The Relation Among Porosity, Permeability, and Specific Surface of Chalk From the Gorm Field, Danish North Sea

1998 ◽  
Vol 1 (03) ◽  
pp. 245-251 ◽  
Author(s):  
Jeanette Mortensen ◽  
Finn Engstrom ◽  
Ida Lind
Keyword(s):  
Image Analysis ◽  
Specific Surface ◽  
North Sea ◽  
Laboratory Data ◽  
Total Porosity ◽  
Analysis Data ◽  
Air Permeability ◽  
Empirical Constant ◽  
Core Data ◽  
The Relationship

Summary The origin of the difference in the relationship between permeability and porosity for Danian and Maastrichtian chalk from the Gorm field offshore Denmark has been investigated. The investigation was based on 300 sets of core data (He-expansion porosity and air permeability) from Well Gorm N-22X. On 24 of the core plugs, the specific surface was determined by BET and, on 14 of these samples, image analysis was made. The data were rationalized by the use of the Kozeny equation and it was found that each geologic unit had a characteristic relationship among porosity, permeability, and specific surface. Furthermore, it was found that the nature of porosity (intrafossil, intergranular, etc.) had no significant influence on the air permeability, so that the permeability of the chalk can be calculated from total porosity and specific surface. Kozeny's empirical constant, c, was determined analytically from a simple porosity model and Poiseuille's law. Introduction Experience has illustrated that to a first approximation, porosity and the logarithm of permeability are well correlated in the North Sea chalk. However, different stratigraphical units have distinctly different porosity-permeability relations. For a given porosity, the permeability of chalk of Maastrichtian age is, e.g., on average, larger than the permeability of chalk of Danian age. The cause for the differences in porosity-permeability relationships between the chalk units is not well documented in literature, but the size of pores and particles, and the surface characteristics of the particles are likely controlling factors. This study was undertaken to obtain a simple model for the relationship among porosity, permeability, and specific surface for reservoir chalk irrespective of stratigraphic unit, and to evaluate the usefulness of image-analysis data relative to laboratory data. To meet this purpose, we have studied core data from a chalk field (the Gorm field) applying the Kozeny equation.

Prediction of Archie’s cementation factor from porosity and permeability through specific surface

Geophysics ◽  
2008 ◽  
Vol 73 (2) ◽  
pp. E81-E87 ◽  
Author(s):  
Casper Olsen ◽  
Thanong Hongdul ◽  
Ida Lykke Fabricius
Keyword(s):  
Physical Properties ◽  
Specific Surface ◽  
North Sea ◽  
Published Data ◽  
Simple Relationship ◽  
Porosity And Permeability ◽  
Bulk Volume ◽  
Cementation Factor ◽  
The Relationship

Based on Archie’s cementation factor as measured on North Sea chalk and on published data, we explore how the cementation factor depends on other physical properties of the chalk. A relationship between cementation factor and specific surface with respect to bulk volume is obtained for chalk. This leads to how Archie’s cementation factor may be predicted from porosity and permeability for chalk as well as for sandstone. A common relationship between cementation factor and specific surface with respect to bulk volume calculated from porosity and permeability is obtained. As an alternative, the [Formula: see text]-factor in Archie’s equation is related to specific surface with respect to bulk volume, but the relationship is less clear than the simple relationship between cementation factor and specific surface.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

scholarly journals CT pulmonary angiography in COVID-19 pneumonia: relationship between pulmonary embolism and disease severity

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Aya Yassin ◽  
Maryam Ali Abdelkader ◽  
Rehab M. Mohammed ◽  
Ahmed M. Osman
Keyword(s):  
Pulmonary Embolism ◽  
Disease Severity ◽  
Laboratory Data ◽  
Pulmonary Angiography ◽  
Significant Relation ◽  
Ct Pulmonary Angiography ◽  
Laboratory Results ◽  
Severity Of The Disease ◽  
The Relationship ◽  
D Dimer

Abstract Background Pulmonary embolism (PE) is one of the known sequels of COVID-19 infection. We aimed to assess the incidence of PE in patients with COVID-19 infection and to evaluate the relationship between the CT severity of the disease and the laboratory indicators. This was a retrospective study conducted on 96 patients with COVID-19 infection proved by positive PCR who underwent CT pulmonary angiography (CTPA) with a calculation of the CT severity of COVID-19 infection. Available patients’ complaint and laboratory data at the time of CTPA were correlated with PE presence and disease severity. Results Forty patients (41.7%) showed positive PE with the median time for the incidence of PE which was 12 days after onset of the disease. No significant correlation was found between the incidence of PE and the patients’ age, sex, laboratory results, and the CT severity of COVID-19. A statistically significant relation was found between the incidence of PE and the patients’ desaturation, hemoptysis, and chest pain. A highly significant correlation was found between the incidence of PE and the rising in the D-dimer level as well as the progressive CT findings when compared to the previous one. Conclusion CT progression and the rising in D-dimer level are considered the most important parameters suggesting underlying PE in patients with positive COVID-19 infection which is commonly seen during the second week of infection and alert the use of CT pulmonary angiography to exclude or confirm PE. This is may help in improving the management of COVID-19 infection.

scholarly journals Image data of crumb structure of bread from flour of czech spring wheat cultivars

2011 ◽  
Vol 22 (No. 4) ◽  
pp. 133-142 ◽  
Author(s):  
I. Švec ◽  
M. Hrušková
Keyword(s):  
Image Analysis ◽  
Image Data ◽  
Analysis Data ◽  
Wheat Cultivars ◽  
Rheological Measurements ◽  
Class A ◽  
Bread Volume ◽  
Class B ◽  
Crumb Structure

Abstract: Baking quality of flour from six wheat cultivars (harvest 2002 and 2003), belonging to the quality classes A and B, was evaluated using the fermented dough test. Analytical traits of kernel and flour showed differences between the classes which were confirmed by the baking test with the full-bread-formula according to Czech method. In addition to standard methods of the bread parameters description (specific bread volume and bread shape measurements) rheological measurements of penetrometer and image analysis were used in effort to differentiate wheat samples into the quality classes. The results of the baking test proved significant differences in specific bread volumes – the highest volume in class A was obtained with the cultivar Vinjet and in class B with SG-S1098 – approx. 410 and 420 ml/100 g. Although significant correlations among image analysis data and specific bread volume having been proved, any image analysis parameter did not distinguish the quality classes. Only the penetronetric measurements made with bread crumb were suitable for such purpose (r = 0.9083; for  = 0.01). Among image analysis data the total cell area of the crumb had the strongest correlation with specific bread volume (r = 0.7840; for α = 0.01).    

scholarly journals Effect of Weave Structure on Thermo-Physiological Properties of Cotton Fabrics

2015 ◽  
Vol 15 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Sheraz Ahmad ◽  
Faheem Ahmad ◽  
Ali Afzal ◽  
Abher Rasheed ◽  
Muhammad Mohsin ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Cotton Fabrics ◽  
Air Permeability ◽  
Climatic Conditions ◽  
Plain Weave ◽  
Weave Structure ◽  
Physiological Properties ◽  
The Relationship

Abstract This paper aims to investigate the relationship between fabric weave structure and its comfort properties. The two basic weave structures and four derivatives for each selected weave structure were studied. Comfort properties, porosity, air permeability and thermal resistance of all the fabric samples were determined. In our research the 1/1 plain weave structure showed the highest thermal resistance making it suitable for cold climatic conditions. The 2/2 matt weave depicted the lowest thermal resistance which makes it appropriate for hot climatic conditions.

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