Standard Design Research Articles

EVALUATING WASTEWATER TREATMENT EFFICIENCY OF MEDICAL CENTERS IN BINH DUONG PROVINCE

This paper presents a comprehensive analysis of the wastewater management system implemented at a medical center located within the Bau Bang Industrial Park in Binh Duong province, Vietnam. With a staff of 166 and 60 beds, the facility operates in accordance with TCVN 4470:2012 General Hospital design standards, serving a diverse range of water demands including domestic, medical, and auxiliary requirements. The wastewater management system is meticulously designed to handle both rainwater and wastewater separately. Rainwater is efficiently collected through surface and roof drainage networks, while domestic and medical wastewater undergo discrete collection processes. The medical center's wastewater treatment facility, operating at a capacity of 100 m³/day, employs a multistage treatment process to ensure compliance with stringent regulatory standards (QCVN 28:2010/BTNMT, column B, K = 1). This process includes preliminary treatment, anaerobic and aerobic biological treatment, membrane filtration, and disinfection. The facility consistently meets quality parameters outlined in QCVN 28:2010/BTNMT, exhibiting effective removal rates for organic pollutants, suspended solids, ammonia, phosphates, and pathogens. Furthermore, the medical center demonstrates commendable environmental stewardship through its stormwater drainage infrastructure, which integrates seamlessly with the local drainage network, safeguarding against environmental contamination. Overall, the wastewater management practices at the medical center exemplify best practices in environmental management within the healthcare sector. This study provides valuable insights into the design, implementation, and performance evaluation of wastewater treatment systems in industrial settings, contributing to the global discourse on sustainable wastewater management practices.

Establishment of a Flow-Through System for the Macrophyte Growth Inhibition Test (OECD 239) Including Photosynthetic Activity Measurement to Determine Early Effects.

Maintaining constant exposure concentrations during ecotoxicological studies while testing rapidly degradable substances is a challenge. To achieve stable concentrations during exposure, flow-through systems are used. To assess the impact of substances on higher aquatic plants, the 14-day macrophyte water-sediment Myriophyllum spicatum growth inhibition test (Organisation for Economic Co-operation and Development [OECD, 2014a] test guideline 239) only includes a static or a semistatic test design. The main aim of our study was to investigate the applicability of a flow-through system for M. spicatum. The standard OECD test design was miniaturized, and a flow-through system with spill-over was developed to achieve stable exposure concentrations of a rapidly degrading substance. The main endpoints were total shoot length and fresh and dry weight. Photosynthetic activity was used as an endpoint for the identification of early effects using the noninvasive Image-Producing Pulse Amplitude Modulation (IMAGING-PAM) procedure. Atorvastatin (AV; fast degrading) and bentazone (BT; photosynthesis inhibitor) were used as model substances to observe differences of the effect concentration depending on the test design. At higher exposure levels of AV, stronger necrosis combined with lower effect concentrations was observed in the flow-through test compared with the semistatic test, indicating the applicability of the flow-through test for evaluating degradable substances. The test with BT demonstrated a concentration-dependent decrease in the photosynthetic yield (Y(II)) from day 3 onward even before macroscopically visible changes occurred. Our results show that the flow-through system in the macrophyte growth inhibition test (OECD test guideline 239; 2014a) is a suitable alternative when one is testing rapidly degradable substances such as AV. In addition, we showed that photosynthetic yield can serve as a supplementary endpoint, when one is testing substances with photosynthesis inhibition as a mode of action. Environ Toxicol Chem 2024;00:1-12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Addressing localized thermal comfort needs of the human body through advanced personal thermal management garments design and evaluation

Personal thermal management clothing has garnered significant attention in recent years for offering innovative solutions to address extreme environments. By examining the “human-clothing-environment” system, we have analyzed the contribution and developmental trajectory of personal thermal management clothing, considering the diverse human needs and application environments. Local variations in human physiology necessitate localized thermal comfort solutions provided by personal thermal management clothing. Despite advancements, many Personal thermal management garments still encounter challenges such as bulky size, heavy weight, intricate donning process, subpar performance, limited temperature control, and low durability. Furthermore, aspects like comfort, ergonomics, and aesthetics, tailored to specific usage scenarios, have often been overlooked. Enhancing the standardized design and evaluation processes for personal thermal management clothing items is crucial to better cater to individual preferences and usage demands, offering recommendations for development to align with individual requirements, enhance effectiveness, and promote energy conservation.

Predicting mechanical properties of sustainable green concrete using novel machine learning: Stacking and gene expression programming

Abstract Using rice husk ash (RHA) as a cement substitute in concrete production has potential benefits, including cement consumption and mitigating environmental effects. The feasibility of RHA on concrete strength was investigated in this research by predicting the split tensile strength (SPT) and flexural strength (FS) of RHA concrete (RHAC). The study used machine learning (ML) methods such as ensemble stacking and gene expression programming (GEP). The stacking model was improved using base learner configurations ML models, such as, random forest (RF), support vector regression, and gradient boosting regression. The proposed models were validated by statistical tests and external validation criteria. Moreover, the effect of input parameters was investigated using Shapley adaptive exPlanations (SHAP) for RF and parametric analysis for GEP-based models. The analysis revealed that the stacking ensemble integrates base learner predictions and demonstrated superior performance, with R values greater than 0.98 and 0.96. Mean absolute error and root mean square error values for both SPT and FS were 0.23, 0.3, 0.5, and 0.7 MPA, respectively. The SHAP analysis demonstrated water, cement, superplasticizer, and age as influential parameters for the RHAC strength. Furthermore, the SPT and FS of RHAC can be predicted with an acceptable error using the GEP expressions in the standard design procedure.

Accuracy of vestibular schwannoma segmentation using deep learning models - a systematic review & meta-analysis.

Following 2020 PRISMA guidelines, a search across four databases was conducted. Inclusion criteria focused on articles using DL for VS MR image segmentation. The primary metric was the Dice score, supplemented by relative volume error (RVE) and average symmetric surface distance (ASSD). The search process identified 752 articles, leading to 11 studies for meta-analysis. A QUADAS- 2 analysis revealed varying biases. The overall Dice score for 56 models was 0.89 (CI: 0.88-0.90), with high heterogeneity (I2 = 95.9%). Subgroup analyses based on DL architecture, MRI inputs, and testing set sizes revealed performance variations. 2.5D DL networks demonstrated comparable efficacy to 3D networks. Imaging input analyses highlighted the superiority of contrast-enhanced T1-weighted imaging and mixed MRI inputs. This study fills a gap in systematic review in the automated segmentation of VS using DL techniques. Despite promising results, limitations include publication bias and high heterogeneity. Future research should focus on standardized designs, larger testing sets, and addressing biases for more reliable results. DL have promising efficacy in VS diagnosis, however further validation and standardization is needed. In conclusion, this meta-analysis provides comprehensive review into the current landscape of automated VS segmentation using DL. The high Dice score indicates promising agreement in segmentation, yet challenges like bias and heterogeneity must be addressed in the future research.

Meeting the challenge of mitigating Li-ion battery fires for aviation

The aviation industry faces a pressing challenge in reducing its environmental footprint, especially with the projected growth in global passenger traffic. Electrification and more-electric aircraft, particularly through Lithium-ion Battery (LiB) systems, offers a promising pathway to reduce emissions but introduces significant safety concerns, particularly regarding thermal runaway (TR) events. This prospective paper examines the unique challenges posed by aviation environments for developing safe LiB systems. It discusses multifaceted mitigation approaches, integrating fire containment structures with advanced thermal management and fire protection technologies. Various cooling technologies and fire suppression agents are explored for their effectiveness in extinguishing LiB fires and mitigating thermal runaway propagation. Integrated LiB suppression systems are proposed to combine fire containment, suppression, and thermal management functionalities for achieving the demanding specific energy density levels that will be required. Scaling safe LiB pack solutions for commercial aviation requires coordinated efforts among regulators, original equipment manufacturers (OEMs), engineers, and researchers to establish standardized design criteria, develop validated modeling tools, and establish rigorous certification testing requirements. In conclusion, addressing the safety concerns of large LiB packs in aircraft applications requires a holistic, integrated approach. This paper provides insights into current research, identifies key challenges, and outlines future directions for advancing LiB safety in aviation.

Tips for Accelerating BOIN Design.

During discussions at the Data Science Roundtable meeting in Japan, there were instances where the adoption of the BOIN design was declined, attributed to the extension of study duration and increased sample size in comparison to the 3 + 3 design. We introduce an accelerated BOIN design aimed at completing a clinical phase I trial at a pace comparable to the 3 + 3 design. Additionally, we introduce how we could have applied the BOIN design within our company, which predominantly utilized the 3 + 3 design for most of its clinical oncology dose escalation trials. The accelerated BOIN design is adaptable by using efficiently designated stopping criterion for the existing BOIN framework. Our approach is to terminate the dose escalation study if the number of evaluable patients treated at the current dose reaches 6 and the decision is to stay at the current dose for the next cohort of patients. In addition, for lower dosage levels, considering a cohort size smaller than 3 may be feasible when there are no safety concerns from non-clinical studies. We demonstrate the accelerated BOIN design using a case study and subsequently evaluate the performance of our proposed design through a simulation study. In the simulation study, the average difference in the percentage of correct MTD selection between the accelerated BOIN design and the standard BOIN design was - 2.43%, the average study duration and the average sample size of the accelerated BOIN design was reduced by 14.8 months and 9.22, respectively, compared with the standard BOIN design.

Computational design of residential units’ floor layout: A heuristic algorithm

Computer-aided intelligent design can improve the quality and efficiency of residential building design. However, the design conditions are diverse, and numerous combinations of spatial elements exist. We propose a heuristic algorithm—the combined Monte Carlo tree search (MCTS) and particle swarm optimization (PSO) algorithm (PSO-MCTS)—for the automated design of residential floor layouts. The MCTS algorithm deals with discrete variables (room locations). It considers architectural design experience and design standards during node pruning to compress the search space and simplify the computation. The PSO algorithm deals with continuous variables (room sizes) and accelerates the computing speed due to parallel processing. The PSO-MCTS algorithm achieves a good balance between computational efficiency and accuracy. It is suitable for various design conditions and requirements. The input parameters include the daylight façade, boundary scope, entrance location, room type and size, and relationships with adjacent rooms. The PSO-MCTS provides 100 %, 80 %, and 75 % better results than heuristic algorithms, designs by architects, and a state-of-the-art deep learning model, respectively.

Advancing Circular Buildings: A Review of Building Strategies for AEC Stakeholders

The uptake of a circular economy (CE) in the building sector is challenging, primarily due to the complexity associated with the design process and the dynamic interaction among architects, engineers, and construction (AEC) stakeholders. The standard and typical design process and construction methods raise concerns about building life cycles. Buildings should not only fulfill current needs, but one also needs to consider how they will function in the future and throughout their lifetime. To address these complexities, early planning is required to guide designers in holistically applying systems thinking to deliver CE outcomes. This paper outlines a critical review of CE implementation in buildings, with a proposed trifecta of approaches that significantly contribute to the development of circular buildings (CBs). The findings outline a proposed visualized framework with a conceptual formula that integrates CE design strategies to simplify and enhance AEC stakeholders’ perception of the circularity sequence in buildings. By strategically integrating loop-based strategies with the value retention process (VRP) and design for X (DFX) strategies, along with efficient assessment tools and technologies, it becomes feasible to embrace a CE during the design phase. The outcome of this review informs AEC stakeholders to systematically and strategically integrate the critical dimensions of a CE throughout the building life cycle, striking a balance between environmental concern, economic value, and future needs.

Risk assessment of general FPSO supply system based on hybrid fuzzy fault tree and Bayesian network

One of the major risks to the operation of a FPSO (Floating, Production, Storage and Offloading) is collision of supply vessels. Experiences have shown that collisons of supply vessel take place frequently, although the consequences are limited. The offshore oil&gas industry has established relevant design standards and operational procedures, which are proven to be effective in reducing this risk. As the risk assessment becomes increasingly applied, there is a need to quantify the likelihood of supply vessel collisions especially duing the early design/project stage when historical incident data does not exist. This paper proposees a method for estimating the likelihood of supply vessel collision based on fault tree analysis (FTA), Bayesian network (BN), hybrid theory and fuzzy theory. In liew of using historicval data, this method combines the fuzzy logic with expert heuristics to determine the basic events(BEs). The triangular fuzzy membership functions and a hybrid theory were adopted to define factors that lack data or had no data in the events. To account for the imprecise information of human error, a scheme is devised to use the fuzzy fault probability(FFP) based on the hybrid theory, or a hybrid fuzzy fault tree analysis (HFFT). The algorithm transforms the FT into a BN with a conditional probability table (CPT). This new method was demonstrated in an example of a FPSO, and the results were has been validated through case studies and accident reports. A sensitivity analysis was also conducted to illustrate key parameters.

Robust sparse recovery with sparse Bernoulli matrices via expanders

Sparse binary matrices are of great interest in the field of sparse recovery, nonnegative compressed sensing, statistics in networks, and theoretical computer science. This class of matrices makes it possible to perform signal recovery with lower storage costs and faster decoding algorithms. In particular, Bernoulli (p) matrices formed by independent identically distributed (i.i.d.) Bernoulli (p) random variables are of practical relevance in the context of noise-blind recovery in nonnegative compressed sensing.In this work, we investigate the robust nullspace property of Bernoulli (p) matrices. Previous results in the literature establish that such matrices can accurately recover n-dimensional s-sparse vectors with m=O(sc(p)log⁡ens) measurements, where c(p)≤p is a constant dependent only on the parameter p. These results suggest that in the sparse regime, as p approaches zero, the (sparse) Bernoulli (p) matrix requires significantly more measurements than the minimal necessary, as achieved by standard isotropic subgaussian designs. However, we show that this is not the case.Our main result characterizes, for a wide range of sparsity levels s, the smallest p for which sparse recovery can be achieved with the minimal number of measurements. We also provide matching lower bounds to establish the optimality of our results and explore connections with the theory of invertibility of discrete random matrices and integer compressed sensing.

The Performance of a Circular Excavation Supported by a Prefabricated Recyclable Structure in a Full-Scale Test

Excavations for underground structures, such as working shafts, underground grain silos, and parking garages, are characterized by uniformity, consistent dimensions, large quantities, and strict timelines. Prefabricated recyclable supporting structures (PRSS) are gaining attention over traditional retaining structures due to their standardized design, efficient construction, and reusability, which suit such excavations better. To validate their performance, full-scale tests are conducted to analyze the deformation and stress characteristics of PRSS. The results show that the average maximum lateral displacement of supporting pile is 0.07% of the excavation depth (He), roughly half that of steel plate. Differences in ground surface settlement behind steel plates and the supporting piles are not as significant as those in their lateral displacements. While the displacement of the supporting piles is insufficient to induce soil movement into the active limit state on the non-excavation side, the circular excavation’s arching effect reduces the earth pressure on this side of the supporting piles below the active earth pressure limit. Furthermore, the earth pressure acting on the steel plates is lower than that acting on the supporting piles, suggesting the presence of a soil arching effect between two adjacent piles. These findings offer valuable insights for guiding the construction of PRSS.

Effect of Fashion E-Commerce User Experience on Customer Retention in Ghana

Purpose: The aim of the study was to analyze the effect of fashion e-commerce user experience on customer retention in Ghana. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Research indicates that positive user experiences, characterized by intuitive website navigation, efficient mobile interfaces, and responsive customer service, greatly enhance customer retention rates. Users who encounter seamless transactions, personalized recommendations, and reliable delivery services are more likely to return and engage with fashion e-commerce platforms repeatedly. Unique Contribution to Theory, Practice and Policy: Theory of planned behavior (TPB), self-determination theory (SDT) & expectation-confirmation theory (ECT) may be used to anchor future studies on effect of fashion e-commerce user experience on customer retention in Ghana. Practically, fashion e-commerce platforms should invest in user-friendly website design and navigation to enhance the overall shopping experience. This includes simplifying the checkout process, ensuring mobile compatibility, and improving site speed. From a policy perspective, e-commerce regulations should include guidelines for user experience best practices. This could involve setting standards for website accessibility, data protection, and user interface design to ensure a positive online shopping experience.

Exposure proximal immune correlates analysis.

Immune response decays over time, and vaccine-induced protection often wanes. Understanding how vaccine efficacy changes over time is critical to guiding the development and application of vaccines in preventing infectious diseases. The objective of this article is to develop statistical methods that assess the effect of decaying immune responses on the risk of disease and on vaccine efficacy, within the context of Cox regression with sparse sampling of immune responses, in a baseline-naive population. We aim to further disentangle the various aspects of the time-varying vaccine effect, whether direct on disease or mediated through immune responses. Based on time-to-event data from a vaccine efficacy trial and sparse sampling of longitudinal immune responses, we propose a weighted estimated induced likelihood approach that models the longitudinal immune response trajectory and the time to event separately. This approach assesses the effects of the decaying immune response, the peak immune response, and/or the waning vaccine effect on the risk of disease. The proposed method is applicable not only to standard randomized trial designs but also to augmented vaccine trial designs that re-vaccinate uninfected placebo recipients at the end of the standard trial period. We conducted simulation studies to evaluate the performance of our method and applied the method to analyze immune correlates from a phase III SARS-CoV-2 vaccine trial.

Comparative review and novel design possibilities on solar-driven absorption LiBr-H2O refrigeration system

Solar energy is a promising source of energy because of its potential due to the reduction usage of non-renewable energy. As the demand for cooling increases, solar-powered cooling technologies are becoming increasingly promising. Among the different solar cooling systems, LiBr-H2O absorption chillers are commonly used due to their advantages over NH3-H2O systems. Multiple cycle LiBr-H2O chillers can be powered by easily available flat-plate, evacuated tubular or parabolic solar collectors. This paper reviews Theoretical Principles-Based Analysis and Simulations of solar LiBr-H2O absorption cooling systems, performance comparison of each types and introduces new design options related to auxiliary energy systems and cooling mode cycle. The paper also summarizes other main types of solar absorption cooling systems, including double-effect, half-effect, triple effect and give updates of new technology design of hybrid effect. The choice of water-cooled or air-cooled absorption refrigeration depends on the local climate and water availability. Recent advances have made air-cooled absorption refrigeration a viable option, with comparable COP to water-cooled systems and lower maintenance requirements. Additionally, geothermal heat rejection with low pressure drops can further reduce energy consumption. Solar-powered double-effect absorption cooling systems are recommended for buildings with high cooling loads, while half-effect are suitable for air-cooled solar absorption cooling systems in hot and dry regions with limited water. This paper is specifically intended for those interested in developing solar-driven LiBr-H2O absorption chillers, emphasizing the importance of establishing standardized design guidelines to specific regions and climates in order to promote and expand the usage of solar cooling systems.

A Systematic Review of Mathematics Vocabulary Interventions for Students With or At-Risk for Mathematics Difficulty

This systematic review synthesizes the effects of mathematics vocabulary interventions on the mathematics outcomes of students with mathematics difficulty (MD) in Grades K through 12. We evaluated methodological rigor using three indicators: research design, implementation fidelity, and instruction in the counterfactual. Six peer-reviewed studies and three unpublished dissertations between 1990 and 2022 met inclusion criteria. Results showed mathematics vocabulary interventions improved students’ vocabulary knowledge, particularly when instruction was explicit with multiple opportunities to practice. Findings were less conclusive on whether improved mathematics vocabulary knowledge led to improved performance on related mathematics content. Results suggest mathematics vocabulary intervention is beneficial for higher-level mathematics reasoning, such as word-problem solving. The seven group design studies received an M rating of at least acceptable for methodological rigor, and one of two single-case studies met What Works Clearinghouse design standards without reservations. We highlight promising instructional practices implemented across studies that resulted in improved vocabulary outcomes.

The Evolution and Performance of Cold-Formed Steel Built-Up Battened Columns

The cold-formed steel (CFS) built-up battened column represents a transformative and innovative solution in the construction industry due to its versatility, cost-effectiveness, and superior strength-to-weight ratio. In design consideration, chord spacing and batten plates influence the structural performance and stability of the column. The emphasis lies in the design flexibility of built-up battened columns, in which the composite action of several chord members connected by batten plates can enhance axial compressive strength. The batten plate plays a crucial role in preventing buckling and increasing the stability of the column while distributing the load evenly. The batten plates need to be properly designed to ensure stability and reduce buckling failure in the built-up battened column. However, implementing CFS built-up battened columns presents several challenges, including design complexity, connection design, and limited standards and guidelines.

Investigation of the Overall Damage Assessment Method Used for Unmanned Aerial Vehicles Subjected to Blast Waves

With the aim of investigating the assessment methodology for the overall damage effects on an unmanned aerial vehicle (UAV) subjected to a blast wave, the failure criteria for the typical UAV was formulated through an analysis of the structural strength design standards. Specifically, the shear force associated with wing failure can serve as a critical parameter for assessing the overall damage inflicted on the UAV by blast waves. According to the design load criterion of the aircraft, the shear force value corresponding to the overall failure of the typical UAV was calculated. Numerical simulations were conducted to investigate the mechanical response of UAV structures under blast wave loading generated by a 500 g explosive. Combining the critical shear force values obtained from theoretical calculations with the numerical simulation results, two distances between the explosives and the UAV that could produce different damage effects were estimated, namely 1 m and 2.5 m. Subsequently, static explosion experiments with equivalent explosive charges were performed, revealing different damage effects on a typical UAV at two specific distances. The numerical simulation results were highly consistent with the experimental observations, further validating the scientific and rational basis for using shear force as a primary parameter in assessing overall structural damage to fixed-wing UAVs.

New orders of 2k factorial designs generated by simulated annealing adapted to optimality criteria

Excessive changes in factor levels can lead to a high cost in practice and hinder the conduction of experiments, in addition to adding a higher computational cost and loss of the orthogonality property, resulting in numerical problems in estimating the parameters of a model. The sequential specification of experimental points, seen as treatments in a 2k factorial design, results in a high-order bias in some factors, which is caused by the accumulation of −1 or +1 signals. This study aimed to propose new designs generated by the simulated annealing technique, respecting the main A-optimal and D-optimal optimality criteria as random execution orders that minimize the order bias. This approach allowed the generation of 24 and 25 factorials, which were compared to the designs in standard order. The simulated annealing technique is a viable method to generate optimal designs with the same efficiency as the usual designs to obtain A-optimal and D-optimal designs with new execution orders, which minimize the effect of order bias relative to standard order designs. Regarding efficiency, the generated designs were precise in the variance of model parameter estimates, similar to the original designs.

Zero-Gap Liquid Alkaline Water Electrolyzers: Challenges in Benchmarking and Directions for Development

Green hydrogen is expected to play a central role in the replacement of fossil energy sources, especially in difficult to decarbonize sectors of the economy. Currently, low temperature methods of electrolysis are the only commercially realized sources of green hydrogen. Liquid alkaline water electrolysis (LAWE) is the most widely utilized method of electrolysis, with a 100-year history of use. Given this lengthy history one could be forgiven for assuming that there is little development left. However, standard LAWE materials and cell designs do not achieve the production, efficiencies, and durability necessary to meet the anticipated demand for green hydrogen.To spur development in this neglected area of hydrogen production, the US Department of Energy, Hydrogen and Fuel Cell Technology Office (DOE-HFTO) added LAWE to its Hydrogen from Next-generation Electrolyzers of Water (H2NEW) Consortium. One of the main tasks for this part of the consortium is to benchmark and validate materials and cell components for LAWE. This includes the development of lab-scale cell hardware and test protocols that can be widely disseminated in the research community. The result of this work will be the development of the methods and materials necessary to achieve robust and reproducible datasets for the improvement of catalysts, separators, cell architecture and operation.We will present the status of the benchmarking effort. This will include a description and explanation of a lab-scale LAWE test station, electrolyte handling, and hydrogen safety. The requirements for the safe operation of an electolyzer using high concentration alkaline electrolytes differs significantly from more typical proton exchange, or anion exchange membrane systems. We will also discuss common sources of error that can significantly influence cell performance and result in poor reproducibility. Acknowledgement:This research is supported by the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office through the Hydrogen from Next-generation Electrolyzers of Water (H2NEW) consortium.