Roadmap on measurement technologies for next generation structural health monitoring systems

Structural health monitoring (SHM) is the automation of the condition assessment process of an engineered system. When applied to geometrically large components or structures, such as those found in civil and aerospace infrastructure and systems, a critical challenge is in designing the sensing solution that could yield actionable information. This is a difficult task to conduct cost-effectively, because of the large surfaces under consideration and the localized nature of typical defects and damages. There have been significant research efforts in empowering conventional measurement technologies for applications to SHM in order to improve performance of the condition assessment process. Yet, the field implementation of these SHM solutions is still in its infancy, attributable to various economic and technical challenges. The objective of this Roadmap publication is to discuss modern measurement technologies that were developed for SHM purposes, along with their associated challenges and opportunities, and to provide a path to research and development efforts that could yield impactful field applications. The Roadmap is organized into four sections: distributed embedded sensing systems, distributed surface sensing systems, multifunctional materials, and remote sensing. Recognizing that many measurement technologies may overlap between sections, we define distributed sensing solutions as those that involve or imply the utilization of numbers of sensors geometrically organized within (embedded) or over (surface) the monitored component or system. Multi-functional materials are sensing solutions that combine multiple capabilities, for example those also serving structural functions. Remote sensing are solutions that are contactless, for example cell phones, drones, and satellites. It also includes the notion of remotely controlled robots

Analysis of the Viability of Tourism and Future Development Strategy in the Qinghai-Tibet Plateau Region

The purpose of the article is to evaluate the current situation of the tourism industry in the Qinghai-Tibet Plateau and discuss further developing strategies. The main research approach is through the SWOT method, and the main data resources are secondary data from relative articles and organizations. In general, through the SWOT analysis, the strength of the Qinghai-Tibet Plateau regions in to develop tourism industry includes unique natural and socio-cultural environments, high-quality infrastructure, and government support; the weakness includes the lack of professional tourism operators and innovative and diverse tourism products; the opportunities including the increasing number of middle classes in China and possible involvement of the local community in the future; the threats mainly from the negative impacts from tourism to the unique natural and socio-cultural local environments. Future developing strategies are focused on 4 perspectives: being sustainable, having business viability, increasing the involvement of the local community, and building infrastructure in a more sustainable approach

A SOLUTE PEAK ASSOCIATED WITH THE GRAIN BOUNDARIES OF IRON CONTAINING A SMALL AMOUNT OF CARBON

Some investigations of the effect of interstitial solute additions on the grain boundary peak were made in iron. At the higher temperature side of the iron grain boundary peak, a "carbon solute peak" appeared for iron containing 0.0002 wt% and 0.0005 wt% carbon. The activation energy for grain boundary relaxation in pure iron is 49±3 kcal/mol find that for the "carbon solute peak" is equal to 85±4 kcal/mol. The solvent peak disappeared as the amount of carbon increased up to 0.0027 wt%. Therefore, it seems easy to explain the results given by Miles and Leak that no solute peak appeared together with the solvent peak in iron containing carbon and there was an abrupt change on the curve of variation of activation energy for grain boundary damping of iron with carbon content. The mechanism of solute peak was discussed

Assessing the Ecological Carrying Capacity Based on Revised Three-Dimensional Ecological Footprint Model in Inner Mongolia, China

Under the concept of green development, accurately mapping ecological carrying capacity to effectively evaluate regional sustainability has already become an important issue in China. This study introduced ecological carrying capacity intensity (ECintensity) based on the revised three-dimensional ecological footprint (3DEF) model to describe the temporal–spatial patterns of three-dimensional ecological carrying capacity (EC3D) in Inner Mongolia in 2010–2016 and to explore factors affecting socioeconomic sustainable development. The results showed that ecological footprint size (EFsize) differed between cities/leagues but changed little during the study period. Ecological footprint depth (EFdepth) far exceeded the original value of 1.00. Ecological carrying capacity (EC) varied in cities/leagues, while ECintensity increased slowly with stronger potential for regional development. Three-dimensional ecological deficits (ED3D) of cities/leagues were divided into five categories: Hohhot, Hulunbuir and Banyannur were in larger ecological surplus; Hinggan was in slight surplus; Baotou, Chifeng, Tongliao, Ulanqab, Xilin Gol and Erdos were in slight deficit; Wuhai was in stronger deficit; and Alxa was in severely intense deficit. Woodland of cities/leagues was continuously in slight ecological surplus, while cropland and grassland had crucial impacts on deficit. There was a significant positive linear correlation between gross domestic product (GDP) and footprint, while a negative correlation was seen with deficit. These results would help coordinate resource utilization and industrial structure adjustment in Inner Mongolia

Design and Synthesis of Immunoadjuvant QS-21 Analogs and Their Biological Evaluation

A series of novel immunoadjuvant QS-21 analogs were synthesized, and their effects on the in vitro hemolysis of red blood cells were evaluated using QS-21 as a control and hemolytic properties as an index. Our results show that all the QS-21 analogs had lower hemolytic effects than QS-21, and their concentrations exhibited a certain quantitative effect relationship with the hemolysis rate. Notably, saponin compounds L1–L8 produced minimal hemolysis and showed lower hemolytic effects, warranting further investigation

INTERNAL FRICTION ASSOCIATED WITH DOMAIN WALLS AND FERROELASTIC PHASE TRANSITION IN LNPP

Two internal friction peaks (50 - 100kHz) have been measured in LNPP near its transition temperature. The peak at TC=141°C is associated with the ferroelastic transition where the elastic constant C55 vanishes and the peak at a lower temperature is attributed to the motion of domain walls. The variation of domain walls and its relation to Q-1 were obtained by in situ measurements. The mechanisms of the peaks are discussed

Niche Evolution of China’s Provincial Social–Economic–Natural Complex Ecosystems, 2005–2015

The ecological niche of a complex regional ecosystem reflects the fit of various human activities and the advantages and disadvantages of the environment in the region. This study examined China’s comprehensive niches of the compound social–economic–natural ecological system during the “11th Five-Year” and “12th Five-Year” periods using a Full Permutation Polygon Synthetic Indicator method. The results showed that before the 11th Five-Year period, the levels of comprehensive niches in the country were generally low, and, by the end of the 11th Five-Year period, the comprehensive niche levels in Beijing, Tianjin, and the eastern coastal regions each exceeded 0.40. During the 12th Five-Year period, after the ecological civilization construction plans were implemented, the average national comprehensive ecological level reached 0.57, the comprehensive ecological niche levels in eastern coastal areas reached more than 0.84, those in southern regions and some developed middle and western regions were greater than 0.72, and, in central regions, the levels were between 0.50–0.70. This shows that the concept of compound sustainable natural–societal–economic ecosystem development was incorporated into planning and used to guide local policies and assessment criteria for regional development. This paper compares the advantages and disadvantages of regional development plans through time, and can be used to promote coordinated and sustainable regional development

The Impact of Greenspace on Thermal Comfort in a Residential Quarter of Beijing, China

With the process of urbanization, a large number of residential quarters, which is the main dwelling form in the urban area of Beijing, have been developed in last three decades to accommodate the rising population. In the context of intensification of urban heat island (UHI), the potential degradation of the thermal environment of residential quarters can give rise to a variety of problems affecting inhabitants’ health. This paper reports the results of a numerical study of the thermal conditions of a residential quarter on a typical summertime day under four greening modification scenarios, characterized by different leaf area density (LAD) profiles. The modelling results demonstrated that vegetation could evidently reduce near-surface air temperature, with the combination of grass and mature trees achieving as much as 1.5 °C of air temperature decrease compared with the non-green scenario. Vegetation can also lead to smaller air temperature fluctuations, which contribute to a more stable microclimate. The Universal Thermal Climate Index (UTCI) was then calculated to represent the variation of thermal environment of the study area. While grass is helpful in improving outdoor thermal comfort, trees are more effective in reducing the duration and expansion of suffering from severe heat stress. The results of this study showed that proper maintenance of vegetation, especially trees, is significant to improving the outdoor thermal environment in the summer season. In consideration of the deficiency of the current code in the management of greenspace in residential areas, we hope the results reported here will help promote the improvement of the code and related regulations for greenspace management

A Novel Hydrophilic, Antibacterial Chitosan-Based Coating Prepared by Ultrasonic Atomization Assisted LbL Assembly Technique

To explore the potential applicability of chitosan (CTS), we prepared aldehyde chitosan (CTS-CHO) with chitosan and sodium periodate via oxidation reaction and then a chitosan-based hydrophilic and antibacterial coating on the surface of poly (lactic acid) (PLA) film was developed and characterized. The oxidation degree was determined by Elemental analyser to be 12.53%, and a Fourier transform infrared spectroscopy was used to characterize the structure of CTS-CHO. It was evident that CTS-CHO is a biocompatible coating biomaterial with more than 80% cell viability obtained through the Live/Dead staining assay and the alamarBlue assay. The hydrophilic and antibacterial CTS-CHO coating on the PLA surface was prepared by ultrasonic atomization assisted LbL assembly technique due to Schiff’s base reaction within and between layers. The CTS-CHO coating had better hydrophilicity and transparency, a more definite industrialization potential, and higher antibacterial activity at experimental concentrations than the CTS coating. All of the results demonstrated that the ultrasonic atomization-assisted LbL assembly CTS-CHO coating is a promising alternative for improving hydrophilicity and antibacterial activity on the PLA surface. The functional groups of CTS-CHO could react with active components with amino groups via dynamic Schiff’s base reaction and provide the opportunity to create a drug releasing surface for biomedical applications