scholarly journals Genetic evaluation of Canadian dairy bulls for milking speed with an animal model

1992 ◽  
Vol 72 (1) ◽  
pp. 169-172 ◽  
Author(s):  
G. Banos ◽  
E. B. Burnside
Keyword(s):  
Animal Model ◽  
Peak Flow ◽  
Biological Significance ◽  
Flow Data ◽  
Linear Scale ◽  
Average Flow Rate ◽  
Average Flow ◽  
Brown Swiss ◽  
Time Average ◽  
Dairy Bulls

Bull proofs for milking speed were computed under an animal model for five dairy breeds. Data were subjective scores on first lactation cows from all milk recording agencies across Canada. There were 1411 Holstein, 171 Ayrshire, 85 Jersey, 31 Guernsey, and 17 Brown Swiss bulls that received official evaluations. Bull proofs were expressed on a linear scale from 1 to 9, where 9 designated bulls with the fastest milking daughters. The biological significance of these proofs was investigated using 6965 weekly cow records of total milking time, average flow rate, and peak flow. Data were on 119 Holstein cows by 41 officially proven sires. Increases in proofs of 1 point on the linear scale were associated with decreases in total milking time of 20 s and increases of 64 g min−1 and 140 g in average and peak flow, respectively. Key words: Milking speed, animal model, national evaluation, dairy bulls

scholarly journals Parameter sensitivity analysis of a lumped-parameter model of a chain of lymphangions in series

2013 ◽  
Vol 305 (12) ◽  
pp. H1709-H1717 ◽  
Author(s):  
Samira Jamalian ◽  
Christopher D. Bertram ◽  
William J. Richardson ◽  
James E. Moore
Keyword(s):  
Sensitivity Analysis ◽  
Flow Rate ◽  
Pressure Difference ◽  
Lymphatic System ◽  
Lumped Parameter Model ◽  
Average Flow Rate ◽  
Average Flow ◽  
Lumped Parameter ◽  
Time Average ◽  
A Chain

Any disruption of the lymphatic system due to trauma or injury can lead to edema. There is no effective cure for lymphedema, partly because predictive knowledge of lymphatic system reactions to interventions is lacking. A well-developed model of the system could greatly improve our understanding of its function. Lymphangions, defined as the vessel segment between two valves, are the individual pumping units. Based on our previous lumped-parameter model of a chain of lymphangions, this study aimed to identify the parameters that affect the system output the most using a sensitivity analysis. The system was highly sensitive to minimum valve resistance, such that variations in this parameter caused an order-of-magnitude change in time-average flow rate for certain values of imposed pressure difference. Average flow rate doubled when contraction frequency was increased within its physiological range. Optimum lymphangion length was found to be some 13–14.5 diameters. A peak of time-average flow rate occurred when transmural pressure was such that the pressure-diameter loop for active contractions was centered near maximum passive vessel compliance. Increasing the number of lymphangions in the chain improved the pumping in the presence of larger adverse pressure differences. For a given pressure difference, the optimal number of lymphangions increased with the total vessel length. These results indicate that further experiments to estimate valve resistance more accurately are necessary. The existence of an optimal value of transmural pressure may provide additional guidelines for increasing pumping in areas affected by edema.

scholarly journals The Effect of Toileting Position in Uroflow Curves in Young Healthy Nulliparous Women

Scientifica ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Omar Felipe Dueñas-Garcia ◽  
Maria del Pilar Matta-Gonzalez ◽  
Kylie Fuller ◽  
Wei Fang ◽  
Robert Edward Shapiro
Keyword(s):  
Pelvic Floor ◽  
Flow Rate ◽  
Pelvic Floor Disorders ◽  
Peak Flow ◽  
Maximum Flow ◽  
Average Flow Rate ◽  
Average Flow ◽  
Time To Peak ◽  
Nulliparous Women ◽  
Voided Volume

The objective of our study was to determine the effect of voiding positions on uroflow parameters in young, healthy nulliparous women with no pelvic floor disorders. Material and Methods. From December 2017 to February 2018, we performed a single-institution cross-sectional study with 30 healthy volunteers comparing uroflow curves in sitting and hovering positions. 49 participants were initially prescreened with a validated tool questionnaire for pelvic floor disorders and 30 participants who had absent symptoms were included for the final analysis. From the selected participants, demographics were collected and comparisons between the sitting and hovering position groups regarding the maximum flow rate (Qmax), average flow rate (Qave), voided volume (VV), and time to peak flow (TQmax) were conducted using either the paired t-test or the Wilcoxon rank sum test. In addition, linear regression analysis was performed to determine whether height, BMI, and age have significant impact on the log-transformed average of the pre- and postvalues of either Qmax, Qave, VV, or TQmax, as the average of these values are not normally distributed. Results. There were no statistical differences between the hovering and sitting position groups on the maximum flow rate (p=0.93), average flow rate (p=0.82), voided volume (p=0.53), and time to peak flow (p=0.82). BMI had borderline significant impact on Qave with p value = 0.0531. Conclusion. Different voiding toileting habits do not affect the most commonly used uroflow parameters in young healthy nulliparous patients. Results need to be corroborated by a larger scale study considering the small sample size of our study.

A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

scholarly journals Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design

1999 ◽  
Author(s):  
John J. Adamczyk
Keyword(s):  
Unsteady Flow ◽  
Axial Flow ◽  
Operating Conditions ◽  
Design Environment ◽  
Cfd Simulations ◽  
Average Flow ◽  
Flow Models ◽  
Time Average ◽  
Semi Empirical ◽  
Future Work

This paper summarizes the state of 3D CFD based models of the time average flow field within axial flow multistage turbomachines. Emphasis is placed on models which are compatible with the industrial design environment and those models which offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models which are free of aerodynamic input from semi-empirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures which can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines which help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time average flow models.

Modification of lymph during passage through the lymph node: effect of histamine

1983 ◽  
Vol 245 (4) ◽  
pp. H553-H559
Author(s):  
M. B. Maron
Keyword(s):  
Lymph Node ◽  
Flow Rate ◽  
Evans Blue ◽  
Protein Concentration ◽  
Lymph Flow ◽  
Blue Dye ◽  
Base Line ◽  
Average Flow Rate ◽  
Significant Modification ◽  
Average Flow

The possibility that histamine may cause the fluid and protein content of lymph to be altered during passage through the lymph node was evaluated using the canine perfused popliteal lymph node preparation. This preparation enables nodal perfusion via an afferent lymphatic (all other afferents are ligated) with artificial lymph of known composition and collection of the total efferent effluent for analysis of potential changes in volume and composition. In 11 dogs, the node was perfused at an average flow rate of 0.229 ml/min with artificial lymph containing 3.71 g/100 ml albumin. Under base-line conditions, there was no significant modification of the lymph as it passed through the node. The addition of histamine to the infusate (2-4 micrograms base/ml) caused the efferent lymph flow to increase to 0.295 ml/min (35.3% increases, P less than 0.05), the efferent protein concentration to increase to 4.32 g/100 ml (15.2% increases, P less than 0.05), and the efferent protein flux to increase from 8.40 to 12.86 mg/min (58.0% increases, P less than 0.05). The appearance of Evans blue dye-tagged protein and plasma protein fractions, not originally present in the lymph, in the efferent lymph at this time further indicated that the source of the added fluid and protein was the nodal vasculature. Mass balance calculations indicated that the addition of a fluid with a protein concentration of approximately 90% that of plasma to the lymph could account for the observed increases in efferent lymph flow and protein concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

A preliminary investigation of the freshwater red algae in streams of southern Ontario, Canada

1980 ◽  
Vol 58 (11) ◽  
pp. 1295-1318 ◽  
Author(s):  
Robert G. Sheath ◽  
Beverly J. Hymes
Keyword(s):  
Flow Rate ◽  
Red Algae ◽  
Preliminary Investigation ◽  
Average Flow Rate ◽  
Southern Ontario ◽  
Average Flow ◽  
Cell Organization ◽  
Conductivity Range ◽  
Freshwater Red Algae ◽  
The Relationship

Ten taxa of freshwater red algae have been observed in a survey of 62 streams and rivers within southern Ontario, Canada, over a period of 3 years. Five species are additions to the flora of Canada, Chroodactylon ramosum, Boldia erythrosiphon, Sirodotia tenuissima, Batrachospermum densum, and B. ectocarpum. In addition to these algae, Audouinella violacea, Sirodotia suecia, and Tuomeya fluviatilis are new observations within Ontario.Most of the Ontario red algae are restricted to streams or rivers with a minimum average flow rate of 10 m min−1. Audouinella violacea, B. moniliforme, and Lemanea fucina occur in a large number of streams which have a wide pH and conductivity range whereas S. tenuissima and B. ectocarpum are confined to one of the sites examined.Ultrastructural findings are reported concerning the cell organization of Boldia as well as the relationship between Batrachospermum plants and the "chantransia" stage. A key to the 10 taxa is included plus descriptions and a list of epiphytes of each alga are presented.

Estimates of phenotypic and genetic parameters for birth weight of Brown Swiss calves in Turkey using an animal model

2011 ◽  
Vol 44 (5) ◽  
pp. 1027-1034 ◽  
Author(s):  
A. Sahin ◽  
Z. Ulutas ◽  
A. Yilmaz Adkinson ◽  
R. W. Adkinson
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Brown Swiss

Three-dimensional dynamics and transition to turbulence in the wake of bluff objects

1992 ◽  
Vol 238 ◽  
pp. 1-30 ◽  
Author(s):  
George Em Karniadakis ◽  
George S. Triantafyllou
Keyword(s):  
Reynolds Number ◽  
Three Dimensional ◽  
Period Doubling ◽  
Reynolds Numbers ◽  
Transition To Turbulence ◽  
Two Dimensional ◽  
Near Wake ◽  
Vortex Filaments ◽  
Average Flow ◽  
Time Average

The wakes of bluff objects and in particular of circular cylinders are known to undergo a ‘fast’ transition, from a laminar two-dimensional state at Reynolds number 200 to a turbulent state at Reynolds number 400. The process has been documented in several experimental investigations, but the underlying physical mechanisms have remained largely unknown so far. In this paper, the transition process is investigated numerically, through direct simulation of the Navier—Stokes equations at representative Reynolds numbers, up to 500. A high-order time-accurate, mixed spectral/spectral element technique is used. It is shown that the wake first becomes three-dimensional, as a result of a secondary instability of the two-dimensional vortex street. This secondary instability appears at a Reynolds number close to 200. For slightly supercritical Reynolds numbers, a harmonic state develops, in which the flow oscillates at its fundamental frequency (Strouhal number) around a spanwise modulated time-average flow. In the near wake the modulation wavelength of the time-average flow is half of the spanwise wavelength of the perturbation flow, consistently with linear instability theory. The vortex filaments have a spanwise wavy shape in the near wake, and form rib-like structures further downstream. At higher Reynolds numbers the three-dimensional flow oscillation undergoes a period-doubling bifurcation, in which the flow alternates between two different states. Phase-space analysis of the flow shows that the basic limit cycle has branched into two connected limit cycles. In physical space the period doubling appears as the shedding of two distinct types of vortex filaments.Further increases of the Reynolds number result in a cascade of period-doubling bifurcations, which create a chaotic state in the flow at a Reynolds number of about 500. The flow is characterized by broadband power spectra, and the appearance of intermittent phenomena. It is concluded that the wake undergoes transition to turbulence following the period-doubling route.

Sign in / Sign up

Export Citation Format

Share Document