Switch-on Phenomena and Field Emission from Multi-Walled Carbon Nanotubes Embedded in Glass

Bani Ali, Emad S,Mousa, Marwan S Korean Society of Microscopy 2016 Applied microscopy Vol.46 No.4

This paper describes a new design of carbon nanotube tip. $Nanocly^{TM}$ NC 7000 Thin Multiwall Carbon Nanotubes of carbon purity (90%) and average diameter tube 9.5 nm with a high aspect-ratio (>150) were used. These tips were manufactured by employing a drawing technique using a glass puller. The glass microemitters with internal carbon nanotubes show a switch-on effect to a high current level (1 to $20{\mu}A$). A field electron microscope with a tip (cathode)-screen (anode) separation at ~10 mm was used to characterize the electron emitters. The system was evacuated down to a base pressure of ${\sim}10^{-9}$ mbar when baked at up to ${\sim}200^{\circ}C$ overnight. This allowed measurements of typical Field Electron Emission characteristics; namely the current-voltage (I-V) characteristics and the emission images on a conductive phosphorus screen (the anode). Fowler-Nordheim plots of the current-voltage characteristics show current switch-on for each of these emitters.

Relationship Between Corporate Social Responsibility Expenditures and Performance in Jordanian Commercial Banks

BANI-KHALED, Sakhr M.,EL-DALABEEH, Abdel Rahman K.,AL-OLIMAT, Nofan H.,AL SHBAIL, Mohannad O. Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

This study aims to examine the relationship between corporate social responsibility (CSR) expenditures and both financial and non-financial performance of Jordanian commercial banks during the period 2008-2018. To measure the variables of interest, secondary data published on Amman Stock Exchange (ASE) website were processed to become preliminary data suitable for the nature of the study. The study sample amounted to 13 commercial banks, which represent all Jordanian commercial banks listed on ASE.. The study found that there is a positive, statistically significant relationship between CSR expenditures and financial performance, as the study showed that the return on equity (ROE) has a positive and significant relationship with CSR expenditure, while the return on assets (ROA) and Tobin's Q model have a statistically significant negative relationship with CSR expenditure, while the market stock price (MSP) had a positive, but not statistically significant. The study also found that there is a positive, statistically significant relationship between CSR expenditures and non-financial performance, which was represented by total deposits and total training expenditures in Jordanian commercial banks. Accordingly, the study recommends encouraging banks to prepare sustainability reports and CSR reports, which are considered comprehensive, and not only with disclosures within the annual reports.

Folded Ranked Set Sampling for Asymmetric Distributions

Bani-Mustafa, Ahmed,Al-Nasser, Amjad D.,Aslam, Muhammad The Korean Statistical Society 2011 Communications for statistical applications and me Vol.18 No.1

In this paper a new sampling procedure for estimating the population mean is introduced. The performance of the new population mean estimator is discussed, along with its properties, and it is shown that the proposed method generates an unbiased estimator. The relative efficiency of the suggested estimator is computed, in regards to the simple random sample(SRS), and comparisons are made to the ranked set sampling(RSS) and extreme ranked set sampling(ERSS) estimators used for asymmetric distributions. The results indicate that the proposed estimator is more efficient than the estimators based on the ERSS. In addition, the folded ranked set sampling(FRSS) procedure has an advantage over the RSS and ERSS in that it reduces the number of unused sampling units.

Health monitoring of a historical monument in Jordan based on ambient vibration test

Bani-Hani, Khaldoon A.,Zibdeh, Hazem S.,Hamdaoui, Karim Techno-Press 2008 Smart Structures and Systems, An International Jou Vol.4 No.2

This paper summarizes the experimental vibration-based structural health monitoring study on a historical monument in Jordan. In this work, and within the framework of the European Commission funded project "wide-Range Non-Intrusive Devices Toward Conservation of Historical Monuments in the Mediterranean Area", a seven and a half century old minaret located in Ajloun (73 km north of the capital Amman) is studied. Because of their cultural value, touristic importance and the desire to preserve them for the future, only non-destructive tests were allowed for the experimental investigation of such heritage structures. Therefore, after dimensional measurements and determination of the current state of damage in the selected monument, ambient vibration tests are conducted to measure the accelerations at strategic locations of the system. Output-only modal identification technique is applied to extract the modal parameters such as natural frequencies and mode shapes. A Non-linear version of SAP 2000 computer program is used to develop a three-dimensional finite element model of the minaret. The developed numerical model is then updated according to the modal parameters obtained experimentally by the ambient-vibration test-results and the measured characteristics of old stone and deteriorated mortar. Moreover, a parametric identification method using the N4Sid state space model is employed to model the dynamic behavior of the minaret and to build up a robust, immune and noise tolerant model.

DSCE: Comparative Analysis of Heuristic Computational Techniques

Nooh Bany Muhammad,Sajjad A. Ghauri,Mubashar Sarfraz,Adnan Aftab 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.3

A frequency-selective fast-fading channel degrades the performance of a signal as it introduces inter-symbol interference (ISI) and inter-carrier interference (ICI). Equalization is the process of eliminating ISI and ICI by adaptively updating the tap weights of the FIR filter. The work presented utilizes various heuristic computational techniques (HCTs) to adaptively update the weights for doubly selective channel equalization (DSCE). Various HCTs are also compared, including genetic algorithms (GAs), particle swarm optimization (PSO), differential evolution (DE), cat swarm optimization (CSO), bee colony optimization (BCO), hybrid GA-PSO (HGP), and the cuckoo search algorithm (CSA). Extensive simulations were performed in MATLAB, and the simulation results show that PSO outperforms the other HCTs in terms of computational time complexity and FoM.

Molecular dynamics investigation of pull-in instability in graphene sheet under electrostatic and van der Waals forces

Sha'bani, Farzin,Rash-Ahmadi, Samrand Techno-Press 2021 Advances in nano research Vol.11 No.2

This paper investigates the pull-in instability of graphene sheets. The influence of geometry parameters such as chirality of graphene and length to gap ratio is studied using molecular dynamics (MD). For molecular interactions, the AIREBO potential is used. Furthermore, by applying the electrostatic and van der Waals (vdW) forces, pull-in voltages are calculated. Size effect is estimated, with adding the fringing field effect correction factor to the electrostatic force. In MD simulations, the graphene sheets on the armchair and zigzag structure have been investigated. The results show that the closer the moving electrode to the fixed electrode, the greater the effect of van der Waals force than the electrostatic force. The results also represent that the vdW force and fringing effect on the electrostatic load increases the pull-in deflection and decrease the pull-in voltage. The numerical results of the present study show good agreement with previous analytical and experimental researches.

Revealing the Effects of Strain and Alloying on Primary Irradiation Defects Evolution in Tantalum Through Atomistic Simulations

Mohammad Bany Salman,Minkyu Park,Mosab Jaser Banisalman 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.12

In this study, we employed molecular dynamics simulations to explore the influence of strain on primary defect formationand interstitial dislocation loop (IDL) development in pure tantalum (Ta) and Ta-20 W alloy systems under collision cascadeevents. The investigation considered primary knock-on atom (PKA) energies ranging from 5 to 30 keV at 30 K andsubjected volumetric structures to six distinct strain values, encompassing both compressive and tensile strains. Our resultsrevealed that the number of surviving Frenkel pairs (FPs) and self-interstitial atom (SIA) clusters increased with tensilestrain and decreased with compressive strain, with the Ta-20 W alloy exhibiting the lowest observed numbers compared topure Ta. Notably, SIA clusters in pure Ta were approximately double those in alloyed structures for clusters containing twoto four atoms. We also observed that pure Ta systems displayed larger and longer IDL segments than alloyed Ta systems,which featured smaller and shorter IDLs. The applied strain was found to lower the barrier for IDL formation, potentiallyleading to material degradation. In conclusion, this study highlights the importance of considering the effects of strainand alloying in radiation-damaged environments, particularly in low-temperature, high-radiation-energy environments.

Price- and Rate-aware Multi-channel Spectrum Access for Profit Enhancement in Opportunistic Networks with QoS Guarantees

Haythem Bany Salameh,Ghaleb El Refae 한국통신학회 2022 ICT Express Vol.8 No.1

Cognitive radio (CR) is a key technology that can enable opportunistic spectrum access, which enables secondary users (SUs) to dynamically exploit the under-utilized channels in the licensed spectrum, owned by primary radio networks (PRNs), referred to as dominant firms. Such sharing is subject to interference, SU QoS and cost constraints, in which SUs should not introduce harmful interference to PR users, achieve QoS rate demand and pay a price for using the licensed PR spectrum. The price of accessing idle PR channels depends on the level of channel utilization and price paid by PRs to access the channels, while the amount of needed spectrum to serve the rate demand of each SU heavily depends on the link-quality of the various channels. In this paper, the spectrum assignment problem in a CR network (CRN), referred to as follower firm, is investigated with the target of serving the largest possible number of SUs with the least possible total price paid to the PRNs (highest CRN profit) while being aware of the time-varying achieved transmission rate and level of utilization of the various PR channels. The problem is mathematically expressed as an optimization problem with the goal of maximizing the number of served SUs and the profit made by the CRN, which has been shown to be a binary linear programming (BLP) problem. Due to the high complexity of solving such optimization, we use the well-known sequential-fixing optimization method to obtain sub-optimal solutions. Simulation results indicate that our channel-assignment optimization significantly increases the CRN profit by reducing the price paid to the PRNs while achieving comparable performance offered by previous price-unaware protocols.

The Synthesis and Characterization of Fatty Acid Salts of Chitosan as Novel Matrices for Prolonged Intragastric Drug Delivery

Ahmad Bani-Jaber,Imad Hamdan,Mahmoud Alkawareek 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.7

The aim of this study was to prepare fatty acid salts of chitosan (CS) and to evaluate the salts as matrices for sustained drug release and prolonged gastric retention. CS-laurate and CSpalmitate were formed by mixing saturated CS solution and aqueous solutions of sodium laurate and sodium palmitate, respectively, and collected by centrifugation. They were characterized using Fourier-transform infrared spectroscopy and differential scanning calorimetry. Different matrices as effervescent tablets were prepared using each of these CS-salts, CS and the corresponding physical mixtures of CS and the fatty acids. Sodium bicarbonate as an effervescent agent and ranitidine HCl as a model drug were incorporated into these matrices. In vitro buoyancy and drug dissolution were studied for the matrices in 0.1 M HCl. Tablets with fatty acid salts of CS showed both rapid and prolonged buoyancy (> 8 h). Comparatively, CS tablets exhibited a short floatation period (< 2 h) and tablets were completely disintegrated within 1 h of soaking. In addition, slow and prolonged drug release was achieved from tablets of fatty acid salts of CS with average drug release of 80.1 and 71.8% for CS-laurate and CSpalmitate, respectively. Rapid drug release (> 80% at 1 h) was exhibited by tablets with CS or the physical mixtures.

An Evaluation Model for Social Development Environments

Hani Bani-Salameh,Sanaa Alwidian,Maen Hammad,Fadi Wedyan 보안공학연구지원센터 2014 International Journal of Software Engineering and Vol.8 No.1