bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Experimental Investigation on the Stability of Gel-Like Carbon Dot Based Nanofluids
Authors: Mollick Rahat , Hentges Nicholas , Parveg A. S. M. Sazzad , Zhou Yiqun , Leblanc Roger M. , Ratner Albert 
Published: February 2023

Abstract
Highly photoluminescent gel-like carbon dots (G-CDs) have interesting applications in the fields of bio-sensing, thermofluids, and as photocatalysts to reduce water contaminants. G-CDs have been shown to be nontoxic and environmentally benign while exhibiting interesting characteristics as fluid additives. For additives like G-CDs to be effective, they need to stay suspended in the liquid medium. If they settle to the bottom, the positive benefits are lost, and the high-density lower region can experience adverse effects due to excessive particle loading. Many existing techniques are available to analyze suspension stability. However, most of these techniques are expensive and/or require specialized equipment. Moreover, these methods can be invasive and ultimately end up disturbing the suspension. Furthermore, these methods often focus on understanding the relation between colloidal stability and surface charge development through measuring the zeta potential, an indicator which is reported to be unsuitable while working with higher concentrations of nanomaterial in the colloidal suspension. To overcome the deficiencies of the traditional zetametry experiments, a novel, non-contact, non-invasive, quantitative, and economical experimental setup was deployed in this work to investigate the stability of G-CD nanofluids. The G-CD concentration is kept constant at 3wt%. Decane and small amount of water is used as dispersion media for the nanofluid in this study. Four different water concentrations of 1.5 wt%, 1 wt%, 0.75 wt% and 0.375 wt% are tested in this work. The results show the technique is both effective and inexpensive.
Vibration Control of a Cantilever Beam Using Reduced Model
Authors: Kamalirad Amir Mohamad , Fotouhi Reza , Taghizadeh Mitra 
Published: February 2023

Abstract
One of objectives of the research work here is to actively control vibration of a flexible manipulator’s end-effector. Another objective is to reduce computational cost to control vibration. When the manipulator is in lock configuration, it can be considered as a cantilever beam with base motion. In this paper, finite-element analysis (FEA) is used to obtain natural frequencies (eigenvalues) and mode shapes (eigenvectors) for a cantilever beam. The eigenvectors are translated into uncoupled state space equations, based on balanced realization and Match-DC-Gain model reduction algorithm. Linear quadratic regulator is employed for full and reduced models of the beam. Contribution of this research is on verifying analytical approach (reduced model) with numerical model (FEA). Contribution also includes computational efficiency of the model reduction. Simulation results for vibration suppression of the cantilever beam are obtained and compared with two different models.
Phase-Field Modelling for Crack Evolution of PBX Under Thermomechanical Loadings
Authors: Long Xu , Zhu Jiaqi , Su Yutai , Siow Kim S. , Chen Chuantong 
Published: February 2023

Abstract
Polymer-bonded explosive (PBX), also known as plastic-bonded explosive, is a typical kind of explosive powder with the synthetic polymer bonded together explosive composite materials. It has excellent explosion performance and thus is widely applied in the military and civilian industries. The PBX mechanical properties exhibit high sensitivities to the action of various types of loads, which is closely related to microscopic damage mechanisms within the material. The applied loads vary considerably, with amplitudes ranging from a few MPa to as high as several tens of GPa and durations lasting from the order of μs to ms. The cracking evolution is essential to the PBX applications in a strict control manner. However, PBXs are dangerous energy-bearing materials, and the mechanical experiments to measure their mechanical properties are costly and also challenging. Therefore, theoretical analysis and numerical simulation are anticipated to explore the sensitivities of PBX mechanical properties and also the influence of crack evolution. This paper will simulate numerically the process of work done of PBX explosive gas by fracture phase-field method, which reveals the typical microscopical mechanism of crack evolution and establish a computational model for crack propagation under the coupled thermomechanical effects.
Ammonia for Industrial Combustion
Authors: Londerville Steve , Whelan Matt , Baukal Charles , Gueniche Ali , Haag Michel , Newman Paul 
Published: February 2023

Abstract
Many companies are investigating switching from conventional fossil fuels to “green” fuels such as hydrogen to reduce CO2 emissions. This assumes hydrogen is made by an environmentally-friendly method such as electrolysis using renewable energy. However, there are concerns with hydrogen. For example, it leaks very easily, is extremely flammable, and is more difficult to transport than other fuels.
A potential solution is to use ammonia as an alternative method of supplying hydrogen to a combustion process, assuming it is made in an environmentally-friendly manner. Like H2, ammonia also does not produce any carbon-containing pollutants such as carbon monoxide, carbon dioxide, or soot. It has transport properties like propane, so it is easier to contain and transport than hydrogen.
However, there are some concerns with ammonia. It is a caustic and hazardous chemical with a pungent odor so it must be handled accordingly. It has the potential to generate very high levels of NOx which means a post-treatment system like an SCR may be required. Existing burners may need to be modified or replaced.
While ammonia is a potentially important future green fuel, there are concerns that require attention and further research. This paper compares methane, hydrogen, and ammonia combustion and discusses the advantages and disadvantages of ammonia in particular.
Variation of Sound Directivity From a Supersonic Nacelle
Authors: Sugar Mitchell L. , Slaboch Paul E. 
Published: February 2023

Abstract
The effects of aircraft flight speed and fan face pressure variations on sound propagation from an axisymmetric commercial supersonic engine inlet were studied using numerical methods. A computational fluid dynamics (CFD) model of the inlet was constructed in Ansys Fluent. The results of this model were then used as inputs for the aeroacoustic solver, ACTRAN, and used to calculate far field radiated noise. Using this process, a parametric study was conducted varying two parameters: the approach Mach number from 0.35 to 0.55 in increments of 0.0125, and the fan face back pressures from −10 kPa to −40 kPa in increments of 1 kPa. It was found that variations in free stream Mach number resulted in approximate variations of 2 dB on radiated acoustics while variations in fan face pressure resulted in up to 5 dB of change. These variations were found to be frequency dependent with the largest variations happening over a frequency range of approximately 3 kHz to 5 kHz and again from 6 kHz to 8 kHz. These results indicate combinations of flight speed and fan pressure to avoid in flight to reduce overall noise reaching the ground.
Prediction of Sectional Collapse of Thin-Walled Structure Under Pure Bending by Nonlinear Composite Beam Theory
Authors: Jiang Fang , Yu Wenbin 
Published: February 2023

Abstract
Brazier [1] found that when one dimension of the beam cross-section was relatively smaller than the others, large in-plane displacements over the cross-section might occur, even though the strains could remain very small. Under this circumstance, the so-called Brazier effect refers to the cross-sectional ovalization, which leads to nonlinear bending buckling and collapses. This paper extends the Variational Asymptotic Beam Sectional Analysis (VABS) theory to consider finite cross-sectional deformations. The three-dimensional (3D) continuum is reduced to a one-dimensional (1D) beam analysis and a two-dimensional (2D) cross-sectional analysis featuring both geometric and material nonlinearities without unnecessary kinematic assumptions. The present theory is implemented using the finite element method (FEM) in the VABS code, a general-purpose beam cross-sectional analysis tool. An iterative method is applied to solve the finite warping field for the classical-type model using the Euler-Bernoulli beam theory. The deformation gradient tensor is directly used to deal with finite deformation, various strain definitions, and several types of material laws regarding nonlinear elasticity and progressive damage. Numerical examples demonstrate the capabilities of VABS to predict the sectional collapse of thin-walled structures under pure bending.
Thermal Analysis of a Fiber Optic Cable for a Vertical Farming Application
Authors: Cesmeci Sevki , Islam Mohammad Towhidul , Horowitz Stephen 
Published: February 2023

Abstract
Feeding the existing 7 billion and ever-growing population around the world urges farmers to adopt alternative ways. Research indicates that the demand for alternative farming will only increase as fertile lands become scarcer each and every year. Emerged from this need, “agritecture,” often called vertical farming, has attracted a great deal of attention recently. Vertical farming is centered around growing plants by adopting methods like hydroponic, aeroponic, or aquaponic and staking the layer vertically up to the sky or going deep in the ground. Lighting is the integral component of the vertical farming systems, which can be natural or artificial and should be provided at a specific intensity and spectrum. The world is already in need of energy to tackle the soaring energy demand due to the rising population and industrialization. Researchers have been trying to utilize alternative sources, and the heat and illumination of the sunlight is always the widespread field of interest. In vertical farming, using hybrid solar lighting can also be an appealing approach. However, the fiber optical cable is one of the critical components of this system, which is used to transmit the light to the luminaire. Since this cable plays a vital role in transmitting the power, the exposure of the surface of the cable to different rays from the directed sunlight is of primary concern to avoid any thermal failure. If not designed properly, the temperatures at the inlet of the fiber optical cable can reach to very high values, resulting in both physical and chemical changes in the cable, and in some cases, local burnings. A literature survey revealed that there are only a few studies that dealt with the thermal management of fiber optical cables. In this study, we analyze the thermal behavior of fiber optical cables for a vertical farming application, which was supported by the United States Department of Agriculture SBIR Phase I program. To do that, we adopted a Finite Element Analysis (FEA) based approach. Before carrying out the full simulations, the simulation methodology was verified by replicating an existing study in the literature. Once confirmed, a full parametric sweep analysis was conducted to see the effects of material and geometric properties of the fiber optical cable on the temperature increase at the inlet. This study is novel in the sense that there are no prior studies that targeted the effects of material and geometric properties on the thermal behavior of the fiber optical cables so the users could make the appropriate choices for the cable selection or could custom design their cables for specific lighting conditions. The results were presented and discussed, and future research directions were indicated.
Spatial Pendulum TMD With Two Tuning Frequencies
Authors: Mohamed Waled T. A. , Kashani Ahmad 
Published: February 2023

Abstract
Some structures have different natural frequencies in the two lateral X and Y-directions. Tuned damping of such structures require using either a) the less attractive option of two regular PTMDs each tuned to one of the natural frequencies of the structures’ lateral modes or b) one pendulum TMD with two different tuning frequencies (one for each lateral directions), necessitating two different swinging lengths. Pendulum TMDs with two different tuning frequencies in the two lateral X and Y directions, are realized by constraining the swinging length of the pendulum in one direction but not in the other direction. Such two degree-of-freedom pendulum tuned mass damper, is called Bi-PTMD.
In this work, the dynamics of a two degree-of-freedom pendulum tuned mass damper (Bi-TMD) appended to a structure with two low-frequency, lateral degrees of freedom (representing the first two modes of a tall structure) is studied and the nonlinear differential equations of motion are derived using the Lagrangian mechanics approach. The equations of motion are simplified using small angle and slow motion assumptions.
The system of nonlinear differential equations are numerically simulated in Matlab/Simulink environment and the responses of the structure without and with the pendulum Bi-TMD to a number of different perturbations in the lateral directions are evaluated. The numerical model is verified by comparing its simulation results with the outcomes of SimScape Multibody physical model of the same system.
Hysteresis Effect of Tangential Force Field on Deformation of Single Cell Migrating Between Different Micro-Striped Topography Patterns
Authors: Hashimoto Shigehiro , Yonezawa Hiroki , Kishimoto Kazuya 
Published: February 2023

Abstract
The hysteresis effect of the tangential force field (perpendicular to the cell major axis) on cell activity (deformation, migration) has been studied in vitro. Cell orientation was aligned by microtopography patterns (striped ridgelines; height 0.7 μm, width 3 μm, spacing 3 μm) on the scaffold plane. Three compartments with different angles (0 degrees, 45 degrees, and 90 degrees) between the longitudinal direction of the ridges and the direction of the tangential force field were designed. Osteoblasts (MC3T3-E1; osteoblast precursor cell line derived from mouse calvaria) were used in the experiment. After applying a tangential force field for 5 hours, the position and contour of each cell was tracked by time-lapse microscopic images for 48 hours. Experimental results show that the tangential force field perpendicular to the cell major axis affects subsequent action (deformation, migration) of cells. The effect is maintained for 48 hours even if the cell moves to different areas of the topography pattern.
Experimental Research on the Corrosion and Heat Transfer Characteristics of HCl-H2O Vapors Outside a 3-D Finned Tube
Authors: Huang Ying , Chen Yuxuan , Zhang Weilong , Ding Yudong , Liao Qiang , Cheng Min 
Published: February 2023

Abstract
Hydrochloric acid (HCl) corrosion in the overhead condensation system of crude distillation units is a common occurrence in refinery worldwide. The HCl corrosion can not only reduce the heat transfer performance of the heat exchanger, but also lead to the thinning of the heat exchanger wall, and even cause perforation and leakage. Therefore, it is necessary to study the corrosion and heat transfer characteristics of the heat exchanger under this condition, in order to improve the heat transfer performance and safety. In this paper, a 3-D finned tube with high heat exchange efficiency was used to study the corrosion and heat transfer characteristics with the moist air containing HCl outside it. The effects of different H2O volume fraction and HCl volume fraction on the HCl dew point of the 3D finned tube were studied. The corresponding HCl dew point prediction formula was fitted by the experimental data. In addition, the heat transfer characteristics of 3-D finned tube with HCl-H2O vapors outside was studied. The experimental results showed that the HCl dew point increased with an increase of the H2O volume fraction and HCl volume fraction. Furthermore, for the 3-D finned tube, the heat transfer coefficient increased with an increase of the H2O volume fraction and HCl volume fraction. In addition, when the H2O volume fraction was 10%, the 3-D finned tube had 87.2%–95.4% higher heat transfer coefficient and 91.3%–97.1% higher heat transfer rate compared with the smooth tube.
Failure Investigation of Secondary Superheater (SSH) Tube Boiler in the Coal Switching Case
Authors: Hermawan Rachmat , Rooscote Didi , Kustiawan Agung Sidang , Nugraha Herry 
Published: February 2023

Abstract
Failure in the boiler tube is one of the major causes of the force outages in a coal-fired power plant. This paper presents a failure investigation on the high-strength alloy ASME SA213 T91 superheater tube of a 600 MW class coal-fired power plant due to coal switching. The research investigated the fuel quality and the materials using the material characterization method and mechanical testing. The potential slagging and fusibility were found based on coal properties. A wide-open rupture with thick and blunt edges is exposed in the tube failure. Several steps for failure investigation were performed. Microstructures of the failed tube show numerous creep voids estimated &lt; 2.5 microns and decomposed into spheroids as evidenced by a decrease in the hardness number 165 HV nearest location of failure. Exposure to high temperatures in the long-term causes the formation of an oxide scale layer on the fireside tube. The thickness of the oxide scale on the inner side tube &gt; 600 microns also accelerates tube failure and shortened creep life is shown by a time rupture value from 16.29 to 0.26 hours with higher operating hoop stress near to failure location. Changes in fuel characteristics are indicated by the value of fusibility of 1190°C and slagging index of 0.473 which can worsen the condition of overheating from the increase in metal temperature. Higher flue gas temperatures due to the coal switching characteristic and higher metal temperatures of tubes above 570°C were identified as the cause of overheating. The finding confirmed that the superheater tube failed by long-term overheating.
Biaxial Stress Inversion in Plate-Like Structures Based on Acoustoelastic Guided Waves
Authors: Zhao Chunyu , Chen Xin , Li Jian , Liu Yang 
Published: February 2023

Abstract
The nondestructive evaluation of stress using guided waves through the acoustoelastic effect has significant importance for the safety of the structure. In this paper, a Semi-Analytical Finite Element (SAFE) method is used to develop the acoustoelastic theory of guided waves propagating in plate-like structures with arbitrarily shaped cross-sections. Based on the anisotropy of the material induced by the axial force, a method for in-situ detection of biaxial stress through multi-angle dispersion change was developed. The inversion algorithm was validated by data of the SAFE method and the Sweeping Frequency Finite Element Modeling (SFFEM) method, respectively. The inversion results of S0 mode under this method are mainly studied, which can achieve accurate stress in-situ detection of the plate-like structure, and the Root Mean Square Error (RMS) can reach below 1%.
Particle Flow and Packing Behavior of Electron Beam Melting Ti-6Al-4V Powder Under Atmospheric and Vacuum Conditions
Authors: Kelley Garrett , Mamidala Ramulu 
Published: February 2023

Abstract
Electron beam melting (EBM) is a powder bed fusion process capable of manufacturing metallic components out of a variety of alloys. The process is unique in that it relies on the generation of a uniform, densely packed powder bed under vacuum conditions at high temperatures. Therefore, understanding the behavior of the powder subjected to the build environment is crucial to developing the process further.
This study presents a method for comparing the flowability, angle of repose, and packing arrangements of non-virgin Ti-6Al-4V powder under atmospheric and vacuum conditions. The two-dimensional particle packing behavior was acquired during the filling of a container constructed from microscope slides and double-sided adhesive. Data on the Newton or “kissing” number was then analyzed using optical microscopy. To facilitate identical measurements within a vacuum environment, a device was designed to initiate flow within a vacuum chamber using a photoresistor switch and “mechanical finger”. The results show that vacuum environments have negligible effect on powder behavior. These results are important in understanding the connections between benchtop measurements and how they correlate to powder performance within the build chamber. While not explicitly tested, the potential effects that temperature has on powder flow performance will also be discussed.
Analytical and Computational Modeling of FRP-Metal Joints Made by Ultrasonic Additive Manufacturing
Authors: Zhao Ningxiner , Guo Hongqi , Headings Leon M. , Dapino Marcelo J. 
Published: February 2023

Abstract
Previous research has developed a process for producing strong fiber reinforced polymers (FRP)-metal joints via ultrasonic additive manufacturing (UAM), and structural tests have been conducted to characterize the mechanical properties of the joints. In this research, an analytical model and a finite element analysis (FEA) model are developed for UAM-produced FRP-metal joints to provide better joint design and application insights. The analytical model applies both the thick-wall cylindrical pressure vessel theory and Tsai-Wu failure criterion to characterize the stress condition in the embedded fibers and the failure mode when tension is applied to the joint. Comparing the analytical model and experimental results of two different sample configurations, the model is able to predict the peak load of the joint with given material properties and joint geometries. Based on the analytical model, an FEA model is built using LS-DYNA to simulate the tensile testing of FRP-metal joint using shell mesh by homogenizing the hybrid portion of the joint. The stress maps obtained from the FEA model for two joint designs show similar distributions when compared to measured digital image correlation (DIC) strain maps, indicating that the failure modes match the experimental results. The FEA simulation results agree well with the experimental result for peak load and displacement at fracture, with an error of less than 5%.
Integration of Minivalves With RNA Amplification Device for Simultaneous Detection of SARS-CoV-2 and Influenza Viruses
Authors: Alipanah Morteza , Manzanas Carlos , A. Lednicky John , Wu Chang-Yu , Fan Z. Hugh 
Published: February 2023

Abstract
We report a point-of-care (POC) device for simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A viruses. The device carries out sample preparation using ball-based valves for sequential delivery of reagents. A microfluidic paper-based analytical device (μPAD) in the detection unit enables RNA isolation and enrichment, followed by reverse transcription loop-mediated isothermal amplification (RT-LAMP) and colorimetric detection. The device integrates all the necessary steps for the sample preparation, including virus lysis, RNA enrichment and purification of two virus samples. The device enabled simultaneous detection of SARS-CoV-2 and Influenza A N1H1 viruses in 50 min., with limit of detection of 2 and 6 genome equivalents (GEs), respectively. The device was also capable of detecting environmental sample of the two viruses.