144 research outputs found
Magnetic Resonance Free Induction Decay of Geological Porous Materials in the Single-Exponential and Non-Exponential Regimes
No full textThis dataset contains 1H magnetic resonance free induction decay of three rock samples: (a) Berea sandstone, (b) Danian chalk from the Kraka oilfield, and (c) Danian chalk from the Dan oilfield. All rocks are saturated with 2 wt% NaCl solutions and were measured by two instruments: (1) Oxford Maran DRX-HF vertical bore permanent magnet at 1H frequency of 8.5 MHz, and (b) Nalorac 2.4 T horizontal bore superconducting magnet equipped with a Tecmag console at 1H frequency of 98.8 MHz
Evaporation of Water in a Glass Bead Pack
No full textEvaporation of deionized water (blue) in a glass bead pack (gray, bead diameter = 2 mm) at 21°C and 45% relative humidity. Six segmented images at different time points are selected from a series of 3D images acquired by a custom-built X-ray tomography system.</p
Effects of Tyrode's solution osmolarities and milk on bull sperm storage above zero temperatures
No full textBackground: Control of the medium osmolarity and temperature during long or short time sperm manipulation is essential.Objective: The objectives of the present study were to find the effects of different osmolarities of modified Tyrode's solution and milk on the bull sperm during incubation at above zero temperatures.Materials and Methods: Semen samples were collected twice from five Najdi bull. Centrifuged and most parts of seminal plasma were removed. First experiment: The concentrated semen were splited into nine aliquots to incubate in three different osmolarities (200, 300 and 400 mOsm) at three temperatures (5, 25 and 39°C) for 15 and 60 min of incubation. Second experiment: The semen samples were splited, mixed with the same volume of whole cow milk (5 and 25°C) and milk with 7% glycerol (5°C) and incubated for 15 and 60 min. Results: Sperm motility severely affected (p0.05) by increasing temperature during 1 h of incubation. Milk can protect the sperm viability and motility at cool conditions and there is no beneficial effect of glycerol in combination of milk on sperm incubation at above zero temperatures (p<0.05).Conclusion: Iso- and hyper-osmotic solutions protect bull sperm motility and viability at 25 and 39°C, while milk can be used for protecting sperm at 5°C
Effects of Tyrode's solution osmolarities and milk on bull sperm storage above zero temperatures
No full textBackground: Control of the medium osmolarity and temperature during
long or short time sperm manipulation is essential. Objective: The
objectives of the present study were to find the effects of different
osmolarities of modified Tyrode's solution and milk on the bull sperm
during incubation at above zero temperatures. Materials and Methods:
Semen samples were collected twice from five Najdi bull. Centrifuged
and most parts of seminal plasma were removed. First experiment: The
concentrated semen were splited into nine aliquots to incubate in three
different osmolarities (200, 300 and 400 mOsm) at three temperatures
(5, 25 and 39°C) for 15 and 60 min of incubation. Second
experiment: The semen samples were splited, mixed with the same volume
of whole cow milk (5 and 25°C) and milk with 7% glycerol
(5°C) and incubated for 15 and 60 min. Results: Sperm motility
severely affected (p<0.05) by incubation at low ionic tension (200
mOsm/l) especially at low temperature (5°C). The impact of low
osmolarity on sperm viability can reduce by increasing the incubation
temperature to 39°C. The decreased sperm motility, which was
induced by lowering osmolarity, was not improved (p>0.05) by
increasing temperature during 1 h of incubation. Milk can protect the
sperm viability and motility at cool conditions and there is no
beneficial effect of glycerol in combination of milk on sperm
incubation at above zero temperatures (p<0.05). Conclusion: Iso- and
hyper-osmotic solutions protect bull sperm motility and viability at 25
and 39°C, while milk can be used for protecting sperm at 5°C
Impact resistance of concrete using dovetailed fibres and type 2 synthetic fibres
No full textThis paper investigates the relative performance of new dovetailed (DT) cross section fibres with regard to impact resistance and energy absorption of concrete. The DT fibres are compared to concrete made with other commercially available Type 2 (T2) fibre types and plain concrete. The two diameters of the prototype DT fibre as tested; are currently in their development stage and not commercially available at present.
The test examines two diameters of polypropylene DT fibres and a single size Type 2 structural synthetic fibre, to evaluate the relative mix performance. The parameters of the test are: compressive strength, flexural strength, energy absorption (toughness) measured with load and deflection and time dependant absorbed energy using a drop hammer impact test. Dosage rates for all samples were 6kg/m³ and 30kg/m³. The compressive strength test was carried out using plain concrete.
Impact tests showed that the peak force required to induce a crack in the beams, was generally increased with the addition of fibres to the concrete mix. Total energy absorption was also increased utilising a higher fibre dosage; with a 30 kg/m³ dosage displaying the greatest increase. The post crack toughness indices of the concrete utilising DT fibres at a 30 kg/m³ fibre dosage produced superior values to the other concrete types tested.
These findings suggest that the addition of DT fibres at the correct dosage will increase the impact resistance and energy absorption of concrete
Role of LIGHT in the pathogenesis of joint destruction in rheumatoid arthritis
No full textTo characterise the role of substitutes for receptor-activator nuclear factor kappa-B ligand (RANKL) in rheumatoid arthritis (RA) joint destruction.Synovial fluid (SF) macrophages isolated from the knee joint of RA patients were incubated with 25 ng/mL macrophage-colony stimulating factor (M-CSF) and 50 ng/mL LIGHT (lymphotoxin-like, exhibits inducible expression and competes with herpes simplex virus glycoprotein D for herpes virus entry mediator, a receptor expressed by T lymphocytes) in the presence and absence of 25 ng/mL RANKL and 100 ng/mL osteoprotegerin (OPG) on glass coverslips and dentine slices. Osteoclastogenesis was assessed by the formation of multinucleated cells (MNCs) expressing tartrate-resistant acid phosphatase (TRAP) on coverslips and the extent of lacunar resorption pit formation on dentine slices. The concentration of LIGHT in RA and osteoarthritis (OA) synovial fluid was measured by an enzyme-linked immunosorbent assay (ELISA) and the expression of LIGHT in RA and OA synovium was determined by immunohistochemistry using an indirect immunoperoxidase technique.In cultures of RA SF macrophages treated with LIGHT and M-CSF, there was significant formation of TRAP + MNCs on coverslips and extensive lacunar resorption pit formation on dentine slices. SF-macrophage-osteoclast differentiation was not inhibited by the addition of OPG, a decoy receptor for RANKL. Resorption pits were smaller and less confluent than in RANKL-treated cultures but the overall percentage area of the dentine slice resorbed was comparable in LIGHT- and RANKL-treated cultures. LIGHT significantly stimulated RANKL-induced lacunar resorption compared with RA SF macrophages treated with either RANKL or LIGHT alone. LIGHT was strongly expressed by synovial lining cells, subintimal macrophages and endothelial cells in RA synovium and the concentration of LIGHT was much higher in RA compared with OA SF.LIGHT is highly expressed in RA synovium and SF, stimulates RANKL-independent/dependent osteoclastogenesis from SF macrophages and may contribute to marginal erosion formation
Exponential Capillary Pressure Functions in Sedimentary Rocks
No full textThe Brooks-Corey power-law capillary pressure model is commonly imposed on core analysis data without verifying the validity of its underlying assumptions. The Brooks-Corey model, originally developed to model the pressure head during the drainage of soil, is only valid at low wetting phase saturations. However, such models are often applied in petroleum production simulations and may lead to erroneous recovery factors when the saturation range of interest is far from the end points. We demonstrate that exponential models work much better for capillary pressure compared to the Brooks-Corey model over a wide saturation range. Mercury injection porosimetry, petrographic image analysis, and magnetic resonance studies suggest that the pore and throat size distribution in many rocks are log-normally distributed. This fact was previously employed to calculate the capillary pressure function as a function of saturation for pore size distributions described by atruncated log-normal distribution. Employing a Taylor series expansion, we simplify the random fractal capillary pressure model of Hunt to Pc = exp(a − bS), where S is the wetting phase saturation, and a and b characteristic of the porous medium. An extensive dataset of seventeen centrifuge capillary pressure measurements were used in this research to demonstrate the merit of the new method. For both sandstones and carbonates, the logarithm of capillary pressure showed a linear relationship with saturation as observed by magnetic resonance imaging centrifuge capillary pressure measurements over a wide saturation range. This work demonstrates that: (a) in semi-log plots of capillary pressure as a function of saturation, capillary pressurewill vary linearly over a wide saturation range, (b) such a plot as described in (a) will show the uni-or bimodal pore size distribution of the rock, (c) the exponential capillary pressure function simplifies analytical modelsthat use the capillary pressure function, for example oil recovery models for fractured reservoirs
A recombinase polymerase amplification assay for rapid detection of Crimean-Congo Haemorrhagic fever Virus infection.
No full textBackgroundCrimean-Congo Haemorrhagic fever Virus (CCHFV) is a rapidly emerging vector-borne pathogen and the cause of a virulent haemorrhagic fever affecting large parts of Europe, Africa, the Middle East and Asia.Methodology/principle findingsAn isothermal recombinase polymerase amplification (RPA) assay was successfully developed for molecular detection of CCHFV. The assay showed rapid (under 10 minutes) detection of viral extracts/synthetic virus RNA of all 7 S-segment clades of CCHFV, with high target specificity. The assay was shown to tolerate the presence of inhibitors in crude preparations of mock field samples, indicating that this assay may be suitable for use in the field with minimal sample preparation. The CCHFV RPA was successfully used to screen and detect CCHFV positives from a panel of clinical samples from Tajikistan.Conclusions/significanceThe assay is a rapid, isothermal, simple-to-perform molecular diagnostic, which can be performed on a light, portable real-time detection device. It is ideally placed therefore for use as a field-diagnostic or in-low resource laboratories, for monitoring of CCHF outbreaks at the point-of-need, such as in remote rural regions in affected countries
Exponential Capillary Pressure Functions in Sedimentary Rocks
No full textThe Brooks-Corey power-law capillary pressure model is commonly imposed on core analysis data without verifying the validity of its underlying assumptions. The Brooks-Corey model, originally developed to model the pressure head during the drainage of soil, is only valid at low wetting phase saturations. However, such models are often applied in petroleum production simulations and may lead to erroneous recovery factors when the saturation range of interest is far from the end points. We demonstrate that exponential models work much better for capillary pressure compared to the Brooks-Corey model over a wide saturation range. Mercury injection porosimetry, petrographic image analysis, and magnetic resonance studies suggest that the pore and throat size distribution in many rocks are log-normally distributed. This fact was previously employed to calculate the capillary pressure function as a function of saturation for pore size distributions described by atruncated log-normal distribution. Employing a Taylor series expansion, we simplify the random fractal capillary pressure model of Hunt to Pc = exp(a − bS), where S is the wetting phase saturation, and a and b characteristic of the porous medium. An extensive dataset of seventeen centrifuge capillary pressure measurements were used in this research to demonstrate the merit of the new method. For both sandstones and carbonates, the logarithm of capillary pressure showed a linear relationship with saturation as observed by magnetic resonance imaging centrifuge capillary pressure measurements over a wide saturation range. This work demonstrates that: (a) in semi-log plots of capillary pressure as a function of saturation, capillary pressurewill vary linearly over a wide saturation range, (b) such a plot as described in (a) will show the uni-or bimodal pore size distribution of the rock, (c) the exponential capillary pressure function simplifies analytical modelsthat use the capillary pressure function, for example oil recovery models for fractured reservoirs
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