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Engl. Broschur. 40 S. mit Abb. - 23,5 x 15,5. Einband etwas berieben, sonst gut erhalten. Sprache: Deutsch Gewicht in Gramm: 124.

Paperback. Zustand: New. The need for artificial intelligence systems that are not only capable of mastering complicated tasks but also of explaining their decisions has massively gained attention over the last years. This also seems to offer opportunities for further interconnecting different approaches to artificial intelligence, such as machine learning and knowledge representation.This work considers the task of learning knowledge bases from agent behavior, with a focus on human-readability, comprehensibility and applications in games. In this context, it will be presented how knowledge can be organized and processed on multiple levels of abstraction, allowing for efficient reasoning and revision. It will be investigated how learning agents can benefit from incorporating the approaches into their learning processes.Examples and applications are provided, e.g., in the context of general video game playing. The most essential approaches are implemented in the InteKRator toolbox and show potential for being applied in other domains (e.g., in medical informatics).

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Paperback. Zustand: new. Paperback. The key measure to mitigate climate change is the reduction of greenhouse gas emissions. Hereby, energy-intensive industry plays a key role due to its substantial greenhouse gas emissions. A substantial share of these greenhouse gas emissions is caused by energy supply. Thus, energy supply needs to be more efficient in industry.In large industrial sites, on-site energy systems often supply production systems. Both systems thereby optimize their operation with respect to an objective such as operational cost or revenue. This thesis provides optimization methods for these large industrial sites. The optimization methods reflect two relationships between both systems: Both systems can either follow the same objective or system-specific objectives. The same objective exists, e.g., if both systems belong to one company. System-specific objectives exist, e.g., if both systems belong to different companies.For the case that both systems follow the same objective, a method is presented for the integrated synthesis of both systems. For the same case, a method is presented for integrated scheduling to provide control reserve. For the case that energy and production systems have system-specific objectives, two cases are distinguished: incomplete and complete information exchange. For incomplete information exchange, an optimization method is introduced for the coordination between a single energy and a single production system. This optimization method is then extended to multiple energy and multiple production systems. For complete information exchange between the systems, a bilevel problem is formulated. For solving the bilevel problem, an existing solution algorithm is adapted.All methods presented in this thesis are applied to case studies, and advantages and disadvantages are examined. The case studies show that no method provides the optimal solution for the production system in all identified relationships between the systems. Thus, depending on the case at hand, the respective optimization method has to be applied. Overall, this thesis presents optimization methods for all identified relationships between energy and production systems. Thus, this thesis enables the selection of a suitable optimization method for all kind of production systems with decentralized energy supply. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

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Zustand: As New. Unread book in perfect condition.

Zustand: As New. Unread book in perfect condition.

Zustand: As New. Unread book in perfect condition.

Zustand: As New. Unread book in perfect condition.

PAP. Zustand: New. New Book. Shipped from UK. Established seller since 2000.

Paperback. Zustand: new. Paperback. Smoking chimneys are a symbol for environmental impacts of industrial processes. Indeed, industrial processes are major contributors to environmental problems such as global warming. Beyond emission-related problems, industrial processes deplete limited resources because they require raw materials. Raw materials are directly linked to costs, emission-related impacts cause indirect expenditures, e.g., through the European emissions trading scheme (EU-ETS) for greenhouse gas emissions. Therefore, industrial enterprises seek to reduce costs by reducing environmental impacts of their processes.Two well-known strategies for reducing environmental impacts of industrial processes are process integration and recycling. Process integration establishes interconnections between formerly separate processes by utilizing co-products. Process integration thereby relies on unit processes with multiple products, so-called multi-product processes. Similarly, recycling uses waste as raw material for new products. But neither process integration for recycling guarantee reduced environmental impacts. E.g., recycling may cause more impacts than waste disposal. Decision makers thus need a holistic method for comparing environmental impacts from multi-product processes.This work investigates methods for comparisons of industrial multi-product processes. The environmental impacts of multi-product processes can be analyzed using life cycle assessment (LCA). LCA studies all environmental impacts of all processes involved in a procucts entire life cycle. Due to ist holistic approach, LCA identifies shifting of environmental problems between processes and between different types of environmental impacts. Results of LCA-studies can thus help avoiding such problem shifting. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. In 2007 the International Telecommunication Union, Radiocommunication Sector (ITU-R) published evaluation guidelines for future mobile broadband radio networks including a minimal VoIP capacity that the IEEE 802.16m WiMAX system had to meet, proven by system level simulation. These evaluation guidelines are the foundation of this work that shows that relayenhanced 4G networks do not only meet the requirements but exceed them by far. The key-requirement for packet based VoIP services that has been set in the evaluation guidelines demands that the end-to-end packet delay of at least 98% of user data traffic stays below 50 ms.Since 2011 proposals of ComNets to implement relays into mobile radio networks to increase system capacity are part of all 4G systems (LTE and WiMAX). This work investigates the voice over IP (VoIP) capacity of the relay-enhanced WiMAX system by system simulation. The work presents a modular approach that has been developed by my colleagues and myself to implement the WiMAX protocol stack, also known as WiMAC, into the openWNS simulator. The approach is based on atomic protocol functions that are bound to so called FU and interconnected in a network of functional units (FUs) and thereby implement the WiMAX protocol bit-by-bit. Besides the performance evaluation of VoIP services based on the ITU-R scenarios and channel model, this work also determines the optimal radio resource configuration for up- and downlink and furthermore investigates the impact of RS location on system capacity. Core functions of the simulator are being validated by comparison of equivalent results of other simulators.Cumulative distribution functions of the end-to-end delay of VoIP user data packets, determined by simulation show that relays double the carried VoIP traffic load compared to a scenario without relay stations (RSs) due to the improved prediction of the uplink channel state that is the bottleneck of the system.The performance enhancement is a surprise since relays increase the end-to-end packet delay and packet error due to an additional transmission compared to conventional single-hop operation. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. In recent years, the conversion of CO2 to basic chemicals with one carbon atom (C1-chemicals) such as methane and methanol has gained increasing interest. The major motivation for the utilization of CO2 is the reduction of global warming and fossil depletion impacts. However, these reductions are not guaranteed because all C1-chemicals require hydrogen besides the abundantly available CO2. Thus, the goal of this thesis is the life cycle assessment of CO2-based C1-chemicals (methane, methanol, carbon monoxide and formic acid). The assessment is based on a system-wide perspective, which means that for limited resources such as renewable electricity also the utilization of the limited resources is in other processes is considered.First of all, the CO2-based processes are compared to fossil-based processes for C1-chemicals. Formic acid has the highest potential to reduce global warming and fossil depletion impacts followed by carbon monoxide, methanol and methane. Even if hydrogen is supplied by fossil-based steam reforming, formic acid reduces global warming and fossil depletion impacts. All other CO2-based C1-chemicals require hydrogen from electrolysis using renewable electricity.In the following, the supply of hydrogen by electrolysis is analyzed in more detail. The CO2-based processes for carbon monoxide and methane required about 60 % and 88 % renewable electricity (in 2020 in the EU-27) to reduce global warming impacts compared to the fossil-based processes.If 100 % renewable electricity is used, all CO2-based C1-chemicals reduce global warming and fossil depletion impacts compared to the fossil-based processes. For the assessment of these reductions, also alternative utilization options for renewable electricity (Power-to-X) are analyzed such as electricity storage systems, battery electric vehicles and heat pumps. The highest reductions per electricity used are achieved for heat pumps followed by battery electric vehicles and electricity storage systems. Then, the CO2-based C1-chemicals follow.Since renewable electricity is used more efficiently outside the chemical industry, also biomass-based methane and methanol are analyzed. The utilization of biomass achieves the highest reductions if coal-fired power plants are substituted followed by the production of methanol. For methanol and methane, the yield per biomass can be increased if additional hydrogen is used. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. Worldwide heating and cooling demand will rise significantly over the next decades. Adsorption energy systems, namely adsorption chillers and heat pumps, have the potential to provide parts of this demand environmentally friendly by employing solar heat or waste heat.Designing adsorption energy systems is challenging due to the following reasons: (1) intrinsic dynamics, (2) multi-objectiveness, (3) large variety in design parameters, (4) strong influence of control, and (5) a large impact of input parameters such as temperatures. In many studies, these effects have been investigated separately by conducting sensitivity analyses. To explore also the interactions between design, control, and input parameters, a simultaneous optimisation approach is presented and exemplified in this thesis.Key to simultaneous optimisation are fast simulation models which capture the effects of all optimisation parameters. To quickly model new advanced adsorption energy systems, an object-oriented, dynamic-model library is developed in the programming language Modelica.To conduct a simultaneous optimisation of design and control, a multi-objective optimal control problem is formulated. This optimal control problem includes the system dynamics which are captured in the dynamic process model. Additionally, point and path constraints are formulated, ensuring cyclic steady state. The multiobjectiveness is taken care of by employing the constraint method. The resulting single-objective optimal control problem is solved by the efficient multiple shooting algorithm MUSCOD II.The developed optimisation framework is used to rigorously analyse the interaction between adsorber-bed design, component sizing, thermodynamic cycle, and control. The framework is also used to investigate the effect of the objective function and of varying input temperatures on design and control. The multi-objective optimisation results are used to discuss the trade-off between efficiency and power density by employing the Pareto frontier.Finally, simulation models and optimisation framework are used to set up a model predictive control (MPC). The MPC allows to identify and adjust the optimal control parameters based on varying input conditions. Based on these results, new heat-flow based heuristics are developed, which lead to a Pareto-optimal operation of one-bed adsorption chillers. Both MPC and heuristics are applied experimentally to a one-bed chiller. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. In recent years, spectroscopy has developed into an increasingly valuable tool to determine the composition of mixtures; for scientific questions as well as for the industry. The increasing use of spectroscopy raises the question how to best use the obtained data. For the analysis of spectral data, the method of Indirect Hard Modeling (IHM) has been established besides statistical methods like PLS. IHM is a nonlinear method that can therefore efficiently treat nonlinear effects such as peak-shifts. In the present work, the IHM method is expanded to increase its applicability.IHM treats nonlinear effects in the spectral evaluation. Therefore, the direct proportionality between the concentration and the Raman signal of a component can be used for calibration. The resulting linear calibration model allows for reliable extrapolation. Thus, IHM can be used to study reactive systems, even if only binary subsystems can be used for calibration. However, thermodynamic systems with intermediates can so far only be calibrated by using thermodynamic models. In this work, a method is established that calibrates a reactive system with intermediates only based on the reaction mechanism as well as stoichiometry and electroneutrality.Spectral backgrounds, e.g., fluorescence, can be treated by a spectral pretreatment or via background models. However, spectral backgrounds are still a common source of error in IHM. Derivatives have long been used very effectively in statistical methods. Therefore, IHM is adapted so that it becomes possible to evaluate the first derivative of spectra.The calibration of IHM is mostly limited to the relative spectral intensities of the involved components. In the present work, a method is presented that uses the information in the calibration spectra more thoroughly. For this purpose, nonlinear effects are parametrized as a function of concentration.The commonly used peak profiles do not reflect the physical reality at a detector very well. As a result, narrow modelled peaks may change their apparent intensity if they are shifted. To correct these shortcomings, a new peak model is proposed in this work that is more closely aligned to the physical reality of a detector. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. During the last 25 years, most of the communication systems have been converted to purely digital technology, although the transmitted content mostly is analog by nature. The principal advantages of digital communication are compression by source encoding, bit error protection by channel coding and robust transmission over noisy channels by appropriate modulation. Digital systems are usually designed for worst case channel conditions. However, often the channel quality is much better, which is not reflected in an improved end-to-end transmission quality due to inevitable quantization noise produced by the source encoder.In this thesis, the focus is set on systems which: are not purely digital anymore benefit from increasing channel qualities and avoid the saturation effect using discrete-time, continuous-amplitude techniques.In the first part, purely analog, i.e., discrete-time and continuous-amplitude transmission systems are considered with linear or nonlinear components. Theoretical performance limits are discussed and a new rate-distortion upper bound is derived which can be evaluated semi-analytically. The performance of linear transmission systems is derived analytically while simulations assess several nonlinear systems including the famous Archimedes spiral. A new class of nonlinear discrete-time analog coding systems, i.e., the Analog Modulo Block Codes (AMBCs) is developed. One important observation is that nonlinear discrete-time, continuous-amplitude systems can be decomposed into a discrete and a continuous-amplitudes part. The considered systems exhibit a considerable gap to capacity but they all circumvent the saturation effect due to the continuous-amplitude components.In the main part of the thesis, these findings are turned into a design principle. Hybrid Digital-Analog (HDA) transmission systems consist of separate digital and analog branches while each is constructed independently. By combining both worlds digital and continuous-amplitude transmission new concepts emerge which fuse their advantages: capacity achieving performance in the digital branch with a huge variety of conventional digital codes plus avoiding the saturation effect in the analog branch. The performance of HDA systems is assessed theoretically as well as by simulations. These Hybrid Digital-Analog (HDA) transmission systems outperform both purely digital and continuous-amplitude concepts. HDA transmission is an attractive solution for wireless systems such as microphones, loudspeakers or distributed sensors. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. Big data raises new opportunities for deep insights and supporting decision-making. To seize these opportunities, methods that derive useful knowledge from large amounts of data are needed. Such methods can help meet urgent challenges in many fields. An urgent challenge for energy systems is the necessary transformation towards sustainability to mitigate climate change. One crucial aspect of this challenge is a permanent optimal operation of energy systems. In principle, mathematical optimization can best determine the optimal operation of energy systems. However, manual model generation and operational optimization of energy systems are time-consuming and can thus prevent an application of mathematical optimization in practice. This thesis presents methods that use measured data to automatically generate mathematical models of energy systems to tackle the challenge of time-consuming model generations. Additionally, methods are presented that accelerate the operational optimization of energy systems. Regarding model generation, the presented data-driven methods solve the trade-off between accuracy and computational efficiency of the energy system model by weighting each component model by its role in the overall system. Thereby, the methods automatically generate energy system models that allow for accurate and computationally efficient optimization.To accelerate the operational optimization of energy systems, we present two methods that decompose the complex operational optimization problem into smaller subproblems. The methods provide high-quality solutions. The first method employs expert knowledge about the individual energy system to significantly accelerate the operational optimization while retaining an excellent solution quality.The second method applies artificial neural nets to solve the operational optimization in a reliably short time while offering a high solution quality. Overall, the methods presented in this thesis enable a broader application of mathematical optimization for energy systems. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

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Paperback. Zustand: new. Paperback. This thesis studies the congestion problem at the Medium Access Control (MAC) layer of the IEEE 802.11p system in highway scenarios using an analytical approach. Using the Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) protocol, the IEEE 802.11p system suffers from the hidden station problem. This thesis provides formal definitions for the hidden station condition and the hidden station problem and develops an analytical methodology for CSMA protocols to investigate the interaction between stations in mutual channel sensing range and hidden to each other. Analytical models are developed for broadcast communication using the generic CSMA protocol and the IEEE 802.11p MAC protocol with a one-dimensional (1-D) homogeneous network topology. Simulation studies prove the accuracy of the models in analyzing the reliability performance and the efficiency performance of CSMA broadcast communication with hidden stations.The performance of Cooperative Awareness Message (CAM) in IEEE 802.11p network is analyzed for highway scenarios using the developed analytical models. The study reveals that in a hidden station scenario the reliability performance of the CAM broadcast communication deteriorates with increased topological distance between the transmitter and the receiver. This study provides quantitative analysis of this performance with respect to network density, frame length, traffic load and settings of the IEEE 802.11p MAC protocol. Analysis of the mean update interval of CAM at a receiver vehicle discovers though in general the performance degrades with increased network density, the update interval of CAM frames from a particular vehicle in the vicinity of the receiver, e.g. with a topological distance less than 8 between the transmitter and the receiver, can be easily maintained below 1 second by using control mechanisms like transmit power control, transmit rate control and link control. The analytical models developed in this work provide quantitative guidance on optimizing protocol parameters and utilization of these control mechanisms. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. In this thesis, two novel synthesis methodologies are proposed to facilitate the use of optimization for efficient and reliable DESS synthesis, thus making optimization accessible for practitioners: The automated superstructure-based and the superstructurefree synthesis methodology. The proposed methodologies avoid both the a priori definition of a superstructure and the manual definition of many technology-specific replacement rules while accounting for the major characteristics inherent to DESS synthesis problems. The superstructure-based framework (chapter 4) relies on an algorithm for automated superstructure-generation. The method employs a successive superstructure expansion and optimization strategy that continuously increases the number of units included in the superstructure until the optimal solution is identified. The superstructure-free approach (chapter 5) combines evolutionary optimization and deterministic optimization for simultaneous alternatives generation and optimization. A knowledge-integrated mutation operator is proposed that relies on a hierarchically-structured graph, the so-called energy conversion hierarchy (ECH). The ECH efficiently defines all reasonable replacement rules, thus avoiding their manual definition. The mutation operator performs structural replacements for the evolutionary generation of solution alternatives. Both synthesis methodologies use a generic component-based modeling framework, thus making the methodologies independent of the employed mathematical programming formulation. In this thesis, a robust MILP formulation is used that allows to simultaneously optimize the structure, sizing, and operation of distributed energy supply systems accounting for time-varying load profiles, continuous equipment sizing, economy of scale of equipment investment, and part-load equipment performance. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

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Paperback. Zustand: new. Paperback. Vapor-liquid equilibrium (VLE) data are of major importance for the chemical industry. Despite significant progress in predictive methods, experimental VLE data are still indispensable. In this work, we address the need for experimental VLE data. Commonly, the characterization of VLE requires significant experimental effort. To limit the experimental effort, VLE measurements are frequently conducted by synthetic methods which employ samples of known composition and avoid complex analytics and sampling issues. In contrast, analytical methods provide independent information on phase compositions, commonly based on sampling and large amounts of substance.In the first part of this work, we employ a synthetic method, the well-established Cailletet setup, to characterize the high pressure VLE of two promising binary biofuel blends. The Cailletet method serves as a state of the art reference method that enables collecting data of remarkable accuracy. However, extensive infrastructure is needed.In the second part, to avoid extensive infrastructure and overcome limitations of previous methods, we develop a novel analytical milliliter-scale setup for the noninvasive and efficient characterization of VLE: RAMSPEQU (Raman Spectroscopic Phase Equilibrium Characterization). The novel setup saves substance and rapidly characterizes VLE. Sampling and its associated errors are avoided by analyzing phase compositions using Raman spectroscopy. Thereby, volumes of less than 3 ml are sufficient for reliable phase equilibrium measurements. To enable rapid data generation and save substance, we design an integrated workow combining Raman signal calibration and VLE measurement. As a result, RAMSPEQU gives access to up to 15 pT xy-data sets per workday. RAMSPEQU is successfully validated against pure component and binary VLE data from literature.However, mixtures with only two components rarely depict real industrial applications. As the number of experiments increases strongly with a rising number of components, the efficient RAMSPEQU setup seems particularly suited for multicomponent systems. In the third part of this work, we employ the RAMSPEQU setup for the characterization of a quaternary system and its binary subsystems. 22 ml and 105 ml of the binary and quaternary mixtures are sufficient for an extensive VLE characterization.The RAMSPEQU setup and its integrated workow enable the characterization of multicomponent VLE while saving significant amounts of substance and laboratory time. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. The emerging interest on the application of vacuum interrupter (VI) in medium and even high-voltage application has led to increase of comprehensive and fundamental research on VIs. Application of these interrupters is however hindered by limitation of interrupting capability, when high-current anode phenomena occur.The goal of the work is to investigate the high-current anode phenomena using spectroscopic methods se well as electrical measurements. Different current waveforms, i.e. AC and DC pulses are applied. Moreover, the impact of vacuum interrupter properties, e.g. electrode diameter and geometries, contact materials, opening time and opening speed on the formation of high-current anode phenomena are investigated.The results reveal that the threshold current of the high-current anode formation is dominated by the current in case of high-frequency pulsed, whereas in case of pulsed DC, it is controlled by transferred charge.Along with typical and already known high-current modes, i.e. footpoint, anode spot, and intense modes, a new type of high current anode mode, anode spot type 2, is introduced. Anode spot type 2 is similar to the intense mode but it appears at larger gap length. In contrast to anode spot (anode spot type 1), both anode and cathode are active in case of anode spot type 2. The line emission intensities of all species increase near the anode and the cathode in case of anode spot type 2. The anode spot type 2 is examined by determining radiating density, ground state density and electron density which is about two times higher compared to anode spot type 1.Optical emission spectroscopy combined with high-speed camera imaging (video spectroscopy) is used to investigate the temporal and spatial distribution of Cu I, Cu II, and Cu III during discharge modes.The results show different patterns during discharge modes. The formation of anode plume, is investigated using video spectroscopy. Existence diagrams confirm that the anode plume appears always after the extinction of anode spot type 2 in case of CuCr electrodes before current zero. The results unfold that the emission from the inner part of anode plume is covered by atomic lines, whereas the outer part is dominated by ionic line radiation. Anode plume formation which is a result of shock effect in front of the anode shows that anode plume contracts first and then it expands. Radiating densities of atomic and ionic Cu lines, and temporal evaluation of temperatures inside the anode plume are determined during the formation of anode plume.The ground state density of Cr I before and after current zero is calculated for two cases; with and without anode plume using broadband absorption spectroscopy. The results point out that the ground state density after current zero is higher in case of anode plume. Moreover, during active phase the ground state density is higher in case of anode spot type 2 compared to anode spot type 1. Furthermore, the temporal evolution of ground state density of Cr I is calculated during high-current anode phenomena.A new electric arc model based on the existence diagram is proposed in this work. In contrast to conventional electric arc model, e.g. Mayr, Cassie, Habedank, Schavemaker, etc., this model can track or detect the arc voltage of vacuum arc even during anode spot type 2 and abrupt change in the arc voltage. Moreover, this model based on the existence diagram has a predictability characteristic. By providing the existence diagram to the model, the arc voltage can be traced in quite different interrupting current ranges. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

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Paperback. Zustand: new. Paperback. Terrestrial broadcast is traditionally realized over High Tower High Power (HTHP) networks which have been preserved in the transition from the analog PAL to the first generation of the digital DVB-T technology. The drawback of this traditional network design is its spectral inefficiency. The demand for providing more TV programs with HD quality as well as the increasing spectrum consumption of mobile internet services, with video streaming being one of the driving factors, necessitate a re-optimization of the current broadcast network and a more efficient allocation of frequencies.In this thesis, three options for a future frequency-efficient evolution and coexistence of terrestrial TV and mobile internet are specified and investigated: Transition from the current terrestrial broadcast with DVB-T to its successor DVB-T2 while retaining the HTHP network infrastructure Switch-over from DVB-T to DVB-T2 with transition to a Low Tower Low Power (LTLP) network infrastructure Utilization of the evolved Multimedia Broadcast/Multicast Service (eMBMS) within an existing LTLP LTE network.All three system concepts are evaluated in terms of bit error rate performance and system throughput. Additionally, coverage and total network transmit power are determined by system level simulations for different propagation models and network topologies. Although the emphasis of this thesis is on the evaluation of the performance and feasibility of the three scenarios from a technical point of view, political, regulatory, and economic considerations are addressed in short.In summary, all three options bear a huge potential for a significant reduction of the spectrum required for terrestrial broadcast. The introduction of DVB-T2 for terrestrial broadcast is a good compromise between performance, cost, and regulation. However, its full spectral potential can only be exploited in combination with LTLP network concepts. Furthermore, this thesis proves the importance of alternative terrestrial broadcasting concepts, which are highly beneficial for a further convergence of TV and mobile internet. The enhanced multimedia service eMBMS (LTE and 5G) represents an attractive solution for replacing or supplementing future terrestrial broadcast systems, especially for the distribution of personal and regional TV content. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Paperback. Zustand: new. Paperback. Diffusion is the rate-limiting mass transport step in many (bio)chemical processes. Diffusion data is therefore necessary to design unit operations, e.g., extraction. However, diffusion data on multicomponent mixtures in liquids are scarce, as diffusion measurements are intrinsically time-consuming and laborious. Also, several measurements are required for one diffusion coefficient matrix in a multicomponent mixture.Microfluidics promises to reduce experiment time and experimental effort, while Raman spectroscopy reduces the number of necessary experiments for multicomponent mixtures. To reduce the measurement effort for diffusion coefficients in multicomponent mixtures, microfluidics and Raman microspectroscopy were combined in this work for the first time for the measurement of diffusion coefficient matrices in multicomponent mixtures: Two liquids of different concentrations co-flow in parallel in a microfluidic H-cell, while changes of concentration due to diffusion are quantified locally using Raman microspectroscopy. From these changes of concentration, the diffusion coefficient matrix is determined in a least squares procedure using a convection-diffusion-model. Thereby, diffusion coefficient matrices can be determined from a single experiment, while the known initial concentrations together with quantitative Raman spectroscopy spare additional calibration measurements. The experiment takes less than 1h and the sample consumption is below 6mL.The developed method to determine diffusion coefficients was validated for binary and ternary systems. Additionally, new diffusion data was measured for a binary, a ternary and a quaternary system. Two and three experiments are sufficient to determine diffusion coefficient matrices with accuracy and precision for ternary and quaternary systems respectively. Systems used for validation agree with literature data. Thus, diffusion coefficient matrices of multicomponent mixture can be provided with small effort and in short time to enable the design of unit operations. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.