The whistler nozzle phenomenon

The whistler nozzle is a simple device which can induce jet self-excitations of controllable amplitudes and frequencies and appears highly promising for many applications involving turbulent transport, combustion and aerodynamic noise. The characteristics of this curious phenomenon are documented for different values of the controlling parameters and attempts to explain the phenomenon. It is shown that the whistler excitation results from the coupling of two independent resonance mechanisms: shear-layer tone resulting from the impingement of the pipe-exit shear layer on the collar lip, and organ-pipe resonance of the pipe-nozzle. The crucial role of the shear-layer tone in driving the organ-pipe resonance is proven by reproducing the event in pipe-ring and pipe-hole configurations in the absence of the collar. It is also shown that this phenomenon is the strongest when the self-excitation frequency matches the preferred mode of the jet

2D Carbon-based Device Design, Simulation and Electrical Characterization

Due to the scaling of the device dimension, device performance is getting limited day by day. Researchers are facing new challenges in quest of sustainable solutions in device architecture and material characterization. 2D carbon-based materials are posing outstanding electrical and thermal properties; novel materials can be exploited in the electrical transport mechanism by improving device architecture. Carbon and nanodiamond-based materials are characterized in MOSFET-type device architecture for further improvement. Besides, delta-doped silicon MOSFET is simulated to overcome the shortcomings in short channel effects. The flyer for the event can be downloaded by clicking on the blue download button

Topological aspect of graphene physics

Topological aspects of graphene are reviewed focusing on the massless Dirac fermions with/without magnetic field. Doubled Dirac cones of graphene are topologically protected by the chiral symmetry. The quantum Hall effect of the graphene is described by the Berry connection of a manybody state by the filled Landau levels which naturally possesses non-Abelian gauge structures. A generic principle of the topologically non trivial states as the bulk-edge correspondence is applied for graphene with/without magnetic field and explain some of the characteristic boundary phenomena of graphene.Comment: 12 pages, 8 figures. Proceedings for HMF-1

Semimetal to semimetal charge density wave transition in 1T-TiSe2_2

We report an infrared study on 1$T$-TiSe$_2$, the parent compound of the newly discovered superconductor Cu$_x$TiSe$_2$. Previous studies of this compound have not conclusively resolved whether it is a semimetal or a semiconductor: information that is important in determining the origin of its unconventional CDW transition. Here we present optical spectroscopy results that clearly reveal that the compound is metallic in both the high-temperature normal phase and the low-temperature CDW phase. The carrier scattering rate is dramatically different in the normal and CDW phases and the carrier density is found to change with temperature. We conclude that the observed properties can be explained within the scenario of an Overhauser-type CDW mechanism.Comment: 4 pages, 4 page

Charge collective modes in an incommensurately modulated cuprate

We report the first measurement of collective charge modes of insulating Sr14Cu24O41 using inelastic resonant x-ray scattering over the complete Brillouin zone. Our results show that the intense excitation modes at the charge gap edge predominantly originate from the ladder-containing planar substructures. The observed ladder modes (E vs. Q) are found to be dispersive for momentum transfers along the "legs" but nearly localized along the "rungs". Dispersion and peakwidth characteristics are similar to the charge spectrum of 1D Mott insulators, and we show that our results can be understood in the strong coupling limit (U >> t_{ladder}> t_{chain}). The observed behavior is in marked contrast to the charge spectrum seen in most two dimensional cuprates. Quite generally, our results also show that momentum-tunability of inelastic scattering can be used to resolve mode contributions in multi-component incommensurate systems.Comment: 4+ pages, 5 figure

Peran Terapi Akupunktur Pada Nyeri Tulang Metastasis

Bone pain caused by cancer is a common complication in bone metastasis. Bone pain has the characteristic triad of pain including continuous pain, spontaneous pain and incident pain. Various mechanisms that allow bone metastasis can cause pain have been reported. These mechanisms include the possibility of local production of growth factors and cytokines. The management of the pain bone metastasis include aspects of pharmacological and non-pharmacological therapies. Acupuncture can play a role in the treatment of bone metastasis pain through modulation of various neurotransmitters and increase the production of endogenous opioids that can cause analgesika effect. This paper describes a male patient aged 62 years old with painful bone metastasis who experience an improvement after acupuncture therapy, with the goal of providing information on the possible use of acupuncture for painful bone metastasis