Abstract: This article aims to study the effects of shock-disturbed cracks on the cutting features of cone bits. By utilizing the Walsh’s model, a crack model was established for the damaged rock surrounding the induced hole, the intrusive coefficient of the cone bit was derived, and the drilling rate equation around the induced hole was formulated. The effects of crack density and disturbance ...

The electron density as measured in the transition region of a coronal hole, a ‘quiet’ Sun region at disk center plus an active region shows variations of up to a factor of two at Te ∼ 1.5 105 K, lasting at most only a few minutes. There is remarkable agreement between the number of such variations, their temporal variability and duration in the coronal hole and ‘quiet’ Sun datasets, consistent...

We measure gate-tuned thermoelectric power of mechanically exfoliated Bi2Se3 thin films in the topological insulator regime. The sign of the thermoelectric power changes across the charge neutrality point as the majority carrier type switches from electron to hole, consistent with the ambipolar electric field effect observed in conductivity and Hall effect measurements. Near the charge neutrali...

Under the assumption that the Milky Way’s dark halo consists of primordial black hole MACHOs (PBHMACHOs), the mass density of the halo can be measured by the low frequency gravitational waves (10 Hz ∼< νgw ∼< 10 Hz) from PBHMACHO binaries whose fraction is ∼ 10. We find that ten years observation by LISA will detect ∼ 700 PBHMACHO binaries and enable us to determine the power index of the densi...

We present a cosmologically-motivated model in which the seeds of supermassive black holes form out of the lowest angular momentum gas in proto-galaxies at high redshift. We show that under reasonable assumptions, this leads naturally to a correlation between black hole masses and spheroid properties, as observed today. We assume that the gas in early-forming, rare-peak haloes has a distributio...

Motivated by recent observational results that focus on high-redshift black holes, we explore the effect of scatter and observational biases on the ability to recover the intrinsic properties of the black hole population at high redshift. We find that scatter and selection biases can hide the intrinsic correlations between black holes and their hosts, with ‘observable’ subsamples of the whole p...

In the present work the approach-density matrix deformation-earlier developed by the author to study a quantum theory of the Early Universe (Planck's scales) is applied to study a quantum theory of black holes. On this basis the author investigates the information paradox problem, entropy of the black hole remainders after evaporation, and consistency with the holographic principle. The possibi...

this study is focused on investigating the parameters of laser percussion drilling process of nickel-base super alloy inconel 718 with thickness of 1 mm. fiber laser with the power of 500 watts was used as the laser source. laser pulse frequency, duty cycle, laser power, focal point position, were assumed as the laser drilling process variables. the hole geometry features, i.e. entrance hole di...

Hybrid silicon nanocrystal (Si-NC)/poly(3-hexylthiophene) (P3HT) films serve as the active layers of quantum dot/polymer hybrid photovoltaics. To achieve effective photovoltaic properties, it is necessary to enhance the charge carrier mobility and carrier density of the P3HT films. A 50- and 12-fold enhancement of the hole mobility and hole density, respectively, was achieved along the out-of-p...