Visualization of a pharmaceutical unit operation: wet granulation

Recent developments in the field of process engineering and manufacturing sciences enable a new level of process understanding. However, extracting this understanding from increasing amounts of information is challenging. The aim of this study was to create a process vector from a model process describing all relevant information and, by that means, create a tool for combining and visualizing this information. Physical (impeller torque and temperature) and chemical (near-infrared spectroscopy) information from a small-scale high-shear granulation was used in the process vector. The vectors created were visualized by two different methods: principal component analysis (PCA) and the self-organizing map (SOM). None of the individual measurement techniques were able to describe the state of the process alone, although they provided important information about the process. By combining the data and visualizing it, an overview could be achieved. The SOM approach had two advantages over the PCA: it presented the results in terms of the original variables and enabled the analysis of nonlinear responses. However, both visualization methods could be used to describe the progress of the process and to increase the level of process understanding.     

Light transmission model for determination of the refractive index of solid particles in suspensions: an immersion study

We report on a model to determine the light transmission of solid particles in immersion liquids. Using the model, optical and physical properties of suspensions such as the refractive index of the particles can be retrieved. The model can also be used in the case of colored suspensions, where the detection of only the maximum transmission would give an inaccurate refractive index for a particle. The validity of the method was tested with CaF(2) particles. Potential applications include scientific studies of the optical properties of micro- and nanoparticles or microorganisms in a liquid matrix. The model is also useful in industry where monitoring of suspensions and colloids is an issue.     

Three-dimensional modeling of removal torque and fracture progression around implants

In the present study, a model for simulations of removal torque experiments was developed using finite element method. The interfacial retention and fracturing of the surrounding material caused by the surface features during torque was analyzed. It was hypothesized that the progression of removal torque and the phases identified in the torque response plot represents sequential fractures at the interface. The 3-dimensional finite element model fairly accurately predicts the torque required to break the fixation of acid-etched implants, and also provides insight to how sequential fractures progress downwards along the implant side.     

Low Temperature Characteristics of the Metal–Superconductor NIS Tunneling Thermometer

We discuss the temperature dependence of a common low temperature local thermometer, a tunnel junction between a superconductor and a normal metal (NIS junction). Towards the lowest temperatures its characteristics tend to saturate, which is usually attributed to selfheating effects. In this technical note, we reanalyze this saturation and show that the temperature independent subgap current of the junction alone explains in some cases the low temperature behavior quantitatively.

     

Ion-implanted capacitively coupled silicon strip detectors with integrated polysilicon bias resistors processed on a 100 mm wafer

Double-sided silicon strip detectors with integrated coupling capacitors and polysilicon resistors have been processed on a 100 mm wafer. A detector with an active area of 19 × 19 mm² was connected to LSI readout electronics and tested. The strip pitch of the detector is 25 μm on the p-side and 50 μm on the n-side. The readout pitch is 50 μm on both sides. The number of readout strips is 774 and the total number of strips is 1161. On the p-side a signal-to-noise of 35 has been measured using a ⁹⁰Sr β-source. The n-side has been studied using a laser.     

Correction to: Embrittlement Analysis of Σ5[210]/(-1-20) FeAl Grain Boundary in Presence of Defects: An Ab Initio Study

Metallurgical and Materials Transactions A -     

Dual boundary element analysis of closed cracks

A two-dimensional boundary element method for analysis of closed or partially closed cracks under normal and frictional forces is developed. The single domain dual formulation is used. As a contact problem is non-linear due to the friction phenomena at the crack interface and also because of the boundary conditions which may change during the loading, it is formulated in an incremental and iterative fashion. The stress intensity factors are calculated with the J-integral method. Also crack growth is considered. Several benchmark cases have been analysed to verify the results given by the method. The stress intensity factors and crack paths calculated are similar to those given in the literature. © 1997 John Wiley & Sons, Ltd.     

Computerized product process: Measurement and continuous improvement

Product development has until recently been considered pure art instead of being a controllable process. However, the current competitive environment has forced companies to take a closer look in the way new products are being developed. A key element in this assessment is the development of a set of metrics, which describe the whole product development process. This article explores the data-based opportunities for continuous improvement in the product development process emerging alongside the increasing utilization of networked Information Technology (IT) applications. Based on data from information systems in the case-study companies, three different product process visualizations are presented. Each visualization is discussed both from the viewpoint of its explanatory power as well as its limitations.The results of the case-studies clearly indicate that the computerization of the engineering and design processes is generating new ways of measuring, understanding and improving product development. The appropriate measures combined with open communication and a learning environment can be used to create a cycle of continually improving the product development process.