Optical one-dimensional waveguides in oxyfluoride glass fabricated by Helium Ion implantation

In this work, a one-dimensional waveguide is formed by virtue of the helium ion implantation in the oxyfluoride glass (OFG). The energy and the fluence of the ion implantation are 0.4 MeV and [Formula: see text] [Formula: see text], respectively. The m-line curve with the effective refractive indices of the modes was recorded by using the prism coupling system. The energy loss distribution and the refractive index profile were calculated by the stopping and range of ions into matter (SRIM)-2013 and the RCM, respectively. The light modal profile was measured by the end-facet coupling system. It suggests that the He[Formula: see text]-ion implanted OFG waveguides have the potential to act as integrated photonic devices.

Evaluation of Neoproterozoic Source Rock Potential in SE Pakistan and Adjacent Bikaner- Nagaur Basin India Based on Integrated Geochemical, Geological, and Geophysical Data

Discoveries of heavy crude oil in the Neoproterozoic rocks (Infracambrian rock sequence) from the Bikaner-Nagaur Basin of India emphasizes the significance to study and explore the Neoproterozoic source rocks potential in the southeastern part of Pakistan. This study evaluates the potential of the source rock in the Infracambrian rock sequence (Salt Range Formation) based on surface geochemical surveys, Rock-Eval pyrolysis, source biomarkers, geophysical characterization, and seismic inversion using machine learning for maturity index estimation. Core samples of Infracambrian rock were extracted for Rock-Eval pyrolysis and biomarker characterization. Also, 81 geo-microbial soil and gas samples were collected from the surface to explore the petroleum system and potential source rocks in the subsurface. We followed the standard laboratory procedures to investigate the origin and concentration of hydrocarbons gases at the surface, thermal maturity, the source facies, and the environment of deposition of organic matter. The results show that the investigated samples are characterized by restricted marine clay devoid of carbonate source facies with thermal maturity in the early-stage of the oil generation window. Surface geochemical samples also confirm higher concentrations of thermogenic C2-C4 hydrocarbons over the vicinity of anticlinal structures proving the existence of an effective migration path along deep-seated faults to the surface. The inverted maturity index profile demonstrates a reasonable correlation of thermal maturity with the surface geochemical survey, source biomarkers, and Rock-Eval pyrolysis. It validates the reliability of multilayer linear calculator and particle swarm optimization algorithms for inverting seismic reflection data into a maturity index profile. The obtained results indicate a higher probability of heavy and light oil along the eastern flank of Pakistan, where Infracambrian rocks are thicker and more thermally mature, and deep-seated pledged structural closures occur, in comparison to the Bikaner-Nagaur Basin, India.

Atherogenic Index Profile on Ischemic Stroke Patients at Neurology Department, Dr. Soetomo Surabaya: A Retrospective Study

Stroke was associated with morbidity and mortality in the world. Lipid index discovered through lipid profile tests may be used as a predictor in vascular diseases. To increase the prediction value of lipid profile to stroke outcome, several lipoprotein ratios, called atherogenic index, were still being researched. Atherogenic indexes included Atherogenic index of plasma, Castelli Risk Index I and II, atherogenic coefficient, and non-high density lipoprotein cholesterol. The aim of this study is to find atherogenic index profile as a marker for atherogenicity on acute ischemic stroke patients at Neurology Department Dr. Soetomo hospital from January-September 2019. This is a retrospective descriptive of 65 patients on stroke registry. Data collected including low and high AIP level on 19, 46 patients, respectively; low CRI I on 22 patients and high CRI I on 43 patients; low CRI II from 31 patients and high CRI II from 34 patients; low and high AC on 9 and 56 patients, respectively; also, low NHC on 21 patients and high NHC on 44 patients. Poor outcome on outpatient was identified in 30 patients (NIHSS >7). This study indicates most ischemic stroke patients have high atherogenic index level. Analysis on the differences between lipid index and NIHSS poor outcome revealed AC and NHC level were significant with p = 0,031, CI 8,593 (1,007 – 73,319) and p = 0,01, CI 9,529 (2,435 – 37,3), respectively. Keywords: atherogenic index, ischemic stroke, NIHSS.

Effect of Geometry on the Electromagnetic Wave Transport Properties of Photonic Crystals: Comparison of Top-Flat and Top-Curved Refractive Index Profiles

In the current paper, we try to engineer the refractive index profile in a one-dimensional photonic crystal as a powerful tool to manage the electromagnetic wave transmission properties. For this purpose, we have compared four sinusoidal, rectangular, triangular, and saw-tooth refractive index profile types. In this way, we have used a transfer matrix method accompanied by the discretization of the spatial domain. This method can readily be applied to any arbitrary continuous refractive index profile. Then, we have tried to address the effects of different geometrical and physical parameters, including the photonic crystal length L, dielectric permittivity εd, number of layers and plasma density np, etc. on the light propagation through the mentioned photonic crystals. In the proposed two-layer plasma/dielectric photonic crystals we could observe acceptable ranges of Omni-directional photonic band gaps that their position width and their number can be regulated. We determine the most and least tunable systems.

Passive discrete lens for broadband elastic guided wave focusing

Elastic guided wave focusing is of great interest for applications such as vibroacoustic control, energy harvesting, or Structural Health Monitoring. Different strategies allow generation of this effect, GRadient-INdex devices in particular exploit medium with varying properties such as thickness to reproduce an adequate refractive index profile as in optics. The resulting continuous profiles have a curved geometry that can be hard to manufacture, and be difficult to integrate in a given design. The purpose of this paper is to propose a discrete design for a GRIN lens. It is composed of segments selected in number and thickness to give similar focusing effects as a continuous lens profile. The identified configuration is manufactured and bounded on an aluminium plate to evaluate the effective focusing performances. Numerical and experimental vibrometry results confirm that the proposed lens exhibits a fixed focal point over a broad frequency range. The discrete design overcomes fabrication issues encountered in continuous design, allowing for an easier integration in devices for elastic wave control.