THE AGGREGATE CRUSHING TEST FOR EVALUATING THE MECHANICAL STRENGTH OF COARSE AGGREGATES.

1945 ◽  
Vol 24 (6) ◽  
pp. 125-133 ◽  
Author(s):  
A H D MARKWICK ◽  
F A SHERGOLD
Keyword(s):  
Mechanical Strength ◽  
Coarse Aggregates ◽  
Aggregate Crushing

scholarly journals Influência da Mistura de Agregados Graúdos, Resíduo de Corte de Mármore e Granito e Metacaulim e Aditivos no Desempenho Mecânico do Concreto

2018 ◽  
Vol 12 (12) ◽  
pp. 2
Author(s):  
Diógenes Magri Da Silva
Keyword(s):  
Mechanical Strength ◽  
Mechanical Performance ◽  
Fine Aggregate ◽  
Compression Tests ◽  
Coarse Aggregates ◽  
Super Plasticizer

A evolução dos estudos com relação às propriedades do concreto permitiu que os materiais fossem dosados de forma racionalizada, incluída a incorporação de resíduos provenientes do corte de mármores e granitos em sua produção, bem como foram desenvolvidos produtos específicos para melhorar seu desempenho. Neste trabalho produziu-se um concreto com intuito de estudar as propostas para melhorar o desempenho mecânico. Foi avaliada a influência da mistura de dois tipos de agregados graúdos de mesma origem mineralógica, a substituição de agregado miúdo por Resíduo de Corte de Mármore e Granito (RCMG) e a adição de Metaculim, fibras e aditivos visando elevar a resistência mecânica com relação ao traço de referência. Para tanto, foram realizados ensaios de resistência à tração e à compressão aos sete dias. Com os resultados obtidos foi possível perceber que a utilização de Metacaulim associada a um aditivo superplastificante apresentou o melhor desempenho, aumentando em 50% a resistência à compressão e não afetando a resistência à tração.Palavras-chave: Concreto. Desempenho Mecânico. Resíduo de Corte de Mármore e Granito. Aditivos.AbstractThe evolution of studies about properties regarding the concrete proprieties allowed that the materials were measured in a streamlined way, including the incorporation of waste originating from marble and granite cut in its production, as well as specific products were developed to improve its performance. In this work a concrete of reference was produced with the goal to study theproposals to improve its mechanical performance. It was evaluated the influence of a mixture of two types of coarse aggregates from the same mineralogical origin, the replacement of fine aggregate by Marble and Granite Cut Waste (MGCW) and addition of Metakaolin , fibers and additives in order to increasethe mechanical strength comparing to the concrete of reference. Therefore, tensile and compression tests were performed at seven days. With the results obtained it was possible to realize that the use of Metakaolin associated with super plasticizer additive exhibited the best performance, rising 50% the resistance to compression and not affecting the tensile resistance.Keywords: Concrete. Mechanical Performance. Marble and Granite Cut Waste. Additives.

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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