Engineering Commons^™

Effects Of Accelerated Carbonation Curing On Co2 Sequestration And On The Compressive Strength Of Concrete Masonry Units, Barry Gilroy, Leon Black, David Thompson, Ronan Hogan, Niall Holmes

Conference papers

The global consumption of Portland cement has risen to over 4 billion tonnes per annum. Its manufacture is energy and carbon intensive and approximately 900 kg of CO2 is emitted into the atmosphere for each tonne of Portland cement produced. The International Energy Agency (IEA) roadmap sets out a goal to reduce emissions due to cement production to 18 % below 2006 levels by 2050. Concrete has the potential to re-absorb CO2 by the process of carbonation, where it reacts with CaO in the concrete to form calcium carbonate. Accelerated carbonation curing (ACC) is a technique for curing fresh concrete …

Characterization And Performance Of Cement-Based Thermoelectric Materials, Ruchita Jani, Niall Holmes, Roger P. West, Kevin Gaughan, Xiaoli Liu, Esther Orisakwee, Conrad Johnston, Ming Qu, Jorge Kohanoff, Lorenzo Stella, Hongxi Yin

Conference papers

Thermoelectric materials enable direct conversion of thermal energy to electricity. Ambient heat energy harvesting could be an effective route to convert buildings from being energy consumers to energy harvesters, thus making them more sustainable. There exists a relatively stable temperature gradient (storing energy) between the internal and external walls of buildings which can be utilized to generate meaningful energy (that is, electricity) using the thermoelectric principle. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, ongoing work on developing and characterizing a cement-based thermoelectric material is presented. Samples are …

Thermal Control Development Of A Proton Exchange Membrane Fuel Cell System, Ola Mohammed Taha Al-Shalash

Mechanical Engineering Theses

A fuel cell is an electrochemical energy conversion device that uses fuel to generate electricity. It basically converts the chemical energy of reactants directly into electricity without combustion. In a Proton Exchange Membrane Fuel Cell (PEMFC), the reactants, hydrogen and oxygen, are fed into the two electrodes, anode and cathode, respectively. A reaction takes place at each electrode and produces electricity, as well as water, and heat as the by-products. In order to maximize performance of a fuel cell, many factors can be considered for tuning and control. Temperature management is one of these factors.

A thermal-fluid model of a …

Multidirectional Cylindrical Piezoelectric Force Sensor: Design And Experimental Validation, Ye Rim Lee, Justin Neubauer, Kwang Jin Kim, Youngsu Cha

Mechanical Engineering Faculty Research

A common design concept of the piezoelectric force sensor, which is to assemble a bump structure from a flat or fine columnar piezoelectric structure or to use a specific type of electrode, is quite limited. In this paper, we propose a new design of cylindrical piezoelectric sensors that can detect multidirectional forces. The proposed sensor consists of four row and four column sensors. The design of the sensor was investigated by the finite element method. The response of the sensor to various force directions was observed, and it was demonstrated that the direction of the force applied to the sensor …

Bioprinted In Vitro Model Of Human Glioblastoma, Rachel Lauren Schwartz

Theses and Dissertations

Glioblastoma multiform (GBM) is one of the most aggressive forms of primary brain tumors. GBM is fast progressing and resistant to treatment, resulting in a low survival rate. Conventional 2-dimensional tissue culture models cannot fully replicate the complexities of cancer lesions that contain multiple cell types and structures (e.g. vessels composed of endothelial cells, cancer cells, normal cells, etc.) as well as an intricate scaffold of proteins comprising the extracellular matrix (ECM). In addition, animal models cannot translate into the clinical disease in patients. Thus, this study has developed a bioprintable organ-on-a-chip (OOAC) model that mimics the important ECM factors …

Artificial Intelligence For Helicopter Safety: Head Pose Estimation In The Cockpit, Eric William Feuerstein

Theses and Dissertations

The recent impact of deep learning algorithms and their major breakthroughs on various aspects of our lives has led to the idea to investigate the application of these algorithms in different problem spaces. One of the novel areas of investigation is the aviation and air traffic control domain; as it offers a prime opportunity to enhance safety within the aviation community. Of particular importance to this community is improving the safety of rotorcraft operations, as this segment of the aviation industry is subject to a higher fatal accident rate than other segments of the industry. The improvement of safety for …

The Effects Of Relational And Social Behaviors Exhibited By Construction Project Team Members On Relationship Quality And Project Outcomes, James Ogechi Kereri

LSU Doctoral Dissertations

Relational and social behaviors of construction project team members explain team relationships. Whereas relational behaviors have often been studied in construction project team relationships, the current literature is deficient on the social behaviors. The literature review revealed seven relational behaviors (i.e., harmonization of conflict, propriety of means, restraint of power, reliance and expectation, contractual solidarity, flexibility, and reciprocity) and three social behaviors (i.e., past experience, benevolence, and integrity) commonly exhibited by construction project team members. Through a binomial logistic regression, research findings revealed that past experience was a significant (p < 0.01) predictor for five of the seven relational behaviors while benevolence and integrity were each significant (p < 0.01) predictors for three of the seven relational behaviors. Overall, out of the seven relational behaviors, only propriety of means is predicted by all the three social behaviors. Through multinomial regression, the results indicated that there is not enough evidence to show a relationship between the dimensions of relationship quality and project outcomes. However, there is a relationship between relationship embeddedness and project outcomes. Through internal and external validation, the prediction models performed well based on both positive predictive values and negative predictive values.

From a relationship management standpoint, this research introduces relational and …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• Engineering Programs Receive ABET Accreditation

The Use Of Three-Dimensional Conjugate Cfd To Enhance Understanding Of, And To Verify, Multi-Modal Heat Transfer In Dynamic Laboratory Test Walls, Rakshit D. Muddu, Timothy Patrick O'Leary, Ronan Hogan, Anthony James Robinson, Aimee Byrne

Articles

This work describes the use of conjugate computational fluid dynamics (C-CFD) to simulate controlled laboratory based dynamic heat transfer tests on building components. This study proposes that conjugate CFD simulation can be used to evaluate the influence of combined convective and conductive heat transfer in multi-state building components. To this end, a solid wall and cavity wall were tested with a Calibrated Hotbox and subject to variable temperature conditions leading to combined convective and conductive heat transfer. The varying temperature of the heat source was monitored and used as the input boundary condition in the simulation model, which included a …

Predicting Mortar Compressive Strength Using Hydcem, Ewoma Ogoro, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

The compressive strength of mortar is a significant property that will influence its performance in concrete or masonry. Being able to accurately model and predict the mortar compressive strength would be of great benefit to suppliers and end users alike that could possibly reduce the need for multiple physical testing. A section of the original HYDCEM cement hydration model (amoungst others) has been partitioned to focus on predicting the compressive strength of Portland cement and cement-limestone mortars, entitled HYDCEM_CompressiveStrength. The model uses the cement/binder oxide composition along with other inputs to predict the compressive strength development over time. This paper …

Conceptual Study Of A Real-Time Hybrid Simulation Framework For Monopile Offshore Wind Turbines Under Wind And Wave Loads, Wei Song, Chao Sun, Yanhui Zuo, Vahid Jahangiri, Yan Lu, Qinghua Han

Faculty Publications

As an attractive renewable energy source, offshore wind plants are becoming increasingly popular for energy production. However, the performance assessment of offshore wind turbine (OWT) structure is a challenging task due to the combined wind-wave loading and difficulties in reproducing such loading conditions in laboratory. Real-time hybrid simulation (RTHS), combining physical testing and numerical simulation in real-time, offers a new venue to study the structural behavior of OWTs. It overcomes the scaling incompatibilities in OWT scaled model testing by replacing the rotor components with an actuation system, driven by an aerodynamic simulation tool running in real-time. In this study, a …

Improvements In Optical Trap Displays, R. Wesley Rogers

Theses and Dissertations

This thesis improves on the design of the Optical Trap Display (OTD), presented in 2018 [1]. Contributions include: real time animation; single beam, multiparticle suspension, point primitive anisotropic scattering, and virtual image approximation. First, real time animation was demonstrated on the OTD for the first time in full color at up to 30Hz refresh. Second, multi-particle systems allow for scaling of the display by a multiplicative factor, potentially up to orders of magnitude greater than the first OTD. Third, anisotropic scattering of point primitives was shown for individual suspended particles and multiple simultaneously suspended particles. Fourth, virtual images have been …

Rectus Femoris Hyperreflexia Contributes To Stiff-Knee Gait After Stroke, Tunc Akbas, Kyoungsoon Kim, Kathleen Doyle, Kathleen Manella, Robert Lee, Patrick Spicer, Maria Knikou, James Sulzer

Publications and Research

Background: Stiff-Knee gait (SKG) after stroke is often accompanied by decreased knee flexion angle during the swing phase. The decreased knee flexion has been hypothesized to originate from excessive quadriceps activation.However, it is unclear whether hyperreflexia plays a role in this activation. The goal of this study was to establish the relationship between quadriceps hyperreflexia and knee flexion angle during walking in post-stroke SKG.

Methods: The rectus femoris (RF) H-reflex was recorded in 10 participants with post-stroke SKG and 10 healthy controls during standing and walking at the pre-swing phase. In order to attribute the pathological neuromodulation to quadriceps muscle …

Evaluation Of Standard And Semantically-Augmented Distance Metrics For Neurology Patients, Daniel B. Hier, Jonathan Kopel, Steven U. Brint, Donald C. Wunsch, Gayla R. Olbricht, Sima Azizi, Blaine Allen

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Patient distances can be calculated based on signs and symptoms derived from an ontological hierarchy. There is controversy as to whether patient distance metrics that consider the semantic similarity between concepts can outperform standard patient distance metrics that are agnostic to concept similarity. The choice of distance metric can dominate the performance of classification or clustering algorithms. Our objective was to determine if semantically augmented distance metrics would outperform standard metrics on machine learning tasks.

Methods: We converted the neurological findings from 382 published neurology cases into sets of concepts with corresponding machine-readable codes. We calculated patient distances by …

Fault-Tolerant Capability Of Star Connected Symmetrical Six-Phase Induction Machine With Single And Two Isolated Neutrals, Wan Noraishah Wan Abdul Munim

Student Works (2020-2029)

Traditionally, electrical machines have been designed to operate with single- or three phase power supplies. In the early stage of power electronics development, three-phase machine suffers problems such as high torque ripple due to low order harmonics during six-step switching and limited current handling capacity of the power switches. This has motivated the use of multiphase machines which is capable of mitigating the aforementioned issues. The revival of multiphase machine research is mainly motivated by the need for more reliable drive systems. The vector space decomposition (VSD) model is used for a healthy multiphase machine as the basis for control …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Water Cutoff Curtain Technology Of Open-Pit Coal Mine Based On Low Strength Impermeable Concrete, Cao Haidong, Miao Hechao, Chi Zan, Gao Sihua

Coal Geology & Exploration

The concrete underground continuous wall has the advantages of convenient construction, reliable quality, good impermeability and so on. It is widely used in water conservancy, hydropower, foundation pit support, subway and other impermeability projects. The materials used are both plastic concrete and rigid concrete. In the water-cutting curtain project of an open-pit coal mine in Inner Mongolia, according to its engineering geological and hydrogeological characteristics, a kind of low-strength(8-10 MPa) impermeable(P6 grade) concrete was developed as the wall casting material, which water/cementitious materials ratio is 0.68, sand ratio is 45%, For 1 m³ of concrete, the content of each …

Inspection Method And Analysis Of The Effect Of Water Cutoff Curtain In Open-Pit Coal Mine, Wang Hai, Peng Wei, Cao Haidong, Wang Li

Coal Geology & Exploration

In order to reduce the water drainage of the studied open-pit mine, a curtain wall was constructed to cut off the river supply on the north side. According to the site construction conditions, four technologies were applied to construct the water cutoff curtain, such as the low-strength impermeable concrete underground continuous wall, HDPE impermeable film, ultra-high pressure angular variable speed jet grouting, and occluding pile. To test the effect of water cutoff curtain in the open-pit coal mine during construction, four surrounding well tests were carried out for three kinds of water cutoff curtain technologies, including low-strength impermeable concrete underground …

Relationship Between Ndvi And Hydromet Factors In Grassland Area Of Open-Pit Coal Mine, Zhang Yan, Huang Xuanming, Chen Shi, Shi Bingxing

Coal Geology & Exploration

The groundwater level of an open-pit coal mine in the grassland area of the east Inner Mongolia has been decreasing continuously under the condition of long-term drainage. In order to study whether the growth of vegetation around the mining area was affected by the decline of groundwater level, the NDVI method was used to analyze the change trend of vegetation index in the study area from 2013 to 2019. Based on the joint entropy theory, the mutual information between NDVI and different meteorological and hydrological elements(temperature, rainfall and groundwater depth)were calculated, and the main influencing factors of vegetation growth were …

Biogas Production And Variation Of The Chemical Composition Of The High Temperature Water Extract Of Lignite, Ren Hengxing, He Huan, Liu Fangjing, Wang Meilin, Guo Xin, Chen Linyong, Zhao Han, Yuan Xuefang, Guan Jiadong, Yue Lijiao

Coal Geology & Exploration

The interaction process between microorganism and coal is complicated. In order to deeply analyze the function and change rule of organic matter in coal in the process of biological gas production, taking Yima lignite and methanogens preserved in laboratory as research objects, the gas production characteristics of water-soluble organic matter of lignite and its chemical composition change before and after gas production were studied. The water-soluble organic components of Yima lignite obtained by deionized water extraction at 70℃ and the extraction residue were used as substrates for biogas production. High performance liquid chromatography-mass spectrometry (HPLC-MS), gas chromatography(GC) and gas chromatography-mass …

Overburden Failure Simulation Under Double Coal Seams Mining In A Coal Mine In North Shaanxi Province, Sun Xueyang, Zhang Qi, Li Cheng, Zhang Lei

Coal Geology & Exploration

Under the conditions of multi-seam mining, the overburden failure of coal seams has unique characteristics, which affects the mine production arrangement. Taking a mine in northern Shaanxi Province as an example, based on the geological and mining conditions of the mine, the influence of double-seam mining on overburden rock damage was analyzed by using the method of similar material simulation experiment and numerical simulation. The results show that the height of the caving zone and the height of the fractured zone in the overburden of coal seam obtained by using similar material simulation and numerical simulation with different widths of …

Spatial Distribution Of Soil Nutrients In Reclamation Dump Sites Based On Subdivision Idw, Zhao Yanling, Zhao Bincheng, Wang Xin, Xiao Wu, Liu Huifang

Coal Geology & Exploration

Accurately grasping the spatial distribution of soil nutrients is of great significance for evaluating the soil quality of reclamation dumps and formulating corresponding reclamation measures. The general interpolation method of the complex terrain of the dump site has a poor prediction effect. The northern dump of Shengli No.1 open-pit mine in Xilinhot, Inner Mongolia was selected as an example in the paper. The soil nutrients(available nitrogen, available potassium, available phosphorus and organic matter) were spatially interpolated using the inverse distance weighting method based on terrain partitioning, and compared with the conventional inverse distance weighting method and kriging interpolation method. The …

Model And Selection Criterion Of Zonal Preact Grouting To Prevent Mine Water Disasters Of Coal Floor Limestone Aquifer In North China Type Coalfield, Dong Shuning, Guo Xiaoming, Liu Qisheng, Wang Hao, Nan Shenghui, Zheng Shitian, Wang Yuhang

Coal Geology & Exploration

In order to promote the development of zonal preact grouting technology and establish a system of the technology to prevent mine water disasters of coal floor aquifer, the authors analyze and summarize the coal seam occurrence and hydrogeological conditions of the Carboniferous-Permian coalfields in China, starting from the engineering systematicity, focusing on the three main factors of drilling conditions, grouting layer selection and drilling technology in the engineering of zonal preact grouting to prevent mine water disasters of coal floor aquifer. The model of zonal preact grouting to prevent mine water disasters of coal floor aquifer is established, which can …

Integrated Monitoring Technology Of Water Inrush From Coal Seam Floor And Its Application, Duan Jianhua

Coal Geology & Exploration

Karst water damage in floor is a common problem in North China type coalfield. Because of its characteristics of concealment and emergency, the prevention and control of water is faced with huge problems and challenges, monitoring and early warning technology of floor water inrush has become a necessary measure in the process of the safe production in coal mines. The formation and occurrence of floor water disaster have a process of evolution from conception, development to occurrence. In this process, the corresponding water inrush symptoms will be released in different stages of the floor crack and apparent resistivity of the …

Water Absorption Characteristics And Their Influence On The Mechanical Properties Of Longmaxi Formation Shale In Northeastern Chongqing, Liu Hong, Xu Fenglin, Chen Qiao, Zhu Honglin, Su Degui, Feng Kelai

Coal Geology & Exploration

A certain amount of casing deformation occurs during the shale reservoir fracturing. There is a certain amount of clay minerals in shale, and after contacting with water-based fracturing fluid, it will show the same expansion characteristics and strength weakening effect as mudstone, which will increase the casing external load. Aiming at the Longmaxi Formation shale in the northeast of Chongqing, the self-absorption and swelling characteristics of shale under different solution systems are studied by physical experiments to analyze the effect of shale hydration on its rock mechanical properties. The results show that the water absorption of shale has a logarithmic …

Development Characteristics Of Freezing Temperature Field Of Coastal Soft Soil Strata, Chen Junhao, Zhuang Yan, Chen Bijian, Zhao Zhenwei, Wang Qiyun

Coal Geology & Exploration

In order to research the temperature fields and development law of freezing in the construction of connected aisle in coastal soft soil stratum, based on connected aisle between Luoxiu road station and Baise road station of Shanghai subway Line 15, the thickness and average temperature of frozen curtain, and the freezing process were analyzed. The temperature fields and development law of freezing were predicted by the three-dimensional numerical model of the connected aisle and the temperature data which were analyzed. The results show that the inherent pressure in soft soil causes initial pressure in the pressure relief hole. A lot …

Collapse Column Identification Method Based On Seismic Waveform Indication Inversion And Its Application, Wan Zhaofei, Guo Zenghu, Wang Peng, Tang Meizhen, Han Tianbao, Liu Liangqiong

Coal Geology & Exploration

During the CBM exploration and development, the collapse column is one of the important factors restricting the exploration effectiveness of coalbed methane. Therefore, the effective identification of collapse column is of great significance for the improvement of CBM exploration. The previous identification methods are based on the discontinuity of the in-phase axis of seismic reflection caused by collapse column. In this paper, the collapse column is innovatively regarded as a kind of geological anomaly, and the identification and prediction of the collapse column are attempted by means of waveform indication inversion. Firstly, through the analysis of logging data and geological …

Layer-Penetrating Staged Fracturing Law Of Horizontal Wells Within Roof Of Coal Seams Under Stress Interference, Xu Yaobo

Coal Geology & Exploration

Layer-penetrating fracturing is the key link to improve production in horizontal well within roof, and stress interference has important influence on layer-penetrating segmental fracturing effect in the horizontal well within roof. Therefore, the layer-penetrating segmental fracturing numerical model of horizontal well within roof is set up, the influence law of fracture propagation on stress interference to layer-penetrating segmental fracturing is studied. The results show that:the rock mechanics parameters, the interval distance and the fracturing construction method are the three important factors affecting the intersegment disturbance of the horizontal well within roof. As the Poisson's ratio of the coal seam goes …

Waveform Cross Correlation-Based Imaging Of Underground Seismic Data While Mining, Zhang Huanlan, Wang Baoli

Coal Geology & Exploration

Seismics while mining is a passive seismic detection technique using a shearer as seismic source. Because the shearer moves unceasingly and excites the continuous signals, the conventional data processing method cannot be applied directly. In the paper a cross-correlation method of segmented waveform was put forward, the effective signal travel time was extracted through the segmentation of the data generated the shear, and then the velocity imaging method was used to image the interior of the working face and the front of the cutting hole. The wave equation was used to carry out the seismics while mining numerical simulation of …

Multi Frequency Perspective Fine Detection Of Radio Wave For Thin Coal Areas In Fully Mechanized Coal Face, Wu Rongxin, Shen Guoqing, Wang Hanqing, Xiao Yulin

Coal Geology & Exploration

The large area of thin coal area in the fully mechanized coal mining face is difficult to be detected accurately by the single frequency perspective detection of radio wave, which seriously affects the efficient and safe production of coal face. In order to detect the occurrence of thin coal area more precisely, a method of multi frequency perspective detection of radio wave is put forward. Taking coalface 1610A of Zhangji mine of Huaihe Energy Group as the research object, according to the geological conditions, four frequency(0.088, 0.158, 0.365 and 0.965 MHz) perspective detection are selected to delineate the thin coal …