Investigation of Crosstalk and Coupling Effects of Incident Plane Waves in Orthogonal Microstrips in High-Speed Integrated Circuits Using Full-Wave and Quasi-Static Methods

The crosstalk and coupling of the external fields on orthogonal microstrip transmission lines in different layers have significant effects on signal quality in MMIC and PCBs. In this paper the crosstalk is analyzed in detail using both full-wave and quasi-static methods. The used full wave method is mixed potential integral equation method of moment (MPIEMoM). Because of the weak coupling between lines, the effect of the incident plane-wave is studied by applying transmission line theory in a scattered voltage formulation uses quasi-TEM propagation model for each interconnection and the exact distribution of the incident electric field within the layers. Afterward, by using the predetermined lumped circuit model of the cross-region, the effect of coupling between two lines is calculated and then applied to terminal voltages in 1–20 GHz frequency range which results in the final terminal voltages.     

Surface and structure characteristics of commercial K-Feldspar powders: Effects of temperature and leaching media

This study presents morphological and structural variations of K-Feldspar mineral after acid treatment. Both organic and inorganic acids such as C₂H₂O₄, HCl, HNO₃ and H₂SO₄ were employed for this purpose. Another aim of this study was to find an optimum experimental condition for iron (Fe) removal with a minimum damage on the structure of K-Feldspar in which high whiteness index is obtained. The effect of different parameters such as concentration, pH and temperature on the final structure of this mineral was investigated. To find out the chemical composition of powder, XRF was utilized. FTIR, XRD and SEM were employed to study the structure of mineral. Spectrophotometry was chosen to analyze whiteness index of powder after acid treatment. It was found that O—Al—O bond at 647 cm^-1 for H₂SO₄ and HNO₃ treated sample disappeared. However, HCl and C₂H₂O₄ were ineffective at this band. In addition, the results revealed an increase in K-Feldspar content, a decrease in Fe content, an increase in whiteness index and no significant structural change for C₂H₂O₄ leached sample. Whiteness index of 91% was obtained for C₂H₂O₄ leached sample with the pH of 2.5 to 3 at temperature of 50℃ and during 1 h.     

Effect of annealing treatment on optical properties and microstructural variation of $$\hbox {WO}_{3}/\hbox {Ag}/\hbox {WO}_{3}$$ multilayer nano-films

Structural and optical properties of \(\text {WO}_{3}/\text {Ag}/\text {WO}_{3}\) nano-multilayer composites were investigated for heat mirror applications. \(\text {WO}_{3}/\text {Ag}/\text {WO}_{3}\) thin films were fabricated through a physical vapour deposition method by using electron-beam evaporation at the vacuum chamber at 10\(^{-5}\) Torr. \(\text {WO}_{3}\) nano-layer was fabricated at 40 nm. Annealing treatment was carried out at 100, 200, 300 and 400\(^{\circ }\)C for 1 h after the deposition of first layer of \(\text {WO}_{3}\) on the glass. On \(\text {WO}_{3}\) film, Ag nano-layers with 10, 12 or 14 nm thickness were deposited. Individual layers morphology was investigated using atomic force microscopy (AFM) and deduced that a smoother layer can be achieved after the annealing at 300\(^{\circ }\)C. Ellipsometry analysis was executed to determine both layers, Ag film thickness and inter-diffusion between the \(\text {WO}_{3}\)–Ag–\(\text {WO}_{3}\) layers. It was inferred that there was almost no interfering among the \(\text {WO}_{3}\)–\(\text {WO}_{3 }\) layers in the samples with 12 and 14 nm Ag thickness; while silver was deposited on the annealed \(\text {WO}_{3}\) layer at 300\(^{\circ }\)C. UV–visible spectrophotometer showed that the annealing treatment of the first \(\text {WO}_{3}\) layer enhanced the transparency of films in the visible region. The innovations of the present study have been based on the annealing of the films and finding an optimum thickness for the Ag film at 12–14 nm. Heat mirrors efficiency was assessed according to the principle of their optical behaviour and optimum performance obtained for 14 nm of Ag film, deposited on annealed tungsten oxide at 300\(^{\circ }\)C.     

A multi-period scheduling method for trading-off between skilled-workers allocation and outsource service usage in dynamic CMS

In this paper, a new method is proposed for short-term period scheduling of dynamic cellular manufacturing systems in a dual resource constrained environment. The aim of this method is to find best production strategy of in-house manufacturing using worker assignment (both temporary and skilled workers) and outsourcing, while part demands are uncertain and can be varied periodically. For this purpose, a multi-period scheduling model has been proposed which is flexible enough to use in real industries. To solve the proposed problem, a number of metaheuristics are developed including Branch and Bound; a hybrid Tabu Search and Simulated Annealing algorithms and a hybrid Ant Colony Optimization and Simulated Annealing algorithms. A Taguchi method (L₂₇ orthogonal optimisation) is used to estimate parameters of the proposed method in order to solve experiments derived from the literature. For evaluating the system imbalance in dynamic market demands, a new measuring index is developed. Our findings indicate that the uncertain market demands affects the part allocating which may induce workstation-load variations that yield to cell-load variation accordingly. To solve this problem, two methods are offered. The results show that promoting staff and using freezing technique are promising ways to reduce system imbalance while confronting with the mentioned condition. The outcomes also show the superiority of the proposed hybrid method in providing solutions with better quality.     

Boehmite nanopetals self assembled to form rosette-like nanostructures

Rosette-like boehmite nanostructures were prepared successfully via a simple hydrothermal process. The obtained material was characterized with X-ray powder diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Using Scherrer formula, the average crystallite size of the obtained boehmite rosettes was measured to be about 8 nm. It was shown that boehmite nanopetals with average width of about 41 nm determined by TEM, were formed during the hydrothermal process and then self assembled due to weak hydrogen bonds to fabricate boehmite rosettes. The specific surface area of the obtained rosette-like nanostructures was calculated through BET N₂-adsorption technique to be about 143.08 m²/g.     

对明串珠菌及其他细菌的抑制效果

在从压榨间直到蔗汁澄清的蔗糖生产过程中,蔗汁中微生物活动是破坏蔗糖品质的一个重要因素。蔗糖损失和葡聚糖的形成通常与蔗汁中微生物引起的变质有关。多年来,这一直成为糖厂试图改善蔗糖品质时所面临的问题。本文以直接影响得糖率的微生物减少和相对纯度为指标,研究了不同杀菌方法在蔗汁中的效果。浓度为0.007%的S抑制剂显示了对某糖厂初压汁和混合汁中的微生物菌群的抗菌效应。在对照组中,12h后观察到4.8单位的纯度降低。加入S抑制剂后,只降低2个单位。且蔗汁的稳定性在3个样品中几乎完全一致。以S抑制剂处理的蔗汁保持深褐色和清新的气味,且pH与初始相比无显著变化,而未处理的蔗汁变浅褐色,产生很强的酒味,pH和纯度显著降低。这种稳定效应尚未被其他常用的糖用杀菌剂所报导。同样,本文证明了有可能通过使用S抑制剂来稳定混合汁。经S抑制剂处理后,游离的还原物质和多聚糖比不经处理的样品低6倍。这些结果表明,形成的葡聚糖以及随之形成的游离果糖减少。     

Unraveling Recrystallization Mechanisms Governing Texture Development from Rare-Earth Element Additions to Magnesium

Metallurgical and Materials Transactions A - The origin of texture components often associated with rare-earth element (REE) additions in wrought magnesium alloys is a long-standing problem in...     

Effect of Joint Geometry on the Behavior and Failure Modes of Sandwich T-Joints Under Transverse Static and Dynamic Loads

Due to wide spread application of adhesive T-joints in various industries, a review of properties and strength of their fracture modes under static and dynamic loadings is required. By defining the ability of failure in the joint material and fracture of adhesive in the numerical model, fracture modes of sandwich T-joints have been investigated. This paper presents numerical results on the performance of sandwich T-joints subjected to static tensile, static transverse, and dynamic transverse loading. The results of available experiments in the literature have been used to validate the detailed numerical models capable of simulating the damage processes observed. In general, the failure load predicted by the finite element (FE) analysis is within 5% of the experimental results.     

Cooperative network solution and implementation for emergency applications with enhanced position estimation capability

This paper proposes a cooperative network topology for emergency applications which comprises of incident scene networks (ISN) and external area networks. Both base stations and rescuers in ISN are modeled as nodes with the capabilities of software defined radio and signal processing. A worldwide interoperability for microwave access-based emergency protocol is proposed with which rescuers can estimate their geo-locations via time difference of arrival based on more than four known base stations coordinates. A comparative study of state-of-the-art position estimation methods have been carried out for the proposed cooperative network topology to select the most robust method. Hardware results for the most robust position estimation method without/with multipath mitigation have been implemented and presented to estimate the location of the rescuer.