Electricity supply and use among rural and peri-urban households and small firms in Nigeria

Improving access to energy services among the underserved requires understanding the status quo in energy access and estimating future energy requirements of energy service provision. In this paper, we present a novel survey dataset collected in 2021 within the framework of the PeopleSuN project. Across three Nigerian geopolitical zones, a total of 3,599 households and 1,122 small and medium-sized enterprises were surveyed. The sample is representative of grid-electrified regions of each zone, excluding urban centres. Our surveys collect data on demographic and socioeconomic characteristics, energy access and supply quality, electrical appliance ownership and usage time, cooking solutions, capabilities, and preferences. We encourage academic use of the data presented and suggest three avenues of further research: (1) modelling appliance ownership likelihoods, electricity consumption levels and energy service needs in un-electrified regions; (2) modelling the integration of decentralised renewable and battery storage solutions to address high usage of diesel generators in peri-urban regions; (3) exploring broader issues of multi-dimensional energy access, access to decent living standards and climate vulnerability.Comment: Revised edition: Summary statistics moved to the end. Related datasets review table added. More technical details on data collection adde

Integrated Fluid Dynamic Vibration Absorber for Mobile Applications

The setup of a suspension always leads to a compromise between comfort and safety. In order to counteract this in a passive approach, one could attach a structural extension in the form of a dynamic vibration absorber to the axle. Thus, energy of the wheel vibrations is diverted into the vibration absorber instead of the body. In comparison to a classic dynamic vibration absorber, which is not in the sense of lightweight construction due to the additional mass, our Fluid Dynamic Vibration Absorber (FDVA) reduces the dynamic mass by using a hydrostatic transmission

Design and realization of an adjustable fluid powered piston for an active air spring

In this paper, we present a new compact hydraulic linear actuator. The concept is developed to change the rolling piston diameter of an active air spring during usage. By doing so, the air spring can actively apply pressure and tension forces. The actuator is designed for small movements at high forces. It is insensitive to side forces, which are introduced by the bellows rolling on the rolling piston of the air spring. A diaphragm sealing is used to minimize friction. Hence a precise adjustment of small displacements at high dynamics is possible and the system is completely leakage-free. We describe the design and development of this actuator and show first measurement results from preliminary tests to show its functionality

Active Pneumatic Suspension for Future Autonomous Vehicles: Design, Prove of Concept and Hardware-in-the-Loop Simulations

In this article, we present a new concept of an active air spring, which can apply pressure and tension forces independently of its deflection. The active strut mitigates body oscillations and improves the driving comfort making it attractive for autonomous driving to avoid motion sickness. The model of the active air spring system and the controller design are described. Furthermore, the suitability of the actuator concept for use in an active chassis is shown. Finally, we show results of hardware-in-the-loop simulations

SHEP: An Innovative Language to create and evaluate Optimization Programs for Pump Systems

Planning a pump system is a difficult task. Many different load profiles (scenarios) are given and have to be supported by the system. You can choose from a wide range of pumps and fittings to include them in the system. Many configurations of the chosen components have to be considered for this task. Therefore, an exponential number of possible systems can be imagined, more than a system designer can all think of. From this set of possible systems, it is hard to find the optimal system with minimal power consumption, acquisition costs or maintenance costs. Partners of this project developed a mathematical optimization program to compute this optimal pump system [1]. But such an optimization program is hard to read and to understand. Therefore, a domain specific language was designed to generate this optimization program. The language includes among others pump specifications, a selection of components to be used, their connections and different load profiles. The generated program is then solved by external software tools and evaluated to show the optimal system in a simulation model. The generated optimization program is analyzed to achieve user friendly feedback about feasibility of a system with the specific requirements. This paper presents some features of the language to proof that it is possible to specify a pumping system optimization scenario in a readable manner. Pumps are described by their characteristics, connection types and their costs. Characteristics are automatically linearized for a detailed model of the available operation points of the pump. If it is not possible to configure a system based on the given constraints, an error report will be generated indicating the problem in the original specification. For example, there would be an error message if the required pressure cannot be achieved by only using the given pumps. Another approach of this work is to evaluate the results of the optimization program solver. The result of the solver is a set of variables with their values. From this information a simulation model next to a layout of the cost optimal pump system are generated. In summary this work makes the power of mathematical optimization methods usable for a wide range of users. It is easy to plan an energy optimal system with the presented tool which supports all requirements. Compiler technologies can analyze the planned system and give the user a readable feedback for his work. Also it is possible to generate faster solvable optimization programs than normal crafted programs

Reconstructing the Scattering Matrix from Scanning Electron Diffraction Measurements Alone

Three-dimensional phase contrast imaging of multiply-scattering samples in X-ray and electron microscopy is extremely challenging, due to small numerical apertures, the unavailability of wavefront shaping optics, and the highly nonlinear inversion required from intensity-only measurements. In this work, we present a new algorithm using the scattering matrix formalism to solve the scattering from a non-crystalline medium from scanning diffraction measurements, and recover the illumination aberrations. Our method will enable 3D imaging and materials characterization at high resolution for a wide range of materials

Luftdämpfung als zukunftsweisende Technologie im Nutzfahrzeugbereich: Optimale Auslegung eines Luftfederdämpfers

Die Auslegung und Abstimmung eines Luftfederdämpfers (LFD) ist sehr komplex. In dieser Veröffentlichung wird gezeigt, wie Optimierungsmethoden dafür genutzt werden können. Das allgemeine Vorgehen dabei wird exemplarisch an der Vorauslegung eines Zweikammer-LFD von SAF-HOLLAND für eine Trailerachse gezeigt. Zusätzlich wird ein analytischer Ansatz präsentiert, mit dem die maximale Radvergrößerungsfunktion anhand einer Energiebetrachtung im Viertelfahrzeug abgeschätzt werden kann. Dadurch wird der Einfluss einzelner Parameter auf die Bedämpfung des Rades offensichtlich

Lebensdauer als Optimierungsziel : Algorithmische Struktursynthese am Beispiel eines hydrostatischen Getriebes

Verfügbarkeit und Nachhaltigkeit sind wichtige Anforderungen bei der Planung langlebiger technischer Systeme. Meist werden bei Lebensdaueroptimierungen lediglich einzelne Komponenten vordefinierter Systeme untersucht. Ob eine optimale Lebensdauer eine gänzlich andere Systemvariante bedingt, wird nur selten hinterfragt. Technical Operations Research (TOR) erlaubt es, aus Obermengen technischer Systeme automatisiert die lebensdaueroptimale Systemstruktur auszuwählen. Der Artikel zeigt dies am Beispiel eines hydrostatischen Getriebes

Designing a Feedback Control System via Mixed-Integer Programming

Pure analytical or experimental methods can only find a control strategy for technical systems with a fixed setup. In former contributions we presented an approach that simultaneously finds the optimal topology and the optimal open-loop control of a system via Mixed Integer Linear Programming (MILP). In order to extend this approach by a closed-loop control we present a Mixed Integer Program for a time discretized tank level control. This model is the basis for an extension by combinatorial decisions and thus for the variation of the network topology. Furthermore, one is able to appraise feasible solutions using the global optimality gap