The aim of this study is to carry out a fairly overall empirical analysis of the conditions of production in an industry. The aim of the empirical analysis is, however, not only to give information about empirical conditions, such as technical development, efficiency of production, etc, but also to illustrate the theoretical and methodological problems in the economic theory of production.The engineering analysis makes the foundation from which economic production functions are constructed. As the study focuses on Leif Johansen!s production model, four different types of functions are constructed: ex ante and ex post micro functions and long run and short run macro functions. A study of structural changes and technical development in the periods 1960-1975 and 1850-1975 then follows. For the first period a study of productive efficiency is also made.A discussion of theoretical problems is integrated with the empirical analysis, Two big problems in production theory are, however, dealt with separately, namely the theory of engineering production analysis and the aggregation of micro production functions.It is difficult to state a specitic conclusion with just a few words. The study consists of so many minor observations and results, that it is difficult to lift out any separate. A negative general conclusion can perhaps be said to be that great scepticism should be shown the empirical value of ordinary production function estimates. On the other hand, the positive conclusion can be said to be the fact that the dissertation shows the value of having an engineering approach in empirical studies of production. / digitalisering@umu

Markets have an important role to play in advancing an improved understanding of international trading relationships. Two most important economic issues, which contribute to improved national welfare and ensure long-run competitive market equilibrium in international markets, are market integration and market efficiency. To provide softwood lumber markets related information to the policy makers, economic analyses relating market integration and market efficiency of the combined markets of Canada and the US have been conducted. The economic analyses include: (i) testing cointegration of prices among North American softwood lumber markets; (ii) identifying price leading markets in long-run price structure of these cointegrated markets; (iii) examining the degree of market integration among these markets; and (iv) testing the efficiency of spatial arbitrage among these markets. First, the price linkages in the North American softwood lumber markets have been explored over different trade regimes. The results indicate that market integration is affected by product aggregation of data. Further investigations of market integration are, therefore, limited to homogeneous softwood lumber product markets. Second, oligopsonistic pricing behavior of traders is identified as the possible reason for imperfect competition among Douglas Fir product markets, while imperfect competition among the markets of Spruce-Pine-Fir and Hem Fir products can not be explained by this behavior. Third, a comprehensive picture of the adherence to price parity is formulated by evaluating the magnitude and persistence of deviations from equilibrium relation of prices. It is found that large volumes of trade, product substitutability, lower prices, and certainty of trade are the factors which contribute to higher degree of market integration among North American softwood lumber product markets. Finally, the inter-temporal shifts in regime probabilities of competitive market equilibrium are assessed over different trade regimes. It is found that lower transaction costs, large volumes of trade, short distances between markets, and certainty of trade contribute to high market efficiency among softwood lumber product markets of North America.

In this study, a numerical model is developed for determining coupled heat and moisture transfer in a run-around membrane energy exchanger (RAMEE) using two counter/cross flow exchangers and with a salt solution of MgCl2 as the coupling fluid. The counter/cross flow exchanger is a counter-flow exchanger with cross-flow inlet and outlet headers. The model is two-dimensional, steady-state and based on the physical principles of conservation of momentum, energy, and mass. The finite difference method is used in this model to discretize the governing equations.<p> The heat transfer model is validated with effectiveness correlations in the literature. It is shown that the difference between the numerical model and correlations is less than ¡À2% and ¡À2.5% for heat exchangers and run around heat exchangers (RAHE), respectively. The simultaneous heat and moisture transfer model is validated with data from another model and experiments. The inter-model comparison shows a difference of less than 1%. The experimental validation shows an average discrepancy of 1% to 17% between the experimental and numerical data for overall total effectiveness. At lower NTUs the numerical and experimental results show better agreement (e.g. within 1-4% at NTU=4).<p> The model for RAHE is used to develop new effectiveness correlations for the geometrically more complex counter/cross flow heat exchangers and RAHE systems. The correlations are developed to predict the response of the exchangers and overall system to the change of different design characteristics as it is determined by the model. Discrepancies between the simulated and correlated results are within ¡À2% for both the heat exchangers and the RAHE systems.<p> It is revealed by the model that the overall effectiveness of the counter/cross flow RAMEE depends on the entrance ratio (the ratio of the length of the inlet and outlet headers to the length of the exchanger, xi/x0), aspect ratio (the ratio of the height to the length of the exchanger, y0/x0), number of heat transfer units (NTU), heat capacity rate ratio (Cr*), number of mass transfer units (NTUm), and the mass flow rate ratio of pure salt in desiccant solution to dry air (m*). Beside these dimensionless parameters, the performance of the RAMEE system is affected by the liquid-air flow configuration and the operating inlet temperature and humidity.<p> This study concludes that the maximum effectiveness of the RAMEE system with two counter/cross flow exchangers occurs when NTU and NTUm are large (e.g. greater than 10). At any NTU, the overall effectiveness of the RAMEE system increases with Cr* until it reaches a maximum value when Cr*= . Increasing Cr* above causes the overall effectiveness to decrease slightly. Therefore, to achieve the maximum overall effectiveness of the system, Cr* must be close to . is a function of NTU and operating conditions e.g., with NTU=10, and under AHRI summer and winter operating conditions, respectively. The exchangers in the RAMEE system are needed to have a small aspect ratio (e.g. y0/x0<0.2) and small entrance ratio (e.g. xi/x0<0.1) to get the maximum overall effectiveness of a RAMEE system using two counter/cross flow exchangers. Such a RAMEE system has a total effectiveness 6% higher and 1.5% lower compared to the same cross-flow and counter-flow RAMEE, respectively (at NTU=10, Cr*¡Ö3, y0/x0=0.2 and xi/x0=0.1).

In simulation, time averages are important for estimating equilibrium parameters. In particular, we would like to have the variance, bias and mean-square error for time averages. First, we will discuss various factors and their effect on the bias, the variance and the mean-square error. We will use the Markovian Event System to model various systems, including M/M/1 queues, M/E_k/1 queues, M/M/c queues, sequential queues, inventory systems and queueing networks. We use a numerical method for the computation of the variance, the bias and the mean-square error of the time average. The effectiveness of the method is tested by experimenting with models of various stochastic systems. The contribution of this thesis is to use numerical and graphical interpretations to study the general characteristics of the measures. The important characteristics included in our study are decomposability and periodicity.

Volunteer-managed nonprofit organizations (VNPOs) are defined as nonprofit organizations managed exclusively by volunteers without paid-staff. There is no well-recognized theory describing how to govern or structure VNPOs, despite their significance in the social economy. This study argues non-bureaucratic governance and non-hierarchical structures are appropriate for some VNPOs. Rothschild-Whitt (1979) proposes six significant challenges for organizations with non-bureaucratic governance. Using multiple case-study methodology, the magnitude of these challenges was assessed in three VNPOs adopting non-bureaucratic governance and non-hierarchical structure. Four challenges, namely, time, homogeneity, emotional intensity, and individual differences, did not adversely affect the selected VNPOs. Two challenges, namely, nondemocratic individuals and environmental constraints, remained obstacles for the selected VNPOs. Five other challenges to non-bureaucratic governance specific to VNPOs were also identified and discussed, specifically, succession planning and recruitment, task completion, minimal socialization, pressure to achieve consensus, and administrative issues. Insights from such studies may help to better manage non-bureaucratic/non-hierarchical VNPOs.

The goal of this study is to develop a robust theory that explains how participation in a Consumer-Run Organization (CRO) can lead to positive individual outcomes. To accomplish this goal, existing theoretical explanations are reviewed. Using the previously unapplied theoretical perspective of symbolic interactionism and more specifically, Stryker’s Identity Theory, these varying theoretical explanations are then integrated to create a model explaining how CROs can contribute to positive outcomes. This theoretical model is then empirically explored through two separate studies. The first uses open-ended short answer questions to understand how CRO members benefit from participation. The second uses participant observation and minimally structured interviews to generate life stories that explore how CRO participation has altered an individual’s life course. The original explanatory model proved helpful but partially inadequate in accounting for the results. This leads to model revisions and the development of a more robust theoretical explanation of how CRO lead to positive outcomes. Discussion focuses on explaining this revised explanatory model, exploring how it does and does not account for the results. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Psychology / "December 2005."

Volunteer-managed nonprofit organizations (VNPOs) are defined as nonprofit organizations managed exclusively by volunteers without paid-staff. There is no well-recognized theory describing how to govern or structure VNPOs, despite their significance in the social economy. This study argues non-bureaucratic governance and non-hierarchical structures are appropriate for some VNPOs. Rothschild-Whitt (1979) proposes six significant challenges for organizations with non-bureaucratic governance. Using multiple case-study methodology, the magnitude of these challenges was assessed in three VNPOs adopting non-bureaucratic governance and non-hierarchical structure. Four challenges, namely, time, homogeneity, emotional intensity, and individual differences, did not adversely affect the selected VNPOs. Two challenges, namely, nondemocratic individuals and environmental constraints, remained obstacles for the selected VNPOs. Five other challenges to non-bureaucratic governance specific to VNPOs were also identified and discussed, specifically, succession planning and recruitment, task completion, minimal socialization, pressure to achieve consensus, and administrative issues. Insights from such studies may help to better manage non-bureaucratic/non-hierarchical VNPOs.

In this study, a novel counter-cross-flow run-around membrane energy exchanger (RAMEE) system was designed and tested in the laboratory. The RAMEE system consists of two (2) counter-cross-flow Liquid-to-Air Membrane Energy Exchangers (LAMEEs) to be located in the supply and exhaust air streams in the building Heating Ventilation and Air-Conditioning (HVAC) system. Inside each exchanger, a micro-porous membrane separates the air and liquid streams and allows transfer of the sensible and latent energy from the air stream to the liquid stream or vice-versa. The system exchanges sensible and latent energy between supply and exhaust air streams using a desiccant solution loop. The supply and exhaust air streams in the RAMEE can be located far apart from each other or adjacent to each other. The flexibility of non-adjacent ducting makes the RAMEE system a better alternative compared to available energy recovery systems for the retrofit of HVAC systems.<p> Two counter-cross-flow exchangers for the RAMEE system were designed based on an industry recommended standard which is to obtain a target overall system effectiveness of 65% for the RAMEE system at a face velocity of 2 m/s. The exchanger design was based on heat exchanger theory and counter-cross-flow design approach. An exchanger membrane surface aspect ratio (ratio of exchanger membrane surface height to exchanger length) of 1/9 and the desiccant solution entrance ratio (ratio of desiccant solution entrance length to exchanger length) of 1/24 were employed. Based on different heat transfer case studies, the energy transfer size of each exchanger was determined as 1800 mm x 200 mm x 86 mm. ProporeTM was used as the membrane material and Magnesium-Chloride solution was employed as the desiccant solution.<p> The RAMEE performance (sensible, latent and total effectiveness) was evaluated by testing the system in a run-around membrane energy exchanger test apparatus by varying the air stream and liquid solution-flow rates at standard summer and winter operating conditions. From the test data, the RAMEE effectiveness values were found to be sensitive to the air and solution flow rates. Maximum total effectiveness of 45% (summer condition) and 50% (winter condition) were measured at a face velocity ¡Ö 2 m/s. A comparison between the experimental and numerical results from the literature showed an average absolute discrepancy of 3% to 8% for the overall total system effectiveness. At a low number of heat transfer units, i.e. NTU = 4, the numerical and experimental results show agreement within 3% and at NTU = 12 the experimental data were 8% lower than the simulations. The counter-cross-flow RAMEE total system effectiveness were found to be 10% to 20% higher than those reported for a cross-flow RAMEE system by another researcher.<p> It is thought that discrepancies between experimental and predicted results (design and numerical effectiveness) may be due to the mal-distributed desiccant solution-flow, desiccant solution leakage, lower than expected water vapor permeability of the membrane, uncertainties in membrane properties (thickness and water vapor permeability) and heat loss/gain effects. Future research is needed to determine the exact cause of the discrepancies.

This thesis contains the numerically investigations of the performance of a run-around membrane energy exchanger (RAMEE) at different outdoor air conditions and the effects of non-uniform exchanger channels. The RAMEE is a new type of building ventilation air energy recovery system that allows heat and moisture to be transferred between isolated supply and exhaust air streams. Two liquid-to-air membrane energy exchangers (LAMEEs) are placed in the supply and exhaust air ducts and transfer heat and moisture between air and a circulating liquid desiccant that couples the two LAMEEs together. The ability of the system to transfer heat and moisture between isolated supply and exhaust ducts makes it appropriate for numerous HVAC applications (e.g., hospitals and building energy retrofits). <p> The performance of the RAMEE at different outdoor air conditions is shown to be highly variable due to the coupling of the heat and moisture transfer by the desiccant. This coupling allows the humidity ratio between the indoor and outdoor air to influence the heat transfer and the moisture transfer is influenced by the difference between the indoor and outdoor air temperatures. The coupling produces some complex RAMEE performance characteristics at some outdoor air conditions where the effectiveness values (i.e., sensible, latent, and total) were shown to be less than 0% or greater than 100%. Effectiveness and operating correlations are developed to describe these complex behaviours because existing correlations do not account for the coupling effects. The correlations can serve as design and operation tools for the RAMEE which do not require the use of an iterative computational numerical model.<p> Non-uniform exchanger channels are present in the RAMEE because of pressure differences between the air and solution channels which deform the membrane into the air channel. The non-uniform channels are analytically shown to create maldistributed fluid flows and variable heat and mass transfer coefficients. The combined effects of these two changes lead to a reduction in the RAMEE effectiveness, which increases as the size of the membrane deformation increases. The reduction in total effectiveness for an exchanger where the membrane has a peak deflection of 10% of the nominal air channel thickness operating at a NTU of 12 was shown to be 12.5%. These results of non-uniform exchanger channels agree with previously conducted experimental results.

In this thesis, a numerical model for coupled heat and moisture transfer in a run around membrane energy exchanger (RAMEE) with a liquid desiccant as a coupling fluid is developed. The numerical model is two dimensional, transient and is formulated using the finite difference method with an implicit time discretization. The model for the case of only heat transfer for a single heat exchanger is compared to an available analytical solution and good agreement is obtained. It is shown that the discrepancy between the numerical and theoretical dimensionless bulk outlet temperature of the fluids is less than 4% during the transient period. The model is also validated for the case of simultaneous heat and moisture transfer using experimental data measured during the laboratory testing of a RAMEE system. The results for both sensible and latent effectiveness showed satisfactory agreement at different operating conditions. However, there are some discrepancies between the simulation and the experimental data during the transient times. It is proposed that these discrepancies may be due to experimental flow distribution problems within the exchanger. The maximum average absolute differences between the measured and simulated transient effectivenesses were 7.5% and 10.3% for summer and winter operating conditions, respectively.<p> The transient response of the RAMEE system for step changes in the inlet supply air temperature and humidity ratio is presented using the numerical model. In addition, the system quasi steady state operating conditions are predicted as the system approaches its steady state operating condition. The effect of various dimensionless parameters on the transient response is predicted separately. These included: the number of heat transfer units, thermal capacity ratio, heat loss/gain ratio, storage volume ratio and the normalized initial salt solution concentration. It is shown that the initial salt solution concentration and the storage volume of the salt solution have significant impacts on the transient response of the system and the heat loss/gain rates from/to the circulated fluid flow can change the system quasi steady effectiveness substantially. The detailed study of the transient performance of the RAMEE is useful to determine the transient response time of the system under different practical situations.