bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete Shaking-Force, -Moment, and, -Torque Balancing of Multi-Cylinder Engines Without Requiring Harmonic Balancers
Authors: Bagci Cemil 
Published: February 2021

Abstract
Conventional engine balancing process truncates the piston acceleration to form harmonics form for the shaking force; then using dynamically equivalent two-particle mass system for the connecting rod, the shaking force is balanced by arranging the phase angles of the crank throws. During this process, the shaking torque balancing (about the crank shaft axis) is ignored. Shaking force due to truncated portion of piston acceleration is left unbalanced; and that some phase angle arrangements cannot balance the harmonics of the shaking force. This requires force harmonic balancers. Unbalanced inertial forces generate shaking moment about the transverse axis (normal to crankshaft axis) that remains unbalanced. Shaking moment due to force harmonics for some phase angles also remain unbalanced. They require moment harmonic balancers.
This article presents a complete balancing method by which shaking force in each slider-crank loop is completely balanced. This also means that shaking moment is also completely balanced, thus eliminating the need for both force-, and moment-harmonic balancers. Article uses linearly independent mass vector method to retain the total center of mass of each slider-crank loop stationary. Shaking torque (sum of the inertial torques about the axis parallel to the crankshaft axis) causes variation in the output torque generated. This variation may be considered when designing the flywheel. However, the shaking torque is also balanced (or minimized) retaining the total angular momentum of each loop constant by arranging the phase angles of the crank throws. Several multi-cylinder engines are completely balanced for shaking force, shaking moment and shaking torque in the application examples, including balanced designs of connecting rod and throw sides.
Pseudo-Interference Stiffness Estimation in Gear Teeth Contact
Authors: Lee Geunho , Kazarounian Kazem , Koenig Herbert A. 
Published: February 2021

Abstract
One of the important factors in gear dynamic analysis is accurate estimation of the mesh stiffness. To accurately model the mesh stiffness characteristics, the Pseudo-Interference Stiffness Estimation (PISE) method is proposed. PISE draws upon the finite element analysis method. It also analyzes the non-linear, geometric based characteristics of the local contact region. Consequently, PISE is used to model the elastic deformation at the mesh regions and estimate the corresponding stiffnesses in the elastic region.
In this paper, as an example, PISE is applied to the two cylinders’ contact problem. Thus the PISE solution is compared with exact analytical solution which is readily available in literature. Subsequently, PISE is used to model the contact region and estimate the mesh stiffness of a gear system.
Compliant Parallel-Guiding Mechanisms
Authors: Derderian James M. , Howell Larry L. , Murphy Morgan D. , Lyon Scott M. , Pack Spencer D. 
Published: February 2021

Abstract
The rigid-link parallel-guiding (or parallelogram) mechanism is perhaps one of the simplest closed-loop mechanisms to analyze. Compliant parallel-guiding mechanisms, often called plate-spring mechanisms, are in common use in many applications. Advances in compliant mechanism modeling and synthesis have provided an opportunity to apply these mechanisms in an even wider range of uses. Unlike the rigid-link parallel-guiding mechanism which has a simple configuration defined by one kinematic chain, this paper reveals that twenty-eight compliant parallel-guiding mechanism configurations exist. Also, traditional plate spring mechanisms have been designed to function in the linear, small-deflection range and this paper describes a design approach that allows for deflections well into the non-linear range. The purpose of this paper is then threefold: i) identify all configurations of compliant parallel-guiding mechanisms, ii) provide a method for the design and analysis of compliant parallel-guiding mechanisms, and iii) provide experimental data to validate the above purposes. Additionally, the third purpose mentioned is important outside of the context of the parallel-guiding mechanism. The experimental results presented will help to validate the pseudo-rigid-body-model concept.
Analysis of Latching Systems in Deployers of Deployable Structures Using Generalized Yale Lock and Sequential Logic
Authors: Chew M. , Ho M. T. 
Published: February 2021

Abstract
Deployable structures can be erected from a folded configuration using a mechanism known as a deployer. Many latches are present in a deployer. These latches are coordinated in a logical and systematic manner to bring about the deployment of an associated deployable space structure. This article presents an investigation into the systematic analysis of the logical behavior of a latching system for a deployer on the MAST I flight experiment. Three approaches, a modification of the Generalized Yale Lock, Sequential Logic, and a combination of these two approaches — the Sequential Yale Lock, will be applied to the analysis and design of the latching system. A comparison of the approaches provides insight to the applicability of each of the approaches.
Spherical Four-Bar Linkage Mechanism for Continuous Passive Movement Rehabilitation Treatment of the Ankle
Authors: Ham Kealy R. , Erdman Arthur G. , Hong Boyang 
Published: February 2021

Abstract
Continuous passive movement (CPM) is an important process in the post-operative rehabilitation treatment of the knee. The two-dimensional, flexion/extension motion provided by CPM has been shown to have beneficial effects on tendon, cartilage, and ligament health via increased blood flow to the knee and surrounding tissues. Similarly, CPM may be useful in the rehabilitation of the ankle. However, the ball and socket joint of the ankle would benefit more from a three-dimensional spherical motion instead of the traditional two-dimensional, flexion/extension motion.
This study presents a four-bar linkage developed with the use of three dimensional mechanical modeling software. The linkage provides a spherical path of motion for the continuous passive movement of the ankle. This spherical CPM may ultimately be useful in the treatment of congenital musculoskeletal abnormalities, acquired joint disorders, and traumatic injury of the ankle.
A Study on the Grasp Synthesis Using the Line Geometry
Authors: Tsai Ming-June , Chen Fong-Zhi 
Published: February 2021

Abstract
The applications of line geometry to grasp analysis and synthesis is presented in this paper. Since most of the contact wrenches are of zero pitch, they can be described as lines. The geometrical representation of the linearly dependent lines can reduce the complexity of grasp research. The geometrical characteristics of rank 3 dependent line sets are discussed. The geometrical characteristics are then applied to the force closure grasp and grasp synthesis of a four-fingered hand. A new grasp model is derived to illustrate the application of line geometry to simplify grasp transformation.
Construction of a Six-Degrees-of-Freedom Parallel Manipulator With Three Planarly Actuated Links
Authors: Ben-Horin Ronen , Shoham Moshe 
Published: February 2021

Abstract
The construction of a new type of a six-degrees-of-freedom parallel robot is presented in this paper. Coordinated motion of three planar motors, connected to three fixed-length links, produces a six-degrees-of-freedom motion of an output link. Its extremely simple design along with much larger work volume make this high performance-to-simplicity ratio robot very attractive.
Dynamics and Control of an Adaptive Disk Suspension System Under Inertial Loading
Authors: Yang Li-Farn , Tzeng Rueih-Chir , Kuo Chun-Pao 
Published: February 2021

Abstract
A zero-stiffness suspension system featuring a noncircular disk is used as an application in counteracting gravity loads in ground-based structural testing. The dynamic behavior of this mechanism is analyzed in closed form, in which this mechanism is shown to be very sensitive to inertial properties of noncircular disk which can introduce inertial forces to trigger nonlinear dynamic behavior in the system, thereby degrading testing performance under such inertial loading. An adaptive feedforward control law is developed for eliminating these inertial effects upon the suspension system during dynamic testing. Under this control manipulation, the output signals of disk mechanism are regulated and tracked along the desired trajectories so that the error signals can vastly be reduced. Stability of the control system is investigated, and simulated-time histories of test articles under an active band-drive suspension system will also be presented to show the effectiveness of the present approach.
A Proposed Model for Stochastic Vibration Analysis of Gear Transmission Systems
Authors: Wang Y. , Zhang W. 
Published: February 2021

Abstract
A new mathematical model is presented for analyzing the vibration of gear transmission systems with consideration of the influence of the time-variant stiffness, loads, gear transmission errors. The gear transmission system is modeled as a non-linear, time-correlated and stationary stochastic system. The transmission errors of gears are decomposed into harmonic and random components in terms of the different characteristics of their spectrums. The random component is simulated by a second order Markov process. A simulation system for vibration analysis of gear transmission systems is then developed, based on this new model. The input to this system is a Guassian white noise process and harmonic errors, and the output is the rotational vibration acceleration of gears. Some experiments are conducted to verify the proposed model. By comparing the results generated from the simulation system with those from the experiments, the proposed model is found to reach a fairly good accuracy, and thus the model is useful in designing gear transmission systems with the objective to reduce the vibration and noise of the systems in operation.
A Methodology for the Configuration Synthesis of Machining Centers With Automatic Tool Changer
Authors: Yan Hong-Sen , Chen Fu-Chen 
Published: February 2021

Abstract
The purpose of this paper is to present a design methodology for the configuration synthesis of machining centers with automatic tool changer to meet the required topology and motion characteristics. According to the concept of coordinate systems, graph theory, generalization, specialization, and motion synthesis, this design methodology is proposed and computerized, and the machining centers with automatic tool changer up to eight links are synthesized. As the result, for the machining centers with drum type tool magazine, the numbers of configurations of machining centers with 6, 7, and 8 links are 2, 13, and 20, respectively. And, for the machining centers with linear type tool magazine, the numbers of configurations of machining centers with 5, 6, 7, and 8 links are 1, 5, 20, and 60, respectively. Furthermore, this work provides a systematic approach for synthesizing spatial open-type mechanisms with topology and motion requirements.
Late Neoproterozoic–early Paleozoic basin evolution in the Cathaysia Block, South China: Implications of spatio-temporal provenance changes on the paleogeographic reconstructions in supercontinent cycles
Authors: Xue Er-Kun , Wang Wei , Zhou Mei-Fu , Pandit Manoj K. , Huang Si-Fang , Lu Gui-Mei 
Published: February 2021

AbstractThe role of the Cathaysia Block, South China, and its linkage with orogenesis in the Rodinia and Gondwana supercontinents remain unresolved because of uncertainties in its paleoposition in supercontinental reconstructions. The lithostratigraphic, geochronologic, geochemical (including isotopic), and paleocurrent data on late Neoproterozoic to early Paleozoic sub-basins in the Cathaysia Block reveal spatio-temporal, tectono-sedimentary, and provenance diversity that show linkages with previously adjacent terranes and orogens in East Gondwana. An abundance of siliceous and conglomeratic rocks, local unconformities, and pinch-out in certain layers indicate a late Cryogenian proximal deposition, late Ediacaran transgression, and Middle Cambrian uplift. Cryogenian to early Ordovician strata contain predominantly 1000–900 Ma (late Grenvillian age) detrital zircon population, whereas 1300–1050 Ma (early Grenvillian age) zircons are only dominant in strata earlier than late Ediacaran. Besides, 850–700 Ma zircons are the most prominent group in the Middle Cambrian strata along with an occasional increase in the 650–500 Ma (Pan-African age) zircons.The Grenvillian age zircon groups exhibit significant sediment input from the eastern Indian terrane (990–950 Ma) and western Australia (1300–1050 Ma), underlining the fact that the Cathaysia Block was located between these two terranes in the northern part of East Gondwana. The diminishing contribution of early Grenvillian components in the late Ediacaran strata can be linked to the Pinjarra Orogeny (550–520 Ma), which led to uplift that blocked the transport of detritus from Australia. Middle Cambrian provenance variation with high abundance of 850–700 Ma components indicates the presence of intrinsic sediment from the Wuyishan terrane of South China. Given that the Cathaysia Block was a passive continental margin, this change was caused by the uplift of the southeastern Cathaysia Block, which was related to the far-field stress effects of the late phase of the Kuunga Orogeny (530–480 Ma). The decrease in abundance of early Grenvillian and Pan-African zircons in space implies that they were transported into the basins through independent drainage systems. This is consistent with the local and temporal variations in paleocurrent orientations during the Cambrian, further implying diverse and complex drainage systems in the southwestern Cathaysia Block during this period.
Facies interpretation and geochronology of diverse Eocene floras and faunas, northwest Chubut Province, Patagonia, Argentina
Authors: Gosses Justin , Carroll Alan R. , Bruck Benjamin T. , Singer Brad S. , Jicha Brian R. , Aragón Eugenio , Walters Andrew P. , Wilf Peter 
Published: February 2021

Abstract
The Eocene Huitrera Formation of northwestern Patagonia, Argentina, is renowned for its diverse, informative, and outstandingly preserved fossil biotas. In northwest Chubut Province, at the Laguna del Hunco locality, this unit includes one of the most diverse fossil floras known from the Eocene, as well as significant fossil insects and vertebrates. It also includes rich fossil vertebrate faunas at the Laguna Fría and La Barda localities. Previous studies of these important occurrences have provided relatively little sedimentological detail, and radioisotopic age constraints are relatively sparse and in some cases obsolete. Here, we describe five fossiliferous lithofacies deposited in four terrestrial depositional environments: lacustrine basin floor, subaerial pyroclastic plain, vegetated, waterlogged pyroclastic lake margin, and extracaldera incised valley. We also report several new 40Ar/39Ar age determinations. Among these, the uppermost unit of the caldera-forming Ignimbrita Barda Colorada yielded a 40Ar/39Ar age of 52.54 ± 0.17 Ma, ∼6 m.y. younger than previous estimates, which demonstrates that deposition of overlying fossiliferous lacustrine strata (previously constrained to older than 52.22 ± 0.22 Ma) must have begun almost immediately on the subsiding ignimbrite surface. A minimum age for Laguna del Hunco fossils is established by an overlying ignimbrite with an age of 49.19 ± 0.24 Ma, confirming that deposition took place during the early Eocene climatic optimum. The Laguna Fría mammalian fauna is younger, constrained between a valley-filling ignimbrite and a capping basalt with 40Ar/39Ar ages of 49.26 ± 0.30 Ma and 43.50 ± 1.14 Ma, respectively. The latter age is ∼4 m.y. younger than previously reported. These new ages more precisely define the age range of the Laguna Fría and La Barda faunas, allowing greatly improved understanding of their positions with respect to South American mammal evolution, climate change, and geographic isolation.
Latitudinal variability in the Quaternary development of the Eurasian ice sheets—Evidence from the marine domain
Authors: Hjelstuen Berit Oline , Sejrup Hans Petter 
Published: February 2021

Abstract
Here we present the first compilation of sediment volumes, sedimentation rates, and chronology of Quaternary sediment packages along the entire marine margin of the Eurasian ice sheets (EurIS; British–Irish, Kara–Barents Sea–Svalbard, and Fennoscandian). This compilation allows for a subdivision of the EurIS development into three phases (2.6–1.5 Ma, 1.5–0.78 Ma, and 0.78–0 Ma). At the start of the Quaternary, sedimentation rates increased, relative to pre-Quaternary rates, by an order of magnitude. This abruptness in rate change excludes tectonic raising of landmasses as the main factor, but more likely reflects climate change through increased glacial erosion. The sediment distribution data suggest that the Kara–Barents Sea–Svalbard Ice Sheet (KBSIS) already was quite large at the beginning of the Quaternary, and well before 1.5 Ma it extended to the shelf edge and coalesced with the Fennoscandian Ice Sheet (FIS), which prior to 1.5 Ma most likely was located near the coast. Large ice streams and intense glacial erosion characterized the KBSIS in the 1.5–0.78 Ma time period, whereas the FIS at that time extended farther out on the continental shelf. After 0.78 Ma, a north-south change in EurIS development occurred. In the FIS and the British–Irish Ice Sheet (BIIS), large ice streams developed and shelf-edge glaciations occurred nearly 1 m.y. later compared to the KBSIS. The FIS and BIIS also repetitively coalesced in the North Sea. A significant drop in sediment input along the KBSIS marine margin, to the lowest Quaternary level, suggests a less erosive KBSIS.
The Permian Monos Formation: Stratigraphic and detrital zircon evidence for Permian Cordilleran arc development along the southwestern margin of Laurentia (northwestern Sonora, Mexico)
Authors: Dobbs Stephen C. , Riggs Nancy R. , Marsaglia Kathleen M. , González-León Carlos M. , Cecil M. Robinson , Smith M. Elliot 
Published: February 2021

AbstractThe southwestern margin of Laurentia transitioned from a left-lateral transform margin to a convergent margin by middle Permian time, which initiated the development of a subduction zone and subsequent Cordilleran arc along western Laurentia. The displaced Caborca block was translated several hundred kilometers from southern California, USA, to modern Sonora, Mexico, beginning in Pennsylvanian time (ca. 305 Ma). The Monos Formation, a ∼600-m-thick assemblage of mixed bioclastic and volcaniclastic units exposed in northwestern Sonora, provides lithostratigraphic, petrographic, and geochronologic evidence for magmatic arc development associated with subduction by middle Permian time (ca. 275 Ma).The Monos Formation was deposited in a forearc basin adjacent to a magmatic arc forming along the southwestern Laurentian margin. Detrital zircon U-Pb geochronology suggests that Permian volcanic centers were the primary source for the Monos Formation. These grains mixed with far-traveled zircons from both Laurentia and Gondwana. Zircon age spectra in the Monos Formation are dominated by a ca. 274 Ma population that makes up 65% of all analyzed grains. The remaining 35% of grains range from 3.3 Ga to 0.3 Ma, similar to age spectra from Permian strata deposited in the Paleozoic sequences in the western continental interior. An abundance of Paleozoic through early Neoproterozoic ages suggests that marginal Gondwanan sources from Mexico and Central America also supplied material to the basin.The Monos Formation was deposited within tropical to subtropical latitudes, yet faunal assemblages are biosiliceous and heterotrophic. The lack of photozoan assemblages suggests that cold-water coastal upwelling combined with sedimentation from the Cordilleran arc and Laurentian continent promoted conditions more suitable for fauna resilient to biogeochemically stressed environments.We propose that transform faulting and displacement of the Caborca block ceased by middle Permian time and a subduction zone developed along the southwestern margin of Laurentia as early as early Permian time. The Monos basin developed along the leading edge of the continent as a magmatic arc developed, and facies indicate a consistent shoaling trend over the span of deposition.
Long-term outcomes in children with absent pulmonary valve syndrome: it is not just fixing the heart
Authors: Torok Katalin , Brettle Elizabeth , Desai Tarak , Miller Paul , Khan Natasha , Stickey John , Nagakumar Prasad , Seale Anna 
Published: February 2021

ObjectiveAbsent pulmonary valve syndrome (APV) is a rare condition usually associated with tetralogy of Fallot (TOF). Some infants develop respiratory failure from bronchial compression and the long-term neurodevelopmental outcome is unknown. We aimed to investigate the outcomes of APV and the need for long-term ventilation (LTV).Design, patients and settingRetrospective single-centre review of patients diagnosed with APV between 2007 and 2017.Outcome measuresSurvival, neurological disability and postoperative LTV (≥3 months of non-invasive or invasive respiratory support).ResultsThirty patients were identified, 22 (73%) of whom were prenatally diagnosed. Pregnancy was discontinued in one patient, while in utero death occurred in three. One was lost to follow-up. Of the remaining 25 liveborn, 21 had the classic TOF/APV. One baby died immediately after birth, while two patients had palliative care due to severe airway compression and inability to wean ventilation support. Surgical repair was performed in 21 of the 25 (84%) liveborn, with one awaiting surgery. Of those undergoing surgery, two patients died: one during surgery and the other due to severe airway malacia 5 months postsurgery. In the surgical group survival from birth at 1 and 5 years was 89% (95% CI 75% to 100%). Six (30%) patients required LTV postoperatively; all had surgery within the first 6 months of life. Learning and/or other physical difficulties were evident in 63%.ConclusionsMajority of patients with APV are diagnosed antenatally. A third of those operated required LTV and over half had learning and/or other physical difficulties. Prospective studies are needed to identify prenatal factors that predict postnatal outcomes so parents can be counselled appropriately.