scholarly journals Optimizing the use of acoustic materials in office buildings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdullah AlOmani ◽  
Khaled El-Rayes ◽  
Ayman Altuwaim

AbstractOffice space designers encounter a challenge in identifying the optimal set of noise control materials to improve the acoustic quality while keeping the cost of selected acoustic materials to a minimum. To address this challenge, this paper presents a novel optimization model that provides the capability of minimizing the cost of acoustic materials while satisfying all designer-specified acoustic quality requirements. The model is developed in five main stages that focus on (1) identifying the correlated designer decisions that influence the model objective function; (2) formulating an optimization objective function; (3) identifying the model constraints that are organized into acoustic quality and materials selection constraints; (4) implementing the model using genetic algorithms (GA); and (5) evaluating the performance of the model using an office space design that is under construction to assess and improve the model feasibility and performance. The outcome of the performance evaluation stage illustrates the novel capabilities of the developed model in identifying the optimal selections for the type and area of acoustic material for each surface in the office space that achieve the desired acoustic quality while keeping the cost of selected acoustic materials to a minimum.

2020 ◽  
Vol 4 (02) ◽  
pp. 34-45
Author(s):  
Naufal Dzikri Afifi ◽  
Ika Arum Puspita ◽  
Mohammad Deni Akbar

Shift to The Front II Komplek Sukamukti Banjaran Project is one of the projects implemented by one of the companies engaged in telecommunications. In its implementation, each project including Shift to The Front II Komplek Sukamukti Banjaran has a time limit specified in the contract. Project scheduling is an important role in predicting both the cost and time in a project. Every project should be able to complete the project before or just in the time specified in the contract. Delay in a project can be anticipated by accelerating the duration of completion by using the crashing method with the application of linear programming. Linear programming will help iteration in the calculation of crashing because if linear programming not used, iteration will be repeated. The objective function in this scheduling is to minimize the cost. This study aims to find a trade-off between the costs and the minimum time expected to complete this project. The acceleration of the duration of this study was carried out using the addition of 4 hours of overtime work, 3 hours of overtime work, 2 hours of overtime work, and 1 hour of overtime work. The normal time for this project is 35 days with a service fee of Rp. 52,335,690. From the results of the crashing analysis, the alternative chosen is to add 1 hour of overtime to 34 days with a total service cost of Rp. 52,375,492. This acceleration will affect the entire project because there are 33 different locations worked on Shift to The Front II and if all these locations can be accelerated then the duration of completion of the entire project will be effective


2015 ◽  
Vol 6 (1) ◽  
pp. 50-57
Author(s):  
Rizqa Raaiqa Bintana ◽  
Putri Aisyiyah Rakhma Devi ◽  
Umi Laili Yuhana

The quality of the software can be measured by its return on investment. Factors which may affect the return on investment (ROI) is the tangible factors (such as the cost) dan intangible factors (such as the impact of software to the users or stakeholder). The factor of the software itself are assessed through reviewing, testing, process audit, and performance of software. This paper discusses the consideration of return on investment (ROI) assessment criteria derived from the software and its users. These criteria indicate that the approach may support a rational consideration of all relevant criteria when evaluating software, and shows examples of actual return on investment models. Conducted an analysis of the assessment criteria that affect the return on investment if these criteria have a disproportionate effort that resulted in a return on investment of a software decreased. Index Terms - Assessment criteria, Quality assurance, Return on Investment, Software product


2020 ◽  
Vol 20 (10) ◽  
pp. 1682-1695
Author(s):  
Foziyah Zakir ◽  
Kanchan Kohli ◽  
Farhan J. Ahmad ◽  
Zeenat Iqbal ◽  
Adil Ahmad

Osteoporosis is a progressive bone disease that remains unnoticed until a fracture occurs. It is more predominant in the older age population, particularly in females due to reduced estrogen levels and ultimately limited calcium absorption. The cost burden of treating osteoporotic fractures is too high, therefore, primary focus should be treatment at an early stage. Most of the marketed drugs are available as oral delivery dosage forms. The complications, as well as patient non-compliance, limit the use of oral therapy for prolonged drug delivery. Transdermal delivery systems seem to be a promising approach for the delivery of anti-osteoporotic active moieties. One of the confronting barriers is the passage of drugs through the SC layers followed by penetration to deeper dermal layers. The review focuses on how anti-osteoporotic drugs can be molded through different approaches so that they can be exploited for the skin to systemic delivery. Insights into the various challenges in transdermal delivery and how the novel delivery system can be used to overcome these have also been detailed.


Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 200
Author(s):  
Eric J. Gangloff ◽  
Sierra Spears ◽  
Laura Kouyoumdjian ◽  
Ciara Pettit ◽  
Fabien Aubret

Ectothermic animals living at high elevation often face interacting challenges, including temperature extremes, intense radiation, and hypoxia. While high-elevation specialists have developed strategies to withstand these constraints, the factors preventing downslope migration are not always well understood. As mean temperatures continue to rise and climate patterns become more extreme, such translocation may be a viable conservation strategy for some populations or species, yet the effects of novel conditions, such as relative hyperoxia, have not been well characterised. Our study examines the effect of downslope translocation on ectothermic thermal physiology and performance in Pyrenean rock lizards (Iberolacerta bonnali) from high elevation (2254 m above sea level). Specifically, we tested whether models of organismal performance developed from low-elevation species facing oxygen restriction (e.g., hierarchical mechanisms of thermal limitation hypothesis) can be applied to the opposite scenario, when high-elevation organisms face hyperoxia. Lizards were split into two treatment groups: one group was maintained at a high elevation (2877 m ASL) and the other group was transplanted to low elevation (432 m ASL). In support of hyperoxia representing a constraint, we found that lizards transplanted to the novel oxygen environment of low elevation exhibited decreased thermal preferences and that the thermal performance curve for sprint speed shifted, resulting in lower performance at high body temperatures. While the effects of hypoxia on thermal physiology are well-explored, few studies have examined the effects of hyperoxia in an ecological context. Our study suggests that high-elevation specialists may be hindered in such novel oxygen environments and thus constrained in their capacity for downslope migration.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1279
Author(s):  
Amaya Martínez-Gracia ◽  
Sergio Usón ◽  
Mª Teresa Pintanel ◽  
Javier Uche ◽  
Ángel A. Bayod-Rújula ◽  
...  

A real case study of an energy system based on a Solar Assisted Heat Pump (SAHP) fed by hybrid photovoltaic-thermal solar panels (PVT) and seasonal storage (SS) is presented in this paper. Exergy and exergy cost analyses are proposed as complementary methods for the assessment and better understanding of the efficiency of this cogeneration solar configuration. The system performance takes advantage of storage heat in summer, when the solar resource is high in Spain, and is then later consumed during the cold winter (heating season). The building is devoted to social housing, and it is currently under construction. The assessment is based on simulations developed using TRNSYS, a dynamic simulation software for energy systems. Results show that the unit exergy cost of the solar field is around 6. The cost of the seasonal storage is higher, about 13, and its formation is affected both by its own irreversibility and by the irreversibility of the PVT solar field. The cost of the heat delivered by the heat pump is around 15, being affected by all the upstream units and even by the grid. Besides, the analysis points out strategies for improving the system efficiency, such as increasing the size of the storage tank or improving the control strategy of the boiler.


2015 ◽  
Vol 785 ◽  
pp. 495-499
Author(s):  
Siti Amely Jumaat ◽  
Ismail Musirin

The paper presents a comparison of performance Static Var Compensator (SVC) and Thyristor Controlled Series Compensator (TCSC) with objective function to minimize the transmission loss, improve the voltage and monitoring the cost of installation. Simulation performed on standard IEEE 30-Bus RTS and indicated that EPSO a feasible to achieve the objective function.


Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  

This paper presents the design, analysis and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees of freedom in movement and flexible design. However to fully take advantage of these properties a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable and power routing systems and increased design difficulty. Here we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture and simulations of TT-3, the first untethered, fully actuated cable-driven six-bar tensegrity spherical robot ever built and tested for mobility. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system’s behavior and performance.


BIOMATH ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 2106147
Author(s):  
Debkumar Pal ◽  
D Ghosh ◽  
P K Santra ◽  
G S Mahapatra

This paper presents the current situation and how to minimize its effect in India through a mathematical model of infectious Coronavirus disease (COVID-19). This model consists of six compartments to population classes consisting of susceptible, exposed, home quarantined, government quarantined, infected individuals in treatment, and recovered class. The basic reproduction number is calculated, and the stabilities of the proposed model at the disease-free equilibrium and endemic equilibrium are observed. The next crucial treatment control of the Covid-19 epidemic model is presented in India's situation. An objective function is considered by incorporating the optimal infected individuals and the cost of necessary treatment. Finally, optimal control is achieved that minimizes our anticipated objective function. Numerical observations are presented utilizing MATLAB software to demonstrate the consistency of present-day representation from a realistic standpoint.


Author(s):  
Arash Farahani ◽  
Peter Childs

Strip seals are used in gas turbine engines between two static elements or between components which do not move relative to each other, such as Nozzle Guide Vanes (NGVs). The key role of a strip seal between NGV segments is sealing between the flow through the main stream annulus and the internal air system, a further purpose is to limit the inter-segmental movements. In general the shape of the strip seal is a rectangular strip that fits into two slots in adjacent components. The minimum clearance required for static strip seals must be found by accounting for thermal expansion, misalignment, and application, to allow correct fitment of the strip seals. Any increase in leakage raises the cost due to an increase in the cooling air use, which is linked to specific fuel consumption, and it can also alter gas flow paths and performance. The narrow path within the seal assembly, especially the height has the most significant affect on leakage. The height range of the narrow path studied in this paper is 0.01–0.06 mm. The behaviour of the flow passing through the narrow path has been studied using CFD modelling and measurements in a bespoke rig. The CFD and experimental results show that normalized leakage flow increases with pressure ratio before reaching a maximum. The main aim of this paper is to provide new experimental data to verify the CFD modelling for static strip seals. The typical flow characteristics validated by CFD modelling and experiments can be used to predict the flow behaviour for future static strip seal designs.


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