Assessment of sand stabilization potential of a plant-derived biomass

2016 ◽  
Vol 23 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Dunja Perić ◽  
Paul A. Bartley ◽  
Lawrence Davis ◽  
Ali Ulvi Uzer ◽  
Cahit Gürer
Keyword(s):  
Area Ratio ◽  
Cross Sectional Area ◽  
Experimental Program ◽  
Early Age ◽  
Shear Stresses ◽  
Sectional Area ◽  
Cross Sectional ◽  
Near Surface ◽  
Total Cross Sectional Area ◽  
Dry Sand

AbstractLignin is a coproduct of biofuel and paper industries, which exhibits binding qualities when mixed with water. Lignin is an ideal candidate for a sustainable stabilization of unpaved roads. To this end, an experimental program was devised and carried out to quantify effects of lignin on compaction and early age shear strength behaviors of sand. Samples were prepared by mixing a particular type of coproduct called calcium lignosulfonate (CaL) with sand and water. Based on the extensive analyses of six series of strength tests, it was found that a normalized cohesion increased with an increasing normalized areas ratio. Normalizations were carried out by dividing the cohesion and area ratio by gravimetric CaL content whereby the area ratio was obtained by dividing the portion of the cross-sectional area occupied with lignosulfonate-water (CaL-W) paste by the total cross-sectional area. While the increase in the normalized cohesion eventually leveled out, the cohesion peaked at 6% of CaL. Thus, sand-CaL-water (S-CaL-W) mixes sustained larger shear stresses than dry sand for a range of normal stresses below the limiting normal stress. Consequently, the early age behavior indicates that adding CaL-W to sand is clearly beneficial in the near-surface applications in dry sand.

Foliage area–sapwood area relationships of Scots pine (Pinussylvestris) trees in different climates

1994 ◽  
Vol 24 (11) ◽  
pp. 2263-2268 ◽  
Author(s):  
Frank Berninger ◽  
Eero Nikinmaa
Keyword(s):  
Scots Pine ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Clear Trend ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Excess Water ◽  
Total Cross Sectional Area ◽  
Lower Ratio

Foliage mass and wood cross-sectional area were measured at different points of branches and stems within the living crown of Scots pine (Pinussylvestris L.) trees from sample plots, representing wide geographical variation. The measurements were taken during the period of annual minimum foliage mass. The needle mass: branch cross-sectional area ratio, measured below the lowest living whorl of sub-branches, differed among measured points and was normally lower for the uppermost branches, but also decreased in the lower canopy. The decrease at the lower canopy was hypothesized to reflect an excess water transport capacity resulting from the senesced needles. The lower ratio in the uppermost branches might be explained by M.H. Zimmermann's hypothesis that the water supply of foliage close to the stem is preferred. A similar trend in the branch area: stem area ratio was observed along the stem. There seemed to be strong geographic variation in the ratio between the total cross-sectional area of branches of the crown measured and the stem cross-sectional area below the living crown. The branch area: stem area ratio was higher in the southern stands, whereas there was no clear trend for the needle area: branch area ratio. The results are discussed in relation to the hydraulic architecture of trees.

scholarly journals Atrophy patterns in isolated subscapularis lesions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gernot Seppel ◽  
Andreas Voss ◽  
Daniel J. H. Henderson ◽  
Simone Waldt ◽  
Bernhard Haller ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
Subscapularis Muscle ◽  
Mri Scans ◽  
The Mean ◽  
The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

Use of Cardiac Magnetic Resonance Imaging Based Measurements of Inferior Vena Cava Cross-Sectional Area in the Diagnosis of Pericardial Constriction

2015 ◽  
Vol 66 (3) ◽  
pp. 231-237 ◽  
Author(s):  
Kate Hanneman ◽  
Paaladinesh Thavendiranathan ◽  
Elsie T. Nguyen ◽  
Hadas Moshonov ◽  
Rachel Wald ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Inferior Vena ◽  
Vena Cava ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Aortic Area

Purpose To evaluate the value of cardiac magnetic resonance imaging (MRI)–based measurements of inferior vena cava (IVC) cross-sectional area in the diagnosis of pericardial constriction. Methods Patients who had undergone cardiac MRI for evaluation of clinically suspected pericardial constriction were identified retrospectively. The diagnosis of pericardial constriction was established by clinical history, echocardiography, cardiac catheterization, intraoperative findings, and/or histopathology. Cross-sectional areas of the suprahepatic IVC and descending aorta were measured on a single axial steady-state free-precession (SSFP) image at the level of the esophageal hiatus in end-systole. Logistic regression and receiver-operating curve (ROC) analyses were performed. Results Thirty-six patients were included; 50% (n = 18) had pericardial constriction. Mean age was 53.9 ± 15.3 years, and 72% (n = 26) were male. IVC area, ratio of IVC to aortic area, pericardial thickness, and presence of respirophasic septal shift were all significantly different between patients with constriction and those without ( P < .001 for all). IVC to aortic area ratio had the highest odds ratio for the prediction of constriction (1070, 95% confidence interval [8.0-143051], P = .005). ROC analysis illustrated that IVC to aortic area ratio discriminated between those with and without constriction with an area under the curve of 0.96 (95% confidence interval [0.91-1.00]). Conclusions In patients referred for cardiac MRI assessment of suspected pericardial constriction, measurement of suprahepatic IVC cross-sectional area may be useful in confirming the diagnosis of constriction when used in combination with other imaging findings, including pericardial thickness and respirophasic septal shift.

scholarly journals Numerical Investigation of a two-inlet PVT air collector

2019 ◽  
Vol 136 ◽  
pp. 05014
Author(s):  
Zhangyang Kang ◽  
Zhaoyang Lu ◽  
Xin Deng ◽  
Qiongqiong Yao
Keyword(s):  
Heat Transfer ◽  
Single Channel ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Thermal Characteristics ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Maximum Heat

A numerical study of heat and mass transfer characteristics of a two-inlet PV/T air collector is performed. The influence of thermal characteristics and efficiency is investigated as the area ratios of inlet and outlet of the single channel with two inlets are changed. The design of the two-inlet PV/T air collector can avoid the poor heat transfer conditions of the single inlet PV/T air collector and improve the total photo-thermal efficiency. When the inlet/outlet cross-sectional area ratio is reduced, the inlet air from the second inlet enhances the convection heat transfer in the second duct and the temperature distribution is more uniform. As the cross-sectional area of the second inlet increase, the maximum heat exchange amount of the two-inlet PV/T air collector occurs between the inlet and outlet cross-sectional area ratio L=0.645 and L=0.562.

scholarly journals Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot

2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Gregory T. Adamson ◽  
Doff B. McElhinney ◽  
Yulin Zhang ◽  
Jeffrey A. Feinstein ◽  
Lynn F. Peng ◽  
...  
Keyword(s):  
Tetralogy Of Fallot ◽  
Surgical Outcomes ◽  
Pulmonary Circulation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Major Aortopulmonary Collateral Arteries ◽  
Collateral Arteries ◽  
Total Cross Sectional Area ◽  
Aortopulmonary Collateral

Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross‐sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross‐sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.

Genetic Effects on Skeletal Mechanosensitivity in Mice

2002 ◽  
Author(s):  
Charles H. Turner ◽  
Alexander G. Robling
Keyword(s):  
Mechanical Loading ◽  
Cross Sections ◽  
Inbred Mouse ◽  
Cross Sectional Area ◽  
Mouse Strains ◽  
Sectional Area ◽  
Mineral Density ◽  
Bone Apposition ◽  
Cross Sectional ◽  
Total Cross Sectional Area

The accumulation of bone mass during growth can be enhanced by environmental factors such as mechanical loading (exercise) or calcium intake, but 60–70% of the variance in adult bone mineral density (BMD) is explained by heredity. Consequently, understanding the signaling pathways targeted by the genes governing bone accumulation holds perhaps the greatest potential in reducing fracture incidence later in life. Rodent models are particularly useful for studying the genetics of skeletal traits. Of the available inbred mouse strains, three in particular have been studied extensively in skeletal genetics: C57BL/6, DBA/2, and C3H/He. The C57BL/6 strain is characterized by low BMD and large total cross-sectional area (CSA) in the midshaft femur; the C3H/He strain exhibits very high femoral BMD and a smaller femoral CSA than the C57BL/6 mice; and DBA/2 mice have moderately high femoral BMD and a very small midshaft femur CSA. Mechanical loading of the skeleton during growth can substantially enhance periosteal bone apposition, and ultimately produce a diaphyseal cross section with enlarged area. Therefore we hypothesized that the mouse strain with greater femoral cross-sectional area (C57BL/6) might have a genetic predisposition for greater mechanosensitivity than mice with smaller cross sections (C3H/He and DBA/2).

Conservation of bronchiolar wall area during constriction and dilation of human airways

1997 ◽  
Vol 82 (3) ◽  
pp. 954-958 ◽  
Author(s):  
R. W. Mitchell ◽  
E. Rühlmann ◽  
H. Magnussen ◽  
N. M. Muñoz ◽  
A. R. Leff ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Contraction ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Wall Area ◽  
Total Cross Sectional Area ◽  
Human Airways ◽  
Contraction And Relaxation

Mitchell, R. W., E. Rühlmann, H. Magnussen, N. M. Muñoz, A. R. Leff, and K. F. Rabe. Conservation of bronchiolar wall area during constriction and dilation of human airways. J. Appl. Physiol. 82(3): 954–958, 1997.—We assessed the effect of smooth muscle contraction and relaxation on airway lumen subtended by the internal perimeter ( A i) and total cross-sectional area ( A o) of human bronchial explants in the absence of the potential lung tethering forces of alveolar tissue to test the hypothesis that bronchoconstriction results in a comparable change of A iand A o. Luminal area (i.e., A i) and A owere measured by using computerized videomicrometry, and bronchial wall area was calculated accordingly. Images on videotape were captured; areas were outlined, and data were expressed as internal pixel number by using imaging software. Bronchial rings were dissected in 1.0- to 1.5-mm sections from macroscopically unaffected areas of lungs from patients undergoing resection for carcinoma, placed in microplate wells containing buffered saline, and allowed to equilibrate for 1 h. Baseline, A o[5.21 ± 0.354 (SE) mm2], and A i(0.604 ± 0.057 mm2) were measured before contraction of the airway smooth muscle (ASM) with carbachol. Mean A inarrowed by 0.257 ± 0.052 mm2in response to 10 μM carbachol ( P = 0.001 vs. baseline). Similarly, A onarrowed by 0.272 ± 0.110 mm2in response to carbachol ( P = 0.038 vs. baseline; P = 0.849 vs. change in A i). Similar parallel changes in cross-sectional area for A iand A owere observed for relaxation of ASM from inherent tone of other bronchial rings in response to 10 μM isoproterenol. We demonstrate a unique characteristic of human ASM; i.e., both luminal and total cross-sectional area of human airways change similarly on contraction and relaxation in vitro, resulting in a conservation of bronchiolar wall area with bronchoconstriction and dilation.

CORRELATION BETWEEN BODY HABITUS AND CROSS-SECTIONAL AREA OF RIBS

1965 ◽  
Vol 43 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Hideaki Takahashi ◽  
Harold M. Frost
Keyword(s):  
Sampling Site ◽  
Correlation Coefficients ◽  
Correlation Study ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Body Habitus ◽  
Normal People ◽  
Total Cross Sectional Area ◽  
The Relationship

A correlation study was performed of the relationship between the total cross-sectional area of the fifth, sixth, or seventh rib in its middle third, and the height, weight, and sex of its owner. The study involved 115 metabolically normal people and yielded high correlation coefficients between the calculated and observed total rib cross-sectional areas of 60 males and 55 females. It is suggested that the total cross-sectional area at a standard bone sampling site be used as a basis for normalizing measures of the severity of osteoporosis. This would allow one to make improved comparisons of the severity of osteoporosis between persons of different body habitus and sex.

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