User Satisfaction with Tablet PC Features

Previous studies of tablet personal computers have concentrated on their use in education and healthcare. The current study focused instead on personal usage, investigating how satisfied users are with their own tablets after having used them in their daily lives. The objective was to identify the major features for tablets and to investigate how form factors affect the preference of functions by performing a comparison of iPad1 and Galaxy Tab. Also, gender and ethnicity were analyzed to determine whether they influence satisfaction with the devices. For e‐mail and web browsing functions, users’ ratings showed more satisfaction with the iPad1 since it has a larger display; for the e‐book reader function, users indicated higher satisfaction with the Galaxy Tab. Male users evaluated their devices by the function itself, whereas female users were mainly concerned with aesthetic aspects. Koreans indicated that they were less satisfied with their tablets than were other ethnic groups.     

Modeling of quantitative relationships between physicochemical properties of active pharmaceutical ingredients and tensile strength of tablets using a boosted tree

Objectives: The aim of this study was to explore the potential of boosted tree (BT) to develop a correlation model between active pharmaceutical ingredient (API) characteristics and a tensile strength (TS) of tablets as critical quality attributes.

Methods: First, we evaluated 81 kinds of API characteristics, such as particle size distribution, bulk density, tapped density, Hausner ratio, moisture content, elastic recovery, molecular weight, and partition coefficient. Next, we prepared tablets containing 50% API, 49% microcrystalline cellulose, and 1% magnesium stearate using direct compression at 6, 8, and 10?kN, and measured TS. Then, we applied BT to our dataset to develop a correlation model. Finally, the constructed BT model was validated using k-fold cross-validation.

Results: Results showed that the BT model achieved high-performance statistics, whereas multiple regression analysis resulted in poor estimations. Sensitivity analysis of the BT model revealed that diameter of powder particles at the 10th percentile of the cumulative percentage size distribution was the most crucial factor for TS. In addition, the influences of moisture content, partition coefficients, and modal diameter were appreciably meaningful factors.

Conclusions: This study demonstrates that BT model could provide comprehensive understanding of the latent structure underlying APIs and TS of tablets.     

Energiedissipation und Energieflüsse während des Tablettiervorganges

The tableting process causes a temperature increase due to dissipation of energy. Therefore, with time the temperature of the tablets and the tablet press increases. Depending on the calculated tablet temperature, this temperature increase is discussed for different compression forces and lubricant concentrations. Two different measurement techniques are presented and compared.     

The use of mobile technology for online shopping and entertainment among older adults in Finland

Older adults are becoming an important market segment for all internet-based services, but few studies to date have considered older adults as online shoppers and users of entertainment media. Utilising the concept of life course, this article investigates the use of mobile technologies for online shopping and entertainment among consumers aged 55 to 74. The data were collected with a web-based survey completed by a panel of respondents representing Finnish television viewers (N = 322). The results reveal that consumers aged 55 to 74 use a smartphone or tablet to purchase products or services online as often as younger consumers. In contrast, listening to internet radio and watching videos or programmes online with a smartphone or tablet are most typical for younger male consumers. The results demonstrate that mobile-based online shopping is best predicted by age, higher education, and household type (children living at home), and use of entertainment media by age and gender.     

Digital geological mapping with tablet PC and PDA: A comparison

Both the hardware and software available for digital geological mapping (DGM) have advanced considerably in recent years. Mobile computers have become cheaper, lighter, faster and more power efficient. Global Positioning Systems (GPS) have become cheaper, smaller and more accurate, and software specifically designed for geological mapping has become available. These advances have now reached a stage where it is effective to replace traditional paper-based mapping techniques with those employing DGM methodologies. This paper attempts to assess and evaluate two currently available DGM systems for geological outcrop mapping: one based on a Personal Digital Assistant (PDA) running ESRI “ArcPad”, and the second based on a Tablet PC running “Map IT” software. Evaluation was based on field assessment during mapping of a well-exposed coastal section of deformed Carboniferous and Permian rocks at N. Tynemouth in NE England. Prior to the field assessment, several key criteria were identified as essential attributes of an effective DGM system. These criteria were used as the basis for the assessment and evaluation process. Our findings suggest that the main concerns presented by sceptics opposed to DGM have largely been resolved.In general, DGM systems using a Tablet PC were found to be most suitable for a wide range of geological data collection tasks, including detailed outcrop mapping. In contrast, systems based on a PDA, due to small screen and limited processing power, were best suited for more basic mapping and simple data collection tasks. In addition, PDA-based systems can be particularly advantageous for mapping projects in remote regions, in situations where there is a limited power supply or where total weight of equipment is an important consideration.     

Prediction of tablet velocity in pan coaters for scale-up

The purpose of this study was to investigate the influence of scale-up on the tablet velocity and surface time of tablets (oblong and biconvex) in the spray zone of different perforated pan coaters. A Bohle Film Coater (BFC) 5 and 10 for the laboratory scale, a BFC 40 for the pilot scale and a BFC 200 for the production scale were used. The pan speeds were scaled-up using the same peripheral speeds. The tablet velocities for 5 peripheral speeds were determined using video imaging of blue tracer tablets. An increasing pan size resulted in a higher tablet velocity and lower surface time in the spray zone for same peripheral speeds. A mathematical model in the literature was proved to predict the tablet velocities in scale-up in the BFCs. The tablet velocities in the pilot or production scale can be predicted based on the measured tablet velocities in the laboratory scale. Furthermore, depending on the pan size, the increase in tablet velocity (R_V-value) can be predicted for the scale-up process using BFCs. The R_V-values were validated for three pan sizes, different pan speeds and three different tablet types. The R_V-value can be used as a correction factor to calculate the scaled-up spray rate based on the same spray rate per spray width ratios.     

Numerical and experimental investigation of capping mechanisms during pharmaceutical tablet compaction

Capping is a common problem in the pharmaceutical tabletting process in which catastrophic failure of the powder compact can occur. It is of great interest to the pharmaceutical industry to understand the fundamental reasons why capping occurs and how it can be avoided. Recently, a combined numerical and experimental study on pharmaceutical powder compaction revealed that cone capping, which is a typical failure mechanism during the production of flat-faced cylindrical tablets using powders of low tensile strength, is due to the formation of a narrow band with localised, intensive shear stresses running from the top edge towards the bottom centre of the tablet [C.Y. Wu, O. Ruddy, A.C. Bentham, B.C. Hancock, S.M. Best, J.A. Elliott, Modelling the mechanical behaviour of pharmaceutical powders during compaction, Powder Technology, 152 (2005)107-117.]. In this paper, the results of further studies are reported in an attempt to explore possible methods to alleviate the propensity for tablets to cap. These methods have been systematically investigated using finite element methods (FEM), and include using lubrication to reduce the die-wall friction, employing different tooling kinematics (speeds and compression profiles), making tablets with different thicknesses, and making convex tablets using punches with curved surfaces. It has been found that none of these methods could avoid the development of intensive shear bands during unloading, which implies that capping cannot necessarily be avoided using these methods. In addition, physical experiments using a compaction simulator have also been carried out, in particular, for making convex tablets with different curvatures. The tablets produced were examined using X-ray microtomography (XMT), from which the failure patterns were identified and found to be in very good agreement with the numerical analysis. The combination of experimental and numerical studies has demonstrated that: (i) capping takes place during the decompression (unloading) phase, and (ii) the intensive shear bands formed during decompression are responsible for the occurrence of capping.     

Press chamber coating as external lubrication for high speed rotary presses: lubricant spray rate optimization

Lubrication of the tooling (punches and dies) is necessary to produce tablets. The most commonly used lubricant is magnesium stearate. Adding and blending magnesium stearate to the tablet mass often has negative effects on the properties of the compressed tablets (e.g., decreasing the tensile strength of the tablet). To avoid these negative effects, external lubrication systems were developed. This study investigated the functionality and the influence of a new press chamber coating system called the PKB II. The major difference between the PKB II and previous systems is its ability to spray a mixture of powdered magnesium stearate and air directly onto the punches and dies which was determined to allow the running of the rotor at higher speeds. The data showed a clear correlation between the spray rate of the lubricant and the concentration of the magnesium stearate per tablet. The PKB II was designed to allow for adjustments, in order to optimize the spray rate, by using the ejection force. The concentration of magnesium stearate was reduced to approximately 0.04% per tablet, using the PKB II. Additionally, the most common negative effects, such as the decrease in tablet tensile strength, were avoided by using this system.