Conjoint analysis to measure the perceived quality in volume rendering

Visualization algorithms can have a large number of parameters, making the space of possible rendering results rather high-dimensional. Only a systematic analysis of the perceived quality can truly reveal the optimal setting for each such parameter. However, an exhaustive search in which all possible parameter permutations are presented to each user within a study group would be infeasible to conduct. Additional complications may result from possible parameter co-dependencies. Here, we will introduce an efficient user study design and analysis strategy that is geared to cope with this problem. The user feedback is fast and easy to obtain and does not require exhaustive parameter testing. To enable such a framework we have modified a preference measuring methodology, conjoint analysis, that originated in psychology and is now also widely used in market research. We demonstrate our framework by a study that measures the perceived quality in volume rendering within the context of large parameter spaces.     

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.     

Infrared heated μ-blistering,a new fabrication technology for HARMST

Polymeric replication technologies such as injection moulding or hot-embossing have gained wide acceptance in the microtechnological community, microthermoforming of thin polymer foils, also called μ-blistering, still remains relatively unknown. Although the general potentials of the µ-blistering have already been pointed out, little work has been carried out addressing its capability for high aspect ratio microstructuring. In the scope of this work we therefore demonstrate the feasibility of μ-blistering to obtain aspect ratios for free standing structures of up to 7 within a process cycle time of <4 min. The presented processing technology uniquely combines manufacturing of macro-, micro- and even nanoscopic feature sizes in a single process.     

New Bioactive Oxylipins Formed by Non-Enzymatic Free-Radical-Catalyzed Pathways: the Phytoprostanes

In animals and plants, fatty acids with at least three double bonds can be oxidized to prostaglandin-like compounds via enzymatic and non-enzymatic pathways. The most common fatty acid precursor in mammals is arachidonic acid (C20:4) (AA) which can be converted through the cyclooxygenase pathway to a series of prostaglandins (PG). Non-enzymatic cyclization of arachidonate yields a series of isoprostanes (IsoP) which comprises all PG (minor compounds) as well as PG isomers that cannot be formed enzymatically. In contrast, in plants, α-linolenic acid (C18:3) (ALA) is the most common substrate for the allene oxide synthase pathway leading to the jasmonate (JA) family of lipid mediators. Non-enzymatic oxidation of linolenate leads to a series of C18-IsoPs termed dinor IsoP or phytoprostanes (PP). PP structurally resemble JA but cannot be formed enzymatically. We will give an overview of the biological activity of the different classes of PP and also discuss their analytical applications and the strategies developed so far for the total synthesis of PP, depending on the synthetic approaches according to the targets and which key steps serve to access the natural products.     

Mechanical performance of hybrid rice straw/sea weed polypropylene composites

Rice straw (Rs)/polypropylene (PP) composites were prepared in the different ratio of 5 : 95, 10 : 90, 15 : 85, 20 : 80, 25 : 75, and 30 : 70 (Rs wt % : PP wt %) by an injection molding process. This work investigated the tensile strength (TS), bending strength (BS), and impact strength (IS) of the composites. From the results, it is observed that Rs20 : PP80 mixture composite showed better performance with mechanical properties (TS = 26.2 MPa, BS = 58 N/mm², and IS = 1.7 KJ/mm²) among the composites prepared. Two hybrid composites were also fabricated using 20% Rs, 10% seaweed with 70% PP and 20% Rs, 30% seaweed with 70% PP. In between the two hybrid composites, superior mechanical behavior showed by the hybrid composite in ratio of Rs20 : Sw10 : PP70 with enhanced results such as TS = 28 MPa, BS = 68 N/mm², and IS = 2.5 KJ/mm². Water uptake, simulating weathering, and soil degradation test of different composites were also performed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Voltage sags in industrial systems

The cause of voltage sags in industrial plants, their impacts on equipment operation, and possible solutions are described. The definition proposed focuses on system faults as the major cause of voltage sags. The sensitivity of different types of industrial equipment, including adjustable speed drive controls, programmable logic controllers, and motor contactors is analyzed. Available methods of power conditioning for this sensitive equipment are also described     

Induction of fibrinogen expression in the lung epithelium during Pneumocystis carinii pneumonia

Pneumocystis carinii is an important pulmonary pathogen responsible for morbidity and mortality in patients with AIDS. The acute-phase response (APR), the primary mechanism used by the body to restore homeostasis following infection, is characterized by increased levels of circulating fibrinogen (FBG). Although the liver is the primary site of increased FBG synthesis during the APR, we unexpectedly discovered that FBG is synthesized and secreted by lung alveolar epithelial cells in vitro during an inflammatory stimulus. Therefore, we sought to determine whether lung epithelial cells produce FBG in vivo using animal models of P. carinii pneumonia (PCP). Inflammation was noted by an influx of macrophages to P. carinii-infected alveoli. Northern hybridization revealed that gamma-FBG mRNA increased two- to fivefold in P. carinii-infected lung tissue, while RNA in situ hybridization demonstrated increased levels of gamma-FBG mRNA in the lung epithelium. Immunoelectron microscopy detected lung epithelial cell-specific production of FBG, suggesting induction of a localized inflammatory response resembling the APR. A systemic APR was confirmed by a two- to fivefold upregulation of the levels of hepatic gamma-FBG mRNA in animals with PCP, resulting in a corresponding increase in levels of FBG in plasma. Furthermore, immunoelectron microscopy revealed the presence of FBG at the junction of cell membranes of trophic forms of P. carinii organisms aggregated along the alveolar epithelium. These results implicate FBG in the pathogenesis of PCP in a manner similar to that of the adhesive glycoproteins fibronectin and vitronectin, which are known to participate in intra-alveolar aggregation of organisms and adherence of P. carinii to the lung epithelium.     

Bracing of patients after fusion for degenerative problems of the lumbar spine--yes or no?

The majority of spine fusions currently performed are for degenerative conditions. Controversy exists regarding whether to routinely brace patients during the postoperative period. The benefits of a rigid orthosis have yet to be documented in a scientific study, and the cost of a custom-molded orthosis can be quite high. An extensive literature search reveals few articles dealing with the subject, and none with an adequate study design to convincingly support or refute the use of external braces. In addition to the questions of whether an external brace is effective, the mechanism of action also remains unclear. It has been difficult to document mechanical effectiveness, so perhaps the effect is psychologic. In addition, it is possible that some, not all, fusion patients may benefit from a brace--yet our ability to select such a patient is poor. As a result, we have solicited the views of two experienced surgeons on the topic. Dr. Connolly argues that an external orthosis is advisable in many cases; Dr. Grob feels that the rigidity of internal fixation should be adequate to obviate the need for external bracing.