Design Methodology Research Articles

Phosphate removal from aqueous solutions using reversal mode electrocoagulation with iron and aluminum electrodes: RSM optimization and ANN modeling

Abstract Phosphate pollution significantly contributes to eutrophication and the degradation of aquatic ecosystems. The removal of phosphate from wastewater before discharging into the environment is essential for the sustainability of the ecosystem. This work focuses on using a polarity reversal mode electrocoagulation (PRM-EC) system integrated with iron (Fe) and aluminum (Al) electrodes to remove phosphate from wastewater. The conditions for the removal process were optimized using response surface methodology (RSM). Central composite design (CCD) was used to design the experiment and numerical optimization was utilized to find the optimal conditions. The phosphate removal efficiency could reach 93.12% at a current density of 40 A m−2, time of 30 min, pH of 6.4, and electrode distance of 10.5 mm. The energy consumption was about 0.4 kW m−3. The artificial neural network (ANN) modeling showed that the current density was the most influencing factor, followed by time, pH, and electrode distance. The mechanism underlying the PRM-EC process encompassed electrode dissolution, floc formation, phosphate adsorption, and precipitation. The findings in the work show that PRM-EC is an environmentally friendly and effective solution for phosphate removal.

The Chinese version of the Nursing Student Academic Resilience Inventory: A validity and reliability study

AimTo translate and adapt the Nursing Student Academic Resilience Inventory (NSARI) into Chinese and assess its validity and reliability among Chinese nursing students. BackgroundNursing students frequently encounter stress during their clinical education and academic resilience is an important skill to help students withstand stress. The NSARI is a valid and reliable tool for assessing the level of academic resilience of nursing students during clinical practice. Currently, there is no valid and reliable measurement tool to assess academic resilience for nursing students in China. DesignA descriptive, methodological and cross-sectional design was used. MethodThis study was conducted on 600 nursing students in Northeast China. A socio-demographic form, the Chinese version of the NSARI and the nurse resilience scale were used for data collection between May to November 2023. The exploratory factor analysis and confirmatory factor analysis samples comprised 300 students, respectively, to test the structural validity of the inventory. In addition, internal consistency and invariance analyses were conducted to assess the reliability of the inventory. ResultsThe Chinese version of NSARI comprises 24 items separated into six dimensions. Exploratory factor analysis extracted six factors, with a cumulative variance contribution rate of 71.908%. Confirmatory factor analysis showed a satisfactory fit. Cronbach’s alpha coefficient for the internal consistency of the total inventory was 0.939 with a test-retest stability reliability value of 0.957. ConclusionThe Chinese version of NSARI is a valid and reliable measurement tool for assessing the level of academic resilience of nursing students during clinical placement.

Redefining Hospital Accessibility: A Service Design Framework for Inclusive Healthcare

Abstract In the framework of becoming a carbon neutral city by 2030, Bologna faces challenges related to enhancing the quality and accessibility of its built environment to improve the quality of life and well-being of its residents. The IRCCS Azienda Ospedaliero-Universitaria Sant’Orsola Polyclinic is a key agent of change within this initiative. The hospital has initiated a comprehensive renovation project aligned with its commitment to the United Nations Sustainable Development Goals (SDGs), particularly SDG 3, which addresses Good Health and Well-being, and SDG 10, which addresses Reduce Inequalities. To address these goals, the hospital has engaged a research team from the University of Bologna to apply Service Design methodologies. The research aims to reshape accessibility and user experience systematically and sustainably, adhering to the principles of Design for All. The study maps diverse user groups, analyses circulation paths, and identifies physical and procedural barriers affecting vulnerable individuals, especially those with disabilities. The research introduces a novel approach by developing a comprehensive strategy rather than isolated solutions, focusing on interconnected accessibility services across pavilions. Dedicated hubs within each pavilion facilitate resource and support device exchange, improving users’ experiences. A pilot project, initially targeting wheelchair accessibility hubs, employs innovative technologies to enhance independent tool usage and monitor distribution and maintenance efficiently. The project is now entering a testing phase, during which the solution will be refined based on user feedback.

Environmental impact assessment of a direct methanol fuel cell and strategic mitigation guidelines

Direct methanol fuel cells (DMFCs) are gaining attention as a viable technology for portable and remote applications due to the benefits of methanol as fuel. However, the environmental implications of this technology have not been thoroughly evaluated. This study aims to conduct a comprehensive assessment of the environmental impact of a DMFC throughout its entire life cycle, and based on the findings, propose guidelines for minimizing the impact. To eliminate any potential biases, a two-step design methodology is applied. The first step involves obtaining the optimal preliminary design, for which a genetic algorithm is implemented. The second step is to conduct the environmental impact study on that optimal configuration. As a study case, a DMFC for a highly demanding application, such as an unmanned aerial vehicle, is selected, using green methanol as fuel. The results reveal that extraction and production stage has the greatest effect on the environment (74.1%), compared to use (25.8%) and transport stages (0.1%). Among the components of the stack, the catalysts have the most significant environmental footprint, 93.3% of the total impact of the stack during the extraction and production stage, while bipolar plates represent only 5.9%, despite comprising 86% of the stack’s mass.

Enhancing skimmed milk powder functionalities through multicriteria optimization of outlet drying air temperature and spraying air pressure

This study investigated the effects of spraying air pressure and outlet air temperature on the physicochemical and functional properties of skimmed milk powder. Experimental design methodology showed that higher outlet air temperatures improved dry matter content, gelation ability, and flowability, but strengthened colour, moisture sensitivity, and favoured protein denaturation. Spraying air pressure primarily influenced particle size, affecting powder rheological properties and colour. This study highlights the importance of controlling drying parameters to optimize powder properties. The use of a genetic evolutionary algorithm in the optimization process allowed the simultaneous improvement of several functionalities of skimmed milk powder. The findings of this study can contribute to the development of enhanced powders with tailored properties for specific industrial applications.

Universal Design Methodology for Multiline Hybrid HVDC Circuit Breakers Based on Generalized Circuit Topology

Universal Design Methodology for Multiline Hybrid HVDC Circuit Breakers Based on Generalized Circuit Topology

Inkjet‐printed capacitively loaded Marchand baluns with enhanced fractional bandwidths

AbstractA comprehensive design methodology for the realization of ultra‐wideband and highly miniaturized capacitively loaded Marchand baluns (MBs), suitable for integration into balanced antenna systems is presented. A design technique to maximize the fractional bandwidth (FBW) for a given manufacturing process is demonstrated for the first time. Furthermore, a novel MB integration scheme using broadside‐coupled lines and 3D vertically integrated capacitors in a two‐material inkjet printing process is uniquely proposed. The concept has been experimentally validated within the S and C bands. It exhibits a footprint of 0.128 × 0.098 λg2, centre frequency of 4.4 GHz, and FBW of 121%. Its power loss, phase imbalance and amplitude imbalance were measured between 0.8 and 2.2 dB, 3 ± 2°, and 0.4 ± 0.4 dB, respectively.

Spacecraft Control Design Methodology Based on Reinforcement Learning Methods

Spacecraft Control Design Methodology Based on Reinforcement Learning Methods

Evaluation of compression behaviour of 316L SS Gyroid and Diamond structures using SLM process – Experimental programme under static and dynamic compression loadings

The relative comparison in terms of energy absorption efficiency for a set of 4 structures made of various Triply Periodic Minimal Surfaces (TPMS) topologies is experimentally investigated. These TPMS structures are printed by Selective Laser Melting AM process using 316L SS. The study is carried out in consideration of the effect of parameters such as relative density, compressive loading directions and loading rates, number of unit cells for Diamond and Gyroids TPMS both declined for Sheet and Skeletal topologies. The objective is to quantify their structural responses in terms of apparent stress and strain, dynamic enhancement and Specific Energy Absorbed (SEA) and to evaluate their structural integrity in terms of collapse stability. The results reveal that the Sheet pattern of TPMS structures with its constant wall thickness and uniform geometry exhibits better energy absorption capabilities than the Skeletal pattern. The Diamond family shows greater interest rather than the Gyroid family only in the case of the Sheet pattern. The increase in relative density from 20 to 30% is characterized by improved manufacturing quality, an increase in energy absorption capacity and more homogeneous progressive deformations during compression. On the whole, the set of TPMS geometries exhibits energy absorption capacities prior to those of other conventional cellular materials currently used for impact engineering applications. Finally, in a first approach, an original design methodology using charts can be developed to establish a link between the energy absorption capabilities and the design geometric parameters of TPMS structures.

Scaled-up production and recovery of lipopeptide biosurfactant and its application for washing petroleum-contaminated drill cuttings

A simple and efficient fermentation strategy using chitosan-immobilized Bacillus subtilis GY19 was developed for large-scale lipopeptide production from waste glycerol and palm oil. When a fed-batch fermentation approach was employed, excessive foaming was minimized, while lipopeptide production was greater than that of conventional batch fermentation. When a 700L stirred tank fermenter with a 400L working volume was used, a lipopeptide concentration and yield of 7.55g/L and 0.190g/g of substrate, respectively, were achieved. The pilot-scale recovery process involved sequential bacterial cell removal via centrifugation, elimination of impurities through acidification of the cell-free broth, and partial purification and concentration of the lipopeptides via ultrafiltration. A 5kDa stabilized cellulose-based membrane maintained a constant permeate flux and resulted in 67.2% lipopeptide recovery. The concentrated lipopeptide retentate contained 16.8g/L lipopeptides and a surface tension of 28.82 mN/m. A biobased washing agent for the treatment of petroleum-contaminated drill cuttings was later formulated with the retentate and various vegetable oil-based surfactants via the simplex−lattice mixture design methodology. The mixture of 1% retentate and 4% fatty alcohol ethoxylate 5EO presented the greatest removal efficiency of 83.2% for drill cuttings containing 15% (w/w) total petroleum hydrocarbons. The formulation also mobilized petroleum hydrocarbons into a distinct free oil layer, which would be easy to separate and subsequently recycle. These findings demonstrate the scalability of the lipopeptide production and recovery process, while the biobased washing agent offers an environmentally friendly approach for petroleum remediation.

Optimizing aggregate grading and residual mortar coefficient in low-cement concrete by using crushed coal mine waste rock as base layers for low-traffic roads

In the context of depleting natural resources and environmental challenges posed by large-scale extraction and use of natural aggregates, this study investigates the use of crushed coal mine waste rock (CCMWR) as a sustainable alternative for low-cement concrete in the base layers of low-traffic roads. The primary goal is to optimize the aggregate grading and the residual mortar coefficient (RMC) to enhance the performance and durability of low-cement concrete. Utilizing the I-optimal design methodology and curve of Fuller for particle size distribution, this research evaluates the mechanical properties, workability, and environmental impact of incorporating CCMWR in low-cement concrete. The findings demonstrate that with the appropriate optimization, CCMWR can effectively replace natural aggregates, significantly reducing the ecological footprint and providing an effective solution for sustainable road construction. This research holds substantial engineering application significance by offering an innovative approach to classify and reuse waste from the coal mining industry while addressing the urgent need for sustainable infrastructure development.

A Full-Iteration Optimal Design Methodology of CLLC Converter With Minimized RMS Current

A Full-Iteration Optimal Design Methodology of <i>CLLC</i> Converter With Minimized RMS Current

Enhancing Agricultural Extension Programs: A Practical Guide to Designing and Implementing Randomized Controlled Trials

Evidence-based practices in agricultural extension programs must be guided by precise evaluation strategies and reliable data. Methods like randomized controlled trials (RCTs) are vital for assessing specific program interventions. However, not all studies use experimental designs, and their quality varies, as noted in a 2010 World Bank study. RCTs, known for providing robust impact assessments, involve complex steps and are applied in various fields. This guide focuses specifically on RCTs used for agricultural extensions; a topic covered less often than clinical trials. More precisely, this guide provides (1) definitions and key steps for RCTs, (2) a simplified RCTs study design methodology, (3) an exploration of challenges and mitigation, and (4) a summary of relevant RCTs studies in extensions. This guide is formulated to enhance the present understanding of RCTs and elaborate on the ways to use them in their application in agricultural research. Furthermore, the goal here is to make sure that our policies and methods are presented with solid evidence. This approach is meant to encourage the implementation of agricultural practices that are not only more effective but also sustainable.

Multistage Charge Pump Design Methodology for Zero-Crossing-Based Amplifiers

Multistage Charge Pump Design Methodology for Zero-Crossing-Based Amplifiers

Putting “First Peoples” First: Participatory Design of a Digital Storytelling System for Inuvialuit Communities

ABSTRACTThis poster presents a community‐focused participatory design methodology as a basis for developing a digital storytelling system for the Inuvialuit Settlement Region in Canada's Western Arctic. It provides an overview of the various stages of digital storytelling system prototype design informed by an Inuvialuit elder's storytelling gathering and a community experience open house. Among the prototype redesign ideas are empathy maps we are using to allow us to connect stories with designs and community needs in mind.

An ultrathin ultralight electromagnetic absorber based on shortcut glass-coated amorphous magnetic Fiber/Salisbury-like screen

A structural design methodology is proposed for an ultrathin, ultralight, and absorption-adjustable electromagnetic absorber. The proposed absorber (SFSL) consists of an absorbing layer with shortcut glass-coated amorphous magnetic fiber and a substrate layer with transmitting material. This absorber features a Salisbury-like screen structure and incorporates multiple loss mechanisms. By investigating the influence of fiber distribution, length, content, and substrate layer thickness on absorption performance, it has been determined that the weight per square meter and thickness of a single-layer SFSL can be lowered within 50 g/m2 and 1.5 mm respectively. Furthermore, the absorption intensity and bandwidth can be adjusted by manipulating these parameters. The SFSL exhibits resonant behavior similar to that of a metamaterial absorber; however, SFSL with randomly distributed fibers demonstrates broader and stronger absorption characteristics in the frequency range from 2 to18 GHz. Additionally, the thicknesses of the substrate layer and surface covering affect the electromagnetic response characteristics. This work provides a simple strategy for constructing an ultrathin and ultralight composite to achieve efficient absorption of electromagnetic waves.

Hydraulic valve design methodology for hydro turbine control system

The control of the turbine and its equipment in a hydroelectric power plant requires the HPU (hydraulic power unit) to deliver large volumes of working fluid in a short time at specific optimum control parameters. The use of typical proportional flow control valves created by manufacturers of hydraulic components in low-pressure control systems is disadvantageous due to high pressure losses in the control chambers. This paper presents the methodology and test results while designing a hydraulic proportional valve for low pressure and high flow rate operation. CFD (computational fluid dynamics) theory was analyzed and characteristic values were determined. The validation of CFD tests through those on the test bench was carried out, correction factor was determined. A new proprietary solution was developed and a series of simulation studies were carried out to determine the flow characteristics depending on the degree of the opening of the proportional flow control valve.

Observer-based leader-centric time-varying formation tracking control for nonlinear multi-agent systems with collision avoidance

The article introduces a novel control design methodology to achieve leader-centric time-varying formation tracking (TVFT) with collision avoidance in Lipschitz nonlinear multi-agent systems (MASs) equipped with a leader-driven formation system. This methodology addresses challenges such as actuator bias faults and leader maneuvering within this MASs setup. It employs two control schemes: collision avoidance and a novel formation observer-based time-varying formation tracking (FO-based TVFT) control. These control schemes work in tandem. The collision avoidance scheme ensures safe operation by preventing inter-agent collisions, while the novel FO-based TVFT control scheme enables followers to achieve leader-driven formations while tracking the leader’s movements. To achieve this capability, each follower employs a formation observer (FO) that continuously estimates the leader’s dynamically driven formations throughout runtime, facilitating responsive formation tracking by the followers. Notably, this FO-based TVFT control scheme establishes a novel framework for integrated leader-driven formation switching and leader tracking (i.e., leader-centric TVFT) in MASs. Furthermore, this control methodology is specifically designed for Lipschitz nonlinear MASs susceptible to challenges like actuator bias faults and leader maneuvering. It guarantees that the followers’ collective formation tracking error is uniformly ultimately bounded (UUB), based on Lyapunov’s stability theory. Finally, an illustrative example validates the proposed approach’s effectiveness.

What Is Known from the Existing Literature about Hypopressive Exercise? A PAGER-Compliant Scoping Review.

Introduction: Hypopressive exercise (HE) can be viewed as a mind-body activity, characterized by the integration of breath control and stretching postures. Proponents of HE claim that this type of training can offer potential therapeutic or health benefits. To date, there is no existing comprehensive published overview on HE. This scoping review aims to map and summarize the current literature reporting data on HE and identify key knowledge gaps and future research directions. Methods: This review considered studies that report on the immediate, short-, or long-term practice of HE regardless of condition, sex, age, and/or level of practice or physical condition. Any context or setting was considered for inclusion. This review was performed in accordance with the methodological framework proposed by the Joanna Briggs Institute and by Arksey and O'Malley. MEDLINE, CINAHL, SPORTDiscus, Scopus, and Web of Science were searched from inception up to July 2023. Literature was mapped following the Patterns-Advances-Gaps-Evidence for Practice Recommendations framework to identify patterns and inform practice. Results: In total, 87 studies were identified that reported on the following themes: (1) therapeutic application of a short- or long-term HE programs (n = 56); (2) physiologic and physical responsiveness to a short- or long-term HE programs (n = 22); (3) psychologic and behavioral response to a short-term HE program (n = 14); and (4) acute or immediate physiological responses (n = 21). Literature gaps included poor methodological design, incomplete reporting of intervention, lack of male participants, and exploration of muscle groups distinct from the pelvic floor and abdominal muscles. Discussion: There is a need for high-quality randomized controlled trials, adherence to reporting guidelines on exercise, and the use of active control groups to verify clinical significance, the dose response, and health applications of HE.

Design and Experimental Verification of Electric Vehicle Battery Charger Using Kelvin-Connected Discrete MOSFETs and IGBTs for Energy Efficiency Improvement

This research investigates the advantages of Kelvin-connected 4-pin discrete transistors, both MOSFETs and IGBTs, in onboard battery chargers for electric vehicles. The study compares the standard 3-pin and the extended 4-pin packages based on averaged data collected from leading manufacturers. The investigation shows significant potential power loss reduction, thermal operation mitigation, and reduced gate-drive oscillation for the 4-pin package. The benefits have been quantified by analysing the operation of actual switches in an automotive battery charger based on Boost-PFC and DC-DC LLC converters. The converters’ practical design demonstrates a procedure for integrating the Kelvin-connected package into the design methodology. The results have been verified experimentally.