18 research outputs found
Milian Lauritz Andreasen
No full textHead and shoulders portrait of Milian Lauritz Andreasen. Andreasen was a Seventh-day Adventist theologian, pastor and author. He was one of the Seventh-day Adventist church's most prominent theologians during the 1930s and 1940s. Andreasen held to the belief that Christians can overcome sin, known popularly as Last Generation Theology, controversial for its views on atonement and salvation. Andreasen became well known for his protests against Seventh-day Adventist church leaders during the last years of his life. Andreasen served as president of the Greater New York Conference (1909 - 1910), president of Hutchinson Theological Seminary (1910 - 1918), dean of Atlantic Union College (1918 - 1922), dean of Washington Missionary College (now Washington Adventist University) (1922 - 1924), president of the Minnesota Conference (1924 - 1931), president of Union College, Nebraska (1931 - 1938), and field secretary of the General Conference (1941 - 1950). He taught at the Seventh-day Adventist Theological Seminary (now located at Andrews University) from 1937 - 1950
Milian Lauritz Andreasen
No full textHead and shoulders portrait of Milian Lauritz Andreasen. Andreasen was a Seventh-day Adventist theologian, pastor and author. e was one of the Seventh-day Adventist church's most prominent theologians during the 1930s and 1940s. Andreasen held to the belief that Christians can overcome sin, known popularly as Last Generation Theology, controversial for its views on atonement and salvation. Andreasen became well known for his protests against Seventh-day Adventist church leaders during the last years of his life. Andreasen served as president of the Greater New York Conference (1909 - 1910), president of Hutchinson Theological Seminary (1910 - 1918), dean of Atlantic Union College (1918 - 1922), dean of Washington Missionary College (now Washington Adventist University) (1922 - 1924), president of the Minnesota Conference (1924 - 1931), president of Union College, Nebraska (1931 - 1938), and field secretary of the General Conference (1941 - 1950). He taught at the Seventh-day Adventist Theological Seminary (now located at Andrews University) from 1937 - 1950
Milian Lauritz Andreasen
No full textDanish-born administrator, educator, author; A.B. University of Nebraska (1920); M.A. University of Nebraska (1922). Following his ordination in 1902 he held varied administrative positions: president of the Greater New York Conference (1909-1910), president of Hutchinson Theological Seminary (1910-1918), dean of Union College (1918-1922), dean of Washington Missionary (now Columbia Union) College (1922-1924), president of the Minnesota Conference (1924-1931), president of Union College (1931-1938), and field secretary of the General Conference (1941-1950). From 1938 to 1949 he taught at the SDA Theological Seminary in Washington, D.C. Autographed.50.026 K
Thermodynamic, Economic and Maturity Analysis of a Carnot Battery with a Two-Zone Water Thermal Energy Storage for Different Working Fluids
No full textThe rising share of renewable energies leads to increased fluctuations in electrical power supply. One possibility to shift the surplus energy based on demand is a Carnot battery (CB). A CB uses a heat pump or resistance heater to convert and store thermal energy into electrical energy. Later, the stored thermal energy is converted back into electrical energy using a heat engine. This study investigates a CB with a two-zone tank for thermal energy storage. A transcritical process with CO2 is applied for charging, while discharging employs a transcritical process with CO2 and six refrigerants operating in a subcritical process. The transcritical process with CO2 and the four most promising subcritical processes are compared regarding round trip efficiency and levelized cost of electricity (LCOE) depending on the pinch points 5 K and 1 K in the heat exchangers. Additionally, the technology readiness level (TRL) is determined for these configurations. The results show round-trip efficiencies between 11.3% and 33.5% and LCOEs ranging from EUR 0.95 (kWh)−1 to EUR 2.09 (kWh)−1 for the considered concepts with TRLs of up to six
Market-based optimization of the Energy-to-Power ratio of a latent thermal energy storage unit based Carnot Battery
No full textThe volatile electricity generation from renewable energies creates the need for electricity storage technologies which, unlike the pumped hydroelectric energy storage established to date, are not tied to geographical conditions. The emerging technology of pumped thermal electricity storage (PTES) is one such alternative. PTESs belong to the group of Carnot Batteries.
Using a price-taker approach with perfect daily foresight, this study determines the achievable contribution margin of a 5MW generic storage in the German day-ahead market by exclusively exploiting daily price spreads. Based on real data from various phase change materials, the investment costs for PTES with a latent thermal energy storage (LTES) unit can be determined as a function of their energy-to-power ratio (E/P-ratio). By comparing the achievable contribution margins and investment costs, the most economical E/P-ratio can be identified. The result is a cost-optimal E/P-ratio that depends on the year, the round-trip efficiency, the coefficient of performance, and the powerrelated purchased equipment cost. For this purpose, both historical and future years were examined, whereby an agent-based market model was used to simulate the future electricity price time series. Oxalic acid dihydrate proved to be the optimal phase change material for all round-trip efficiencies investigated. It turned out that, under the assumed boundary conditions, no PTES enables an economically attractive operation at round-trip efficiencies between 30 % and 70 %. The configurations closest to an economically attractive operation have E/P-ratios of at least 4 h related to the charging duration at half discharging duration
Derivation of the Thermal Conductivity in a Latent Thermal Energy Storage Unit for Use in Simplified System Models
No full textLatent Thermal Energy Storages (LTES) can store thermal energy in a narrow temperature range. Therefore, they are favorable for integration into Rankine-based Carnot Batteries. For the design of such systems, simulations based on accurate models are desirable. However, physical phenomena such as natural convection in LTES units cannot be modeled directly in transient system models. Simplified models are required. Therefore, the objective of this work is to derive simplified LTES unit models for use in system models. In transient simulations the state of charge of the LTES influences its temperature profile. The temperature profile depends on the geometry of the LTES unit. Therefore, the geometry must be considered to model the transient behavior of an LTES unit. The LTES unit under investigation has a shell and tube heat exchanger structure. The phase change material (PCM) is located between the hexagonal fins and in the space between the finned tubes. Aluminum fins are used. They have a high thermal conductivity and thus compensate for the low thermal conductivity of the sodium nitrate used as PCM. The interaction between fins and PCM is complex. Therefore, a numerical approach can be used to gain insight into the behavior of the LTES unit. To transfer the results of a complex model to a simplified model where fins and PCM are not considered individually, the effective thermal conductivity of a single finned tube can be used to approximate the performance of the LTES unit. In this study, a model of a section with a single finned tube is developed using the COMSOL software. The effective thermal conductivity of the system is determined by varying the effective thermal conductivity in a simplified model and comparing the results with reference cases based on a complex modeling approach. The results can serve as model input for simplified system models of Carnot Batteries, among others
Comparison of Stationary and Transient Simulations of a Latent Thermal Energy Storage Unit in a Carnot Battery
No full textThe expansion of renewable energies is leading to an increasing fluctuation in electricity generation. Besides established concepts such as pumped hydroelectric energy storage for balancing demand and generation, the so-called Carnot battery (CB) is an emerging technology to store electrical energy. A CB consists of a heat pump, a thermal energy storage unit, and a heat engine. The heat pump is used for the charging process, which converts electrical energy to thermal energy. After storing the thermal energy in the thermal energy storage unit, the heat engine is used to discharge the storage unit and supply electrical energy. As the competition on the electricity market is high, an optimal configuration has to be found to achieve an economically viable CB. So far, many different CB systems have been investigated using different configurations including different storage units. Latent thermal energy storage (LTES) units are less explored than sensible thermal energy storage units, but they are promising due to their relatively constant operating temperature and high energy densities. Therefore, CBs based on LTES are examined in this study. The LTES is a component which should be modeled transiently, as the phase change material (PCM) undergoes a phase change during charging and discharging. Within an optimization problem, the time to carry out a transient simulation exceeds the available computing capacity. Therefore, the transient behavior must be approximated by a stationary simulation. The deviation between stationary and transient results must be quantified in order to assess the uncertainty. This study investigates the difference between two stationary simulations of a CB based on an LTES unit with erythritol as PCM and the results of a transient simulation of this configuration. The simulations are compared with regard to the coefficient of performance, the efficiency of the heat engine, and the round-trip efficiency. It turns out that both stationary simulations are not capable to approximate the transient simulation satisfactorily. Therefore, the use of several stationary simulations instead of just one stationary simulation could be investigated in the future to achieve the desired objective. For all simulations the commercial software EBSILON®Professional is used
Introduction to property theory - the fundamental theorems
No full textThe market system consists of a price mechanism, built on the foundation of a system of property, and contract. In many developing, and transition economies, the market system functions poorly. In many cases, if not most, the malfunctioning is not simply in the price system (for example, anti-competitive activities), but in the underlying property system (such as contracts being breached, and externalities in the sense of transfers not covered by contracts). Economic theory tends to take the functioning of the system of property, and contract for granted, and focuses on the operation of the price mechanism. Property theory focuses on the underlying system of property, and contract. In this paper, the author inaugurates the mathematical treatment of property theory.In contrast with earlier work in"law and economics", and the"new institutional economics", this approach uses principles drawn from jurisprudence, and does not attempt to reduce"law"to"economics"in the sense of efficiency considerations, such as the minimization of transaction costs. The main results are the two fundamental theorems of property theory that are analogous to the two fundamental theorems of price theory that, in essence, state that: 1) A competitive equilibrium is Pareto optimal. 2) Given a Pareto optimal state, there exists a set of prices such, that a competitive equilibrium at those prices would realize that Pareto optimal state.Environmental Economics&Policies,Labor Policies,Banks&Banking Reform,Municipal Housing and Land,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Economic Theory&Research,Municipal Housing and Land,Land and Real Estate Development
Sensing Domesticity: From Mine to Mine
No full textFrom Mine to Mine is a research and design project that confronts the concept of the house and the domestic with its emerging context of data transmission and resource extraction. In the middle of the Atacama desert in Chile, the house of the miner is confronted with the physical outgrowth of our global data industry: Copper, the material underlying any kind of digital connection, is extracted in the world‘s biggest open-pit mine, while the mining industry is destructing and contaminating a whole territory.Thinking towards a time of copper depletion, From Mine to Mine, envisions in three chapters transitions for these copper landscapes - turning them from destructive into productive ones while giving agency to the house of the miner itself. From there, the miner of the future enters remotely through screens the three chapters - “The Toxic Forest“, “The Baquedano Oasis“ and “The London Mine“ - all mines in their on right, that materially and programmatically feed into the house. This way, the house becomes both consumer and constructor of a context in trans-ition, a context that is being “mined“ trans-territorially, trans-temporally and trans-disciplinarily.Architecture, Urbanism and Building Sciences | Explorela
Concession contract renegotiations : some efficiency versus equity dilemmas
No full textThe authors analyze the possibility of tradeoffs between efficiency and equity as well as the possibility of distributional conflicts in the context of renegotiation of infrastructure contracts in developing countries. To do so, they present a model in which contracts are awarded by auctioning the right to operate an infrastructure service to a private monopoly, and consider the possibility of renegotiation. To identify the potential sources of tradeoffs, they trackthe possible outcomes of different renegotiation strategies for the monopoly running the concession and for the two groups of consumers-rich and poor-who alternate in power according to a majority voting rule. Among the model? most important policy implications is this: if having firm-driven renegotiations is a major concern, efficiency should not be the only consideration in selecting an operator. Indeed, consumers may want to award the concession to a less efficient firm if that would reduce the probability of renegotiation, since a lower probability of firm-driven renegotiations (due to demand shocks, for example) is associated with higher welfare for all service users.Environmental Economics&Policies,Labor Policies,Markets and Market Access,Economic Theory&Research,International Terrorism&Counterterrorism,Economic Theory&Research,Environmental Economics&Policies,Markets and Market Access,Access to Markets,International Terrorism&Counterterrorism
