Aim: An attempt is made to provide better understanding of the compatibility aspect of excipients with different properties of active pharmaceutical ingredient (API) using various rheological, thermal and morphological studies conducted on binary mixtures of Dibasic Calcium Phosphate anhydrous (DCP-A) and Dibasic Calcium Phosphate dihydrate (DCP-D) forms with cohesive API’s (Acetaminophen and Aspirin).
Method: Binary mixtures of DCP’s were prepared by addition of 0% w/w to 50% w/w of the API in each powder blend. Powder rheological analysis were conducted using FT4 powder rheometer, rotational shear cell and empirical approaches such as angle of repose (AOR), Hausner ratio (HR) and Carr’s index (CI). Thermal analysis was conducted using differential scanning calorimetry (DSC) and thermal effusivity. Morphological studies were conducted using Scanning Electron Microscopy (SEM) to determine the fundamental differences between powder materials.
Result/Conclusions: Powder rheometer showed distinctive understanding in the flowability behavior of binary mixtures with addition of increasing proportion of API’s than empirical approaches. Thermal approaches revealed the potential interaction of water of crystallization DCP-D while such interaction was absent in DCP-A. Binary mixtures prepared using DCP-D were better flowable while blends containing DCP-A were better in stability (physical), compressibility and permeability. This study allows the scientist to understand the powder packing of different blends with their flowability and compressibility parameter and helps selection of appropriate form of hydrate for relevant API. 相似文献
The present work deals with the investigation of a robust analytical scheme to assess the size‐independent fracture energy of concrete. The study involves the numerical modelling of three‐point bend (TPB) concrete beams that are geometrically similar, having constant length to depth ratio with varying range of notch to depth (a/W) ratios. The unique nonlinear behaviour of concrete 1material is incorporated through fracture energy‐based strain‐softening model in the finite‐element numerical simulation. The International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM) fracture energy values are evaluated through numerical simulation of several set of experimentally observed load‐load line displacement response. The RILEM fracture energy values associated with geometrically similar beams have been utilised to develop a methodology for assessment of the size‐independent fracture energy of concrete. The numerically predicted and experimentally evaluated size‐independent fracture energy using the RILEM fracture energy values are found to be in close agreement. 相似文献
Hindu philosophy views the cosmos to be holonomic and self-similar in nature. According to ancient architectural tradition, Hindu temples are symbols of models of the cosmos and their form represents the cosmos symbolically.The procedures and methods used in the construction of Hindu temples bear a striking resemblance to the procedures of computer graphics, including discretization, fractalization and extensive use of recursive procedures, including self-similar iteration. The instructions given in ancient Vastu shastras (texts on architecture) work like general programmes to generate various types of temples.The paper is an attempt to draw attention to the similarities between the procedures and resulting forms in computer graphics and Hindu temple architecture and to explain the relationship that exists between the form of the temple and the concepts of Hindu philosophy. It is proposed that Hindu temples may be viewed as threedimensional fractal models and that the use of fractal geometry procedures has a special symbolic meaning in the generation of the forms of Hindu temples. 相似文献
Recently, measurement-based studies of software systems have proliferated, reflecting an increasingly empirical focus on system availability, reliability, aging, and fault tolerance. However, it is a nontrivial, error-prone, arduous, and time-consuming task even for experienced system administrators, and statistical analysts to know what a reasonable set of steps should include to model, and successfully predict performance variables, or system failures of a complex software system. Reported results are fragmented, and focus on applying statistical regression techniques to monitored numerical system data. In this paper, we propose a best practice guide for building empirical models based on our experience with forecasting Apache web server performance variables, and forecasting call availability of a real-world telecommunication system. To substantiate the presented guide, and to demonstrate our approach in a step by step manner, we model, and predict the response time, and the amount of free physical memory of an Apache web server system, as well as the call availability of an industrial telecommunication system. Additionally, we present concrete results for a) variable selection where we cross benchmark three procedures, b) empirical model building where we cross benchmark four techniques, and c) sensitivity analysis. This best practice guide intends to assist in configuring modeling approaches systematically for best estimation, and prediction results. 相似文献