Transient processes of MoS₂ tribofilm formation under boundary lubrication

A tribochemistry study that involves the application of Raman spectroscopy surface analysis has been undertaken to understand the time-dependent tribochemical reactions, for lubrication by Molybdenum dialkyl-dithiocarbamate (MoDTC) occurring in boundary lubricated conditions. Under the conditions of rubbing and high temperature, time-resolved Raman spectroscopy results show the intermediate steps that lead to the MoDTC additive to be tribochemically structured on the wear scar of the contacting surface. A MoS2 tribofilm with a lattice layer structure is observed on the wear scar whenever the lowest friction was achieved. An apparent shift of the A1g and E2g Raman modes, indicating qualitative and quantitative information on the MoS2 tribofilm formed, is observed to be related to low friction. Detailed analyses of Raman spectra obtained on wear scars at different test durations and temperatures indicate that both temperature and rubbing are needed for the formation of low friction MoS2 tribofilm

Analysis of a Southerly Buster Event and Associated Solitary Waves

This paper is a detailed case study of the southerly buster of October 6-7, 2015, along the New South Wales coast. It takes advantage of recently available Himawari-8 high temporal- and spatial-resolution satellite data, and other observational data. The data analyses support the widespread view that the southerly buster is a density current, coastally trapped by the Great Dividing Range. In addition, it appears that solitary waves develop in this event because the prefrontal boundary layer is shallow and stable. A simplified density current model produced speeds matching well with observational southerly buster data, at both Nowra and Sydney airports. Extending the density current theory, to include inertia-gravity effects, suggests that the solitary waves travel at speeds approximately 20% faster than the density current. This speed difference is consistent with the high-resolution satellite data, which shows the solitary waves moving increasingly ahead of the leading edge of the density current

Negative Giant Longitudinal Magnetoresistance in NiMnSb/InSb: An interface effect

We report on the electrical and magneto-transport properties of the contact formed between polycrystalline NiMnSb thin films grown using pulsed laser deposition (PLD) and n-type degenerate InSb (100) substrates. A negative giant magnetoresistance (GMR) effect is observed when the external magnetic field is parallel to the surface of the film and to the current direction. We attribute the observed phenomenon to magnetic precipitates formed during the magnetic film deposition and confined to a narrow layer at the interface. The effect of these precipitates on the magnetoresistance depends on the thermal processing of the system.Comment: 14 pages, 4 figure

Heavy Flavour Baryons in Hyper Central Model

Heavy flavor baryons containing single and double charm (beauty) quarks with light flavor combinations are studied using the hyper central description of the three-body problem. The confinement potential is assumed as hyper central coulomb plus power potential with power index $\upsilon$. The ground state masses of the heavy flavor, $J^P={1/2}^+$ and ${3/2}^+$ baryons are computed for different power index, $\nu$ starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value in each case of quark combinations beyond the power index $\nu=1.0$.Comment: 10 pages, 4 figure

Magneto-optical investigation of the field-induced spin-glass insulator to ferromagnetic metallic transition of the bilayer manganite (La0.4_{0.4}Pr0.6_{0.6})1.2_{1.2}Sr1.8_{1.8}Mn2_2O7_7

We measured the magneto-optical response of (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$ in order to investigate the microscopic aspects of the magnetic field driven spin-glass insulator to ferromagnetic metal transition. Application of a magnetic field recovers the ferromagnetic state with an overall redshift of the electronic structure, growth of the bound carrier localization associated with ferromagnetic domains, development of a pseudogap, and softening of the Mn-O stretching and bending modes that indicate a structural change. We discuss field- and temperature-induced trends within the framework of the Tomioka-Tokura global electronic phase diagram picture and suggest that controlled disorder near a phase boundary can be used to tune the magnetodielectric response. Remnants of the spin-glass insulator to ferromagnetic metallic transition can also drive 300 K color changes in (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$.Comment: 9 pages, 8 figure

Antispermatogenic Activity of the Benzothiazoline Ligand and Corresponding Organoantimony(V) Derivative in Male Albino Rats

Triphenylantimony(V) derivative, Ph(3)Sb(OPr(i)) [SC(6)H(4)N : C(CH(3))CH(2)C(O)CH(3)], 1b, and the corresponding benzothiazoline ligand [1, 2], [Formula: see text] , 1a, have been tested for their effects on the reproductive system of male albino rats. The oral administration of both 1a and 1b at the dose level of 10 mg/rat/day produced significant reduction in the weights of testes, epididymides, seminal vesicles, and ventral prostate. Significant decrease in sperm motility as well as in sperm density resulted in 100% sterility. Significant (P < .01) alterations were also found in biochemical parameters of reproductive organs in treated male rats as compared to the control group. Production of preleptotene, pachytene, and secondary spermatocytes was decreased by 42%, 43%, 39%, and by 44%, 49%, 55% in the ligand, 1a, and organoantimony(V) derivative, 1b, treated rats, respectively. These results indicate that both compounds 1a and 1b are antispermatogenic in nature and on oral administration in male rats, and finally caused sterility. A comparison indicates that the organoantimony(V) derivative 1b is more effective pertaining to its antispermatogenic activity than the corresponding ligand 1a

Tuberculosis of the talus in a 2-year-old: a diagnostic dilemma

Extra-pulmonary tuberculosis involving the ankle and foot is a rare entity with its prevalence being ever rarer in the pediatric population. Here, we report the case of a two-year-old female child who presented with a gradually progressive non-traumatic swelling involving the right foot and ankle since two months. The patient was initially managed by a local doctor with immobilization of the foot and ankle in a slab for three weeks. Blood investigations were suggestive of an inflammatory process and a lytic lesion involving the talus was seen on radiographs. The patient was managed with debridement and curettage of the lesion along with anti-tubercular chemotherapy as per pediatric dosage for one year. The patient was asymptomatic at latest follow-up of one year and radiographs showed that lytic lesion had resolved

Lepton polarization asymmetry in radiative dileptonic B-meson decays in MSSM

In this paper we study the polarization asymmetries of the final state lepton in the radiative dileptonic decay of B meson (\bsllg) in the framework of Minimal Supersymmetric Standard Model (MSSM) and various other unified models within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of universality of scalar masses is relaxed) etc. Lepton polarization, in addition of having a longitudinal component (\pl), can have two other components, \pt and \pn, lying in and perpendicular to the decay plane, which are proportional to \ml and hence are significant for final state being $\mu^+ ~ \mu^-$ or $\tau^+ \~\tau^-$. We analyse the dependence of these polarization asymmetries on the parameters of the various models.Comment: typos corrected to match with published versio