scholarly journals Applicability of the photogrammetry technique to determine the volume and the bulk density of small soil aggregates

Soil Research ◽  
2016 ◽  
Vol 54 (3) ◽  
pp. 354 ◽  
Author(s):  
D. Moret-Fernández ◽  
B. Latorre ◽  
C. Peña ◽  
C. González-Cebollada ◽  
M. V. López
Keyword(s):  
Strong Correlation ◽  
General Trend ◽  
Conservation Tillage ◽  
Soil Aggregates ◽  
Three Dimensional ◽  
Digital Camera ◽  
Aggregate Size ◽  
Soil Disturbance ◽  
The Relationship ◽  
Dimensional Surface

Aggregate density (ρ) is defined as the relationship between the mass and the volume occupied by an aggregate. Previous studies have characterised ρ on large to medium-sized soil aggregates (>4 mm diameter); however, little information is available for smaller aggregates (<4 mm). The objective of this study was to test the viability of the photogrammetry (PHM) technique to determine the volume and subsequent ρ of small soil aggregates (1–8 mm diameter). The method uses a standard digital camera that photographs a rotating aggregate and reconstructs its three-dimensional surface and the corresponding volume. To validate the method, the volume estimated with PHM on rough stones of different sizes (1–16 mm diameter) was compared with the corresponding volume measured by the Archimedes’ principle. The method was tested on soil aggregates 1–8 mm in diameter, collected from two sites under conventional and conservation tillage treatments. The strong correlation (R2 > 0.99, P < 0.0001) between the volumes estimated on rough stones with the PHM and Archimedes methods demonstrates that this technique can be satisfactorily used to estimate the volume and, consequently, the ρ of small soil aggregates. The results showed an increase in ρ with decreasing aggregate size. A general trend of increasing ρ with the degree of soil disturbance by tillage was also observed.

Research of Binocular Positioning Mathematical Model Based on the Least Square Method

2011 ◽  
Vol 50-51 ◽  
pp. 473-477 ◽  
Author(s):  
Chun Feng Liu ◽  
Xiao Li Meng ◽  
Huan Cheng Zhang
Keyword(s):  
Relative Position ◽  
Three Dimensional ◽  
Digital Camera ◽  
Least Square Method ◽  
Absolute Error ◽  
Least Square ◽  
Specific Data ◽  
Centroid Algorithm ◽  
Three Dimensional Coordinate ◽  
The Relationship

By giving a centroid algorithm to extract pixel coordinates of each circle in the center of a circle under the coordinates, through the coordinate transformation the image coordinates can be obtained. Based on the data obtained from above to verify the model, from the specific data of the relative error, absolute error and error propagation theory to discuss the algorithm accuracy and stability. Finally using the least square method, according to the mean square error criteria for the establishment of a minimum of three-dimensional coordinate system fixed relative position of two cameras, binocular positioning mathematical models and by discussing the nature of matrix and the relationship between the relative position of the camera to calibrate the binocular digital camera.

EVALUATION FOR RESIDUAL AXIAL FORCE OF CORRODED HIGH TENSILE BOLTS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Ryoichi Satake ◽  
Katashi Fujii ◽  
Yumi Mori
Keyword(s):  
Axial Force ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Shape ◽  
Thickness Reduction ◽  
Long Time ◽  
Force Reduction ◽  
The Relationship ◽  
Dimensional Surface

This paper presents a method for evaluating the residual axial force of corroded high strength bolts in experiments, and analysis measuring the axial force of corroded high strength bolts. In order to reproduce the axial force reduction due to corrosion, the test specimens were made by cutting the bolt head widthwise or the height-wise with an initial axial force. The curve of axial force lowering is prepared with a reduced thickness in height and width of bolts as a parameter. Therefore, the residual axial force can be estimated by the thickness reduction of bolt. Moreover, we measured the residual axle force of real corroded high strength bolts, taken from a bridge removed from service for a long time, and inspected an axis drop curve. In order to classify corrosion shapes, we measured the three-dimensional surface shape of corroded high strength bolts without contact, and considered the relationship between the surface shape of corroded high strength bolts and the axial force reduction.

Soil aggregate size affects C sequestration and microorganisms inside aggregate under straw addition

2020 ◽  
Author(s):  
Jinjing Lu ◽  
Sheng ping Li ◽  
Xueping Wu ◽  
Aurore Degre
Keyword(s):  
Large Scale ◽  
Soil Aggregates ◽  
Aggregate Size ◽  
C Sequestration ◽  
Soil Aggregate ◽  
Basic Unit ◽  
Size Fractions ◽  
Soil Microbial ◽  
Relationship Of ◽  
The Relationship

&lt;p&gt;As the basic unit of soil, aggregates are considered as a stable soil organic ( SOC ) pool. Changes in organic subtract due to straw addition induce variations in soil microbial community or activity, which may effect the C sequestration in aggregates. Most of the previous studies on soil microorganisms assessment was done at large scale i.e. larger quantities of soil, however, few studies on SOC is known in aggregate size fractions. This study investigated the effects of soil aggregate size on the distribution of microorganism and SOC, and the relationship of microorganism and C sequestration inside aggregate size fractions with &lt;sup&gt;13&lt;/sup&gt;C-labelled straw addition. Soil samples were collected from 0-15 cm and classified into 5 aggregates sizes classes ( &amp;#65310;5 mm, 2-5 mm, 1-2 mm, 0.25-1 mm and &amp;#65308;0.25 mm ), and the graded aggregates were incubated for 180 days at 20&amp;#160;&amp;#176;C, with or without&amp;#160;&lt;sup&gt;13&lt;/sup&gt;C-labelled straw residue. The incorporation of &lt;sup&gt;13&lt;/sup&gt;C into the five aggregate size fractions was analyzed.&lt;/p&gt;&lt;p&gt;After incubation, the SOC, DOC and ROC contents were increased more rapidly and significantly in aggregate ( &amp;#65310;5 mm ) than that in aggregate ( &amp;#65308;5 mm ) under straw addition, with the same trend of new carbon derived from straw. The total PLFAs was increased most significantly in aggregate ( &amp;#65310;5 mm ), especially fungi and negative bacteria ( G- ), while the positive bacteria ( G+ ) increased slightly in aggregate ( &amp;#65308;0.25 mm ), with no significant change in total PLFAs. The proportion of bacteria in total microorganism increased gradually, as the aggregate size increased in straw treatment. The results imply that aggregate ( &amp;#65310;5 mm ) have more space for C sequestration and greater contribution to new carbon turnovering in soil than other small aggregates, and it gradually tended to be bacterial with the enrichment of carbon. In addition, the SOC contents were strongly related to the amount of fungi and G- in aggregate ( &amp;#65308;5 mm ), while related to G+ in aggregate ( &amp;#65308;0.25 mm ) under straw addition.&lt;/p&gt;

Enhancement of Heat Transfer Performance in Nuclear Fuel Rod Using Nanofluids and Surface Roughness Technique

2015 ◽  
Author(s):  
Kang Liu ◽  
Titan C. Paul ◽  
Leo A. Carrilho ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Nuclear Fuel ◽  
Three Dimensional ◽  
Pressurized Water ◽  
Bulk Fluid ◽  
Fuel Rod ◽  
Dimensional Surface

The experimental investigations were carried out of a pressurized water nuclear reactor (PWR) with enhanced surface using different concentration (0.5 and 2.0 vol%) of ZnO/DI-water based nanofluids as a coolant. The experimental setup consisted of a flow loop with a nuclear fuel rod section that was heated by electrical current. The fuel rod surfaces were termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (diamond shaped blocks). The variation in temperature of nuclear fuel rod was measured along the length of a specified section. Heat transfer coefficient was calculated by measuring heat flux and temperature differences between surface and bulk fluid. The experimental results of nanofluids were compared with the coolant as a DI-water data. The maximum heat transfer coefficient enhancement was achieved 33% at Re = 1.15 × 105 for fuel rod with three-dimensional surface roughness using 2.0 vol% nanofluids compared to DI-water.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

scholarly journals Association of bisphenol A with puberty timing: a meta-analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hui Meng ◽  
Yunping Zhou ◽  
Yunxia Jiang
Keyword(s):  
Bisphenol A ◽  
Confidence Intervals ◽  
Random Effects ◽  
Strong Correlation ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Study Heterogeneity ◽  
The Relationship ◽  
Prevalence Ratios

AbstractObjectivesThe results of existing studies on bisphenol A (BPA) and puberty timing did not reach a consensus. Thereby we performed this meta-analytic study to explore the association between BPA exposure in urine and puberty timing.MethodsMeta-analysis of the pooled odds ratios (OR), prevalence ratios (PR) or hazards ratios (HR) with 95% confidence intervals (CI) were calculated and estimated using fixed-effects or random-effects models based on between-study heterogeneity.ResultsA total of 10 studies involving 5621 subjects were finally included. The meta-analysis showed that BPA exposure was weakly associated with thelarche (PR: 0.96, 95% CI: 0.93–0.99), while no association was found between BPA exposure and menarche (HR: 0.99, 95% CI: 0.89–1.12; OR: 1.02, 95% CI: 0.73–1.43), and pubarche (OR: 1.00, 95% CI: 0.79–1.26; PR: 1.00, 95% CI: 0.95–1.05).ConclusionsThere was no strong correlation between BPA exposure and puberty timing. Further studies with large sample sizes are needed to verify the relationship between BPA and puberty timing.

scholarly journals DISCRETE AND CONTINUUM APPROACHES TO THREE-DIMENSIONAL QUANTUM GRAVITY

1991 ◽  
Vol 06 (39) ◽  
pp. 3591-3600 ◽  
Author(s):  
HIROSI OOGURI ◽  
NAOKI SASAKURA
Keyword(s):  
Gauge Theory ◽  
Moduli Space ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Analogue Model ◽  
Gauge Invariant ◽  
Invariant Functions ◽  
Dimensional Lattice ◽  
Chern Simons ◽  
Dimensional Surface

It is shown that, in the three-dimensional lattice gravity defined by Ponzano and Regge, the space of physical states is isomorphic to the space of gauge-invariant functions on the moduli space of flat SU(2) connections over a two-dimensional surface, which gives physical states in the ISO(3) Chern–Simons gauge theory. To prove this, we employ the q-analogue of this model defined by Turaev and Viro as a regularization to sum over states. A recent work by Turaev suggests that the q-analogue model itself may be related to an Euclidean gravity with a cosmological constant proportional to 1/k2, where q=e2πi/(k+2).

Genetic variations of SCNA7 and blood pressure potassium interaction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Delgado ◽  
M Delgado-Lelievre ◽  
D Lelievre ◽  
A Delgado-Almeida
Keyword(s):  
Blood Pressure ◽  
Strong Correlation ◽  
Genetic Variations ◽  
Sodium Potassium ◽  
Blood Institute ◽  
Urine Creatinine ◽  
National Heart Lung ◽  
Gated Channel ◽  
K Concentration ◽  
The Relationship

Abstract Introduction The sodium voltage-gated channel alpha subunit 7 (SCN7A) has been associated to renal Na regulation and hypertension. This study explores the relationship between blood pressure (BP) and urinary overnight Na/K ratio (UONaK) in hypertensives (HT) and normotensive (NT) subjects from from National Heart, Lung and Blood Institute funded, Family Blood Pressure Program (FBPP) that were genotyped for 3 SNPs for SCN7A: CV2161217, CV 356958 and CV433036. Hypothesis Genetic variations in the SCNA7 are differently associated to BP and UONaK in HT and NT. Methods 1,749 subjects genotyped for SCN7A SNPs CV2161217, CV 356958 and CV433036 were analyzed from FBPP. Subjects with diastolic BP (DBP) ≥80 or systolic BP (SBP) ≥130 mmHg were classified HTN; subjects with SBP &lt;130 and DBP &lt;80 mmHg were classified as NT. UONAK was calculated by dividing overnight Na by K concentration. Correlation analysis done with partial variables (use of antihypertensive drug, use of diuretics, overnight urine creatinine). Results For the CV2161217, HTN group (n=1,030), 52% had C/C, 39% C/T and 9% T/T. In NT group (n=719), 52% had C/C, 38% C/T and 10% T/T. In the HT group, subjects with CC genotype showed strong correlation between DBP and UONaK (Fig 1a) while no significant correlation with SBP. Those with CT genotype maintained the correlation between SBP and UONaK (r=0.10, p=0.03) with no correlation with SBP. The TT showed no correlation between UONaK and SBP or DBP. In the NT, subjects with TT genotype showed strong correlation between DBP and UONaK (Fig 1b) and with SB (r=0.256, p=0.03). Those with CT or TT genotypes showed no correlation between UONaK and SBP or DBP. Similar finding were obtained for CV356958 SNP; no similar association was observed in the CV433036 SNP. Conclusions Subjects with the genetic variations in the SCNA7, such as CV2161217 and CV 356958 SNPs, showed significant correlation between blood pressure and overnight urinary sodium potassium. This finding could have important implications in non dipping status observed in some hypertensive patients. Funding Acknowledgement Type of funding source: None

scholarly journals A Field Measurement Based Wind Characteristics Analysis of a Typhoon in Near-Ground Boundary Layer

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 873
Author(s):  
Dandan Xia ◽  
Liming Dai ◽  
Li Lin ◽  
Huaifeng Wang ◽  
Haitao Hu
Keyword(s):  
Turbulence Intensity ◽  
Field Measurement ◽  
Three Dimensional ◽  
Wind Data ◽  
Statistical Characteristics ◽  
Gust Factor ◽  
Characteristics Analysis ◽  
Wind Characteristics ◽  
The Mean ◽  
The Relationship

The field measurement was conducted to observe the wind field data of West Pacific typhoon “Maria” in this research. With the application of ultrasonic anemometers installed in different heights (10 m, 80 m, 100 m) of the tower, the three dimensional wind speed data of typhoon “Maria” was acquired. In addition, vane-type anemometers were installed to validate the accuracy of the wind data from ultrasonic anemometers. Wind characteristics such as the mean wind profile, turbulence intensity, integral length scale, and wind spectrum are studied in detail using the collected wind data. The relationship between the gust factor and turbulence intensity was also studied and compared with the existing literature to demonstrate the characteristics of Maria. The statistical characteristics of the turbulence intensity and gust factor are presented. The corresponding conclusion remarks are expected to provide a useful reference for designing wind-resistant buildings and structures.

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