Optimal Design of Renewable Energy Systems in Low/Zero Energy Buildings

Low energy building and zero energy building have attracted increasing attention in both academic and professional fields following the ambitions of many governments in reducing building energy consumption and carbon emission. This paper presents an investigation on the optimal design of renewable energy systems in two types of buildings: Low Energy Buildings and Zero Energy Buildings. The first zero energy building in Hong Kong, namely Hong Kong Zero Carbon Building (ZCB), is taken as a reference building in this study. The TRNSYS building model is used to generate the annual cooling load profile of the building. Simplified models are developed to simulate the building energy systems including the air-conditioning systems and the renewable energy systems in Matlab while the building annual cooling load profile is taken as the input. GA (Genetic Algorithm) method and NSGA-? (Non-dominated Sorting Genetic Algorithm) approach are implemented for single objective optimization and multi-objectives optimization respectively in Matlab. Three most important design parameters, i.e., sizes of PV, wind turbine and bio-diesel generator, are chosen as the variables to be optimized. Three objectives (total cost, CO2 emission and grid stress factor) are adopted in the multi-objective optimization. They also form the objective function in the case of single objective optimization. The performances of buildings with different combinations of renewable system sizes are compared and evaluated. The effects of the two types of buildings on the design decisions of renewable energy system sizes are studied and compared. Furthermore, the uses of single objective and multi-objective optimization methods and their advantages/disadvantages in system optimization applications are discussed

AIMS Online Testing System, an interactive web-based testing system for medical school courses

This paper will describe my development of Aims Online Testing System, an interactive web-based testing mechanism which was established as a pilot project as well as a learning and evaluation tool, using Microsoft SQL Server 7.0, ColdFusion, JavaScript and Visual Basic for the School of Medicine, UNC Chapel Hill. An explanation of the process followed to create this product, information of the software used, description of the final design, analysis of risks and constrains as well as envision of the future work constitute the main body of the paper. At the end, user guides are appended to indicate how an online exam is implemented. As a pilot project, although the final success will not be known until it used in classroom in the future, this technical report has immediate importance because it documents the creation and implementation of the web-based testing system

1,2-Dimeth­oxy-3-[(E)-2-nitro­ethen­yl]benzene

The title compound, C10H11NO4, was synthesized via condensation of 2,3-dimeth­oxy­benzaldehyde with nitro­methane using microwave irradiation without solvent. The H atoms of the –CH=CH– group are in a trans configuration. The dihedral angle between the mean planes of the benzene ring and the nitro­alkenyl group is 23.90 (6)°

Definition and Design of Zero Energy Buildings

The wide application of renewable energy system (RES) in buildings combined with numerous financial incentives on RES paves the way for future zero energy buildings (ZEB). Although the definition of ZEB still lacks a national building code and international standards, the number of ZEB projects is still increasing worldwide which seems to be the pioneer ZEB buildings. However, due to the intermittency of the renewable resources, various uncertain parameters, and dynamic electricity price from the grid, how to select the renewable energy system for buildings is one of the challenges and therefore becomes an extensive concern for both researchers and designers. In addition, questions like how to achieve the target of zero energy for different types of buildings, should the building be designed as an independent ZEB or a group of buildings to be a ZEB cluster, and how to make building owners actively involved in installing enough RES for the building are still on the air. This chapter will present a comprehensive view on several key issues related with ZEB, that is, definition, evaluation criteria, design method, and uncertainty analysis, and the penalty cost scheme is also proposed for consideration as one policy to assist the promotion of ZEB

Thermal conductivity, structure and mechanical properties of konjac glucomannan/starch based aerogel strengthened by wheat straw

This study presents the preparation and property characterization of a konjac glucomannan (KGM)/starch based aerogel as a thermal insulation material. Wheat straw powders (a kind of agricultural waste) and starch are used to enhance aerogel physical properties such as mechanical strength and pore size distribution. Aerogel samples were made using environmentally friendly sol–gel and freeze drying methods. Results show that starch addition could strengthen the mechanical strength of aerogel significantly, and wheat straw addition could decrease aerogel pore size due to its special micron-cavity structure, with appropriate gelatin addition as the stabilizer. The aerogel formula was optimized to achieve lowest thermal conductivity and good thermal stability. Within the experimental range, aerogel with the optimized formula had a thermal conductivity 0.04641 Wm−1 K−1, a compression modulus 67.5 kPa and an elasticity 0.27. The results demonstrate the high potential of KGM/starch based aerogels enhanced with wheat straw for application in thermal insulation

Comparative antiseizure medications of adjunctive treatment for children with drug-resistant focal-onset seizures: A systematic review and network meta-analysis

Purpose: In this study, we intended to compare and rank the efficacy and acceptability of antiseizure medications (ASMs) for adjunctive treatment of children with drug-resistant focal-onset seizures.Method: We conducted a computerized search of PubMed, EMBASE, Cochrane Library, Web of Science, and Google Scholar to identify eligible randomized controlled trials (RCTs) published before 31 May 2022. We included studies evaluating the efficacy and tolerability of antiseizure medications for children with drug-resistant focal-onset seizures. The efficacy and safety were reported in terms of responder and dropout rate along with serious adverse events, the outcomes were ranked with the surface under the cumulative ranking curve (SUCRA).Results: A total of 14 studies (16 trials) with 2,464 patients were included, involving 10 active antiseizure medications. For the primary endpoint of at least 50% reduction in focal-onset seizures, the surface under the cumulative ranking curve ranking suggested that lamotrigine and levetiracetam were more effective as compared with other antiseizure medications; moreover, levetiracetam had the highest probability of rank first for achieving seizure freedom. Concerning tolerability, oxcarbazepine and eslicarbazepine acetate were associated with higher dropout rates relative to other antiseizure medications and placebo, and topiramate was associated with higher occurrence of side effects. No significant differences were found between active antiseizure medications concerning dropout for side effects.Conclusion: According to the surface under the cumulative ranking curve ranking, lamotrigine, levetiracetam, and oxcarbazepine were more efficacious than other active antiseizure medications in terms of responder rate. Concerning tolerability, oxcarbazepine was more likely to lead to dropout and topiramate was associated with higher occurrence of side effects

Micro pore characteristics of Luohe aquifer sandstone in Binchang Mining Area typical roof water hazard mines

The mining of Huanglong Coalfield faces a serious threat from roof sandstone water disaster of the extremely thick Luohe Formation. A laboratory study on the microscopic pore characteristics of the sandstone of the Luohe Formation in the Gaojiapu Coal Mine, Binchang Mining Area were carried out using various methods. XRD diffraction, casting thin sections, and scanning electron microscopy were combined to study the pore types of the sandstone particles. Overburden porosimeter was used to illustrate the variation characteristics of porosity and permeability under different confining pressures. High-pressure mercury injection and nuclear magnetic resonance techniques were used to characterize the pore-throat radius of the sandstone core, and X-ray three-dimensional CT scanning was used to quantitatively characterize sandstone pores larger than 9 μm. The results show that, ①the sandstone particles of medium-grained sandstone are larger, and the pore types are mainly residual intergranular pores with a small amount of intergranular dissolved pores, while the particles of fine-grained sandstone are smaller, and the intergranular pores are mostly filled with clay minerals, secondary dissolution intergranular pores, and a smaller degree of pore development.; ②The pore throat radius of large pores in medium-grained sandstone ranges from 0.61 to 4.94 μm, with a cumulative distribution frequency of 48%, while in fine-grained sandstone, the pore-throat radius ranges from 0.188 to 0.683 um, with a cumulative distribution frequency of 47%, indicating that medium-grained sandstone has larger pore-throat radius, which are more conducive to groundwater storage and migration.; ③CT scanning shows that the average surface porosity of medium-grained sandstone is 7.081%, and that of fine grained sandstone is 2.032%. The highly developed macropores (equivalent pore diameter > 180 μm) and micropores contribute to a higher surface porosity. Combined with a larger pore throat radius, the medium-grained sandstone presents a higher permeability. The microscopic pore characteristics of the two types of sandstone are consistent with the on-site evaluation result of the water yield propertyof the corresponding aquifer. The research findings can provide a basic reference for the prevention and control of water disasters from the sandstone roof of the Luohe Formation