bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Impeller Sinusoidal Tubercle Trailing-Edge on Pressure Pulsation in a Centrifugal Pump at Nominal Flow Rate
Authors: Lin Yanpi , Li Xiaojun , Li Bowen , Jia Xiaoqi , Zhu Zuchao 
Published: March 2021

Abstract
The high-speed rotation of impellers leads to strong rotor–stator interaction, which mainly causes the pressure pulsation of centrifugal pumps. An impeller with a bionic sinusoidal tubercle trailing edge (STTE) can reduce the intensity of the rotor–stator interaction and thus reduce the pressure pulsation of the centrifugal pump. In this study, three profiles of STTE were designed based on the pectoral fin structure of humpback whales of which the influence on the pressure pulsation of centrifugal pumps was studied via experiment and numerical simulation. Results show that a reasonable design of STTE can effectively eliminate the high-frequency pressure pulsation in the rotor–stator interaction region of the centrifugal pump. The use of STTE2 and STTE3 profiles affect the amplitude reduction of pressure pulsation at the blade passing frequency (fBPF). Compared with the impeller without the STTE profile, the amplitudes of pressure pulsation with STTE2 and STTE3 profiles are decreased by 47.10% and 44.20% at the pump discharge, while the decrease, at the volute throat is 30.36% and 25.97%, respectively. Detailed flow structures inside the pump show that the STTE profile can inhibit the vortex generation at the blade trailing edge, and the local high-intensity pressure pulsation can be reasonably avoided. This study helps improve the pressure pulsation characteristic of centrifugal pumps and their operation stability.
Finite Element Implementation of Biphasic-Fluid Structure Interactions in febio
Authors: Shim Jay J. , Maas Steve A. , Weiss Jeffrey A. , Ateshian Gerard A. 
Published: March 2021

Abstract
In biomechanics, solid–fluid mixtures have commonly been used to model the response of hydrated biological tissues. In cartilage mechanics, this type of mixture, where the fluid and solid constituents are both assumed to be intrinsically incompressible, is often called a biphasic material. Various physiological processes involve the interaction of a viscous fluid with a porous-hydrated tissue, as encountered in synovial joint lubrication, cardiovascular mechanics, and respiratory mechanics. The objective of this study was to implement a finite element solver in the open-source software febio that models dynamic interactions between a viscous fluid and a biphasic domain, accommodating finite deformations of both domains as well as fluid exchanges between them. For compatibility with our recent implementation of solvers for computational fluid dynamics (CFD) and fluid–structure interactions (FSI), where the fluid is slightly compressible, this study employs a novel hybrid biphasic formulation where the porous skeleton is intrinsically incompressible but the fluid is also slightly compressible. The resulting biphasic-FSI (BFSI) implementation is verified against published analytical and numerical benchmark problems, as well as novel analytical solutions derived for the purposes of this study. An illustration of this BFSI solver is presented for two-dimensional (2D) airflow through a simulated face mask under five cycles of breathing, showing that masks significantly reduce air dispersion compared to the no-mask control analysis. In addition, we model three-dimensional (3D) blood flow in a bifurcated carotid artery assuming porous arterial walls and verify that mass is conserved across all fluid–permeable boundaries. The successful formulation and implementation of this BFSI solver offers enhanced multiphysics modeling capabilities that are accessible via an open-source software platform.
Influence of Hydroxyproline on Mechanical Behavior of Collagen Mimetic Proteins Under Fraying Deformation—Molecular Dynamics Investigations
Authors: Rawal Atul , Rhinehardt Kristen L. , Mohan Ram V. , Pendse Max 
Published: March 2021

Abstract
Molecular dynamics modeling is used to simulate, model, and analyze mechanical deformation behavior and predictive properties of three different synthetic collagen proteins obtained from RSC-PDB, 1BKV, 3A08, and 2CUO, with varying concentrations of hydroxyproline (HYP). Hydroxyproline is credited with providing structural support for the collagen protein molecules. Hydroxyproline's influence on these three synthetic collagen proteins' mechanical deformation behavior and predictive properties is investigated in this paper. A detailed study and inference of the protein's mechanical characteristics associated with HYP content are investigated through fraying deformation behavior. A calculated Gibbs free energy value (ΔG) of each polypeptide α chain that corresponds with a complete unfolding of a single polypeptide α-chain from a triple-helical protein is obtained with umbrella sampling. The force needed for complete separation of the polypeptide α-chain from the triple-helical protein is analyzed for proteins to understand the influence of HYP concentration and is discussed in this paper. Along with a difference in ΔG, different unfolding pathways for the molecule and individual chains are observed. The correlation between the fraying deformation mechanical characteristics and the collagen proteins' hydroxyproline content is provided in this study via the three collagen proteins' resulting binding energies.
A Proof-of-Principle Study of the Design and Optimization of a Novel Fluid-Driven Automated Retracting Needle System
Authors: Geelhoed W. J. , Boonekamp M. , van de Stadt H. , Badulescu S. , Lalai R. A. , Groeneweg K. E. , Koning M. , Florijn B. , Horeman T. , Rotmans J. I. 
Published: March 2021

Abstract
The cannulation of blood vessels is one of the most basic and essential interventions in medical practice. A common adverse event of this procedure is miscannulation with infiltration of the second part of the vessel wall, often resulting in a perivascular hematoma. In hemodialysis patients, surgically created arteriovenous conduits are cannulated 3–4 times per week to provide sufficient blood supply to the hemodialysis machine. However, the high blood flow and pressure in these vascular access sites increase the risk of complications upon miscannulation. A novel needle system that allows for rapid automatic retraction of the needle in response to contact with blood after positioning the cannula in the blood vessel was developed to reduce the risk of miscannulation. The device can easily be incorporated into existing needle designs. The mechanical functionality of the device was validated by testing prototypes in an ex vivo system. Optimization of the needle system was performed to enhance response time and piston shape. A final prototype design was manufactured and validated. The optimal membrane composition and piston shape were determined, which resulted in a needle response time of 40 ms upon contact with fluid at a pressure of 100 mmHg (arterial pressure). Here, we have successfully designed, mechanically validated, and tested a novel automated rapid needle retraction system that allows incorporation into existing needle systems. This device could notably decrease the difficulty of vessel cannulation and the prevalence of hematoma formation.
Intermediate Geometric and Interfeature Relationships for Automatic Group Technology Part Coding
Authors: Srikantappa A. B. , Crawford R. H. 
Published: March 2021

Abstract
Group Technology (GT) is a manufacturing philosophy in which similar parts are grouped together to take advantage of their similarities. GT is implemented with a representation that summarizes the important design and manufacturing features of a part in terms of an alphanumeric code. Automated GT coding relies on a complete geometric description of the part, along with a description of the high level manufacturing features such as slots, holes and pockets, and the spatial relationships between these features.
A strategy for the representation and manipulation of interacting and interfeature relationships has been developed. This representation includes a formalism, consisting a set of structural and geometric primitives, along with a methodology for modeling features in the context of interacting and interfeature relationships. This is referred to as the intermediate geometry representation. The information represented includes interactions between features and geometric relationships among features. This paper reports on research to perform automatic GT coding that utilizes the geometric model of the part, the feature model of the part, and the intermediate geometry representation of the part. The interacting and interfeature relationships are shown to significantly facilitate the decision-making processes involved in automated GT coding.
A Simplified Approach for Force and Power-Flow Analysis of Compound Epicyclic Spur-Gear Trains
Authors: Saggere L. , Olson D. G. 
Published: March 2021

Abstract
After conceptual design and dimensional synthesis of a compound epicyclic gear train (EGT), its performance evaluation involves kinematic analysis, force analysis, torque analysis, and power-flow analysis. In recent years, graph theory has proven to be a powerful symbolic representation for design of mechanisms. Application of graph theory for the topological representation and kinematic analysis of EGTs is quite well established. However, graph theory based methods for power-flow and force analysis lack certain features, making them unsuitable or difficult to implement in a general purpose program for automatic design of EGTs. The traditional approach has been to perform force and torque analysis first, and then use the results to perform power-flow analysis. This paper presents a novel, systematic approach in which power-flow analysis is performed first, and then the results are used to determine the inter-link forces in epicyclic spur-gear trains. This method is based only on the graph of the gear-train and the angular velocities of the elements, and hence, is more suitable for automatic computation, simpler to implement in a program, and also avoids requiring the formulation of tedious torque equilibrium equations. A numerical example is presented to illustrate the simplicity and generality of the method.
On the Direct Kinematics of a Class of Spherical Three-Degree-of Freedom Parallel Manipulators
Authors: Gosselin Clément M. , Sefrioui Jaouad , Richard Marc J. 
Published: March 2021

Abstract
This paper presents a polynomial solution to the direct kinematic problem of a class of spherical three-degree-of-freedom parallel manipulators. This class is defined as the set of manipulators for which the axes of the three revolute joints attached to the gripper link are coplanar and symmetrically arranged. It is shown that, for these manipulators, the direct kinematic problem admits a maximum of 8 real solutions. A polynomial of degree 8 is obtained here to support this result and cases for which all the roots of the polynomial lead to real configurations are presented. Finally, the spherical parallel manipulator with collinear actuators, which received some attention in the literature, is also treated and is shown to lead to a minimal polynomial of the same degree. Examples of the application of the method to manipulators of each category are given and solved.
Kinematic Structure Analysis and Classification of Single-Loop Spatial Linkage Mechanisms
Authors: Zhou Y. B. , Fenton R. G. 
Published: March 2021

Abstract
This paper covers the following areas: all practical and typical kinematic input pairs used in a single-loop spatial linkage mechanism (SSLM) are classified using a new symbolic system; four basic groups of SSLMs are defined; and a new kinematic structure classification criterion is proposed, which provides a method to determine the maximum finite number of closures for the mechanism and the maximum order of the input-output displacement equation, free of extraneous roots, describing the kinematics of the SSLMs.
Parametric Deflection Approximations for End-Loaded, Large-Deflection Beams in Compliant Mechanisms
Authors: Howell Larry L. , Midha Ashok 
Published: March 2021

Abstract
Geometric nonlinearities often complicate the analysis of systems containing large-deflection members. The time and resources required to develop closed-form or numerical solutions nave inspired the development of a simple method of approximating the deflection path of end-loaded, large-deflection cantilever beams. The path coordinates are parameterized in a single parameter, called the pseudo-rigid-body angle. The approximations are accurate to within 0.5% of the closed-form elliptic integral solutions. A physical model is associated with the method, and may be used to simplify complex problems. The method proves to be particularly useful in the analysis and design of compliant mechanisms.
Issues on Teaching Kinematics and Mechanism Design
Authors: Erdman Arthur G. , Corrigan Thomas R. 
Published: March 2021

Abstract
The issues, problems and possible solutions involved in teaching a modern course on mechanisms and kinematics are addressed from the perspective of a professor and a student. A historical examination shows the value of modern (computer) solution of classical dilemmas. The structure of an introductory course is then presented, with comments on its educational attributes. The solution of several design problems with LINCAGES©, a computer software package, demonstrates the prowess of the modem student/computer liaison.
Synthesis of Wrapping Cams
Authors: Tidwell Paul H. , Bandukwala Naveed , Dhande Sanjay G. , Reinholtz Charles F. , Webb Greg 
Published: March 2021

Abstract
This paper describes a technique for synthesizing a force generating mechanism composed of a cam wrapped by a belt or chain. Such mechanisms will hereafter be referred to as “wrapping cams.” Synthesis methods for two cases of this mechanism are presented. In the simplest case, the cam is wrapped by a belt or chain under constant tensile force, producing a non-linear torque at the cam. In the second case, the cam is under constant torque, producing a non-linear belt or chain force. While wrapping cams are far less common than cams that generate a specified follower displacement function, applications exist in counter-balancing mechanisms, exercise equipment, and process machines.
Dynamic Analysis of a Spherical Four Bar Mechanism
Authors: Dooley J. R. , McCarthy J. M. 
Published: March 2021

Abstract
Spherical mechanisms are designed so that the points in each link are constrained to move on concentric spheres This paper develops the equations of motion for spherical four bar mechanisms. While the kinematics of these linkages have been extensively studied, the dynamics equations do not seem to have been previously derived. As design techniques for these mechanisms become more efficient, the equations of motion are required to evaluate their performance.
The complete dynamics equations of a four-bar spherical mechanism are derived using the input and output joint angles and the Euler parameters of the coupler as generalized coordinates. These coordinates provide a convenient representation of the constraint equations associated with the closed chain. An example analysis is provided.
Complete Balancing of Linkages Using Complete Dynamical Equivalents of Floating Links: CDEL Method
Authors: Bagci Cemil 
Published: March 2021

Abstract
Partially dynamically equivalent link concept has been used for partial shaking force balancing of the slider-crank mechanisms of engines for a long time. The article offers methods of forming complete dynamically equivalent link (CDEL) for floating binary, ternary, and quaternary links by which a mechanism can be completely balanced eliminating shaking force and shaking moment. Developments and applications are simple. Four-bar and slider-crank mechanisms, Walt’s and Stephenson’s type six-bar mechanisms and some eight-bar mechanisms are completely balanced to illustrate different forms of CDEL in different mechanisms. CDEL uses auxiliary masses and mass moments of inertia on a floating link. The use of the auxiliary masses is illustrated in numerical examples. A Watt’s type body guiding six-bar mechanism interacting with a robot is completely balanced in an application example.
Dynamic Control of Multiple Coordinated Robot Manipulators With Optimal Load Distribution
Authors: Li Chang-Jin , Sankar T. S. 
Published: March 2021

Abstract
The optimal load distribution in multiple robot arm systems, based on minimization of the energy consumption in each collaborating arm, is studied first. Then, for two classes of motion, that is, for trajectory tracking in the joint coordinates and in the object Cartesian coordinates, the corresponding controllers based on the optimal load distribution are developed. Using the joint forces or torques according to the developed controllers can make the actual motion trajectory to asymptotically track the desired trajectory.
Modular Robot Connection Design
Authors: Ambrose Robert O. , Tesar Delbert 
Published: March 2021

Abstract
The ability to reconfigure automation equipment will reduce the manufacturing costs of obsolesence, training and maintenance while allowing for a faster response to changes in the product line. A modular philosophy will give the user these advantages, but only if based on a common connection standard.
A mechanical connection was selected for the UT Modular Robotics Testbed and used in the designs of four robot joint modules and nine robot link modules. The standard was also used for assecories, such as the testand, loading fixtures and endeffectors.
Three years of experiments with this connection standard are reviewed, and used as the basis for new connection designs. Experiments using multiple modules assembled as dextrous robots, as well as experiments focusing on the connection itself, will be described.
Goals for future connection standards include designs with upward compatibility, combinations of both mechanical and electrical fittings, and robot triendly constraints that allow for automated or remote assembly of modular robots.
A Versatile 3-D Tactile Array Gripper Using a Digitally Encoded Sensor
Authors: Friedman Glenn M. , Derby Stephen J. 
Published: March 2021

Abstract
A shape-compliant gripper is proposed that incorporates a matrix array of actuating probes into the fingers. This allows the robot to grasp one of many objects of different surface shapes having arbitrary location and orientation within the grasping envelope. The probes produce a range image by measuring distances between the object’s surface and the sensor plane. The range data is made available to a computer for addressing the problem of identification and localization for flexible assembly, bin sorting, inspection, or other applications.
Late Pleistocene rates of rock uplift and faulting at the boundary between the southern Coast Ranges and the western Transverse Ranges in California from reconstruction and luminescence dating of the Orcutt Formation
Authors: McGregor Ian S. , Onderdonk Nathan W. 
Published: March 2021

AbstractThe western Transverse Ranges and southern Coast Ranges of California are lithologically similar but have very different styles and rates of Quaternary deformation. The western Transverse Ranges are deformed by west-trending folds and reverse faults with fast rates of Quaternary fault slip (1–11 mm/yr) and uplift (1–7 mm/yr). The southern Coast Ranges, however, are primarily deformed by northwest-trending folds and right-lateral strike-slip faults with much slower slip rates (3 mm/yr or less) and uplift rates (&lt;1 mm/yr). Faults and folds at the boundary between these two structural domains exhibit geometric and kinematic characteristics of both domains, but little is known about the rate of Quaternary deformation along the boundary.We used a late Pleistocene sedimentary deposit, the Orcutt Formation, as a marker to characterize deformation within the boundary zone over the past 120 k.y. The Orcutt Formation is a fluvial deposit in the Santa Maria Basin that formed during regional planation by a broad fluvial system that graded into a shoreline platform at the coast. We used post-infrared–infrared-stimulated luminescence (pIR-IRSL) dating to determine that the Orcutt Formation was deposited between 119 ± 8 and 85 ± 6 ka, coincident with oxygen isotope stages 5e-a paleo–sea-level highstands and regional depositional events. The deformed Orcutt basal surface closely follows the present-day topography of the Santa Maria Basin and is folded by northwest-trending anticlines that are a combination of fault-propagation and fault-bend-folding controlled by deeper thrust faults. Reconstructions of the Orcutt basal surface and forward modeling of balanced cross sections across the study area allowed us to measure rock uplift rates and fault slip rates. Rock uplift rates at the crests of two major anticlinoria are 0.9–4.9 mm/yr, and the dip-slip rate along the blind fault system that underlies these folds is 5.6–6.7 mm/yr. These rates are similar to those reported from the Ventura area to the southeast and indicate that the relatively high rates of deformation in the western Transverse Ranges are also present along the northern boundary zone. The deformation style and rates are consistent with models that attribute shortening across the Santa Maria Basin to accommodation of clockwise rotation of the western Transverse Ranges and suggest that rotation has continued into late Quaternary time.
Short term associations of ambient nitrogen dioxide with daily total, cardiovascular, and respiratory mortality: multilocation analysis in 398 cities
Authors: Meng Xia , Liu Cong , Chen Renjie , Sera Francesco , Vicedo-Cabrera Ana Maria , Milojevic Ai , Guo Yuming , Tong Shilu , Coelho Micheline de Sousa Zanotti Staglior , Saldiva Paulo Hilario Nascimento , Lavigne Eric , Correa Patricia Matus , Ortega Nicolas Valdes , Osorio Samuel , Garcia  , Kyselý Jan , Urban Aleš , Orru Hans , Maasikmets Marek , Jaakkola Jouni J K , Ryti Niilo , Huber Veronika , Schneider Alexandra , Katsouyanni Klea , Analitis Antonis , Hashizume Masahiro , Honda Yasushi , Ng Chris Fook Sheng , Nunes Baltazar , Teixeira João Paulo , Holobaca Iulian Horia , Fratianni Simona , Kim Ho , Tobias Aurelio , Íñiguez Carmen , Forsberg Bertil , Åström Christofer , Ragettli Martina S , Guo Yue-Liang Leon , Pan Shih-Chun , Li Shanshan , Bell Michelle L , Zanobetti Antonella , Schwartz Joel , Wu Tangchun , Gasparrini Antonio , Kan Haidong 
Published: March 2021

Abstract

Objective

To evaluate the short term associations between nitrogen dioxide (NO
2
) and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol.

Design
Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis.

Setting
398 cities in 22 low to high income countries/regions.

Main outcome measures
Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018.

Results

On average, a 10 μg/m
3
increase in NO
2
concentration on lag 1 day (previous day) was associated with 0.46% (95% confidence interval 0.36% to 0.57%), 0.37% (0.22% to 0.51%), and 0.47% (0.21% to 0.72%) increases in total, cardiovascular, and respiratory mortality, respectively. These associations remained robust after adjusting for co-pollutants (particulate matter with aerodynamic diameter ≤10 μm or ≤2.5 μm (PM
10
and PM
2.5
, respectively), ozone, sulfur dioxide, and carbon monoxide). The pooled concentration-response curves for all three causes were almost linear without discernible thresholds. The proportion of deaths attributable to NO
2
concentration above the counterfactual zero level was 1.23% (95% confidence interval 0.96% to 1.51%) across the 398 cities.

Conclusions

This multilocation study provides key evidence on the independent and linear associations between short term exposure to NO
2
and increased risk of total, cardiovascular, and respiratory mortality, suggesting that health benefits would be achieved by tightening the guidelines and regulatory limits of NO
2
.