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Full-Text Articles in Engineering

Pressure Swing Adsorption Separation Of H2s/Co2/Ch4 Gas Mixtures With Molecular Sieves 4a, 5a, And 13x, Howell H. Heck, Merilyn L. Hall, Rudy Dos Santos, Manolis M. Tomadakis Jul 2018

Pressure Swing Adsorption Separation Of H2s/Co2/Ch4 Gas Mixtures With Molecular Sieves 4a, 5a, And 13x, Howell H. Heck, Merilyn L. Hall, Rudy Dos Santos, Manolis M. Tomadakis

Mechanical and Civil Engineering Faculty Publications

Pressure swing adsorption experiments were carried out for the separation of equimolar mixtures of carbon dioxide and methane containing small amounts of hydrogen sulfide, utilizing 4A, 5A, and 13X molecular sieves. High-purity methane of zero or nearly zero hydrogen sulfide concentration was produced in the adsorption stage with 13X and 5A sieves, at high product recovery rates; high-purity carbon dioxide was obtained with the same sieves in the desorption stage. Zeolite 4A was found capable of raising considerably the hydrogen sulfide concentration in the accumulated desorption product (vs. the adsorption feed) at high recovery rates too. Adsorption selectivity values derived …


Two-Stage Concrete As A Sustainable Production, Hakim Salem Abdelgader, Ali Said Ahmed El-Baden, H. A. Abdurrahman, A. S.M. Abdul Awal Feb 2018

Two-Stage Concrete As A Sustainable Production, Hakim Salem Abdelgader, Ali Said Ahmed El-Baden, H. A. Abdurrahman, A. S.M. Abdul Awal

Mechanical and Civil Engineering Faculty Publications

Two-stage concrete (TSC) is a sustainable concrete which is produced by forcing a flowable cement grout mixture through the voids of a skeletal mass made of compacted preplaced aggregates. From the technical and economic aspects, TSC is particularly useful for construction and repair of concrete structures especially foundations, underwater construction, nuclear reactors, concrete dams, heritage structures and in constructions with closely spaced reinforcement. TSC differs from ordinary concrete in that it contains a higher proportion of stone aggregate and the aggregate stays in point-to-point contact as placed. Thus, the mechanical characteristics of the TSC in failure conditions are distinctly different …


Evaluation Of Elastic Modulus Of Fiber-Reinforced Concrete, Nakin Suksawang, Salam Wtaife, Ahmed Alsabbagh Jan 2018

Evaluation Of Elastic Modulus Of Fiber-Reinforced Concrete, Nakin Suksawang, Salam Wtaife, Ahmed Alsabbagh

Mechanical and Civil Engineering Faculty Publications

This paper determines the effect of discrete fibers on the elastic modulus of concrete and cement composites. Five types of discrete fibers consisting of steel, polypropylene, macro-polyolefin, polyvinyl alcohol (PVA), and basalt fibers were investigated. Results show that discrete fibers had little effect on elastic modulus for fiber-reinforced concrete (FRC) with coarse-to-fine aggregate ratio (C/S) greater than 1. However, for FRC with C/S smaller than 1 and fiber-reinforced cement composites (FRCCs), discrete fibers reduced the elastic modulus. Accordingly, a new elastic modulus equation is proposed to better estimate the elastic modulus of FRC with a maximum fiber volume fraction of …


Extraction Of Phase-Resolved Wave Data From X-Band Radar Imagery, Alexandra Simpson Jan 2018

Extraction Of Phase-Resolved Wave Data From X-Band Radar Imagery, Alexandra Simpson

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Typically, phase-resolved measurements of the sea surface are limited to single-point time series from in situ sensors, or arrays of multiple in situ sensors. The deployment of such devices is costly and time intensive, and the wave data they provide is limited in its spatial coverage and directional accuracy. Several remote sensing options, including optical video and X-Band marine radars, offer the possibility of full 2D reconstruction of the phase-resolved directional sea on spatial scales of kilometers. Ocean waves are visible in radar imagery as the ubiquitous backscatter from short wind ripples is modulated by the longer gravity waves. However, …


Estimation Of Submarine Groundwater Discharge Into The Indian River Lagoon, Ashok Pandit, N. Ali, H. Heck, K. Mamoua Jan 2016

Estimation Of Submarine Groundwater Discharge Into The Indian River Lagoon, Ashok Pandit, N. Ali, H. Heck, K. Mamoua

Mechanical and Civil Engineering Faculty Publications

A calibrated and validated finite difference numerical model was used to estimate the spatial and temporal distribution of the Meteoric Groundwater Discharge (MGWD) and Submarine Groundwater Discharge (SGD) into a coasted estuary known as the Indian River Lagoon (IRL) at two transects. Specifically, this paper describes the methodology used to determine: a) the quantity of MGWD originating from the mainland and the barrier island, b) the spatial distribution of the SGD into the IRL, c) the groundwater salinity and hydraulic head distribution below the IRL, and d) the regional flow directions of the MGWD and the Oceanic Groundwater Discharge (OGWD) …


Modeling Long-Term Deformations Of Unbound Pavement Materials Using The Miniaturized Pressuremeter Creep Data, A. M. Shaban, P. J. Consentino Jan 2016

Modeling Long-Term Deformations Of Unbound Pavement Materials Using The Miniaturized Pressuremeter Creep Data, A. M. Shaban, P. J. Consentino

Mechanical and Civil Engineering Faculty Publications

This research was undertaken to study the predictive capability of the pressuremeter test for characterizing in situ creep behavior of unbound pavement layers. Although the creep potential of granular pavement materials is less pronounced than fine-grained soils, consideration of actual creep deformations in the pavement evaluation process will improve long-term pavement performance. In this investigation, the long-term deformations determined from laboratory one-dimensional creep tests were compared with those investigated by field pressuremeter tests. The pressuremeter test consisted of inflating a cylindrical probe incrementally up to a given stress level, and then maintaining the pressure constant for a 5-min single stage. …


Damping Of Seismic Vibrations Of A 3d Asymmetrical Building Model With Multiple Tmd’S, Jean-Paul Pinelli, Kai Chen, Hector Gutierrez, Rasvan Rusovici Jul 2014

Damping Of Seismic Vibrations Of A 3d Asymmetrical Building Model With Multiple Tmd’S, Jean-Paul Pinelli, Kai Chen, Hector Gutierrez, Rasvan Rusovici

Mechanical and Civil Engineering Faculty Publications

In this paper, the authors investigate the control of the seismic response of a three dimensional asymmetrical tier-building model, with a combination of three tuned mass dampers (TMD) located on the upper floor of the building. The 3D frame model represents a 3-story steel building designed for the SAC project in Los Angeles, California. All the dynamic analyses of the 3D structure are performed in ANSYS. The frequencies of the three TMD's and excitations are tuned to the appropriate fundamental frequencies of the model. The optimal number and location of the TMD's on the top floor are investigated, to reduce …


Pencel Pressuremeter Testing To Determining P-Y Curves For Laterally Loaded Deep Foundations, Messaoud Farid, Nouaouria Md Salah, Paul J. Cosentino Jan 2013

Pencel Pressuremeter Testing To Determining P-Y Curves For Laterally Loaded Deep Foundations, Messaoud Farid, Nouaouria Md Salah, Paul J. Cosentino

Mechanical and Civil Engineering Faculty Publications

The pressuremeter used was essentially the PENCEL pressuremeter (PPMT), manufactured by ROCTEST, Inc. This paper offers a description of the equipment, testing procedure, theory to obtain parameters of the ground and to develop the p-y curves for laterally loaded piles. From PPMT data reduced to graphs of pressure versus volume, soil parameters including the lift-off pressure, the initial elastic and reload moduli, and the limit pressure were determined. Methods developed to determine p-y curves from pressuremeter and dilatometer (DMT) test. P-y curves are used in the analysis to represent lateral soil-pile interaction. The pressuremeter offers an almost ideal in-situ modelling …


Work-Of-Indentation As A Means To Characterize Indenter Geometry And Load-Displacement Response Of A Material, Kaushal K. Jha, Shuo Zhang, Nakin Suksawang, Ton-Lo Wang, Arvind Agarwal Jan 2013

Work-Of-Indentation As A Means To Characterize Indenter Geometry And Load-Displacement Response Of A Material, Kaushal K. Jha, Shuo Zhang, Nakin Suksawang, Ton-Lo Wang, Arvind Agarwal

Mechanical and Civil Engineering Faculty Publications

Normalized indentation works, referred to as the total and elastic energy constants, have been shown to be effective in the representation and analysis of experimental load-displacement data. However, their physical meaning, influencing factors, variation range and relationships with other nanomechanical quantities are not precisely known. In this study, the load-displacement data obtained as a result of simulations of elastic and elastoplastic indentations are extensively analyzed to enhance our understanding concerning these two energy based parameters. It has been shown that while the total energy constant describes the state of an indenter tip and the type of contact regime, the elastic …


Influence Of Optical Fiber Coating Damage In The Light Transmissivity Characteristics Of Microbend Sensors, Franz Campero, Paul J. Cosentino, David C. Fleming, Edward H. Kalajian, Barry G. Grossman Jun 2005

Influence Of Optical Fiber Coating Damage In The Light Transmissivity Characteristics Of Microbend Sensors, Franz Campero, Paul J. Cosentino, David C. Fleming, Edward H. Kalajian, Barry G. Grossman

Mechanical and Civil Engineering Faculty Publications

A laboratory testing and engineering modeling study was completed to determine the influence of fiber optic coating damage caused by microbend contact on the performance of microbend sensors developed based on relatively low cost single-sided microbending technique using a multimode optical fiber. A testing method was designed, developed and implemented to determine the loads that caused optical fiber glass-coating debonding and coating fracture. Finite Element models of the fiber-deformer system were developed to study the failure modes and predict the stresses that caused this failure. Loads and displacements predicted by Finite Element models were found to be in good agreement …


Volumetric Exchanges Between A Managed Marsh And A Coastal Estuary, Ashok Pandit, John H. White, Antonis A. Kakoullis, Satish B. Akula, James R. David Jan 1997

Volumetric Exchanges Between A Managed Marsh And A Coastal Estuary, Ashok Pandit, John H. White, Antonis A. Kakoullis, Satish B. Akula, James R. David

Mechanical and Civil Engineering Faculty Publications

The dominant term in the estimation of net flux calculation, between a marsh and a source of tidal water is often the exchange of water. The purpose of this study was to provide a description of the methodology used to estimate the volumetric exchange of surface waters between a managed marsh and the Indian River Lagoon during the managed and unmanaged periods. The paper also documents the simplifying assumptions that had to be made to estimate the exchanges both during the managed and unmanaged period. These assumptions had to be made either because the data were limited mainly due to …


Groundwater Seepage Into The Indian River Lagoon At Port St Lucie, Ashok Pandit, Clovis Clovis El-Khazen Jan 1990

Groundwater Seepage Into The Indian River Lagoon At Port St Lucie, Ashok Pandit, Clovis Clovis El-Khazen

Mechanical and Civil Engineering Faculty Publications

A finite element program, GROSEEP, was developed to estimate the groundwater seepage from the surficial aquifer into Indian River lagoon along a selected cross-section in Port St. Lucie, Florida. The model is a general purpose model and can be used at other cross-sections. Model results using a single layer indicate that groundwater seepage could be an important freshwater source into the lagoon. Sensitivity analysis using a three-layer model predicted that among other parameters the presence of windows in the clay layers could significantly affect seepage rates into the lagoon.