The Effect of Shear Wall Openings on the Response Reduction Factor

This research attempts to investigate the effect of shear wall openings on the response reduction factor. Openings are commonly necessary because of other engineering disciplines’ requirements. When openings are modest in proportion to the size of the wall, their effects are frequently disregarded. On the other hand, when these openings are large or located in a high-risk area, they can have a significant impact. A broad literature review has been conducted in the present study. A verified comparative example consisting of eight stories was studied. Then, a numerical study has been conducted on two different model sets with 16 and 8 stories, which were designed according to the Egyptian code of loads, ECP-201 (2012), and checked according to the Euro code, EC8 (2004). ETABS software was used to conduct pushover analysis before and after applying different-sized openings. The ground-opening effect has also been studied. The results show that by increasing the opening area, the R-factor was reduced. It is more influenced by the opening height than the width, though. By increasing the number of stories, the reduction percentage in the R-Factor increased for openings that are less than 30% of the wall area. The R-factor increases slightly when half of the reinforcement bars are added. Doi: 10.28991/CEJ-2022-08-04-013 Full Text: PD

A User-Centred Approach Exploring the Potential of a Novel EMG Switch for Control of Assistive Technology

This study examines the potential application of an EMG technology as an assistive control method for individuals with severe physical disabilities. The usability and acceptability of a prototype EMG switch was evaluated with health care professionals, researchers and end users using participatory approaches

Response Reduction Factor for Structures with Significant Irregularities on Different Soil Stratum

The ability of a structure to dissipate energy through inelastic behavior is reflected in the response reduction factor (R), which is influenced by redundancy, ductility, and overstrength. Accurate determination of R is crucial for seismic design. This study focuses on determining the response factor for reinforced concrete (RC) structures with various irregularities. Non-linear static pushover analysis using SAP2000 was employed for numerical simulations to assess the impact of soil-structure interaction (SSI). The analysis included elevational and in-plan irregularities, revealing that buildings with irregular vertical geometries have lower inelastic seismic capacities compared to regular buildings. Consequently, R should be reduced by 15–40% from the ECP 2020 standard before the design phase for such structures. Irregularity was found to have a significant impact on weak soil conditions (C), leading to a reduction in R of 20.3% and 13.1% for fixed and isolated supports, respectively, on loose soil. Additionally, stiffer base soils were associated with higher R values for the same structure. Doi: 10.28991/CEJ-2024-010-03-07 Full Text: PD

Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries

© 2018 Elsevier Ltd MnF2 infiltrated-CNT fabrics was prepared by surfactant-aided impregnation of MnSiF6 precursors in acid-treated CNT fabric followed by annealing MnSiF6-loaded CNT fabric. The structural and morphological characterizations by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the formation of MnF2 nanoparticles (average size: 20–30 nm) within CNT fabric structure. Galvanostatic charge-discharge tests of CNT-MnF2 nanocomposite fabrics showed excellent electrochemical performance and good cycle stability between 0.4 and 4.0 V vs Li/Li+. A specific capacity of 388 mAh/g was measured at 0.1C for CNT-MnF2 fabric with 70% MnF2 loading after 100 cycles. Stable cyclability and good rate performance were obtained at high charge-discharge cycling rates. MnF2 loading largely affect the performance of MnF2 infiltrated-CNT fabrics cathodes when lower than 70% MnF2 loaded-CNT fabrics were prepared. It can be concluded that nano-sized active materials infiltrated inside conductive carbon matrix in optimized content can lead to rapid kinetics and stable performance for flexible metal fluoride-based cathode materials.This work was funded by a grant from the Qatar National Research Fund under its National Priorities Research Program award number NPRP7-567-2-216 . Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Qatar National Research Fund . The authors are thankful to Prof Gleb Yushin from Georgia Institute of Technology for his collaboration in this subject

Serological, hematological, Biochemical and Oxidative Markers During Foot and Mouth Disease Serotype ‘O’ Infection, Egypt

Foot and mouth disease (FMD) is an extremely grave communicable disease of livestock. It affects all wild and domestic animals with cloven hoof. It is caused by Aphtho virus (Apthous fever) or (FMDV) foot and mouth disease virus which is originated from family Picornaviridae. 30 adult female water buffaloes, 3-5 years old infected with FMD serotypes, O. These animals were located at Sharkia governorate, Egypt during the period beetwen December 2014 to March 2015. Hematological findings showed no significant change in erythrogram and reduction in total leukocytes in the early stage of FMDV infection. Moreover development of macrocytic normochromic anemia and increase in total leukocytes and lymphocytic counts was reported in the late stage of infection. A significant decrease in cholesterol , progesterone , total proteins, albumin , globulins, calcium and sodium levels in infected groups, while a significant increase in serum activities of ALT ,AST, glucose, total, direct ,indirect bilirubine, phosphorous potassium, NO. MDA, CK-MB, LDH and CTNI. Without alterations in creatinine level

Isolation and characterization of antineoplastic alkaloids from Catharanthus roseus l. Don. cultivated in Egypt

Vinblastine and vincristine (the antileukemic agents) were isolated, in a pure form, from Catharanthus roseus L. Don., cultivated in Egypt, by several chromatographic techniques. Five modified methods for the preparation of total alkaloids were carried out. All the isolated mixtures were evaluated by HPLC and HPTLC analyses. The antineoplastic alkaloids; vinblastine and vincristine, were isolated by the use of vacuum liquid chromatographic column on silica gel : aluminium oxide (1:1) mixed bed vacuum liquid chromatography (VLC), Charcoal column, and finally purified by centrifugally accelerated radial chromatography (Chromatotrone).Key words: Catharanthus roseus L., Apocyanaceae, Vinblastine, Vincrisitine, Antileuckemic alkaloids, VLC, HPLC, HPTL

MICROWAVE-ASSISTED EXTRACTION OF BIO-ACTIVE COMPOUNDS (PHENOLICS AND ALKAMIDES) FROM ECHINACEA PURPUREA

Objective: Echinacea purpurea is used widely for its unspecific enhancement of the immune system. It contains multiple bioactive substances, including, phenolics (caffeic acid derivatives), flavonoids, anthocyanins and alkamides. In this currently investigation, efforts are focused on the evaluation of extraction techniques viz., conventional extraction (CE) and microwave-assisted extraction (MAE) for the regeneration of the active constituents of Echinacea purpurea. Methods: The aerial parts have been separately extracted with 80% methanol by two methods; CE and MAE. Identification of the isolated compounds was carried out by spectroscopic analysis viz., UV, TLC, 1H- NMR and MS. TLC scanner system and RP-HPLC with UV detection have been employed for the quantitative determination of caffeic acid derivatives and that of alkamides content in both extracts. Results: Chicoric and caftaric acids have been isolated and identified. The results of the TLC scanner system have revealed that the concentration is about 1.19 ± 0.02 and 1.35 ± 0.03 % (w/w) for caftaric and chicoric acid, respectively of the dry plant material extracted with CE, while the concentration is 1.81 ± 0.04 and 6.19 ± 0.26 % (w/w) for the two acids, respectively of the dry plant material extracted by MAE. The results of the HPLC have revealed that the concentration of alkamides is 0.25 and 0.33 % (w/w) of the dry plant material obtained with CE and MAE, respectively. Conclusion: Our study proved that MAE is a more effective technique compared to the CE. Extraction time was reduced, with the use of less solvent and the yield amount of the extracted active compounds was increased

Heat and freezing pre-thermal treatments as a means of freeing potatoes from mosaic virus and its effects on potato plants quality characters

The aim of the study was to control of potato mosaic virus by using hot-air, hot-water and freezing as a physical pre-thermal treatments. Infected tubers of Lady Rosetta and Mondial potato (Solanum tuberosum L.) cultivars were treated by hot-air and hot-water treatments at 55± 2 ̊ C and freezing treatment at -18±2 ̊ C for 1, 2, 3 and 4 hours.  Hot-air and freezing treatments showed complete elimination of mosaic virus from treated tubers. Hot-water treatment caused tuber damage at different exposure times. In this respect, hot-air treatment at 55± 2 ̊ C and freezing treatment at -18±2 ̊ C for two hours gave the best results of eliminating the virus from tubers and did not affect on economic characters of potato cultivars.