Noncontact sensing systems and autonomous decision-making for early-age concrete

Early-age cracking and spalling in concrete pavements reduces slab capacity, joint load transfer, ride quality, and its long-term performance. These premature distresses lead to increased maintenance costs for sealing, patching, and grinding. Proper timing of sawcutting and curing are two construction activities that can minimize early-age distress development. In order to better time sawcutting and curing activities, an improved method to spatially monitor the setting time of concrete is required. Likewise, rapid evaluation of the joint quality after sawing is also necessary to provide feedback to adjust the timing. While previous methods for sawcutting and curing are experiential and subjective, this research aims to develop contactless sensing and computer vision techniques to significantly improve the timing of certain early-age concrete construction activity decisions through quantitative indicators. A non-contact, ultrasonic testing system (UTS) to monitor concrete set time has been developed by monitoring the evolution of leaky Rayleigh (LR-wave) wave signals over time and space (surface of the concrete). The non-contact UTS integrates a 50 kHz non-contact ultrasonic transmitter and an array of five microelectromechanical systems (MEMS) sensors as non-contact receivers. The UTS technique was first implemented in the laboratory at incident angles of 12^° for mortar mixtures in order to determine the final setting times. The UTS technique was also applied at different incident angles (12^° to 60^° ) on a mortar mixture to evaluate its influence of the angle on the UTS measurement. The final setting times for mortars were consistent with the ASTM C403 penetration resistance standard when an incident angle of 12^° was used. Additionally, this UTS was successfully field validated on three concrete pavement test sections in Illinois that had different casting times during the day. Final setting times in the field greatly varied (287 to 210 minutes) given the higher ambient temperatures and surrounding concrete mass. In order to improve decision-making on sawcut timing, the final set times measured by the UTS were linked with the earliest time to initiate sawcutting within an acceptable level of raveling. A computer vision-based (CV) process was developed that employed multiple joint images, 2D segmentation for joint raveling/spalling extraction, 3D point cloud reconstruction and meshing of the joint damage, and a 3D damage quantification analysis for assessing the joint damage. The proposed CV-based joint damage analysis quantified joint damage through two newly defined indices: (i) raveling damage index (RDI) for raveling and (ii) joint damage index (JDI) for spalling. The proposed CV-based method had an accuracy of 76% with an error of 10%. With this CV-based process, it was determined that RDI of 3% or less is an acceptable quality level for contraction joints in the field. A one-sided multi-sensor ultrasonic array device with a support vector machine algorithm was developed that detects the existence of a concealed, vertical crack beneath a notched contraction joint. This algorithm supports the field assessment of the effectiveness of sawcut timing, sawcut depth, and whether premature slab cracking was related to poor sawing procedures. The multi-sensor ultrasonic array device generated and received ultrasonic shear waves (S-wave) across the inspected joint. The acquired time domain signals were used to calculate normalized transmission energy (NTE) across the joint. The NTE algorithm defined the ratio of the energy of diffracted and reflected S-waves received behind the joint with respect to the energy of direct, diffracted, and reflected S-waves received in front of the joint. Laboratory results demonstrated that the NTE technique could successfully identify the existence or non-existence of a crack beneath the sawcut. Finally, the NTE technique coupled with a 2D decision boundary equation was field validated on 152 concrete pavement contraction joints from multiple projects with similar slab thicknesses and sawcut notch depths in Illinois and Iowa. Finally, the non-contact UTS was coupled with a 2D wavefield analysis to rapidly evaluate the effectiveness, spatially and with time, of curing methods through monitoring of the near-surface damage in hydrating paste at early-ages. The new technique monitored the energy of the LR-waves signal over time with the non-contact UTS and then, analyzed the frequency-wave number (f-k) domain to characterize the quantity of near-surface damage in the cement paste specimens. An ultrasonic surface damage index (USDI) was defined from the f-k wavefield domain based on the ratio of the non-propagating and forwarding LR-wave energy. The non-contact sensing and 2D wavefield analysis easily distinguished the differences in surface damage between the different curing methods (no curing surface, the plastic sheet cover cure, and the wax-based curing). Surfaces with low surface damage had negligible non-propagating wave energy, which was seen in the wax-based curing specimens and the unexposed bottom surfaces of all cast specimens

DETERMINATION OF THE PLANT LOCATIONS FOR ENSURING SOME ENVIRONMENTAL CRITERIA

Joint Research on Environmental Science and Technology for the Eart

DETERMINATION OF THE PLANT LOCATIONS FOR ENSURING SOME ENVIRONMENTAL CRITERIA

Joint Research on Environmental Science and Technology for the Eart

Environment Impacts and Composition - Biotoxic Activity in Natural Hydrocarbon Raw Materials & Processed Products

The paper aims to figure out What are environment impacts and composition - biotoxic activity in natural hydrocarbon raw materials and processed products. By using descriptive method for primary model, synthesis methods and process analysis and analysis of difficulties and discussion, The study of this problem point that, to assess the environmental impact of hydrocarbons on the biosphere, an accurate knowledge of the physical properties and chemical composition of oil and gas. Numerous tragic examples of accidents, such as those associated with a leak hydrogen sulfide gases. Hydrogen sulfide, due to its higher density relative to air settles in the lowlands of the relief, accumulating in calm weather in concentrations up to lethal. This leads to the death of animals and the death of people. The latter could be avoid by going to elevated windward areas, i.e., knowing the physical properties of this toxic gas

Two-dimensional optimization problem of plant location

In this paper, the following matters are presented: the adjoint problem of the two-dimensional matter propagation problem; the algorithm for determination of a domain in which a plant can be located so that the values of the pollution-level reflecting functional does not exceed a given value at considered sensitive areas; application of this algorithm for numerical experiments to a typical problem

Application of monte carlo simulation method to estimate the reliability of design problem of the bored pile according to limited state

This paper applies Monte Carlo simulation method to estimate the reliability of bored pile for designing problem at “Tax Office of Phu Nhuan District”. Surveyed random variables are physico-mechanical properties of soil and loads are assumed that they follow the normal distribution. Limit state functions developed from design requirements of Ultimate limit state (ULS) and Serviceability limit state (SLS). Results show that the probability of failure is 0 and the reliability index of ULS is 9.493 and of SLS is 37.076 when examining coefficient of variation of soil and loads of 10%. The paper also considers the safety level when evaluating different coefficients of variation in the range of 10 ~30%. The authors suggest applying the reliability method to design calculation for other construction to help the engineers have a visual perspective, increase safety and avoid wastage

A Novel Modeling Framework for Computationally Efficient and Accurate Real‐Time Ensemble Flood Forecasting With Uncertainty Quantification

A novel modeling framework that simultaneously improves accuracy, predictability, and computational efficiency is presented. It embraces the benefits of three modeling techniques integrated together for the first time: surrogate modeling, parameter inference, and data assimilation. The use of polynomial chaos expansion (PCE) surrogates significantly decreases computational time. Parameter inference allows for model faster convergence, reduced uncertainty, and superior accuracy of simulated results. Ensemble Kalman filters assimilate errors that occur during forecasting. To examine the applicability and effectiveness of the integrated framework, we developed 18 approaches according to how surrogate models are constructed, what type of parameter distributions are used as model inputs, and whether model parameters are updated during the data assimilation procedure. We conclude that (1) PCE must be built over various forcing and flow conditions, and in contrast to previous studies, it does not need to be rebuilt at each time step; (2) model parameter specification that relies on constrained, posterior information of parameters (so‐called Selected specification) can significantly improve forecasting performance and reduce uncertainty bounds compared to Random specification using prior information of parameters; and (3) no substantial differences in results exist between single and dual ensemble Kalman filters, but the latter better simulates flood peaks. The use of PCE effectively compensates for the computational load added by the parameter inference and data assimilation (up to ~80 times faster). Therefore, the presented approach contributes to a shift in modeling paradigm arguing that complex, high‐fidelity hydrologic and hydraulic models should be increasingly adopted for real‐time and ensemble flood forecasting.Key PointsA surrogate model must be built over various forcing and flow conditions and it does not need to be rebuilt at each time stepModel parameter specification for data assimilation can significantly improve forecasting performance and reduce uncertainty boundsNo substantial differences in results exists between single and dual EnKFs, but the latter better simulates flood peaksPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154302/1/wrcr24506_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154302/2/wrcr24506.pd

Competencies of the Team of Department Head at Higher Education Institutions in Vietnam in The Context of the Industrial Revolution 4.0

This study aims to investigate the Competencies of the team of department head at higher education institutions in Vietnam to implement higher education development in the context of the industrial revolution 4.0. The authors conducted a Delphi study with 15 experts in educational management in Vietnam to gather their expert views on the competencies of the team of department head at higher education institutions. A total of 24 components of competency related to 4 fields (professional expertise, scientific research, subject management and leadership, social activities and international cooperation) were strongly emphasized by experts. The competence of the team of department head is proposed based on the ideas of a group of experts and the results need to be tested, completed and confirmed by follow-up work. Besides, in this study, we have not determined the level of achievement of each competence as well as developed assessment tools. The specific competencies of the team of department head can be considered as a foundation to contribute to the development of higher education in the context of the industrial revolution 4.0. We know that competence does not exist independently; in stead of, they should be considered in the specific context of teaching, university, culture and society. This study is one of the studies related to the competence contextualization of the team of department head at higher education institutions in the Vietnamese context

Collaboration Between Social Workers and Educational Forces in Schools: Advantages, Objectives, Content, and Form

Cooperation between social workers and educational forces in high schools is viewed as a two-way cooperative effort to assist learners needing intervention. Intervention, emergency support for teachers or students needing intervention or assistance; Organize events to promote student development, community integration, and assistance for teachers and parents in need. The evaluation criteria for the cooperation between social workers and educational forces are based on four coordination components. Includes four scales evaluating the advantages, objectives, contents, and form of cooperation between high school social work personnel and educational agencies. A review of the cooperation between social work personnel and educational forces in high schools is gaining interest, although no research has been conducted on this topic. According to research findings, coordination between social work personnel and educational forces in high schools has been formed, albeit to a low and inconsistent degree across activities. The institution must perfect the organizational structure of its operations, management, and social work divisions. Furthermore, when coordinating with educational forces, social work personnel must emphasize the benefits of cooperation with educational forces. In addition, social workers must be adaptable between forms and activities according to the conditions and nature of their work.Ho Chi Minh City University CS.2021.19.4

Seed Health and Quality of Rice Seeds Produced by Farmer and Growing in Cho Moi District, An Giang Province, Vietnam

This study was conducted at Laboratory in An Giang University; the varieties examined were collected from farmer households in 2018 – they were varieties that the farmer stored for the next crop (Winter-Spring) from Autumn-Winter crop in Cho Moi district, An Giang Province, Vietnam. The research evaluated the quality of seed rice, which is provided and planted by the farmer. As a result, this study showed that almost all of the varieties of seed rice from farmer households indicated the ratio of filled-grain, the germination, and the determination of seedling healthy, which are lower than certified variation. Besides, the samples of seed rice from farmer household have more infected fungal; especially the samples with higher in a filled-grain ratio is less infected by fungi, there were 12 types of seed borne-fungi in rice varieties from the farmer (in Cho Moi district), included: Alternaria padwickii, Rhizoctonia solani, Aspergillus oryzae, Bipolaris oryzae, Cercospora janseana, Curvularia lunata, Fusarium moniliforme, Pyricularia oryzae, Sarocladium oryzae, Tilletia barclayana, Fusarium graminearum, and Ustilaginoidea viren