Effects of gender-related geometrical characteristics of aorta–iliac bifurcation on hemodynamics and macromolecule concentration distribution

2008 ◽  
Vol 51 (23-24) ◽  
pp. 5542-5551 ◽  
Author(s):  
Mehrzad Khakpour ◽  
Kambiz Vafai
1994 ◽  
Vol 144 ◽  
pp. 387-389
Author(s):  
P. Duchlev ◽  
Z. Mouradian ◽  
V. N. Dermendjiev

AbstractTwo basic geometric quantities - the filament length and the height above the limb of the long-lived filaments are studied. Some statistical relations are obtained.


1977 ◽  
Vol 38 (04) ◽  
pp. 0850-0862 ◽  
Author(s):  
Robert G. Schaub ◽  
Ronald Sande ◽  
Kenneth M. Meyers

SummaryPermanent ligation of the feline aorta at the iliac bifurcation is followed by rapid opening of pre-existing collateral blood vessels. However, if ligation is combined with formation of a clot, these protective collateral vessels do not function. This study was undertaken to determine if drugs which alter serotonin function can improve collateral blood flow after arterial thrombosis. Permanent ligations were placed at the iliac bifurcation, circumflex iliac and sixth lumbar arteries in all cats. A clot was produced in the aorta of 27 cats by injection of 0.1 ml of thromboplastin. Ligated clot-occluded cats were untreated (10); had blood serotonin depleted using a single dose of reserpine (0.1 mg/kg i. m.) followed by para-chlorophenylanine (p-CPA) (100 mg/kg orally) every 3 days (9) ; or were treated prior to surgery with a serotonin antagonist cinanserin HC1 (4 mg/kg i. v.) (8). Control cats (18) were acutely ligated. 9 of these cats were untreated, 5 were cinanserin HC1-treated, and 4 were reserpine/p-CPA-treated. Extent of collateral development was assessed by aortograms 3 days after occlusion and by neurologic rating. Aortograms of acutely ligated cats indicated a significant collateral blood flow around the segment of ligated aorta, while ligated clot-occluded cats had a severely depressed hind-limb perfusion. Reserpine/p-CPA-treated ligation clot-occluded cats had aortograms similar to acutely ligated cats. The cinanserin HC1-treated ligation clot-occluded cats had aortograms which indicated hind-limb perfusion was not as adequate as the acutely ligated cats. However, the perfusion of these animals was improved over untreated ligation clot-occluded cats. Neurologic rating correlated with aortograms. These results suggest: 1) the clinical consequences of arterial thrombosis cannot be entirely attributed to mechanical occlusion of an artery, but may be due to depression of protective collateral blood flow induced by thrombosis, 2) serotonin is an important factor in this depression of collateral blood flow, and 3) isolation of the factors responsible for collateral inhibition could permit the development of therapeutic interventions.


2019 ◽  
Vol 63 (5) ◽  
pp. 50402-1-50402-9 ◽  
Author(s):  
Ing-Jr Ding ◽  
Chong-Min Ruan

Abstract The acoustic-based automatic speech recognition (ASR) technique has been a matured technique and widely seen to be used in numerous applications. However, acoustic-based ASR will not maintain a standard performance for the disabled group with an abnormal face, that is atypical eye or mouth geometrical characteristics. For governing this problem, this article develops a three-dimensional (3D) sensor lip image based pronunciation recognition system where the 3D sensor is efficiently used to acquire the action variations of the lip shapes of the pronunciation action from a speaker. In this work, two different types of 3D lip features for pronunciation recognition are presented, 3D-(x, y, z) coordinate lip feature and 3D geometry lip feature parameters. For the 3D-(x, y, z) coordinate lip feature design, 18 location points, each of which has 3D-sized coordinates, around the outer and inner lips are properly defined. In the design of 3D geometry lip features, eight types of features considering the geometrical space characteristics of the inner lip are developed. In addition, feature fusion to combine both 3D-(x, y, z) coordinate and 3D geometry lip features is further considered. The presented 3D sensor lip image based feature evaluated the performance and effectiveness using the principal component analysis based classification calculation approach. Experimental results on pronunciation recognition of two different datasets, Mandarin syllables and Mandarin phrases, demonstrate the competitive performance of the presented 3D sensor lip image based pronunciation recognition system.


1992 ◽  
Vol 23 (1) ◽  
pp. 1-12
Author(s):  
Ram Raj Vinda ◽  
Raja Ram Yadava ◽  
Naveen Kumar

Analytical solutions converging rapidly at large and small values of times have been obtained for two mathematical models which describe the concentration distribution of a non reactive pollutant from a point source against the flow in a horizontal cross-section of a finite saturated shallow aquifer possessing uniform horizontal groundwater flow. Zero concentration or the conditions in which the flux across the extreme boundaries are proportional to the respective flow components are applied. The effects of flow and dispersion on concentration distribution are also discussed.


1986 ◽  
Vol 21 (3) ◽  
pp. 332-343 ◽  
Author(s):  
C.H. Chan ◽  
Y.L. Lau ◽  
B.G. Oliver

Abstract The concentration distribution of hexachlorobutadiene (HCBD), pentachloro-benzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in water samples from transects across the upper and lower St. Clair River and the upper Detroit River were determined on four occasions in 1985. The data show a plume of these contaminants from the Sarnia industrial area. The fluxes and concentration profiles of the contaminants at Port Lambton have been modelled success fully using a simple transverse mixing model. A study on the chemical partitioning between the “dissolved” and “suspended sediment” phases shows that an important contaminant fraction is carried in the river by the suspended solids, particularly for lipophilie compounds such as HCB and OCS,


2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.


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