Integration of Lightweight Foam Concrete Roof, Moving-Air-Cavity, and Solar-Powered Fans for Attic Temperature Reduction

This paper presents a novel cool roof technology system that promotes both passive and active cooling methods in reducing the attic temperature of the building. The project aimed to evaluate the effect of various roof model designs on the heating load to establish the capacity of a cooling roof system by maintaining the thermal comfort level for occupants in the buildings. There are four main components in constructing the cool roof models: 1) metal deck roof, 2) lightweight foam concrete roof, 3) moving-air-cavity (MAC) ventilation, and 4) solar-powered fan. Four small-scale cool roof models were built to evaluate the performance of each cool roof design. The performances of the roof surface and attic temperatures of each designed cool roof models were compared with the conventional metal deck roof. The roof models were conducted indoors by using halogen spotlights. The result of the Roof Design IV with the integration of lightweight foam concrete, MAC, and solar-powered fans has effectively reduced the attic temperature by 6.0°C compared with the normal roof model (Roof Design I). As a result, this integrated cool roof design comprises the ability to enhance the comfortability of occupants toward long-term sustainable development with the utilization of renewable energy to protect the natural environment.

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Rainwater Harvesting System Integrated With Sensors for Attic Temperature Reduction

Frontiers in Built Environment ◽

10.3389/fbuil.2021.647594 ◽

2021 ◽

Vol 7 ◽

Author(s):

Ming Chian Yew ◽

Song Wei Wong ◽

Ming Kun Yew ◽

Lip Huat Saw

Keyword(s):

Rainwater Harvesting ◽

Comfort Level ◽

Solar Irradiation ◽

Small Scale ◽

Airflow Rate ◽

Halogen Lamp ◽

Roof System ◽

Technology System ◽

Cool Roof ◽

Solar Powered

This cool roof system focuses on utilization of rainwater harvesting systems by integrating the smart sensor to cool the roof and attic temperatures for the improvement of comfort level of building occupants. An ideal cool roof technology system is basically made up of these three components: (1) moving-air-cavity (MAC) ventilation, (2) solar-powered fan and (3) rainwater harvesting system. These three main components integrate to perform and control the cool roof system. Four small-scale cool roof models were designed and constructed to inspect the performance of the rooftop and attic temperatures. The experimental work was carried out indoors by employing the halogen lamp as the replacement for solar irradiation, while the ambient temperature is monitored to be around 29.8 °C throughout the test. The temperatures of the rooftop surface, MAC aluminum tube, and attic region were measured by K-type thermocouples to evaluate the performance of the cool roof designs. The solar-powered fans were incorporated into the MAC, which accelerated the airflow rate within the cavity and rejected the hot air out before transferring it to the attic region. Meanwhile, an innovative rainwater harvesting system was executed to cool the rooftop temperature rapidly by reducing the rate of heat transfer to the attic region. The result of this inventive cool roof system (Design Z) has successfully reduced the attic temperature by 10.8 °C compared to the normal metal deck roof model (Design W). The findings of the project revealed that the integrated cool roofing technology system comprises the ability to enhance the comfortability of building occupants toward a long-term sustainable development for a better world.

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Structural Behavior of Precast Lightweight Foam Concrete Sandwich Panel with Double Shear Truss Connectors under Flexural Load

ISRN Civil Engineering ◽

10.1155/2014/317941 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 9

Author(s):

Noridah Mohamad ◽

A. I. Khalil ◽

A. A. Abdul Samad ◽

W. I. Goh

Keyword(s):

Compressive Strength ◽

Sandwich Panel ◽

Crack Pattern ◽

Structural Behavior ◽

Foam Concrete ◽

Structural Behaviour ◽

Shear Connectors ◽

Double Shear ◽

Partially Composite ◽

Lightweight Foam

This paper presents the structural behaviour of precast lightweight foam concrete sandwich panel (PFLP) under flexure, studied experimentally and theoretically. Four (4) full scale specimens with a double shear steel connector of 6 mm diameter and steel reinforcement of 9 mm diameter were cast and tested. The panel’s structural behavior was studied in the context of its ultimate flexure load, crack pattern, load-deflection profile, and efficiency of shear connectors. Results showed that the ultimate flexure load obtained from the experiment is influenced by the panel’s compressive strength and thickness. The crack pattern recorded in each panel showed the emergence of initial cracks at the midspan which later spread toward the left and right zones of the slab. The theoretical ultimate load for fully composite and noncomposite panels was obtained from the classical equations. All panel specimens were found to behave in a partially composite manner. Panels PLFP-3 and PLFP-4 with higher compressive strength and total thickness managed to obtain a higher degree of compositeness which is 30 and 32.6 percent, respectively.

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Small Scale Integrated Sustainable Roof Design (Case Study in Surakarta City)

Civil Engineering and Architecture ◽

10.13189/cea.2020.080413 ◽

2020 ◽

Vol 8 (4) ◽

pp. 500-506

Author(s):

Purwanti Sri Pudyastuti ◽

Findria Kalista ◽

Gurawan Djati Wibowo ◽

Hermono S Budinetro

Keyword(s):

Small Scale ◽

Design Case ◽

Design Case Study ◽

Roof Design

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Design and Performance of Small Scale Solar Powered Water Desalination Systems, Utilizing Reverse Osmosis

Journal of Solar Energy Engineering ◽

10.1115/1.1330542 ◽

2000 ◽

Vol 122 (4) ◽

pp. 170-175 ◽

Cited By ~ 7

Author(s):

K. B. Franc¸a ◽

H. M. Laborde ◽

H. Neff

Keyword(s):

High Pressure ◽

Energy Consumption ◽

Feed Solution ◽

Water Desalination ◽

Small Scale ◽

Feed Water ◽

High Pressure Pump ◽

And Performance ◽

Solar Powered ◽

Power Needs

A small scale solar powered desalination system has been designed, analyzed, and optimized with regard to power needs and energy consumption. Both quantities scale linearly with the concentration of the total dissolved salt concentration (TDS) in the feed solution. The desalination of brackish water at a TDS value of 3,000 ppm requires an energy of approximately 1.5 kWh/m3. For seawater at a TDS value of 34,000 ppm, this value increases to 9.5 kWh/m3. The selected type of membrane, the system design, and, in particular, the efficiency of the high pressure pump crucially affect energy consumption. The desalination cost also has been estimated for a small scale system that linearly scale with the TDS value of the feed water. [S0199-6231(00)00104-0]

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Experimental Testing and Numerical Modeling of Small-Scale Boat With Drag-Reducing Air-Cavity System

10.1115/fedsm2021-62556 ◽

2021 ◽

Author(s):

Jeffrey M. Collins ◽

Phillip R. Whitworth ◽

Konstantin I. Matveev

Keyword(s):

Adaptive Mesh Refinement ◽

Experimental Testing ◽

Hydrodynamic Performance ◽

Small Scale ◽

Video Monitor ◽

Data Logger ◽

Time Step ◽

Experimental Conditions ◽

Air Cavity ◽

Air Supply

Abstract Hydrodynamic performance of ships can be greatly improved by the formation of air cavities under ship bottom with the purpose to decrease water friction on the hull surface. The air-cavity ships using this type of drag reduction are usually designed for and typically effective only in a relatively narrow range of speeds and hull attitudes and sufficient rates of air supply to the cavity. To investigate the behavior of a small-scale air-cavity boat operating under both favorable and detrimental loading and speed conditions, a remotely controlled model hull was equipped with a data acquisition system, video camera and onboard sensors to measure air-cavity characteristics, air supply rate and the boat speed, thrust and trim in operations on open-water reservoirs. These measurements were captured by a data logger and also wirelessly transmitted to a ground station and video monitor. The experimental air-cavity boat was tested in a range of speeds corresponding to length Froude numbers between 0.17 and 0.5 under three loading conditions, resulting in near zero trim and significant bow-up and bow-down trim angles at rest. Reduced cavity size and significantly increased drag occurred when operating at higher speeds, especially in the bow-up trim condition. The other objective of this study was to determine whether computational fluid dynamics simulations can adequately capture the recorded behavior of the boat and air cavity. A computational software Star-CCM+ was utilized with the VOF method employed for multi-phase flow, RANS approach for turbulence modeling, and economical mesh settings with refinements in the cavity region and near free surface. Upon conducting the mesh verification study, several experimental conditions were simulated, and approximate agreement with measured test data was found. Adaptive mesh refinement and time step controls were also applied to compare results with those obtained on the user-generated mesh. Adaptive controls improved resolution of complex shedding patterns from the air cavity but had little impact on overall results. The presented here experimental approach and obtained results indicate that both outdoor experimentation and computationally inexpensive modeling can be used in the process of developing air-cavity systems for ship hulls.

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Small-scale solar-powered groundwater desalination

Integrated Water Resources Management in Water-scarce Regions: Water Harvesting, Groundwater Desalination and Water Reuse in Namibia ◽

10.2166/9781780407913_172 ◽

2018 ◽

pp. 171-223

Keyword(s):

Small Scale ◽

Solar Powered

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Cost-Effectiveness of Solar-Powered LED Reading Lamps in Burkina Faso

Advances in Library and Information Science - Rural Community Libraries in Africa ◽

10.4018/978-1-4666-5043-5.ch011 ◽

2013 ◽

pp. 203-221

Keyword(s):

Cost Effectiveness ◽

Burkina Faso ◽

Small Scale ◽

Small Community ◽

Reading Habits ◽

Education Interventions ◽

Solar Powered ◽

Reading Test Scores ◽

One Year ◽

6Th Graders

A small-scale project to induce more reading among 5th and 6th graders in rural Burkina Faso by providing them with solar-powered LED lamps indeed increased reading for students in villages without preexisting libraries, but did not affect reading capabilities. The research aimed to establish the magnitude of effects after one year when 10-14 year-olds in rural African villages with small community libraries were given solar-powered lamps for night reading. The effects measured were reading habits (how much did students read?) and reading capabilities (how well could students read and comprehend what they read?). Once village effects were controlled, the lamps had statistically significant effects on reading habits for students in villages without preexisting libraries. The effect sizes were modest, ranging from .20 to .25. There were no effects on reading test scores. A cost-effectiveness metric to use for comparing with other studies of education interventions then is that expenditure of $1 per student on a solar-powered LED reading lamp distribution program generated about a 1% increase in reading, with no apparent effect on reading capabilities.

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Agile Scrum Issues at Large-Scale Distributed Projects

10.4018/978-1-6684-3702-5.ch019 ◽

2022 ◽

pp. 388-398

Author(s):

Ayesha Khalid ◽

Shariq Aziz Butt ◽

Tauseef Jamal ◽

Saikat Gochhait

Keyword(s):

Software Development ◽

Large Scale ◽

Software Industry ◽

Small Scale ◽

Project Organization ◽

Distinctive Features ◽

Main Components ◽

Change Requests ◽

Agile Model ◽

Large Scale Project

The agile model is a very vast and popular model in use in the software industry currently. It changes the way software is developed. It was introduced in 2001 to overcome deficiencies of software development in a workshop arranged by researchers and practitioners who were involved with the agile concept. They introduced the complete agile manifesto. The agile model has main components that make it more viable for use in well-organized software development. One of these is scrum methodology. The reason for the agile-scrum popularity is its use for small-scale projects, making small teams and allows change requests at any stage of a project from the client. It works for client satisfaction. Instead of so much popularity and distinctive features, agile-scrum also has some limitations when used for large scale projects development that makes it less efficient for development. This article discusses the agile-scrum methodology and its limitations when using for large-scale project organization.

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Mapping the physical and chemical properties of the planetary nebula NGC 3242

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312011866 ◽

2011 ◽

Vol 7 (S283) ◽

pp. 448-449

Author(s):

Hektor Monteiro ◽

Denise Gonçalves ◽

Marcelo Leal-Ferreira ◽

Romano Corradi ◽

Sebastian Sánchez

Keyword(s):

Planetary Nebula ◽

Three Dimensional ◽

Chemical Properties ◽

Small Scale ◽

Chemical Abundances ◽

Electronic Density ◽

Spatially Resolved ◽

Integral Field Spectroscopy ◽

Main Components ◽

Physical And Chemical

AbstractWe present optical integral field spectroscopy analysis of the main components, with the exception of the halo, as well as of the detected small-scale structures of the planetary nebulae NGC 3242. The observations were obtained with the VIMOS instrument attached to VLT-UT3. Spatially resolved maps of the electronic density (Ne), temperatures (Te) and chemical abundances, i.e., in a pixel to pixel fashion of the small and large-scales structures of this planetary nebula are determined in this work. These diagnostic and abundance maps represent important constraints for future detailed three dimensional photoionization modeling of the nebula, as well as providing important information on biases introduced by traditional slit observations.

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