On the Oberwolfach Problem with Two Similar Length Cycles

2001 ◽  
Vol 17 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Darryn E. Bryant
Keyword(s):  
Similar Length ◽  
Oberwolfach Problem

scholarly journals Amalgamation of diverse hydrodynamic effects with novel triple-sided membrane valves for developing a microfluidic device for filterless and continuous water purification

RSC Advances ◽  
2021 ◽  
Vol 11 (46) ◽  
pp. 28723-28734
Author(s):  
Amit Prabhakar ◽  
Ankur Jaiswar ◽  
Neha Mishra ◽  
Praveen Kumar ◽  
Amar Dhwaj ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Water Purification ◽  
Length Scale ◽  
Similar Length ◽  
Hydrodynamic Effects

A microfluidic device displaying multiple hydrodynamic effects was designed to separate suspended impurities (i.e. bacteria and similar length scale particles present in water in the suspension form) from water.

scholarly journals The generalised Oberwolfach problem

2022 ◽  
Vol 152 ◽  
pp. 281-318
Author(s):  
Peter Keevash ◽  
Katherine Staden
Keyword(s):  
Oberwolfach Problem

Effect of Patella Alta on the Native Anatomometricity of the Medial Patellofemoral Complex: A Cadaveric Study

2020 ◽  
Vol 48 (6) ◽  
pp. 1398-1405
Author(s):  
Adam B. Yanke ◽  
Hailey P. Huddleston ◽  
Kevin Campbell ◽  
Michael L. Redondo ◽  
Alejandro Espinoza ◽  
...  
Keyword(s):  
Attachment Site ◽  
Quadriceps Tendon ◽  
Length Change ◽  
Patellar Height ◽  
Extensor Mechanism ◽  
Patella Alta ◽  
Similar Length ◽  
Custom Made ◽  
Length Changes ◽  
Medial Patellofemoral Complex

Background: Patella alta has been identified as an important risk factor for lateral patellar instability and medial patellofemoral complex (MPFC) reconstruction failure. Purpose: To evaluate the length changes of the MPFC at multiple possible reconstruction locations along the extensor mechanism in varying degrees of patella alta throughout knee motion. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knees were used in this study. The MPFC was identified and dissected with the patellar tendon and quadriceps tendon. A custom-made jig was utilized to evaluate lengths from 0° to 90° of flexion with physiological quadriceps loading. Length was measured with a 3-dimensional robotic arm at 4 possible reconstruction locations along the extensor mechanism: the midpoint patella (MP), the MPFC osseous center (FC), the superior medial pole of the patella (SM) at the level of the quadriceps insertion, and 1 cm proximal to the SM point along the quadriceps tendon (QT). These measurements were repeated at 0°, 20°, 40°, 60° and 90° of flexion. Degrees of increasing severity of patella alta at Caton-Deschamps index (CDI) ratios of 1.0, 1.2, 1.4, and 1.6 were then investigated. Results: Patella alta and MPFC attachment site location significantly affected changes in MPFC length from 0° to 90° of flexion ( P< .0005). Length changes at attachment MP showed no difference when CDI 1.0 was compared with all patella alta values (CDI 1.2, 1.4, 1.6; P > .05). Similarly, FC showed no difference in length change from 0° to 90° until CDI 1.6, in contrast to proximal attachments (SM, QT), which demonstrated significant changes at CDI 1.4 and 1.6. When length changes were analyzed at each degree of flexion (0°, 20°, 40°, 60°, 90°), Spearman correlation analysis showed a moderate negative linear correlation for QT at CDI 1.0 ( r= −0.484; P = .002) and 1.6 ( r = −0.692; P < .0005), demonstrating constant loosening at the QT point at normal and elevated patellar height. In contrast, no differences in length were observed for MP at CDI 1.0 throughout flexion, and at CDI 1.6, there was a difference only at 0° ( P < .05). Points FC and MP at CDI 1.6 had similar length change properties to points SM and QT at CDI 1.0 ( P > .05), suggesting that distal attachments in the setting of patella alta may provide similar length changes to proximal attachmentswith normal height. Conclusion: Anisometry of the MPFC varies not only with attachment location on the extensor mechanism but also with patellar height. Increased patellar height leads to more significant changes in anisometry in the proximal MPFC attachment point as compared with the distal component. In the setting of patella alta, including a CD ratio of 1.6, the osseous attachments of the MPFC remain nearly isometric wheras the proximal half length changes increase significantly. Clinical Significance: The results of this study support the idea that the MPFC should be considered as 2 separate entities (proximal medial quadriceps tendon femoral ligament and distal medial patellofemoral ligament) owing to their unique length change properties.

Connellite from Cornwall

1885 ◽  
Vol 6 (30) ◽  
pp. 171-171 ◽  
Author(s):  
C. O. Trechmann
Keyword(s):  
General Description ◽  
Similar Length

The crystals are of a similar length, though often considerably thicker than those described by Prof. Maskelyne (Phil. Mag. Jan. 1868), and his general description applies to those under consideration.They are, however, ill-adapted for measurement, as single perfect crystals are rare. As a rule several crystals are longitudinally attached to one another, with slight radial divergence, in such a manner that it becomes difficult or impossible to discriminate between the reflections of their minute faces.

Bat Kinematics in Baseball: Implications for Ball Exit Velocity and Player Safety

2003 ◽  
Vol 19 (4) ◽  
pp. 283-294 ◽  
Author(s):  
Rochelle L. Nicholls ◽  
Bruce C. Elliott ◽  
Karol Miller ◽  
Michael Koh
Keyword(s):  
Horizontal Plane ◽  
High Speed ◽  
Movement Time ◽  
Moment Of Inertia ◽  
Moments Of Inertia ◽  
Exit Velocity ◽  
Safety Issues ◽  
Similar Length ◽  
Tip Velocity ◽  
Baseball Bats

Ball exit velocity (BEV) was measured from 17 experienced baseball hitters using wood and metal bats of similar length and mass but different moments of inertia. This research was conducted in response to safety issues for defensive players related to high BEV from metal baseball bats reported in the literature. Our purpose was to determine whether metal bats, with their lower swing moment of inertia, produce a higher linear bat tip velocity than wooden bats swung by the same players. Analysis using high-speed videography indicated significant differences in the x-component of velocity for both the proximal (metal = 5.4 m s−1; wood = 3.9 m s−1) and distal ends of the bats (metal = 37.2 m s−1; wood = 35.2 m s−1), p < 0.01. The orientation of the bats with respect to the horizontal plane was also significantly more “square” 0.005 s prior to impact (270°) for the metal (264.3°) compared with the wood bat (251.5°), p < 0.01. Mean BEV from metal bats (44.3 m s−1) was higher than the 41 m s−1 velocity which corresponds to the minimum movement time for a pitcher to avoid a ball hit in his direction (Cassidy & Burton, 1989).

Differential effects of predation risk and competition over vigilance variables and feeding success in Eurasian siskins (Carduelis spinus)

Behaviour ◽  
2013 ◽  
Vol 150 (14) ◽  
pp. 1665-1687 ◽  
Author(s):  
Jordi Pascual ◽  
Juan Carlos Senar
Keyword(s):  
Food Intake ◽  
Predation Risk ◽  
Foraging Behaviour ◽  
Interference Competition ◽  
Ecological Factors ◽  
Intake Rate ◽  
Similar Length ◽  
Feeding Success ◽  
High Predation ◽  
Food Intake Rate

Many investigations have studied the effects of predation risk and competition over vigilance and feeding success, but they have proven to be difficult to discriminate. Moreover, none of the studies that have avoided the confusion has considered all the vigilance variables, food intake rate and time spent in the foraging patch. In this study, we designed an experiment with Eurasian siskinsCarduelis spinusforaging on three bird table feeders: one with low predation risk and competition, one with low predation risk and high competition and one with high predation risk and intermediate competition. Birds responded to increasing interference competition by increasing mean scan durations (probably due to the birds having to be vigilant for both other flock members and predators) and maintaining the length of mean inter-scan durations, while they responded to increasing predation risk by reducing mean inter-scan durations (probably in order to detect the predator sooner) while maintaining similar length of mean scan durations. Birds were often ejected from the feeder or departed because of disturbances, so time spent on feeders was reduced both because of competition and predation risk. Pecking rates were affected by competition but not by predation risk. Our results clearly show that birds vigilance strategy while foraging might be very different when they are mainly concerned with scanning for predators or when they primarily monitor competing flock companions. In addition, they stress the importance of recording all the vigilance and feeding variables when studying the effect of ecological factors over the foraging behaviour of birds.

scholarly journals From graceful labellings of paths to cyclic solutions of the Oberwolfach problem

2009 ◽  
Vol 309 (14) ◽  
pp. 4877-4882 ◽  
Author(s):  
M.A. Ollis ◽  
Ambrose D. Sterr
Keyword(s):  
Oberwolfach Problem

scholarly journals Graph Products and New Solutions to Oberwolfach Problems

10.37236/539 ◽  
2011 ◽  
Vol 18 (1) ◽  
Author(s):  
Gloria Rinaldi ◽  
Tommaso Traetta
Keyword(s):  
Regular Graph ◽  
Regular Graphs ◽  
Graph Products ◽  
Simple Graphs ◽  
Oberwolfach Problem

We introduce the circle product, a method to construct simple graphs starting from known ones. The circle product can be applied in many different situations and when applied to regular graphs and to their decompositions, a new regular graph is obtained together with a new decomposition. In this paper we show how it can be used to construct infinitely many new solutions to the Oberwolfach problem, in both the classic and the equipartite case.

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