Standard Design Research Articles

Challenges in Urban Data Center Design

The data center market is experiencing significant growth, with each new facility requiring increased power density and cooling needs. This growth brings new challenges, including noise pollution and its impact on nearby communities, which becomes excessively difficult in urban environments. This presentation will explore the issues faced by data centers in urban environments and discuss potential solutions to create quieter facilities. Key points include: Physical challenges: Every site design faces numerous physical constraints, including limited rooftop and equipment room space, tight and complex adjacencies of neighboring sites, and design and performance standards for equipment. Political issues: Every site and community have a different set of laws and regulations that a site needs to meet, and often go beyond to ensure that the community will accept the site. People issues: Data centers must navigate contentious relationships with neighbors and address noise concerns to maintain a positive reputation. By addressing these challenges, data centers can minimize noise pollution and maintain positive relationships with surrounding communities, ensuring a sustainable future for the industry in urban environments.

Calibration of resistance factors for seismic design of masonry infilled frames using the random finite element method

This paper presents a reliability analysis of concrete masonry infill walls with an aim to examine the efficacy of the resistance factor specified in the infill design under seismic loading. A numerical model for masonry infilled reinforced concrete frames was developed and encoded in OpenSees for this study. The model was validated using experimental data. Two features were involved in this reliability study, including 1) that the effect of spatially varying masonry compressive strength f′m on the lateral resistance of masonry infills was considered using the Random Finite Element Method, and 2) that seismic load with different return periods was considered to provide a more complete treatment of a reliability analysis. The study selected six Canadian cities with varying levels of seismic intensity for this analysis. By calculating the probability of failure of infill frames subjected to earthquake loading at different locations, the paper showed that the current resistance factor of 0.6 in the infill design equation suggested by the Canadian masonry design standard is conservative. To achieve a reliability index of 3, this factor could be increased to 0.65 for all cities studied. For cities with low seismicity such as Toronto, the results suggest that an even higher resistance factor is justified.

An experimental study of cold-formed steel connections with screwed clip angle under tension and shear loads

This paper aims to investigate the performance of typical cold-formed steel (CFS) beam-to-beam connections between floor bearers and floor joists through a series of full-scale experiments. The investigated connections consisted of a lipped channel (floor joist), an unlipped channel (floor bearer), a thin-walled clip angle (connector), and a self-drilling screw (fastener). In this study, customised T-shaped and H-shaped CFS connection specimens were tested to examine the performance under tension and shear loads, respectively. Two sizes of self-drilling screws, 10 G and 14 G, were used with the selected load bearing clip angle. The fabricated connection specimens were subjected to displacement-controlled tension and shear loads. The experiments uncovered the ultimate connection strengths, load-displacement relationships, and failure mechanisms of the designed CFS connections under the applied loads. Moreover, the experimental tensile and shear strengths of the connections were compared with the strengths predicted by the standard design equations. It was found that the screw pullout on the anchored leg of the clip angle was the main mode of failure under the tensile load. On the other hand, two different failure modes—fracturing of 10 G screws or shear buckling of the cantilevered leg of the clip angle with 14 G screws—were observed in the H-shaped specimen under the applied shear load. Among the designed connection specimens, the maximum tensile load capacity was 30.86 kN and the maximum shear load capacity 88.15 kN. The standard design calculations predicted screw pullout failure under tension, while the shear bucking failure mode of the clip angle under shear load was overlooked.

Research on Key Points of Design of Standard Plants in Modern Industrial Parks Under the Background of Promoting the Development of New Quality Productive Forces

With the progress of science and technology and the acceleration of industrialization, the modern industrial park is an important carrier of industrial development. The importance of its standard plant design has become increasingly prominent. With the development of new quality productive forces as the background, this research deeply discusses the key points of standard plant design in modern industrial parks. This paper uses literature review and case analysis to systematically analyze the important role of standard plant design in developing new quality productive forces in modern industrial parks and puts forward suggestions for optimizing design. It is found that the rationality, intelligence, and environmental protection of plant design are the key factors affecting the development of new quality productive forces. The paper summarizes the core points of modern industrial park standard plant design to provide a reference for the future development of related industries.

The Strategy of Digital twin Implementation at the Cyber-Physical Enterprises

The strategy of digital twin (DT) implementation at the cyber-physical enterprises is proposed, which is due to the need for high-quality and effective reconstruction of Ukraine. The TISM and MICMAC methods are used to study the factors that influence the strategy of DT implementation to support the guaranteed functioning of a cyber-physical system. 13 main factors, that determine strategy success, were identified, and a model of strategy realization was built in the form of a six-level interaction diagram (digraph). The factors are classified by influence and dependence. The substantiated conclusion is that the state support of DT implementation strategy, the availability of design standards, data protection methods, legislative regulation and implementation experience by other enterprises are key factors to the success of strategy for DT implementation at the enterprise.

Numerical Modelling and Mathematical Modelling of Non-Contact Gripper for Maximum Negative Pressure and Grasping Area

The aim of this paper is to provide a mathematical relationship between the geometrical parameter (cone radius), input parameter (volumetric flow rate) and constraint condition (gap height) with the grasping parameters for non-contact gripper. The cone mill Bernoulli gripper is taken as the reference model. The grasping parameters are negative pressure and grasping area. Thus, to provide the mathematical relation four different cone radius, three volumetric flow rates and three gap heights are taken. With the help of statistical tool (MINITAB) the mathematical relationship is established. A standard full factorial design is chosen to provide the regression equation. With the help of interaction graph the effect of individual parameters on grasping are established. Key Words: Non-contact gripper, Bernoulli, Automation, Grasping area, Negative pressure, Face Radius (FR).

Axial compression behaviour of bamboo-wood composite columns fabricated with glubam and laminated veneer lumber

Both wood and bamboo are natural green biomaterials with a long application history in human society. A novel bamboo-wood composite fabricated with glued laminated bamboo (glubam) and laminated veneer lumber (LVL) was developed to reduce wood resource demand and to promote bamboo utilization efficiency. Experimental and analytical investigations were conducted to study the mechanical performance of 36 bamboo-wood composite columns with different slenderness ratios under axial compression. The three-layer composite column was composed of glubam as outer layers and LVL as a core layer, with horizontal or vertical configurations respectively. The failure modes, ultimate capacity, load and deformation behaviour were evaluated. Strength failure was the typical failure mode of the short columns while buckling was commonly observed for the longer columns. Columns with vertical LVL core had overall better performed with higher compressive strength than the ones with horizontal LVL core configuration. The ultimate load of the composite columns with thin-strip glubam as outer layers were increased by 31.6 % to 45.3 % than those of thick-strip glubam as outer layers. The compressive capacity of the specimens predicted according to three standards were compared with the experimental results. An improved expression considers the material strength and column slenderness ratio was proposed, which provides a better prediction than the current design standards.

Design of grounding scheme for mobile substation

The rational design of a grounding grid is a crucial prerequisite for ensuring the safe and reliable operation of mobile substations. This paper discusses the design of the grounding grid for mobile substations from the perspective of standardized design, aiming to minimize on-site construction and enable rapid deployment. It introduces a type of grounding ring network design that can ensure the entire equipment forms a reliable equipotential grounding, thereby enhancing the operational reliability of mobile substations.

Factors that influence pedestrian walking speed and behavior at crosswalks: a study of three metropolitan areas in Mexico

ABSTRACT Walking is the most common mode of transportation in the world. The design standards may need to be adjusted to local conditions to ensure pedestrian safety in different parts of the world. The paper aim is to find the factors that influence the crossing speed of pedestrians and their behavior in the crosswalk, and thus provide better tools for the design of pedestrian facilities. Thirty crosswalks from four cities in Mexico were analyzed, obtaining a sample of 8700 pedestrian crossing speed records. The results show that land use, median design, pedestrian traffic signals, number of lanes, the day of the week, gender, age, carrying objects, pedestrian platoon size, population, and geographical area are significant factors in pedestrian crossing speed. In addition, it was observed that a significant number of pedestrians exhibit unsafe crossing behaviors. Male pedestrians were found to be more likely to exhibit these unsafe crossing behaviors.

Post-fire behavior and residual resistances of S890 ultra-high strength steel circular hollow sections under combined compression and bending

This paper presents experimental and numerical investigations into the post-fire local buckling behavior and residual resistances of S890 ultra-high strength steel (UHSS) circular hollow section (CHS) under combined compression and bending. The physical testing was firstly conducted and encompassed heating, soaking and cooling of specimens, as well as post-fire tensile coupon tests, measurements of initial local geometric imperfections and eccentrically loaded stub column tests. Then, finite element models were developed and validated with reference to the experimental observations and then adopted for parametric analyses to derive additional numerical data, considering various cross-section dimensions and loading combinations. As a result of the lack of design provisions for ultra-high strength steel structures after exposure to elevated temperatures, the applicability of the relevant ambient temperature design interactive curves given in the current European, American and Australian standards to post-fire S890 UHSS CHS under combined compression and bending was assessed, with post-fire material properties used. The assessment results showed that all design standards exhibited conservative and scattered predictions of residual resistances for S890 UHSS CHS under combined compression and bending at ambient temperature and after exposure to elevated temperatures. The American specification provided more precise predictions of residual failure loads for non-compact and slender (Class 3 and 4) sections than the Eurocode and Australian standard, due to the accurate compression and bending endpoints. In comparison to the American and Australian specifications, the Eurocode resulted in more precise results in predicting residual failure loads of compact (Class 1 and 2) sections, owing to the accurate compression and bending endpoints as well as the nonlinear design interaction curve.

Monolithic integrated circuit LNA 5–10 GHz

One of the features of the current stage of development of microwave electronics is the widespread use of monolithic integrated circuits. The interest of radio-electronic equipment developers in MIS is caused not only by better microwave characteristics compared to modules made using hybrid technology, but also by economic feasibility, ease of setup and reproducibility of parameters of finished products. An integral part of the transmitting and receiving paths of such systems are MMICs of low noise amplifiers. The goal of the work is to implement a matched MIC microwave low-noise amplifier with operating frequencies from 5 to 10 GHz with a noise figure of at least 1.2 dB and a gain of at least 20 dB. To develop an amplifier with operating frequencies up to 10 GHz, technology with a design standard of 0.25 microns was chosen. To meet the requirements, a two-stage circuit with automatic bias was selected. The widths of the transistors were selected taking into account the analysis of the minimum achievable noise figure and the balance between current consumption and output power. The autobias of the first stage is organized using an inductor. This solution allows not only to set the required DC mode, but also ensures input matching of the amplifier. The second stage is covered by negative feedback, which has a positive effect on the stability of the amplifier and its output matching. The amplifier supply voltage is 5 V, while resistors in the DC filter circuits set the required voltage value at the drain of each stage. Based on electrodynamic analysis, a topology was synthesized and an MIC was manufactured in the form of a gallium arsenide crystal 1.8 x 1.8 mm in size and 100 μm thick. An experimental study of manufactured LNA samples showed that in the frequency range from 5 GHz to 10 GHz the noise figure does not exceed 1.2 dB, while the minimum gain in the operating band is 21 dB. Characteristics of the amplifier has good temperature stability. The main parameters of the manufactured microcircuit are at the level of parameters of foreign analogues.

Shared mooring system designs and cost estimates for wave energy arrays

For floating renewable energy devices to become more cost-efficient and commercially scalable, their mooring system designs must be low-cost and suited for large-scale installations. Large arrays of floating devices, such as wave energy converters (WECs), will likely be designed with an individual mooring system for each device in the array. However, new mooring technology advancements provide options to use shared mooring lines to connect adjacent devices to one another, reducing the total number of anchors in the array, thereby reducing material use and cost. This paper explores the design, modeling, and cost analysis of shared mooring systems for various sizes of arrays consisting of heaving oscillating water column (OWC) WECs. Shared mooring systems for WEC arrays sized in 2×N and N×N grid layouts are designed to meet the relevant design standards, checking their performance with a nonlinear time-domain dynamic simulation, and the costs of each are calculated and compared. Several assumptions are taken in the design process to produce efficient results, providing a preliminary optimization for guidance on design decisions rather than a full, detailed design analysis. Mooring system costs per WEC were found to decrease as the number of WECs in the array increase, up to certain array sizes. The 2 × 3 array had the lowest mooring system cost per WEC out of all arrays considered, with a 60% cost reduction relative to using individual mooring systems. The 3 × 3 and 4 × 4 arrays achieved a 50% cost per WEC reduction. In addition to these significant cost reductions, the shared mooring system designs can provide advantages through smaller mooring system footprints, lower installation times, and less seabed disturbance.

Optimal design of selected features of exhaust system shields using different optimization methods and artificial neural networks

The article presents problems related to methods of optimal design of heat shields used in exhaust systems of internal combustion engines. The optimization method proposed in this paper goes well beyond the scope of the standard design process. The paper uses a variety of local and global optimization algorithms, those both built into numerical simulation systems and in-house and external algorithms. An optimization criterion was defined and numerically implemented, together with constraints derived from the real requirements for this type of shielding. A simplified numerical model of finite element method providing the required accuracy adapted to the optimization task was developed. In addition, the work also presents a method for creating finite element surrogate models using artificial neural networks. The process of selecting the network topology and its learning allowed the development of a metamodel characterized by very good quality, for which, despite the relatively large number of design variables, the response errors are completely acceptable from a practical point of view. Numerical results were compared and developed for the used methods and algorithms.

Clinical trial designs to assess treatment effects on glomerular filtration rate decline

Glomerular filtration rate (GFR) decline is used as surrogate endpoint for kidney failure. Interventions that reduce chronic kidney disease (CKD) progression often exert acute GFR reductions which differ from their long-term benefits and complicate the estimation of long-term benefit. Here, we assessed the utility of two alternative trial designs (wash-out design and active run-in randomized withdrawal design) that attempt to exclude the impact of acute effects. Post-hoc analyses of two clinical trials that characterized the effect of an intervention with acute reductions in GFR were conducted. The two trials included a wash-out period (EMPAREG-Outcome testing empagliflozin vs placebo) or an active run-in period with a randomized withdrawal (SONAR testing atrasentan vs placebo). We compared the drug effect on GFR decline calculated from the first on-treatment visit to the end-of-treatment (chronic effect in a standard randomized trial design) with GFR change calculated from randomization to end-of-wash-out, or GFR change from treatment specific baseline GFR values (GFR at start-of-run-in for placebo and end-of-run-in for atrasentan) until end-of-treatment. The effect of empagliflozin versus placebo on chronic GFR slope was 1.72 (95% confidence interval 1.49-1.94) mL/min/1.73m2 /year, similar to total GFR decline from baseline to the end of wash-out period using a linear mixed model 1.64 (1.44-1.85) mL/min/1.73m2 /year). The effect of atrasentan versus placebo on chronic GFR slope was 0.72 (0.32-1.11) mL/min/1.73m2 /year, similar to total slope from a single slope model when estimated from treatment specific baseline GFR values 0.77 (0.39-1.14) mL/min/1.73m2 /year). Statistical power of the two designs outperformed the standard randomized design. Thus, wash-out and active-run-in randomized-withdrawal trial designs are appropriate models to compute treatment effects on GFR decline.

Rehabilitation Using Implants with Sloped Platform Edge vs. Standard Platform with Guided Bone Regeneration: A Randomized Control Clinical Trial.

The purpose of this study was to evaluate the vertical bone loss after using different techniques: sloped implants or standard implants with guided bone regeneration. Patients with tooth gap and horizontal bone deficiency were randomly allocated to the test group (implants with sloped platform-SLP) and control group (standard design implants with guided bone regeneration-GBR). The primary outcome was bone loss (6 months after finishing the prosthetic treatment). Secondary outcomes included the following: patient-reported outcome measures (PROMs), post-operative edema, keratinized mucosa width, and pink aesthetic score (PES). The average bone loss at 6 months was 0.23 ± 0.15 mm and 1.03 ± 0.37 mm in the SLP and GBR groups, respectively. The SLP group was characterized by lower pain intensity the first 7 days (p < 0.001), lower post-operative edema (p < 0.001), lower consumption of NSAIDs on days 1, 3, 5, and 7 (p = 0.002, <0.001, <0.001, and 0.008), and lower total OHIP-14 (p = 0.047) on day 7. The keratinized mucosa width was 3.7 (3.4-4.0) mm and 2 (1.4-2.0) mm in the SLP and GBR groups, respectively. The preservation of the mesial, distal papillae, and the level of soft tissue correspondence were significantly higher in the SLP group (p = 0.003, 0.038, <0.001). In the SLP group, more natural color and better texture of soft tissues were found (p = 0.048, p = 0.041). The use of implants with a sloped platform resulted in superior outcomes compared to the standard-design implants with GBR.

Experimentally estimating wind load coefficients for tornadoes – An alternative perspective

Given the increased interest in tornado-induced wind loading (in part exhibited by inclusion of such loading in wind standards around the world) it is vital to understand the various characteristics of such loading and their relative overall importance. As such, employing a range of types of simulations and simulators would be helpful for understanding and estimating tornado-induced wind load coefficients. This paper advocates a quasi-steady framework to estimate tornado-induced wind loads and identifies the tornado flow characteristics most likely to influence these loads. The flow characteristics discussed include the flow field itself, the static pressure field, vortex translation, flow turbulence, streamline curvature, and flow acceleration. A fundamental conclusion of this paper is that pressure coefficients for tornado-induced wind loading should always be measured and reported as functions of these characteristics. The paper discusses various alternatives for simulating these characteristics and highlights which types of facilities would be effective for studying each one. Such approaches will also require deliberately measuring velocity and static pressure simultaneously with any load measurements made on a building model. This will then help clarify the dependencies of pressure and load coefficients to the various parameters, will limit the parameter space that must be explored to understand extreme loading, and will facilitate easier comparison among different laboratory results, all of which will ultimately lead to improved design standards.

Passive House-based energy efficiency design criteria: a case study of a residential building in Cairo

PurposeThe study aims to tackle Egypt's rising electricity consumption due to climate change and population growth, focusing on the building sector, which accounts for up to 60% of the issue, by developing new energy-efficient design guidelines for Egyptian buildings.Design/methodology/approachThis study comprises six key steps. A literature review focuses on energy consumption and efficiency in buildings, monitoring a single-family building in Cairo, using Energy Plus for simulation and verification, performing multi-objective optimization, comparing energy performance between base and controlled cases, and developing a localized version of the Passive House (PH) called Energy Efficiency Design Criteria (EEDC).FindingsThe research shows that applying the (EEDC) suggested by this study can decrease energy consumption by up to 58% and decrease cooling consumption by up to 63% in residential buildings in Egypt while providing thermal comfort and reducing greenhouse gas emissions. This can benefit users, alleviate local power grid strain, contribute to Egypt's economy, and serve as a model for other countries with similar climates.Originality/valueTo date, no studies have focused on developing energy-efficient design standards tailored to the Egyptian climate and context using the Passive House Criteria concept. This study contributes to the field by identifying key principles, design details, and goal requirements needed to promote energy-efficient design standards for residential buildings in Egypt.

Indoor environmental quality in WELL-certified and LEED-certified buildings

International building certification systems, such as the WELL and Leadership in Energy and Environmental Design (LEED) standards, play a pivotal role in the design of healthy and sustainable buildings. While LEED adopts a holistic approach to designing healthy and sustainable buildings, the WELL standard has a strong emphasis on human health, comfort, and well-being. Although prior research has revealed inconsistent results for occupant satisfaction in office buildings with WELL certification compared to buildings without WELL certification, or are certified using another certification system (e.g., LEED), most of these comparisons tend to lack methodological rigor. This study used a statistical procedure to match and compare 1634 occupant surveys from LEED-certified buildings to 1634 surveys from WELL-certified buildings. Six important architectural and experiential parameters were matched, masking their influence on the outcome. Overall building and workspace satisfaction was high in both WELL-certified buildings (94% and 87%) and LEED-certified (73% and 71%). We found that there is a 39% higher probability of finding occupants who are more satisfied in WELL-certified buildings compared to LEED-certified buildings, indicating occupant satisfaction is higher in buildings with WELL certification. Although we were unable to pinpoint the reason for higher occupant satisfaction in WELL-certified buildings, the results consistently showed that perceived indoor environmental quality was enhanced across all parameters except for the amount of space.

Proposed simplified methodological approach for designing geopolymer concrete mixtures

The development of geopolymer concrete offers promising prospects for sustainable construction practices due to its reduced environmental impact compared to conventional Portland cement concrete. However, the complexity involved in geopolymer concrete mix design often poses challenges for engineers and practitioners. In response, this study proposes a simplified approach for designing geopolymer concrete mixtures, drawing upon principles from Portland cement concrete mix design standards and recommended molar ratios of oxides involved in geopolymer synthesis. The proposed methodology aims to streamline the mix design process while optimizing key factors such as chemical composition, alkali activation solution, water content, and curing conditions to achieve desired compressive strength and workability. By leveraging commonalities between Portland cement concrete and geopolymer concrete, this approach seeks to facilitate the adoption of geopolymer concrete in practical construction applications. The proposed mix design guidelines have been validated through examples for concrete cured under different conditions, including outdoor and oven curing. Future research should focus on validating the proposed methodology through experimental studies and exploring cost-effective alternatives for alkali activation solutions to enhance the feasibility and scalability of geopolymer concrete production. Overall, the proposed simplified approach holds promise for advancing the utilization of geopolymer concrete as a sustainable alternative in the construction industry.

Analysis and Optimization of Fluid Flow on the Surface of the Prototype Body of Electrical Vehicle Ganesha Diffabilities Using Solidworks Software

Purpose: The aerodynamic aspect is an aspect that takes into account a force caused by the fluid flow shown by the Coefficient of Drag value. This will affect the optimization of performance and energy consumption used. This study aims to modify the standard design of Electrical Ganesha Diffabilities so that a design with a low Coefficient of Drag value considers ergonomic parameters and user comfort to follow the community of people with disabilities. Theoretical Framework: The main theoretical foundation is based on the laws of aerodynamics, which analyze the movement of air around solid objects and its effect on vehicle performance, with a specific emphasis on minimizing drag. The research employs computational fluid dynamics (CFD), a branch of fluid flows. Models and simulations in Solidworks offer a digital environment for improving design aspects to increase aerodynamic efficiency. This theoretical approach focuses on two main objectives: reducing the drag coefficient (CD), which measures resistance caused by shape and surface characteristics, and applying these findings to achieve practical energy savings and enhance vehicle operation specifically designed for individuals with disabilities. The integration of aerodynamic theory and practical application is essential for solving the specific transportation requirements emphasized in the introduction. This alignment with legislation and social objectives aims to provide improved support for the impaired community. Design/Methodology/Approach: This is a numerical method with an R2D2 research model (Reflective, Recursive, Design, and Development) using the 2020 version of Solidworks Software. Solidworks software is known for software that has speed and accuracy in analyzing. Findings: The results of the fluid flow analysis simulation showed that the design of the modified Electrical Ganesha diffabilities vehicle had a Coefficient of Drag value of 0.353 or 35% lower than the standard vehicle value of 0.547. Through expert assessment, the modified design of Electrical Ganesha Diffabilities has received an assessment of 98% with excellent qualifications. Research, Practical &amp; Social implications: The research contributes to the topic of aerodynamic for disability-friendly vehicles, providing a basis for future academic investigations into accessible transportation options. Essentially, the results can immediately impact the development of electric cars that are both more energy-efficient and performance-optimized for those with impairments. This would lead to lower running expenses and improved user-friendliness. From a social perspective, this research emphasizes a dedication to inclusiveness and accessibility, which has the potential to enhance the ability of impaired persons to move around and ultimately enhance their overall well-being. Additionally, it increases awareness among policymakers and manufactures of the significance of incorporating aerodynamic efficiency into the design of assistive devices, hence fostering wider social acceptance and support for this advancement. Originality/Value: The uniqueness and significance of this work stem from its innovative strategy of combining aerodynamic principles with the development of electric cars particularly tailored for those with disabilities-a relatively unexplored field in transportation research. This research examines the E-GADIS vehicle and fills the gap in the current literature on accessible transportation options.