3g Modes Research Articles

Assessing the value of 3G and 4G network modes in mobile phone pricing

PurposeMobile phone network third-generation (3G) and fourth-generation (4G) modes are the most commonly used modes in many developing countries. This study aims to assess the impact of these network modes and other mobile phone attributes on their retail prices in Pakistan, the fifth most populous and developing country.Design/methodology/approachThis study has been conducted in Punjab province, which shares about 53% of the Pakistan’s population. Hedonic price analysis was carried out on all new mobile phone attributes sold in Punjab’s markets at the retail level. Various econometric tests, that is, Ramsey regression equation specification error, Breusch–Pagan/Cook–Weisberg and variance inflation factor, were calculated to check the robustness of the results.FindingsResults of this study indicated that the mobile phone prices were significantly higher for the sets having 4G network mode than the 3G mode. In addition to this, other mobile phone attributes that significantly influenced their prices were brand, weight, camera, random access memory (RAM), memory size, operating system, battery capacity and display size.Research limitations/implicationsThis study has implications for mobile phone sales and marketing strategies of the manufacturers, importers, retailers and others involved in the mobile phone business in developing countries like Pakistan. Mobile phone manufacturers/importers can increase their profits by producing/importing the 4G enabled devices.Originality/valueAlthough many studies in the literature estimated the implicit price of mobile phone attributes, none of these had explicitly assessed the impact of network mode generation of mobile phones on their prices.

Initial Clinical Experience With a Totally Implantable Cochlear Implant Research Device

To evaluate the effectiveness and issues associated with a research totally implantable cochlear implant (TIKI). Limited patient trial. Tertiary referral center. Three adult human subjects with severe-to-profound sensorineural hearing loss. Subjects were implanted with a research TIKI developed by Cochlear Limited and the Co-operative Research Centre for Cochlear Implant and Hearing Aid Innovation. The TIKI has a lithium ion rechargeable battery, a package-mounted internal microphone, and sound-processing electronics that enable the use of "invisible hearing" without the use of an external device. The TIKI also functions with an external ESPrit 3G sound processor as a conventional cochlear implant. The standard surgical technique was modified to accommodate the larger device package. Postoperatively, subjects used TIKI in both invisible hearing and the conventional ESPrit 3G modes. Device use was recorded in both invisible hearing and ESPrit 3G listening modes. Performance of the internal battery and microphone was assessed over time. Psychophysical MAP data were collected, and speech perception was measured at 1, 3, 6, and 12 months postoperatively in both listening modes. There were no surgical or postoperative complications. All subjects use both invisible hearing and conventional ESPrit 3G modes. Speech perception outcomes for all patients showed improvement from preoperative scores. As a consequence of the reduced sensitivity of the implanted microphone, speech perception results using the invisible hearing mode were significantly lower than the ESPrit 3G mode. Subjects reported some body noise interference that limited use of the invisible hearing mode; however, all continue to use the invisible hearing mode on a limited daily basis. The rechargeable battery functioned well, with a cycle time indicating the low-power implant design is effective and will deliver long battery life. This study demonstrates that the challenges in developing a safe and effective TIKI can be overcome. Three subjects implanted with the research TIKI all reported benefit from routine use. For each subject, hearing outcomes using invisible hearing mode were not as good as when using the external ESPrit 3G sound processor in the conventional mode.

Raman scattering and electrical conductivity of nitrogen implanted MoO 3 whiskers

Whiskers of MoO 3 have been grown by a thermal transport process. A set of samples was then implanted with nitrogen ions at a dose of 5 × 10 16 ion/cm 2. The implanted whiskers changed from transparent to semi-transparent. Raman spectroscopy of the whiskers was observed and compared with those of unimplanted whiskers. The results revealed that the Raman intensity of the implanted whiskers was decreased about 10 times with respect to that of unimplanted whiskers. Only the case of the wave propagation parallel to the a-axis, a lower suppression ratio of the B 3g modes was observed. No extra mode due to the nitrogen implantation was observed. This indicates that implantation could only induce defects and oxygen vacancies but not the structural transformation. From electrical conductivity and Hall measurement, it was found that the whiskers exhibited an n-type semiconductor and its conductivity drastically increased due to the defects and oxygen vacancies.

Electron–phonon interactions and intrinsic nonadiabatic state of superconductors

Study of band structure of YBa 2Cu 3O 7 has shown that electron coupling to A g, B 2g and B 3g modes results in fluctuation of saddle point of one of the CuO plane d-pσ band in Y point of 1st BZ across Fermi level. It represents breakdown of adiabatic Born–Oppenheimer approximation and transition of the system into intrinsic nonadiabatic state, ω > E F. Results show that system is stabilized in this state at distorted nuclear geometry. Stabilization effect is mainly due to strong dependence of the electronic motion on instantaneous nuclear momenta. On the lattice scale, the intrinsic nonadiabatic state is geometrically degenerate at broken translation symmetry – system has fluxional nuclear configuration of O2, O3 atoms in CuO planes. It enables formation of mobile bipolarons that can move in the lattice without dissipation. Described effects are absent in non-superconducting YBa 2Cu 3O 6.

Theoretical studies of the vibrational properties of the 3,4,9,10,-perylene tetracarboxylic dianhydride (PTCDA) molecule

The vibrational properties of the 3,4,9,10,-perylene tetracarboxylic dianhydride (PTCDA) molecule have been computed using different DFT methods, and the resulting vibrational frequencies are assigned to experimental Raman and IR modes of bulk crystals and thin films. For some Raman active B 3g modes, this assignment is performed for the first time. A comparison based on the scalar product of eigenvectors is presented for the different methods of calculation. The best agreement between unscaled calculated frequencies and experimental mode positions in terms of root mean square deviations is obtained for the Becke three parameter Lee–Yang–Parr functional (B3LYP) and the 3-21G basis set.

Infrared and Raman studies of the organic superconductor ϰ-(BEDT-TTF) 2[Cu(NCS) 2] and its 13C(4) isotopic analog

We report on low-temperature infrared reflectivity measurements as well as room-temperature Raman measurements of ϰ-(ET) 2[Cu(NCS) 2] and its 13C(4) isotopic analog, in which the four carbon atoms in the terminal ethylene groups have been substituted. The measured isotopic frequency shifts are used to support previous assignments of the infrared features to A g and B 3g modes. Two Raman spectrometers were used, one using a visible laser and the other an infrared laser. The spectra are very dissimilar, due to the resonant nature of the scattering. The electronic resonance responsible for the infrared-laser Raman scattering appears to be the same as that occurring in the infrared spectrum. We have reassigned v 9(A g) in the infrared spectrum and successfully compare our frequency shifts due to electron—phonon coupling with those recently calculated.

Preparation of YBa 2Cu 4O 8 thin films from precursors deposited by hybrid plasma sputtering through in situ annealing

The processing of YBa 2Cu 4O 8 (Y124) thin films has been investigated by DC 94.92 MHz hybrid plasma sputtering followed by in situ annealing. Precursor films deposited by sputtering in 12.5 mTorr O 2 were annealed in ambient oxygen (1–350 Torr) without taking them out of the deposition chamber. In accordance with different deposition temperatures, the precursors show the textures of the amorphous phase, Y 2BaCuO 5 with the amorphous phase, and YBa 2Cu 3O x and the CuO mixed phase. The amorphous precursor is found to be the best candidate for growing of the Y124 phase through in situ annealing. The vibrational A g modes of the double CuO chain in Y124 are confirmed at 250 and 604 cm −1 by Raman spectroscopy. The B 3g mode is also observed at 311 cm −1, which indicates the film is dominantly a-axis oriented.

Epitaxial quality of c-axis and a-axis oriented YBa 2Cu 3O 7 films Characterization by Raman spectroscopy

We present a model that describes the epitaxial quality of YBa 2Cu 3O 7 films by three parameters — the c-axis oriented fraction of the film, its degree of in-plane orientation and the degree of in-plane orientation of the remaining a-axis oriented fraction. These parameters can be specified by the relative phonon intensities in polarized Raman spectra. We have determined the epitaxy parameters of a-axis and c-axis oriented laser-deposited YBa 2Cu 3O 7 films on MgO (100) substrates. The accuracy of these parameters has been tested by performing Raman measurements at various rotation angles. The ratio of the intensities of the B 2g and B 3g modes observed on the a-axis oriented film indicates that a-axis growth is preferred to b-axis growth.

Theoretical analysis of Franck-Condon and vibronic activity of the a g and b 3g modes in the S 0↔ S 1 transitions in anthracene

The QCFF/PI method and the CNDO/S+CISD method in the floating atomic orbital basis set are used to study Franck-Condon and vibronic activity of the a g and b 3g modes of anthracene in the S 0 ↔ S 1 transition. The calculated intensities of the a g and b 3g fundamentals in the absorption and emission spectra agree reasonably well with the experimental intensities. Modes 6 (a g) and 3 (b 3g) are shown to be the most vibronically active modes in the S 0 ↔ S 1 transition. The calculations indicate that upon excitation to the 1B 1u ( 1L a) state some modes mix strongly. This mixing is shown to be the main source of the breakdown of the mirror-image symmetry between the absorption and emission spectra.

Raman scattering and the antiferromagnetic phase transition in HoCrO 3

The 556 cm -1 A g and 570 cm -1 B 3g modes in the Raman spectrum of HoCrO 3 show an anomalous blue-shift from a little above the Néel temperature to lower temperatures. Between T N and the ordering temperature of the Ho 3+ spins the frequency shift is proportional to the Cr 3+ spin correlation function. Above room temperature the 566 cm -1 mode frequency decreases to 566 cm -1 and then starts to increase to 570 cm -1 at 1000 K. The anomalous increase of scattering intensity of modes with energies higher than 300 cm -1, which appears to be proportional to the correlation function squared, is sensitive to the magnetic ordering. The sensitivity increases with the increase of mode energies. At about 50 K four additional modes appear.

Vibronic activity in the fluorescence and absorption spectrum of pyrene

The vibronic coupling terms responsible for the intensity of the b 3g modes in the absorption and emission spectra of pyrene and pyrene-d 10 have been calculated taking into account both the Herzberg-Teller (HT) mechanism and the Born-Op-penheimer (BO) breakdown mechanism. The calculations have been carried out in the orbital-following scheme, implemented by the INDO/S Hamiltonian. The results, reproducing the main spectral features, such as the large difference observed in the intensity patterns of the two spectra, are discussed in terms of interference between HT and BO mechanisms, isotopic redistribution and the Duschinsky effect.