Frequency

A rigorous electromagnetic theory is suggested to analyze multiport waveguide junctions with artificial discontinuities formed of inductive strips and diaphragms. This theory is based on the original theories of waveguide junctions [1-2] and strip gratings [3] to properly take account of edge condition nearby the strip edges. The characteristics of these junctions in a broad parameter range are presented, and their reflective and matching properties are demonstrated.

Offset‐dependent attributes—amplitude versus offset (AVO) and frequency versus offset—are extracted from 2‐D P‐wave seismic data using the multiple signal classification technique. These attributes are used to detect fracture orientation in a carbonate reservoir located in the Maporal field in the Barinas basin of southwestern Venezuela. In the fracture normal direction, P‐wave reflectivity is characterized by a large increase of amplitude with offset (large positive AVO gradient) and a large decrease of frequency with offset (large negative frequency versus offset gradient). In the fracture strike direction, P‐wave reflectivity shows a scattered variation in AVO but a small variation in frequency with offset. Our results also show that the reservoir heterogeneity can lead to large variations of AVO signatures and that using azimuthal offset‐dependent frequency attributes can help lessen the ambiguity when detecting fracture orientation.

In this paper, we describe the design of an electrically large anechoic chamber for usage on millimetre-wave bands. Ansys Savant sotware was used to perform a simulation of the chamber, using physical optics coupled with uniform theory of diffraction (PO/UTD). Moreover, a method based on an open waveguide probe is described in this paper to obtain the electrical properties of the RF absorbers at millimetre-wave frequencies. Two different source antennas were simulated in this work and the corresponding quiet zones predicted. The largest quiet zone was 30 m m × 30 m m × 50 m m , for a chamber size of 1.2 m m × 0.6 m m × 0.6 m .

In this study, we focus on the retrieval of liquid and ice-phase cloud microphysics from spaceborne and ground-based lidar-cloud radar synergy. As an application of the cloud retrieval algorithm developed for the EarthCARE satellite mission (JAXA-ESA) [1], the derived statistics of cloud microphysical properties in high latitudes and their relation to the Arctic climate are investigated.

Abstract-An experimental investigation of a rectangular microstrip patch structure having an inset or recessed feed at its non-radiating edge is presented. The basic structure operates at 1.6 GHz, when fed with a coaxial line or microstrip side feed line. However, the inset fed ...

The aim of present study was to determine the prevalence rate of Human Immunodeficiency Virus (HIV) co-infection in HBV and HCV positive patients. It was also done in order to determine the risk factors of HBV and HCV transmission in Lorestan province. In this cross-sectional study (September 2014 to September of 2016), after presenting full details to patients, their written consent was obtained, and at the next stage, they were referred to high-risk behavior counseling centers in the city. The centers tried to collect demographic and epidemiological information and to determine possible ways of transmission for each patient. Then, the patients were referred to the pathobiology labs throughout the city to conduct laboratory supplementary studies. Finally, the obtained findings were analyzed using SPSS software and P<0.05 was set as the significant level of differences.Out of a total of 373 patients in this study, 252 of them (67.56%) were male and 121 (32.44%) were female. In th...

An improved model for the microwave brightness temperature seen from space over calm ocean is presented. This model can be divided into two sub-models, the atmospheric absorption model and the ocean surface emissivity model. An improved model for the absorption of the atmosphere near the 22 GHz water vapor line is

Chemically propelled micropumps are promising wireless systems to autonomously drive fluid flows for many applications. However, many of these systems are activated by nocuous chemical fuels, cannot operate at high salt concentrations, or have difficulty for controlling flow directionality. In this work we report on a self-driven polymer micropump fueled by salt which can trigger both radial and unidirectional fluid flows. The micropump is based on the cation-exchanger Nafion, which produces chemical gradients and local electric fields capable to trigger interfacial electroosmotic flows. Unidirectional pumping is predicted by simulations and achieved experimentally by nanostructuring Nafion into microarrays with a fine tune modulation of surrounding surface zeta potentials. Nafion micropumps work in a wide range of salt concentrations, are reusable, and can be fueled by different salt cations. We demonstrate that they work with the common water-contaminant cadmium, using the own cap...