A 60‐GHz on‐chip slot‐array antenna in integrated‐passive‐device technology for antenna‐in‐package applications

A new millimeter‐wave antenna structure on a low‐cost, production platform integrated passive device technology is presented. The antenna consists of a 2‐by‐1 array of slot antennas at 60 GHz. An in‐house developed on‐chip antenna measurement setup was used to characterize the fabricated antenna. The measurement results show an antenna gain of more than 5 dBi with a return loss of 18 dB at 60 GHz. The better‐than‐10‐dB impedance bandwidth of the antenna covers the 60‐GHz unlicensed band from 57 to 64 GHz. The 3‐dB beamwidths of the antenna are 105° and 76° at E‐plane and H‐plane at 60 GHz, respectively. The size of the die of the antenna is 2 mm × 4.5 mm. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:155–160, 2014.     

Penetration Depth in Nanoparticles Incorporated Radiofrequency Hyperthermia into the Tissue: Comprehensive Study with Histology and Pathology Observations

In present study, the effective penetration of radiofrequency (RF) induced gold decorated iron oxide nanoparticles (GS@IONPs) hyperthermia was investigated. The effective penetration depth of RF also the damage potency of hyperthermia was evaluated during histopathology observations which were done on the chicken breast tissue and hepatocellular carcinoma (HCC) models. The thermal damages are well‐ documented in our previous cellular study which was engaged with potency of RF hyperthermia in Epithelial adenocarcinoma (MCF‐7) and fibroblast (L‐929) cells deaths [1]. In recent work, PEGylated iron oxide nanoparticles (IONPs) were used as base platform for gold magnetic nanoparticles (GS@IONPs) formation. The 144.00015 MHz, 180W RF generator was applied for stimulating the nanoparticles. The chicken breast tissue and the hepatocellular tumor model was considered in the experimental section. In histology studies, the structural changes also the effective penetration depth of RF induced nanoparticles was observed through microscopic monitoring of the tissue slices in histology observations (Gazi medical school). The highest damage level was seen in 8.0 µm tissue slices where lower damages were seen in depth of 1.0 cm and more inside tissue. The histology observations clarified the effective penetration depth of RF waves and irreversible damages in the 2.0 cm inside the tissue.Inspec keywords: nanomedicine, tumours, biomedical materials, cellular biophysics, nanoparticles, gold, cancer, hyperthermia, magnetic particles, iron compounds, radiation therapyOther keywords: Au‐Fe₃ O₄ , depth 1.0 cm, depth 8.0 mum, power 180.0 W, size 2.0 cm, frequency 144.00015 MHz, microscopic monitoring, structural changes, hepatocellular tumour model, standing wave ratio, propylene glycol, thermal damages, hepatocellular carcinoma models, radiofrequency hyperthermia, nanoparticle dispersion, tissue alterations, modified tissues, gold shell magnetic nanoparticles, chicken breast tissue, gold‐coated iron oxide nanoparticles, pathology observations, effective penetration depth, histology observations, tissue slices     

Biodiesel Production Using Calcined Waste Filter Press Cake from a Sugar Manufacturing Facility as a Highly Economic Catalyst

For the first time, a low cost, high performance and environmentally friendly heterogeneous catalyst derived from waste filter press cake (FPC) from a sugar manufacturing facility was used for the production of biodiesel. This industrial waste was calcined in air at 900 °C for 2 h to convert it into an active CaO‐based catalyst (FPC‐HT). In addition, the calcium oxide nanoparticles (FPC‐NAC) were synthesized by surfactant‐hydration treatment of FPC‐HT. The synthesized catalysts were characterized by XRD, FTIR, SEM, TEM and BET analysis. These calcium oxide catalysts were used for a transesterification reaction between canola oil and methanol to produce biodiesel. The results show that the FPC‐NAC has higher catalytic activity than FPC‐HT under optimized reaction conditions. Therefore, this economic catalyst is able to catalyze the transesterification of canola oil to its methyl esters in 1.5 h with yields above 96 %.     

A bending theory for beams with vertical edge crack

In this paper a linear continuous theory for bending analysis of beams with an edge crack perpendicular to the neutral plane subject to bending has been developed. The model assumes that the displacement field is a superposition of the classical Euler-Bernoulli beam's displacement and of a displacement due to the crack. It is assumed that in bending the additional displacement due to crack decreases exponentially with distance from the crack tip. The strain and stress fields have been calculated using this displacement field and the bending equation has been obtained using equilibrium equations. Using a fracture mechanics approach the exponential decay rate has been calculated. There is a good agreement between the analytical results from solving the differential equation of cracked beam and those obtained by finite element method.     

A Fully Integrated 2 $,times,$2 Power Amplifier for Dual Band MIMO 802.11n WLAN Application Using SiGe HBT Technology

A fully monolithic 2 times 2(2 times 5 GHz-band, 2 times 2.4 GHz-band) power amplifier (PA) implemented in a 0.18 mum Silicon Germanium (SiGe) HBT process has been developed for a dual band MIMO 802.11n WLAN system. In order to achieve the required performance for the 5 GHz band while maintaining a high level of integration, different approaches have been investigated. A special Through-Wafer-Via (TWV) process on Si wafer was developed and utilized for this 2 times 2 PA. From fabricated 2 times 2 chip measurement results, both 5 GHz-band and 2.4 GHz-band PAs show above 17 dBm linear power output for -28 dB EVM and more than 18 dBm with >14% efficiency for 5 GHz-band and 19% efficiency for 2.4 GHz-band at -25 dB EVM linear output.     

Optimal sensor array configuration in remote image formation.

Determination of optimal sensor configuration is an important issue in many remote imaging modalities, such as tomographic and interferometric imaging. In this paper, a statistical optimality criterion is defined and a search is performed over the space of candidate sensor locations to determine the configuration that optimizes the criterion over all candidates. To make the search process computationally feasible, a modified version of a previously proposed suboptimal backward greedy algorithm is used. A statistical framework is developed which allows for inclusion of several widely used image constraints. Computational complexity of the proposed algorithm is discussed and a fast implementation is described. Furthermore, upper bounds on the sum of the squared error of the proposed algorithm are derived. Connections of the method to the deterministic backward greedy algorithm for the subset selection problem are presented, and two application examples are described. Five compelling optimality criteria are considered, and their performance is investigated through numerical experiments for a tomographic imaging scenario. In all cases, it is verified that the configuration designed by the proposed algorithm performs better than wisely chosen alternatives.     

Nanoethosomal formulation of gammaoryzanol for skin-aging protection and wrinkle improvement: a histopathological study

Background: Free radical scavengers and antioxidants, with the main focus on enhanced targeting to the skin layers, can provide protection against skin ageing.

Objective: The aim of the present study was to prepare nanoethosomal formulation of gammaoryzanol (GO), a water insoluble antioxidant, for its dermal delivery to prevent skin aging.

Methods: Nanoethosomal formulation was prepared by a modified ethanol injection method and characterized by using laser light scattering, scanning electronic microscope (SEM) and X-ray diffraction (XRD) techniques. The effects of formulation parameters on nanoparticle size, encapsulation efficiency percent (EE%) and loading capacity percent (LC%) were investigated. Antioxidant activity of GO-loaded formulation was investigated in vitro using normal African green monkey kidney fibroblast cells (Vero). The effect of control and GO-loaded nanoethosomal formulation on superoxide dismutase (SOD) and malondialdehyde (MDA) content of rat skin was also probed. Furthermore, the effect of GO-loaded nanoethosomes on skin wrinkle improvement was studied by dermoscopic and histological examination on healthy humans and UV-irradiated rats, respectively.

Results: The optimized nanoethosomal formulation showed promising characteristics including narrow size distribution 0.17?±?0.02, mean diameter of 98.9?±?0.05?nm, EE% of 97.12?±?3.62%, LC% of 13.87?±?1.36% and zeta potential value of –15.1?±?0.9?mV. The XRD results confirmed uniform drug dispersion in the nanoethosomes structure. In vitro and in vivo antioxidant studies confirmed the superior antioxidant effect of GO-loaded nanoethosomal formulation compared with control groups (blank nanoethosomes and GO suspension).

Conclusions: Nanoethosomes was a promising carrier for dermal delivery of GO and consequently had superior anti-aging effect.     

A Variable Current-Limit Control Scheme for a Bi-directional Converter used in Ultracapacitor Applications

In ultracapacitor applications, generally, a bi-directional converter is connected to a DC bus and is designed to compensate rapid load variations on the bus. During transient phases, overloaded DC bus can push the converter out of its operating limits. For providing the necessary power, converters should be put in parallel, while each converter is limited into its optimal operating range. In a boost converter, this operating limit can be related to the inductor current and UC voltage. In this study, a variable current-limit is proposed for inductor current which then determines the operating range of the boost converter. This method will provide stability of the converter during overload transients. An experimental setup consisting of a bi-directional converter, a controllable load/source, and an ultracapacitor is presented, to validate the proposed method. Several scenarii are applied to analyze the performance of the system in overloaded phases and theoretical and experimental results are presented.