Mechanical Engineering Commons^™

Critères De Stabilité Des Échelles Et Des Escabeaux, Bertrand Galy

Rapports de recherche scientifique

Les chutes de hauteur sont encore aujourd’hui une des principales causes d’accident au Québec, et la deuxième cause en termes de coûts sur la période 2010 – 2012, avec une moyenne de 397 millions de dollars par année. Selon la CNESST, les statistiques de lésions impliquant les échelles, que ce soit en construction ou en établissement, montrent une augmentation au fil des ans (période de 2007 à 2012) et sur la période 2009 à 2013, 20 % des lésions dues à une chute de hauteur ont été causées par une chute à partir d’une échelle.

Un des principaux critères affectant …

Advances In The Application Of Biomimetic Surface Engineering In The Oil And Gas Industry, Yanbao Guo, Zheng Zhang, Siwei Zhang

Friction

Friction is widespread in almost every field in the oil and gas industry, and it is accompanied by huge energy losses and potential safety hazards. To deal with a series of questions in this regard, biomimetic surfaces have been developed over the past decades to significantly reduce economic losses. Presently, biomimetic surface engineering on different scales has been successfully introduced into related fields of the oil and gas industry, such as drill bits and the inner surfaces of pipes. In this review, we focused on the most recent and promising efforts reported toward the application of a biomimetic surface in …

Rubber Plunger Surface Texturing For Friction Reduction In Medical Syringes, Haytam Kasem, Harel Shriki, Lihi Ganon, Michael Mizrahi, Kareem Abd-Rbo, Abraham J. Domb

Friction

Friction is a genuine issue in the use of many medical devices involving rubbery materials such as plungers in medical syringes. This paper presents a new direction for the reduction of friction in medical syringes based on surface texturing of the rubber plunger. The specimens were prepared by casting poly(vinylsiloxane) (PVS) rubber into a pre-fabricated negative template obtained by 3D printing. Friction tests were performed on a home-made test-rig. It was clearly shown that friction resistance can be considerably manipulated when using textured plungers.

Erosive Wear Properties Of Za-27 Alloy-Based Nanocomposites: Influence Of Type, Amount, And Size Of Nanoparticle Reinforcements, Aleksandar Vencl, Ilija Bobić, Biljana Bobić, Kristina Jakimovska, Petr Svoboda, Mara Kandeva

Friction

Metal matrix nanocomposites (MMnCs) comprise a metal matrix filled with nanosized reinforcements with physical and mechanical properties that are very different from those of the matrix. In ZA-27 alloy-based nanocomposites, the metal matrix provides ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2 wt.%, 0.3 wt.%, and 0.5 wt.%) and sizes (25 nm, 50 nm, and 100 nm) of nanoparticles were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 …

Friction And Wear Behaviors Of Mos2-Multi-Walled-Carbon-Nanotube Hybrid Reinforced Polyurethane Composite Coating, Zhaozhu Zhang, Mingming Yang, Junya Yuan, Fang Guo, Xuehu Men

Friction

MoS2-multi-walled-carbon-nanotube (MWCNT) hybrids containing two-dimensional MoS2 and one-dimensional MWCNTs were synthesized through a one-step hydrothermal reaction. X-ray-diffraction and transmission-electron-microscopy results demonstrated that MoS2 nanosheets were successfully synthesized, and uniformly anchored on the MWCNTs' surfaces. Furthermore, the effects of the MoS2-MWCNT hybrids on the tribological performances of polyurethane composite coatings were investigated using a UMT-2MT tribo-tester. Friction and wear test results revealed that the friction coefficient and wear rate of a 3 wt% MoS2-MWCNT-1 filled polyurethane composite coating were reduced by 25.6% and 65.5%, respectively. The outstanding tribological performance of the MoS2-MWCNT-1 reinforced polyurethane composite coating was attributed to the excellent …

Sliding Friction Of Shale Rock On Dry Quartz Sand Particles, Huijie Zhang, Shuhai Liu, Huaping Xiao

Friction

The sliding friction of rock, involving all kinds of particles at the contact surface, is relevant to many problems, ranging from those in artificial engineering to earthquake dynamics. In this work, the frictional performance of the shale rock-dry quartz sand contact was investigated using a self-developed testing device. The study showed that the coefficient of friction of the contact increases with nominal stress and that the corresponding friction force increases approximately linearly with nominal stress, which is directly related to the contact stress between each single sand particle and rock shale. An overall dynamic coefficient, γ, reflecting the response of …

Friction Predication On Pin-To-Plate Interface Of Ptfe Material And Steel, Zhuming Bi, Donald W. Mueller

Friction

In this paper, the friction behavior at a pin-to-plate interface is investigated. The pin and plate are made of Polytetrafluoroethylene (PTFE) and steel, respectively, and there is a reciprocating motion at the interface. Governing mathematical models for the relations of design variables and frictions are investigated, and a general procedure is proposed to solve the developed models and predict the friction forces at the interface subjected to given test conditions. Novel models have been developed to represent intrigued friction behaviors affected by various factors such as pin geometrics and finishes, lubrication conditions, and reciprocating speed. The test data from experiments …

Significant Friction Reduction Of High-Intensity Pulsed Ion Beam Irradiated Wc-Ni Against Graphite Under Water Lubrication, Gaolong Zhang, Yuechang Wang, Ying Liu, Xiangfeng Liu, Yuming Wang

Friction

Two types of commercial WC-Ni samples were irradiated with the High-intensity pulsed ion beam (HIPIB). Both the surface characteristics and tribo-characteristics of the non-irradiated and irradiated WC-Ni samples, sliding against graphite under water lubrication, were compared. Quite low steady friction coefficients (approximately of 0.02) of the irradiated WC-Ni were observed. The surface topographies and components were investigated. The quite low friction of the irradiated WC-Ni samples was ascribed to the higher fluid retention capability of the latter and the tribofilm formed during sliding.

Metal-Containing Nanomaterials As Lubricant Additives: State-Of-The-Art And Future Development, Igor E. Uflyand, Vladimir A. Zhinzhilo, Victoria E. Burlakova

Friction

This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years.

Experimental Study On The Tribo-Chemical Smoothening Process Between Self-Mated Silicon Carbide In A Water-Lubricated Surface-Contact Reciprocating Test, Le Jin, Herbert Scheerer, Georg Andersohn, Matthias Oechsner, Dieter Hellmann

Friction

Silicon carbide (SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water …

Water-Based Superlubricity In Vacuum, Chen Xiao, Jinjin Li, Lei Chen, Chenhui Zhang, Ningning Zhou, Tao Qing, Linmao Qian, Jiyang Zhang, Jianbin Luo

Friction

This study achieved water-based superlubricity with the lubrication of H3PO4 solution in vacuum (highest vacuum degree <10-4 torr) for the first time by performing a pre-running process in air before running in vacuum. The stable water-based superlubricity was sustainable in vacuum (0.02 torr) for 14 h until the test was stopped by the user for non-experimental factor. A further analysis suggested that the superlubricity may be attributed to the phosphoric acid-water network formed in air, which can efficiently lock water molecules in the liquid lubricating film even in vacuum owing to the strong hydrogen bond interaction. Such capability to lock water is strongly affected by the strength of hydrogen bond and environmental conditions. The realization of water-based superlubricity with H3PO4 solution in vacuum can lead to its application in space environment.

Tribological Performance Of Novel Nickel-Based Composite Coatings With Lubricant Particles, Ignacio Tudela, Andrew J. Cobley, Yi Zhang

Friction

The present study is focused on the evaluation of the tribological performance of novel Ni/hBN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound. Lubricated and non-lubricated scratch tests were performed on both novel composite coatings and on standard Ni deposits used as a benchmark coating to have an initial idea of the effect of the presence of particles within the Ni matrix. Under lubricated conditions, the performance of the Ni/hBN composite coating was very similar to the benchmark Ni coating, whereas the Ni/WS2 behaved quite differently, as the latter did not only show …

Numerical Analysis Of Time-Varying Wear With Elastic Deformation In Line Contact, Wanglong Zhan, Ping Huang

Friction

Wear is an important factor for failures of mechanical components. Current research on wear is mainly focused on experiments while the numerical simulation of wear is hardly used owing to the complexities of the wear process. Explaining the effect of friction on the wear process is important, as it will lead to a deeper understanding of the evolution of wear. This study proposed a numerical method to expound the wear process in the contact between an elastic cylinder and a half-space simulating the ring-block tester. There are two difficulties during the calculation; one is that the contact shapes vary with …

Optimal Control Of Active Nematics, Michael M. Norton, Piyush Grover, Michael F. Hagan, Seth Fraden

Department of Mechanical and Materials Engineering: Faculty Publications

In this work we present the first systematic framework to sculpt active nematic systems, using optimal control theory and a hydrodynamic model of active nematics. We demonstrate the use of two different control fields, (i) applied vorticity and (ii) activity strength, to shape the dynamics of an extensile active nematic that is confined to a disk. In the absence of control inputs, the system exhibits two attractors, clockwise and counterclockwise circulating states characterized by two co-rotating topological þ1 2 defects. We specifically seek spatiotemporal inputs that switch the system from one attractor to the other; we also examine phase-shifting perturbations. …

Modifying The Surface Chemistry And Nanostructure Of Carbon Nanotubes Facilitates The Detection Of Aromatic Hydrocarbon Gases, John N. Hodul, Allison K. Murray, Nikhil F. Carneiro, Joseph R. Meseke, Jacob Morris, Xinping He, Dimitry Zemlyanov, George T.-C. Chiu, James E. Braun, Jeffrey F. Rhoads, Bryan W. Boudouris

Mechanical Engineering Faculty Research and Publications

The benzene, toluene, and xylene (BTX) compounds currently utilized in many building materials and paints have been linked to deleterious health effects, and thus, monitoring the presence of these compounds is of increasing importance with respect to public health. As such, there is a critical need for next-generation low-cost, selective, and sensitive indoor BTX sensors. Current BTX detection systems require multicomponent, complex devices or require high power input to achieve BTX detection at meaningful concentrations, but this long-standing paradigm can be altered through the introduction of tailored nanomaterials. Specifically, we demonstrate a selective BTX resonant mass sensor platform that leverages …

Characterization And Performance Of Minimum Quantity Lubricants In Through-Tool Drilling, Amla Patil, Jay Raval, Tim Bangma, Immanuel Edinbarough, Bruce Tai, David Stephenson, Suleiman Obeidat, Wayne Nguyen Hung

Manufacturing & Industrial Engineering Faculty Publications

This study characterized airborne microdroplet diameters and size distribution from two commercially available lubricants A and B for internal minimum quantity lubrication (MQL). The effects of air pressure, oil channel size, physical properties of lubricants on the resultant microdroplets and through-tool MQL drilling performance were studied. Airborne microdroplet diameters were highly sensitive to the coolant channel sizes and air pressure. Cluster method was used to divide microdroplets into smaller clusters for comparison. Experimental data show that the average airborne microdroplet of lubricant B was larger than that of lubricant A at different air pressures and channel sizes. The contact angle …

The Energy And Exergy Of Light With Application To Societal Exergy Analysis.Pdf, Matthew K. Heun, Zeke Marshall, Emmanuel Aramendia, Paul E. Brockway

University Faculty Publications and Creative Works

Lighting provides an indispensable energy service, illumination. The field of societal exergy analysis considers light (andmany other energy products) to be enablers of economic growth, and lighting contributes a non-negligible proportion of total useful exergy supplied to modern economies. In societal exergy analysis, the exergetic efficiency of electric lamps is central to determining the exergy contribution of lighting to an economy. Conventionally, societal exergy practitioners estimate the exergetic efficiency of lamps by an energy efficiency, causing confusion and, sometimes, overestimation of exergetic efficiency by a factor as large as 3. In response, we use recent results from the fields of …

Microfluidic Systems With Embedded Cell Culture Chambers For High Throughput Biological Assays, Arian Jaberi, Amir Monemian Esfahani, Fariba Aghabaglou, Jae Sung Park, Sidy Ndao, Ali Tamayol, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

The ability to generate chemical and mechanical gradients on chips is important both for creating biomimetic designs or enabling high-throughput assays. However, there is still a significant knowledge gap in the generation of mechanical and chemical gradients in a single device. In this study, we developed gradient-generating microfluidic circuits with integrated microchambers to allow cell culture and to introduce chemical and mechanical gradients to cultured cells. A chemical gradient is generated across the microchambers, exposing cells to a uniform concentration of drugs. The embedded microchamber also produces a mechanical gradient in the form of varied shear stresses induced upon cells …

Experimental Investigation Of Transverse Loading Behavior Of Ultra-High Molecular Weight Polyethylene Yarns, Karan Deepak Shah, Subramani Sockalingam

Faculty Publications

Ultra-high molecular weight polyethylene (UHMWPE) Dyneema^® SK-76 fibers are widely used in personnel protection systems. Transverse ballistic impact onto these fibers results in complex multiaxial deformation modes such as axial tension, axial compression, transverse compression, and transverse shear. Previous experimental studies on single fibers have shown a degradation of tensile failure strain due to the presence of such multi-axial deformation modes. In this work, we study the presence and effects of such multi-axial stress-states on Dyneema^® SK-76 yarns via transverse loading experiments. Quasi-static transverse loading experiments are conducted on Dyneema^® SK-76 single yarn at different starting angles …

Efficient Trajectory Optimization For Curved Running Using A 3d Musculoskeletal Model With Implicit Dynamics, Marlies Nitschke, Eva Dorschky, Dieter Heinrich, Heiko Schlarb, Bjoern M. Eskofier, Anne D. Koelewijn, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Trajectory optimization with musculoskeletal models can be used to reconstruct measured movements and to predict changes in movements in response to environmental changes. It enables an exhaustive analysis of joint angles, joint moments, ground reaction forces, and muscle forces, among others. However, its application is still limited to simplified problems in two dimensional space or straight motions. The simulation of movements with directional changes, e.g. curved running, requires detailed three dimensional models which lead to a high-dimensional solution space. We
extended a full-body three dimensional musculoskeletal model to be specialized for running with directional changes. Model dynamics were implemented implicitly …

Analytical And Experimental Study Of Fatigue-Crack-Growth Ae Signals In Thin Sheet Metals, Roshan Joseph, Victor Giurgiutiu

Faculty Publications

The acoustic emission (AE) method is a very popular and well-developed method for passive structural health monitoring of metallic and composite structures. AE method has been efficiently used for damage source detection and damage characterization in a large variety of structures over the years, such as thin sheet metals. Piezoelectric wafer active sensors (PWASs) are lightweight and inexpensive transducers, which recently drew the attention of the AE research community for AE sensing. The focus of this paper is on understanding the fatigue crack growth AE signals in thin sheet metals recorded using PWAS sensors on the basis of the Lamb …

Swimming Of Pelagic Snails: Kinematics And Fluid Dynamics, Ferhat Karakas

USF Tampa Graduate Theses and Dissertations

Pteropods (also known as sea butterflies or sea angels), are holoplanktonic marine snails which swim by flapping a pair of extremely flexible wings. The wings are modified from the molluscan foot and the wing motions are supported by the fluid pressure without any rigid support. Sea angels (gymnosome pteropods) are completely naked; in contrast, sea butterflies (thecosome pteropods) have negatively buoyant aragonite shells which vary in geometry and size among different species. Pteropods are seasonally abundant in the ocean, and an important food source for the other zooplanktons, fishes, and whales. Though studies have been conducted regarding their biology, ecology, …

Impact Of Sintering Time And Temperature On Mechanical Properties In Projection Sintering Of Polyamide-12, Justin Nussbaum, Taranjot Kaur, Julie Harmon, Nathan B. Crane

Faculty Publications

In powder bed fusion additive manufacturing (AM), the fusing process is temperature and time dependent. However, little work has been done to understand how different processing temperatures and times might impact the mechanical properties at longer sintering times than are typical in laser sintering (LS) systems. Prior results with projection sintering have shown that heating for longer times (>1s) improves part toughness compared to laser sintering. In this work, Large Area Projection Sintering (LAPS) is used to sinter entire layers of material simultaneously over the course of a few seconds with spatial control of layer temperature. This work evaluates …

Semi Open Partitions: A Defense Strategy For Airborne Disease, Kerrie Marshall, Arik Palileo, Eric A. Schiff

SyracuseCoE

This brief summarizes research on two measures that reduce the risk of transmitting COVID-19 from an infected person to a virus-free individual. Semi-partitioned spaces can reduce airborne disease transmission when combined with a proper ventilation flow pattern in a room. With advanced displacement ventilation risk can be reduced by at least 4 times.

Resistive Switching In Fto/Cuo-Cu2o/Au Memory Devices, Amir Shariffar, Haider Salman, Tanveer A. Siddique, Wafaa Gebril, M. Omar Manasreh

Electrical Engineering Faculty Publications and Presentations

Memristors are considered to be next-generation non-volatile memory devices owing to their fast switching and low power consumption. Metal oxide memristors have been extensively investigated and reported to be promising devices, although they still suffer from poor stability and laborious fabrication process. Herein, we report a stable and power-efficient memristor with novel heterogenous electrodes structure and facile fabrication based on CuO-Cu2O complex thin films. The proposed structure of the memristor contains an active complex layer of cupric oxide (CuO) and cuprous oxide (Cu2O) sandwiched between fluorine-doped tin oxide (FTO) and gold (Au) electrodes. The fabricated memristors demonstrate bipolar resistive switching …

Dynamic Analysis Of Viscoelastic Circular Diaphragm Of A Mems Capacitive Pressure Sensor Using Modified Differential Transformation Method, Dr Olurotimi A. Adeleye, Muritala Yusuf, Oluwaseyi .. Balogun

Karbala International Journal of Modern Science

In this paper, a dynamic analysis of the viscoelastic circular diaphragm of a Micro-Electro-Mechanical System (MEMS) capacitive pressure sensor using the Modified Differential Transformation Method (MDTM) is presented. The MEMS technology has been increasingly used to fabricate sensors and actuators and the MEMS capacitive pressure sensor is emerging in many high-performance applications. The deflection of these sensors diaphragm (plate) depends largely on the material of the diaphragm. In this study, a circular diaphragm of viscoelastic material is modeled using the classical plate theory. The governing differential equation is solved using Modified Differential Transformation Method (MDTM) and the result is validated …

A New Technical Solution For Cleaning The Water Intake Structure Of Pumping Stations From Siltation And Its Experimental Research, M.M. Mukhammadiev, S.R. Juraev

Irrigation and Melioration

The article considers one of the most pressing problems of pumping stations in the irrigation system today, their blurring of the bottom of the water intake (avancamera and water intake chambers), analyzes the existing proposals, designs and technical solutions and their advantages and disadvantages. Given the above advantages and disadvantages, a new design has been proposed for the treatment of water intake structures from turbid sediments with minimal energy and capital expenditures, very cheap and simple to operate and reliable. The design includes a turbid suction pump and a turbid pump, as well as a pulp pipeline. The pressurized water …

Assessing Surface Water Features Using Landsat-8 Oli And Sentinel-1 Satellite Images Case Study Sirdaryo Region, S.M. Muratov, Kh.A. Abdivaitov, Sh.F. Rahmatillayev

Irrigation and Melioration

Water resources have become a very big problem in every part of Uzbekistan for several decades. Water is used not only exclusively for agricultural development, but also for many other purposes, such as industrial and chemical activities. Therefore, it is important to study the properties of surface water objects using optical and microwave satellite images. The Syrdarya region was selected for research. Because in the past, there have been no studies of water bodies using satellite images. The article presents the results of studies on the assessment of water properties from optical and microwave satellite images. In research for optical …

Distribution Of Pressure And Specific Energy In The Twirled Stream For Confusor, A.A. Yangiev, D.S. Adjimuratov

Irrigation and Melioration

Article brings up the advantage of confusor part application in outflow part of vortex spillway, which may be more rational from the point of view of providing non-cavitation operation of flow swirler. Analytical design method and program developed is given of pressure and specific energy for aerated part of swirled flow in vortex spillway confusor part, which match with experimental results, it allows for fast and quite accurate realization of distribution analysis for pressure and specific energy in swirled flow along the length of the confusor for various rates of taper.

Economic Assesment Of The Impact Of Climate Factors On Wheat Yield In Samarkand Region, Sh.B. Babakholov

Irrigation and Melioration

Agricultural production is highly vulnerable to climate shocks and predicted climate consequences may pose severe challenges to the resilience of Uzbek agricultural system, especially in terms of food security and income stability of rural producers. In this context, present study proposed to assess the impact of climate factors, such particular changes in mean temperature and rainfalls on total output of wheat-cultivating farmers in Samarkand region. By considering irrigation source and heterogeneous geography of the region, farmers engaged in wheat production were analyzed in two: upstream and downstream zones using Fixed effect panel approach. The empirical findings of study revealed that, …