Mechanical Engineering Commons^™

Human-Skin-Inspired Adaptive Smart Textiles Capable Of Amplified Latent Heat Transfer For Thermal Comfort, Gunwoo Kim, Calvin Gardner, Kyuin Park, Ying Zhong, Sungho Jin

Mechanical Engineering Faculty Publications

Thermally adaptive textiles (TATs) enable human subjects to attain thermal comfort without energy consumption, which can lead to enormous energy savings on heating, ventilation, and air conditioning (HVAC) in buildings. Herein, TAT structures which respond to the sweat and generate pores by opening an array of flap-shaped pores patterned on the fabric surface are proposed. A moisture-driven self-actuator for flap opening by constructing a bilayer consisting of a hygroscopic layer using polyethylene glycol and cellulose acetate, and a hydrophobic polymer using a polyester type polymer, is used and successfully demonstrated an essentially instant 4 °C apparent temperature cooling performance within …

Collagen Production And Niche Engineering: A Novel Strategy For Cancer Cells To Survive Acidosis In Dcis And Evolve, Mehdi Damaghi, Hidetoshi Mori, Samantha Byrne, Liping Xu, Tingan Chen, Joseph Johnson, Nathan D. Gallant, Andriy Marusyk, Alexander D. Borowsky, Robert J. Gillies

Mechanical Engineering Faculty Publications

Growing tumors are dynamic and nonlinear ecosystems, wherein cancer cells adapt to their local microenvironment, and these adaptations further modify the environment, inducing more changes. From nascent intraductal neoplasms to disseminated metastatic disease, several levels of evolutionary adaptations and selections occur. Here, we focus on one example of such an adaptation mechanism, namely, “niche construction” promoted by adaptation to acidosis, which is a metabolic adaptation to the early harsh environment in intraductal neoplasms. The avascular characteristics of ductal carcinoma in situ (DCIS) make the periluminal volume profoundly acidic, and cancer cells must adapt to this to survive. Based on discovery …

Spontaneous Formation Of Sub-4 Nm Nanocrystalline Alloy Via Polymorphic Phase Transformation, Ying Zhong, Chunqing Wang, Jin Wang, Huiwen Ma, Sriram Krishnamoorthy, Vladislav Paley, Zijian Weng, Sungho Jin

Mechanical Engineering Faculty Publications

A new phase-transformation-induced path to spontaneous formation of extreme nanograin structure is reported. In-situ-heating-mode-microscopy exhibited a substantial grain-growth of Cu6Sn5. During cooling, the grain-growth continued, but it spontaneously switched to grain-refinement mode on phase transformation through ∼180 °C from η-Cu6Sn5 to η’-Cu6Sn5, ending up with an extremely small nanograin size of ∼2.5 nm. The cooling cycling always restores the nanograin size regardless of thermal exposure history, making this to be the first demonstration to stabilize the nanograin with its own spontaneous behavior. The Young’s Modulus was significantly reduced by ∼×3, and the elongation was remarkably increased by …

Analysis Of Human Behavior For Robot Design And Control, Tyagi Ramakrishnan, Seok Hun Kim, Kyle B. Reed

Mechanical Engineering Faculty Publications

The combined gait asymmetry metric (CGAM) provides a method to synthesize human gait motion. The metric is weighted to balance each parameter’s effect by normalizing the data so all parameters are more equally weighted. It is designed to combine spatial, temporal, kinematic, and kinetic gait parameter asymmetries. It can also combine subsets of the different gait parameters to provide a more thorough analysis. The single number quantifying gait could assist robotic rehabilitation methods to optimize the resulting gait patterns. CGAM will help define quantitative thresholds for achievable balanced overall gait asymmetry. The study presented here compares the combined gait parameters …

Edge Geometry Effects On Resonance Response Of Electroplated Cylindrical Ni/Pzt/Ni Magnetoelectric Composites, Vladislav Yakubov, Lirong Xu, Alex A. Volinsky, Lijie Qiao, De’An Pan

Mechanical Engineering Faculty Publications

Trilayer Ni/PZT/Ni cylindrical magnetoelectric (ME) composites were prepared by electrodeposition, a process, which creates sub-millimeter raised edges due to current concentration near sharp points. The ME response in both axial and vertical modes was measured with the edges, with only outer edges removed, and with both outer and inner edges removed. The ME voltage coefficient improved at resonance by 40% and 147% without the edges in the vertical and axial modes, respectively. The observed improvements in three different samples were only present at the ME resonance and no changes were detected outside of the ME resonance. Mechanical quality factor at …

Modified Qigong Breathing Exercise For Reducing The Sense Of Hunger On An Empty Stomach, Alexander P. Voroshilov, Alex A. Volinsky, Zhixin Wang, Elena V. Marchenko

Mechanical Engineering Faculty Publications

Background: The aims of this study were to determine whether a modified Qigong breathing exercise can reduce the sense of hunger and identify possible mechanisms.

Methods: The results from the test group, which performed the exercise, are compared with the control group, which performed deep breathing. Intestinal pressure measurements, stomach pH monitoring, and participant surveys were used for assessment.

Results: Stomach pH was increased by 3 (0.2) and intestinal pressure was reduced by 12 (0.5) mm Hg in the experimental group and did not change significantly in the control group. The study provides strong evidence that the exercise can significantly …

Sputtering Power Effects On Growth And Mechanical Properties Of Cr2alc Max Phase Coatings, Muhammad Naveed, Aleksei Obrosov, Andrzej Zak, Wlodzimierz Dudzinski, Alex A. Volinsky, Sabine Weiß

Mechanical Engineering Faculty Publications

Coating growth and mechanical properties of nanolamellar Cr₂AlC coatings at various sputtering power were investigated in the present study. Cr₂AlC coating was deposited on the IN 718 superalloy and (100) Si wafers by DC magnetron sputtering at different sputtering powers. The structure and properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nanoindentation. It was found that coatings had columnar structure with nanocrystalline substructure. Deposition rate increased with the sputtering power. XRD results showed the presence of the Cr₂AlC MAX phase, intermetallic AlCr₂ and Cr_{7 …}

Eigenstress Model For Electrochemistry Of Solid Surfaces, Hongxin Ma, Xilin Xiong, Panpan Gao, Xi Li, Yu Yan, Alex A. Volinsky, Yanjing Su

Mechanical Engineering Faculty Publications

Thermodynamic analysis and molecular dynamics simulations were conducted to systematically study the size-dependent electrochemical response of solids. By combining the generalized Young-Laplace equation with the popular Butler-Volmer formulation, the direct influence of surface stress on solid film electrochemical reactions was isolated. A series of thermodynamic formulas were developed to describe the size-dependent electrochemical properties of the solid surface. These formulas include intrinsic surface elastic parameters, such as surface eigenstress and surface elastic modulus. Metallic films of Au, Pt, Ni, Cu and Fe were studied as examples. The anodic current density of the metal film increased, while the equilibrium potential decreased …

Dynamic Recrystallization Behavior And Processing Map Of The Cu–Cr–Zr–Nd Alloy, Yi Zhang, Huili Sun, Alex A. Volinsky, Baohong Tian, Kexing Song, Zhe Chai, Ping Liu, Yong Liu

Mechanical Engineering Faculty Publications

Hot deformation behavior of the Cu–Cr–Zr–Nd alloy was studied by hot compressive tests in the temperature range of 650–950 °C and the strain rate range of 0.001–10 s⁻¹ using Gleeble-1500D thermo-mechanical simulator. The results showed that the flow stress is strongly dependent on the deformation temperature and the strain rate. With the increase of temperature or the decrease of strain rate, the flow stress significantly decreases. Hot activation energy of the alloy is about 404.84 kJ/mol and the constitutive equation of the alloy based on the hyperbolic-sine equation was established. Based on the dynamic material model, the processing map …

On Event-Triggered Adaptive Architectures For Decentralized And Distributed Control Of Large-Scale Modular Systems, Ali Albattat, Benjamin C. Gruenwald, Tansel Yucelen

Mechanical Engineering Faculty Publications

The last decade has witnessed an increased interest in physical systems controlled over wireless networks (networked control systems). These systems allow the computation of control signals via processors that are not attached to the physical systems, and the feedback loops are closed over wireless networks. The contribution of this paper is to design and analyze event-triggered decentralized and distributed adaptive control architectures for uncertain networked large-scale modular systems; that is, systems consist of physically-interconnected modules controlled over wireless networks. Specifically, the proposed adaptive architectures guarantee overall system stability while reducing wireless network utilization and achieving a given system performance in …

Functional Performance Differences Between The Genium And C-Leg Prosthetic Knees And Intact Knees, Michael J. Highsmith, Jason T. Kahle, Rebecca M. Miro, M. E. Cress, Derek J. Lura, William S. Quillen, Stephanie Carey, Rajiv V. Dubey, Larry J. Mengelkoch

Mechanical Engineering Faculty Publications

Microprocessor prosthetic knees (MPKs) have advanced technologically, offering new features to decrease impairment and activity limitations for persons with transfemoral amputation (TFA). The Genium knee is functionally untested, and functional differences between it and intact knees are unknown. This study sought to determine whether Genium use improves functional performance compared with the C-Leg. A randomized experimental crossover design was used, with a cross-section of five nonamputee controls for comparison to nor­mal. Twenty community-ambulating persons with TFA were trained and tested for accommodation with study components. All subjects (n = 25) were assessed using the Continuous-Scale Physical Functional Performance-10 (CS-PFP10) …

Microfocusing At The Pg1 Beamline At Flash, S. Dziarzhytski, N. Gerasimova, Rene Goderich, T. Mey, M. Rübhausen, F. Siewert, H. Weigelt, G. Brenner

Mechanical Engineering Faculty Publications

The Kirkpatrick-Baez (KB) refocusing mirror system installed at the PG1 branch of the plane-grating monochromator beamline at the soft X-ray/XUV free-electron laser in Hamburg (FLASH) is designed to provide tight aberration-free focusing down to 4 µm × 6 µm full width at half-maximum (FWHM) on the sample. Such a focal spot size is mandatory to achieve ultimate resolution and to guarantee best performance of the vacuum-ultraviolet (VUV) off-axis parabolic double-monochromator Raman spectrometer permanently installed at the PG1 beamline as an experimental end-station. The vertical beam size on the sample of the Raman spectrometer, which operates without entrance slit, defines and …

User Involvement In The Partner Program Of The Educational Social Network, Ilya V. Osipov, Alex A. Volinsky, Anna Y. Praskikova

Mechanical Engineering Faculty Publications

The paper describes experiments to attract active online system users to the partner program. The objective is to grow the number of users by involving existing system users in viral mechanics. Several examples of user motivation are given, along with the specific interface implementations and viral mechanics. Viral K-factor was used as the metrics for the resulting system growth assessment. Specific examples show both positive and negative outcomes. Growth of the target system parameters is discussed.

Diamond And Related Nanomaterials For Mems/Nems Applications, Rakesh K. Joshi, Ashok Kumar

Mechanical Engineering Faculty Publications

No abstract provided.

Fabrication And Characterization Of Zno Nanowire Arrays With An Investigation Into Electrochemical Sensing Capabilities, Jessica Weber, Sathyaharish Jeedigunta, Ashok Kumar

Mechanical Engineering Faculty Publications

ZnO nanowire arrays were grown on a Si (100) substrate using the vapor-liquid-solid (VLS) method. ZnO nanowires were characterized by XRD, SEM, bright field TEM, and EDS. They were found to have a preferential orientation along the -axis. The as-prepared sample was functionalized with glucose oxidase by physical adsorption. FTIR was taken before and after functionalization to verify the presence of the attached enzyme. Electrochemical measurements were performed on the nanowire array by differential pulse voltammetry in the range of -0.6 to 0.4 V. The nanoarray sensor displayed high sensitivity to glucose in the range of 1.0 x 10^{-4 …}