1,326 research outputs found
Fifth-order nonlinear susceptibility: Effect of third-order resonances in a classical theory
We compute the fifth-order nonlinear susceptibility in the frame of a classical model based on an anharmonic oscillator, taking into account the local field corrections. A third-harmonic resonance is evidenced, which explains the strong enhancement of some measured values of the corresponding nonlinear index and its sign changes with the wavelength. The ratio between the fifth-order nonlinear index and the fifth-order nonlinear absorption is computed and is in good agreement with experimental data measured in carbon disulfide CS2
Determination of the third- and fifth-order optical nonlinearities: the general case
We compute the evolution of the intensity (I) and the phase (phi) of a beam propagating in a nonlinear (NL) isotropic medium exhibiting third- and fifth-order NL optical characteristics. All formulas are analytic, but the general case requires a numerical inversion by means of Newton’s method. The solutions may differ if some coefficients vanish, so they are given in all cases up to the fifth-order nonlinearities. The analytical relations allow us to fit the experimental data using the recently introduced D4sigma-Z-scan method. Carbon disulfide is tested at 532 and 1,064 nm in the picosecond regime deducing NL coefficients related to third- and fifth-order optical susceptibilities
Jilbab sebagai Simbol Komunikasi di Kalangan Mahasiswa Universitas Hasanuddin (Studi Komunikasi Nonverbal)
This research is a study of nonverbal communication behaviors of students covered by a descriptive qualitative. Inthis study obtained of 145 studens which wearing veil as a sample, withc cluster sampling technique in which aquota sample drawn by the percentage of 2% of each faculty. To obtain data conducted by distributingquiestionaries, in depth interviewes, direct observation and literature study, then analyzed qualitatively. Discussionof this research uses the concept of nonverbal communication and the concept of symbolic interactionism byBlumer. Result showed that student's view on the hijab covering ideology, adaptation and identity. From the contextof Islamic ideology, “Clothes are mandatory for Muslims who have entered legally Baligh, because the commandsare written clearly covered in the Qur'an, where Muslim women are prohibited from revealing private parts exceptthe face and hands.” From the context of identity, “just as life-style headscarf.” More students to consider problemsand models wearing the headscarf that matched rather than syar'i according to Islam, and the trend is more the issuethan the issue of religious obligation. From the context of adaptation, ‘significant other' very influental on thebehavior of students wearing the hijab as parents and family, and veiled student behavior based on a communityreference group. Students inclined have as a friend that similarity through ideology, vision in veil, hobby or style:“cognitive consistency”
Filamentation of light in carbon disulfide
We report experimental observation of light filamentation in carbon disulfide (CS2). Accurate measurements of the nonlinear index show an unusual saturation law of the Kerr effect, which is used to build a model of light propagation in CS2, which describes the filamentation in good agreement with experimental observations
Scarf osteotomy versus metatarsophalangeal arthrodesis in forefoot first ray disorders: Comparison of functional outcomes
SummaryIntroductionScarf osteotomies of the first metatarsal and metatarsophalangeal arthrodesis are the two most frequent surgical forefoot reconstructive procedures.HypothesisWe compared functional results of isolated arthrodesis of the first metatarsophalangeal joint with an isolated Scarf osteotomy of the first metatarsal.Materials and methodsThis was a retrospective, observational, continuous study of patients operated between 1993 and 2008. After patients who had undergone a procedure on the lateral rays, extremely elderly patients, lost to follow-up patients and those with incomplete questionnaires had been excluded, there remained two comparable groups of 25 patients. Mean age was 60 in the arthrodesis group [41–70] and 59.8 in the Scarf group [47–71]. The Scarf group included 25 hallux valgus (100%) compared to 16 hallux valgus (64%) and nine hallux rigidus (36%) in the arthrodesis group. Complications were recorded. Evaluation of functional results was based on the most recent functional or quality of life scores (AOFAS, FFI, FAAM, SF 36) and a questionnaire on physical and athletic ability.ResultsThere was no significant difference in the rate of complications between the two groups. There was no difference in pain according to the AOFAS score with 35.6/40 (±6.5) in the Scarf group and 34.5 (±5.9) in the arthrodesis group. Global satisfaction was also similar between the Scarf and arthrodesis groups: 91.4% and 90% of very satisfied or satisfied patients, respectively. The FFI score was higher in the Scarf group than in the arthrodesis group: 8.6 (±20.1) and 19.8 (±17.7) respectively. Functional results were better in the Scarf group than in the arthrodesis group with a FAAM Daily Activity score of 80.2 (±12.1) compared to 68 (±7.2), a FAAM Sports Activity score of 29.7 (±6.7) compared to 25.2 (±7.6) and a FAAM Global Function score of 94% (±10.8) compared to 87% (±15.7), respectively. The Global SF36 score was higher in the Scarf group than in the arthrodesis group: 70.9% (±14.1) and 62.3% (±20.6) respectively, which was due to a higher Mental Health score in the Scarf group: 68.7% (±14.2) and 60.4% (±19.3) respectively. In the area of sports activities the Scarf group practiced more hiking than the arthrodesis group (74% versus 42% respectively). There was no difference for other activities.Discussion and conclusionThis study provides detailed information on the level of physical and sports activities that are practiced following these procedures, so that the patient can be better informed.Level of evidenceLevel III. Comparative retrospective
Nonlinear characterization of materials using the D4σ method inside a Z-scan 4f-system
We show that direct measurement of the beam radius in Z-scan experiments using a CCD camera at the output of a 4f -imaging system allows higher sensitivity and better accuracy than Baryscan. One of the advantages is to be insensitive to pointing instability of pulsed lasers because no hard (physical) aperture is employed as in the usual Z-scan. In addition, the numerical calculations involved here and the measurement of the beam radius are simplified since we do not measure the transmittance through an aperture and it is not subject to mathematical artifacts related to a normalization process, especially when the diffracted light intensity is very low
D4σ nonlinear measurement inside a 4f-Z-scan system
The D4σ method using a 4f-Z-scan system is presented in order to increase the sensitivity and the resolution in Z-scan measurements. The numerical calculations and the experimental results validate our approach
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