Sublimation of ice particles from rocket exhausts in the upper atmosphere

The process of sublimation of ice particles from a rocket exhaust in the upper atmosphere is examined. Heating by solar radiation and losses of energy by means thermal radiation and sublimation are taken into account in the thermal balance of the ice particles. The time dependences of size and temperature of the ice particles are obtained. An estimation of water vapor concentration around the rocket trajectory is made. The process of sublimation of the rocket exhaust ice particles may be important for the interpretation of optical phenomena in the upper atmosphere connected with rocket launches and for propagation of disturbances at a large distance from the rocket

Suggestopedic mobile language learning

The use of suggestopedic teaching methods has been shown to be effective in the domain of language learning. Suggestopaedia is a classroom teaching method that employs certain strategies to enable learners to relax in order to enable more effective learning both consciously and subconsciously. The use of mobile technologies to support language learning has also become very useful and popular. This paper proposes the amalgamation of the two approaches to enable a mobile suggestopedic platform and demonstrates empirical evidence linked to the success of this approach on languge learning. The design of a Suggestopedic mobile language learning app is discussed together with different target groups of learners that can benefit from this type of teaching. Design, development and evaluation of this app forms our future work

Investigation of defect cavities formed in three-dimensional woodpile photonic crystals

We report the optimisation of optical properties of single defects in three-dimensional (3D) face-centred-cubic (FCC) woodpile photonic crystal (PC) cavities by using plane-wave expansion (PWE) and finite-difference time-domain (FDTD) methods. By optimising the dimensions of a 3D woodpile PC, wide photonic band gaps (PBG) are created. Optical cavities with resonances in the bandgap arise when point defects are introduced in the crystal. Three types of single defects are investigated in high refractive index contrast (Gallium Phosphide-Air) woodpile structures and Q-factors and mode volumes ($V_{eff}$) of the resonant cavity modes are calculated. We show that, by introducing an air buffer around a single defect, smaller mode volumes can be obtained. We demonstrate high Q-factors up to 700000 and cavity volumes down to $V_{eff}<0.2(\lambda/n)^3$. The estimates of $Q$ and $V_{eff}$ are then used to quantify the enhancement of spontaneous emission and the possibility of achieving strong coupling with nitrogen-vacancy (NV) colour centres in diamond.Comment: 12 pages, 11 figure

Penatalaksanaan Pada Pasien Ulkus Kornea Dengan Prolaps Iris Oculi Sinistra

Latar Belakang. Pembentukan parut akibat ulserasi kornea adalah penyebab utama kebutaan dan ganguan penglihatan di seluruh dunia. Ulkus kornea adalah keadaan patologik kornea yang ditandai oleh adanya infiltrat supuratif disertai defek kornea bergaung, diskontinuitas jaringan kornea dapat terjadi dari epitel sampai stroma. Ulkus kornea yang sembuh akan menimbulkan kekeruhan kornea dan merupakan penyebab kebutaan nomor dua di Indonesia. Insiden ulkus kornea tahun 1993 adalah 5,3 juta per 100.000 penduduk di Indonesia, sedangkan predisposisi terjadinya ulkus kornea antara lain terjadi karena trauma, pemakaian lensa kontak, dan kadang-kadang tidak diketahui penyebabnya. Tujuan penulisan ini adalah teridentifikasinya faktor-faktor yang mempengaruhi terjadinya penyakit pasien, serta penatalaksanaan pasien secara tepat. Metode. Laporan kasus di Rumah Sakit Abdul Moeloek pada bulan Juli 2012 yang ditelaah berdasarkan evidence based medicine. Hasil. Tn. K, 70 tahun, dengan keluhan mata kiri tidak dapat melihat sejak 2 minggu yang lalu. Keluhan tersebut disertai dengan mata yang tampak merah, membengkak dan bagian mata kiri tampak keluar. Pada pemeriksaan fisik didapatkan Tekanan darah : 160/100mmHg, nadi: 92x/menit, frekuensi napas: 20x/menit, suhu:36,7oC. Mata: Oculi sinistra : visus: 0, palpebra superior: Hiperemis, nyeri positif, konjungtiva: mix injection, kornea: perforasi, camera oculi anterior: hipopion, iris: prolaps, pupil: sulit dinilai, lensa: sulit dinilai. Oculi dekstra : dalam batas normal. Pemeriksaan penunjang yang dilakukan didapatkan : Haemoglobin : 15,3 gr/dL, Hematokrit: 46%, Laju endap darah: 10 mm/jam, Leukosit : 10.500 ul, Trombosit : 257.000 ul. Simpulan. Ulkus kornea adalah keadaan patologik kornea yang ditandai oleh adanya infiltrat supuratif disertai defek kornea bergaung, diskontinuitas jaringan kornea dapat terjadi dari epitel sampai stroma. [Medula.2013;1:80-89

Convexity properties of the condition number II

In our previous paper [SIMAX 31 n.3 1491-1506(2010)], we studied the condition metric in the space of maximal rank matrices. Here, we show that this condition metric induces a Lipschitz-Riemann structure on that space. After investigating geodesics in such a nonsmooth structure, we show that the inverse of the smallest singular value of a matrix is a log-convex function along geodesics (Theorem 1). We also show that a similar result holds for the solution variety of linear systems (Theorem 31). Some of our intermediate results, such as Theorem 12, on the second covariant derivative or Hessian of a function with symmetries on a manifold, and Theorem 29 on piecewise self-convex functions, are of independent interest. Those results were motivated by our investigations on the com- plexity of path-following algorithms for solving polynomial systems.Comment: Revised versio

Development of a Classical Force Field for the Oxidised Si Surface: Application to Hydrophilic Wafer Bonding

We have developed a classical two- and three-body interaction potential to simulate the hydroxylated, natively oxidised Si surface in contact with water solutions, based on the combination and extension of the Stillinger-Weber potential and of a potential originally developed to simulate SiO2 polymorphs. The potential parameters are chosen to reproduce the structure, charge distribution, tensile surface stress and interactions with single water molecules of a natively oxidised Si surface model previously obtained by means of accurate density functional theory simulations. We have applied the potential to the case of hydrophilic silicon wafer bonding at room temperature, revealing maximum room temperature work of adhesion values for natively oxidised and amorphous silica surfaces of 97 mJ/m2 and 90mJ/m2, respectively, at a water adsorption coverage of approximately 1 monolayer. The difference arises from the stronger interaction of the natively oxidised surface with liquid water, resulting in a higher heat of immersion (203 mJ/m2 vs. 166 mJ/m2), and may be explained in terms of the more pronounced water structuring close to the surface in alternating layers of larger and smaller density with respect to the liquid bulk. The computed force-displacement bonding curves may be a useful input for cohesive zone models where both the topographic details of the surfaces and the dependence of the attractive force on the initial surface separation and wetting can be taken into account

Onset of a boson mode at superconducting critical point of underdoped YBa2Cu3Oy

The thermal conductivity $\kappa$ of underdoped \Y was measured in the $T \to 0$ limit as a function of hole concentration $p$ across the superconducting critical point at $p_{SC}$ = 5.0%. ``Time doping'' was used to resolve the evolution of bosonic and fermionic contributions with high accuracy. For $p \leqslant p_{SC}$, we observe an additional $T^3$ contribution to $\kappa$ which we attribute to the boson excitations of a phase with long-range spin or charge order. Fermionic transport, manifest as a linear term in $\kappa$, is seen to persist unaltered through $p_{SC}$, showing that the state just below $p_{SC}$ is a thermal metal. In this state, the electrical resistivity varies as log$(1/T)$ and the Wiedemann-Franz law is violated

Microscopic Description of Band Structure at Very Extended Shapes in the A ~ 110 Mass Region

Recent experiments have confirmed the existence of rotational bands in the A \~ 110 mass region with very extended shapes lying between super- and hyper-deformation. Using the projected shell model, we make a first attempt to describe quantitatively such a band structure in 108Cd. Excellent agreement is achieved in the dynamic moment of inertia J(2) calculation. This allows us to suggest the spin values for the energy levels, which are experimentally unknown. It is found that at this large deformation, the sharply down-sloping orbitals in the proton i_{13/2} subshell are responsible for the irregularity in the experimental J(2), and the wave functions of the observed states have a dominant component of two-quasiparticles from these orbitals. Measurement of transition quadrupole moments and g-factors will test these findings, and thus can provide a deeper understanding of the band structure at very extended shapes.Comment: 4 pages, 3 eps figures, final version accepted by Phys. Rev. C as a Rapid Communicatio