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Kosmos
Astronomia Astrofizyka
Inne

Kultura
Sztuka dawna i współczesna, muzea i kolekcje

Metoda
Metodologia nauk, Matematyka, Filozofia, Miary i wagi, Pomiary

Materia
Substancje, reakcje, energia
Fizyka, chemia i inżynieria materiałowa

Człowiek
Antropologia kulturowa Socjologia Psychologia Zdrowie i medycyna

Wizje
Przewidywania Kosmologia Religie Ideologia Polityka

Ziemia
Geologia, geofizyka, geochemia, środowisko przyrodnicze

Życie
Biologia, biologia molekularna i genetyka

Cyberprzestrzeń
Technologia cyberprzestrzeni, cyberkultura, media i komunikacja

Działalność
Wiadomości | Gospodarka, biznes, zarządzanie, ekonomia

Technologie
Budownictwo, energetyka, transport, wytwarzanie, technologie informacyjne

American Journal of Engineering and Applied Sciences

For underwater communication, sound signals are used in contrast to RF. Recent development in wireless sensor network for underwater applications such as ocean exploration, marine aquaculture, sea animal tracking and so on have motivated the researchers and developers to understand the properties of sound signal within water in details. This study presents work on design and development of a simulation platform which can study the properties of the sound signal in virtual in-water situation. The platform is called functional, because this is a dedicated platform which only deals with the sound signal. The scope of the development includes software development principles and methods, review of signal-specific scientific principles and integration of the principles and laws into the software system via object-oriented strategy considering existing data structures and testing and validation of the platform with exemplar results. The functional platform also incorporates modulation techniques, the type of technology systems to be used and radiation pattern of the signal under the water. The test results show that that functional platform can work for simulation study of radiation pattern of sound signal in underwater scenario.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.327.337 2014/09/12 - 14:15

State wide variant topographic features in North Carolina attract the hydro-climatologist. There is none modeling study found that predict future Land Cover Land Use (LCLU) change for whole North Carolina. In this study, satellite-derived land cover maps of year 1992, 2001 and 2006 of North Carolina were integrated within the framework of the Markov-Cellular Automata (Markov-CA) model which combines the Markov chain and Cellular Automata (CA) techniques. A Multi-Criteria Evaluation (MCE) was used to produce suitability future images. The Markov Chain and MCE analyses provided transition probability area and suitable images, respectively which were then dynamically adjusted through the Multi-Objective Land Allocation and CA spatial filter. Two stages of validation procedures were adopted in this study: 1. The Relative Operating Characteristics was used to validate suitability images and 2. The Kappa index of agreement was used to validate the overall LCLU changed simulated map. LCLU prediction of North Carolina for year 2030 shows 20% increase of built up land, 17% decrease of forest land while comparing that with year 1992. About 7% agricultural land was found to decrease in 2030 when compared with 2001 data. No significant changes were found for water body and other land category coverage. Much of the built-up land (urban expansion) was found to be in the southern, mid and mid-eastern portion of North Carolina. Loss of forest area was predicted mostly in western and mid-western part.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.295.306 2014/09/10 - 03:22

Fused Deposition Modelling (FDM), a renowned Rapid Prototyping (RP) process, has been successfully implemented in several industries to fabricate concept models and prototypes for rapid manufacturing. This study furnishes terse notes about the material damping properties of FDM made ULTEM samples considering the effect of FDM process parameters. Dynamic Mechanical Analysis (DMA) is carried out using DMA 2980 equipment to study the dynamic response of the FDM material subjected to single cantilever loading under periodic stress. Three FDM process parameters namely Build Style, Raster Width and Raster Angle were contemplated. ULTEM parts are fabricated using solid normal build style and three values each of raster width and raster angle. DMA is performed with temperature sweep at three different fixed frequencies of 1, 50 and 100 Hz. Results were obtained for dynamic properties such as Maximum Storage Modulus, Maximum Loss Modulus, Maximum Tan Delta and Maximum Complex Viscosity. The present work discusses the effect of increasing the frequencies and temperature on FDM made ULTEM samples using different FDM process parameters.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.307.315 2014/09/10 - 03:22

State wide variant topographic features in North Carolina attract the hydro-climatologist. There is none modeling study found that predict future Land Cover Land Use (LCLU) change for whole North Carolina. In this study, satellite-derived land cover maps of year 1992, 2001 and 2006 of North Carolina were integrated within the framework of the Markov-Cellular Automata (Markov-CA) model which combines the Markov chain and Cellular Automata (CA) techniques. A Multi-Criteria Evaluation (MCE) was used to produce suitability future images. The Markov Chain and MCE analyses provided transition probability area and suitable images, respectively which were then dynamically adjusted through the Multi-Objective Land Allocation and CA spatial filter. Two stages of validation procedures were adopted in this study: 1. The Relative Operating Characteristics was used to validate suitability images and 2. The Kappa index of agreement was used to validate the overall LCLU changed simulated map. LCLU prediction of North Carolina for year 2030 shows 20% increase of built up land, 17% decrease of forest land while comparing that with year 1992. About 7% agricultural land was found to decrease in 2030 when compared with 2001 data. No significant changes were found for water body and other land category coverage. Much of the built-up land (urban expansion) was found to be in the southern, mid and mid-eastern portion of North Carolina. Loss of forest area was predicted mostly in western and mid-western part.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.292.303 2014/08/23 - 23:32

Fused Deposition Modelling (FDM), a renowned Rapid Prototyping (RP) process, has been successfully implemented in several industries to fabricate concept models and prototypes for rapid manufacturing. This study furnishes terse notes about the material damping properties of FDM made ULTEM samples considering the effect of FDM process parameters. Dynamic Mechanical Analysis (DMA) is carried out using DMA 2980 equipment to study the dynamic response of the FDM material subjected to single cantilever loading under periodic stress. Three FDM process parameters namely Build Style, Raster Width and Raster Angle were contemplated. ULTEM parts are fabricated using solid normal build style and three values each of raster width and raster angle. DMA is performed with temperature sweep at three different fixed frequencies of 1, 50 and 100 Hz. Results were obtained for dynamic properties such as Maximum Storage Modulus, Maximum Loss Modulus, Maximum Tan Delta and Maximum Complex Viscosity. The present work discusses the effect of increasing the frequencies and temperature on FDM made ULTEM samples using different FDM process parameters.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.304.312 2014/08/22 - 06:32

Efficiency is becoming a pivotal aspect in each manufacturing system and scheduling plays a crucial role in sustaining it. The applicability of distributed computing to coordinate and execute jobs has been investigated in the past literature. Moreover, it is significant that even for sensitive industrial systems the only criterion of allocating jobs to appropriate machines is the FIFO policy. On the other flip, many researchers are of the opinion that the main reason behind failing to provide fairness in distributed systems is considering the only criterion of time stamp to judge upon and form the queue of jobs with the aim of allocating those jobs to the machines. In order to increase the efficiency of sensitive industrial system, this study takes into consideration of three criteria of each job including priority, time action and time stamp. The methodology adopted by this study is definition of job scheduler and positioning jobs in temporary queue and sorting via developing bubble sort. In sorting algorithm criterion of priority, time action should be considered besides time stamp to recognize the tense jobs for processing earlier. To evaluate this algorithm first a numerical test case (simulation) is programmed and then the case study performing in order to optimize efficiency of applying this method in real manufacturing system. Eventually the results of this study provided evidence on that the rate of efficiency is increased.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.282.291 2014/07/09 - 22:41

This study highlighted on managing the waste elimination database in lean manufacturing of the case study company. An application for managing the waste elimination database in lean manufacturing to improve the visual indicators and enhance the problem solving capabilities of the employees in the organization is introduced as the basic success factors to drive the process of continuous improvement culture forward. Ineffective database systems within the organization have caused the inaccurate, redundancy and inconsistency of data. Lean implementations are not successful because there is a lack of communication and involvement of all levels of employees. The study attempts to design an application in a personal database system to the employees at Lean department to keep track of the waste elimination database for analysis and evaluation purpose. Likewise, it’s also examined the employees’ problem solving capacity in waste eliminating project. Application in Microsoft Access is considered new in the case study company. The problems that faced are such as the human factors such as the fearful in changing and accepting IT systems and procedures. Application in Microsoft Access is considered new in the case study company. The employees in Lean department can easily keep track on the improvement projects and the management can monitor on the improvement task and problem solving capabilities of the employees. The visual indicators are improved because meaningful chart and reports are generated for visual and filling purpose. Besides, implementing the problem solving cycle in the designed application to improve the problem solving activities which is also an important element in creating continuous improvement culture. As the many factors such as human factors and skills in using the database application are affected the effectiveness of the designed application. The cost saving value after implementation the database application is difficult to obtain as some study subject are difficult to measure in term of cost.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.271.281 2014/07/09 - 22:41

Recent years have witnessed a great deal of interest from both scientific and academic communities in the field of flexible electronic systems. Most flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today’s network oriented society. On the other hand, High Impedance Surfaces have become very popular in the design of contemporary antenna and micro-wave devices due to their wide range of applications derived from their unique electromagnetic properties which significantly enhance the performance of antennas and RF systems. Accordingly, the integration of HIS structures within flexible wireless systems is very beneficial in this growing field of research. In this paper, a systematic review of flexible HIS structures reported in the literature is conducted, which provides the reader with a thorough description and a complete list of state of the art designs intended for flexible wireless systems.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.266.270 2014/07/09 - 22:41

This study highlighted on managing the waste elimination database in lean manufacturing of the case study company. An application for managing the waste elimination database in lean manufacturing to improve the visual indicators and enhance the problem solving capabilities of the employees in the organization is introduced as the basic success factors to drive the process of continuous improvement culture forward. Ineffective database systems within the organization have caused the inaccurate, redundancy and inconsistency of data. Lean implementations are not successful because there is a lack of communication and involvement of all levels of employees. The study attempts to design an application in a personal database system to the employees at Lean department to keep track of the waste elimination database for analysis and evaluation purpose. Likewise, it’s also examined the employees’ problem solving capacity in waste eliminating project. Application in Microsoft Access is considered new in the case study company. The problems that faced are such as the human factors such as the fearful in changing and accepting IT systems and procedures. Application in Microsoft Access is considered new in the case study company. The employees in Lean department can easily keep track on the improvement projects and the management can monitor on the improvement task and problem solving capabilities of the employees. The visual indicators are improved because meaningful chart and reports are generated for visual and filling purpose. Besides, implementing the problem solving cycle in the designed application to improve the problem solving activities which is also an important element in creating continuous improvement culture. As the many factors such as human factors and skills in using the database application are affected the effectiveness of the designed application. The cost saving value after implementation the database application is difficult to obtain as some study subject are difficult to measure in term of cost.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.277.287 2014/07/06 - 16:34

Recent years have witnessed a great deal of interest from both scientific and academic communities in the field of flexible electronic systems. Most flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today’s network oriented society. On the other hand, High Impedance Surfaces have become very popular in the design of contemporary antenna and micro-wave devices due to their wide range of applications derived from their unique electromagnetic properties which significantly enhance the performance of antennas and RF systems. Accordingly, the integration of HIS structures within flexible wireless systems is very beneficial in this growing field of research. In this paper, a systematic review of flexible HIS structures reported in the literature is conducted, which provides the reader with a thorough description and a complete list of state of the art designs intended for flexible wireless systems.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.272.276 2014/06/27 - 14:08

A finite element-finite difference numerical model is developed for predicting non-uniform temperature development in hydrating concrete with respect to time and space. The results obtained from this model can be used bystructural and construction engineers to predict critical thermal stresses induced due to differential temperatures between the core and the surface of the concrete at early ages and between the zero-stress temperatures and the minimum equilibrating ambient temperatures that the concrete experiences during its service life. The prediction of zero-stress temperatures also enables to quantify the extent of built-in curl developed in concrete structures. The finite element is used to space discretization while the finite difference is used to obtain transient solutions of the model. The numerical formulations are then programmed in Matlab. The numerical results were compared with experimental results found in literature and demonstrated very good agreement.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.255.265 2014/05/07 - 20:16

The main intention of this study is to contribute some thoughts on why the tradition of wood carvings in traditional Malay architecture was discontinued at the rise of modern and post-modern architectural works in Malaysia. Although the tradition of wood carvings more or less came to a stop in public architectural works with the development of colonial architecture, this study seeks to clarify the modernistic and post-modern arguments on the problem or issues of ornamentation. Although modernism mainly or seemingly rejected the use of ornaments, there was still a strong strand of its development in the architecture of Frank Lloyd Wright. The western post-modernist architects such as Michael Graves and Charles Jencks went on to develop a discourse on ornamentation under the area of architectural meaning and linguistics. It is expected that this critic paper can segragate and analyse issues and problems of Malay wood carvings and start a further discussion on the development of this traditional heritage which can contribute and reconstruct a better framework for the Architectural Identity of Malaysia.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.241.254 2014/05/07 - 20:16

A finite element-finite difference numerical model is developed for predicting non-uniform temperature development in hydrating concrete with respect to time and space. The results obtained from this model can be used bystructural and construction engineers to predict critical thermal stresses induced due to differential temperatures between the core and the surface of the concrete at early ages and between the zero-stress temperatures and the minimum equilibrating ambient temperatures that the concrete experiences during its service life. The prediction of zero-stress temperatures also enables to quantify the extent of built-in curl developed in concrete structures. The finite element is used to space discretization while the finite difference is used to obtain transient solutions of the model. The numerical formulations are then programmed in Matlab. The numerical results were compared with experimental results found in literature and demonstrated very good agreement.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.261.271 2014/04/28 - 13:52

The main intention of this study is to contribute some thoughts on why the tradition of wood carvings in traditional Malay architecture was discontinued at the rise of modern and post-modern architectural works in Malaysia. Although the tradition of wood carvings more or less came to a stop in public architectural works with the development of colonial architecture, this study seeks to clarify the modernistic and post-modern arguments on the problem or issues of ornamentation. Although modernism mainly or seemingly rejected the use of ornaments, there was still a strong strand of its development in the architecture of Frank Lloyd Wright. The western post-modernist architects such as Michael Graves and Charles Jencks went on to develop a discourse on ornamentation under the area of architectural meaning and linguistics. It is expected that this critic paper can segragate and analyse issues and problems of Malay wood carvings and start a further discussion on the development of this traditional heritage which can contribute and reconstruct a better framework for the Architectural Identity of Malaysia.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.247.260 2014/04/19 - 20:46

This study was carried out to determine the level of same selected metals namely Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Se, Al and V in some imported canned foods and chicken stock purchased from the local market in Riyadh, Saudi Arabia. The measurements were performed using inductively coupled plasma-optical emission Spectrometer (SPECTRO) analytical instruments. The result showed that the average concentration of the elements was 0.0007 for Cu, 0.0197 for Fe, 0.0029 for Mn, 0.0018 for Ni, 0.0120 for Zn and 0.0005 for Cr, 0.001 for Cd, 0.0137 for Al, 0.0079 for AS and 0.0167 for Se. In comparison the concentration of heavy metals and essential metals in the current investigation with World Health Organization and Food and Agriculture Organization WHO/FAO legal limits.The average concentration of all heavy metals and essential elements were much lower than the reference limits. Based on the obtained results it can be concluded that the imported canned foods and chicken stock are free of heavy metals contamination.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.241.246 2014/04/19 - 20:46

This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in order to observe implementation problems. The study goes deeply in the details that have to take into account in order to understand design problems and limitations.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.194.240 2014/04/19 - 20:46

The zonal modeling approach is a new simplified computational method used to predict temperature distribution, energy in multi-zone building and indoor airflow thermal behaviors of building. Although this approach is known to use less computer resource than CFD models, the computational time is still an issue especially when buildings are characterized by complicated geometry and indoor layout of furnishings. Therefore, using a new computing technique to the current zonal models in order to reduce the computational time is a promising way to further improve the model performance and promote the wide application of zonal models. Parallel computing techniques provide a way to accomplish these purposes. Unlike the serial computations that are commonly used in the current zonal models, these parallel techniques decompose the serial program into several discrete instructions which can be executed simultaneously on different processors/threads. As a result, the computational time of the parallelized program can be significantly reduced, compared to that of the traditional serial program. In this article, a parallel computing technique, Open Multi-Processing (OpenMP), is used into the zonal model, Pressurized zOnal Model with the Air diffuser (POMA), in order to improve the model computational performance, including the reduction of computational time and the investigation of the model scalability.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.185.193 2014/04/12 - 23:44

Our objective is to demonstrate the use of Computational Fluid Dynamic (CFD) in building applications. In particular, CFD has been used for temperature and airflow predictions of building spaces conditioned using Under Floor Air Distribution (UFAD) System. The space used is an instrumented laboratory room (old daycare center) located at the University of Wyoming. The use of the CFD simulation results provides insightful analyses of the UFAD design and diffuser locations. The k-ε turbulent model was employed to simulate the environment above an Under-Floor Air Distribution (UFAD) system, where the air is supplied using different configurations of several diffuser locations. Mesh generation was conducted using a pre-processor program, called GAMBIT. The CFD results were obtained using the program FLUENT and show flow and thermal patterns, using temperature and heat flux boundary conditions obtained experimentally. These boundary conditions have been used to predict the nature of convection heat transfer through studying velocity and temperature patterns. A realistic three dimensional model of the UFAD system is used for the simulation.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.171.184 2014/04/12 - 23:44

About 25,000 acres of area underlying the Deep and Dan River Basins in North Carolina has been identified to contain large shale gas reservoirs that could be used for the natural gas production. This study attempted to quantify the impact of potential hydraulic fracturing (or fracking) activities in the existing water resources of North Carolina. Supply and demand analysis was conducted using a water balance approach. Availability of surface water resources was quantified using the streamflow monitoring data of the surrounding area. A general assessment of the water demand for fracking was done using existing literature data and assumptions. Finally, a comparison was made between the water demand due to fracking and the water availability from nearby water sources. The preliminary analysis concluded that the surface water resources of North Caroline will not be affected at all as far as water quantity is concerned. However, whether extracting the shale gas of North Carolina is a good decision or not depends on the complete evaluation of the shale reservoirs and how well environmental impacts can be addressed.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.165.170 2014/04/12 - 23:44

This study presents an effective navigation architecture that combines ‘go-to-goal’, ‘avoid-obstacle’ and ‘follow-wall’ controllers into a full navigation system. A MATLAB robot simulator is used to implement this navigation control algorithm. The robot in the simulator moves to a goal in the presence of convex and non-convex obstacles. Experiments are carried out using a ground mobile robot, Dr Robot X80SV, in a typical office environment to verify successful implementation of the navigation architecture algorithm programmed in MATLAB. The research paper also demonstrates algorithms to achieve tasks such as ‘move to a point’, ‘move to a pose’, ‘follow a line’, ‘move in a circle’ and ‘avoid obstacles’. These control algorithms are simulated using Simulink models.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.149.164 2014/04/12 - 23:44

The purpose of this study was to evaluate the benefits of replacing Ordinary Portland Cement (OPC) with Corncob Ash (CCA) blended cements. The cement industry contributes considerable amount of Carbon Dioxide (CO2) emissions into the atmosphere. The main contribution of CO2 emissions from cement production results from the process of creating Calcium Oxide (CaO) from limestone (CaCO3) commonly known as the calcination process. Blending OPC with a pozzolanic material will assist in the reduction of CO2 emissions due to calcination as well as enhance the quality of OPC. There are various pozzolanic materials such as fly ash, rice husk, silica fume and CCA that could be promising partial replacement for OPC. In this study, CCA will serve as the primary blending agent with OPC. An experiment was performed to designate an appropriate percentage replacement of CCA that would comply with specific standards of cement production. The experimental plan was designed to analyze compressive strength, workability and thermal performance of various CCA blended cements. The data from the experiment indicates that up to 10% CCA replacement could be used in cement production without compromising the structural integrity of OPC. In addition, it was found that the compressive strength and workability of the resulting concrete could be improved when CCA is added to the mixtures. Furthermore, it was shown that the introduction of 10% CCA can lead to significant reduction in thermal conductivity of the mixture.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.137.148 2014/04/12 - 23:44

Excessive groundwater pumping can decrease the amount of fresh water flowing towards the coastal discharge areas, allowing salt water to be drawn into the fresh water zones of coastal aquifers. This process gets complicated with the frequent change behavior of groundwater levels in observation wells. The fluctuation happens due to various reasons but can be directly correlated with the precipitation patterns. We hypothesized that the salinity of water adds to the complexity and affects the causal relationship between precipitation and well water depth. Relevant data (precipitation, well water depth and water salinity) were collected for analysis from a monitoring site located in North Carolina. Analytical study of mean monthly data identified the lack of a strong correlation between the water table depth and precipitation. Moreover, the salinity was found to be slightly correlated with precipitation. A significant correlation was expected between the precipitation and well water depth and salinity should have been more closely related to the precipitation. The lack of correlation is mainly attributed to the lack of available daily data, especially in the case of salinity.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.115.121 2014/04/12 - 23:44

Several methods of impact assessment have been developed over the years which basically incorporate future climate projections of atmospheric-ocean circulation based climate models into the simulation of land surface hydrological processes. This study attempted to evaluate three methods of climate change impact assessment: (a) Frequency perturbation method, (b) direct method and (c) delta change method. A well-calibrated hydrologic model, Soil and Water Assessment Tool (SWAT), was used in watershed simulation for climate projections of mid-century by ten Global Climate Models (GCMs). The frequency perturbation method found precipitation decrease by 17% and reduction in temperature by 0.43°C on an average annual basis. The changes when applied through the simulation model resulted in 13% reduction in Evapotranspiration (ET) and 25% reduction in water yield. Other two methods produced different set of results. It’s not conclusive to say which method performed better. The frequency perturbation method produced most extreme changes while direct method had the least magnitude of changes projected for the mid-century. Changes in ET and water yield due to changes in future climate are likely to have severe implications for the water availability. However, more research is needed to evaluate several other impact assessment methods for more reliable analysis.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.122.128 2014/04/12 - 23:44

A simplified model for illuminance prediction has been developed to estimate the indoor level of lighting under artificial lighting. As well, illuminance in several locations of three schools has been measured under several conditions: Blinds up/lights on, blinds up/lights off, blinds down/lights on, blinds down/lights off. The experimental data of the case “blinds down/lights on” has been compared to the model developed and the results are very encouraging. The purpose of this study is to identify the level of illuminance in elementary schools classroom, to compare it to the IES requirements and the values predicted by the program developed. A parametric study has been performed to study the effect of the Light Loss Factor (LLF) and the luminous power on the lighting and energy performance of the illumination system.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.129.136 2014/04/12 - 23:44

Groundwater level data is an important indicator of the availability and distribution of groundwater resources of the region. However, it is difficult to understand the continuous and discrete fluctuations of the groundwater level which is controlled by various factors. This study demonstrated the use of Fourier series integrated with the least square estimation method to predict the groundwater level especially in the case of seasonal-sensitive groundwater fluctuations. It was observed that the designed method was able to model the groundwater-table data, collected at the Hagan Stone Park station in Greensboro, North Carolina, with a fair degree of accuracy with a testing mean square error of 0.0735.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.99.104 2014/04/12 - 23:44

A laboratory study was conducted to investigate the effects of Amine based modifier on rheological characteristics of particle filled viscous medium such as asphalt binder in presence of Recycled Asphalt Shingles (RAS). In this study, virgin asphalt binder (PG 64-22), three different percentages (20, 30 and 40%) of tear-off shingles and modifiers; Rediset, Evotherm and Bio-binder were used. The tear-off shingles acquired from local reroofing company in Greensboro, North Carolina; were finely grinded (85% passing of sieve # 200). The virgin binder and different percentages of RAS were then blended at 180°C using shearing speed of 400 rpm. Following that themixture was blended with 1.5% of Rediset, 0.5% of Evotherm and 5% of bio-binder. The properties of the blended binder were studied using the Rotational Viscometer (RV) equipped with two different spindle types:- One was Smooth Cylindrical spindle (SC4-27D) and the other one was Vane spindle (V 73). The analysis showed that the viscosity was increased with increasing the RAS percentage. Furthermore, the viscosity measured by vane spindle was continuously higher than the value measured by smooth spindle; however the difference between the two measurements reduced as the blending were improved using modifiers. Moreover, temperature found to be the main contributor to reduction of the viscosity in both spindles cases. In addition the coefficient of variation was significantly lower in the case of vane spindle, indicating that the vane spindle could be more appropriate in measuring viscosity of particle filled viscous medium such as RAS asphalt. Based on the experimental result an empirical index called blending index was introduced in this study to measure the blending behavior and status for modified mixtures. As expected it was found that the blending index increases as the temperature and rotational speed increases. In other word, higher temperature and shearing rate could enhance blending resulting in higher blending index. The blending index was further used as a laboratory measure to compare effectiveness of various additives in enhancing blending of RAS modified mixtures. It was shown that among three modifiers used in this study, the bio-binder was more effective to increase the blending index.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.105.114 2014/04/12 - 23:44

Zonal models combine the simplicity of single and multi-zone models with the comprehensiveness of Computational Fluid Dynamics (CFD) models and thus become a better substitute to predict detailed thermal and airflow behaviors in building. Based on a geometric partitioning of a room into a number of subzones, these models give more accurate and detailed results than the single or multi-zone modeling approaches and use less computer resource than CFD models. Nevertheless, most of the zonal models have to face a difficulty involving the limits of the simplification that need to be considered without losing accuracy and comprehensiveness. A new zonal model, called Pressurized zOnal Model using the Momentum Equation (POMME), has been developed, in which a simplified numerical model, representing various heat and mass transfer conservation equations is used. The program solver is similar to those used for CFD programs and is based on the finite-volume numerical techniques, the staggered grid formulation, the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm and other methods. The validation of this new zonal model has been accomplished by comparing its results with those obtained from the CFD software: PHOENICS. The results demonstrate not only the strength of the zonal model POMME in predicting the indoor airflow and thermal conditions, without the involvement of additional sub-models, but also its ability to provide relatively accurate results for building enclosures.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.77.87 2014/04/12 - 23:44

Several building simulation programs have been developed for design, analysis and prediction of the distribution of temperature, airflow and heat transfer between inside and outside of a building and/or between different zones of the same building. These programs are categorized as mono-zone models, multi-room models, zonal models, Computational Fluid Dynamics (CFD) models and multi-zone models. The number of computer programs continues to increase, each reflecting different objectives and concerns. Some of these computer programs are dedicated to research and others to design and auditing. However, none of the existing computer programs is able to translate automatically various steps of the design process as actually performed by design Architectural Engineering firms. This study addresses different levels of multi-room simulation programs developed through the last four decades. Two case studies using multi-room programs have been exposed to illustrate the appropriate use of various levels of this approach for design and analysis.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.88.98 2014/04/12 - 23:44

The life expectancy of Asphalt Binder (AB) has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B) is a naturally occurring inorganic mineral. Bio-char is the waste product from bio-binder production. Bio-binder is produced from swine manure using a thermochemical conversion process. This process is then followed by a filtration procedure where the bio-char is produced. Chemical and physical properties of bio-char showed a significant presence of carbon which could in turn enhance asphalt flow properties and reduce the rate of asphalt oxidation. In this study several mixtures are designed and evaluated using Rotational Viscometer testing (RV) and X-Ray Diffraction (XRD). Nano-clay is blended at 2 and 4% by weight, with and without bio-binder (5% by weight of dry mass). Bio-char is grinded to nano scale and added to the virgin asphalt binder (PG 64-22) at 2, 5 and 10% by weight. The study results showed that introduction of nano-clay could be effective in reducing temperature susceptibility of asphalt binder.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.66.76 2014/04/12 - 23:44

The study discusses the applications of CO2-based demand-controlled ventilation DCV strategy integrated with the economizer for air source heat pumps in schools, investigates their impact on the annual heating, cooling and total energy consumption, also determines the potential savings achieved in different USA locations. The study includes detailed energy analysis on an existing middle school through whole building simulation energy software. The simulation model is first calibrated and checked for accuracy using actual monthly utility data. This model is then used for savings calculations resulted from a combination of air-side economizer and CO2-based DCV and with various occupancy profiles and locations. The results show that a significant saving could be obtained as compared to the actual operating strategy implemented in the existing system and this saving depends mainly on the actual occupancy profile and building locations.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.58.65 2014/04/12 - 23:44

Advanced Energy Management Control Systems (EMCS) offer an excellent means of reducing energy consumption in Heating, Ventilating and Air Conditioning (HVAC) systems while maintaining and improving indoor environmental conditions. This can be achieved through the use of computational intelligence and optimization with a building automation system and multiple sensors, which can be quite expensive. However, energy awareness and proper scheduling achieve the best opportunities to save energy with little to no cost for existing facilities. These “low-tech/low-cost” ideas are easily implemented and quickly reduce utility costs. This article includes actual utility data and information gathered over the past 20 years while performing energy audits at several K-12 Schools in North Carolina, discusses well known and documented control strategies that are rarely implemented in most school districts and universities and will extrapolate savings for an entire school district based on real data. These processes can also be integrated into an EMCS to perform several intelligent functions achieving optimal system performance. This article focuses on control strategies utilizing time-of-day scheduling that can be used with 7-day programmable thermostats, electronic time controllers and a Building Automation System (BAS). These controllers (7d-prog. thermostat, electronic time controller and BAS) will achieve lower energy consumption while maintaining occupant comfort by performing and prioritizing the appropriate actions. Real savings can be achieved quickly by utilizing these common sense approaches to control existing HVAC and lighting systems in schools.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.45.57 2014/04/12 - 23:44

A large portion of energy use in buildings is attributed to air movement devices. Accurate estimation of fan performance is a key element in maximizing fan efficiency. This study proposes a new fan model that can be used in several applications such as optimization and fault detection and can also be incorporated into any commercial building models. The model uses a numerical analysis based on an interpolation technique for the data generated by basic fan laws. It can use any two variables among all four variables of airflow rate, total fan pressure, speed and power as inputs or outputs. Another advantage of this model is the flexibility of using any size of data for calibration, obtained either from manufacturers or field measured data. The model was tested for accuracy using two different manufacturers’ data of roof top unit packages with capacity ranging from 2 to 20 tons. Furthermore, the model was evaluated and tested on an actual VAV system using three months’ worth of measured data. The results show that the model can provide accurate estimation with the Coefficient of Variance (CV) less than 2% and it can be used for several applications.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.36.44 2014/04/12 - 23:44

In this study, experimental and simulation studies were performed in a building equipped with an UFAD system in order to investigate the applicability of a new approach designed for prediction of the energy consumption of a residential building with an UFAD system. In this approach, a zonal model, Pressurized zOnal Model with the Air diffuser (POMA), was coupled with a thermal jet model and integrated into a traditional multizone thermal model. The coupled model was verified experimentally. This integrated model has the ability to take into account the characteristics of an UFAD system and thus accurately simulate its energy consumption. A case study was carried out using both approaches: Multi-zone approach and the new developed integrated zonal/jet/multizone model. A quantitative comparison, in terms of energy demand of a building with an UFAD system, shows that the difference can reach 14% and thus indicates that the traditional multizone modeling approach is not appropriate to use for UFAD system in the building energy prediction.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.23.35 2014/04/12 - 23:44

About 25,000 acres of area underlying the Deep and Dan River Basins in North Carolina has been identified to contain large shale gas reservoirs that could be used for the natural gas production. This study attempted to quantify the impact of potential hydraulic fracturing (or fracking) activities in the existing water resources of North Carolina. Supply and demand analysis was conducted using a water balance approach. Availability of surface water resources was quantified using the streamflow monitoring data of the surrounding area. A general assessment of the water demand for fracking was done using existing literature data and assumptions. Finally, a comparison was made between the water demand due to fracking and the water availability from nearby water sources. The preliminary analysis concluded that the surface water resources of North Caroline will not be affected at all as far as water quantity is concerned. However, whether extracting the shale gas of North Carolina is a good decision or not depends on the complete evaluation of the shale reservoirs and how well environmental impacts can be addressed.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.161.166 2014/04/10 - 23:50

This study was carried out to determine the level of same selected metals namely Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Se, Al and V in some imported canned foods and chicken stock purchased from the local market in Riyadh, Saudi Arabia. The measurements were performed using inductively coupled plasma-optical emission Spectrometer (SPECTRO) analytical instruments. The result showed that the average concentration of the elements was 0.0007 for Cu, 0.0197 for Fe, 0.0029 for Mn, 0.0018 for Ni, 0.0120 for Zn and 0.0005 for Cr, 0.001 for Cd, 0.0137 for Al, 0.0079 for AS and 0.0167 for Se. In comparison the concentration of heavy metals and essential metals in the current investigation with World Health Organization and Food and Agriculture Organization WHO/FAO legal limits.The average concentration of all heavy metals and essential elements were much lower than the reference limits. Based on the obtained results it can be concluded that the imported canned foods and chicken stock are free of heavy metals contamination."

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.208.213 2014/04/09 - 14:40

This study presents an effective navigation architecture that combines ‘go-to-goal’, ‘avoid-obstacle’ and ‘follow-wall’ controllers into a full navigation system. A MATLAB robot simulator is used to implement this navigation control algorithm. The robot in the simulator moves to a goal in the presence of convex and non-convex obstacles. Experiments are carried out using a ground mobile robot, Dr Robot X80SV, in a typical office environment to verify successful implementation of the navigation architecture algorithm programmed in MATLAB. The research paper also demonstrates algorithms to achieve tasks such as ‘move to a point’, ‘move to a pose’, ‘follow a line’, ‘move in a circle’ and ‘avoid obstacles’. These control algorithms are simulated using Simulink models.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.145.160 2014/04/07 - 14:58

This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in order to observe implementation problems. The study goes deeply in the details that have to take into account in order to understand design problems and limitations.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.161.207 2014/04/07 - 14:58

The purpose of this study was to evaluate the benefits of replacing Ordinary Portland Cement (OPC) with Corncob Ash (CCA) blended cements. The cement industry contributes considerable amount of Carbon Dioxide (CO2) emissions into the atmosphere. The main contribution of CO2 emissions from cement production results from the process of creating Calcium Oxide (CaO) from limestone (CaCO3) commonly known as the calcination process. Blending OPC with a pozzolanic material will assist in the reduction of CO2 emissions due to calcination as well as enhance the quality of OPC. There are various pozzolanic materials such as fly ash, rice husk, silica fume and CCA that could be promising partial replacement for OPC. In this study, CCA will serve as the primary blending agent with OPC. An experiment was performed to designate an appropriate percentage replacement of CCA that would comply with specific standards of cement production. The experimental plan was designed to analyze compressive strength, workability and thermal performance of various CCA blended cements. The data from the experiment indicates that up to 10% CCA replacement could be used in cement production without compromising the structural integrity of OPC. In addition, it was found that the compressive strength and workability of the resulting concrete could be improved when CCA is added to the mixtures. Furthermore, it was shown that the introduction of 10% CCA can lead to significant reduction in thermal conductivity of the mixture.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.133.144 2014/04/04 - 15:40

Excessive groundwater pumping can decrease the amount of fresh water flowing towards the coastal discharge areas, allowing salt water to be drawn into the fresh water zones of coastal aquifers. This process gets complicated with the frequent change behavior of groundwater levels in observation wells. The fluctuation happens due to various reasons but can be directly correlated with the precipitation patterns. We hypothesized that the salinity of water adds to the complexity and affects the causal relationship between precipitation and well water depth. Relevant data (precipitation, well water depth and water salinity) were collected for analysis from a monitoring site located in North Carolina. Analytical study of mean monthly data identified the lack of a strong correlation between the water table depth and precipitation. Moreover, the salinity was found to be slightly correlated with precipitation. A significant correlation was expected between the precipitation and well water depth and salinity should have been more closely related to the precipitation. The lack of correlation is mainly attributed to the lack of available daily data, especially in the case of salinity.

http://www.thescipub.com/abstract/10.3844/ajeassp.2014.111.117 2014/03/28 - 11:03