Variation of Li Diffusion Coefficient during Delithiation of Spinel LiNi_0.5Mn_1.5O₄

Rahim, Ahmad Syahmi Abdul,Kufian, Mohd Zieauddin,Arof, Abdul Kariem Mohd,Osman, Zurina The Korean Electrochemical Society 2022 Journal of electrochemical science and technology Vol.13 No.1

For this study, the sol gel method was used to synthesize the spinel LiNi_0.5Mn_1.5O₄ (LNMO) electrode material. Structural, morphological, electrochemical, and kinetic aspects of the LNMO have been characterized. The synthesized LNMO was indexed with the Fd3m cubic space group. The excellent capacity retention indicates that the spinel framework of LNMO has the ability to withstand high rate charge-discharge throughout long cycle tests. The Li diffusion coefficient (D_Li) changes non-monotonically across three orders of magnitude, from 10^-9 to 10^-12 cm² s^-1 determined from GITT method. The variation of D_Li seemed to be related to three oxidation reactions that happened throughout the charging process. A small dip in D_Li at the beginning stage of Li deintercalation is correlated with the oxidation of Mn³⁺ to Mn⁴⁺. While two pronounced D_Li minima at 4.7 V and 4.75 V are due to the oxidation of Ni²⁺/Ni³⁺ and Ni³⁺/Ni⁴⁺ respectively. The depletion of D_Li at the high voltage region is attributed to the occurrence of two successive phase transformation phenomena.

Biochemical screening of Lactobacilli in midgut of wild Aedes aegypti mosquitoes. A step toward paratransgenesis candidate

Alhaji Hamisu Maimusa,Abu Hassan AHMAD,Nur Faeza Abu Kassim,Hamdan Ahmad,Hamady Dieng,Junaid RAHIM,Muhammad Ahmad DAHIRU 한국곤충학회 2019 Entomological Research Vol.49 No.2

This study was conducted to isolate and identify lactobacilli from larval and adult midgut of wild Aedes aegypti (Ae. aegypti) to find candidate bacteria for paratransgenic control. Characterization of the bacterial symbionts was done using Gram staining, motility test, catalase test, and biochemical tests, among others, and the morphological features were confirmed using a standard scheme that simplifies the identification of lactic acid bacteria. A total of 174 strains were isolated and identified, 135 strains from larval midgut and 39 strains from adult midgut (mean ± SE, 4.00 ± 0.72; P = 0.00). The isolated species were confirmed to be Lactobacillus fermentum, L. casei, L. acidophilus, L. viridescens, L. brevis and L. gasseri. It can be concluded that Ae. aegypti has the potential of harboring the cultivable bacterial symbionts. In conclusion, the isolated species were nominated for paratransgenic control, particularly L. fermentum, being found in large numbers from both larval and adulxt midgut.

EFFECT OF CROSSWINDS ON THE AERODYNAMICS OF TWO PASSENGER CARS CROSSING EACH OTHER

Ahmad Hammad,Tao Xing,Ahmed Abdel-Rahim,Vibhav Durgesh,John C. Crepeau 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.5

The impact of aerodynamics on vehicle safety during crossing of passenger cars is investigated, in the absence and presence of 30o crosswind. Three-dimensional, unsteady computational fluid dynamics (CFD) simulations were used to simulate these maneuvers. The vortical structures surrounding one car in the case without crosswind were analyzed, establishing the connection between force and moment fluctuations pre-interaction and the shedding frequency of these vortices. The forces and moments acting on a passenger car during a crossing maneuver may change by up to 43 %, with the maximum change associated with the windward car in the presence of crosswind. However, the duration of this increase in forces is at most 0.01 s, which will not affect the stability of vehicles under normal conditions. The presence of crosswind increased the rate of fluctuation of forces and moments. Wind tunnel experimental results are in good agreement with the simulations, and the data available in literature. The analysis results do not show the necessity of enacting new safety policies on highways, but future parametric studies are needed to fully investigate the impact of different crosswind speeds and directions, the impact of discrepancy in vehicles sizes, and different vehicle lateral separating distances during crossing and overtaking.

Increasing Network Lifetime and Data Transfer through Node Vulnerability Aware Routing in Wireless Sensor Networks

Rahim Khan,Shah Nawaz Khan,Mushtaq Ahmad 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

In this paper, we propose a routing technique that takes into account the importance of a particular node for the overall network connectivity for routing. We show that some nodes are more important than others and need to be used sporadically for data forwarding. Avoiding the use of such important nodes results in prolonging network lifetime and maximizing the data transfer. Simulation results are shown to confirm the effectiveness of the proposed technique.

Privacy-preserving image retrieval for mobile devices with deep features on the cloud

Rahim, Nasir,Ahmad, Jamil,Muhammad, Khan,Sangaiah, Arun Kumar,Baik, Sung Wook Elsevier 2018 Journal of Computer Communications Vol.127 No.-

<P><B>Abstract</B></P> <P>With the prevalent use of mobile cameras to capture images, the demands for efficient and effective methods for indexing and retrieval of personal image collections on mobile devices have also risen. In this paper, we propose to represent images with hash codes, which is a compressed representation of deep convolutional features using deep auto-encoder on the cloud. To ensure user's privacy, the image is first encrypted using a light-weight encryption algorithm on mobile device prior to offloading it to the cloud for features extraction. This approach eliminates the computationally expensive process of features extraction on resource constrained devices. A pre-trained convolutional neural network (CNN) is used to extract features which are then transformed to compact binary codes using a deep auto-encoder. The hash codes are then sent back to the mobile device where they are stored in a hash table along with image location. Approximate nearest neighbor (ANN) search approach is utilized to efficiently retrieve the desired images without exhaustive searching of the entire image collection. The proposed method is evaluated against three different publicly available image datasets namely Corel-10K, GHIM-10K, and Product image dataset. Experimental results demonstrate that features representation using CNN and auto-encoder shows much better results than several state-of-the-art hashing schemes for image retrieval on mobile devices.</P>

Electrochemical sensing of H2O2 using cobalt oxide modified TiO2 nanotubes

Ullah Rahim,Rasheed Muhammad Asim,Abbas Shafqat,Rehman Khalil-ul,Shah Attaullah,Ullah Karim,Khan Yaqoob,Bibi Maryam,Ahmad Mashkoor,Ali Ghafar 한국물리학회 2022 Current Applied Physics Vol.38 No.-

Cobalt oxide (Co3O4) modified anatase titanium dioxide nanotubes (ATNTs) have been investigated for the electrochemical sensing of hydrogen peroxide (H2O2). ATNTs have been synthesized by a two-step anodization process. ATNTs were then modified with Co3O4 employing chemical bath deposition method. The structure and morphology of ATNTs and their modification with Co3O4 has been confirmed by X-ray diffraction by scanning electron microscopy. H2O2 sensing has been studied in 0.1 M PBS solution, by cyclic voltammetry and amperometry. Variation in the peak positions and current densities was observed with addition of H2O2 for Co3O4 modified ATNTs. Sensitivity and limit of detection improved with modification of ATNTs with Co3O4 with precursor concentration up to 0.8 M. However, at higher precursor concentrations sensitivity and limit of detection toward H2O2 deteriorated. Co3O4 Modified ATNTS using 0.8 M precursor concentration are comparatively more suitable for H2O2 sensing applications due to the optimum formation of Co3O4/ATNTs heterojunctions.

Arabic Words Extraction and Character Recognition from Picturesque Image Macros with Enhanced VGG-16 based Model Functionality Using Neural Networks

Ayed Ahmad Hamdan Al-Radaideh,Mohd Shafry bin Mohd Rahim,Wad Ghaban,Majdi Bsoul,Shahid Kamal,Naveed Abbas 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.7

Innovation and rapid increased functionality in user friendly smartphones has encouraged shutterbugs to have picturesque image macros while in work environment or during travel. Formal signboards are placed with marketing objectives and are enriched with text for attracting people. Extracting and recognition of the text from natural images is an emerging research issue and needs consideration. When compared to conventional optical character recognition (OCR), the complex background, implicit noise, lighting, and orientation of these scenic text photos make this problem more difficult. Arabic language text scene extraction and recognition adds a number of complications and difficulties. The method described in this paper uses a two-phase methodology to extract Arabic text and word boundaries awareness from scenic images with varying text orientations. The first stage uses a convolution auto-encoder, and the second uses Arabic Character Segmentation (ACS), which is followed by traditional two-layer neural networks for recognition. This study presents the way that how can an Arabic training and synthetic dataset be created for exemplify the superimposed text in different scene images. For this purpose a dataset of size 10K of cropped images has been created in the detection phase wherein Arabic text was found and 127k Arabic character dataset for the recognition phase. The phase-1 labels were generated from an Arabic corpus of quotes and sentences, which consists of 15kquotes and sentences. This study ensures that Arabic Word Awareness Region Detection (AWARD) approach with high flexibility in identifying complex Arabic text scene images, such as texts that are arbitrarily oriented, curved, or deformed, is used to detect these texts. Our research after experimentations shows that the system has a 91.8% word segmentation accuracy and a 94.2% character recognition accuracy. We believe in the future that the researchers will excel in the field of image processing while treating text images to improve or reduce noise by processing scene images in any language by enhancing the functionality of VGG-16 based model using Neural Networks.

Size-Separation and Self-Assembly of Anisotropic Nanoparticles in a Coffee-Stain Ring

Imtiaz Ahmad,Rahim Jan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

Nanoparticles deposition via droplet drying technique generally leads to a coffee-stain-like ring. In the case of different shapes and sizes of nanoparticles, such ring-like deposits also demonstrate various phases within the self-assembly superstructures. For broad spectrum sizes in suspension, size-separation effect has not been considered before. Herein, polydisperse gold anisotropic nanoparticles have been prepared via wet chemical synthesis technique. High-resolution scanning electron microscopy (HRSEM) at various positions of a coffee-stain ring displayed both size-separation and self-assembly of nanoparticles. Especially at the outer edges of a ring-like deposit, side-by-side organized arrays of anisotropic nanoparticles have been observed. Likewise, such ordered arrays generally begin with thin nanorods and the width of nanoparticles increases as one moves inward within such arrays. Also, assembly of deposited arrays is more orderly arranged at the periphery of the ring, whereas such order significantly decreases at the interior region of the ring. Furthermore, it has been observed for a mixture of thick–thin nanorods and spheres that only thick nanorods self-assemble into ordered arrays whereas thin rod-sphere was found disordered everywhere within the ring. Nanoscale interactions are quantified for these systems to understand self-assembly behavior of such anisotropic nanoparticles.

Diagnostic Accuracy of Magnetic Resonance Imaging versus Clinical Staging in Cervical Cancer

Shirazi, Ahmad Soltani,Razi, Taghi,Cheraghi, Fatemeh,Rahim, Fakher,Ehsani, Sara,Davoodi, Mohammad Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: Cervical cancer is the third most common gynecological cancer and a widespread malignancy in women, accounting for a large proportion of the cancer burden in developing countries. We compared accuracy of MRI staging with clinical staging and also concordance between the two methods for newly diagnosed patients with cervical cancer, using clinical staging as the reference. Materials and Methods: This prospective study was conducted on 27 newly diagnosed patients with cervical cancer from Imam Khomeini hospital from June 2012 to Feb 2014. New cases of cervical cancer with positive PAP test were staged separately with a clinical exam based on the FIGO system by a gynecologist, oncologist and also with MRI by an expert radiologist. Then we compared the predicted stage for each patient with the two methods. Results: Based on clinical staging 9 patients (33%) were observed at stage 1. MRI staging was in coordination with clinical staging in eight of them and for one patient MRI accorded stage 2B (88% concordance). Conclusions: MRI is a reliable noninvasive method with high accuracy for cervical cancer staging. Also presently it is easily obtainable, so we recommend using this technique along with clinical examination for staging cervical cancer patients. We also recommend to radiologists and residents of radiology to get experience with this method of staging.

Performance Evaluation of Hybrid Quantum-Classical Neural Networks

Muhammad Talha Rahim,Ahmad Farooq,Kyesan Lee,Hyundong Shin 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2