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Position Changes (position + change)
Selected AbstractsStructure,Property Relationship of Pyridine-Containing Triphenyl Benzene Electron-Transport Materials for Highly Efficient Blue Phosphorescent OLEDsADVANCED FUNCTIONAL MATERIALS, Issue 8 2009Shi-Jian Su Abstract Three triphenyl benzene derivatives of 1,3,5-tri(m -pyrid-2-yl-phenyl)benzene (Tm2PyPB), 1,3,5-tri(m -pyrid-3-yl-phenyl)benzene (Tm3PyPB) and 1,3,5-tri(m -pyrid-4-yl-phenyl)benzene (Tm4PyPB), containing pyridine rings at the periphery, are developed as electron-transport and hole/exciton-blocking materials for iridium(III) bis(4,6-(di-fluorophenyl)pyridinato- N,C2,)picolinate (FIrpic)-based blue phosphorescent organic light-emitting devices. Their highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) energy levels decrease as the nitrogen atom of the pyridine ring moves from position 2 to 3 and 4; this is supported by both experimental results and density functional theory calculations, and gives improved electron-injection and hole-blocking properties. They exhibit a high electron mobility of 10,4,10,3,cm2,V,1,s,1 and a high triplet energy level of 2.75,eV. Confinement of FIrpic triplet excitons is strongly dependent on the nitrogen atom position of the pyridine ring. The second exponential decay component in the transient photoluminescence decays of Firpic-doped films also decreases when the position of the nitrogen atom in the pyridine ring changes. Reduced driving voltages are obtained when the nitrogen atom position changes because of improved electron injection as a result of the reduced LUMO level, but a better carrier balance is achieved for the Tm3PyPB-based device. An external quantum efficiency (EQE) over 93% of maximum EQE was achieved for the Tm4PyPB-based device at an illumination-relevant luminance of 1000,cd,m,2, indicating reduced efficiency roll-off due to better confinement of FIrpic triplet excitons by Tm4PyPB in contrast to Tm2PyPB and Tm3PyPB. [source] An in vitro comparison of canal preparation using two automated rotary nickel,titanium instrumentation techniquesINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2000S. J. Jardine Abstract Aim The aim of this study was to compare the efficacy of root canal preparation using two automated rotary nickel,titanium instrumentation techniques with a double flared balanced forces hand preparation technique, using stainless steel files in extracted human teeth. Methodology Sixty root canals in extracted human teeth were matched for curvature, length and diameter and divided evenly between three groups (group 1 = double flare using Flexofiles®, group 2 = rotary nickel,titanium using McXIM® instruments and group 3 = rotary nickel,titanium using Profile® .04 TaperTM Series 29 instruments). The instruments were used according to the manufacturer's instructions in a torque controlled motor and handpiece (groups 2 and 3) and according to a predetermined procedure in group 1. A standardized radiographic technique using mercury as a contrast medium was used to evaluate the canal shape before and after preparation in the plane of maximum curvature. The pre- and postoperative radiographic images were compared against each other and with a predicted ,ideal preparation' calculated from a projection of the final instrument dimensions. The outcome measures were changes in canal dimensions as quantified by measuring the changes in the position of the inner and outer wall at 1 mm intervals. Alteration in canal curvature could be inferred by comparison with the ideal preparation. Results The degree of canal curvature did not influence the effectiveness of any of the techniques. The results showed no statistically significant differences in the outcome measures between the groups (two-way anova). There were no significant differences in canal wall position changes at any level except the apical three, where significantly less change occurred in all groups (P = 1%). Instruments fractured in three canals, with acute curves in groups 2 and 3. Conclusions Canal curvatures were equally and well maintained following preparation in all the groups, as long as the instrument did not fracture. [source] ,Partnership': a co-operative inquiry between community mental health nurses and their clients.JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 4 2000The aim of this study was to explore the utility of co-operative enquiry between community mental health nurses and their clients. The research design was a form of co-operative enquiry. Two nurses and two clients volunteered to participate as co-researchers and co-subjects with two facilitators in a co-operative inquiry group. The subject of the inquiry, agreed by the group, was the relationship between the nurse and client. The method for the inquiry was developed by the participants and consisted of dialogue groups. This paper provides a description of the research design and methodology with a first-person account of the research experience and reflections by the two facilitators. The process is considered with particular reference to the influence of the study facilitators. Their position changes from wanting to influence an ,external' relationship to one of being influenced within the research relationship over time through reflection and growing self-awareness. This results in the inquiry ultimately being driven by the agenda of the group rather than the process. The outcomes of the study were both informative and transformative and the content of the inquiry relating to the nurse,client relationship will be presented in a second paper. [source] Effect of infants' position on serum bilirubin level during conventional phototherapyACTA PAEDIATRICA, Issue 8 2010ML Donneborg Abstract Aim:, To compare the decrease in total serum bilirubin (TSB) concentration during conventional phototherapy in infants treated in supine position exclusively versus infants alternated between exposure in supine and prone position every third hour. Moreover, to survey current practice patterns in two Scandinavian countries as far as alternating exposure. Methods:, A total of 112 infants with non-haemolytic hyperbilirubinaemia, but otherwise healthy, and a gestational age ,33 weeks were randomized to one of the treatment groups. All infants received phototherapy for 24 h. TSB was measured at start of phototherapy and after 12 and 24 h of treatment. Questionnaires about routines for position changes in infants during phototherapy were sent to all 41 neonatal departments in Denmark and Norway. Results:, No statistically significant differences in the decrease in TSB were observed between the two treatment groups: at 12 h of therapy, TSB decreased 32% in both groups and at 24 h 49% and 50%, respectively. In two-thirds of Danish and Norwegian departments, the infants were routinely turned during phototherapy, most often every third hours. Conclusion:, The decrease in TSB was not significantly associated with positioning of the infant during conventional phototherapy. Alternating exposure is widely practiced in Scandinavia but is unnecessary. [source] New micromachined interdigital coplanar waveguideMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2007Xiaofeng Sun Abstract A novel interdigital coplanar waveguide (CPW) has been designed and fabricated and its characteristics have been studied as a function of transmission line parameters. In this interdigital CPW, the ground conductors are thickened by micromachining techniques, which are helpful for reducing the interference between the adjacent parallel sections of center conductor. Within the frequency range from 5 to 20 GHz, the return loss of this structure has two minimal values whose positions change with the structural parameters. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1007,1010, 2007; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.22336 [source] | ||||||||||