Impact of biochars on swell-shrinkage behavior, mechanical strength, and surface cracking of clayey soil

2014 ◽  
Vol 177 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Yutong Zong ◽  
Danping Chen ◽  
Shenggao Lu
Keyword(s):  
Mechanical Strength ◽  
Clayey Soil ◽  
Surface Cracking ◽  
Shrinkage Behavior

scholarly journals Effect of Alkali Pollutant in Influencing Crack Propagation in Soils

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Junhong Yuan ◽  
Jingbo Cui ◽  
Jianmei Chang ◽  
Guanhong Zhang ◽  
Mingxi Liu
Keyword(s):  
Sodium Carbonate ◽  
Water Loss ◽  
Clayey Soil ◽  
Loss Ratio ◽  
Climate Conditions ◽  
Surface Cracking ◽  
The Third ◽  
Carbonate Concentration ◽  
Shrinkage Cracks ◽  
Cracking Process

Shrinkage, deformation, and cracking will occur under extreme climate conditions such as drought, due to the accumulation of salt inside the soil during the evaporation of water on the surface of the soil. In this study, the image processing method was used to quantitatively analyze the dehydration cracking process of clay polluted by alkaline pollutant sodium carbonate on the basis of experiments. The mechanism of the effect of sodium carbonate concentration on the shrinkage cracks of clay was discussed through the analysis and comparison of different concentrations of sodium carbonate samples. The results showed that the water loss and shrinkage cracks of alkaline contaminant clay were developed in different stages. Firstly, first-level cracks developed diagonally or parallel to the edge of the container, and then second-level cracks developed along the main cracks with an angle of close to 90°. Most of the third-level or higher-level cracks were approximately perpendicular to the second-level cracks or the edge of the container and developed in parallel. In the cracking stage, the water loss ratio of the sample had a good positive correlation with the surface crack ratio. The slope of the fitted curve increased with the increase of the sodium carbonate concentration. With the increase of sodium carbonate concentration, the water loss ratio and the width of first-level cracks of clayey soil decreased, and the total length and the number of cracks increased, while the surface cracking ratio increased first and then decreased.

scholarly journals THE MECHANICAL STRENGTH AND DRYING SHRINKAGE BEHAVIOR OF HIGH PERFORMANCE CONCRETE WITH BLENDED MINERAL ADMIXTURE

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Cheah Chee Ban ◽  
Lim Jay Sern ◽  
Nurshafarina Jasme
Keyword(s):  
Mechanical Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Drying Shrinkage ◽  
Mineral Admixture ◽  
Replacement Level ◽  
Strength Performance ◽  
Ternary Blended Concrete ◽  
Shrinkage Behavior

With the fast in population development, there are a higher demand in housing and infrastructure such as high-rise buildings and long-span bridges. Therefore, high performance concrete (HPC) is used massively due to its technical and economical advantages to fulfil people demands towards the concrete usage. Optimum mineral blended admixture replacement ratio with the addition of superplasticizer are the main component which contributed to the formation of HPC in terms of high workability, high strength and high durability. Hence, the optimal cement to blended mineral admixture ratio with the optimum addition of PCE type superplasticizer to achieve the targeted mechanical strength performance of G60 and reduce the drying shrinkage behavior which will results in crack of the ternary blended concrete is highlighted in this report. The influence of the addition of two mineral blended admixture, ground granulated blast furnace slag (GGBS) and pulverized fly ash (PFA) with the ordinary Portland cement (OPC) in different ratio on engineering performance and its drying shrinkage behavior in the age of 7 days, 28 days and 90 days based on different mineral blended admixture replacement level in 50%, 60%, 70% and 80% which GGBS to PFA ratio are controlled in 4:1 and the water to cement ratio was kept in 0.35 is studied. There are two types of PCE type superplasticizer (SP) was added to enhance the workability of the fresh concrete and act as slump retainer. Ternary blended concrete results in low early age (7 days) strength but the performance at later age (28 days and beyond) was encouraging. Results revealed that 80% replacement level have the remarkable result in terms of mechanical strength and drying shrinkage behavior. The study showed that, presence of mineral additives with superplasticizer will produce a similar or enhance the concrete strength properties with the inclusion of GGBS and PFA at the ratio of 4:1 up to 80% as cement replacement. 

FORMULATION AND DEVELOPMENT OF FAST DISSOLVING TABLET OF METOCLOPRAMIDE: AN ANTI-EMETIC DRUG

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya
Keyword(s):  
Mechanical Strength ◽  
Standard Procedure ◽  
Flow Property ◽  
Storage Conditions ◽  
Angle Of Repose ◽  
Dissolution Time ◽  
Disintegration Time ◽  
Powder Blend ◽  
Standard Curve ◽  
The Stability

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet

Plasma Enhanced Chemical Vapor Deposition of Porous Organosilicate Glass ILD Films With k ≤ 2.4.

2003 ◽  
Vol 766 ◽  
Author(s):  
Raymond N. Vrtis ◽  
Mark L. O'Neill ◽  
Jean L. Vincent ◽  
Aaron S. Lukas ◽  
Brian K. Peterson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Chemical Vapor Deposition ◽  
Mechanical Strength ◽  
Thermal Annealing ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organosilicate Glass

AbstractWe report on our work to develop a process for depositing nanoporous organosilicate (OSG) films via plasma enhanced chemical vapor deposition (PECVD). This approach entails codepositing an OSG material with a plasma polymerizable hydrocarbon, followed by thermal annealing of the material to remove the porogen, leaving an OSG matrix with nano-sized voids. The dielectric constant of the final film is controlled by varying the ratio of porogen precursor to OSG precursor in the delivery gas. Because of the need to maintain the mechanical strength of the final material, diethoxymethylsilane (DEMS) is utilized as the OSG precursor. Utilizing this route we are able to deposit films with a dielectric constant of 2.55 to 2.20 and hardness of 0.7 to 0.3 GPa, respectively.

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