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Articles 1051 - 1080 of 1721

Full-Text Articles in Engineering Science and Materials

Mechanical Properties And Permeability Of Sand Casting Moulds With Eggshells Binder, Maryam Sharifi Jebeli Sharifi Jebeli, Wahyu Kurnianto, Wahono Wahono Jul 2018

Mechanical Properties And Permeability Of Sand Casting Moulds With Eggshells Binder, Maryam Sharifi Jebeli Sharifi Jebeli, Wahyu Kurnianto, Wahono Wahono

Journal of Mechanical Engineering Science and Technology (JMEST)

This research aimed to analyse whether or not eggshell could be a potential addition to sand mould composition as a binding material together with bentonite. Different amounts of eggshell material, i.e. 4%, 7%, 10% and 3%, were added to each sample. This study was a type of pre-experimental design called the one-shot case study. Among all sand moulds under study, sample 3 10% ES in dry conditions had the highest tensile, compressive and shear strengths of 0.09 Kg/cm2, 3.11 Kg/cm2 and 1.13 Kg/cm2, respectively. The results of the permeability test with heat treatment at 110˚C for 60 minutes showed that …


Properties Of Cassava Starch Based Bioplastic Reinforced By Nanoclay, Nanang Eko Wahyuningtiyas, Heru Suryanto Jul 2018

Properties Of Cassava Starch Based Bioplastic Reinforced By Nanoclay, Nanang Eko Wahyuningtiyas, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Synthetic Synthetic plastic is chemical materials which cause severe environmental problems. Incinerating plastic waste leads to release of hazardous gases, which is not good for humans. Bioplastic can help reduce the dependence on fossil fuels and petroleum, that bioplastic can solve the problem of synthetic plastic use. This research aims to define the properties of the cassava starch-based bioplastic reinforced by nanoclay. Methods were experimental with bioplastic component of cassava starch, glycerol as plasticizer and nanoclay as reinforcement. The bioplastic was analyzed using XRD, tensile test, moisture absorption, biodegradability, and compared with another bioplastic. The results show that the addition …


Near-Field Heat Transfer Enabled Nanothermomechanical Memory And Logic Devices, Sidy Ndao, Mahmoud Elzouka Jul 2018

Near-Field Heat Transfer Enabled Nanothermomechanical Memory And Logic Devices, Sidy Ndao, Mahmoud Elzouka

Department of Mechanical and Materials Engineering: Faculty Publications

A thermomechanical memory / logic device is disclosed . In embodiments , the thermomechanical device includes a first thermally controlled terminal ( e . g . , hot terminal ) ; a second thermally controlled terminal ( e . g . , cool terminal / base ) ; a stem or other structure that can be thermally expanded connected to the cool terminal ; and a thermal conductive head coupled to the stem . The head can exchange heat with the hot terminal . The stem and head are between the first thermally controlled terminal and the second thermally controlled …


Prevascularization Of 3d Printed Bone Scaffolds By Bioactive Hydrogels And Cell Co-Culture, Mitchell Kuss, Shaohua Wu, Ying Wang, Jason B. Untrauer, Wenlong Li, Jung Yul Lim, Bin Duan Jul 2018

Prevascularization Of 3d Printed Bone Scaffolds By Bioactive Hydrogels And Cell Co-Culture, Mitchell Kuss, Shaohua Wu, Ying Wang, Jason B. Untrauer, Wenlong Li, Jung Yul Lim, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated …


Smart Bandage For Monitoring And Treatment Of Chronic Wounds, Pooria Mostafalu, Ali Tamayol, Rahim Rahimi, Manuel Ochoa, Akbar Khalilpour, Gita Kiaee, Iman K. Yazdi, Sara Bagherifard, Mehmet R. Dokmeci, Babak Ziaie, Sameer R. Sonkusale, Ali Khademhosseini Jul 2018

Smart Bandage For Monitoring And Treatment Of Chronic Wounds, Pooria Mostafalu, Ali Tamayol, Rahim Rahimi, Manuel Ochoa, Akbar Khalilpour, Gita Kiaee, Iman K. Yazdi, Sara Bagherifard, Mehmet R. Dokmeci, Babak Ziaie, Sameer R. Sonkusale, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Chronic wounds are a major health concern and they affect the lives of more than 25 million people in the United States. They are susceptible to infection and are the leading cause of nontraumatic limb amputations worldwide. The wound environment is dynamic, but their healing rate can be enhanced by administration of therapies at the right time. This approach requires real-time monitoring of the wound environment with on-demand drug delivery in a closed-loop manner. In this paper, a smart and automated flexible wound dressing with temperature and pH sensors integrated onto flexible bandages that monitor wound status in real-time to …


Interface Structure And Deformation Mechanisms Of Mg/Nb Multilayers, Xinyan Xie Jul 2018

Interface Structure And Deformation Mechanisms Of Mg/Nb Multilayers, Xinyan Xie

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Magnesium (Mg) and its alloys, as the lightest structural materials, are very attractive for a range of weight sensitive applications, such as aircraft engine, transportation industry and so on. However, their further applications are limited due to the weak properties, such as the low strength and poor ductility. In recent years, advanced techniques aiming at the modification of the microstructures, have been developed to promote the properties of Mg and its alloys, such as modifying the texture, refining the grain size, forming the intermetallic phase, and introducing the interfaces or stacking faults into the systems. Constructing Mg/Nb multilayers, which introduces …


Migration Resistance Of Esophageal Stents: The Role Of Stent Design, Hozhabr Mozafari, Pengfei Dong, Shijia Zhao, Yonghua Bi, Xinwei Han, Linxia Gu Jun 2018

Migration Resistance Of Esophageal Stents: The Role Of Stent Design, Hozhabr Mozafari, Pengfei Dong, Shijia Zhao, Yonghua Bi, Xinwei Han, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Objective: Stenting is one of the major treatments for malignant esophageal cancer. However, stent migration compromises clinical outcomes. A flared end design of the stent diminishes its migration. The goal of this work is to quantitatively characterize stent migration to develop new strategies for better clinical outcomes.

Methods: An esophageal stent with flared ends and a straight counterpart were virtually deployed in an esophagus with asymmetric stricture using the finite element method. The resulted esophagus shape, wall stress, and migration resistance force of the stent were quantified and compared.

Results: The lumen gain for both the flared stent and the …


Me-Em Enewsbrief, June 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Jun 2018

Me-Em Enewsbrief, June 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Analysis Of The Low-Cycle Fatigue Behavior Of Silicone Rubber For Biomedical Balloons, Chase Cooper Jun 2018

Analysis Of The Low-Cycle Fatigue Behavior Of Silicone Rubber For Biomedical Balloons, Chase Cooper

Materials Engineering

The development of a medical drug delivery device that allows for the deployment drugs into the adventitial tissue of blood vessels requires the inflation of a silicone elastomer. The inflated silicone must be able to consistently endure multiple loading cycles without failing so that the device can operate reliably. There are multiple methods of processing the silicone for the device and the goal of this study is to examine the effect of the various processing methods on the characteristics of the silicone. The Dynamic Mechanical Analysis Machine (DMA) is used to model the conditions of the device’s application by performing …


System And Method For Controlling Operations Of Air - Conditioning System, Mouhacine Benosman, Petros Boufounos, Boris Kramer, Piyush Grover May 2018

System And Method For Controlling Operations Of Air - Conditioning System, Mouhacine Benosman, Petros Boufounos, Boris Kramer, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

A method controls an operation of an air - conditioning system generating airflow in a conditioned environment . The method updates a model of airflow dynamics connecting values of flow and temperature of air conditioned during the operation of the air - conditioning system . The model is updated interactively iteratively to reduce an error between values of the airflow determined according to the model and values of the airflow measured during the operation . Next , the method models the airflow using the updated model and controls the operation of the air - conditioning system using the model .


Preliminary Investigation Of Tensile Strength And Impact Characterization Of Cementitious Composite Incorporating Carbon Nanotubes, Robabeh Jazaei May 2018

Preliminary Investigation Of Tensile Strength And Impact Characterization Of Cementitious Composite Incorporating Carbon Nanotubes, Robabeh Jazaei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cement has been largely used in the construction industry, specifically as a matrix for concrete. Recently, a new generation of cement-based composite that greatly increases mechanical properties is replacing conventional concrete. With periodic advances in the field, researchers considered particles with high-aspect ratios such as Carbon Nanotubes (CNTs) to reinforce cement matrices. Although there is not much literature to draw upon in research, some research on improving the tensile strength of cementitious composite incorporating with CNTs does exist. However, there had been no evidence of investigation into impact strength until this study.

Most papers presented examined the effect of multi-walled …


Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli May 2018

Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli

Electronic Theses and Dissertations

Metal Additive Manufacturing (AM) is increasingly being used to make functional components. One of the barriers for AM components to become mainstream is the difficulty to certify them. AM components can have widely different properties based on process parameters. Improving an AM processes requires an understanding of process-structure-property correlations, which can be gathered in-situ and post-process through nondestructive and destructive methods. In this study, two metal AM processes were studied, the first is Ultrasonic Additive Manufacturing (UAM) and the second is Laser Powder Bed Fusion (L-PBF). The typical problems with UAM components are inter-layer and inter-track defects. To improve the …


Concomitant Crystallization In Propylene/Ethylene Random Copolymer With Strong Flow At Elevated Temperatures, Lirong Zheng, Lucia Fernandez-Ballester, Gerrit W. M. Peters, Zhe Ma May 2018

Concomitant Crystallization In Propylene/Ethylene Random Copolymer With Strong Flow At Elevated Temperatures, Lirong Zheng, Lucia Fernandez-Ballester, Gerrit W. M. Peters, Zhe Ma

Department of Mechanical and Materials Engineering: Faculty Publications

Flow-induced crystallization of α- and γ-phases was studied for a propylene/ethylene random copolymer with 3.4 mol % ethylene at two high temperatures of 132 and 142 °C by combining a pressure-driven slit flow device with real-time synchrotron wide-angle X-ray diffraction. At 132 °C, it was found that both α- and γ-phases were generated at shear stresses ranging from 0.091 to 0.110 MPa and that the γ-phase always appeared later than the α-phase. However, for 142 °C and the same stresses, only the α-phase formed. Only upon cooling the partially crystallized copolymer did the γ-phase emerge. The lack of γ-crystals obtained …


In Situ Defect Detection Using Three Color Spectroscopy In Laser Powder Bed Additive Manufacturing, Andrew Drieling Apr 2018

In Situ Defect Detection Using Three Color Spectroscopy In Laser Powder Bed Additive Manufacturing, Andrew Drieling

The University Honors Program

Additive Manufacturing (AM) provides a way to create parts that would be extremely difficult or impossible with conventional manufacturing processes. However, AM also introduces defects, which are detrimental to the mechanical performance. These defects are potentially unknown until post-processing inspection and testing, wasting time and resources on an unusable part or initiating unexpected failure. Historically, spectroscopy has successfully been used for in situ monitoring of laser welding, using changing parameters in the generated plume to predict defects. In situ monitoring using a visible spectrometer for fabrication of Alloy 718 on a test bed laser powder bed fusion system is performed. …


Rare Earth - Free Permanent Magnetic Material, Laura H. Lewis, Jeffrey E. Shield, Katayun Barmak Viziri Apr 2018

Rare Earth - Free Permanent Magnetic Material, Laura H. Lewis, Jeffrey E. Shield, Katayun Barmak Viziri

Department of Mechanical and Materials Engineering: Faculty Publications

The invention provides rare earth - free permanent magnetic materials and methods of making them . The materials can be used to produce magnetic structures for use in a wide variety of commercial applications , such as motors , generators , and other electromechanical and electronic devices . Magnets fabricated using the materials can be substituted for magnets requiring rare earth elements that are costly and in limited supply . The invention provides two different types of magnetic materials . The first type is based on an iron - nickel alloy that is doped with one or more doping elements …


Method Of Fabricating A Continuous Nanofiber, Yuris Dzenis Apr 2018

Method Of Fabricating A Continuous Nanofiber, Yuris Dzenis

Department of Mechanical and Materials Engineering: Faculty Publications

A method of fabricating a continuous nanofiber is described . The method includes preparing a solution of one or more polymers and one or more solvents and electrospinning the solution by discharging the solution through one or more liquid jets into an electric field to yield one or more continuous nanofibers . The electrospinning process ( i ) highly orients one or more polymer chains in the one or more continuous nanofibers along a fiber axis of the one or more continuous nanofibers , and ( ii ) suppresses polymer crystallization in the one or more continuous nanofibers . The …


Method For Data - Driven Learning - Based Control Of Hvac Systems Using High - Dimensional Sensory Observations, Amir-Massoud Farahmand, Saleh Nabi, Piyush Grover, Daniel Nikolaev Nikovski Apr 2018

Method For Data - Driven Learning - Based Control Of Hvac Systems Using High - Dimensional Sensory Observations, Amir-Massoud Farahmand, Saleh Nabi, Piyush Grover, Daniel Nikolaev Nikovski

Department of Mechanical and Materials Engineering: Faculty Publications

A controller for controlling an operation of an air - conditioning system conditioning an indoor space includes a data input to receive state data of the space at multiple points in the space , a memory to store a code of a reinforcement learning algorithm and a history of the state data and a history of control commands having been applied to the air - conditioning system , wherein the history of the control commands is associated with the state data and history of rewards , a processor coupled to the memory determines a value function outputting a cumulative value …


An Evaluation Of Induction Heating In Healthcare Food Industry, Barrett Alexander Hampton Apr 2018

An Evaluation Of Induction Heating In Healthcare Food Industry, Barrett Alexander Hampton

Masters Theses & Specialist Projects

This thesis addresses the problem healthcare facilities are having in maintaining proper food temperatures while transporting meals to patients after food has left the kitchen area. Induction heat has been a known method for generating heat for many years. The commercial food industry currently uses this technology, which is beginning to appear in the residential sector as well because of developments made by manufacturers. This study focuses on the top commercial brand models of induction heaters and the supporting materials currently used to create heat sources to maintain food temperatures in hospitals and long term care facilities.

The research in …


The Effect Of Poly (Glycerol Sebacate) Incorporation Within Hybrid Chitin–Lignin Sol–Gel Nanofibrous Scaffolds, Tuerdimaimaiti Abudula, Lassaad Gzara, Giovanna Simonetti, Ahmed Alshahrie, Numan Salah, Pierfrancesco Morganti, Angelo Chianese, Afsoon Fallahi, Ali Tamayol, Sidi A. Bencherif, Adnan Memic Mar 2018

The Effect Of Poly (Glycerol Sebacate) Incorporation Within Hybrid Chitin–Lignin Sol–Gel Nanofibrous Scaffolds, Tuerdimaimaiti Abudula, Lassaad Gzara, Giovanna Simonetti, Ahmed Alshahrie, Numan Salah, Pierfrancesco Morganti, Angelo Chianese, Afsoon Fallahi, Ali Tamayol, Sidi A. Bencherif, Adnan Memic

Department of Mechanical and Materials Engineering: Faculty Publications

Chitin and lignin primarily accumulate as bio-waste resulting from byproducts of crustacean crusts and plant biomass. Recently, their use has been proposed for diverse and unique bioengineering applications, amongst others. However, their weak mechanical properties need to be improved in order to facilitate their industrial utilization. In this paper, we fabricated hybrid fibers composed of a chitin–lignin (CL)-based sol–gel mixture and elastomeric poly (glycerol sebacate) (PGS) using a standard electrospinning approach. Obtained results showed that PGS could be coherently blended with the sol–gel mixture to form a nanofibrous scaffold exhibiting remarkable mechanical performance and improved antibacterial and antifungal activity. The …


Me-Em Enewsbrief, March 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Mar 2018

Me-Em Enewsbrief, March 2018, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


The Positive Role Of Curcumin-Loaded Salmon Nanoliposomes On The Culture Of Primary Cortical Neurons, Mahmoud Hasan, Shahrzad Latifi, Cyril J.F. Kahn, Ali Tamayol, Rouhollah Habibey, Elodie Passeri, Michel Linder, Elmira Arab-Tehrany Mar 2018

The Positive Role Of Curcumin-Loaded Salmon Nanoliposomes On The Culture Of Primary Cortical Neurons, Mahmoud Hasan, Shahrzad Latifi, Cyril J.F. Kahn, Ali Tamayol, Rouhollah Habibey, Elodie Passeri, Michel Linder, Elmira Arab-Tehrany

Department of Mechanical and Materials Engineering: Faculty Publications

Curcumin (diferuloylmethane) is a natural bioactive compound with many health-promoting benefits. However, its poor water solubility and bioavailability has limited curcumin’s biomedical application. In the present study, we encapsulated curcumin into liposomes, formed from natural sources (salmon lecithin), and characterized its encapsulation efficiency and release profile. The proposed natural carriers increased the solubility and the bioavailability of curcumin. In addition, various physico-chemical properties of the developed soft nanocarriers with and without curcumin were studied. Nanoliposome-encapsulated curcumin increased the viability and network formation in the culture of primary cortical neurons and decreased the rate of apoptosis.


Ureteral Tunnel Length Versus Ureteral Orifice Configuration In The Determination Of Ureterovesical Junction Competence: A Computer Simulation Model, Carlos A. Villanueva, J. Tong, Carl A. Nelson, Linxia Gu Feb 2018

Ureteral Tunnel Length Versus Ureteral Orifice Configuration In The Determination Of Ureterovesical Junction Competence: A Computer Simulation Model, Carlos A. Villanueva, J. Tong, Carl A. Nelson, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Introduction The long-held belief that a ureteral re-implant tunnel should be five times the diameter of the ureter, as proposed by Paquin in 1959, ignores the effect of the orifice on the occurrence of reflux. In 1969, Lyon proposed that the shape of the ureteral orifice (UO) is more important than the intravesical tunnel. However, both theories missed quantitative evidence from principles of physics. The goal of the current study was to test Lyon’s theory through numerical models (i.e. to quantify the sensitivity of ureterovesical junction (UVJ) competence to intravesical tunnel length and to the UO).

Materials and methods The …


Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu Feb 2018

Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …


Me-Em 2017-18 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Jan 2018

Me-Em 2017-18 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering Annual Reports

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An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joseph A. Turner, Hani Alanazi, Charles Nguyen Jan 2018

An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joseph A. Turner, Hani Alanazi, Charles Nguyen

Department of Mechanical and Materials Engineering: Faculty Publications

Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To …


Methods, Systems, And Devices For Surgical Access And Procedures, Shane M. Farritor, Mark Rentschler, Amy Lehman, Stephen R. Platt, Jeff Hawks Jan 2018

Methods, Systems, And Devices For Surgical Access And Procedures, Shane M. Farritor, Mark Rentschler, Amy Lehman, Stephen R. Platt, Jeff Hawks

Department of Mechanical and Materials Engineering: Faculty Publications

The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices. Certain embodiments include various actuation system embodiments, including fluid actuation systems, drive train actuation systems, and motorless actuation systems. Additional embodiments include a reversibly lockable tube that can provide access for a medical device to a patient's cavity and further provides a reversible rigidity or stability during operation of the device. Further embodiments include various operational components for medical devices, including medical device arm mechanisms that have both axial and rotational movement while maintaining a relatively compact …


Excess Charge-Carrier Induced Instability Of Hybrid Perovskites, Yuze Lin, Bo Chen, Yanjun Fang, Jingjing Zhao, Chunxiong Bao, Zhenhua Yu, Yehao Deng, Peter N. Rudd, Yanfa Yan, Yongbo Yuan, Jinsong Huang Jan 2018

Excess Charge-Carrier Induced Instability Of Hybrid Perovskites, Yuze Lin, Bo Chen, Yanjun Fang, Jingjing Zhao, Chunxiong Bao, Zhenhua Yu, Yehao Deng, Peter N. Rudd, Yanfa Yan, Yongbo Yuan, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Identifying the origin of intrinsic instability for organic–inorganic halide perovskites (OIHPs) is crucial for their application in electronic devices, including solar cells, photodetectors, radiation detectors, and light-emitting diodes, as their efficiencies or sensitivities have already been demonstrated to be competitive with commercial available devices. Here we show that free charges in OIHPs, whether generated by incident light or by current-injection from electrodes, can reduce their stability, while efficient charge extraction effectively stabilizes the perovskite materials. The excess of both holes and electrons reduce the activation energy for ion migration within OIHPs, accelerating the degradation of OIHPs, while the excess holes …


Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini Jan 2018

Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Keratins extracted from human hair have emerged as a promising biomaterial for various biomedical applications, partly due to their wide availability, low cost, minimal immune response, and the potential to engineer autologous tissue constructs. However, the fabrication of keratin-based scaffolds typically relies on limited crosslinking mechanisms, such as via physical interactions or disulfide bond formation, which are time-consuming and result in relatively poor mechanical strength and stability. Here, we report the preparation of photocrosslinkable keratin-polyethylene glycol (PEG) hydrogels via the thiol-norbornene “click” reaction, which can be formed within one minute upon irradiation of visible light. The resulting keratin-PEG hydrogels showed …


An Analysis Of Common Drill Stem Vibration Models, Mohammed F. Al Dushaishi, Runar Nygaard, Daniel S. Stutts Jan 2018

An Analysis Of Common Drill Stem Vibration Models, Mohammed F. Al Dushaishi, Runar Nygaard, Daniel S. Stutts

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Excessive drill stem (DS) vibration while rotary drilling of oil and gas wells causes damages to drill bits and bottom hole assemblies (BHAs). In an attempt to mitigate DS vibrations, theoretical modeling of DS dynamics is used to predict severe vibration conditions. To construct the model, decisions have to be made on which beam theory to be used, how to implement forces acting on the DS, and the geometry of the DS. The objective of this paper is to emphasize the effect of these assumptions on DS vibration behavior under different, yet realistic, drilling conditions. The nonlinear equations of motion …


Optimization Of Microfluidic Particle Separator Geometry Using Computational Fluid Dynamics, Joseph Petersen Jan 2018

Optimization Of Microfluidic Particle Separator Geometry Using Computational Fluid Dynamics, Joseph Petersen

Electronic Theses and Dissertations

Computational fluid dynamics software was used to simulate the motion of circulating tumor cells in a variety of microfluidic cell isolation devices. Design of several novel microfluidic cell isolation devices was aided by viewing streamlines of fluid in devices in simulation. Devices that performed best in simulation used 5-micrometer wide guiding channels to guide cells to the capture location in the device. While these devices performed better than other devices in simulation and captured all particles regardless of position along inlet, experimental results differ from simulation.