scholarly journals Study on Dispersion of Cement Grout in Sand considering Filtration Effect through the EDTA Titration Test

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Daimao Li ◽  
Xuhui Li ◽  
Yu Hu ◽  
Sizhan Zhang ◽  
Chao Mei ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Radial Direction ◽  
Theoretical Study ◽  
Cement Content ◽  
Soil Strength ◽  
Sand Layer ◽  
Laboratory Studies ◽  
Edta Titration ◽  
Filtration Effect ◽  
Different Levels

When grouting in a sand layer, the filtration of the layer on cement particles is an important aspect affecting the grout dispersion. However, few laboratory studies have been conducted to investigate the distribution of cement particles along the direction of dispersion. In this study, a group of laboratory tests were conducted by grouting in a sand layer under different levels of pressure. The distributions of cement particles in sand after curing were then measured using the EDTA titration test. The results show that, due to the filtration effect, the cement content along the radial direction of dispersion decreases nonlinearly in a reversed S shape. The filtration effect becomes more obvious when grouting with a higher grout concentration. With the decrease in grout concentration, the filtration effect becomes weak and cement particles could disperse farther in the sand layer, but the cement content in a farther location becomes lower and the improvement of the soil strength is limited. In the end, the measured results were compared with the calculated results according to an existing theoretical study and the trend reasonably matches with each other.

Results of the experimental bits bench test, equipped with the compound built-up layers

2020 ◽  
pp. 52-56
Author(s):  
V.N. Gadalov ◽  
V. M. Brodsky ◽  
E.A. Filatov ◽  
A.V. Filonovic
Keyword(s):  
Tungsten Carbide ◽  
Laboratory Tests ◽  
Bench Test ◽  
Laboratory Studies ◽  
Induction Method ◽  
Gas Flame ◽  
Flame Method ◽  
Drilling Bit ◽  
Pilot Tests

The article shows the results of performance laboratory studies of compound built-up layers, as well as benches of the pilot tests of the drilling bit rolling cutters, equipped on the bit gage surface of the compound built-up layer; the hardening layers were located along the gage teeth contour. The cast tungsten carbide building-up welding on experimental bits was carried out using a gas-flame method. The induction method of building-up welding was implemented on the rolling cutters of the serial bits. The article shows the results of comparative indicators of serial and experimental bits when their processing on the bench. It was found that experimental bits were more efficient than the serial ones. The estimation of the performance laboratory tests results was confirmed by tests on the bench under pilot conditions of the rolling cutter bits drilling, equipped on the bit gage surface by the compound built-up layer.

scholarly journals Laboratory studies of homing orientation in the eastern red-spotted newt, Notophthalmus viridescens

1987 ◽  
Vol 131 (1) ◽  
pp. 215-229 ◽  
Author(s):  
J. B. Phillips
Keyword(s):  
Water Temperature ◽  
Laboratory Tests ◽  
Notophthalmus Viridescens ◽  
Magnetic Orientation ◽  
Laboratory Studies ◽  
Navigational System ◽  
South Axis ◽  
Magnetic North ◽  
Migratory Period ◽  
East West

The orientation behaviour of adult male eastern red-spotted newts (Notophthalmus viridescens) was studied in laboratory tests. Newts were collected from ponds located 10–30 km from the laboratory, and housed in water-filled, all-glass aquaria located in a greenhouse or outdoors adjacent to the laboratory building. The aquaria were aligned on the magnetic north-south axis. Newts were tested in a dry, enclosed arena in four magnetic fields: the ambient magnetic field (magnetic north at North) and three altered fields (magnetic north rotated to East, West or South). Newts tested during January-March exhibited weak bimodal magnetic orientation along the axis of the holding tank. However, during the spring migratory period (April until early May), the bimodal response shifted to coincide with the direction of the pond from which the newts had been collected. Much stronger unimodal orientation was elicited by elevating the water temperature to 33–34 degrees C immediately prior to testing. If newts were held in a training tank with an artificial shoreline at one end and exposed to elevation of water temperature after several days of stable water temperatures, they exhibited unimodal shoreward orientation and did not show the seasonal switch to homing behaviour observed in the earlier tests. If, however, the elevation of water temperature followed a period of fluctuating water temperature (over a 20 degrees C range), the newts exhibited strong unimodal orientation in the direction of the pond from which they had been collected. These results suggest that newts possess a navigational system that enables them to home from distances in excess of 20 km. Moreover, these experiments provide the first opportunity to examine the sensory basis of navigational ability in any animal under controlled laboratory conditions.

LABORATORY TESTS OF DISINFECTANT «MONOCHLORIDE (IODINE CHLORIDE) 2%»

2018 ◽  
Vol 1 (4) ◽  
pp. 27-33
Author(s):  
N. I. Popov ◽  
◽  
A. V. Suvorov ◽  
S. M. Lobanov ◽  
S. A. Michko ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Laboratory Tests ◽  
Consumption Rate ◽  
Laboratory Work ◽  
Laboratory Studies ◽  
E Coli ◽  
Iodine Chloride ◽  
Test Objects ◽  
Test Cultures

The article describes the results of laboratory tests of the effectiveness of the disinfectant Monochloride (Iodine chloride) 2%. Laboratory studies were carried out on test objects and test surfaces contaminated with test cultures of microorganisms, which included museum cultures of E. coli (E. coli 1257), S. aureus 209-P, mycobacteria (pcs. B5), and spores (B. cereus pieces. 96). Disinfection of test objects was carried out by the method of irrigation at a consumption rate of 0,25...0,3 l/ m2 with disinfection of smooth surfaces and 0,5 l/m2, with disinfection of rough surfaces. The treatment was performed twice with an interval of 60 minutes. Our work established that the Monochloride (Iodine chloride) 2% has a high disinfectant activity against Escherichia coli, Staphylococcus aureus, mycobacteria and spores. On the basis of the laboratory work, this tool can be recommended for production tests at veterinary surveillance facilities.

Evaluation of Hydrogen Cracking Susceptibility in X120 Girth Welds

2004 ◽  
Author(s):  
M. L. Macia ◽  
D. P. Fairchild ◽  
J. Y. Koo ◽  
N. V. Bangaru
Keyword(s):  
Laboratory Tests ◽  
High Strength ◽  
Test Method ◽  
Laboratory Studies ◽  
Long Distance ◽  
Hydrogen Cracking ◽  
Girth Welding ◽  
Groove Test ◽  
Girth Welds ◽  
The Cost

To reduce the cost of long distance gas transmission, high strength pipeline steels are being developed. Implementation of high strength pipeline materials requires the avoidance of hydrogen cracking during field girth welding. A study of hydrogen cracking in X120 girth welds has been conducted. Cracking resistance of both the weld metal and heat affected zone (HAZ) were investigated. The laboratory tests included the controlled thermal severity (CTS) test, the WIC test and the Y-groove test. In addition, multi-pass plate welds and full pipe welds were completed and examined for the presence of hydrogen cracks. The suitability of each test method for predicting cracking in X120 girth welds is determined. The morphology of hydrogen cracks in X120 girth welds is described, and the conditions necessary to prevent hydrogen cracking are identified. Following the laboratory studies, construction of X120 pipelines without cracking was demonstrated through a 1.6 km field trial.

scholarly journals Laboratory studies of the flow rates of debris-laden ice

2003 ◽  
Vol 37 ◽  
pp. 108-112 ◽  
Author(s):  
Tim H. Jacka ◽  
Shavawn Donoghue ◽  
Jun Li ◽  
William F. Budd ◽  
Ross M. Anderson
Keyword(s):  
Laboratory Tests ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Laboratory Studies ◽  
Polar Ice ◽  
Flow Rates ◽  
Basal Ice ◽  
Ice Flows ◽  
Polar Ice Sheets ◽  
Deformation Tests

AbstractIce-sheet basal ice is warmer than that above because of the heat from the Earth’s interior. The stresses acting on the basal ice are greatest. In addition, the basal ice often contains debris consisting of silt and small stones picked up from the rock over which the ice flows. Because the base is the warmest part of an ice sheet and the stress there is greatest, flow rates in the basal ice are large and often contribute most of the ice movement. It is therefore important, for accurate modelling of the ice sheets, to know whether the debris within the basal ice enhances or retards the flow of the ice. In this paper, we describe laboratory deformation tests in uniaxial compression and in simple shear, on sand-laden ice. We find no significant dependence of flow rate on sand content (up to 15% volume) in the stress range 0.13–0.5 MPa and temperature range –0.02 to –18.0°C. Further work needs to include laboratory tests on debris-laden ice extracted from the polar ice sheets. This work is underway.

RELATIONSHIPS BETWEEN DIFFERENT-ORDER POLARIZABILITIES AND GROUND STATE DIPOLE MOMENT

2013 ◽  
Vol 12 (01) ◽  
pp. 1250099 ◽  
Author(s):  
K. HATUA ◽  
PRASANTA K. NANDI
Keyword(s):  
Dipole Moment ◽  
Ground State ◽  
Rational Design ◽  
Theoretical Study ◽  
Basis Sets ◽  
Ground State Dipole Moment ◽  
Donor Acceptor ◽  
Equilibrium Structures ◽  
Different Order ◽  
Different Levels

A number of charge transferring molecules with varying electron donor, acceptor and π-conjugative paths have been considered for the theoretical study of their NLO properties in terms of the linear polarizability and the ground state dipole moment. The equilibrium structures are calculated at the HF, MP2 and B3LYP levels, respectively. The longitudinal components of NLO coefficients are calculated by using HF, MP2, B3LYP, BHHLYP, CAM-B3LYP, and wB97XD methods for 6-31+G(p,d) and 6-311++G(p,d) basis sets. The hyperpolarizabilities obtained at different levels of calculation showed a fairly consistent trend. The relationships between hyperpolarizabilities, polarizability and ground state dipole moment have been proposed by considering only the two-level term in the standard sum-over-state (SOS) expressions and the generalized Thomas–Kuhn (TK) sum rule. The ab initio calculated first- and second-hyperpolarizabilities fairly correlate with the reduced 2-level contributions relating to the linear polarizability and ground state dipole moment. For a given length of conjugation the stronger enhancement of cubic polarizability arises from the increase of quadratic polarizability for comparable values of linear polarizability and dipole moment. The idea developed in the present work can be used to make a rational design of potential NLO-phores.

Laboratory Studies on the Food of Some Coccinellids (Coleoptera) Found in Ontario Peach Orchards

1957 ◽  
Vol 89 (12) ◽  
pp. 572-579 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Biological Control ◽  
Food Habits ◽  
Laboratory Tests ◽  
Economic Importance ◽  
Laboratory Studies ◽  
Present Account ◽  
Stethorus Punctillum

Food habits and occurrence of the commoner species of coccinellids in peach orchards of the Niagara Peninsula, Ontario, are being investigated in connection with a study of the effects of pesticides on biological control agencies. Results of a study of Stethorus punctillum Weise have already been published (Putman, 1955). The present account deals with laboratory tests of feeding, mostly during June and July from 1952 to 1955, with prey of special economic importance in peach orchards.

Effect of Humidity on the Properties of Cement Mortars with a Crystalline Additive

2018 ◽  
Vol 276 ◽  
pp. 53-59 ◽  
Author(s):  
Nikol Žižková ◽  
Lenka Nevřivová ◽  
Matěj Lédl
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Secondary Crystallization ◽  
Polypropylene Fibres ◽  
Cement Mortars ◽  
Different Levels

The paper focuses on examining the properties of mortars in which secondary crystallization (crystalline additive) was used. Laboratory tests have found that the effect of secondary crystallization is influenced by conditions in which specimens have been stored during the first 28 days. The investigation focused on the physical-mechanical properties and microstructure of mortar specimens containing a crystalline additive and polypropylene fibres stored at different levels of humidity for 28 days. The influence of crystalline additive on strength was studied as well and the results show that crystalline additives improves the 28-day strength of the mortars.

scholarly journals Availability of laboratory diagnosis of gonorrhoea and its meaning in case reporting in Shandong province, China

2020 ◽  
Author(s):  
Xinlong Chen ◽  
Yanling Gan ◽  
dianchang liu
Keyword(s):  
Laboratory Tests ◽  
Descriptive Analysis ◽  
Laboratory Diagnosis ◽  
Shandong Province ◽  
Clinical Services ◽  
Chi Square ◽  
Transmitted Infection ◽  
Sexually Transmitted ◽  
Significant Difference ◽  
Different Levels

Abstract Background The aim of this study is to understand the availability of laboratory diagnosis of gonorrhoea in Shandong province and its meaning in case reporting. Methods Two surveys were conducted among hospitals providing clinical services for sexually transmitted infection(STI) in Shandong Province in 2012 and 2018. The availability of laboratory tests for Neisseria gonorrhoeae (NG) and distribution of reported gonorrhea cases were compared among different hospitals provided clinical services for STI in Shandong province. Descriptive analysis and Chi-square were used for statistical analysis. Results Smear, culture and PCR tests for NG were used among 301(74.69%), 123(30.52%), 43(10.67%) hospitals in 2012 and 356(74.48%), 176(36.82%) and 73(15.27%) hospitals in 2018, respectively. Significant differences were observed in the availability of smear among hospitals at different levels (X2 = 12.159, p = 0.000) and with different affiliations(X2 = 4.551, p = 0.033) in 2018. Significant differences were observed in the availability of culture and PCR tests among hospitals at different levels both in 2012 (X2 = 34.532, p = 0.000; X2 = 7.380, p = 0.007) and 2018 (X2 = 49.820, p = 0.000; X2 = 21.658, p = 0.000). The availability of culture and PCR tests for NG among hospitals in 2018 was higher than that in 2012 (X2 = 3.870, p = 0.049; X2 = 4.050, p = 0.044). More hospitals reported gonorrhea cases in 2018 than in 2012 (X2 = 6.768, p = 0.009). A significant difference was observed in distribution of case reporting among hospitals at different levels in 2018 (X2 = 6.975, p = 0.008) and among different types of hospitals both in 2012 (X2 = 52.362, p = 0.000) and 2018 (X2 = 74.478, p = 0.000). Conclusion Poor availability of NG laboratory tests affects case reporting and is a crucial reason leading to high sex ratio and underreporting of gonorrhea cases in Shandong province. Trial registration Not applicable

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