils produced with hot filtration showed superior quality properties regarding viscosity than standard pyrolysis oils. The oils were analysed by rotational viscosimetry and gel permeation chromatography before and after accelerated aging. During filtration the separated particulates accumulate on the candle surface and build up the filter cake. The filter cake leads to an increase in pressure drop between the raw gas and the clean gas side of the filter candle. At a certain pressure drop the filter cake has to be removed by reverse pulse cleaning to regenerate the pressure drop. The experiments showed that successful pressure drop recovery was possible during the initial filtration cycles, thereafter further cycles showed minor pressure drop recovery and therefore a steady increase in differential pressure. Filtration with pre-coating the candle to form an additional layer between the filter candle and cake resulted in total removal of the dust cake.

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A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe, and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material. © 2012 American Institute of Chemical Engineers (AIChE).

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Dissolving-grade pulps are commonly used for the production of cellulose derivatives and regenerated cellulose. High cellulose content, low content of non-cellulosic material, high brightness, a uniform molecular weight distribution and high cellulose reactivity are the key features that determine the quality of a dissolving pulp. The first part of this work was an optimization study regarding the application of selected enzymes in different stages of a new purification process recently developed in Novozymes for purifying an eucalypt Kraft pulp into dissolving pulp, as an alternative to the pre-hydrolysis kraft (PHK) process. In addition, a viscosity reduction was achieved by cellulase (endoglucanase) treatment in the beginning of the sequence, while the GH11 and GH10 xylanases contributed to boost the brightness of the final pulp. The second part of the work aimed at exploring different auxiliary enzyme activities together with a key xylanase towards further removal of recalcitrant hemicelluloses from a partially bleached Eucalypt Kraft pulp. The resistant fraction (ca. 6% xylan in pulp) was not hydrolysable by the different combinations of enzymes tested. Production of a dissolving pulp was successful when using a cold caustic extraction (CCE) stage in the end of the sequence O-X-DHCE-X-HCE-D-CCE. The application of enzymes improved process efficiency. The main requirements for the production of a dissolving pulp (suitable for viscose making) were fulfilled: 2,7% residual xylan, 92,4% of brightness, a viscosity within the values of a commercial dissolving pulp and increased reactivity.