scholarly journals Liquid dispensing in the adhesive hairy pads of dock beetles

2020 ◽  
Vol 17 (166) ◽  
pp. 20200024 ◽  
Author(s):  
Antonio Iazzolino ◽  
Uroš Cerkvenik ◽  
Youness Tourtit ◽  
Auxane Ladang ◽  
Philippe Compère ◽  
...  
Keyword(s):  
Hydraulic Resistance ◽  
Contact Time ◽  
Contact Phase ◽  
Liquid Transport ◽  
Contact Zones ◽  
Secretion Pathway ◽  
Cumulative Volume ◽  
Capillary Bridges ◽  
Surface Contact ◽  
Hair Surface

Many insects can climb on smooth inverted substrates using adhesive hairy pads on their legs. The hair–surface contact is often mediated by minute volumes of liquid, which form capillary bridges in the contact zones and aid in adhesion. The liquid transport to the contact zones is poorly understood. We investigated the dynamics of liquid secretion in the dock beetle Gastrophysa viridula by quantifying the volume of the deposited liquid footprints during simulated walking experiments. The footprint volume increased with pad–surface contact time and was independent of the non-contact time. Furthermore, the footprint volume decreased to zero after reaching a threshold cumulative volume (approx. 30 fl) in successive steps. This suggests a limited reservoir with low liquid influx. We modelled our results as a fluidic resistive system and estimated the hydraulic resistance of a single attachment hair of the order of MPa · s/fl. The liquid secretion in beetle hairy pads is dominated by passive suction of the liquid during the contact phase. The high calculated resistance of the secretion pathway may originate from the nanosized channels in the hair cuticle. Such nanochannels presumably mediate the transport of cuticular lipids, which are chemically similar to the adhesive liquid.

scholarly journals Assessing Plyometric Ability during Vertical Jumps Performed by Adults and Adolescents

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 132 ◽  
Author(s):  
Brandon Snyder ◽  
Shawn Munford ◽  
Chris Connaboy ◽  
Hugh Lamont ◽  
Shala Davis ◽  
...  
Keyword(s):  
Contact Time ◽  
Analysis Data ◽  
Adolescent Male ◽  
Ground Contact ◽  
Strength Index ◽  
Basketball Players ◽  
Contact Phase ◽  
Adult Men ◽  
Drop Jumps ◽  
Vertical Jumps

The purpose of this study was to compare different methods for assessing plyometric ability during countermovement (CMJ) and drop jumps (DJ) in a group of adults and adolescents. Ten resistance-trained adult men (age: 22.6 ± 1.6 years) and ten adolescent male basketball players (age: 16.5 ± 0.7 years) performed a CMJ and a DJ from a height of 0.40 m. Jump height (JH), contact time, normalized work (WNORM), and power output (PONORM) during the absorption and propulsion phases were calculated from force platforms and 3-D motion analysis data. Plyometric ability was assessed using the modified reactive strength index (RSIMOD during CMJ) and the reactive strength index (RSI during DJ) as well as three indices using propulsion time, propulsion work (PWI), and propulsion power. Adults jumped significantly higher than adolescents (mean difference [MD]: 0.05 m) while JH (MD: 0.05 m) and ground contact time (MD: 0.29 s) decreased significantly from CMJ to DJ. WNORM (MD: 4.2 J/kg) and PONORM (MD: 24.2 W/kg) during the absorption phase of CMJ were significantly less than these variables during the propulsion phases of the jumps. The reactive strength index variants increased significantly from the CMJ to DJ (MD: 0.23) while all other plyometric indices decreased significantly. Neither RSIMOD nor RSI contributed significantly to the prediction of JH during CMJ and DJ, respectively, while PWI was able to explain ≥68% of the variance in JH. Variants of the reactive strength index do not reflect the changes in mechanical variables during the ground contact phase of CMJ and DJ and may not provide an accurate assessment of plyometric ability during different vertical jumps.

scholarly journals The topographic characteristics of contact zones in the surface contact formed in the grinding process

Mechanik ◽  
2017 ◽  
Vol 90 (10) ◽  
pp. 921-923
Author(s):  
Wojciech Kacalak ◽  
Filip Szafraniec
Keyword(s):  
Grinding Process ◽  
Contact Zones ◽  
Surface Contact ◽  
Topographic Characteristics

In the publication a topographic characteristics of the contact zones in the contact joints for the surfaces formed in the grinding process was presented.

Tri‐axial all‐metal inertial microswitch with compliant stationary electrodes to prolong contact time

2014 ◽  
Vol 9 (8) ◽  
pp. 514-518 ◽  
Author(s):  
Wenguo Chen ◽  
Zhaoyu Wang ◽  
Yan Wang ◽  
Zhuoqing Yang ◽  
Guifu Ding ◽  
...  
Keyword(s):  
Contact Time

Tailoring Communications for Primary Care Settings

1998 ◽  
Vol 37 (02) ◽  
pp. 171-178 ◽  
Author(s):  
B. Glassman ◽  
B. K. Rimer
Keyword(s):  
Primary Care ◽  
Health Professionals ◽  
Contact Time ◽  
Behavioral Changes ◽  
Patient Specific ◽  
Specific Information ◽  
Medical Settings ◽  
Primary Care Settings ◽  
Professional Contact ◽  
Tailored Communications

AbstractIn more and more medical settings, physicians have less and less time to be effective communicators. To be effective, they need accurate, current information about their patients. Tailored health communications can facilitate positive patient-provider communications and foster behavioral changes conducive to health. Tailored communications (TCs) are produced for an individual based on information about that person. The focus of this report is on tailored print communications (TPCs). TPCs also enhance the process of evaluation, because they require a database and the collection of patient-specific information. We present a Tailoring Model for Primary Care that describes the steps involved in creating TPCs. We also provide examples from three ongoing studies in which TPCs are being used in order to illustrate the kinds of variables used for tailoring the products that are developed and how evaluation is conducted. TPCs offer opportunities to expand the reach of health professionals and to give personalized, individualized massages in an era of shrinking professional contact time.

A Modified Thromboplastin Screening Test

1961 ◽  
Vol 06 (03) ◽  
pp. 492-497 ◽  
Author(s):  
Janet C. Macpherson ◽  
R. M Hardisty
Keyword(s):  
Standard Method ◽  
Comparative Studies ◽  
Screening Test ◽  
Incubation Mixture ◽  
Surface Contact ◽  
Modified Test ◽  
Effect Of Surface

SummaryA modification of the thromboplastin screening test of Hicks and Pitney is described, in which the effect of surface contact on the test plasma is controlled by the addition of a suspension of kaolin to the incubation mixture before recalcification.Comparative studies show the modified test to give more reproducible results than the standard method.

The Contact Phase of Blood Coagulation in Diabetes Mellitus and in Patients with Vasculopathy

1984 ◽  
Vol 52 (03) ◽  
pp. 221-223 ◽  
Author(s):  
M Christe ◽  
P Gattlen ◽  
J Fritschi ◽  
B Lämmle ◽  
W Berger ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Negative Correlation ◽  
Factor Xii ◽  
C1 Inhibitor ◽  
High Molecular Weight Kininogen ◽  
Contact Phase ◽  
Α2 Macroglobulin

SummaryThe contact phase has been studied in diabetics and patients with macroangiopathy. Factor XII and high molecular weight kininogen (HMWK) are normal. C1-inhibitor and also α2-macroglobulin are significantly elevated in diabetics with complications, for α1-macroglobulin especially in patients with nephropathy, 137.5% ± 36.0 (p <0.001). C1-inhibitor is also increased in vasculopathy without diabetes 113.2 ± 22.1 (p <0.01).Prekallikrein (PK) is increased in all patients’ groups (Table 2) as compared to normals. PK is particularly high (134% ± 32) in 5 diabetics without macroangiopathy but with sensomotor neuropathy. This difference is remarkable because of the older age of diabetics and the negative correlation of PK with age in normals.

Brahmi legends on Umayyad Fulus: Interrogating local minting practices and numismatic transculturation in Gandhara (ca. 750 CE)

Afghanistan ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 153-165
Author(s):  
Waleed Ziad
Keyword(s):  
Base Metal ◽  
Late Antiquity ◽  
Eighth Century ◽  
Political Authority ◽  
Unusual Feature ◽  
Complex Relationship ◽  
Contact Zones ◽  
Confessional Identity ◽  
Derivatives Of

This paper concerns a historically significant find of copper derivatives of Umayyad post-reform fulus from Gandhara, probably minted in the mid-eighth century under Turk Shahi sovereignty (c. 667–875). The coins share an unusual feature: two Brahmi aksharas on an Umayyad AE prototype, inversely oriented to a partially-corrupted Arabic legend. These base metal coins represent perhaps the only known caliphal imitative varieties issued by moneyers beyond the eastern limits of Umayyad and Abbasid sovereignty. They have the potential to inform our understanding of the complex relationship between political authority, confessional identity, and coin typology in late antiquity – particularly within early “Hindu”– “Muslim” contact zones. Moreover, they provide invaluable clues into the circulatory regimes of Umayyad coinage.

MODELING THE HYDRAULIC CHARACTERISTICS OF DRAIN VALVE AND BURST FITTING OF AN AIRCRAFT ACCIDENT-RESISTANT FUEL SYSTEM

2020 ◽  
Vol 7 (3) ◽  
pp. 37-44
Author(s):  
KONSTANTIN NAPREENKO ◽  
◽  
ROMAN SAVELEV ◽  
ALEKSEY TROFIMOV ◽  
ANNA LAMTYUGINA ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic Resistance ◽  
Hydraulic Calculation ◽  
Fuel System ◽  
Hydraulic Characteristics ◽  
System A ◽  
Ansys Cfx ◽  
Calculation Results ◽  
Scale Experiment ◽  
Aircraft Accident

The article discusses methods for determining the hydraulic resistance of units of an accident-resistant fuel system. A detailed description of the need to create such fuel systems for modern helicopters is given. The development of such systems today is impossible without the use of the method of mathematical modeling, which allows to qualitatively solve problems arising in the design process. To obtain accurate research results, it is necessary to have a complete description of all elements and assemblies of the system. Methods for determining the hydraulic characteristics of AFS elements using the drag coefficient, reference literature and CFD codes are considered. As the investigated AFS units, a drain valve and burst fitting were studied in the article. A hydraulic calculation of these AFS elements ware performed, the simulation results are presented in the ANSYS CFX software package. Also as the calculation results of bursting fitting, the pressure distribution fields of full and static pressure, velocity and streamlines are also shown. An experimental setup for validating the results obtained using the mathematical modeling method is considered, as well as a methodology for conducting a full-scale experiment to determine the hydraulic resistance of the unit. Materials have been prepared for inclusion in a one-dimensional mathematical model of an accident-resistant fuel system.

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