RESUMO
In light of the suboptimal resource efficiency persisting in current demolition waste management (DWM) practices caused by inattentive and profit-driven decision-making due to the lack of tailored stringent legislation, monetary incentives, and benchmarking frameworks, this study aims to facilitate sustainability-oriented decision-making at the demolition planning stage. A practical Building Information Modelling (BIM)-based visual DWM planning system is designed, wherein the system seamlessly accommodates inventory analysis and Multi-Criteria Decision-Aiding (MCDA) algorithms into various interconnected modules. Moreover, this research proposes bespoke algorithms and colour coding schemes to quantify and visualise the recycling value of building components for augmenting the visual guidance of sustainable building design and selective demolition planning. Furthermore, a pilot case study demonstrates the system's applicability in a real-world demolition project. The findings unveil that improving the recycling rate substantially offsets carbon emissions and demolition waste disposal expenditures. The increment in beneficial impacts outweighs the additional energy consumption and costs for implementing sustainable DWM strategies based on the predefined geographical settings. This BIM-based system reforms the conventional demolition planning and DWM decision-making workflow by tackling technical barriers concerning data richness, interoperability, and result interpretation. It equips the users with intuitive visual design guidance and parallel scenario analysis when crafting sustainability-oriented DWM schemes. In summary, this research contributes to familiarising industry practitioners with sustainable DWM schematic design and circular economy principles. Moreover, it prompts the development of customised BIM libraries as repositories for updating and capitalising on DWM-related information that can be adapted to different regional contexts.
Assuntos
Indústria da Construção , Eliminação de Resíduos , Gerenciamento de Resíduos , Materiais de Construção , Reciclagem , Resíduos IndustriaisRESUMO
Addressing the sustainability issues arising from construction and demolition waste management (DWM) has gained little traction due to the lack of incentives, stringent regulations, and systematic guidance. This study aims to empower systematic decision-making concerning DWM alternative selection by developing a sustainability assessment framework by coupling a modified Delphi method with the multicriteria decision analysis technique. First, the study identifies a comprehensive inventory of indicators across three dimensions of sustainability in the context of DWM. Next, the study combines a modified Delphi method with the analytic hierarchy process to validate and prioritize the selected sustainability indicators. For the first time, insights regarding the DWM sustainability indicators from China's construction industry practitioners' perspectives are elicited using a mixed method comprising online semistructured interviews and two rounds of questionnaire surveys. Experts participating in the research are mostly based in Guangzhou and Shenzhen, where local governments exhaust all efforts in promoting carbon-neutral and sustainable development. The findings reveal that eight sustainability indicators were regarded as the determinants for the sustainability performance of DWM, with the global warming potential (32%), energy efficiency (16.1%) and land use (13.5%) receiving the highest preference scores (weights) based on the experts' judgment. Notably, the economic factors like the total cost (6.54%) appeared not highly prioritized by the local experts as typically did in the previous studies from developing countries.
Assuntos
Indústria da Construção , Gerenciamento de Resíduos , Processo de Hierarquia Analítica , ChinaRESUMO
Ultraperformance convergence chromatography is an environmentally friendly analytical technique for dramatically reducing the use of organic solvents compared to conventional chromatographic methods. In this study, a rapid and sensitive ultraperformance convergence chromatography method was firstly established for quantification of thymol and carvacrol, two positional isomers of a major bioactive in the volatile oil of Thymi herba, the dried leaves and flowers of Thymus mongolicus or Thymus przewalskii, known in China as "Dijiao." Using a TrefoilTM CEL1 column, thymol and carvacrol were separated in less than 2.5 min and resolution was enhanced. The method was validated with respect to precision, accuracy, and linearity according to the National Medical Products Administration guidelines. The optimized method exhibited good linear correlation (r = 0.9998-0.9999), excellent precision (relative standard deviations (RSDs) < 1.50%), and acceptable recoveries (87.29-102.89%). The limits of detection for thymol and carvacrol were 1.31 and 1.57 ng/L, respectively, while their corresponding limits of quantification were 2.63 and 3.14 ng/L. Finally, the quantities of the two compounds present in 16 T. mongolicus and four T. przewalskii samples were successfully evaluated by employing the developed method. It is hoped that the results of this study will serve as a guideline for the quality control of Thymi herba.
Assuntos
Cromatografia/métodos , Cimenos/análise , Timol/análise , Thymus (Planta)/química , China , Cromatografia/instrumentação , Cimenos/química , Cimenos/isolamento & purificação , Flores/química , Isomerismo , Óleos Voláteis/química , Folhas de Planta/química , Timol/química , Timol/isolamento & purificaçãoRESUMO
Because of the complex and fine structure, visualization of the heart still remains a challenging task, which makes it an active research topic. In this paper, we present a visualization system for medical data, which takes advantage of the recent graphics processing unit (GPU) and can provide real-time cardiac visualization. This work focuses on investigating the anatomical structure visualization of the human heart, which is fundamental to the cardiac visualization, medical training and diagnosis assistance. Several state-of-the-art cardiac visualization methods are integrated into the proposed system and a task specified visualization method is proposed. In addition, auxiliary tools are provided to generate user specified visualization results. The contributions of our work lie in two-fold: for doctors and medical staff, the system can provide task specified visualization with interactive visualization tools; for researchers, the proposed platform can serve as a baseline for comparing different rendering methods and can easily incorporate new rendering methods. Experimental results show that the proposed system can provide favorable cardiac visualization results in terms of both effectiveness and efficiency.
Assuntos
Coração/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Gráficos por Computador , HumanosRESUMO
Coastal lagoon is critical habitat for human and provides a wide range of ecosystem services. These vital habitats are now threatened by waste discharge and eutrophication. Previous studies suggest that the pollution mitigation of coastal lagoon relies on the water exchange with open sea, and the role of microbial processes inside the lagoon is overlooked. This study takes the Pinqing Lagoon which is the largest coastal lagoon in Chinese mainland as example. The distribution of nutrients, microbial activity of nitrogen removal and community structure of denitrifying bacteria in sediment are analyzed. The results showed that the nutrient in sediment represented by DIN (1.65-12.78 mg kg-1), TOM (0.59-8.72 %) and TN (0.14-1.93 mg g-1) are at high levels and are enriched at the terrestrial impacted zone (TZ). The microbial nitrogen removal is active at 0.27-19.76 µmol N kg-1 h-1 in sediment and denitrification is the dominate pathway taking 51.44-98.71 % of total N removal. The composition of the denitrifying microbial community in marine impacted zone (MZ) is close to that of ocean and estuary, but differs considerably with those of TZ and transition zone (TM). The denitrification activity is mainly controlled by salinity and pH, and the denitrifying bacterial community composition related to the nutrient parameters of TN, TOM, etc. Our study suggested that the distribution of nutrients, microbial activity of nitrogen removal and community structure in Lagoon are the combined effects of terrestrial input and exchange with open sea. The microbial processes play important role in the nitrogen removal of coastal lagoon.
Assuntos
Desnitrificação , Ecossistema , Humanos , Nitrogênio/análise , Salinidade , China , Concentração de Íons de HidrogênioRESUMO
Extracting entities and relations from the unstructured text has attracted increasing attention in recent years. The existing work has achieved considerable results, yet it is difficult to solve entity overlap and exposure bias. To address cascading errors, exposure bias, and entity overlap in existing entity relation extraction approaches, we propose a joint entity relation extraction model (SMHS) based on a span-level multi-head selection mechanism, transforming entity relation extraction into a span-level multi-head selection problem. Our model uses span-tagger and span-embedding to construct span semantic vectors, utilizes LSTM and multi-head self-attention mechanism for span feature extraction, multi-head selection mechanism for span-level relation decoding, and introduces span classification task for multi-task learning to decode out the relation triad in a single-stage. Experiments on the classic English dataset NYT and the publicly available Chinese relationship extraction dataset DuIE 2.0 show that this method achieves better results than the baseline method, which verifies the effectiveness of this method. Source code and data are published here(https://github.com/Beno-waxgourd/NLP.git).