Synthesis, cytotoxicity and bioimaging of a novel Hg2+ selective fluorogenic chemosensor

Saleem, M.,Abdullah, R.,Ali, A.,Park, B.,Choi, E.,Hong, I.,Lee, K. Royal Society of Chemistry 2014 Analytical methods Vol.6 No.11

A rhodamine B derivative 2 with a terminal mercapto thiadiazole moiety was successfully synthesized and applied for selective recognition of Hg2+ in aqueous-acetonitrile (1:1, v/v, pH 7) solution by employing its photophysical properties. Low toxicity and precise cell-permeability of the ligand were used to probe in vitro intracellular mercury contamination using L-929 cells (mouse fibroblast cells) and BHK-21 (hamster kidney fibroblast) through a confocal fluorescence microscopic experiment and bio-imaging results showed the equal applicability of the ligand toward both tested cell tines. Meanwhile, it exhibited distinct Hg2+ induced increment in the fluorescence and absorption intensities with induction of an apparent colorimetric change from colorless to reddish pink, providing naked eye mercury detection based on the metal-promoted intramolecular electronic rearrangement in the probe molecule. The probe responds selectively to Hg2+ over various competitive cations (Sc3+, Yb3+, In3+, Ce3+, Sm3+, Cr3+, Sn2+, Pb2+, Fe2+, Ni2+, Co2+, Cu2+, Ba2+, Ca2+, Mg2+, Ag+, Cs+, Cu+, and K+) with marked fluorogenic response and selective colorimetric changes with high sensitivity of 30 nM. We expect that the proposed method will serve as a practical tool for environmental sample analysis and biological studies.

A strain-based wire breakage identification algorithm for unbonded PT tendons

A.B.M. Abdullah,Jennifer A. Rice,H.R. Hamilton 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.16 No.3

Tendon failures in bonded post-tensioned bridges over the last two decades have motivated ongoing investigations on various aspects of unbonded tendons and their monitoring methods. Recent research shows that change of strain distribution in anchor heads can be useful in detecting wire breakage in unbonded construction. Based on this strain variation, this paper develops a damage detection model that enables an automated tendon monitoring system to identify and locate wire breaks. The first part of this paper presents an experimental program conducted to study the strain variation in anchor heads by generating wire breaks using a mechanical device. The program comprised three sets of tests with fully populated 19-strand anchor head and evaluated the levels of strain variation with number of wire breaks in different strands. The sensitivity of strain variation with wire breaks in circumferential and radial directions of anchor head in addition to the axial direction (parallel to the strand) were investigated and the measured axial strains were found to be the most sensitive. The second part of the paper focuses on formulating the wire breakage detection framework. A finite element model of the anchorage assembly was created to demonstrate the algorithm as well as to investigate the asymmetric strain distribution observed in experimental results. In addition, as almost inevitably encountered during tendon stressing, the effects of differential wedge seating on the proposed model have been analyzed. A sensitivity analysis has been performed at the end to assess the robustness of the model with random measurement errors.

PREPARATION AND CHARACTERISTICS OF FUNCTIONALIZED MULTIWALLED CARBON NANOTUBES IN POLYIMIDE MIXED MATRIX MEMBRANE

Suhaila M Sanip,A. F. ISMAIL,P. S. GOH,B. C. NG,M. S. ABDULLAH,T. SOGA,M. TANEMURA,H. YASUHIKO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2010 NANO Vol.5 No.4

The functionalization of multiwalled carbon nanotubes (MWNTs) with β cyclodextrin (β-CD) is described. The functionalization using β-CD treatment is an environmentally friendly and nondestructive method to modify carbon nanotubes. It was observed that the degree of functionalization increases with increasing ratios of β-CD as seen from the Raman analysis. The Raman spectra also indicated that the nanotubes walls were not damaged. The presence of functional groups associated with β-CD on the functionalized MWNTs indicated that the cyclodextrin groups were found to be adsorbed at the surface of the nanotubes walls. Mixed matrix membrane (MMM) was prepared by a phase inversion process. Enhanced selectivity and permeability for CO2 over CH4 was observed for MMM prepared using functionalized MWNTs.

Hierarchical composite catalysts of MCM-41 on zeolite Beta for conversion of heavy reformate to xylenes

Syed A. Ali,Faisal M. Almulla,B. Rabindran Jermy,Abdullah M. Aitani,Raed H. Abudawoud,Mohammed AlAmer,Ziyauddin S. Qureshi,Thamer Mohammad,Hassan S. Alasiri 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

Hierarchical composites of MCM-41 on zeolite Beta were synthesized by in-situ hydrothermal technique,characterized and their catalytic performance for converting heavy reformate into valuable xylenes wasevaluated. Systematic optimization of the hierarchical pore generation was carried out by varying thestrength of the alkaline solution (0.10 0.45 M NaOH) during disintegration of zeolite Beta. Thenanocomposites obtained were extruded with alumina binder and impregnated with 4.0 wt% Mo. Thecharacterization results indicate the transition of mesophase occurs from distinct disordered phase toordered/disordered and then to ordered mesophase with increasing alkaline concentration. The xyleneyield over the hierarchical composite zeolite was 1.4 times more than the parent zeolite Beta. Incorporation of a well-dispersed mild hydrogenation function (4 wt.% Mo) was advantageous inimproving the xylene yield and selectivity. The formulation prepared with moderately alkaline (0.2 MNaOH) solution exhibited optimum bimodal pore structure and improved dealkylation and transalkylationconversion resulting in a xylene yield of 33.0 wt.% and 1.7 times enhancement in xyleneselectivity over parent zeolite Beta. A 30 h stability test showed steady performance and xylene yields. Hence, a potential application of hierarchical zeolite Beta and MCM-41 composite catalysts for theconversion of heavy aromatics to produce xylenes has been successfully demonstrated.

Anthraquinones from Cell Suspension Culture of Morinda elliptica

Jasril, Jasril,Lajis, N.H.,Abdullah, M.A.,Ismail, N.H.,Ali, A.M.,Marziah, M.,Ariff, A.B.,Kitajima, M.,Takayama, H.,Aimi, N. The Korean Society of Pharmacognosy 2000 Natural Product Sciences Vol.6 No.1

The chemical investigation on the cell suspension culture of Morinda elliptica L. yielded eight anthraquinones, two of which, anthragallol-1,2-dimethyl ether (3) and purpurin-1-methyl ether (4), have not been isolated from the original plant. Other compounds isolated include nordamnacanthal (1), alizarin-1-methyl ether (2), rubiadin (5), soranjidiol (6), $lucidin-{\omega}-methyl$ ether (7), and morindone (8). The structures of anthraquinones were established based on spectral studies.

Performance Evaluation of the RTK-GNSS Navigating under Different Landscape

K.M. Ng,J. Johari,S.A.C. Abdullah,A. Ahmad,B. N. Laja 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

The navigation of autonomous vehicles depends on various sensors. One of the technologies that assist in the vehicles position localization and navigation is the Global Positioning System (GPS). Enhancement of the GPS technology reveals the application of Real Time Kinematics (RTK)-GPS to achieve higher accuracy based on corrections sent from a base station to the receiver. However, there is limited evaluation of the performance of the RTK-GPS when the vehicle is travelling in land area that is obstructed by buildings and also in uneven landscape. Hence, the purpose of this work is to conduct an experimental and comparative study to evaluate the performance of the RTK-GPS in flat-unobstructed, uneven-unobstructed and uneven-obstructed situations respectively. Three locations that possess the respective landscape characteristics in the state of Selangor, Malaysia were chosen to conduct the experiments. Results of logged RTK coordinates were compared with coordinates of the actual path travelled by the vehicle using statistical methods. In addition, the quality indicators of the coordinates logged were also evaluated. The results show that navigation on flat-unobstructed and uneven-unobstructed landscape has similar performances with floating coordinates range of errors.