bluuebunny/crossref_metadata_2025_split huggingface dataset:
RUVBL proteins are involved in plant gametophyte development
Authors: Dvořák Tomaštíková Eva , Yang Fen , Mlynárová Kristína , Hafidh Said , Schořová Šárka , Kusová Alžbeta , Pernisová Markéta , Přerovská Tereza , Klodová Božena , Honys David , Fajkus Jiří , Pecinka Ales , Schrumpfová Petra Procházková 
Published: February 2023

SUMMARYThe proper development of male and female gametophytes is critical for successful sexual reproduction and requires a carefully regulated series of events orchestrated by a suite of various proteins. RUVBL1 and RUVBL2, plant orthologues of human Pontin and Reptin, respectively, belong to the evolutionarily highly conserved AAA+ family linked to a wide range of cellular processes. Previously, we found that RUVBL1 and RUVBL2A mutations are homozygous lethal in Arabidopsis. Here, we report that RUVBL1 and RUVBL2A play roles in reproductive development. We show that mutant plants produce embryo sacs with an abnormal structure or with various numbers of nuclei. Although pollen grains of heterozygous mutant plants exhibit reduced viability and reduced pollen tube growth in vitro, some of the ruvbl pollen tubes are capable of targeting ovules in vivo. Similarly, some ruvbl ovules retain the ability to attract wild‐type pollen tubes but fail to develop further. The activity of the RUVBL1 and RUVBL2A promoters was observed in the embryo sac, pollen grains, and tapetum cells and, for RUVBL2A, also in developing ovules. In summary, we show that the RUVBL proteins are essential for the proper development of both male and particularly female gametophytes in Arabidopsis.
CT features of rounded atelectasis in chronic inflammatory pleural effusions in cats and dogs
Authors: Tran Danielle T. H. , Donovan Taryn A. , Daverio Heather , Le Roux Alexandre B. 
Published: February 2023

AbstractRounded atelectasis is well described in human medicine as focal lung deformation and collapse secondary to inflammatory pleural effusions and pleuritis. Specific CT features (round to ovoid soft tissue pulmonary attenuations, creation of an acute angle with the adjoining visceral pleura, and the presence of perinodular comet tail signs) support the diagnosis of rounded atelectasis in humans so that further diagnostic workup is not necessary in defining the nodules. In this retrospective case series, we described the CT characteristics of rounded atelectasis in eight cats and three dogs diagnosed with restrictive pleuritis secondary to either a chylothorax or pyothorax. Thirty‐six soft tissue attenuating pulmonary nodular lesions were identified on CT. Comet tail signs, consisting of bundles of bronchi and vessels coalescing into the pulmonary nodules, were associated with 92% of the nodules (33/36), and 92% of the nodules abutted and created an acute angle with the pleura (33/36). Other prevalent features included location in gravity‐dependent regions of the lung lobes (33/36, 92%), blurred hilar margins with sharper pleural margins of the nodules (33/36, 92%), presence of air bronchograms (30/36, 83%), homogeneous contrast‐enhancement (23/36, 64%), and volume loss of the affected lung lobe (22/36, 61%). Pulmonary malignant neoplasms were not found cytologically (6/11 patients) or histologically (5/11 patients). To avoid a misdiagnosis of neoplasia, veterinary radiologists should be aware of the CT features of rounded atelectasis and consider it as a differential for pulmonary nodular lesions in patients with concurrent inflammatory pleural effusion and pleuritis.
Investigation of Conjugate Effects on Forced Convection in Diamond (Diverging–Converging) Microchannels
Authors: Goli Sandeep , Saha Sandip K. , Agrawal Amit 
Published: February 2023

Abstract
A three-dimensional solid–fluid conjugate model is employed to provide physical insights into the effect of wall conduction on fluid convection in a diamond-shaped microchannel. The study covers the effect of divergence-convergence angle, width ratio, thermal conductivity ratio, thickness ratio, and Reynolds number on peripheral heat flux, temperature, and Nusselt number profiles. Isotherms show a multidirectional thermal gradient for low thermal conductivity ratios, whereas only an axial thermal gradient is seen for higher thermal conductivity ratios. Furthermore, the overall axial surface temperature gradients decrease with increasing divergence-convergence angle and decreasing width ratio. The study also shows that the thermal conductivity ratio significantly influences the Nusselt number, while the thickness ratio has only a moderate influence for all geometries. The analysis also reveals that at a particular intermediate thermal conductivity ratio, the Nusselt number becomes maximum. Lastly, a nondimensional wall conduction number is used to characterize conjugate effects in diamond microchannels. The wall conduction effect is inconsequential in diamond microchannels when the nondimensional wall conduction number is less than 0.01. The present study is beneficial from a practical perspective as it helps design the optimum channel geometries subjected to conjugate effects for many heat transfer applications.
Three 2-DOF 1T1R and One 3-DOF 2T1R Full-Hinged Novel Parallel Mechanisms With Zero Coupling Degree and Motion Decoupling: Design and Analysis
Authors: Li Ju , He Hongbo , Wu Guanglei , Li Tao , Shen Huiping 
Published: February 2023

AbstractThis paper presents the design and analysis of a family of full-hinged partially-decoupled novel parallel mechanisms (PMs) featuring one/two translation(s) and one rotation (1T1R/2T1R). First, three 2DOF 1T1R and one 3DOF 2T1R novel spatial PMs are proposed, according to topology design theory of PM based on position and orientation characteristic (POC) equations. The 3DOF 2T1R PM is illustrated to show its topological characteristics, such as POC set, degrees-of-freedom (DOF), and coupling degree (k), which show that the PM does not produce parasitic motion, with the coupling degree k being equal to zero. Second, the kinematic and dynamic performances of the 3DOF 2T1R PM are analyzed, including symbolic forward position solutions based on its topological characteristics, the workspace based on both the forward and inverse position solutions, respectively, the singular configurations based on the inverse position solutions, and the dynamic analysis built by means of the virtual work principle based on the single-open-chain units. Finally, the potential application of the proposed 3DOF 2T1R PM, namely, lifting and transferring lightweight workpieces between two perpendicular conveyor belts on the floor, is introduced.
Skin Cooling of Turbine Airfoils by Single-Wall Effusion—Part II: Computational Fluid Dynamics Validation and Preliminary Design Optimization on a Micro-Turbine Vane
Authors: Lange Yair , Kırmızıgöl S. Fatih , Acarer Sercan , Cukurel Beni 
Published: February 2023

AbstractA reduced-order model (ROM) is developed to capture conjugate aero-thermal physics of effusion cooling in an entire micro-turbine vane/blade. The model considers a single-wall effusion scheme with internal boundary layer flow between the shell and an inner core. Coolant is supplied inside the leading edge and spread to both suction and pressure sides. The compound effect of multiple effusion rows is used to calculate spanwise-averaged cooling effectiveness. Metal temperature is modeled both in streamwise and shell thickness directions. The development of the model and a number of numerical/experimental validation cases are presented in detail in Part I. Part II of the work is geared toward the application of this method to skin cooling of a turbine airfoil by single-wall effusion. The reduced-order model, with all its subroutines functioning together, is validated against a higher fidelity 3D Reynolds-averaged Navier–Stokes (RANS) computational fluid dynamics (CFD) solution. It is shown that the model can predict the main features of the combined internal and effusion cooling in gas-turbine blades at a computational cost which is 105 times lower than RANS (∼1 month with 700M elements and 24 modern Xeon Cores) on a whole turbine vane/blade. Due to this great advantage in speed, a design optimization is then accomplished toward minimizing coolant flow rate while keeping thermal gradients and temperature of the solid within acceptable levels. Implementing this scheme on a typical micro-gas-turbine vane, optimal distributions of the effusion-hole pitch and diameter are found within a given set of constraints. This preliminary design tool potentially enables wider and more efficient usage of effusion cooling in turbine vanes/blades.
Research on Parasitic Power of Cooling Balance of Plant System for Proton Exchange Membrane Fuel Cell
Authors: Chang Guofeng , Xie Chengyu , Cui Xian , Wei Pengnan 
Published: February 2023

AbstractIn high-power systems of proton exchange membrane fuel cells (PEMFC), cooling systems for the balance of plants (BOP) play an extremely important role in maintaining the temperature of the key components of the fuel cell system. To evaluate the effect of the PEMFC BOP cooling system on the fuel cell system efficiency, a Simulink model of the fuel cell system and an AMEsim model of the cooling system for the BOP system are established based on experimental data. A co-simulation is conducted based on the established models to determine the effects of fuel cell stack output power, coolant flowrate, radiator fan speed, and temperature control strategies on the parasitic power consumption and fuel cell system efficiency. The simulation results show that with an increase in the stack output power, coolant flowrate, and radiator fan speed, the parasitic power of the BOP cooling system increases and the system efficiency of PEMFC decreases. With an increase in the opening temperature of the radiator fan, the parasitic power of the BOP cooling system decreases and the system efficiency of the PEMFC increases. Compared with the rule-based control strategy, the radiator fan speed control strategy based on the PID controller achieves lower parasitic power. The research presented in this paper is helpful for further development of efficient fuel cell vehicle thermal management system.
Using Freeze-Casting Method to Create Lamellar Copper Structures – An Experimental Study of the Freezing Behavior of Cupric Oxide Colloidal Suspensions
Authors: Kasprzak Christopher , Hoffman Christina , Chen Ruey-Hung , Zhu Liang , Ma Ronghui 
Published: February 2023

Abstract
This study investigates the directional solidification behavior and the effects of initial freezing temperature on the formation of porous structure. The aqueous suspension with 10 vol.% cupric oxide (CuO) particles is prepared by mixing CuO particles, polyvinyl alcohol, and polyvinylpyrrolidone in deionized water. Additionally, potassium hydroxide is used to adjust the pH values between 8–10. Based on the measurement of the suspension viscosity, the optimal amount of the dispersant and the range of pH values that enable a well dispersed and stable suspension is identified. The freezing curves of the suspensions are measured to obtain the freezing point of the suspension as well as the effect of the potassium hydroxide on the freezing behavior. The suspensions then undergo directional freezing under various initial freezing temperatures. After sublimation under a near vacuum pressure, the green samples are infiltrated with epoxy to facilitate visualization and characterization of the pore morphology and orientation using an optical microscope. We believe that the obtained relationship between the freezing conditions, and the structural specifics of freeze-cast porous CuO lays the groundwork for freeze-cast porous copper with desirable pore morphology and structures for thermal management and energy storage applications.
Grid-Video Measurement Method for A-UGV’s Small Obstacle Avoidance Performance
Authors: Yoon Soocheol , Bostelman Roger , Virts Ann 
Published: February 2023

Abstract
With the advancement of factory logistics into the autonomous era comes the need to validate the safety and performance characteristics of Autonomous-Unmanned Ground Vehicles (A-UGVs) working in these application spaces ASTM Committee F45 has been developing standards for A-UGV performance measurement in various domains. The object detection and obstacle avoidance performance of A-UGVs in factories needs to be managed carefully as the action may cause severe damages, particularly when obstacles are either not detected or erroneously detected. In this paper, the grid-video measurement method is proposed to measure the small (e.g., short and/or thin) obstacle avoidance performance of A-UGVs. First, this paper describes the need for measuring the A-UGV performance through examples of small obstacles and the required A-UGV capability to avoid them. Next, the grid-video measurement method is introduced as a low cost, standard method to measure the small obstacle avoidance performance of A-UGVs. An experiment using blocks demonstrates how the grid-video measurement method can be used effectively to measure the A-UGV obstacle avoidance performance, and it shows that the performance changes upon A-UGV specification, obstacle sizing, and environmental conditions quantitively. The method and experimental results proposed in this paper will be used to support ASTM F45 standard development.
Micro-Crack Formation in Laser Structuring of Titanium Alloys for Orthopedic Applications
Authors: Yang Can , Fu Yunxiang , Liu Xiao-Hua , Yin Xiao-Hong , Liu Kewei , Li Chun-Bo , Zheng Xiuhong , Yang Bao-Hua 
Published: February 2023

Abstract
Titanium alloys have been widely employed as essential raw materials for manufacturing implants in orthopedics due to their excellent biocompatibility, corrosion resistance, and mechanical properties similar to human bones. In order to form effective bonding between the titanium alloy implant and the human bone at an appropriate time, micro-structures are required to create on titanium alloy surfaces through surface modification, so that the bone cells can propagate and grow. Laser-induced micro/nano hierarchical structures on titanium alloy implants are capable of improving the adhesion, arrangement and proliferation of osteoblasts. However, significant micro-crack appears on the metal surfaces after the nanosecond laser treatment, which will do harm to mechanical and corrosion resistance performances of the implants and may even in turn damage patients’ health. This work aims at investigating the formation mechanism and influencing factors of micro-cracks to achieve laser-structured titanium alloy implants with reduced or even no micro-crack for orthopedic applications. Laser ablation experiments were conducted on titanium alloy surfaces to produce micro-grooves/protrusions. Specifically, three key laser process parameters such as the laser scanning speed (v), laser frequency (f), and scan repetition (n) were considered in terms of their influences on the crack morphology. The smaller the laser scanning speed, the large the micro-crack number and the more chaotic of their distribution. The speed of nanosecond laser processing should be increased to reduce the generation of micro-cracks. It can be inferred that micro-cracks on laser-structured titanium alloy surfaces are mainly ascribe to the generated thermal stress during laser processing.
On the Observability of Quantum Dynamical Systems
Authors: Griffith Tristan D. , Gehlot Vinod P. , Balas Mark J. 
Published: February 2023

Abstract
Quantum statistical mechanics offers an increasingly relevant theory for a wide variety of probabilistic systems including thermodynamics, particle dynamics, and robotics. Quantum dynamical systems can be described by linear time invariant systems and so there is a need to build out traditional control theory for quantum statistical mechanics. The probability information in a quantum dynamical system evolves according to the quantum master equation, whose state is a matrix instead of a column vector. Accordingly, the traditional notion of a full rank observability matrix does not apply. In this work, we develop a proof of observability for quantum dynamical systems including a rank test and algorithmic considerations. A qubit example is provided for situations where the dynamical system is both observable and unobservable.
Investigating the Effect of Uniaxial Stress on Guided Wave Propagation in Plates by Wave Finite Element Method
Authors: Zhang Xu , Liu Gang , Chen Lei 
Published: February 2023

Abstract
As an important part of long-range nondestructive testing and structural health monitoring technology, ultrasonic guided wave technology has been used in a wide range of applications in aerospace, petrochemical, transportation, and other fields. This paper extends the previously developed wave finite element method by introducing the prestressing effect in Murnaghan hyperelastic materials and solving the dispersion curves of prestressed waveguide structures. Furthermore, this paper proposes a mode-tracking algorithm based on image sequential alignment that can achieve the multi-mode classification of guided wave dispersion curves and compare the changes in propagation characteristics of different guided wave modes. The results reveal that the change in guided wave phase velocity produced by prestressing is related to the applied stress, frequency-thickness product, and propagation direction and that the susceptibility of different guided wave modes to prestress varies. Finally, the model approach is validated by comparing its predictions to theoretical results from the literature, which match remarkably well. This study is an important guideline for the preferential selection of environmentally insensitive guided wave modes and excitation frequencies, correction of detection signals, and accurate assessment of engineering structure damage information in ultrasonic guided wave technology engineering applications.
Open-Source Virtual Labs for Undergraduate Mechanical Vibrations and Control Theory Courses
Authors: Contreras-Esquen Andrea , Utschig Tristan , Tekes Ayse 
Published: February 2023

Abstract
The vast majority of undergraduate engineering students struggle to acquire a deep understanding of complex topics presented in mechanical vibrations and control theory courses due to their highly mathematical nature, limited resources on the use of commercially available turn-key laboratory equipment, and lack of innovative teaching tools to improve student understanding. In this study, we developed open-source standalone virtual laboratory exercises for vibrations and control theory courses using Matlab Simscape. The virtual labs enable students to change the system parameters, develop a feel of the material, and record and observe the system response through mechanics explorer.
Assessment of Cooling Technologies for Solar Photovoltaic Panels Accounting for Local Solar Irradiance and Ambient Temperature Conditions
Authors: Lucas Aguilar Marcelo , Celis César 
Published: February 2023

Abstract
The growing energy demand and climate change emphasize the need to continuously use environmentally friendly energy sources. Consequently, renewable energy sources such as solar energy, which relies on the use of photovoltaic modules, have become popular in recent years. Photovoltaic (PV) modules convert the incident solar irradiance to electric energy. In such devices, by reducing the operating temperature, the associated solar energy conversion efficiency can be increased, and their lifetime extended. Accordingly, to compare their impact on the performance of PV modules, three different cooling methods, all of them coupled to a thermoelectric (TE) generator, (i) natural cooling, (ii) forced air cooling, and (iii) water cooling, are assessed. To evaluate the referred cooling methods, a computational model describing the behavior of the studied cooling methods is initially developed. Then, a PV model accurately predicting the behavior of commercial PV modules is developed and coupled to the cooling methods one. Finally, accounting for local ambient conditions and system operation over the course of one year, several simulations of PV modules with and without cooling systems are carried out using the developed tool. The main results indicate that some cooling techniques are adequate for some months of the year only, whereas the others do so for the remaining months. Indeed, PV module temperature reductions of up 7.7% and system efficiencies of up to 17.2% are observed. One of the particularities of this work relates to the use of local ambient conditions and system operation over a whole operating year.
An Evolutionary Aeroelastic Design Approach for Spars and Ribs of Flying Wing Aircraft
Authors: Moshtaghzadeh Mojtaba , Rangel Natalia , Bejan Adrian , Mardanpour Pezhman 
Published: February 2023

Abstract
The purpose of this paper is to examine how rib configurations and spar configurations influence flying wing stability. Flying wing aircraft exhibit enhanced flutter characteristics when stresses flow smoothly through the wing. We prevent stress strangulation through spar cross-sections by changing the configuration in the plunge direction. We employ and develop computer programs Gmsh, Variational Asymptotic Beam Sectional Analysis, MATLAB scripts, and Nonlinear Aeroelastic Trim and Stability of High Altitude Long Endurance Aircraft. The configurations are designed by considering the same material, mass, and flight conditions. The results indicate that the design with the smoother stress distribution through the wing has a higher flutter speed. It is shown that the σ11 and Von-Misses stress distributions have an important effect on the stability of a flying wing aircraft.
CFD Modeling of Interstitial Fluid Flow in Subcutaneous Adipose Tissue
Authors: Mokhtar Wael , Lubbers Ryan 
Published: February 2023

Abstract
Adipose tissue is a very important biologic component to nutrient storage and transport. The tissue and flow mechanics of the fluid within the extracellular space is not currently well understood, and difficult to study by experimentation, but could be studied through the development of a mathematical model of the anatomical domain. The study therefore was completed in order to develop a computational fluid dynamics (CFD) model to simulate the interstitial fluid flow in adipose tissue. Various characteristics of the tissue had to be defined by research and experimentation in order to create the model including, but not limited to, the domain size, tissue characteristics, capillarization within the tissue, and oncotic pressure distribution that drives the interstitial flow. The CFD model developed to simulate the interstitial flow within adipose tissue yielded a maximum fluid velocity of 1.85 μm/s, which was found to be within the range of published observed interstitial fluid flow velocities. Also, the model showed that capillarization of the tissue has a large effect the interstitial fluid flow mechanics and pattern in the extracellular space of the adipose tissue. This CFD model development could be used to further adipose tissue understanding as well as drug delivery kinetics in the region.