Architectural Engineering Commons^™

Fault Diagnosis Of Refrigerant Charge Based On Pca And Decision Tree For Variable Refrigerant Flow Systems, Jiangyan Liu, Huanxin Chen, Jiangyu Wang, Guannan Li, Haorong Li, Wenju Hu

Durham School of Architectural Engineering and Construction: Faculty Publications

Variable refrigerant flow (VRF) systems are easily subjected to performance degradation due to refrigerant leakage, mechanical failure or improper maintenance after years of operation. Ideal VRF systems should equip with fault detection and diagnosis (FDD) program to sustain its normal operation. This paper presents the fault diagnosis method for refrigerant charge faults of variable refrigerant flow (VRF) systems. It is developed based on the classification and regression tree (CART) algorithm. Data of the experimental VRF system is used to test the advantages of the CART method. Results show that the decision tree can achieve desirable diagnosis efficiency on undercharge faults, …

Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pumping of Fresh Concrete is of Utmost Importance for Concrete Practice. Required Pumping Pressures Are Typically Estimated based on Design Charts. However, with the Increased Use of Chemical Admixtures and the Development of More Flowable Concrete Mixtures, the Accuracy of Traditional Design Charts is Questioned. in Recent Years, Significant Progress Has Been Obtained in Understanding the Flow of the Material in the Pumping Pipe, Including the Behavior of the Lubrication Layer Near the Pipe Surface. in Comparison with Traditional Design Charts, This Results in More Reliable Pressure Predictions When Considering Very Fluid Concrete Types Like Self-Consolidating Concrete. Some Remaining Challenges …

Cognitive Radio For Smart Grid With Security Considerations, Khaled Shuaib, Ezedin Barka, Nedaa Al Hussien, Mohammed Abdel-Hafez, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

In this paper, we investigate how Cognitive Radio as a means of communication can be utilized to serve a smart grid deployment end to end, from a home area network to power generation. We show how Cognitive Radio can be mapped to integrate the possible different communication networks within a smart grid large scale deployment. In addition, various applications in smart grid are defined and discussed showing how Cognitive Radio can be used to fulfill their communication requirements. Moreover, information security issues pertained to the use of Cognitive Radio in a smart grid environment at different levels and layers are …

A Prediction Method For Overall Economic Value Of Fault Detection And Diagnostic Tools For Rooftop And Split Systems, David Yuill, James Braun

Durham School of Architectural Engineering and Construction: Faculty Publications

Fault detection and diagnostics (FDD) tools for air-conditioning application may perform well or poorly, but it is difficult to characterize this performance in a meaningful way. Some recently proposed evaluation techniques have provided various statistics to characterize FDD performance, but these results can be difficult for a potential adopter of FDD to understand. A new method of characterizing FDD performance by predicting the overall economic value of the FDD tool is proposed in this paper. It is applicable to FDD tools intended for air-cooled unitary airconditioners, such as rooftop units (RTU) and split systems. The method gives an estimated dollar …

Identification Of Key Performance Tasks To Demonstrate The Benefit Of Introducing The Facilities Manager At An Early Stage In The Building Information Modelling Process On Public Sector Projects In Ireland., Barry Mcauley

Doctoral

Modelling (BIM) governed process was investigated in this thesis. Governments are now seeking a more rewarding methodology in the management and procurement of public sector building assets. This has seen an integrated focus by International Governments on BIM as a partial solution in both managing and procuring public sector building assets. Despite BIM bringing the Facility Manager closer to project conceptualisation, there was still a reluctance and a lack of perceived benefits of having them involved earlier in the design phase. There remains a lack of clear evidence on what improved contribution the Facilities Manager can provide. This thesis provides …

Normalized Effect Of Condenser Fouling And Refrigerant Charge On Performance Of Vapor Compression Air Conditioning Systems, Mehdi Mehrabi, David Yuill

Durham School of Architectural Engineering and Construction: Faculty Publications

Several laboratory experiments have studied the effect of faults on vapor compression cycle air-conditioning systems. There has been a particular focus on refrigerant charge variation, which is believed to be quite common in air conditioners, and a lesser focus on heat exchanger fouling. The majority of the published results evaluate the fault effects on particular system operating parameters in one unit. For example, the effect on capacity and efficiency are typically evaluated. The results differ from one study to the next. The current paper summarizes the effects for all of the results available in the literature for condenser fouling and …

Student Absenteeism And The Comparisons Of Two Sampling Procedures For Culturable Bioaerosol Measurement In Classrooms With And Without Upper Room Ultraviolet Germicidal Irradiation Devices, Chunxiao Su, Josephine Lau, Shawn G. Gibbs

Durham School of Architectural Engineering and Construction: Faculty Publications

Upper room ultraviolet germicidal irradiance (UVGI) has been shown to reduce the concentration of bioaerosols in controlled chambers. However, there is a lack of experimental results on the reduction of bioaerosol concentrations by UVGI devices in actual uncontrolled buildings. This study was carried out in an American elementary school in the Midwest. Two sampling procedures were carried out in six selected classrooms with similar dimensions that were separated into two groups: (1) UVGI exposure group and (2) non-UVGI control group. Two-stage Tisch culturable impactors were utilized to collect airborne culturable bacteria and fungi. Monthly samples were collected during unoccupied period …

Fault Detection And Diagnosis Process For Oversizing Design On Multiple Packaged Air-Conditioning Units, Denchai Woradechjumroen, Haorong Li, Thanapat Promwattanapakee

Durham School of Architectural Engineering and Construction: Faculty Publications

Heating, ventilation, air-conditioning and Refrigeration (HVAC&R) systems are seldom designed or commissioned properly. The situation leads to abrupt or degradation faults resulting in inefficient energy uses, excessive energy consumption and high service costs. To solve these aforementioned problems, fault detection and diagnosis (FDD) is utilized to firstly detect any abnormal conditions of a system and then diagnoses and determines their causes. In order to apply this concept in HVAC oversizing designs, this paper proposes the state-of-art procedure of a FDD procedure for analyzing the inherently faulty design (oversizing) of multiple packaged air-conditioning units used to supply cooling for an open …

Compressor Having A Control And Dagnostic Module, Hung M. Pham, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

An apparatus includes a Voltage sensor, a current sensor, and a controller. The Voltage sensor measures Voltage values of alternating current power Supplied to a capacitor. The capaci tor is electrically coupled to a compressor. The current sensor measures current values of the alternating current power. The controller is configured to receive the Voltage values and the current values. The controller is configured to determine a first power factor value based on at least one of the voltage values and at least one of the current values. The controller is configured to selectively detect a first capacitor fault in response …

Geotechnical State-Of-The-Art In Guatemala -- Ground Stabilization, Fernando Rafael Callejas Benitez

Doctoral Dissertations

"History provides an understanding of the present and in a way, a guide for the future. The state-of-the-art is often referred to as a snapshot of the most significant works and contributions made in a field of study; In this case the focus is on Guatemalan geotechnical engineering. This study presents a comprehensive description of the different events that impulse geotechnical engineering in Guatemala.

As part of the description of the state-of-the-practice an investigation of the different human (engineers/contractors) and physical resources (laboratories/field equipment) and their capabilities are presented. An overview of the civil engineering programs is presented. Then, the …

Influence Of The Substrate Characteristics On The Bond Behavior Of Pbo Frcm-Concrete Joints, Tommaso D'Antino, Lesley H. Sneed, Christian Carloni, Carlo Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber Reinforced Cementitious Matrix (FRCM) composites can be employed as a valid alternative to Fiber Reinforced Polymers (FRP) composites for strengthening existing reinforced concrete (RC) structures. The weakness of FRCM-concrete joints has been reported to be at the matrix-fiber interface rather than within the concrete substrate, as is usually reported in the case of FRP-concrete joints. The experimental investigations regarding FRCM strengthening available in the literature have been performed by applying the FRCM composite onto a surface that was treated before the application, usually by grinding or sandblasting. However, the role of the substrate characteristics on the failure mechanism of …

A Hybrid Approach For Increasing Baffling Factors In Contact Tanks, Justin J. Kattnig, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A novel approach using a hybrid combination of internal baffles and industrial packing material is investigated in order to optimize the hydraulic residence time of a 1,500-gal rectangular concrete tank. Hydraulic residence time, which is commonly classified using the baffling factor (BF), was determined from residence time distribution curves obtained using both computational fluid dynamics (CFD) simulations and physical tracer studies. CFD simulations were used to model two scenarios. The first scenario was a base system consisting of an unbaffled concrete tank, and the second scenario was a two-baffle system. Computational simulation results were experimentally validated via tracer studies on …

Estimation On Gibbs Entropy For An Ensemble, Lekhya Sai Sake

Electronic Theses, Projects, and Dissertations

In this world of growing technology, any small improvement in the present scenario would create a revolution. One of the popular revolutions in the computer science field is parallel computing. A single parallel execution is not sufficient to see its non-deterministic features, as same execution with the same data at different time would end up with a different path. In order to see how non deterministic a parallel execution can extend up to, creates the need of the ensemble of executions. This project implements a program to estimate the Gibbs Entropy for an ensemble of parallel executions. The goal is …

Exploring Emerging Technologies For The Built Environment Circa 2015 For Use In Architectural Engineering And Related Majors, Connor J. Hanlon

Architectural Engineering

For this senior project I am seeking to combine my knowledge of Structural Engineering with Construction Management. For this task, I have decided to look at Building Information Modeling (BIM). In this project I investigate the BIM tools Trimble Tekla Structures and Autodesk Navis- works Manage. Tekla is a modeling, fabrication, and design program. Navisworks is a visualiza- tion and Clash Detection tool. For this project I have identiÅied two main goals relating to Navis- works and Tekla:

1. Create content to allow students and professors learn how to use Tekla and Navisworks

2. Determine the capabilities of these softwares, and Åigure …

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Tron 2.0 - The Experience, Alecsandro G. Vitale, Alexander W. Billings, Jordan Delfino, William Beechinor, Kelly Rorden

Architectural Engineering

The goal of this senior project was to come up with a structural-engineering-related schematic design for a roller coaster to be installed in Disneyland called TRON 2.0: The Experience. This involved looking at both design processes that we had already learned through our curriculum as well as researching concepts that were previously foreign to us, namely the dynamic application of loads and the effects of fatigue stresses.

A story was established based on the source material: the TRON movies produced by Walt Disney Studios. Thematic elements from the story were used as the basis for design implications that would become …

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Block Sparse Memory Improved Proportionate Affine Projection Sign Algorithm, J. Liu, S. L. Grant

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A block sparse memory improved proportionate affine projection sign algorithm (BS-MIP-APSA) is proposed for block sparse system identification under impulsive noise. The new BS-MIP-APSA not only inherits the performance improvement for block-sparse system identification, but also achieves robustness to impulsive noise and the efficiency of the memory improved proportionate affine projection sign algorithm (MIP-APSA). Simulations indicate that it can provide both faster convergence rate and better tracking ability under impulsive interference for block sparse system identification as compared with APSA and MIP-APSA.

Cultural Change Through Bim: Driving Lean Transformation In Education, Avril Behan, Malachy Mathews, Kevin Furlong, Ciara Ahern, Una Beagon, Peter Brennan, Colin Conway, Lee Corcoran, Pierce Fahy, Alan Hore, Barry Mcauley, Trevor Woods

Conference papers

This paper presents a case study of how the adoption of BIM-based practices in the AECO industry is being reflected by cultural change in higher education in Ireland. The silo-mentality that has dominated the AECO sector for more than a century has, despite numerous reorganisations, been replicated in the structures of educational institutions, including in Dublin Institute of Technology since the inception of its founding colleges in the late 1800s. Most AECO programmes must include content that is external to the programme’s specific discipline. Through the School structures of the Institute, delivery of such content is known as "service teaching" …

"Defining Job Titles And Career Paths In Bim", Malachy Mathews

Conference papers

Ireland is undergoing a digital transformation. Some industries particularly in the areas of travel and retail have been radically transformed. However many industries are facing their biggest challenge in their existence already weakened by the economic crisis and constrained by their legacy business, it will be difficult for them to adapt and embrace the new rules dictated by digital change. Irelands design and construction industry is on the cusp of a digital transformation with early adopters now deriving some benefits from a move to a building information modeling (BIM) process. Digital transformation cannot happen unless there are personnel with the …

Radial Strain Behaviors And Stress State Interpretation Of Soil Under Direct Simple Shear, Xin Kang, Yao Cheng, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Radial strain behaviors and stress state interpretation methods of silica sand consolidated at different K0 values under modified direct simple shear were investigated in this research. Consolidated drained triaxial compression test, direct shear box test, and wire reinforced direct simple shear tests were conducted, and the test results were compared and linked with the modified direct simple shear tests. Based on the observed testing data, simple shear specimens with constant lateral stress exhibited relatively small radial strain during shear, especially under small shear strains. After the peak shear resistance has mobilized, radial strain increased rigorously until the specimen failed. Confining …

Benchmark Problems For Large Strain Consolidation, Patrick J. Fox, Hefu Pu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modeling of the one-dimensional consolidation process for soil and other compressible porous media is important for a variety of engineering applications. This paper presents solutions for two benchmark problems for large strain consolidation of a saturated soil layer that can be used to check other analytical and numerical analysis methods. The solutions include effects of vertical strain, soil self-weight, nonlinear constitutive relationships, and changing material properties during the consolidation process. High-accuracy data are presented for each problem and include changes of settlement, void ratio, and excess pore pressure with time.

A Comparison Of The Bond Behavior Of Pbo-Frcm Composites Determined By Double-Lap And Single-Lap Shear Tests, Lesley Sneed, T. D'Antino, C. Carloni, C. Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the results of an investigation on the bond behavior and stress-transfer mechanism of polyparaphenylene benzo isoxazole (PBO) fiber-reinforced cementitious matrix (FRCM) composites bonded to a concrete substrate using double-lap and single-lap shear tests. Results of double-lap shear tests with different composite bonded lengths and widths are presented and compared with those from single-lap shear tests previously reported by the authors. The idealized load response developed from single-lap shear tests is found to characterize the response of the composite in double-lap shear tests, although with a few key differences. With the double-lap shear test, load redistribution among the …

Stable Isotope-Enabled Pathway Elucidation Of 2,4-Dinitroanisole Metabolized By Rhizobium Lichtii, Hunter W. Schroer, Kathryn L. Langenfeld, Xueshu Li, Hans Joachim Lehmler, Craig L. Just

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recently developed military explosives are safer to handle, but more environmentally mobile, than traditional explosives. The new insensitive munitions, including 2,4-dinitroanisole (DNAN), have been sparsely studied, making the use of bacterial and/or plant-based remediation approaches unfeasible without further information about the transformation of these compounds. To that end, Rhizobium lichtii isolated from willow tree tissues were studied and observed to completely degrade 5 mg L-1 DNAN within 24 h in liquid media with added carbon and nitrogen. The use of DNAN, [13C6] DNAN, and [15N2] DNAN enabled the identification of 11 previously unknown metabolites resulting from sulfation, acetylation, and/or methylation …

Designing A Resilient Building In The Coastal Zone, Don Kranbuehl, David Pryor

October 30, 2015: Beyond Toolkits: Adaptation Strategies and Lessons

No abstract provided.

Rans Modeling Of Stably Stratified Turbulent Boundary Layer Flows In Openfoam®, Jordan M. Wilson, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Quantifying mixing processes relating to the transport of heat, momentum, and scalar quantities of stably stratified turbulent geophysical flows remains a substantial task. In a stably stratified flow, such as the stable atmospheric boundary layer (SABL), buoyancy forces have a significant impact on the flow characteristics. This study investigates constant and stability-dependent turbulent Prandtl number (Prt) formulations linking the turbulent viscosity (νt) and diffusivity (κt) for modeling applications of boundary layer flows. Numerical simulations of plane Couette flow and pressure-driven channel flow are performed using the Reynolds-averaged Navier-Stokes (RANS) framework with the standard k-ϵ turbulence model. Results are compared with …

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

Enhanced Series-Parallel Model For Estimating The Time-Dependent Thermal Conductivity Of Fly Ash Soil Mixtures, Xin Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An enhanced series-parallel (S-II) model of one-dimensional conductive heat flow through a unit cell was developed to estimate the time-dependent thermal conductivity of Class C fly ash stabilized soils. The unit cell is composed of three separate heat flow paths: a continuous path through solid contacts (soil contacts, fly ash contacts, and soil fly ash contacts) in parallel arrangement, a series-parallel path of solids in a series arrangement with a parallel arranged path of solid-miniscule pores (miniscule portion of solid water and miniscule portion of solid air), and a continuous path through water and air in parallel arrangement. The solid-miniscule …

The Bridge Newsletter Winter 2015, Missouri University Of Science And Technology

The Bridge Newsletter

-S&T’s Solar House Design Team sets out to redefine the American housing market
-A monumental anniversary
-Academy awards Sneed
-ASCE honors Holmes

Pigs Feet, Jesse W. Standlea

The Transdisciplinary STEAM+ Journal

My sculpture “Pigs Feet” has literal foundations upon casts of live pig’s feet. I locally sourced the pig’s feet before casting them. My sculpture makes use of a once cutting edge casting technology, alginate. Alginate molds were once the standard in dentistry. Alginate is an appealing casting material as it is refined from brown seaweeds, is both food and skin safe, it is suitable for educators, for artists and engineers alike.

Assessment Of Empirical Equations For The Compression Index Of Fine-Grained Soils In Missouri, Site Onyejekwe, Xin Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of correlations and empirical relationships in geotechnical engineering provides a fast, cost-effective means of predicting the value of a parameter based on the values of certain other, possibly more easily determined, parameters. The correlation between two or more soil properties has been found to be dependent in varying degrees on soil type, the testing method used to obtain the numerical value of the parameter itself and the homogeneity of the soil. Many empirical correlations among soil properties have been published. These correlations, based on widely sourced data, may not be appropriate for local situations. Hence, there is a …