Design Changes Research Articles

Integration of structural designers’ workflows into BIM

BIM has revolutionized architectural design workflows. In this process, the work of structural engineers relies on the work of many other disciplines, and their decisions are input data for them. However, these data are not always provided in a structured form. Live load and composite load values are typically such data, that may frequently change during the design process. This research explores BIM-based tools for interdisciplinary collaboration between architectural and structural disciplines, with a focus on managing design changes and ensuring that load data is available as early as possible in the design process. In this article, automatic load definition possibilities were explored and adapted to the BIM methodology by using Archicad, Revit, and Allplan. The software options and their logic differ greatly, therefore the proposed methodology can be applied most seamlessly in Archicad. It was demonstrated that by linking the composite structure database to the model, the loads from the built-in materials and the room functions can be generated and updated semi-automatically in response to design changes.

Employee and Supervisor Perceptions of a Policy Promoting Standing in the Workplace: A Qualitative Study

Many employees have jobs that predominantly require sitting, and reducing sitting time to improve physical health has been a focus of health research. A widespread environmental design change is the incorporation of sit-stand desks. Since the workplace plays a large role in a person’s day-to-day activities, researchers and environmental designers must still assess how joint optimization can be reached to satisfy worker well-being and performance. We conducted a qualitative research study to determine how support and/or concern over a hypothetical policy to increase standing in a predominantly seated workplace would differ between those with and without job supervisory tasks. Employees saw the benefits of reducing their sitting time at work and welcomed the added autonomy. Others saw this as infringing their autonomy, uncertainty about how this would affect their tasks, if they would have appropriate equipment, and if the policy was inclusive to people with difficulty standing.

Adapting the design of the ongoing RAMPART trial in response to external evidence: An example for trials which take many years to run and report

Clinical trials to establish the efficacy of new agents in the adjuvant cancer setting typically take many years to complete. During that time, external factors can impact recruitment and reporting plans. An example is a new standard of care becoming available during the recruitment period.In this paper we describe how we modified the design of the RAMPART trial (NCT03288532) which was set up to investigate immune checkpoint inhibitor therapy in the adjuvant renal cancer setting. The trial had been initiated when no globally accepted adjuvant strategy after nephrectomy existed. A subsequent change in the standard of care for many patients with early renal cancer meant it was no longer feasible to continue to recruit. We needed to find a way to maximise the contribution that RAMPART participants could make to the evidence base for immune checkpoint inhibitor therapy without introducing bias or detriment to the integrity of the trial results. We describe how we agreed and incorporated all design and timeline changes while remaining blinded to accumulating data within the trial, thus protecting the reliability of the future results. We share details of our design modifications to guide others who may have similar experiences, particularly as more agents and combinations of agents are developed and investigated in similar adjuvant settings.

Behavioral Design Strategies Improve Healthy Food Sales in a Military Cafeteria.

This study examined the use of behavioral design strategies to improve healthier food sales. A quasi-experimental, one-group, repeated measures design examined changes in food sales following behavioral design adjustments. United States military base hospital dining facility. U.S. military service members, retirees, and civilian employees. Behavioral design changes included placement, layout, messaging, default healthy bundling, a stoplight rating system, strategic positioning of healthy items on menu boards, and an increase in healthier snacks. Food sales were assessed by point-of-sales data. T-tests examined total sales of each food adjusted weekly between baseline and intervention and intervention and post-intervention. 16 food items targeted by the intervention were examined. Weekly food sales were calculated for the 18-week baseline, 18-week intervention, and 9-week post-intervention. Further, analysis estimated negative binomial models for food item sales. The hospital dining facility served 600 to 900 meals per day. Weekly foods sales decreased during the intervention for desserts, cooked starches, hummus, and yogurt (P < 0.01). Sales increased during the intervention for fruit cups, cooked vegetables, vegetable and turkey burgers, grilled chicken, packaged salads, French fries, hamburgers, and hot dogs (P < 0.02). This study demonstrates that a mixture of behavioral design strategies can be operationalized with reasonable fidelity and can lead to increases in the sales of some healthy foods in military worksites.

GTP-24-1666 - Temperature Margin Calculation During Finite Element Creep Simulations (GT2024-121776)

Abstract Creep deformation in turbomachinery applications is a highly non-linear phenomenon where +/- 15°C may halve or double the average rupture life. Even in well-controlled laboratory conditions, this stochastic nature means that identical tests may differ by a factor of two. Analysts using implicit finite element user creep subroutines may not appreciate the uncertainty of their solution, or the design changes required to account for uncertainty in either the boundary conditions or the solution itself. Designing to a maximum strain limit does not consider the sudden acceleration of tertiary creep rates. Applying a time factor may extend the simulation time by multiple factors. This paper presents a methodology where two estimations of creep damage are made in parallel to the creep simulation at actual operating temperatures. These two estimations consider the predicted change in stress relaxation, at higher or lower temperatures, to estimate the temperature change required to reach the onset of creep, at any given node in the model, and at any given time in the analysis. This margin calculation is expanded to consider the uncertainty in creep prediction. A time-based scatter factor is incorporated into the temperature margin calculation to provide a minimum temperature margin that includes model uncertainty. The analyst can also consider the uncertainty of the temperature prediction and boundary conditions to produce a robust creep prediction in a real-world simulation. The methodology is validated through the FEA of example cases and applied to a creep-limited 2nd stage turbine blade.

Influence of proximal femoral morphology on osteointegration of the AMIS uncemented femoral stem in modern hip arthroplasty

BackgroundIndications for total hip arthroplasty (THA) have evolved over recent decades, with a growing trend toward operating on younger and more active patients. With this shift in patient demographics, there has been a change in femoral stem designs and proximal femoral morphology encountered. This study aimed to evaluate the potential correlation between femoral stem osteointegration and proximal femoral morphology using the Dorr and Noble classifications.Materials and methodsWe conducted a retrospective review of 122 uncemented femoral stems (AMIstem Medacta, triple tapered). The demographic data analyzed included sex, age, stem size, and surgical indications. Preoperative radiographs were reviewed to determine the Dorr classification as well as the canal-to-calcar isthmus ratio, cortical index, and canal flare index. Postoperative radiographs were carefully reviewed to identify the presence of potential postoperative radiolucencies. Inter- and intra-observer agreements for these parameters were also analyzed.ResultsSignificant radiolucencies (> 2 mm) were found in 19.5% of the patients. Of all the variables analyzed, the cortical index was the only parameter significantly associated with the appearance of clinically significant radiolucency, with a threshold value of 0.62.ConclusionsThe appearance of radiolucencies is multi-factorial. Nevertheless, in this study, a high cortical index (> 0.62), representing the champagne flute morphology, was found to be associated with the development of significant radiolucencies.

Bilingual pre-service teachers’ evolving conceptualizations about curriculum as a hybrid space through multimodal learning experiences

Guided by Cultural-Historical Activity Theory (CHAT), this study examined the effectiveness of multimodal pedagogical processes in a graduate course to help 23 bilingual pre-service teachers (BPSTs) reformulate curriculum for inclusivity. Using sequential multi-methods, quantitative analysis assessed changes in curriculum design using a researcher-generated rubric, and qualitative explorations examined collages, clay creations, and written metacognitive reflections. The study found that the BPSTs significantly reformulated the role of hybridity in curriculum design and revealed four patterns of change: Qualitative maintained radical, qualitative maintained gradual, qualitative not maintained, and no qualitative change. The study illuminates the use of multimodal mediators for BPSTs’ learning.

Multi-Fidelity Aeromechanical Design Framework for High Flow Speed Multistage Axial Compressors

Abstract The development of novel engine architectures is vital in achieving the aviation sector&amp;#x92;s net-zero carbon emission target by 2050. With today&amp;#x92;s digital decade providing support for an accelerated technology maturation, the challenge for turbomachinery design remains to significantly push the limits of current performance within an ambitious development lead time. In this context, it is essential to adopt a design framework where the predictive models or simulations employed target a sufficiently reliable performance assessment. These models must be tailored to the dynamics of evolving industrial design processes, and therefore continuously balance required design flexibility, robust evaluation, appropriate fidelity (i.e. the level of detail and accuracy they provide), and resulting evaluation time. This paper discusses a framework for designing axial compressors and its application to the aeromechanical optimisation of a high-speed compressor rotor. The design environment integrates geometry parametrisation, modular evaluation with different levels of fidelity for the aerodynamic and structural models, and surrogate-based optimisation (SBO) capabilities. It is shown how the combination of a modular sequencing of the different models and the acceleration enabled by high-performance computing (HPC) and machine learning allows for a more advanced preliminary design. A significant gain in isentropic efficiency is attained while satisfying all structural constraints. At the same time, it is demonstrated that the framework is compatible with the characteristics of the preliminary design phase: both in its ability to adapt to cycle and design changes as well as regarding the turnaround time of the optimisation itself.

Long-Lived Triplets from Singlet Fission in Pentacene-Decorated Helical Supramolecular Polymers.

Singlet fission (SF), which involves the conversion of a singlet excited state into two triplet excitons, holds great potential to boost the efficiency of photovoltaics. However, losses due to triplet-triplet annihilation hamper the efficient harvesting of SF-generated triplet excitons, which limits an effective implementation in solar energy conversion schemes. A fundamental understanding of the underlying structure-property relationships is thus crucial to define design principles for cutting-edge SF materials, yet it remains elusive. Herein, we harness helical supramolecular polymers decorated with pentacene side groups to elucidate intermolecular SF dynamics in solution and promote the formation of long-lived mobile triplets. By leveraging the hydrogen bonding-driven assembly of benzene-1,3,5-tricarboxamide (BTA) cores into one-dimensional scaffolds, we direct the organization of appended pentacene motifs into long-range ordered helical frameworks. Dynamic interactions between weakly coupled SF pendants mediate singlet conversion within hundreds of picoseconds, affording triplet quantum yields well above 100%. Moreover, analysis of triplet dynamics with a Monte Carlo simulation model reveals that triplet diffusion along the supramolecular fibers is favored over annihilation, resulting in independent triplets exhibiting considerably slow decay on the time scale of tens of microseconds. The molecular packing within the assembly is tuned by subtle changes in monomer design to increase the rate and efficiency of SF while ensuring exceptionally long-lived mobile triplets, allowing to maintain triplet quantum yields exceeding 100% for at least 100 ns. This work opens new opportunities to exploit self-assembled supramolecular polymers as functional templates to achieve long-lived SF-generated triplets.

The anchoring policy perspective on policy change: mechanisms, applications and analytical challenges

ABSTRACT How functional relationships between policies influence policy design and policy change has received relatively limited attention within public policy scholarship despite the importance of policy coordination. This article contributes to addressing this gap by introducing the Anchoring Policies Perspective (APP), a framework for analysing interactions between policies in functional policy hierarchies. The APP examines how formal links between anchoring policies (AP) and functionally subordinate policies (SP) generate anchoring effects, whereby the provisions codified in APs generate alignment pressures that channel the design of SPs towards the norms and goals of the AP. In the article, we examine the analytical contribution of the APP by analysing the distinguishing characteristics of APs, the mechanisms through which APs influence SP introduction and design, and political strategies for managing situations where resistance occurs to the alignment of SPs with their APs. Examples from environmental and energy policy are used to illustrate key features of the AP-SP relationship, following which the APP’s contribution to public policy scholarship is discussed. We conclude by arguing that the APP has the potential to bring important new insights to the analysis of policy change while building connections with established theories of policy change to develop the APP framework further.

Estimating daily road traffic pollution in Hong Kong using CFD modelling: Validation and application

Road traffic is a major source of urban air pollution, exposing residents to harmful levels of pollutants, particularly in densely populated urban centers. In this study, Computational Fluid Dynamics (CFD) modelling is applied to investigate the impact of road traffic emissions on air pollution within a dense urban environment. The model, applied in Mong Kok, Hong Kong, incorporates high-resolution traffic activity, meteorological, and background concentration data. It demonstrates strong agreement with roadside measurements, deviating by 18.8 % for NOx, 15.5 % for CO, and 0.7 % for PM10, with potential underestimation linked to unmodeled NOx-O3 photochemistry during midday hours (12:00–17:00). Results reveal that local road traffic significantly increases background NOx levels (41 % average increase), highlighting the importance of dispersion modelling for accurate pollution assessments. Traffic-induced increases in CO and PM10 background levels are less pronounced. Two applications demonstrate the model's utility. Firstly, analysis of daily pollution distribution reveals that approximately 10 % of the studied area experiences moderate to very high pollution levels during peak hours. Secondly, an investigation into pollution sources within a leisure park identifies heavy-duty and light-duty vehicles as the primary NOx polluters. This modelling approach provides a valuable decision-making tool for policymakers and local authorities. It enables the assessment of urban design changes, strategic placement of sensitive structures, and future traffic fleet composition choices to mitigate pollution exposure. As air quality regulations tighten, this study offers a robust method for guiding impactful mitigation strategies.

Sound synthesis of geometric and material changes in archtop guitars: towards the timbral design of musical instruments

Through computer simulations and synthesis, our research studies the impact of various geometric and material modifications on archtop guitar sound. We use an accurate and realistic physical guitar model from which the bridge admittance and radiated sound pressure are computed. Subsequently, we synthesise the sound of this instrument via state-of-the-art methods for two different chords. The generated sound is then analysed in terms of traditional timbral descriptors. With this framework, it is possible to hear the design changes that the maker can perform in a guitar, paving the way for its timbral design, and bridging the gap between physical models and perception of sounds in musical instruments.

Thermal management of water electrolysis using membrane distillation to produce pure water for hydrogen production

When electrolysis units are used for water splitting to provide green hydrogen, waste heat must be dissipated to avoid performance degradation. Therefore, the hypothesis was that if a membrane distillation unit could use the waste heat to desalinate the feed water, then the operating costs may be reduced. This study demonstrated the first integration of a 0.03 m2 active area membrane distillation heat exchanger (MDHX) system with a 2.2 kW commercial electrolyser. The MDHX system satisfied the thermal requirements of the electrolysis unit. It was estimated that for a 2GW electrolysis plant, it could result in annual savings of up to $2 million. During operation with the 2.2 kW electrolyser, the MDHX unit was able to produce 50 % of the permeate rate required to match the water consumption of the electrolyser. Experimentally the MDHX system operated with a specific electrical energy consumption of 230 kWh/m3. Design changes such as improving pump efficiency and optimising flow field geometry to allow for lower flow rates, suggest there is scope for reduction in energy consumption. Indeed, further development of the MDHX technology is necessary before it can compete with large-scale seawater reverse osmosis (SWRO) methods.

A-092 Siemens Healthineers Commitment to Quality - A Focus on Continuous Improvement and Customer Experience

Abstract Background It is necessary that each step of in vitro diagnostic assay development and manufacturing processes be documented and executed in alignment with established quality management systems. Here, we describe how Siemens Healthineers (SHS) maintains assay traceability and focus on continuous improvement using the Atellica® CH A-LYTE® Integrated Multisensor Technology (IMT) assays measuring electrolytes sodium (Na), potassium (K), and chloride (Cl) as a prime example. Methods Establishing an unbroken chain of comparison from the National Institute of Standards and Technology (NIST) higher standard references to the product calibrators ensures accurate value assignment within stated measurement uncertainties. Traceability and standardization are achieved by creating a panel of 10 serum anchor pools spanning the analytical measuring interval for each electrolyte: Na, K, and Cl. The concentrations of the anchor pools are determined at a reference laboratory using methods calibrated with standard solutions derived from NIST reference material. These serum anchor pools are used by SHS, assigning values to product calibrator material which maintains the chain of traceability to the primary reference methods. In addition to traceability, onboard stability for the A-LYTE® IMT multisensor is continuously monitored and evaluated against allowable drift limits for each electrolyte. Although observed drift was within allowable limits, a design change was implemented to improve recovery drift over the use life of the sensor. Results To ensure consistent, robust, and accurate performance of the A-LYTE IMT, a strict set of testing procedures are used to verify the accuracy of value assignments for each manufactured lot of master standards. The recovery of the NIST standard reference material must fall within manufacturer established acceptable bias limits. Consistency over nine master lots is shown with bias ranging from -0.9% to +1.9%, -2.4% to +1.8% and -1.8 to +0.5%, for Na, K and Cl, respectively. By further optimizing the amount of Na ionophore and the polymer matrix of the Na sensor, drift over the use life was minimized and onboard stability improved. Prior to making the sensor change, customer Na QC data at 116 mmol/L showed an SD of 1.1 mmol/L (n=585), whereas the precision improved to an SD of 0.6 mmol/L (n=470) post-optimization. As Manufacturers optimize assay performance, it may become necessary for laboratories to re-evaluate reference intervals for their patient populations. For example, one large integrated delivery network established a new reference interval for patient anion gap (AG). A re-evaluation of the historical AG reference interval which was 5-15 mmol/L identified the need for an update. AG values were calculated from 16,948 healthy patients and used to establish a new reference interval of 2-10 mmol/L. Conclusions Accurate clinical laboratory measurements are critical for diagnosing, monitoring, and treating diseases. A-LYTE assays have an unbroken chain of traceability to NIST reference material and minimal drift over the life of the multisensor. Continuous monitoring to identify improvement projects and rigorous control systems ensure sensor performance over time. This provides confidence that the patient results produced by the laboratory are accurate and consistent over time and across different laboratory locations.

Toward building deliberative digital media: from subversion to consensus.

Evidence-based and human-centric design of digital media platforms could reduce many of the problems of misinformation, polarization, and misaligned incentives that plague both society and individual organizations. With these sorts of design changes, it may become possible to build deliberative digital media that are useful both for discussions of contentious issues and for achieving successful collective action. In this Perspective paper, we discuss several issues in which current-day social science indicates the origin of these problems and suggests methods for improvement. Finally, we analyze a popular deliberative democracy platform to illustrate how social science might enable design of next-generation digital media suitable for democratic deliberation, and in which generative artificial intelligence might be useful.

Model-based assembly process planning for flexible aircraft cabin architectures

The configuration and equipment of an aircraft cabin has a significant impact on the passenger’s flight experience. To meet the needs of passengers and improve the flight experience, airlines repeatedly demand customised adaptations to the cabin design. The implementation of these changes requires a high degree of flexibility in production and can lead to difficulties in setting up a fixed final assembly line. In addition, unforeseen events and changes in the OEMs’ supply chain require a rapid response in aircraft production to be able to deliver on time. Digitalisation in product development and production planning makes it possible to overcome these challenges and makes an important contribution to flexibility, time and cost efficiency. This paper presents a digital approach to modelling and flexible planning of assembly processes of the cabin. To this end, aircraft design data is automatically linked to the assembly system to react quickly to design changes in the assembly planning process. The integration is realised in a system architecture model depicted with the systems modelling language (SysML). The architecture model follows the formal process description defined in VDI3682. A planning algorithm then uses the production architecture parameters to optimise the assembly processes, e.g. in terms of time. The approach presented is demonstrated using the example of scheduling the pre-assembly processes of the "crown module". The latter includes all structural and functional components above the window panels, such as overhead bins, electrics and air conditioning. The results show how changes in aircraft and cabin design or in the production plant and resources can be flexibly evaluated. This allows conceptual changes to be evaluated and traded before the cabin design is frozen and transferred to real production. These advantages contribute to the time and cost optimisation of aircraft production. This work thus makes a valuable contribution to the further development of digital solutions in aircraft production.

Modeling Reversible Volume Change in Automotive Battery Cells with Porous Silicon Oxide-Graphite Composite Anodes

Automotive battery manufacturers are working to improve the individual cell and overall pack design by increasing durability, performance, and range, while reducing cost, and active material volume change is a key aspect that needs to be considered during this design process. Recently, silicon oxide-graphite composite anodes are being explored to increase total anode capacity while maintaining a tolerable amount of cell level reversible volume expansion due to the relatively lower reversible volume change of the silicon oxide compared to pure battery grade or metallurgical grade silicon. To predict the blended anode response and contribution to the overall cell volume change, we integrated the mechanical behavior of the individual active materials with the multi-species, multi-reaction model to predict the state-of-lithiation of the active materials in the cell at a given potential. The resulting simulations illustrate the tradeoff in volume change between the silicon oxide and the graphite during cell operation. This type of modeling approach will allow designers to virtually consider the impact of cell level and pack level design changes on overall system mechanical performance for automotive and grid storage applications, namely that relatively small addition of silicon containing materials can drive a significant increase in the volume change at the cell level, as demonstrated by the 5 wt% addition of silicon oxide accounting for half of the overall volume change in the cell.

Towards Integrated Safety Assurance Methodology for Autonomous Vessel Navigation Systems

Abstract Safety assurance remains paramount for the realization of autonomous vessels. A robust assurance methodology that can provide traceability throughout the design and verification process is necessary to demonstrate safety equivalence to that of conventional ships. However, there are few references that propose a holistic safety assurance scheme for autonomous ships, using actual engineering processes of ships as examples. This study proposes a design and development method for an autonomous navigation system that integrates Model-Based Systems Engineering (MBSE), System Theoretic Process Analysis (STPA), Failure Modes and Effects Analysis (FMEA), and several verification methods including simulation-based tests to develop a comprehensive safety assurance scheme. This safety assurance scheme is being conducted as a case study for a newly constructed autonomous vessel. First, STPA can be performed on the conceptual design established by MBSE to extract additional safety requirements from the identified loss scenarios. Focusing on the process model in the loss scenario description leads to a deeper understanding of the system behavior. FMEA in addition identify potential component failure modes and their impact on system safety. The multi-level requirements that emerge from these activities are validated in test scenarios. Simulators are used to evaluate whether the autonomous navigation system’s safety can meet predefined pass criteria in some of the scenarios. These activities ensure traceability from safety goals to design decisions, allowing design changes and their impact on safety to be evaluated throughout the development lifecycle and allowing for more systematic ongoing monitoring during operations.

ID: 333585 Updated Data from Targeted Drug Delivery Product Surveillance Registry: Effect of Pump Durable Design Changes

ID: 333585 Updated Data from Targeted Drug Delivery Product Surveillance Registry: Effect of Pump Durable Design Changes

Modeling movements improves capture–recapture estimates for mobile species with sparse data: Polar bears (Ursus maritimus) in Viscount Melville sound

AbstractWildlife management requires estimates of demographic parameters that are difficult to obtain for mobile species at low densities. Biased parameter estimates often result from capture–recapture (CR) studies due to small sample sizes and unequal recapture probabilities, the latter of which can be caused by animal movements with respect to the sampling area. We developed a multistate CR model designed to minimize biases by including multiple data types (capture, harvest, natural mortality, and telemetry) and accounting for temporary emigration. We applied the model to data collected intensively from 2012 to 2014, and intermittently since the 1970s, for the Viscount Melville (VM) subpopulation of polar bears (Ursus maritimus) in the Canadian Arctic. The number of bears within the VM subpopulation boundary likely increased from an average of 145 (Bayesian 95% credible interval [CRI] [109, 221]) in 1989–1992 to 235 (95% CRI [148, 569]) in 2012–2014. Survival probability increased for all sex and age classes except adult females, for which estimates declined due to unknown reasons. Polar bear movements exhibited Markovian dependence with approximately 28% of the subpopulation located outside of the sampling area each spring. This contributed to inaccurate parameter estimates when using a simpler, single‐state CR model that only included capture data. Although the interpretation of demographic status was complicated by statistical uncertainty and changes in study design, our findings suggest that—as of 2014—the VM polar bear subpopulation had likely recovered from an earlier period of overharvest, was stable, and had not exhibited detectable negative effects of climate warming.