Preparation ,Characterization and Thermal Properties of New Aromatic Polyester Based on Di ,Tri and Tetra Hydroxyl Monomers with 4,4Azo Di Benzoic Acid and Adipic Acid

A series of new aromatic Polyesters were  synthesized by  polycondensation of various aromatic monomers  di ,tri and tetra diols (BCAHPMNM , BHPMB, BHPPB , BPBHP) with Acids(4,4Azo Di benzoic acid  and Adipic acid) using  dibutyltine dilaurate as Catalyst .all polyesters(P.E1-P.E4)containing pyridine heterocyclic group, aliphatic methylene linkage, and Azo group. The yield of Polyesters varies from 60-85%. All of  these  new  aromatic polyester  show very good  solubility in common organic  solvents , such as (pyridine , CHCl3 ,  CH2Cl2 , NaOH , H2SO4 , HNO3 , Acetone , Benzene ,  DMF , DMSO , THF) without need for heating. Thermal analysis of polyesters by thermo gravimetric analysis (TGA) reveals that these Aromatic polyesters possess thermal stability. Monomers and polyesters characterized by FT-IRand1HNMRspectrosticcopy. Keywords: Aromatic polyester , 4,4Azo Di benzoic acid  , Adipic acid,  dibutyltine dilaurate

Studying the Effect of Glass - Fiber on Electrical Conductivity of Polyamide Composite Material

The electrical conductivity of glass fibre reinforced polyamide composite materials was investigated for both weight fraction of glass fibre and frequency. This study is focused on various types of glass fibres (S, E&C) and different weight fractions (10, 20, 30 &40) at frequencies (50, 500, 1000, 105 &106) Hz. The results exhibited addition glass fibre fillers on matrix material were apparent good electrical conductivity at high weight fraction comparing to their low percentage account of the fillers created conductive path in the matrix material, it reached to (2.52, 2.1&2.21)* 10-10 S/cm for C-glass fiber, E-glass fiber and S-glass fiber; respectively at %40 weight fraction. Also that electrical conductivity increased with increasing in frequency due to charges movement in the dielectric material

Studying the Effect of Chemical Solution on Corrosion Behavior of SiC and Al2O3 Reinforced Aluminum Composite Materials

Corrosion behavior of aluminum matrix composites (MMCs) with (10, 20 &30) weight fraction of each alumina and silicon carbide was investigated in 10% (NaCl, NaOH &HCl) solutions at different temperatures (40, 60, 80 &100) °C also at room temperature. The results showed the corrosion rate was increased with increasing in weight fraction of alumina and silica as reinforcement due to discontinues protective film in addition to increasing in temperatures at 10 % HCl solution, it reached (8.252 mpy) by reinforced with SiC. Alumina was exhibited corrosion resistant better than SiC due to it is insulator; galvanic corrosion occurs when incorporation of semiconductor SiC only. Specimens were exposed to NaOH solution, aluminum reinforced with Al2O3 and SiC appears poor corrosion resistance. Finally, the results of effect NaCl were investigated, appeared an increase in corrosion rate with increasing in time

Studying The Effect of Copper And Zinc Ions on The Corrosion Rate of Carbon Steel

An experimental work was performed to study the effect of Zn, Cu ions onthe corrosion rate of carbon steel in distilled and tap water solution containing, 25& 50 ppm concentration of Zn, Cu ions at pH range 4, 6 &8 in distilled water andat pH8 in tap water at room temperature under both static for 10 weeks and 1, 2,6 &12 hours with dynamic conditions. The obtained results showed that thecorrosion rate was increased in the presence of 50 ppm of Cu ions in tap water(2.326 mpy) after 10 weeks, under static conditions, whereas under dynamicconditions, it was reached (10.511 mpy), the presence of fine suspended solidparticles in the solutions may also cause an increase in corrosion rate due to theirmovement over the carbon steel surface .In contrast, the presence Zn ions insolution as sacrificial anode, therefore, the corrosion rate was 2.24 times less thanthat in presence of Cu ions, at the same conditions. In distilled water, thecorrosion rates were decreasing slightly with adding Zinc and copper ionscomparing to absence of metals ions in solution except at pH4 in the presence50ppm of Cu ions may be accounted due to the increasing in the conductivity ofthe solution, under static conditions. At 25ppm of Zn ions lowering in corrosionrate may be explained that the Zn ions were protected carbon steel surface bysacrificial. In the absence of Zn, Cu ions were also carried out

Studying the Effect of Chemical Solutions on Bending Behavior of Epoxy Reinforced With CDs Waste

The aim of this study is the effect of salt, acid and base solutions on bending behavior of CDs reinforced epoxy. Epoxy resin matrix is reinforced with weight fraction 15, 30&45 % chopped chips CDs waste. The experimental results indicate that the composites materials have higher flexural stiffness than the matrix material where the young modulus of epoxy is improved from 2.6GPa for matrix to 3.936 GPa reinforced with 45% CDs that is 60% increasing, due to CDs were more contact which have high flexural stiffness. The test solutions chosen were 10 % NaCl, NaOH & H2SO4. The results indicate that the 45% CDs reinforced epoxy chosen is good chemical resistant to NaCl and NaOH whereas flexural stiffness changes are relatively for each examination time, while the maximum flexural stiffness occurred in H2SO4 solution was approximately -10% for 8 week due to epoxy is less resistant to sulfuric acid

Studying the Effect of Water on Electrical Conductivity of Cu Powder Reinforced Epoxy Composite Material

We study electrical conductivity behavior of Cu-powder reinforced epoxy composite material in different solutions (distilled water, tap water &3.5%NaCl) with a weight fraction (5, 15, 30 &45) was investigated for (7) weeks immersion time. The results exhibit that electrical conductivity increases as increasing immersion time due to the specimen was absorbed the solutions. The maximum values were reached with 3.5% NaCl solution because of Cl ions whereas electrical conductivity not apparent in distilled water was attributed to pure water containing no ions is an excellent insulator

ReDeCheck: An Automatic Layout Failure Checking Tool for Responsively Designed Web Pages

Since people frequently access websites with a wide variety of devices (e.g., mobile phones, laptops, and desktops), developers need frameworks and tools for creating layouts that are useful at many viewport widths. While responsive web design (RWD) principles and frameworks facilitate the development of such sites, there is a lack of tools supporting the detection of failures in their layout. Since the quality assurance process for responsively designed websites is often manual, time-consuming, and error-prone, this paper presents ReDeCheck, an automated layout checking tool that alerts developers to both potential unintended regressions in responsive layout and common types of layout failure. In addition to summarizing ReDeCheck’s benefits, this paper explores two different usage scenarios for this tool that is publicly available on GitHub

XFix: An Automated Tool for the Repair of Layout Cross Browser Issues

Differences in the rendering of a website across different browsers can cause inconsistencies in its appearance and usability, resulting in Layout Cross Browser Issues (XBIs). Such XBIs can negatively impact the functionality of a website as well as users’ impressions of its trustworthiness and reliability. Existing techniques can only detect XBIs, and therefore require developers to manually perform the labor intensive task of repair. In this demo paper we introduce our tool, XFix, that automatically repairs layout XBIs in web applications. To the best of our knowledge, XFix is the first automated technique for generating XBI repairs

Automated Repair of Layout Cross Browser Issues Using Search-Based Techniques

A consistent cross-browser user experience is crucial for the success of a website. Layout Cross Browser Issues (XBIs) can severely undermine a website’s success by causing web pages to render incorrectly in certain browsers, thereby negatively impacting users’ impression of the quality and services that the web page delivers. Existing Cross Browser Testing (XBT) techniques can only detect XBIs in websites. Repairing them is, hitherto, a manual task that is labor intensive and requires significant expertise. Addressing this concern, our paper proposes a technique for automatically repairing layout XBIs in websites using guided search-based techniques. Our empirical evaluation showed that our approach was able to successfully fix 86% of layout XBIs reported for 15 different web pages studied, thereby improving their cross-browser consistency

Studying the Effect of Aluminum Powder Addition on Dielectric Behavior of Polyester Composite Materials

The effect of both weight fraction of aluminium and frequency on dielectric properties of Al- powder reinforced polyester composite materials were investigated. We study the dielectric behaviour of composite materials reinforced with (0, 5, 15, 30 &45) weight fraction of Al and frequency ranges (50-106) Hz at room temperature. The results show the dielectric constant and dielectric losses factor were increased with increasing in weight fraction of aluminium due to high conductivity of aluminium. The decrease in the dielectric constant and dielectric losses with higher frequencies can be explained by the fact that as the frequency increases, the interfacial dipoles have less time to orient themselves in the direction of the alternating field