scholarly journals Derivation of a New Equation to Obtain the Permeability Coefficient of Clayey Soils

2011 ◽  
Vol 5 (1) ◽  
pp. 20
Author(s):  
Maysm Th. Al-Hadidy
Keyword(s):  
Permeability Coefficient ◽  
Clayey Soil ◽  
Point Of View ◽  
Clayey Soils ◽  
Coefficient Of Permeability ◽  
Long Time ◽  
Consolidation Rate ◽  
Degree Of Consolidation ◽  
New Equation ◽  
Short Time

The main objective of this research is to find the coefficient of permeability (k) of the soil and especially clayey soil by finding the degree of consolidation (rate of consolidation). New modify procedure is proposed by using the odometer (consolidation) device. The ordinary conventional permeability test usually takes a long time by preparing and by testing and this could cause some problems especially if there is a need to do a large number of this test and there were a limited number of technicians and/or apparatus. From this point of view the importance of this research is clear, since the modified procedure will require a time of 25 minute only. Derivation made to produce an equation which could be used to fined the permeability if the proposed procedure fallowed to find the permeability of soils and this done by specification the degree of consolidation at any loading stage. The results of permeability found by the proposed procedure and by ordinary test (directly by falling head method, and indirectly by accelerated consolidation method using the oedometer device). After that these results were found by proposed procedure compared with that results which found by ordinary test. it has been found that this equation give a very good results with (95.83) % accuracy and degree of correlation of (0.9988) comparing with ordinary methods and beside that it takes a very short time.

scholarly journals Measurement of hydraulic conductivity under horizontal paths in granular soils

Respuestas ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 92-101
Author(s):  
Maria Fernanda García ◽  
Camilo Andres Aldana ◽  
Allex Fabrizio López ◽  
Juan Carlos Ruge C. ◽  
Eliana Martinez Rojas
Keyword(s):  
Hydraulic Conductivity ◽  
Permeability Coefficient ◽  
Point Of View ◽  
Granular Soils ◽  
Physical Point ◽  
Soil Layers ◽  
Coefficient Of Permeability ◽  
Geotechnical Structures ◽  
The Difference ◽  
Constant Head

In geotechnical structures, the permeability-dependent stability analysis is generally evaluated under vertical trajectories, because most permeameters are configured so that the water passes through the porous medium in this way. However, it is clear from the physical point of view that water can flow along different paths, including preferential ways that can include horizontal trajectories, parallel to the deposit of the stratum. The foregoing implies that both the vertical and horizontal component of the hydraulic conductivity or permeability coefficient must be estimated for a given stratum. The current research aims to explore possibilities for measuring the coefficient of permeability in horizontal trajectories, on granular soils, under a constant condition of relative density. For this purpose, a special chamber attached to a constant head permeameter was designed and constructed, which allows to measure the permeability in conditions of horizontal flow parallel to the soil layers. The proposed camera also admits the estimation of the permeability coefficient by combining stratifications of different granular soils, where the trajectories are not perfectly horizontal, but have diagonal paths. The results are compared with data obtained by conventional vertical flow permeameters, in order to check the difference in the measurements considering both situations in the samples. As a conclusion, it is important to report that there is evidently a difference in the permeability coefficients measured under different trajectories,

Short-Time Tests for Long-Time Endurance

1923 ◽  
Vol 128 (4) ◽  
pp. 264-264
Author(s):  
J. W. Harsch
Keyword(s):  
Long Time ◽  
Short Time

Effect of Vial shaking on Loading Time of Epirubicin into Drug-Eluting Bead

2015 ◽  
Vol 5 (3) ◽  
Author(s):  
Kenji Ikeda ◽  
Yusuke Kawamura ◽  
Masahiro Kobayashi ◽  
Taito Fukushima ◽  
Yushi Sorin ◽  
...  
Keyword(s):  
Antitumor Agent ◽  
Loading Rates ◽  
Vortex Mixer ◽  
Long Time ◽  
Group A ◽  
Drug Eluting ◽  
Large Hepatocellular Carcinoma ◽  
Group B ◽  
Time Required ◽  
Short Time

Background: Although DC Bead has been useful in treatment of multiple and large hepatocellular carcinoma, loading time of doxorubicin into the DC Bead takes a long time of 30-120 minutes. Epirubicin is also used as an antitumor agent together with DC Bead, but its loading efficiency was not sufficiently elucidated. Methods: To shorten loading time of epirubicin into DC Bead (100-300µm, 300-500µm, 500-700µm), we examined the following three methods after mixing the drug: (a) let stand in room temperature, (b) agitated for 30 seconds with Vortex mixer, and (c) sonicated for 30 seconds with ultrasonic cleaner. After loading of epirubicin by each method, supernatant concentration for epirubicin was assayed at 5, 10, 30, 60, and 120 minutes. Results: Epirubicin loading rates for small bead (100-300µm) at 5 minutes were 82.9 % in group a, 93.8% in group b, and 79.9 % in group c. Similarly, medium bead (300-500µm), 40.1% in group a, 65.7% in group b and 45.5% in group c, respectively. In large-sized bead (500-700µm), loaded rates of epirubicin were 38.8% in group a, 59.0% in group b and 48.0% in group c. Agitation of mixture of epirubicin and DC Bead with Vortex mixer significantly shortened the loading time, but sonication did not affect the time required. Microscopic examination did not lead to any morphological change of microspheres in all the methods. Conclusions: Short time of agitation with Vortex mixer reduced the necessary time for loading of epirubicin in every standard of DC Bead.

Robust Test Method of TSOP PEMs for Space Application

2019 ◽  
Author(s):  
Yasunobu Iwai ◽  
Koichi Shinozaki ◽  
Daiki Tanaka
Keyword(s):  
Evaluation Method ◽  
Low Cost ◽  
Reliability Evaluation ◽  
Test Method ◽  
Thermal Shock Test ◽  
Space Application ◽  
Space Applications ◽  
Limit Test ◽  
Long Time ◽  
Short Time

Abstract Compared with space parts, consumer parts are highly functional, low cost, compact and lightweight. Therefore, their increased usage in space applications is expected. Prior testing and evaluation on space applicability are necessary because consumer parts do not have quality guarantees for space application [1]. However, in the conventional reliability evaluation method, the test takes a long time, and the problem is that the robustness of the target sample can’t be evaluated in a short time. In this report, we apply to the latest TSOP PEM (Thin Small Outline Package Plastic Encapsulated Microcircuit) an evaluation method that combines preconditioning and HALT (Highly Accelerated Limit Test), which is a test method that causes failures in a short time under very severe environmental conditions. We show that this method can evaluate the robustness of TSOP PEMs including solder connections in a short time. In addition, the validity of this evaluation method for TSOP PEM is shown by comparing with the evaluation results of thermal shock test and life test, which are conventional reliability evaluation methods.

Adjustable wetting of Liquid Flame Spray (LFS) TiO2-nanoparticle coated board: Batch-type versus roll-to-roll stimulation methods

2014 ◽  
Vol 29 (2) ◽  
pp. 271-279 ◽  
Author(s):  
Mikko Tuominen ◽  
Hannu Teisala ◽  
Janne Haapanen ◽  
Mikko Aromaa ◽  
Jyrki M. Mäkelä ◽  
...  
Keyword(s):  
Argon Plasma ◽  
Ultra Violet ◽  
High Volume ◽  
Point Of View ◽  
Flame Spray ◽  
Ambient Conditions ◽  
Batch Type ◽  
Roll To Roll ◽  
Long Time ◽  
Liquid Flame Spray

Abstract Superhydrophobic nanoparticle coating was created on the surface of board using liquid flame spray (LFS). The LFS coating was carried out continuously in ambient conditions without any additional hydrophobization steps. The contact angle of water (CAW) of ZrO2, Al2O3 and TiO2 coating was adjusted reversibly from >150° down to ~10−20° using different stimulation methods. From industrial point of view, the controlled surface wetting has been in focus for a long time because it defines the liquid-solid contact area, and furthermore can enhance the mechanical and chemical bonding on the interface between the liquid and the solid. The used stimulation methods included batch-type methods: artificial daylight illumination and heat treatment and roll-to-roll methods: corona, argon plasma, IR (infra red)- and UV (ultra violet)-treatments. On the contrary to batch-type methods, the adjustment and switching of wetting was done only in seconds or fraction of seconds using roll-to-roll stimulation methods. This is significant in the converting processes of board since they are usually continuous, high volume operations. In addition, the creation of microfluidic patterns on the surface of TiO2 coated board using simple photomasking and surface stimulation was demonstrated. This provides new advantages and possibilities, especially in the field of intelligent printing. Limited durability and poor repellency against low surface tension liquids are presently the main limitations of LFS coatings.

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

Alteration of intrapancreatic serotonin, homocysteine, TNF-α, and NGF levels as predisposing factors for diabetes following exposure to 900-MHz waves

2021 ◽  
pp. 074823372110226
Author(s):  
Gholamali Jelodar ◽  
Mansour Azimzadeh ◽  
Fatemeh Radmard ◽  
Narges Darvishhoo
Keyword(s):  
Cell Damage ◽  
Pancreatic Beta Cell ◽  
Predisposing Factors ◽  
Male Rats ◽  
Control Group ◽  
Predisposing Factor ◽  
Time Exposure ◽  
Tnf Α ◽  
Long Time ◽  
Short Time

Exposure to mobile phone radiation causes deleterious health effects on biological systems. The objects of this study were to investigate the effect of 900-MHz radiofrequency waves (RFW) emitted from base transceiver station antenna on intrapancreatic homocysteine (Hcy), tumor necrosis factor-α (TNF-α), and nerve growth factor (NGF) as predisposing factors involved in pancreatic beta cell damage. Thirty male rats (Sprague-Dawley, 200 ± 10 g) were randomly divided into the control (without any exposure) and exposed groups: short time (2 h/day), long time (4 h/day), and exposed to 900-MHz RFW for 30 consecutive days. On the last days of the experiment, animals were killed and pancreas tissue was dissected out for evaluation of serotonin, Hcy, TNF-α, and NGF. There was a significant decrease in the serotonin and NGF levels in the pancreatic tissue of exposed groups compared to the control group ( p < 0.05). Also, the levels of serotonin and NGF in the long-time exposure were significantly lower than the short-time exposure ( p < 0.05). However, levels of Hcy and TNF-α were significantly increased in the pancreas of exposed groups compared to the control groups ( p < 0.05). Exposure to 900-MHz RFW decreased pancreatic NGF and serotonin levels and increased the proinflammatory markers (Hcy and TNF-α), which can be a predisposing factor for type 2 diabetes.

scholarly journals Internal dosimetry in F-18 FDG PET examinations based on long-time-measured organ activities using total-body PET/CT: does it make any difference from a short-time measurement?

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Pengcheng Hu ◽  
Xin Lin ◽  
Weihai Zhuo ◽  
Hui Tan ◽  
Tianwu Xie ◽  
...  
Keyword(s):  
Effective Dose ◽  
Dynamic Model ◽  
Bladder Wall ◽  
Time Measurement ◽  
Post Injection ◽  
Time Activity ◽  
Pet Ct ◽  
Long Time ◽  
Total Body ◽  
Short Time

Abstract Purpose A 2-m axial field-of-view, total-body PET/CT scanner (uEXPLORER) has been recently developed to provide total-body coverage and ultra-high sensitivity, which together, enables opportunities for in vivo time-activity curve (TAC) measurement of all investigated organs simultaneously with high temporal resolution. This study aims at quantifying the cumulated activity and patient dose of 2-[F-18]fluoro-2-deoxy-D-glucose (F-18 FDG ) imaging by using delayed time-activity curves (TACs), measured out to 8-h post-injection, for different organs so that the comparison between quantifying approaches using short-time method (up to 75 min post-injection) or long-time method (up to 8 h post-injection) could be performed. Methods Organ TACs of 10 healthy volunteers were collected using total-body PET/CT in 4 periods after the intravenous injection of F-18 FDG. The 8-h post-injection TACs of 6 source organs were fitted using a spline method (based on Origin (version 8.1)). To compare with cumulated activity estimated from spline-fitted curves, the cumulated activity estimated from multi-exponential curve was also calculated. Exponential curve was fitted with shorter series of data consistent with clinical procedure and previous dosimetry works. An 8-h dynamic bladder wall dose model considering 2 voiding were employed to illustrate the differences in bladder wall dose caused by the different measurement durations. Organ absorbed doses were further estimated using Medical Internal Radiation Dose (MIRD) method and voxel phantoms. Results A short-time measurement could lead to significant bias in estimated cumulated activity for liver compared with long-time-measured spline fitted method, and the differences of cumulated activity were 18.38% on average. For the myocardium, the estimated cumulated activity difference was not statistically significant due to large variation in metabolism among individuals. The average residence time differences of brain, heart, kidney, liver, and lungs were 8.38%, 15.13%, 25.02%, 23.94%, and 16.50% between short-time and long-time methods. Regarding effective dose, the maximum differences of residence time between long-time-measured spline fitted curve and short-time-measured multi-exponential fitted curve was 9.93%. When using spline method, the bladder revealed the most difference in the effective dose among all the investigated organs with a bias up to 21.18%. The bladder wall dose calculated using a long-time dynamic model was 13.79% larger than the two-voiding dynamic model, and at least 50.17% lower than previous studies based on fixed bladder content volume. Conclusions Long-time measurement of multi-organ TACs with high temporal resolution enabled by a total-body PET/CT demonstrated that the clinical procedure with 20 min PET scan at 1 h after injection could be used for retrospective dosimetry analysis in most organs. As the bladder content contributed the most to the effective dose, a long-time dynamic model was recommended for the bladder wall dose estimation.

scholarly journals Inhibition of CCL7 derived from Mo-MDSCs prevents metastatic progression from latency in colorectal cancer

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Xiaoli Ren ◽  
Jianbiao Xiao ◽  
Wanning Zhang ◽  
Feifei Wang ◽  
Yongrong Yan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Suppressor Cells ◽  
Metastatic Progression ◽  
Ht29 Cells ◽  
Metastatic Cells ◽  
Long Time ◽  
Mice Liver ◽  
Short Time ◽  
Related Proteins

AbstractIn colorectal cancer (CRC), overt metastases often appear after years of latency. But the signals that cause micro-metastatic cells to remain indolent, thereby enabling them to survive for extended periods of time, are unclear. Immunofluorescence and co-immunoprecipitation assays were used to explore the co-localization of CCL7 and CCR2. Immunohistochemical (IHC) assays were employed to detect the characters of metastatic HT29 cells in mice liver. Flow cytometry assays were performed to detect the immune cells. Bruberin vivo MS FX Pro Imager was used to observe the liver metastasis of CRC in mice. Quantitative real-time PCR (qRT-PCR) and western blot were employed to detect the expressions of related proteins. Trace RNA sequencing was employed to identify differentially expressed genes in MDSCs from liver micro-M and macro-M of CRC in mice. Here, we firstly constructed the vitro dormant cell models and metastatic dormant animal models of colorectal cancer. Then we found that myeloid-derived suppressor cells (MDSCs) were increased significantly from liver micro-metastases to macro-metastases of CRC in mice. Moreover, monocytic MDSCs (Mo-MDSC) significantly promoted the dormant activation of micro-metastatic cells compared to polymorphonuclear MDSCs (PMN-MDSC). Mechanistically, CCL7 secreted by Mo-MDSCs bound with membrane protein CCR2 of micro-metastatic cells and then stimulated the JAK/STAT3 pathway to activate the dormant cells. Low-dose administration of CCL7 and MDSCs inhibitors in vivo could significantly maintain the CRC metastatic cells dormant status for a long time to reduce metastasis or recurrence after radical operation. Clinically, the level of CCL7 in blood was positively related to the number of Mo-MDSCs in CCR patients, and highly linked with the short-time recurrence and distant metastasis. CCL7 secreted by Mo-MDSCs plays an important role in initiating the outgrowth of metastatic latent CRC cells. Inhibition of CCL7 might provide a potential therapeutic strategy for the prevention of metastasis recurrence.

scholarly journals Expression Level of Mature miR172 in Wild Type and StSUT4-Silenced Plants of Solanum tuberosum Is Sucrose-Dependent

2021 ◽  
Vol 22 (3) ◽  
pp. 1455
Author(s):  
Varsha Garg ◽  
Aleksandra Hackel ◽  
Christina Kühn
Keyword(s):  
Solanum Tuberosum ◽  
Wild Type ◽  
Potato Plants ◽  
Mature Leaves ◽  
In Vitro Plantlets ◽  
Long Time ◽  
Short Time ◽  
Cut Leaves

In potato plants, the phloem-mobile miR172 is involved in the sugar-dependent transmission of flower and tuber inducing signal transduction pathways and a clear link between solute transport and the induction of flowering and tuberization was demonstrated. The sucrose transporter StSUT4 seems to play an important role in the photoperiod-dependent triggering of both developmental processes, flowering and tuberization, and the phenotype of StSUT4-inhibited potato plants is reminiscent to miR172 overexpressing plants. The first aim of this study was the determination of the level of miR172 in sink and source leaves of StSUT4-silenced as well as StSUT4-overexpressing plants in comparison to Solanum tuberosum ssp. Andigena wild type plants. The second aim was to investigate the effect of sugars on the level of miRNA172 in whole cut leaves, as well as in whole in vitro plantlets that were supplemented with exogenous sugars. Experiments clearly show a sucrose-dependent induction of the level of mature miR172 in short time as well as long time experiments. A sucrose-dependent accumulation of miR172 was also measured in mature leaves of StSUT4-silenced plants where sucrose export is delayed and sucrose accumulates at the end of the light period.

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