Biogas production from organic materials can be used as a renewable vehicle fuel, provide heat and generate electricity and can thereby reduce the greenhouse gas emissions. This thesis focuses on the biogas production based on lignocelluloses. There is an abundant availability of lignocelluloses, constituting 50% of the total biomass worldwide. However, the biomass recalcitrance limits the microbial degradation as well as the biogas production from these types of materials. In the present work different pretreatment methods have been performed in order to decrease the biomass recalcitrance and improve the biogas production. Steam explosion pretreatment, together with the addition of sodium hydroxide and hydrogen peroxide, has been performed on lignocellulosic-rich paper tube residuals. The pretreatment has resulted in methane yields of up to 493 NmL/gVS, which is an increase by 107% compared with untreated material. Furthermore, the use of an organic solvent, N-methylmorpholine-N-oxide (NMMO), was evaluated as a pretreatment method for spruce (both chips and milled), rice straw, and triticale straw. The NMMO pretreatment resulted in 202, 395, 328, and 362 NmL CH4/g carbohydrates produced of these substrates, respectively, corresponding to an increase of between 400-1,200% compared with the untreated version of the same material. Moreover, the paper tube residuals have been co-digested with an unstable nitrogen-rich substrate mixture, mainly based on municipal solid waste. The addition of the lignocellulosic-rich paper tubes in a co-digestion process showed stabilizing effects and prevented the accumulation of volatile fatty acids with a subsequent reactor failure. Additionally, synergistic effects have been found leading to between 15-33% higher methane yields when paper tubes were added to the co-digestion process compared with the yields calculated from the methane potentials of the two substrates. Substrate characterization analysis can be used to study the changes on the lignocellulosic components after the pretreatment, relating the changes to the performance in the anaerobic digestion. Increased accessible surface area, measured by the Simons’ stain and the enzymatic adsorption methods, as well as decreased crystallinity, determined by using the Fourier Transform Infrared Spectroscopy, can all be linked to improved biogas production after pretreatment. Finally, the NMMO pretreatment on forest residues has been financially evaluated for an industrial scale process design. The base case that was evaluated simulated a case where pretreated forest residues were co-digested with the organic fraction of municipal solid waste to obtain optimal nutritional balance for the anaerobic digestion. This process has been found to be economically feasible with an internal rate of return of 20.7%. / <p>Akademisk avhandling som för avläggande av teknologie doktorsexamen vid Chalmers tekniska högskola försvaras vid offentlig disputation den 24 maj 2013, klockan 10.00 i KA,Kemigården 4, Göteborg</p>

Background: Transferring cost-effectiveness information between geographic domains offers the potential for more efficient use of analytical resources. However, it is difficult for decision-makers to know when they can rely on costeffectiveness evidence produced for another context. Objectives: This thesis explores the transferability of economic evaluation results produced for one geographic area to another location of interest, and develops an approach to identify factors to predict when this is appropriate. Methods: Multilevel statistical models were developed for the integration of published international costeffectiveness data to assess the impact of contextual effects on country-level; whilst controlling for baseline characteristics within, and across, a set of economic evaluation studies. Explanatory variables were derived from a list of factors suggested in the literature as possible constraints on the transferability of costeffectiveness evidence. The approach was illustrated using published estimates of the cost-effectiveness of statins for the primary and secondary prevention of cardiovascular disease from 67 studies and related to 23 geographic domains, together with covariates on data, study and country-level. Results: The proportion of variation at the country-level observed depends on the appropriate multilevel model structure and never exceeds 15% for incremental effects and 21% for incremental cost. Key sources of variability are patient and disease characteristics, intervention cost and a number of methodological characteristics defined on the data-level. There were fewer significant covariates on the study and country-levels. Conclusions: Analysis suggests that variability in cost-effectiveness data is primarily due to differences between studies, not countries. Further, comparing different models suggests that data from multinational studies severely underestimates country-level variability. Additional research is needed to test the robustness of these conclusions on other sets of cost-effectiveness data, to further explore the appropriate set of covariates, and to foster the development of multilevel statistical modelling for economic evaluation data in health.

This project investigates how remanufacturing of robotic lawn mowers can be incorporated into an existent forward supply chain. The project is conducted as a single case study on Husqvarna where an interview study and a literature study provide the empirical data and theory, respectively. Alternatives are proposed for potential remanufacturing cases at various locations, where different parties ranging from original equipment manufacturers to independent manufacturers perform the remanufacturing process. SWOT analyses are conducted to identify the most promising alternatives for a further economic analysis. The economic evaluation is based on net present values and a sensitivity analysis which together determines the feasibility of the alternatives. The results of the project answer three research questions. The first concludes that out of seven defined production systems there are only two that are not suitable for remanufacturing in a general case mainly due to the low flexibility of these systems. The results of the second identifies labor, logistics, and operational prerequisite factors that must be considered when implementing remanufacturing for case specific alternatives. The conclusion of the third research question lists the feasibility of the alternatives from which the recommendations for Husqvarna are presented. This project recommends Husqvarna to implement a remanufacturing process for their robotic lawn mowers either by enlisting their current dealers or by themselves at a location nearby the spare parts warehouse in Torsvik. Which alternative is the most profitable depends mainly on the expected quantity of the acquired cores, i.e. Husqvarna as a centralized remanufacturer benefits more from higher quantities while the decentralized dealer alternative would comparably be more profitable if the quantities were lower. As it is perceived that initial collected quantities will be low, and possibly even somewhat higher for the dealers, a decentralized remanufacturing process could be the most profitable alternative to start with. Using a third-party remanufacturer is also feasible but considered risky and therefore not recommended as they could have the same core acquisition problem as Husqvarna while having lower profitability.

O lodo gerado em processos de galvanoplastia é classificado pela ABNT NBR 10.004/04 como perigoso (classe I). Na literatura encontram-se poucos estudos referentes à recuperação do cromo presente no lodo gerado em sistemas de tratamento de efluentes de indústrias de galvanoplastia. Neste sentido, o presente estudo avaliou a remoção do cromo presente no lodo de galvanoplastia por meio de dois processos, visando avaliar à eficiência técnica e a viabilidade econômica de ambos. O Processo 1 consistiu na remoção do cálcio utilizando o ácido cítrico, seguida de lixiviação ácida. Na etapa de oxidação, variou-se a temperatura em 40ºC, 60ºC e 80ºC e no tempo de 30, 60 e 90 minutos, tendo em vista que a eficiência do processo de oxidação depende da temperatura e tempo. Nesta etapa do processo as concentrações de peroxido de hidrogênio (H2O2) utilizadas foram de 1,50, 3,00 e 4,50 mol.L-1. O Processo 2 realizou a oxidação do cromo sem efetuar as etapas de extração do cálcio e a lixiviação ácida. A oxidação do cromo ocorreu pelo mesmo método apresentado no Processo 1. A caracterização elementar da amostra determinou que o principal elemento constituinte do lodo é o cálcio (20,05% em massa), e que dentre os metais pesados destacam-se o cromo e o níquel (6,52% e 4,33% em massa, respectivamente). A maior eficiência de remoção do cálcio foi obtida na razão mássica de 8,00 (ácido cítrico/hidróxido de cálcio), com 51,76% em massa, seguida pela razão mássica de 5,50 com 36,75% em massa e 2,50 com 24,83% em massa. O melhor resultado de oxidação do cromo no Processo 1 foi obtido com tempo de 30 minutos, temperatura de 60ºC e concentração de peroxido de hidrogênio de 3,00 mol.L-1, com eficiência de 41,09% em massa. No Processo 2, obteve-se a remoção de 37,96% em massa de cromo a temperatura de 80ºC, por uma hora e 3,00 mol.L-1 de peróxido de hidrogênio. Avaliando os custos para remoção do cromo dos dois processos, determinou-se que o Processo 1 foi mais oneroso que o 2, porém ambos não apresentaram viabilidade econômica para aplicação em escala industrial. Nos dois processos efetuou-se a oxidação do cromo presente no lodo de galvanoplastia, permitindo a sua remoção parcial neste resíduo. Com isso obtiveram-se ganhos ambientais, pela diminuição deste elemento no resíduo de galvanoplastia, que na maioria das vezes é disposto em aterros classe I, gerando um passivo ambiental. / The sludge generated in electroplating processes is classified by NBR 10.004/04 as a hazardous material (class I). In the literature, few studies report the recovery of chromium present in the electroplating sludge generated in the industries. In this sense, the present study conducted the removal of chromium in the electroplating sludge through two different processes, aiming to evaluate their efficiency and economic viability. The first process removed calcium through the use of citric acid being performed by varying the ratio of citric acid/calcium hydroxide (2.5, 5.5 and 8.0). Then, were performed the leaching of the samples. According to the literature, the efficiency of the oxidation process varies depending on the reaction temperature, time and concentration of hydrogen peroxide. For this reason, samples were heated to a temperature ranging from 40°C, 60°C and 80°C. Also, were conducted variations in the concentrations of hydrogen peroxide (1.5, 3.0 and 4.5 mol.L-1) and reaction time (30, 60 and 90 minutes). The second Process consisted in the chrome recovery by using the galvanic sludge without removal of the calcium and acid leaching. The chrome oxidation occurred by the same method shown in Process 1. Elemental characterization of the samples determined that the primary sludge constituent was calcium (20.05% by weight), and in terms of heavy metals, the chromium and the nickel (6.52% and 4.33% by mass, respectively). Most of calcium removal efficiency was obtained at a rate of 8 with 51.76% by mass, then the ratio of 5.50 to 36.75% by mass and 2.50 to 24.83% by mass. The best oxidation result of chromium in Process 1 was obtained using a time of 30 minutes, 60°C and hydrogen peroxide concentration of 3 mol.l-1, with 41.09 wt% efficiency. In Process 2 was obtained the removal of 37.96% by mass of chromium temperature of 80°C, for one hour and 3,00 mol.l-1 of hydrogen peroxide. Evaluating the costs for chrome removal of the two processes was determined that the Process 1 was more costly than 2, but both showed no economic feasibility for implementation on an industrial scale. However, in both cases occurred the oxidation of chromium present in the electroplating sludge, allowing its removal from the residue. Thus, environmental gains have been achieved by the reduction of this element in electroplating waste, which mostly is intended for landfill class I, generating an environmental liability.

As técnicas utilizadas pelas empresas atualmente para a avaliação econômica dos projetos de investimento em condições de risco, com destaque para a análise de cenários, apresentam três importantes limitações: não fornecem o capital no risco, utilizam uma taxa mínima da atratividade (TMA) única para a empresa em seu todo, desprezando as particularidades de cada caso, e tratam o risco isoladamente, fora do contexto amplo da diversificação eficiente. Diante desse contexto, o presente estudo propôs a aplicação de três modelos originários do mercado de capitais: o valor no risco (VAR), o modelo de precificação dos ativos de capital (CAPM) e a teoria de precificação por arbitragem (APT). Os resultados obtidos mostram que tais modelos são capazes de: fornecer o capital no risco dos projetos de investimento (VAR), utilizar uma TMA própria, segundo as particularidades de cada projeto de investimento (CAPM e APT), e tratar o risco em projetos de investimento no contexto amplo da diversificação eficiente (VAR, CAPM e APT). / The techniques used now by the companies for the economic evaluation of the investment projects in risk conditions, with prominence for the analysis of sceneries, present three important limitations: they don\'t supply the capital in the risk, they use an attractiveness of minimum rate (TMA) only for the company in its whole, despising the particularities of each case, and they treat the risk separately, out of the wide context of the efficient diversification. Before of that context, the present study proposed the application of three original models of the market of capitais: the value at risk (VAR), the capital asset pricing model (CAPM) and the arbitrage pricing theory (APT). The obtained results showed that such models are capable of: to supply the capital in the risk of the investment projects (VAR), to use an own TMA, according to the particularities of each investment project (CAPM and APT), and to treat the risk in investment projects in the wide context of the efficient diversification (VAR, CAPM and APT).

Cette thèse s’inscrit dans le débat scientifique actuel autour de l’évaluation économique des services écosystémiques fournis par les aires marines protégées (AMP) dans les pays en voie de développement. Appliquant la méthode de l’évaluation contingente, elle s’est intéressée à l’analyse de la perception de la population mauritanienne des services écosystémiques fournis par l’aire marine protégée du parc national du banc d’arguin (PNBA) en Mauritanie et la valeur qu’elle consente à payer pour maintenir l’offre de ces services dans son état actuel. A travers l’analyse des résultats de trois enquêtes réalisées au PNBA (niveau local), à Nouakchott (zone adjacente) et à Tidjikja (arrière-pays), la thèse discute l’impact de la distance, dans le sens de l’éloignement et du temps nécessaire pour accéder à l’AMP, tant sur la perception des services écosystémiques fournis par le PNBA que sur le consentement à payer pour sa conservation. Par ailleurs, elle aborde l’applicabilité de la méthode de l’évaluation contingente dans les pays en voie de développement et propose quelques améliorations du protocole de l’enquête pour améliorer la fiabilité des résultats. / This thesis is part of the current scientific debate around the economic evaluation of ecosystem services provided by marine protected areas in developing countries. Using the contingent valuation method, it focused on the analysis of the Mauritanian population's perception of ecosystem services provided by the marine protected area of Banc d'Arguin National Park in Mauritania and the value that this population agrees to pay to maintain the supply of these services in its current state. Through the analysis of the results of three surveys conducted at the PNBA (local level), Nouakchott (adjacent zone) and Tidjikja (inland), the thesis discusses the impact of distance, in the sense of the remoteness and the time required to access the MPA, both on the perception of the ecosystem services provided by the PNBA and on the Willingness To Pay for its conservation.In addition, it discusses the applicability of the contingent valuation method in developing countries and proposes some improvements to the survey protocol to enhance the reliability of the results.

Orientador: Miguel Luiz Menezes Freitas / Resumo: Araucaria angustifolia (Bertol.) O. Kuntze ou pinheiro-do-paraná é uma espécie florestal fornecedora de madeira valiosa e sementes de alto valor nutritivo, mas considerada em risco de extinção. A manutenção de plantios com a finalidade de conservação da espécie é uma estratégia complementar para reduzir a possibilidade de erosão genética em seu habitat natural. Assim, este trabalho teve por objetivo avaliar a viabilidade técnica e econômica da conservação genética da Araucaria angustifolia a partir de um teste de procedências e progênies, que será transformado em uma área de produção de sementes, com a finalidade de manter uma representação da base genética da espécie e fornecer material genético de qualidade para fins de produção de madeira e sementes. Estabeleceu-se o experimento em abril de 1982, na Estação Experimental de Itapeva, do Instituto Florestal, no Estado de São Paulo. O delineamento experimental adotado foi em blocos de famílias compactas com três repetições, cinco procedências (parcelas), 14 a 26 progênies/procedência (subparcelas), 10 plantas por subparcela e espaçamento de 3,0 x 2,0 metros. Avaliou-se o experimento aos 33 anos de idade tendo sido considerado os seguintes caracteres: sobrevivência (%), altura total (m), diâmetro à altura do peito (DAP, cm) e volume (m³). A análise genético-estatística do experimento com o auxílio do software Selegen estimou os parâmetros genéticos, conforme a metodologia do modelo linear misto univariado aditivo REML/BLUP (Res... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Araucaria angustifolia (Bertol.) O. Kuntze is a kind forest species supplier wooden valuable and seeds of recognized nutritional value, however considered threatened on extinction. Plantations maintenance with species conservation purpose is a complementary strategy to reduce genetic erosion in natural areas. So, the aim of this work was to evaluate technical and economic viability of Araucaria angustifolia genetic conservation by the use. The analyzed provenance and progeny test was established in 1982 at Itapeva Experimental Station – São Paulo State, from Forestry Institute, following a compact family blocks design with 110 open-pollinated progenies, from five natural populations, three replicates, ten plants per subplot, spaced from 3,0 x 2,0 meters. At age 33 the trial was measured for following traits: total height, diameter at breast height (DBH), wood volume and survival. The variance components and genetic parameters estimates were performed by REML/BLUP methods (Restricted maximum likelihood/Best linear unbiased prediction) using Selegen software. The production and management scenarios were obtained by using SisAraucaria software. Sensitivity analysis and economic parameters estimates were obtained through several methods of economic evaluation using the Planin software. In general, genetic parameters indicated that the evaluated population has enough variability for both conservation and breeding, and it suggests a technical viability use in seedling seed orchard.... (Complete abstract click electronic access below) / Doutor

O presente trabalho contextualiza a importância da determinação da viabilidade técnico-financeira em sistemas de produção de bovinos de corte, através da aplicação de uma análise técnica e econômica. O objetivo do presente estudo foi realizar uma análise produtiva e econômica de sistemas de produção de bovinos de corte na região do Pampa do Rio Grande do Sul. Foram analisadas quatro propriedades rurais pertencentes a uma empresa agropecuária, localizadas no município de Dom Pedrito, e denominadas como Sistema de Cria em Campo Nativo (SCN), Sistema de Cria com Agricultura (SCA), Sistema de Recria-Terminação (SRT) e o Sistema de Terminação (ST). Para avaliar o efeito da escala de produção sobre a eficiência da atividade, foi simulado um quinto sistema, denominado SIA (Sistema de Integração de Atividades), integrando todas as propriedades da empresa, por meio do somatório dos parâmetros físicos e econômicos dos quatro sistemas independentes. Posteriormente, foram gerados índices técnicos e financeiros para realizar a análise do SIA. A maior produtividade foi alcançada pela unidade SRT, seguida da unidade ST, com 296 e 98 kg.ha-1, respectivamente. Os sistemas SIA, SCN e SCA foram os menos produtivos dos cinco avaliados, com 88, 86 e 83 kg.ha-1, respectivamente. Entretanto, o SCN foi mais eficiente em termos econômicos que os demais sistemas. O custo de oportunidade e a mão de obra foram os itens que mais oneraram os sistemas de SCN, SCA e SIA, com 38,8 e 23,6%, 42,9 e 27,3% e 40,7 e 26,6%, respectivamente, enquanto que nos SRT e ST foi a aquisição de animais com 61,7 e 71,5%, respectivamente. Os resultados positivos de margem líquida dos sistemas SCN (0,96 R$.kg-1) e SRT (0,93 R$.kg-1) foram responsáveis pela viabilidade econômica do sistema simulado, que apresentou margem líquida de 0,04 R$.kg-1. O efeito na escala de produção demonstrou ser positivo entre os sistemas, pois houve diluição nos custos fixos de produção no sistema simulado. / This study contextualizes the importance of determining the technical and financial viability of beef cattle production systems through the application of technical and economic analysis. The aim of study was to evaluate the productive and economic analysis of a beef cattle production in the Pampa region of Rio Grande do Sul, Brazil. Data were collected from four properties from the same farming company, located in Dom Pedrito, RS. Production systems were defined as Cow-Calf System in Nature Pasture (CCNP), Cow- Calf in System and Agriculture (CCA), Rearing-Fattening System (RFS) and Fattening System (FS). We also simulated an additional system to evaluate the effect of production scale in the activity efficiency defined as Integration Activities System (IAS) that integrates all company farms. The IAS comprises the physical and economic parameters from four independent properties. The RFS farm had the highest productivity, with 296 kg.ha-1, followed by FS, IAS, CCNP and CCA. The RFS farm had the highest productivity, with 296 kg.ha-1, followed by FS, IAS, CCNP and CSA, with 98, 88, 86 e 83 kg.ha-1, respectively. The RFS showed highest productive and the CCNP demonstrated the highest economic results. The costs of opportunity and labour were higher for CCNP, CSA and IAS compared to RFS and FS, which have the animal’s acquisition as their main costs of production. The positives economic results of CCNP (0.96 R$.kg) and RFS (0.93 R$.kg-1) farms showed where responsible to economic viability of simulated system, that presented positive net margin (0.04 R$.kg-1). The effect on production scale was positive between systems by the attenuated on production fixed costs in the simulated system.

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-06Bitstream added on 2014-06-13T18:48:58Z : No. of bitstreams: 1 novaes_af_me_jabo.pdf: 1108978 bytes, checksum: 6edc74fb32aa05ccc7e72ae5d3614ab1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Nos últimos anos, a demanda pelo pescado tem aumentado significativamente. Atualmente, a pesca, que contribui com a maior parte deste produto, vem apresentando estagnação, ou ligeira queda na oferta em alguns anos como foi o caso de 2006. Em contrapartida, a aquicultura moderna, que passa por grandes avanços científicos e tecnológicos, vem suprindo esta deficiência no mercado. O Brasil, detentor de 12% de toda água doce mundial, deverá se tornar brevemente um grande produtor no cenário mundial. Um dos grandes diferenciais do país, além de possuir clima favorável, é a disponibilidade de grandes reservatórios, que tem sido aproveitado para o cultivo de peixes em tanques-rede. O presente estudo, desenvolvido em piscicultura comercial, no Reservatório de Furnas, curso médio do rio Grande, município de São José da Barra MG teve como objetivo comparar os principais indicadores zootécnicos e econômicos da tilapicultura em sistema super-intensivo (tanques-rede) em duas diferentes dimensões 6 e 18 m3. Foram utilizados 12.960 juvenis machos revertidos da tilápia-do-nilo (Oreochromis niloticus). Durante todo o período experimental, os peixes receberam ração extrusada especial para tilápias em cultivos super-intensivo e a oferta variou de acordo com a biomassa e temperatura da água, iniciando com 8% e decrescendo até 1%. Foram avaliados os seguintes índices zootécnicos: sobrevivência (%), peso médio (g), biomassa (kg), ganho de biomassa (kg), ganho em peso diário (g), conversão alimentar aparente e densidade (kg/m3). A análise econômica foi elaborada a partir da determinação do custo total de produção e do lucro de cada tratamento. Os dados deste estudo permitem concluir que, embora não diferindo nos principais indicadores zootécnicos, a produção de tilápias em tanques-rede de maior dimensão proporcionou menor custo total médio e maior rentabilidade / In the past few years, demand for fish has increased significantly. At present, fishing, which contributes with the largest part of this product, has shown stagnation or slight falling in the offer in some years, as in the case of 2006. On the other hand, modern aquiculture, with technological and scientific improvement, has been supplying this deficit on the market. Brazil, with 12% of the world's fresh water, will probably become one of the greatest consumers soon. Besides the favorable weather, there is also the availability of large reservoirs, which has been used for the growing of fish in net cage. The present study, developed at Furnas reservoir, medium course of Grande river, in São José da Barra/MG, had as its aim compare the economic and zootechnic indicators of tilapiculture in super intensive system net cages in two different dimensions 6 and 18 m3. 12,960 reversed male juvenils from Nile tilapia were used (Oreochromis niloticus). During the experiment the fish received (extrusada) special ration for tilapia in super intensive culture and the offer varied according to the biomass and water temperature, beginning with 8% and decreasing until 1%. The following zootechnic indexes were evaluated: survival (%), average weight (g), biomass (kg), gain of biomass (kg), gain of daily weight (g), apparent nutritional conversion and density (kg/m3). The economic analysis was made after the determination of the total cost of the production and the profit of each treatment. The data in this study allows the conclusion that the production of tilapia in (net cages) of bigger dimension offered bigger rentability

With theoretical foundations in welfare theory, the cost benefit analysis (CBA) technique is a powerful tool for assessing benefits particularly where markets do not exist or would fail (for example due to the existence of public goods) or have become potentially politically excluded (such as the health sector). Unlike other economic evaluation techniques, costs and benefits are measured in monetary terms allowing for comparisons within and between different sectors of the economy for resource allocation decisions. Using contingent valuation (CV) techniques, people's preferences for goods are determined by finding out what they would be willing to pay (WTP) for specified benefits or improvements; or accept (WTA), as compensation for withdrawal or loss of benefit. While the use of WTP methods has grown in other sectors, the uptake in health has been limited. A long-standing criticism is that stated WTP estimates may be poor indicators of actual WTP, calling into question their validity and the use of such estimates for welfare valuation. The aim of this thesis is to investigate the criterion validity of CV-WTP studies. A four-pronged approach including critical appraisals of the available literature and evidence on criterion validity and empirical analyses was adopted. The thesis established the scarcity in criterion validity assessments, particularly in the health sector and that evidence on the criterion validity of CV-WTP is more varied than authors are presenting. The variety in the methods used to assess and report criterion validity assessments is demonstrated. Further, the impact of the analysis of hypothetical WTP on criterion validity assessments and conclusions thereof is demonstrated. The empirical analyses further demonstrate the differences in predictions and predictors of WTP analyses, discussing the effect of these on criterion validity assessments and conclusions. Finally, the thesis offers suggestions for the reporting of criterion validity assessments, in efforts to improve the method.