Fractioning of orange (Citrus sinensis L.) essential oil using vacuum fractional distillation

Citrus essential oil has many uses in food, cosmetics, and pharmaceuticals industries, especially the minor compounds present in the oil. This work aimed to evaluate the distillation patterns of the components of the peel essential oil of Citrus sinensis using vacuum fractional distillation. The performed tests show that the separation of the compounds occurs with the leaving of the lighter terpenes, followed by the heavier terpenes and part of the oxygenated functions. Most of the oxygenated functions remained in the bottom of the column, being concentrated in this fraction. Many trace compounds were found in the bottom products. The limonene mass percentage reduced from 96.68% to 52.81% in the bottom products. Linalool had its mass percentage increased from 0.37% in the raw oil to 4.22% in the bottom. It was also observed in the operation conditions of the column (10 kPa and 70°C), there was no evidence of thermal degradation of the raw oil, neither of the obtained fractions during the process.     

Sodium molybdate-hexagonal boron nitride composites enabled by cold sintering for microwave dielectric substrates

To fulfill the demands of more bandwidth in 5G and 6G communication technology, new dielectric substrates that can be co-fired into packages and devices that have low dielectric loss and improved thermal conductivity are desired. The motivation for this study is to design composites with low dielectric loss (tan δ) and high thermal conductivity (κ), while still limiting the electrical conductivity, for microwave applications involving high power and high frequency. This work describes the fabrication of high-density electroceramic composites with a model dielectric material for cold sintering, namely sodium molybdate (Na₂Mo₂O₇), and fillers with higher thermal conductivity such as hexagonal boron nitride. The physical properties of the composites were characterized as a function of filler vol.%, temperature, and frequency. Understanding the variation in measured properties is achieved through analyzing the respective transport mechanisms.     

Analysis of composite walls and their effects on short-pathpropagation modeling

For short-propagation paths, correctly representing reflections of electromagnetic energy from surfaces is critical for accurate signal-level predictions. In this paper, the method of homogenization is used to determine the effective material properties of composite materials commonly used in construction. The reflection coefficients for block walls and other types of materials calculated with these homogenized effective material properties are presented. The importance of accurately representing the reflections for signal-level prediction models is also investigated. It is shown that a 5-10-dB error in received signal strength (RSS) can occur if the composite walls are not handled appropriately. Such accurate predictions of signal propagation over a short distance is applicable to microcellular personal communications services deployments in urban canyons as well as indoor wireless private branch exchanges and local-area networks     

Radiation Pattern Synthesis for Broadcast Antennas

Two computer programs that can be used for the synthesis of radiation patterns of linear and planar arrays are described. The programs are listed in the Appendix and were written for the GE-645 computer, in Fortran IV language, and in a time-sharing mode.     

Noradrenergic receptor sensitivity in obsessive-compulsive disorders: I. Growth hormone response to clonidine stimulation

Dimeric anthracenones obtained from the genus Karwinskia (Rhamnaceae) are characteristic compounds isolated from the plants of this species. Previous toxicity studies demonstrated Diast T-514 to be toxic to animals in experimental settings. Diast T-514 extracted and characterized from Karwinskia parvifolia, was studied in CD1 mice. The LD50 for this compound was determined. Animals were tested with Diast T-514 following enteral and parenteral administration. An LD50 dose by both oral and intraperitoneal administration showed selective damage to target organs.     

Microdisplay‐based optical module for avionic display applications

Abstract— A new optical scheme for a LCOS‐based rear‐projection system utilizing an LED illumination source is presented. The proposed optical module could conveniently replace conventional aircraft panel instrumentation not only because it achieves major standard avionics application requirements, such as the capability to withstand mechanical shocks, high reliability, and weight and power‐consumption minimization, but also as a consequence of the fact that it allows the display image area to be properly matched to the shape of the instrument panel more easily than with conventional displays.