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Various Angles (various + angle)
Selected AbstractsBumble bee preference for flowers arranged on a horizontal plane versus inclined planesFUNCTIONAL ECOLOGY, Issue 6 2008T. T. Makino Summary 1Determining factors affecting pollinator visitation is the key to understanding the reproductive success of animal-pollinated plants. The inclination of the ground where plants grow, which has been little studied, could be one such factor. There may be differences in foraging performance when visiting flowers on horizontal planes compared with flowers on inclines planes. And if this is the case, pollinators may have a preference for horizontal or inclined planes. To test these possibilities, a series of laboratory experiments with bumble bees and arrays of artificial flowers were conducted. 2In the first experiment, bees were presented with a pair of floral arrays, one on a horizontal plane and one sloping. The bees preferred visiting flowers on the horizontal array. 3In the second experiment, bees were allowed to forage on a flower array tilted at various angles ranging from 0° (horizontal) to 90° (vertical). It was found that their foraging performance decreased with increasing angles, showing a 9·1% reduction from 0° to 90° arrays. This reduction was caused by an increased travel time between flowers, when moving upslope or downslope. 4These results suggest that plants growing on steep slopes may be less preferred by pollinators. Future studies are needed to clarify how slopes affect pollinator behaviour in field conditions and the ecological influences on plant reproduction. [source] Detection of a low-relief 18th-century British siege trench using LiDAR vegetation penetration capabilities at Fort Beauséjour,Fort Cumberland National Historic Site, CanadaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2009Koreen Millard Airborne Light Detection and Ranging (LiDAR), a remote sensing data collection technique, has many applications in the field of archaeology, including aiding in the planning of field campaigns, mapping features beneath forest canopy, and providing an overview of broad, continuous features that may be indistinguishable on the ground. LiDAR was used to create a high-resolution digital elevation model (DEM) in a heavily vegetated area at Fort Beauséjour,Fort Cumberland National Historic Site, Canada. Previously undiscovered archaeological features were mapped that were related to the siege of the fort in 1755. Features that could not be distinguished on the ground or through aerial photography were identified by overlaying hillshades of the DEM created with artificial illumination from various angles. LiDAR provides accurate digital topographic models with the additional benefit of mapping vertical surfaces in accurate detail below the forest canopy. © 2009 Wiley Periodicals, Inc. [source] Computation of heat transfer enhancement in a plate-fin heat exchanger with triangular inserts and delta wing vortex generatorINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 9 2010Gulshan Sachdeva Abstract Longitudinal vortices disrupt the growth of the thermal boundary layer, thereby the vortex generators producing the longitudinal vortices are well known for the enhancement of heat transfer in compact heat exchangers. The present investigation determines the heat transfer characteristics with secondary flow analysis in plate fin triangular ducts with delta wing vortex generators. This geometrical configuration is investigated for various angles of attack of the wing i.e. 15°, 20°, 26° and 37° and Reynolds numbers 100 and 200. The constant wall temperature boundary condition is used. The solution of the complete Navier Stokes equation and the energy equation is carried out using the staggered grid arrangement. The performance of the combination of triangular secondary fins and delta wing with stamping on slant surfaces has also been studied. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effect of Implant Angulation upon Retention of Overdenture AttachmentsJOURNAL OF PROSTHODONTICS, Issue 1 2005MSEd, MSciDent, Michael P. Gulizio DMD Introduction: Overdentures supported and retained by endosteal implants depend upon mechanical components to provide retention. Ball attachments are frequently described because of simplicity and low cost, but retentive capacity of these components may be altered by a lack of implant parallelism. Purpose: The aim of this in vitro study was to investigate the retention of gold and titanium overdenture attachments when placed on ball abutments positioned off-axis. Methods and Materials: Four ball abutments were hand-tightened onto ITI dental implants and placed in an aluminum fixture that allowed positioning of the implants at 0°, 10°, 20°, and 30° from a vertical reference axis. Gold and titanium matrices were then coupled to the ball abutments at various angles and then subjected to pull tests at a rate of 2 mm/second; the peak loads of release (maximum dislodging forces) were recorded and subjected to statistical analyses. A balanced and randomized factorial experimental design testing procedure was implemented. Results: Statistically significant differences in retention of gold matrices were noted when ball abutments were positioned at 20° and 30°, but not at 0° and 10°. Statistically significant differences were noted among the titanium matrices employed for the testing procedure, as well as for the 4 ball abutments tested. Angle was not a factor affecting retention for titanium matrices. Conclusions: (1) The gold matrices employed for the testing procedures exhibited consistent values in retention compared to titanium matrices, which exhibited large variability in retention. (2) Angle had an effect upon the retention of gold matrices, but not for titanium matrices. [source] Phase Biaxility in Smectic-A Side-Chain Liquid Crystalline ElastomersMACROMOLECULAR RAPID COMMUNICATIONS, Issue 8 2009Rebekka Storz Abstract 2H NMR investigations on the biaxial phase behavior of smectic-A liquid crystalline side-chain elastomers are presented. Biaxiality parameters were determined by measuring the quadrupolar splitting of two spin probes, namely benzene-d6 and hexamethylbenzene-d18, at various angles between the principal director and the external magnetic field: while for a uniaxial sample the angular dependence can be described by the second Legendre polynomial, an additional asymmetric term needs to be included to fit the data of the two investigated biaxial systems. Two elastomers synthesized from mesogens that differ in the molecular geometry in order to study the molecular origin of biaxiality were compared. Biaxiality is observed for both elastomers when approaching the glass transition, suggesting that the network dynamics dominate the formation of the biaxial phase. [source] Nutritional Effect of Dialysis TherapyARTIFICIAL ORGANS, Issue 3 2003Tsutomu Sanaka Abstract: The prognosis of patients with end-stage renal disease has been improved by the recent remarkable advances in medical and engineering technology. However, there are still many unsolved problems in the clinical field. One of the problems is an intractable malnutrition characterized by clinical manifestations including hypoproteinemia and decrease in muscular volume, which is associated with deterioration in the quality of the patient's life. Malnutrition in hemodialysis patients involves abnormal energy metabolism and aberrant amino acid metabolism. In the most malnourished patients, immunodefense mechanisms and homeostasis are disrupted, greatly influencing the prognosis. Moreover, when the performance of dialyzer used is too high, the dialysis treatment might remove a necessary nutrient for the patient. There is also a possibility that the protein catabolism is accelerated when the biocompatibility is inferior. On the other hand, in malnutri-tion, the circulating level of insulin-like growth factor-1 (IGF-1) falls while the level of insulin-like growth factor binding protein-1 (IGFBP-1) is remarkably increased. It has been recognized that IGF-1 and IGFBP-1 are indicators reflecting the initiation of a malnutritional state in patients with chronic renal failure, although there are many indicators such as albumin, prealbumin, and anthropometric measurement for nutritional assessment. We have suggested that r-hGH and IGF-1 improve the malnutritional state by alleviating hypoproteinemia and abnormality of serum amino acid profile in uremic patients on hemodialysis. The serum IGF-1/IGFBP-1 ratio is useful not only as a nutritional parameter but also as a predicting index of responsiveness to r-hGH. It is necessary to examine the problem from various angles to improve malnutrition in the dialysis patient, while considering the above mentioned. [source] | ||||||||||