A Practical Method for Optimum Seismic Design of Friction Wall Dampers

Friction control systems have been widely used as one of the efficient and cost effective solutions to control structural damage during strong earthquakes. However, the height-wise distribution of slip loads can significantly affect the seismic performance of the strengthened frames. In this study, a practical design methodology is developed for more efficient design of friction wall dampers by performing extensive nonlinear dynamic analyses on 3-, 5-, 10-, 15-, and 20-story RC frames subjected to seven spectrum-compatible design earthquakes and five different slip load distribution patterns. The results show that a uniform cumulative distribution can provide considerably higher energy dissipation capacity than the commonly used uniform slip load pattern. It is also proved that for a set of design earthquakes, there is an optimum range for slip loads that is a function of number of stories. Based on the results of this study, an empirical equation is proposed to calculate a more efficient slip load distribution of friction wall dampers for practical applications. The efficiency of the proposed method is demonstrated through several design examples.

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Estimation of the Seismic Damage Potential of RC Frames Using Seismic Parameters

10.21203/rs.3.rs-1200666/v1 ◽

2022 ◽

Author(s):

Ali Massumi ◽

Maryam Rahmati Selkisari

Keyword(s):

Structural Damage ◽

Fundamental Period ◽

Regression Equations ◽

Mathematical Methods ◽

Damage Potential ◽

Seismic Parameters ◽

Rc Frames ◽

Dynamic Analyses ◽

Nonlinear Dynamic Analyses ◽

Far Fault

Abstract Variation of the fundamental period is regarded as one of the methods to assess the damage of the structures under earthquakes. The inter-relationship among seismic parameters and variation of the fundamental period can identify the potential structural damage of an earthquake. For this purpose, the present paper aimed to study the relations among main seismic parameters, incorporating a variety of information about ground motion and variation of fundamental period. Three RC frames were analyzed under far-fault earthquake records by nonlinear dynamic analyses and mathematical methods applied to assay the correlation between seismic parameters and variation of fundamental period. Based on the results, high correlations were observed between some seismic parameters and variation of fundamental period. Further, based on regression equations, new parameters with a very strong correlation with variations of fundamental periods were achieved, which can be regarded as appropriate indices to estimate the potential structural damage of an earthquake.

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Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

Sustainability ◽

10.3390/su13158421 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8421

Author(s):

Yuan Gao ◽

Jiandong Huang ◽

Meng Li ◽

Zhongran Dai ◽

Rongli Jiang ◽

...

Keyword(s):

Structural Analysis ◽

High Efficiency ◽

Low Cost ◽

Chemical Activation ◽

Cost Effective ◽

Coal Gangue ◽

Order Kinetic ◽

Practical Applications ◽

Detailed Structural Analysis ◽

Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

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Efficient Design of Energy Disaggregation Model with BERT-NILM Trained by AdaX Optimization Method for Smart Grid

Energies ◽

10.3390/en14154649 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4649

Author(s):

İsmail Hakkı ÇAVDAR ◽

Vahit FERYAD

Keyword(s):

Smart Grids ◽

Energy Demand ◽

Optimization Technique ◽

Cost Effective ◽

Optimization Method ◽

Long Term Memory ◽

Successful Implementation ◽

Efficient Design ◽

Energy Disaggregation ◽

Load Monitoring

One of the basic conditions for the successful implementation of energy demand-side management (EDM) in smart grids is the monitoring of different loads with an electrical load monitoring system. Energy and sustainability concerns present a multitude of issues that can be addressed using approaches of data mining and machine learning. However, resolving such problems due to the lack of publicly available datasets is cumbersome. In this study, we first designed an efficient energy disaggregation (ED) model and evaluated it on the basis of publicly available benchmark data from the Residential Energy Disaggregation Dataset (REDD), and then we aimed to advance ED research in smart grids using the Turkey Electrical Appliances Dataset (TEAD) containing household electricity usage data. In addition, the TEAD was evaluated using the proposed ED model tested with benchmark REDD data. The Internet of things (IoT) architecture with sensors and Node-Red software installations were established to collect data in the research. In the context of smart metering, a nonintrusive load monitoring (NILM) model was designed to classify household appliances according to TEAD data. A highly accurate supervised ED is introduced, which was designed to raise awareness to customers and generate feedback by demand without the need for smart sensors. It is also cost-effective, maintainable, and easy to install, it does not require much space, and it can be trained to monitor multiple devices. We propose an efficient BERT-NILM tuned by new adaptive gradient descent with exponential long-term memory (Adax), using a deep learning (DL) architecture based on bidirectional encoder representations from transformers (BERT). In this paper, an improved training function was designed specifically for tuning of NILM neural networks. We adapted the Adax optimization technique to the ED field and learned the sequence-to-sequence patterns. With the updated training function, BERT-NILM outperformed state-of-the-art adaptive moment estimation (Adam) optimization across various metrics on REDD datasets; lastly, we evaluated the TEAD dataset using BERT-NILM training.

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Multivariate empirical mode decomposition–based structural damage localization using limited sensors

Journal of Vibration and Control ◽

10.1177/10775463211006965 ◽

2021 ◽

pp. 107754632110069

Author(s):

Sandeep Sony ◽

Ayan Sadhu

Keyword(s):

Empirical Mode Decomposition ◽

Structural Damage ◽

Cost Effective ◽

Threshold Value ◽

Damage Localization ◽

Time Frequency ◽

Multivariate Empirical Mode Decomposition ◽

Percentage Difference ◽

Mode Decomposition

In this article, multivariate empirical mode decomposition is proposed for damage localization in structures using limited measurements. Multivariate empirical mode decomposition is first used to decompose the acceleration responses into their mono-component modal responses. The major contributing modal responses are then used to evaluate the modal energy for the respective modes. A damage localization feature is proposed by calculating the percentage difference in the modal energies of damaged and undamaged structures, followed by the determination of the threshold value of the feature. The feature of the specific sensor location exceeding the threshold value is finally used to identify the location of structural damage. The proposed method is validated using a suite of numerical and full-scale studies. The validation is further explored using various limited measurement cases for evaluating the feasibility of using a fewer number of sensors to enable cost-effective structural health monitoring. The results show the capability of the proposed method in identifying as minimal as 2% change in global modal parameters of structures, outperforming the existing time–frequency methods to delineate such minor global damage.

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Doing More With Less: Pragmatic Implementation of Vancomycin Area-Under-the-Curve (AUC) Monitoring

Journal of Pharmacy Practice ◽

10.1177/08971900211027271 ◽

2021 ◽

pp. 089719002110272

Author(s):

Joanne Huang ◽

Jeannie D. Chan ◽

Thu Nguyen ◽

Rupali Jain ◽

Zahra Kassamali Escobar

Keyword(s):

Quality Improvement ◽

High Risk ◽

Therapeutic Drug Monitoring ◽

Paradigm Shift ◽

Area Under The Curve ◽

Cost Effective ◽

Practical Method ◽

Therapeutic Drug ◽

Short Term ◽

Quality Improvement Process

Universal area-under-the-curve (AUC) guided vancomycin therapeutic drug monitoring (TDM) is resource-intensive, cost-prohibitive, and presents a paradigm shift that leaves institutions with the quandary of defining the preferred and most practical method for TDM. We report a step-by-step quality improvement process using 4 plan-do-study-act (PDSA) cycles to provide a framework for development of a hybrid model of trough and AUC-based vancomycin monitoring. We found trough-based monitoring a pragmatic strategy as a first-tier approach when anticipated use is short-term. AUC-guided monitoring was most impactful and cost-effective when reserved for patients with high-risk for nephrotoxicity. We encourage others to consider quality improvement tools to locally adopt AUC-based monitoring.

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Seismic Response of RC Frames with a Soft First Story Retrofitted with Hysteretic Dampers under Near-Fault Earthquakes

Applied Sciences ◽

10.3390/app11031290 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1290

Author(s):

Santiago Mota-Páez ◽

David Escolano-Margarit ◽

Amadeo Benavent-Climent

Keyword(s):

Cost Effective ◽

Far Field ◽

Soft Story ◽

Near Fault ◽

Rc Frames ◽

Story Drift ◽

Number Of Cycles ◽

Rc Frame Structures ◽

Near Fault Earthquakes ◽

Hysteretic Dampers

Reinforced concrete (RC) frame structures with open first stories and masonry infill walls at the upper stories are very common in seismic areas. Under strong earthquakes, most of the energy dissipation demand imposed by the earthquake concentrates in the first story, and this eventually leads the building to collapse. A very efficient and cost-effective solution for the seismic upgrading of this type of structure consists of installing hysteretic dampers in the first story. This paper investigates the response of RC soft-story frames retrofitted with hysteretic dampers subjected to near-fault ground motions in terms of maximum displacements and lateral seismic forces and compares them with those obtained by far-field earthquakes. It is found that for similar levels of total seismic input energy, the maximum displacements in the first story caused by near-fault earthquakes are about 1.3 times larger than those under far-field earthquakes, while the maximum inter-story drift in the upper stories and the distribution and values of the lateral forces are scarcely affected. It is concluded that the maximum displacements can be easily predicted from the energy balance of the structure by using appropriate values for the parameter that reflects the influence of the impulsivity of the ground motion: the so-called equivalent number of cycles.

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Enhanced Thermoelectric Performance of n-Type Bi2Se3 Nanosheets through Sn Doping

Nanomaterials ◽

10.3390/nano11071827 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1827

Author(s):

Mengyao Li ◽

Yu Zhang ◽

Ting Zhang ◽

Yong Zuo ◽

Ke Xiao ◽

...

Keyword(s):

Figure Of Merit ◽

Cost Effective ◽

Low Grade ◽

Hot Press ◽

Processing Technologies ◽

Sn Doping ◽

Practical Applications ◽

Alternative Materials ◽

The Cost ◽

Low Grade Heat

The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.

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Probabilistic finite element analysis in heat transfer to a nuclear fuel rod bumper support

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406042690425 ◽

2004 ◽

Vol 218 (12) ◽

pp. 1499-1505

Author(s):

Rama Subba Reddy Gorla

Keyword(s):

Heat Transfer ◽

Finite Element ◽

Nuclear Fuel ◽

Cost Effective ◽

Distribution Functions ◽

Cumulative Distribution ◽

Element Analysis ◽

Transfer Rates ◽

Fuel Rod ◽

Design Variables

Heat transfer from a nuclear fuel rod bumper support was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for overall heat transfer rates due to the thermodynamic random variables. These results can be used to identify quickly the most critical design variables in order to optimize the design and to make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in heat transfer and to the identification of both the most critical measurements and the parameters.

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Autonomous Control and Transportation of Underslung Load with Single and Dual Lift Helicopter Systems

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4053186 ◽

2021 ◽

Author(s):

Kuldeep K Dhiman ◽

Mangal Kothari ◽

Dr. Abhishek

Keyword(s):

Load Distribution ◽

Compressive Load ◽

Force Sensor ◽

Outdoor Environment ◽

Measurement Unit ◽

Control Law ◽

Autonomous Flight ◽

Practical Applications ◽

Load Swing ◽

Load Transportation

Abstract This paper discusses the development of a single lift and dual-lift helicopter underslung load transportation system for practical applications. A control law is developed to damp the load swing and stabilize the oscillation while performing the transportation task. For the dual-lift system, the load transportation is achieved by using a load distribution controller, developed for this purpose, to maintain equal load distribution among the vehicles. The load damping and load distribution controllers require accurate measurement of load states, which is achieved through the design and development of innovative, simple, and lightweight sensors units namely, Load Tension Measurement Unit (LTMU) and Load Swing Measurement Unit (LSMU). LTMU sensor consists of a unique design that utilizes a flexi-force sensor, capable of measuring compressive load, for measurement of cable tension. The cable inclination in the longitudinal and lateral directions is measured by the LSMU sensor. These units are integrated with the helicopter autopilot for autonomous flight. The performance of the developed system is experimentally validated in the outdoor environment with single and dual-lift systems.

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Modelling of new generation plasma optical devices

Nukleonika ◽

10.1515/nuka-2016-0035 ◽

2016 ◽

Vol 61 (2) ◽

pp. 207-212 ◽

Cited By ~ 2

Author(s):

Irina V. Litovko ◽

Alexy A. Goncharov ◽

Andrew N. Dobrovolskiy ◽

Lily V. Naiko ◽

Irina V. Naiko

Keyword(s):

Low Cost ◽

Rocket Engine ◽

Cost Effective ◽

Optical Devices ◽

High Tech ◽

Practical Applications ◽

Plasma Accelerators ◽

New Generation ◽

Closed Electron ◽

Positive Space

Abstract The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

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