Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Angle

  • abduction angle
  • acute angle
  • advancing contact angle
  • arbitrary angle
  • backbone dihedral angle
  • base angle
  • bend angle
  • bite angle
  • bond angle
  • bragg angle
  • branch angle
  • c bond angle
  • cobb angle
  • cone angle
  • contact angle
  • convergence angle
  • cranial base angle
  • different angle
  • different incidence angle
  • diffraction angle
  • dihedral angle
  • dip angle
  • divergence angle
  • dynamic contact angle
  • elevation angle
  • flexion angle
  • friction angle
  • gonial angle
  • high angle
  • hue angle
  • incidence angle
  • incident angle
  • inclination angle
  • inlet angle
  • interplanar angle
  • joint angle
  • knee angle
  • lordosis angle
  • low angle
  • magic angle
  • mandibular angle
  • oblique angle
  • opening angle
  • orientation angle
  • pennation angle
  • phase angle
  • plane angle
  • position angle
  • pretilt angle
  • receding contact angle
  • right angle
  • rotation angle
  • sample tilt angle
  • scattering angle
  • slope angle
  • small angle
  • solar zenith angle
  • staggering angle
  • tilt angle
  • torsion angle
  • torsional angle
  • twist angle
  • various angle
  • viewing angle
  • water contact angle
  • zenith angle

  • Terms modified by Angle

  • angle analysis
  • angle close
  • angle closure glaucoma
  • angle constraint
  • angle control
  • angle data
  • angle decrease
  • angle dependence
  • angle deposition
  • angle distribution
  • angle effect
  • angle glaucoma
  • angle glaucoma patient
  • angle light scattering
  • angle measurement
  • angle method
  • angle microscopy
  • angle neutron scattering
  • angle spectroscopic ellipsometry
  • angle spinning
  • angle value
  • angle x-ray diffraction
  • angle x-ray scattering

  • Selected Abstracts


    This paper investigates the relationship between the focus and implementation degree of Internet-based information technology (IT) applications and the scope and orientation of process-oriented integration in global supply chains. Using data from 205 plants, which were collected in conjunction with the High Performance Manufacturing project, the degree of supplier and customer integration and its match with the implemented IT instruments supporting interorganizational collaboration are investigated empirically. Different types of integration are differentiated from each other with the help of factor, percentile and cluster analyses. The focus and degree of IT integration is measured for each of the resulting groups and the alignment of both aspects is analyzed with the help of an approach referred to as the angles of integration. With respect to supply chain integration and IT implementation, the analysis of different integration strategies shows that most of the plants do not align their IT implementation with their supply chain strategy. The paper helps companies to evaluate the alignment of their use of IT techniques with their global supply chain management emphases. Additionally, possible reasons for a potential missmatch of functional strategies are discussed giving managers insights for dealing more effectively with a strategic alignment. Furthermore, it refines an existing framework for the comparison of different supply chain integration strategies and applies it with IT. Based on the angles of integration, the match of supply chain integration and IT is investigated by statistical analyses. [source]

    Reinterpretable Imager: Towards Variable Post-Capture Space, Angle and Time Resolution in Photography

    Amit Agrawal
    Abstract We describe a novel multiplexing approach to achieve tradeoffs in space, angle and time resolution in photography. We explore the problem of mapping useful subsets of time-varying 4D lightfields in a single snapshot. Our design is based on using a dynamic mask in the aperture and a static mask close to the sensor. The key idea is to exploit scene-specific redundancy along spatial, angular and temporal dimensions and to provide a programmable or variable resolution tradeoff among these dimensions. This allows a user to reinterpret the single captured photo as either a high spatial resolution image, a refocusable image stack or a video for different parts of the scene in post-processing. A lightfield camera or a video camera forces a-priori choice in space-angle-time resolution. We demonstrate a single prototype which provides flexible post-capture abilities not possible using either a single-shot lightfield camera or a multi-frame video camera. We show several novel results including digital refocusing on objects moving in depth and capturing multiple facial expressions in a single photo. [source]

    Effect of Graft Size, Angle, and Intergraft Distance on Dense Packing in Hair Transplant

    Mohammed Alhaddab MD
    Background. The maximum number of hair grafts that can be safely implanted in 1 cm2 is still debatable. To our knowledge, no previous report has addressed this issue in three dimensions, taking into account the size, the angle of the graft, and the intergraft distance. Objectives. To study the effect of the size and angle of the graft and the intergraft distance on dense packing. Methods. Using a mathematical formula (the maximum number of hair grafts in 1 cm2 = 33 * cosine), the volume of the recipient area and the volume of the hair graft are calculated, assuming that the surface area of the recipient area is 1 cm2, the diameter of the hair graft is 1 mm, and the intergraft distance is 1.5 mm laterally and 1 mm anteriorly and posteriorly. Results. The maximum number of hair grafts that could be implanted in 1 cm2 at a 90 angle in relation to the skin surface is 33 grafts, at a 60 angle is 28 grafts, and at a 30 angle is 16 grafts. Conclusion. The maximum number of hair grafts that can be implanted in any given recipient area depends on the graft size, the angle or direction of these grafts, and the intergraft distance. Where more space is allowed between the grafts, and the more acute the angle, the fewer hair grafts that can be implanted. [source]

    Recipient Area Hair Direction and Angle in Hair Transplanting

    Walter P. Unger MD
    Background. A variety of recommendations for creating "natural" hair directions and angles in hair transplanting have been described. Objective. A method of accomplishing that goal is outlined. Methods. Hair direction and angle are determined by multiple partings of the hair during the course of making recipient sites. Incisions are made to mimic such directions and angles. The direction is usually somewhat coronal and the use of grafts containing more than one follicular unit is particularly advantageous in producing a denser appearance. Results. If the above technique is employed, one does not accelerate the rate at which existing hair in the recipient area is lost and the hair flows in a natural easy to manage fashion. Conclusion. Surgeons should nearly always mimic the scalp hair directions and angles seen in nature. [source]

    An Abnormal Right Ventricular Apical Angle is Indicative of Global Right Ventricular Impairment

    ECHOCARDIOGRAPHY, Issue 5 2006
    Angel López-Candales M.D.
    The presence of right ventricular (RV) dysfunction is an adverse prognostic indicator but current echocardiographic methods have some limitations. RV apical angles in systole and diastole were correlated with known parameters of RV function in patients without pulmonary hypertension (Group 1) and in patients with pulmonary hypertension (Group 2). RV apical angles were significantly smaller in both systole (22 ± 7°) and diastole (33 ± 6°) in Group 1 patients when compared to Group 2 (54 ± 18°, p < 0.0001 and 59 ± 17°, p < 0.0001, respectively). RV apical angles, both in systole and diastole, were strongly correlated with RV end-systolic area (R = 0.89, p < 0.0001) and end-diastolic area (R = 0.81, p < 0.0001), respectively. Similarly, the apical systolic and diastolic angle correlated well with decreased tricuspid annular plane systolic excursion (TAPSE, R =,0.76 and R =,0.73, p < 0.001) as well as with decreased RV fractional area change (R =,0.81 and R =,0.77, p < 0.001). Therefore, we conclude that this new measurement of RV apical angle is simple and useful to quantify RV apical structural and functional abnormalities that are well correlated with global RV impairment in patients with chronic pulmonary hypertension. [source]

    Influence of the Orifice Inlet Angle on the Velocity Profile Across a Flow Convergence Region by Color Doppler In Vitro

    ECHOCARDIOGRAPHY, Issue 5 2000
    Martin Giesler M.D.
    The converging flow field proximal to a leaking valve is determined among other things by the orifice inlet angle formed by the leaflets. Thus, the inlet angle affects the determination of regurgitant flow rate by the flow convergence method. Based on the hypothesis of spheric isovelocity surfaces, others had postulated that a local velocity within the flow convergence should change inversely proportional to changes in the three-dimensional inlet angle. This concept would allow correction of the determination of regurgitant flow for nonplanar orifice inlet angles. We tested this concept in vitro. In a flow model, the flow convergence region proximal to different orifice plates was imaged by color Doppler: funnel-shaped, planar and tip-shaped (inverted funnels) orifice plates, with circular orifices of 2- and 7-mm diameter. Velocity profiles across the flow convergence along the flow centerline were read from the color maps. As predicted, the local velocities were inversely related to the inlet angle, but only at the 2-mm funnel orifices, this effect was inversely proportional to the three-dimensional inlet angle (i.e., in agreement with the mentioned concept). However, for any 7-mm orifice and/or inlet angle of > 180°, the effect of the inlet angle was considerably less than predicted by the aforementioned concept. With increasing orifice diameter and with decreasing distance to the orifice, the effect of the orifice inlet angle was reduced. The effect of the orifice inlet angle on the flow convergence region is modulated by orifice size and the distance to the orifice. Therefore, correction of flow estimates in proportion to the three-dimensional inlet angle will lead to considerable errors in most situations of clinical relevance, namely to massive overcorrection when analyzing velocities located close to wide orifices. [source]

    Developments in research concerning Mesozoic,Tertiary Tethys and neotectonics in the Isparta Angle, SW Turkey

    GEOLOGICAL JOURNAL, Issue 3-4 2003
    Alastair H. F. Robertson
    Abstract The Isparta Angle has played a critical role in the development of concepts concerning the tectonic evolution of the Mesozoic,Tertiary Neotethys in the Eastern Mediterranean region. Following early regional studies, mainly by the Mineral Research and Exploration Institute of Turkey (MTA), during the 1960s and 1970s, a French team mapped the area and confirmed a regional tectonostratigraphy of three great allochthonous systems of mainly Mesozoic,Early Tertiary age, termed the Antalya, Lycian and Hoyran-Bey,ehir-Had,m nappes. During the 1970s and 1980s a British group studied the Neotethyan evolution of what they termed the Antalya Complex, utilizing knowledge of plate tectonic processes. Throughout the 1970s and 1980s MTA systematically remapped the area at 1:25,000 scale. The root zone of the Antalya allochthon was either a southerly Neotethys, within and to the south of the Isparta Angle, or a northerly Neotethys, many hundreds of kilometres to the north. The southerly origin is nowadays favoured but some questions remain. Attention focused in the 1990s until present to the post-collisional, neotectonic evolution of the Isparta Angle and its links with the neighbouring Mediterranean Sea. Here, we trace the development of research and the ongoing debates concerning alternative tectonic concepts used to explain the evolution of the Isparta Angle from Mesozoic to Recent time. We conclude by outlining several tectonic models for the evolution of the Antalya allochthon within a southerly Neotethys that require to be tested by future field studies. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Insights into biaxial extensional tectonics: an examplefrom the Sand,kl, Graben, West Anatolia, Turkey

    GEOLOGICAL JOURNAL, Issue 1 2003
    Mustafa Cihan
    Abstract West Anatolia, together with the Aegean Sea and the easternmost part of Europe, is one of the best examples of continental extensional tectonics. It is a complex area bounded by the Aegean,Cyprus Arc to the south and the North Anatolian Fault Zone (NAFZ) to the north. Within this complex and enigmatic framework, the Sand,kl, Graben (10,km wide, 30,km long) has formed at the eastern continuation of the Western Anatolian extensional province at the north-northwestward edge of the Isparta Angle. Recent studies have suggested that the horst,graben structures in West Anatolia formed in two distinct extensional phases. According to this model the first phase of extension commenced in the Early,Middle Miocene and the last, which is accepted as the onset of neotectonic regime, in Early Pliocene. However, it is controversial whether two-phase extension was separated by a short period of erosion or compression during Late Miocene,Early Pliocene. Both field observations and kinematic analysis imply that the Sand,kl, Graben has existed since the Late Pliocene, with biaxial extension on its margins which does not necessarily indicate rotation of regional stress distribution in time. Although the graben formed later in the neotectonic period, the commencement of extension in the area could be Early Pliocene (c. 5,Ma) following a severe but short time of erosion at the end of Late Miocene. The onset of the extensional regime might be due to the initiation of westward motion of Anatolian Platelet along the NAFZ that could be triggered by the higher rate of subduction at the east Aegean,Cyprus Arc in the south of the Aegean Sea. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Palaeomagnetic evidence for the Gondwanian origin of the Taurides and rotation of the Isparta Angle, southern Turkey

    GEOLOGICAL JOURNAL, Issue 4 2002
    John D. A. Piper
    Abstract The Taurides, the southernmost of the three major tectonic domains that constitute present-day Turkey, were emplaced following consumption of the Tethyan Ocean in Late Mesozoic to mid-Tertiary times. They are generally assigned an origin at the northern perimeter of Gondwana. To refine palaeogeographic control we have investigated the palaeomagnetism of a range of Jurassic rocks. Forty-nine samples of Upper Jurassic limestones preserve a dual polarity remanence (D/I=303/,9°, ,95=6°) interpreted as a primary magnetization acquired close to the equator and rotated during emplacement of the Taurides. Result from mid-Jurassic dolerites confirm a low palaeolatitude for the Tauride Platform during Jurassic times at the Afro,Arabian sector of Gondwana. Approximately 4000,km of Tethyan closure subsequently occurred between Late Jurassic and Eocene times. Although related Upper Jurassic limestones and Liassic redbeds preserve a sporadic record of similar remanence, the dominant signature in these latter rocks is an overprint of probable mid-Miocene age, probably acquired during a single polarity chron and imparted by migration of a fluid front during nappe loading. This is now rotated consistently anticlockwise by c. 30° and conforms to results of previous studies recording bulk Neogene rotation of the Isparta region following Lycian nappe emplacement. The regional distribution of this overprint implies that the Isparta Angle (IA) has been subject to only small additional closure (<10°) since Late Miocene time. A smaller amount (c. 6°) of clockwise rotation within the IA since Early Pliocene times is associated with an ongoing extensional regime and reflects an expanding curvature of the Tauride arc produced by southwestward extrusion of the Anatolian collage as a result of continuing northward motion of Afro,Arabia. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    360 Feedback from Another Angle

    David W. Bracken
    How do you know if a 360 process has been implemented successfully? What are the factors that influence its success? How can those factors be controlled by those responsible for its implementation? Despite its popularity, there has been little effort to build a comprehensive model that addresses these fundamental questions about 360 feedback. In a quest for such a model, we identify a host of key factors organized according to whether they exert their influence proximally or distally. We discuss how each factor contributes to successful implementation. After identifying how design features of a 360 process affect these key factors, we recommend how to enhance the probability of implementing 360 feedback successfully and sustaining the process over time. © 2001 John Wiley & Sons, Inc. [source]

    Effect of Implant Angulation upon Retention of Overdenture Attachments

    MSEd, 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]

    Measurement of Angle and Length of the Eustachian Tube on Computed Tomography Using the Multiplanar Reconstruction Technique

    THE LARYNGOSCOPE, Issue 7 2007
    Kenji Takasaki MD
    Abstract Objective: To compare the anatomic features of the eustachian tube (ET) between children with and without otitis media with effusion (OME) and with adults. Methods: The angle and length of the ET in children with OME (54 ears, OME children) and without OME (50 ears, normal children), as well as those of normal adults (90 ears), were measured on computed tomography using the multiplanar reconstruction technique. Results: The angles of ET in the OME children group, the normal children group, and the normal adult group were 20.4 ± 3.5° and 21.2 ± 4.8°, 19.9 ± 3.4° and 20.0 ± 3.6°, and 27.3 ± 2.7° and 27.3 ± 2.8° on the right and the left sides, respectively. There was no significant difference between the right and the left side in any group (P = .541, P = .952, P = .978). The lengths of ET in the OME children group, the normal children group, and the normal adult group were 37.2 ± 3.0 mm (mean ± SD) and 37.6 ± 3.2 mm, 37.5 ± 3.3 mm and 38.0 ± 3.2 mm, and 42.5 ± 2.8 mm and 42.9 ± 2.9 mm on the right and the left sides, respectively. There was no significant difference between the right and left sides in any group (P = .670, P = .597, and P = .545). Both the angles and lengths were significantly greater in the normal adult group than in either the OME children group or the normal children group (one-way analysis of variance and Fisher's protected least significant difference tests, P < .05), but there was no significant difference in either the angle or length of the ET between the OME and normal children groups (P > .05). In the OME and normal children groups, the angle was observed to constantly increase with age, and the values were found to be within the range of the adult size in all the patients older than 7.5 years and 7.7 years in the OME children group and the normal children group, respectively. As well as the angle, the lengths were observed to constantly increase with age, but the increase appeared to be greater at a younger age (until approximately 3 to 4 years) than at an older age, and the values were found to be within the range of the adult size in all the patients older than 6.8 years and 7.7 years in the OME children group and the normal children group, respectively. Conclusion: The angle and length of the ET are more horizontal and shorter in infants than in adults. However, there is no statistical difference between the angle and length of the ET in infants with and without OME. These results lead us to believe that a short and horizontal ET may not be a main etiologic factor related to high susceptibility to OME in infants and children. [source]

    Dynamics and Rate-Dependence of the Spatial Angle between Ventricular Depolarization and Repolarization Wave Fronts during Exercise ECG

    Tuomas Kenttä M.Sc.
    Background: QRS/T angle and the cosine of the angle between QRS and T-wave vectors (TCRT), measured from standard 12-lead electrocardiogram (ECG), have been used in risk stratification of patients. This study assessed the possible rate dependence of these variables during exercise ECG in healthy subjects. Methods: Forty healthy volunteers, 20 men and 20 women, aged 34.6 ± 3.4, underwent an exercise ECG testing. Twelve-lead ECG was recorded from each test subject and the spatial QRS/T angle and TCRT were automatically analyzed in a beat-to-beat manner with custom-made software. The individual TCRT/RR and QRST/RR patterns were fitted with seven different regression models, including a linear model and six nonlinear models. Results: TCRT and QRS/T angle showed a significant rate dependence, with decreased values at higher heart rates (HR). In individual subjects, the second-degree polynomic model was the best regression model for TCRT/RR and QRST/RR slopes. It provided the best fit for both exercise and recovery. The overall TCRT/RR and QRST/RR slopes were similar between men and women during exercise and recovery. However, women had predominantly higher TCRT and QRS/T values. With respect to time, the dynamics of TCRT differed significantly between men and women; with a steeper exercise slope in women (women, ,0.04/min vs ,0.02/min in men, P < 0.0001). In addition, evident hysteresis was observed in the TCRT/RR slopes; with higher TCRT values during exercise. Conclusions: The individual patterns of TCRT and QRS/T angle are affected by HR and gender. Delayed rate adaptation creates hysteresis in the TCRT/RR slopes. Ann Noninvasive Electrocardiol 2010;15(3):264,275 [source]

    Optimal Moving Angle of Pusher Plate in Occlusive-Type Pulsatile Blood Pump

    ARTIFICIAL ORGANS, Issue 7 2010
    Hyuk Choi
    Abstract Since the occlusive-type pulsatile extracorporeal blood pump (Twin-Pulse Life Support System; Seoul National University, Seoul, Korea) received the CE mark of the European Directives and Korea Food and Drug Administration approval (2004) for short-term applications as an extracorporeal life support system, the pump system has been tested for hemolysis. This pump system was recently upgraded with an ameliorated pusher plate to reduce hemolysis. In this study, numerical analysis and in vitro tests were performed to determine the optimal conditions for increasing the durability of the blood sac and pump output. During the simulation, the minimum sliding interface force (SIF) for the angle of the pusher plate movement (PPM) was calculated (40,70°). In the in vitro durability test, the angle of the PPM was increased gradually from 40 to 70° in 10° increments, and the mean time to failure (MTTF) of the blood sac was calculated. Fifteen tests were conducted for each case: 40, 50, 60, and 70° (n = 15 each). The MTTF of the blood sac was defined as the time when a crack of the blood sac occurred. The longer lifetime of the blood sac at 60° of the PPM (297.0 h) than that at 50° (197.6 h) was attributed to the lower SIF value (,0.13, normalized value) at 60° of the PPM. [source]

    Contact Angle, WAXS, and SAXS Analysis of Poly(,-hydroxybutyrate) and Poly(ethylene glycol) Block Copolymers Obtained via Azotobacter vinelandii UWD

    Kerry J. Townsend
    This study investigated and correlated physical properties and cell interactions of copolymers obtained by a poly(ethylene glycol) (PEG)-modulated fermentation of Azotobacter vinelandii UWD. PEGs with molecular weights of 400 and 3400 Da and di(ethylene glycol) (DEG) were used to modulate the bacterial synthesis of poly(,-hydroxybutyrate) (PHB). The PHB crystallinity was determined by wide-angle X-ray scattering (WAXS). Small-angle X-ray scattering (SAXS) showed that lamellar distances decreased between the PHB and the PHB modulated with PEG or DEG. Furthermore, the contact angle of water on the PHB/PEG polymer surfaces decreased when compared to that of PHB. The significant decrease of the contact angle and corresponding increase in surface tension, as well as significant decrease in cell adhesion, suggest the presence of hydrophilic PEG and DEG within the hydrophobic surface. [source]

    The Algebra of Geometric Impossibility: Descartes and Montucla on the Impossibility of the Duplication of the Cube and the Trisection of the Angle

    CENTAURUS, Issue 1 2010
    Jesper Lützen
    Today we credit Pierre Wantzel with the first proof (1837) of the impossibility of doubling a cube and trisecting an arbitrary angle by ruler and compass. However two centuries earlier Descartes had put forward what probably counts as the first proof of these impossibilities. In this paper I analyze this proof, as well as the later related proof given by Montucla (1754) and the brief version of this proof published by Condorcet (1775). I discuss the many novelties of these early arguments and highlight the problematic points addressed by Gauss (1801) and Wantzel. In particular I show that although Descartes developed many of the algebraic techniques used in later proofs he failed to provide an algebraic impossibility proof and resorted to a geometric argument. Montucla and Condorcet turned this proof into an algebraic one. I situate the analysis of the early proof of the impossibility of the two classical problems in the general context of early modern mathematics where mathematics was primarily viewed as a problem solving activity. Within such a paradigm of mathematics impossibility results arguably do not play the role of proper mathematical results, but rather the role of meta-results limiting the problem solving activity. [source]

    Why Platinum Catalysts Involving Ligands with Large Bite Angle Are so Efficient in the Allylation of Amines: Design of a Highly Active Catalyst and Comprehensive Experimental and DFT Study

    Guilhem Mora
    Abstract The platinum-catalyzed allylation of amines with allyl alcohols was studied experimentally and theoretically. The complexes [Pt(,3 -allyl)(dppe)]OTf (2) and [Pt(,3 -allyl)(DPP-Xantphos)]PF6 (5) were synthesized and structurally characterized, and their reactivity toward amines was explored. The bicyclic aminopropyl complex [Pt(CH2CH2CH2NHBn- , - C,N)(dppe)]OTf (3) was obtained from the reaction of complex 2 with an excess of benzylamine, and this complex was shown to be a deactivated form of catalyst 2. On the other hand, reaction of complex 5 with benzylamine and allyl alcohol led to formation of the 16-VE platinum(0) complex [Pt(,2 -C3H5OH)(DPP-Xantphos)] (7), which was structurally characterized and appears to be a catalytic intermediate. A DFT study showed that the mechanism of the platinum-catalyzed allylation of amines with allyl alcohols differs from the palladium-catalyzed process, since it involves an associative ligand-exchange step involving formation of a tetracoordinate 18-VE complex. This DFT study also revealed that ligands with large bite angles disfavor the formation of platinum hydride complexes and therefore the formation of a bicyclic aminopropyl complex, which is a thermodynamic sink. Finally, a combination of 5 and a proton source was shown to efficiently catalyze the allylation of a broad variety of amines with allyl alcohols under mild conditions. [source]

    Stylet Bend Angles and Tracheal Tube Passage Using a Straight-to-cuff Shape

    Richard M. Levitan MD
    Abstract Objectives Malleable stylets improve maneuverability and control during tube insertion, but after passage through the vocal cords the stiffened tracheal tube may impinge on the tracheal rings, preventing passage. The goal of this study was to assess insertion difficulty with styletted tubes of different bend angles. Methods Tube passage was assessed with four different bend angles (25°, 35°, 45°, and 60°) using straight-to-cuff,shaped tubes. In two separate airway procedure classes, 16 operators in each class (32 total) placed randomly ordered styletted tubes of the different angles into eight cadavers (16 total). Operators subjectively graded the ease of tube passage as no resistance, some resistance, or impossible to advance. Results No resistance was reported in 69.1% (177/256) at 25°, in 63.7% (163/256) at 35°, in 39.4% (101/256) at 45°, and in 8.9% (22/256) at 60°. Tube passage was impossible in 2.3% of insertions (6/256) at 25°, in 3.5% (9/256) at 35°, in 11.3% (29/256) at 45°, and in 53.9% (138/256) at 60°. The odds ratios of impossible tube passage for 35°, 45°, and 60° vs. 25° were 1.52 (95% confidence interval [CI] = 0.55 to 4.16), 5.32 (95% CI = 2.22 to 12.71), and 48.72 (95% CI = 21.35 to 111.03), respectively. Conclusions Bend angles beyond 35° with straight-to-cuff styletted tracheal tubes increase the risk of difficult and impossible tube passage into the trachea. The authors did not compare different stylet stopping points, stylets of different stiffness, or tracheal tubes with different tip designs, all variables that can affect tube passage. [source]

    Old Questions, Fresh Angles: Escalation in Vietnam

    DIPLOMATIC HISTORY, Issue 4 2010
    Mark Atwood Lawrence
    First page of article [source]

    Effect of magnitude and direction of force on laryngeal abduction: Implications for the nerve-muscle pedicle graft technique

    P. CRAMP
    Summary Reasons for performing study: The nerve-muscle pedicle graft technique is a treatment for recurrent laryngeal neuropathy (RLN), but the optimal placement of the pedicles within the cricoarytenoideus dorsalis (CAD) muscle is unknown. Hypothesis: The magnitude and direction of force placed on the muscular process of the left arytenoid cartilage affects the magnitude of laryngeal abduction. Methods: Five larynges were harvested from cadavers. Using increments of 0.98 N, a dead-weight force generator applied a force of 0,14.7 N for 1 min each to the left muscular process at 0, 10, 20, 30, 40, 50, 60 and 70° angles. The rima glottis was photographed digitally 1 min after each force had been applied. Distances between biomarkers (Lines 1,4) and right to left angle quotient (RLQ) were used to assess the degree of left arytenoid abduction. Results: Increasing force from 0,14.7 N progressively and significantly increased the length of all lines and RLQ, indicating abduction. Furthermore, there was a significant interaction between force and angles. Applying forces of 7.84 N or greater (Lines 2,4 and RLQ) or 11.76 N or greater (Line 1) at angles 0, 10, 20 and 30° resulted in significantly greater abduction than applying the same forces at 40, 50, 60 and 70°. Angles of 0,30° correspond with the direction of pull exerted by the lateral compartment of the CAD muscle. Conclusion: In RLN, nerve-muscle pedicle grafts should be placed preferentially in the lateral rather than in the medial compartment of the CAD muscle. Potential relevance: The information presented can be used to assist surgeons in the planning and application of the nerve-muscle pedicle graft procedure. [source]

    Photogeneration of High Pretilt Angles of Nematic Liquid Crystals by Non-Polarized Light Irradiation of Azobenzene-Containing Polymer Films,

    S. Furumi
    Abstract A vertical-alignment (VA) cell of nematic liquid crystals (LCs) was prepared using photoirradiated thin films of a poly(methacrylate) with mesogenic moieties of 4-trifluoromethoxyazobenzene as the side chains. Optical anisotropy was generated by oblique irradiation of the azobenzene-containing polymer films with non-polarized UV light, followed by annealing treatment to enhance the photodichroism, which displayed thermal stability. The combination of oblique exposure to non-polarized UV light and subsequent annealing treatment brought about high pretilt angles of nematic LCs so that a photoaligned VA LC cell was fabricated. The photopatterned LC cell exhibited electro-optical properties with excellent optical quality when a voltage was applied even after heating at 100,°C for several hours. [source]

    Investigation of a New Approach to Measuring Contact Angles for Hydrophilic Impression Materials

    Gerard Kugel DMD
    Purpose: The purpose of this investigation was to examine the initial water contact angles of seven unset impression materials using commercially available equipment, in an effort to determine whether polyether impression materials (Impregum) have lower contact angles and are, therefore, more hydrophilic than VPS impression materials. Materials and Methods: The hydrophilic properties of unset polyether and VPS impression materials were analyzed with respect to their water contact angle measurements using the commercially available Drop Shape Analysis System DSA 10. Twenty-five data points per second were collected via video analysis. There was no delay from start of measurement and data collection. Data was collected for approximately 12 s. Droplet size was determined on the thickness of canula. If the droplets became too small in volume, the water that evaporated during the measurement was large in comparison to the volume of the droplet. Therefore, 5 ,l was chosen as the lowest volume. Five trials were conducted per series for each featured material. Contact angles were calculated using the circle fitting method. Three tests using this technique were designed to control the variables of contact angle measurement with regard to time, the varying amount of fluid in contact with impression material during clinical use, and material thickness. Sample thickness of impression material was controlled by stripping the paste flat on a glass plate using a marking template to ensure a constant film thickness. Tests were conducted in a climatized room at 24°C ± 1°C. Deionized water was used as the fluid. The device was calibrated according to manufacturer's instruction for Young,Laplace fitting prior to the measurements. Results were analyzed using One-Way ANOVA, Tukey test, and t -test, as appropriate. Results: Comparing the fast setting impression materials by One-Way ANOVA and Tukey tests (p < .05) revealed the initial contact angles to range from 66.2 ± 1.5° to 127.5 ± 4.4°, of which the polyether material was the lowest after 45 s (66.2 ± 1.5°), 120 s (70.3 ± 2.8°), and 24 h (80.3 ± 1.0°) after start of the mix. The selected times represent the different stages of unset material, ranging from 45 s as the earliest practical data collection time to 24 h, at which a stone model would be poured. The polyether materials tested exhibited lower contact angles and, thus, significantly higher initial hydrophilicity than all measured VPS materials. Additionally, Impregum impression materials are more hydrophilic in the unset stage than in the set stage. VPS may show a stepwise development of hydrophilicity in the set stage that was not observed in the unset stage. Conclusions: The polyether impression materials tested were significantly more hydrophilic before, during, and after setting than that of VPS impression materials. Regardless of the amount of water in contact with the impression material, the polyether impression materials showed a significantly higher hydrophilicity in the unset stage than the VPS materials. The initial contact angle was not dependent on the thickness of the material. All parameters, including variation of time, volume of water droplet, and thickness of material, resulted in different absolute contact angles, but did not lead to a dramatic change in the ranking of the materials with regard to their hydrophilic behavior. [source]

    Free Rotational Diffusion of Rigid Particles with Arbitrary Surface Topography: A Brownian Dynamics Study Using Eulerian Angles

    Tom Richard Evensen
    Abstract Rotational diffusion of rigid bodies is an important topic that has attracted sustained interest for many decades, but most existing studies are limited to particles with simple symmetries. Here, we present a simple Brownian dynamics algorithm that can be used to study the free rotational diffusion of rigid particles with arbitrary surface topography. The main difference between the new algorithm and previous algorithms is how the numerical values of the mobility tensor are calculated. The only parameters in the numerical algorithm that depend on particle shape are the principal values of the particle rotational mobility tensor. These three scalars contain all information about the surface topography that is relevant for the particle rotational diffusion. Because these principal values only need to be pre-calculated once, the resulting general algorithm is highly efficient. The algorithm is valid for arbitrary mass density distribution throughout the rigid body. In this paper, we use Eulerian angles as the generalized coordinates describing the particle angular orientation. [source]

    Playing the Angles: Russian Diplomacy Before and During the War in Iraq

    MIDDLE EAST POLICY, Issue 3 2003
    Mark N. Katz

    The reliability of crown,root ratio, linear and angular measurements on panoramic radiographs

    Steve Stramotas
    The aim of this study was to evaluate the reliability of crown and root length, crown,root ratio and angular measurements of teeth relative to constructed reference lines and to other teeth in the same region on consecutive (T1 and T2) panoramic radiographs (OPGs). This retrospective study employed 20 cases; ten with five implants in each jaw (age range between 20 and 60 years) and ten with a full permanent dentition (age range between 12 and 16 years). The consecutive pairs of OPGs ranged from 6 months to 3 years apart. Four variables were measured and compared: 1) the crown or coronal segment length and the root or apical segment length; 2) the crown,root ratio; 3) the angulations of teeth and implants relative to specific reference lines in each jaw; 4) the angle between teeth and implants in the same sextant. The results revealed that comparisons of measurements taken of the same structures at T1 and T2, there were no statistically significant differences (p>0.05) between vertical linear measurements. The crown,root ratios and coronal,apical segment ratios too, showed no significant differences (p>0.05). Whereas, angulations of teeth or implants relative to respective reference lines showed significant differences (p=0.001) for some of the teeth. These differences, however, were less than 5°; a clinically acceptable range. Angles measured between teeth or implants in the same sextant showed no significant differences (p>0.05). These results seem to support the hypothesis, therefore, that the linear vertical measurements, ratio calculations and angular measurements can be used to compare crown and root lengths, crown,root ratios and tooth angulations on OPGs taken of the same patient at different times with consistent accuracy. [source]

    Determining Contact Angles of Powders by Liquid Penetration

    Ulrich Teipel
    Abstract The wettability of a powder is important, especially in chemical and pharmaceutical technologies when considering the manufacturing process and the properties of the final product. However, contact angle methods for powders are problematic. The common measurement techniques are the sessile drop method and the liquid penetration method. In this work the determination of contact angles of powders by liquid penetration is considered. In particular, we investigated the influence of the sample preparation and sampling device on the wetting process. A bulk with constant properties during the measurement must be guaranteed. We postulate a packing procedure to obtain reproducible measurements by ensuring constant powder properties. [source]

    F. Scott Fitzgerald's Racial Angles and the Business of Literary Greatness by Michael Nowlin

    First page of article [source]

    Design of a G-Quadruplex Topology through Glycosidic Bond Angles,

    ANGEWANDTE CHEMIE, Issue 48 2009
    Mateus Webba, Silva Dr.
    Baugenehmigung: Bisher wurden neuartige DNA-Quadruplextopologien durch Zufall entdeckt. Mit dem hier vorgestellten System lassen sich nun auf der Grundlage des Winkels der Glycosidbindung von Guanosinen einige Regeln ableiten, um Quadruplextopologien vorherzusagen. Die Methode wurde auf bekannte Strukturen angewendet und genutzt, um neue selbstorganisierte DNA-Quadruplexe zu erhalten. [source]

    Metal,Organic Hendecahedra Assembled from Dinuclear Paddlewheel Nodes and Mixtures of Ditopic Linkers with 120 and 90° Bend Angles,

    ANGEWANDTE CHEMIE, Issue 45 2009
    Jian-Rong Li Dr.
    Von ganz alleine entstehen Metall-organische hendekaedrische Käfige mit dem im Titel genannten Verfahren (siehe Bild). Dieser Ansatz könnte einen neuen Zugang zu komplexen Koordinationspolyedern eröffnen, die über herkömmliche Syntheserouten nicht zugänglich sind. [source]

    The Room-Temperature Superstructure of ZrP2O7 Is Orthorhombic: There Are no Unusual 180° P,O,P Bond Angles.

    CHEMINFORM, Issue 33 2006
    Henrik Birkedal
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]