Taxonomy, Semantic Data Schema, and Schema Alignment for Open Data in Urban Building Energy Modeling

Urban Building Energy Modeling (UBEM) is a critical tool to provide quantitative analysis on building decarbonization, sustainability, building-to-grid integration, and renewable energy applications on city, regional, and national scales. Researchers usually use open data as inputs to build and calibrate UBEM. However, open data are from thousands of sources covering various perspectives of weather, building characteristics, etc. Besides, a lack of semantic features of open data further increases the engineering effort to process information to be directly used for UBEM as inputs. In this paper, we first reviewed open data types used for UBEM and developed a taxonomy to categorize open data. Based on that, we further developed a semantic data schema for each open data category to maintain data consistency and improve model automation for UBEM. In a case study, we use three popular open data to show how they can be automatically processed based on the proposed schematic data structure using large language models. The accurate results generated by large language models indicate the machine-readability and human-interpretability of the developed semantic data schema

controlling colloidal assembly and phase behavior via morphing energy landscapes

Controlling assembly of colloidal particles into different phases and microstructures could provide bases to understand and manufacture novel materials with non-trivial properties and numerous potential applications. A common strategy is to direct the assembly with prefabricated topographical or chemical patterns. This approach is useful in rapid assembly of massive materials but is inherently an irreversible process and is unable to achieve reconfigurable control. Field mediated self-assembly, on the other side, directs the process through interaction with external fields, including optical, magnetic, and electric, and provides a promising path for more sophisticated microstructures. One of the most imminent research goals in this area is to design novel external field patterns and control strategies with an aim for a scalable assembly. In this dissertation, MHz AC electric fields are used to generate reconfigurable and multi-dimensional fields and to accomplish three goals: 1) understanding equilibrium phase behaviors under multi-dimensional external fields, 2) controlling assembly of defect-free colloidal crystal with optimal strategy, and 3) scale up the assembly control to hierarchical colloid structures. Equilibrium behavior of particles under external field is critical in understanding phase transition and nonuniform distribution of colloidal systems; it is also important practically in investigating novel control mechanisms. Equilibrium particle concentration profile can be derived by considering the interaction between particles and field and by balancing the interactions with osmotic pressure due to inhomogeneous particle concentration. Equation of states for effective hard disks can be used to relate osmotic pressure with particle concentration, so that we can derive a general relationship between the external energy landscape and particle concentration distribution. Based on the theory, we successfully predicted local and global phase transitions as well as two-dimensional particle distribution under external fields. Our findings also provide foundations for the following dynamic control problems. For the second goal, we rely on morphing electric fields and energy landscapes to control the self-assembly of particles into defect-free crystals with circular morphology. We first observed that morphology changes in response to applied electric fields enhance the diffusion of grain boundaries and formation of perfect crystals. We derived an optimal feedback control strategy based on the initial observation and a reinforcement learning study. We showed that the assembly of perfect crystal is most efficient when the applied anisotropic field is aligned with grain boundary orientation. The control strategy achieves 100% yield of perfect crystals within an order of magnitude shorter time compared to precedent works. We also demonstrated the scalability of our approach in assembly of larger colloidal systems. Finally, we extend our knowledge in design an assembly strategy for hierarchical structures. Our specific goal is to achieve periodic colloidal crystals with perfect structure and circular morphology. We design an electrode array with independently activated poles, which can dynamically generate multiple DC and MHz AC electric fields. Through computer simulations, we showed a control process includes coarse partitioning particles into separate clusters, equalizing cluster size by particle redistribution, removing grain boundaries in all clusters, and restoring circular morphologies for the periodic structures. We demonstrated the scalability of the control to various cluster sizes. We also discussed potential applications of electrode array and field mediate assembly in other scenarios

Photovoltage Detection of Edge Magnetoplasmon Oscillations and Giant Magnetoplasmon Resonances in A Two-Dimensional Hole System

In our high mobility p-type AlGaAs/GaAs two-dimensional hole samples, we originally observe the B-periodic oscillation induced by microwave (MW) in photovoltage (PV) measurements. In the frequency range of our measurements (5 - 40 GHz), the period ({\Delta}B) is inversely proportional to the microwave frequency (f). The distinct oscillations come from the edge magnetoplasmon (EMP) in the high quality heavy hole system. In our hole sample with a very large effective mass, the observation of the EMP oscillations is in neither the low frequency limit nor the high frequency limit, and the damping of the EMP oscillations is very weak under high magnetic fields. Simultaneously, we observe the giant plasmon resonance signals in our measurements on the shallow two-dimensional hole system (2DHS)

The energy and exergy analysis on the performance of counter-flow heat and mass exchanger for M-Cycle indirect evaporative cooling

© 2018 Serbian Society of Heat Transfer Engineers. The dew point Indirect Evaporative Cooling (IEC) achieved through Maisotsenko cycle (M-Cycle) is a complicated thermodynamic process. For further understanding of the heat and mass transfer occurred in a dew point indirect evaporative air cooler with M-Cycle counter-flow configuration, the paper presents a novel mathematical model that combined the law of energy conservation and the principle of the thermodynamic theory. The model was used to carry out the parametric study of the dew point air cooler under various inlet air temperature and relative humidity. Through the combined analysis of energy and exergy of the target IEC system, it is found that both the inlet air temperature and relative humidity have an important effect on the thermal performance and thermodynamic performance of the heat and mass exchanger. The high temperature environment helps to get better thermal performance and thermodynamic performance. It has been showed in this paper that the best thermal performance does not correspond to the best thermodynamic performance. Thus, the energy and exergy analysis should be implemented simultaneously for the optimization of the process to get the best thermal performance at permissible level of thermodynamic cost

The energy and exergy analysis of counter-flow regenerative evaporative cooler

© 2018 Serbian Society of Heat Transfer Engineers. Recently the regenerative evaporative cooler (REC) has drawn great attention from researchers because it can cool the intake air below the wet-bulb temperature and approaching its dew point temperature. For further understanding of the heat and mass transfer occurred in a counter-flow REC, a novel mathematical model is developed based on the law of energy conservation and the principle of the thermodynamic theory. The proposed mathematical model is validated against experimental data from literature. The parametric study is performed to investigate the performance of the REC under different operating and geometrical conditions. It is found that the exergy destruction and exergy efficiency ratio of the REC are strongly influenced by the intake air velocity, the working to intake air ratio and channel gap, followed by the channel length. The working to intake air ratio choosing from 0.3 to 0.4 is appropriate in order to achieve better thermal performance with permissible level of thermodynamic cost. Moreover, the results obtained in this paper reveal that the best thermal performance does not correspond to the best thermodynamic performance. Thus, both the first and second law of thermodynamics should be considered for a comprehensive analysis