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Multi‐arm multi‐stage (MAMS) platform trials efficiently compare several treatments with a common control arm. Crucially MAMS designs allow for adjustment for multiplicity if required. If for example, the active treatment arms in a clinical trial relate to different dose levels or different routes of administration of a drug, the strict control of the family‐wise error rate (FWER) is paramount. Suppose a further treatment becomes available, it is desirable to add this to the trial already in progress; to access both the practical and statistical benefits of the MAMS design. In any setting where control of the error rate is required, we must add corresponding hypotheses without compromising the validity of the testing procedure.To strongly control the FWER, MAMS designs use pre‐planned decision rules that determine the recruitment of the next stage of the trial based on the available data. The addition of a treatment arm presents an unplanned change to the design that we must account for in the testing procedure. We demonstrate the use of the conditional error approach to add hypotheses to any testing procedure that strongly controls the FWER. We use this framework to add treatments to a MAMS trial in progress. Simulations illustrate the possible characteristics of such procedures. [ABSTRACT FROM AUTHOR]

The operational effectiveness of a railroad track robot that is designed for railcar undercarriage inspection is provided. Beyond describing the robot's design details and onboard imaging system, the paper analyzes the recorded video images and offers design improvements to increase their clarity. The robot is designed to be deployed trackside, traverse over the rails, and then maneuver in between the rails beneath a stopped train in a siding or a railyard. The under-carriage conditions are documented by onboard video cameras for automated or manual postprocessing. The intent is to inspect the components that are not visible to the conductor or train inspector during a walk-along inspection of a stationary train. An assessment of the existing design, followed by modification and validation, is presented. The results from a prototype unit developed by the Railway Technologies Laboratory at Virginia Tech (RTL) indicate that with proper positioning of off-the-shelf imaging systems such as cameras manufactured by GoPro® in San Mateo, CA, USA and appropriate lighting, it is possible to capture videos that are sufficiently clear for manual (by a railroad engineer), semi-automated, or fully automated (using Artificial Intelligence or Machine Learning methods) inspections of rolling stock undercarriages. Additionally, improvements to the control, mobility, and reliability of the system are documented, although reliability throughout operation and the ability to consistently climb out of the track bed remain points of future investigation. [ABSTRACT FROM AUTHOR]

Study region: The Great Rift Valley Basin of Ethiopia, Arata-Chufa (100 ha) and Ketar (430 ha) irrigation schemes. Study focus: Sedimentation triggers malfunctioning in irrigated agriculture by decreasing canal discharge capacity and increasing operation and maintenance costs. The current study coupled a hydrodynamic sediment model with the output of an erosion model to analyse sedimentation problems, employing data on discharges, water levels, sediment load, and sediment concentration collected over two years (September 2017 to September 2018). The effects of design (canal lining, building a settling basin, and changing longitudinal bed slope) and operational (sediment flushing) modifications on sediment reduction were simulated with the Hydrologic Engineering Center's (HEC) River Analysis System (HEC-RAS) model. New hydrological insights for the region: The model simulation indicates that the most promising low-cost option to reduce sedimentation is flushing during the rainy season, reducing deposition by 82% (Arata-Chufa) and 57% (Ketar). The second option is lining the canal, particularly for a scheme mainly experiencing river sediment like Arata-Chufa, where deposition would be reduced by 28%. Construction of a new settling basin with a flushing option would reduce deposition by 63% (Arata-Chufa) and 42% (Ketar). Changing the bed slope of the severely silted canal section has little effect on sediment reduction. Therefore, operational changes are more promising low-cost options than design modification to reduce sediment deposition in SSI schemes.

In this research, the dynamic response of a U-12 CubeSat (20x20x30 cm) is investigated for three configurations during the launch conditions. Despite the existence of a successful design for this satellite, adding a mount to install on a standard adapter, the structural design of the satellite has been modified for modal computability with the launcher., which is based on 3 general approaches: to apply geometric changes to the structure, changing the extent of the points to improve the limitations of connecting to the launcher, and rearranging the internal system components regarding the standards and principles of compatibility and proximity. Therefore, more than the addition of the adapter mount and a few changes in the separating plates, a spire has been added to the structure, which has caused a change in the internal arrangement, including the halving of the fuel tank (by reducing the capacity of 595 cubic centimeters). Despite the increase of 370 grams of total mass, the natural frequencies of the system have been increased enough without the need for redesign and there will be no frequency interference with the frequency spectrum of the launcher.

The operational effectiveness of a railroad track robot that is designed for railcar undercarriage inspection is provided. Beyond describing the robot’s design details and onboard imaging system, the paper analyzes the recorded video images and offers design improvements to increase their clarity. The robot is designed to be deployed trackside, traverse over the rails, and then maneuver in between the rails beneath a stopped train in a siding or a railyard. The under-carriage conditions are documented by onboard video cameras for automated or manual postprocessing. The intent is to inspect the components that are not visible to the conductor or train inspector during a walk-along inspection of a stationary train. An assessment of the existing design, followed by modification and validation, is presented. The results from a prototype unit developed by the Railway Technologies Laboratory at Virginia Tech (RTL) indicate that with proper positioning of off-the-shelf imaging systems such as cameras manufactured by GoPro® in San Mateo, CA, USA and appropriate lighting, it is possible to capture videos that are sufficiently clear for manual (by a railroad engineer), semi-automated, or fully automated (using Artificial Intelligence or Machine Learning methods) inspections of rolling stock undercarriages. Additionally, improvements to the control, mobility, and reliability of the system are documented, although reliability throughout operation and the ability to consistently climb out of the track bed remain points of future investigation.

Modern hip arthroplasty still faces the issue of wear in the articulating surface and wear induced debris. Thus, the design of hip implant is highly important for its longevity. Experimental demonstration of wear in hip implant involves both time and cost and, in this regard, finite element analysis acts as a suitable alternative. In this work, the wear characteristics of design modified and surface modified femoral head is studied. Femoral head is assumed to be made of Ti6Al4V and liner material is taken as UHMWPE. Design of the femoral head is modified by providing grooves on the femoral head as well as by providing an additional liner on the femoral head surface. Surface of the femoral head is modified with square or circular dimples. This work involves the development of femoral head model and its simulation using ANSYS under static load condition to get the contact pressure and sliding distance. Modified Archard's wear equation uses the contact stress and sliding distance to determine the wear volume produced per year and the obtained results are compared with that in the available literature. The study shows that the wear rate reduced up to 10% by surface modification and 3% by design modifications.

Low/zero-head cross-flow turbines (LZH-CFT) possess vast potential in the field of renewable energy technology. This research presents a modified design of a cross-flow turbine specifically engineered to harness the untapped hydro-kinetic energy from low/zero-head water resources. Unlike traditional hydro turbines, the LZH-CFT leverages a cross-flow configuration to utilize the water flows of natural streams, making it an ideal solution for flow channels with low/zero head. The design is modified through ANSYS simulations by varying the rotor's blade angles (from 0 to 90°) and 60° angle is found optimum. The prototype model of modified design is prepared and tested, which represents 62.5% RPM efficiency and provides double power as compared to the typical cross-flow turbine. [ABSTRACT FROM AUTHOR]

Due to the expansion of residents, the consumption of non-renewable energy increased enormously, thus indirectly increasing pollution and affecting the surroundings. To reduce pollutions in the surroundings, it is recommended to choose non-conventional energy sources. By satisfying this, we can probably decrease the non-renewable sources of energy, by consuming the solar power in day-to-day life in the application of food drying process. In this review article, we have discussed the classification of solar dryer and the impact of design modifications performed in the components of solar dryer and assessed the various types of solar dryer performance, cost estimations and designs performed in solar dryer of food applications which were not discussed in the earlier research. The primary and critical task in designing the solar dryer is to achieve higher efficiency at minimum cost. Hence, proper analysis of drying application, selection of suitable components and suitable design must be carried out to attain efficient dryer. Considering these characteristics, this paper primarily focuses on the effective design parameters incorporated with various efficiency enhancement processes of the solar dryer in the applications of food drying techniques. Thus, this review paper delivers the various classifications, design parameters, performance enhancement methods, properties and valuable assets of solar dryer, which helps to develop the sustainable green eco-friendly environment most primarily, in the application of food drying process. This review article concreted the way for upcoming considerations and provided the techniques for the studies to convey the work for promoting method enhancements. [ABSTRACT FROM AUTHOR]

The paper presents several modifications of a vacuum chamber of the designed fusion neutron source (DEMO-FNS), which will improve its reliability and safety. Employment of a "double" internal shell makes it possible to decrease the temperature and thermal stresses in it. Modifying the outer shell design makes it possible to decrease the thermal load on cryogenic thermal shielding. Changing the water flow scheme inside the vacuum chamber body ensures reliable cooling of iron-water shielding in it. The method of thermal calculations is described. The proposed modifications will be used in other fusion designs. [ABSTRACT FROM AUTHOR]

Although additive manufacturing (AM) enables designers to develop products with a high degree of design freedom, the manufacturing constraints of AM restrict design freedom. One of the key manufacturing constraints is the use of support structures for overhang features, which are indispensable in AM processes, but increase material consumption, manufacturing costs, and build time. Therefore, controlling support structure generation is a significant issue in fabricating functional products directly using AM. The goal of this paper is to propose a knowledge-based design algorithm for reducing support structures whilst considering printability and as-printed quality. The proposed method consists of three steps: (1) AM ontology development, for characterizing a target AM process, (2) Surrogate model construction, for quantifying the impact of the AM parameters on as-printed quality, (3) Design and process modification, for reducing support structures and optimizing the AM parameters. The significance of the proposed method is to not only optimize process parameters, but to also control local geometric features for a better surface roughness and build time reduction. To validate the proposed algorithm, case studies with curve-based (1D), surface-based (2D), and volume (3D) models were carried out to prove the reduction of support generation and build time while maintaining surface quality. [ABSTRACT FROM AUTHOR]

Low/zero-head cross-flow turbines (LZH-CFT) possess vast potential in the field of renewable energy technology. This research presents a modified design of a cross-flow turbine specifically engineered to harness the untapped hydro-kinetic energy from low/zero-head water resources. Unlike traditional hydro turbines, the LZH-CFT leverages a cross-flow configuration to utilize the water flows of natural streams, making it an ideal solution for flow channels with low/zero head. The design is modified through ANSYS simulations by varying the rotor’s blade angles (from 0 to 90°) and 60° angle is found optimum. The prototype model of modified design is prepared and tested, which represents 62.5% RPM efficiency and provides double power as compared to the typical cross-flow turbine.

Water‐cooled copper tuyeres of blast furnace are subjected to intense thermal conditions. Several modifications are attempted to prevent tuyere failure as the impact of failure is severe. What has, however, gone unnoticed is the peak "Cold face" temperature in tuyere and its implication. Numerical model incorporating water flow and conjugate heat transfer with a feature to identify onset of boiling by analytical correlations is developed. It is ascertained that, in tuyeres, the temperature of the Cold face exceeds the saturation temperature at the prevailing pressure by an amount high enough to cause nucleate boiling. The implication of the onset of boiling is discussed and a design modification is suggested by changing the aspect ratio of cooling passage. The impact of velocity distribution to achieve lower peak "Cold face" temperature is discussed. Modified design shows almost zero boiling prone zone for the range of operating parameters studied. Fourteen modified tuyeres are placed alongside original designed tuyeres in an blast furnace. The newly designed tuyeres outperform their counterparts. This approach to identifying and suppressing boiling of water in the cooling channel—a hitherto neglected phenomenon—gives an additional input towards designing a more robust tuyere. [ABSTRACT FROM AUTHOR]

The gold standard for interventional studies is the randomized controlled trial (RCT). The RCT follows a linear path with prespecified plans and a little option for flexibility within its implementation. The RCT is also resource and time-intensive and can be a limitation in epidemics or pandemics where more rapid responses can reduce adverse effects. Adaptive designs (ADs) allow for continuous evidence-based modifications to key elements of trial design even as data collection is going on. Reduced use of resources, reduced time to complete the trial, flexibility in the allocation of participants to study arms and improved likelihood for scientifically valid trial results are added advantages with AD. ADs can be applied from early-phase trials to confirmatory trials. In this paper, we introduce key aspects of AD that Ophthalmologists can apply to clinical trials in Ophthalmology. We briefly introduce the rationale for AD, commonly used terminology, and design elements.

Most of the people living in developing or less developed countries have limited earning to provide somehow their basic needs & usual staff. Carrying goods is a regular task in life & several products have been invented to minimize efforts in this purpose. But the product’s price & features are not optimum for the people of fewer earnings. Stair climbing cart is very useful for those houses where a lift is not available and goods have to be carried frequently upstairs. In this research, the mechanical design has been modified so that the manufacturing cost can be minimized. Finite element analysis has been performed upon the design to find out how the manufacturing cost can be reduced by making the design optimal for manufacturing cost and process. The result shows that the structural members should not be processed further because any tooling operation will require an extra machine as well as an extra cost. Only the wheels are possible to subject under optimization by reducing material as well as weight. This article will be a valuable asset for the mass manufacturers of this type of product.

This work reviews the current operational condition and activities on design modification for different applications of ejectors. Ejectors being a simple mechanical system capable of performing multiple fluid related functions (vacuum generation, pumping, mixing, condensing and heat exchanging), have been an essential part of several industrial processes. Two areas have been emphasized; internal flow and application-based modifications in components of ejectors. The geometry and inlet flow conditions were found to be the prime influencing factor of its performance. The objective and application-based modifications were performed on the primary nozzle, secondary nozzle, mixing chamber, throat and diffuser. The resultant performance was found to be dependent on operational condition and fluid type. This emphasizes the requirement of application-based design selection of the technology. In addition, the flow dynamics of condensing, non-condensing, particle and slurry flow has been studied based on available literatures. The one-point final objective is to identify the usability of primary water jet ejectors for active vapor transport and condensation, to replace vacuum pump and condenser in compact domestic water desalination system. [ABSTRACT FROM AUTHOR]

Although additive manufacturing (AM) enables designers to develop products with a high degree of design freedom, the manufacturing constraints of AM restrict design freedom. One of the key manufacturing constraints is the use of support structures for overhang features, which are indispensable in AM processes, but increase material consumption, manufacturing costs, and build time. Therefore, controlling support structure generation is a significant issue in fabricating functional products directly using AM. The goal of this paper is to propose a knowledge-based design algorithm for reducing support structures whilst considering printability and as-printed quality. The proposed method consists of three steps: (1) AM ontology development, for characterizing a target AM process, (2) Surrogate model construction, for quantifying the impact of the AM parameters on as-printed quality, (3) Design and process modification, for reducing support structures and optimizing the AM parameters. The significance of the proposed method is to not only optimize process parameters, but to also control local geometric features for a better surface roughness and build time reduction. To validate the proposed algorithm, case studies with curve-based (1D), surface-based (2D), and volume (3D) models were carried out to prove the reduction of support generation and build time while maintaining surface quality.

Standard 1D3D mechanical cyclone with standard inlet velocity of 16m/s and cylinder diameter of 0.1524m was modified using Downhill simplex method to develop four modified cyclone designs. Computational Fluid Dynamics (CFD) formulation involving model design, meshing, CFD simulation and postprocessing was carried out on the mechanical cyclones. ANSYS Fluent software was used for the CFD formulation using fine mesh of the default minimum mesh size of the CFD mesher. Cornstarch was used as inlet particulate matter. Reynolds Stress Turbulence Model (RSTM) was used to model the swirling turbulent flow while Discrete Phase Model (DPM) was used to track about 10,000 particles through the simulated cyclones. The DPM result of each mechanical cyclone was used to calculate it’s CFD, particle collection efficiency result. Standard 1D3D mechanical cyclone obtained particle collection efficiency result of 87.38% using cornstarch and default minimum mesh size for CFD simulation while modified 1D3D mechanical cyclone one (1) recorded the optimal CFD particle collection efficiency result among modified 1D3D mechanical cyclones with 94.00%. Its convergence iteration point also showed improvement in simulation time compared to the standard 1D3D mechanical cyclone. Consequently, it was concluded that, design modification in line with CFD formulation offers an alternative and powerful approach to modeling 1D3D mechanical cyclones performance. [ABSTRACT FROM AUTHOR]

Abstract Adaptive designs can make clinical trials more flexible by utilising results accumulating in the trial to modify the trial’s course in accordance with pre-specified rules. Trials with an adaptive design are often more efficient, informative and ethical than trials with a traditional fixed design since they often make better use of resources such as time and money, and might require fewer participants. Adaptive designs can be applied across all phases of clinical research, from early-phase dose escalation to confirmatory trials. The pace of the uptake of adaptive designs in clinical research, however, has remained well behind that of the statistical literature introducing new methods and highlighting their potential advantages. We speculate that one factor contributing to this is that the full range of adaptations available to trial designs, as well as their goals, advantages and limitations, remains unfamiliar to many parts of the clinical community. Additionally, the term adaptive design has been misleadingly used as an all-encompassing label to refer to certain methods that could be deemed controversial or that have been inadequately implemented. We believe that even if the planning and analysis of a trial is undertaken by an expert statistician, it is essential that the investigators understand the implications of using an adaptive design, for example, what the practical challenges are, what can (and cannot) be inferred from the results of such a trial, and how to report and communicate the results. This tutorial paper provides guidance on key aspects of adaptive designs that are relevant to clinical triallists. We explain the basic rationale behind adaptive designs, clarify ambiguous terminology and summarise the utility and pitfalls of adaptive designs. We discuss practical aspects around funding, ethical approval, treatment supply and communication with stakeholders and trial participants. Our focus, however, is on the interpretation and reporting of results from adaptive design trials, which we consider vital for anyone involved in medical research. We emphasise the general principles of transparency and reproducibility and suggest how best to put them into practice.

This work reviews the current operational condition and activities on design modification for different applications of ejectors. Ejectors being a simple mechanical system capable of performing multiple fluid related functions (vacuum generation, pumping, mixing, condensing and heat exchanging), have been an essential part of several industrial processes. Two areas have been emphasized; internal flow and application-based modifications in components of ejectors. The geometry and inlet flow conditions were found to be the prime influencing factor of its performance. The objective and application-based modifications were performed on the primary nozzle, secondary nozzle, mixing chamber, throat and diffuser. The resultant performance was found to be dependent on operational condition and fluid type. This emphasizes the requirement of application-based design selection of the technology. In addition, the flow dynamics of condensing, non-condensing, particle and slurry flow has been studied based on available literatures. The one-point final objective is to identify the usability of primary water jet ejectors for active vapor transport and condensation, to replace vacuum pump and condenser in compact domestic water desalination system.

Modern hip arthroplasty still faces the issue of wear in the articulating surface and wear induced debris. Thus, the design of hip implant is highly important for its longevity. Experimental demonstration of wear in hip implant involves both time and cost and, in this regard, finite element analysis acts as a suitable alternative. In this work, the wear characteristics of design modified and surface modified femoral head is studied. Femoral head is assumed to be made of Ti 6 Al 4 V and liner material is taken as UHMWPE. Design of the femoral head is modified by providing grooves on the femoral head as well as by providing an additional liner on the femoral head surface. Surface of the femoral head is modified with square or circular dimples. This work involves the development of femoral head model and its simulation using ANSYS under static load condition to get the contact pressure and sliding distance. Modified Archard's wear equation uses the contact stress and sliding distance to determine the wear volume produced per year and the obtained results are compared with that in the available literature. The study shows that the wear rate reduced up to 10% by surface modification and 3% by design modifications., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jaber E. Abu Qudeiri, Asarudheen Abdudeen, Mini Rema Sahadevan, Anantha Padmanabhan M has patent #US 11, 672, 666 B1 issued to United Arab Emirates University, Alain., (© 2024 The Authors.)

A design modification to an existing border termination for active‐edge planar radiation detectors is proposed, which enables a dead area reduction and a much larger breakdown voltage to be achieved, with a minor increase in the fabrication complexity. 'Technology Computer‐Aided Design' simulations allowed the device performance of different variants of the proposed structure to be investigated also in comparison with the existing one. Among considered designs, the new border terminations with 2(3) guard rings, featuring a dead area at the edge of ∼90(120) μm, can withstand more than 375(500) V for all oxide charge density values up to 3 × 1012 cm−2. These characteristics make them appealing for X‐ray imaging applications at free‐electron laser facilities. [ABSTRACT FROM AUTHOR]

Highlights • Simulation and shaking table test was done to identify the vibration characteristics of drain pipe. • Natural frequency, mode shape, and transmissibility were determined and compared. • The new design is expected to successfully suppress the vibration response. • Additional design change may be needed for further vibration reduction. Abstract The drain pipe of the steam generators in nuclear power plants is designed to remove the remaining reactor coolant when the nuclear power plant stops. In the normal electricity generating condition of the nuclear power plant, the drain pipe acts as the pressure boundary between the primary coolant system and outside, which forbids the radioactive coolant to be leaked. Therefore, it is important to assure the structural integrity of the drain pipe, which is closely related with the vibration characteristics of the drain pipe. In this paper, the vibration characteristics of the previous and newly designed drain pipes are investigated by simulation and measurement with the shaking table test. The purpose of the new design was to suppress the excessive vibration in the interested low and high frequency ranges, which were observed in the power uprating of plants. From the measured results, in y direction, the first three modal frequencies are increased by 5, 18, and 50 Hz in the low frequency region, and the higher order modes are excluded in the interested high frequency region with the adoption of the new design. Further design modification is required to reduce the high frequency vibration in x direction with other approaches. In general, it is expected from the result that the newly designed drain pipe is more robust to the existing vibration compared with the previous one. [ABSTRACT FROM AUTHOR]

The efficiency and fault tolerance of biogas plant depends on the proper mixing of the sludge in the digester. The quality of mixing can be numerically evaluated based on the velocity profile in the digester. Most of the earlier studies have been focused on improving these velocity patterns with the help of impellers, which requires extra energy to drive them. The current study explores a passive approach for improving velocity pattern by providing the static flaps of optimal sizes at optimal locations. The design optimization problem is formulated to maximize the surface and domain velocities in the digester by varying the geometries and locations of flaps. Sufficient surface velocity gives an advantage by preventing the process of scum formation whereas the improved domain velocity improves gas production rate by improving contact between biomass flocks and the substrate. This concept is demonstrated through the numerical results obtained using CFD and optimization tools of COMSOL Multiphysics software. [ABSTRACT FROM AUTHOR]

In linear models having near collinear columns of X, ridge and surrogate estimators often are used to mitigate collinearity. A new class of estimators is based on mixtures, either of X and a design minimal in an ordered class or of the Fisher information and a scalar matrix. Comparisons are drawn among choices for the mixing parameter, and the estimators are found to be admissible relative to ordinary least squares. Case studies demonstrate that selected mixture designs are perturbed from the original design to a lesser extent than are those of the surrogate method, while retaining reasonable efficiency characteristics. [ABSTRACT FROM AUTHOR]