Lateral distribution of high energy hadrons and gamma ray in air shower cores observed with emulsion chambers

A high energy event of a bundle of electrons, gamma rays and hadronic gamma rays in an air shower core were observed. The bundles were detected with an emulsion chamber with thickness of 15 cm lead. This air shower is estimated to be initiated with a proton with energy around 10 to the 17th power to 10 to the 18th power eV at an altitude of around 100 gmc/2. Lateral distributions of the electromagnetic component with energy above 2 TeV and also the hadronic component of energy above 6 TeV of this air shower core were determined. Particles in the bundle are produced with process of the development of the nuclear cascade, the primary energy of each interaction in the cascade which produces these particles is unknown. To know the primary energy dependence of transverse momentum, the average products of energy and distance for various average energies of secondary particles are studied

Strong-coupling Spin-singlet Superconductivity with Multiple Full Gaps in Hole-doped Ba0.6_{0.6}K0.4_{0.4}Fe2_2As2_2 Probed by Fe-NMR

We present $^{57}$Fe-NMR measurements of the novel normal and superconducting-state characteristics of the iron-arsenide superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ ($T_c$ = 38 K). In the normal state, the measured Knight shift and nuclear spin-lattice relaxation rate $(1/T_1)$ demonstrate the development of wave-number ($q$)-dependent spin fluctuations, except at $q$ = 0, which may originate from the nesting across the disconnected Fermi surfaces. In the superconducting state, the spin component in the $^{57}$Fe-Knight shift decreases to almost zero at low temperatures, evidencing a spin-singlet superconducting state. The $^{57}$Fe-$1/T_1$ results are totally consistent with a $s^\pm$-wave model with multiple full gaps, regardless of doping with either electrons or holes.Comment: 4 pages, 4 figures, 1 tabl

The retroflection of part of the East Greenland Current at Cape Farewell

The East Greenland Current (EGC) and the smaller East Greenland Coastal Current (EGCC) provide the major conduit for cold fresh polar water to enter the lower latitudes of the North Atlantic. They flow equatorward through the western Irminger Basin and around Cape Farewell into the Labrador Sea. The surface circulation and transport of the Cape Farewell boundary current region in summer 2005 is described. The EGCC merges with Arctic waters of the EGC to the south of Cape Farewell, forming the West Greenland Current. The EGC transport decreases from 15.5 Sv south of Cape Farewell to 11.7 Sv in the eastern Labrador Sea (where the water becomes known as Irminger Sea Water). The decrease in EGC transport is balanced by the retroflection of a substantial proportion of the boundary current (5.1 Sv) into the central Irminger Basin; a new pathway for fresh water into the interior of the subpolar gyre

Spatial distribution and habitat characterisation of mosquito species in the lake and land habitats of western Kenya

Background: Infections with mosquito-borne parasites are common in humanpopulations inhabiting tropical regions of the world. Malaria is endemic along Kenyan Lake Victoria basin and its vectors are fresh water breeders. However, much less is known about the current spatial distribution and habitat characterisation of mosquitoes including vectors of malaria in the lake waters and adjacent terrestrial aquatic habitats.Objectives: To characterise mosquito larval habitats and to determine the spatialdistribution of mosquito species in lake and land habitats, measure aquatic habitats’ (water) physic-chemical parameters, enumerate the number of phytoplankton, zooplankton and fish species and determine their effects on the abundance of mosquitoes. This could allow larval control to be more effectively targeted at specific sites which in its turn could reduce malaria transmission in the area.Design: Cross-sectional study.Setting: The Kenyan Lake Victoria Basin.Results: Anopheles and Culex species of mosquitoes were absent in different locations in the lake, but abundant in different aquatic habitats in different locations on land. There was heterogeneity in the relative abundance of Anopheles and Culex species in the aquatic habitats in different locations on land, p<0.001, Bartlett’s test. There were more Anopheles mosquito in quary and shoreline swamp puddles, flood plain, and stream edge puddles than natural swamps, rivers and permanent ponds habitats, P<0.001. There was no significant correlation of the abundance of Anopheles and physico-chemical parameters, P>0.05 (Pearsons correlation coefficiency). Also, there was no significant correlation between abundance of Anopheles mosquitoes and phytoplanktons, (P>0.05). Significant correlation was however, observed with Dinoflagellates on land, P=0.014. Clarias gariepinus were more insectivorous compared to Oreochromis niloticus, which mostly fed on zooplankton and food remains. The most abundant mosquitoes in the lake were Mansonia followed by Aedes species of mosquitoes.Conclusion: Anopheles species of mosquitoes do not breed in deep permanent lake waters even if it is heavily infested by water hyacinth and other aquatic weeds. However, they breed in temporary or seasonal aquatic land habitats such as pools and swamps, more so when infested by aquatic and other vegetations. We recommend that, focus of malaria vector control should concentrate on land sites. Health education and awareness programs should be scaled up to inform the local communities on mosquito species ecology in relation to transmission of malaria and other mosquito- borne diseases. There is need to introduce certain fish species (Clarias gariepinus) for biological control of mosquitoes breeding in the aquatic habitats near human habitats

Continuity of Local Time: An applied perspective

Continuity of local time for Brownian motion ranks among the most notable mathematical results in the theory of stochastic processes. This article addresses its implications from the point of view of applications. In particular an extension of previous results on an explicit role of continuity of (natural) local time is obtained for applications to recent classes of problems in physics, biology and finance involving discontinuities in a dispersion coefficient. The main theorem and its corollary provide physical principles that relate macro scale continuity of deterministic quantities to micro scale continuity of the (stochastic) local time.Comment: To appear in: "The fascination of Probability, Statistics and Their Applications. In honour of Ole E. Barndorff-Nielsen on his 80th birthday

Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3

Spontaneous symmetry breaking is an important concept for understanding physics ranging from the elementary particles to states of matter. For example, the superconducting state breaks global gauge symmetry, and unconventional superconductors can break additional symmetries. In particular, spin rotational symmetry is expected to be broken in spin-triplet superconductors. However, experimental evidence for such symmetry breaking has not been conclusively obtained so far in any candidate compounds. Here, by 77Se nuclear magnetic resonance measurements, we show that spin rotation symmetry is spontaneously broken in the hexagonal plane of the electron-doped topological insulator Cu0.3Bi2Se3 below the superconducting transition temperature Tc=3.4 K. Our results not only establish spin-triplet superconductivity in this compound, but may also serve to lay a foundation for the research of topological superconductivity

Size distributions of air showers accompanied with high energy gamma ray bundles observed at Mt. Chacaltaya

Size distributions of air showers accompanied with bundle of high energy gamma rays and/or large size bursts under emulsion chambers, to study the composition of primary cosmic rays and also characteristics of high energy nuclear interaction. Air showers initiated by particles with a large cross section of interaction may develop from narrow region of the atmosphere near the top. Starting levels of air showers by particles with smaller cross section fluctuate in wider region of the atmosphere. Air showers of extremely small size accompanied with bundle of gamma rays may be ones initiated by protons at lower level after penetrating deep atmosphere without interaction. It is determined that the relative size distribution according to the total energy of bundle of gamma rays and the total burst size observed under 15 cm lead absorber

All functions are (locally) ss-harmonic (up to a small error) - and applications

The classical and the fractional Laplacians exhibit a number of similarities, but also some rather striking, and sometimes surprising, structural differences. A quite important example of these differences is that any function (regardless of its shape) can be locally approximated by functions with locally vanishing fractional Laplacian, as it was recently proved by Serena Dipierro, Ovidiu Savin and myself. This informal note is an exposition of this result and of some of its consequences

High energy hadrons in EAS at mountain altitude

An extensive simulation has been carried out to estimate the physical interpretation of dynamical factors such as , in terms of high energy interaction features, concentrated in the present analysis on the average transverse momentum. It appears that the large enhancement observed for versus primary energy, suggesting in earliest analysis a significant rise of with energy, is only the result of the limited resolution of the detectors and remains in agreement with a wide range of models used in simulations.Comment: 13 pages, 6 PostScript figures, LaTeX Subm. to JPhys

Diffusive Spreading of Chainlike Molecules on Surfaces

We study the diffusion and submonolayer spreading of chainlike molecules on surfaces. Using the fluctuating bond model we extract the collective and tracer diffusion coefficients D_c and D_t with a variety of methods. We show that D_c(theta) has unusual behavior as a function of the coverage theta. It first increases but after a maximum goes to zero as theta go to one. We show that the increase is due to entropic repulsion that leads to steep density profiles for spreading droplets seen in experiments. We also develop an analytic model for D_c(theta) which agrees well with the simulations.Comment: 3 pages, RevTeX, 4 postscript figures, to appear in Phys. Rev. Letters (1996