Structural and electrical properties of the α-form of metal-free phthalocyanine (α-H2Pc) semiconducting thin films

N. M. Amar,R. D. Gould,A. M. Saleh 한국물리학회 2002 Current Applied Physics Vol.2 No.6

An X-ray structural study of thermally evaporated metal-free phthalocyanine thin lms with various lm thicknesses was per-formed. All samples studied had polycrystalline structure and the unit cell was found to be of thea-form. Variation of the depositionrate from 0.5 to 1 nms. 1 had little eect on the structure. The lms exhibit preferential orientation at low thickness; however, atsignicant low angle peak with increasing thickness is attributed to the increased volume of the crystal probed during the X-rayexposure.The current densityvoltage (JV) characteristics ofa-H2Pc lms sandwiched between two aluminum electrodes showed ohmicbehavior at low voltages and spacecharge-limited conduction (SCLC) at higher voltages. For comparison, similar measurements ofthe current density as a function of voltage were performed on zinc phthalocyanine, ZnPc, thin lms using aluminum electrodes. TheJV higher voltages. Consequently, in both H2Pc and ZnPc lms, aluminum electrodes act as if they are ohmic contacts. The impliedprovision of ohmic contacts using aluminum in this case is attributed to the formation of a thin Al2O3 layer during the depositionprocess.. 2002 Elsevier Science B.V. All rights reserved.

Characterization and UV Protection of Cotton and Cotton/Polyester Blend Fabrics Coated With PVA/PLST/ZnO NPs Nanocomposites Under the Effect of Gamma Irradiation

Nisreen M. Ali,Saleh N. Saleh,Magdy Ahmed,Mahmoud S. Hassan,Abdel Wahab M. El‑Naggar 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

The main objective of this work is to impart UV protection properties to cotton and cotton/polyester fabrics and enhance the original chemical and physical properties. In this procedure, the fabrics were coated with nanocomposites based on poly(vinyl alcohol)/plasticized starch (PVA/PLST (80/20%)/Zn NPs. The coated fabrics were then exposed to gamma radiation to induce cross-linked layer structure covering the fibers of the fabrics. The formation of Zn NPs was confirmed by UV/Vis and XRD analysis. In addition, the coated fabrics were characterized by the measurements of water absorption, crease recovery, thermal stability, surface morphology and tensile mechanical measurements. The UV protection of the coated fabrics was determined. The results indicated that the coated fabrics showed highly reducing UV-A, UV-B and ultraviolet protection factor (UPF), particularly with increasing irradiation dose, regardless of fabric kind. It was found that cotton and cotton/PET fabrics treated with PVA/PLST/Zn NPs nanocomposites irradiated to a dose of 30 kGy displayed UPF excellent rating values of 44.31 and 58.23, respectively.

Investigation of photon, neutron and proton shielding features of H₃BO₃-ZnO-Na₂O-BaO glass system

Mhareb, M.H.A.,Alajerami, Y.S.M.,Dwaikat, Nidal,Al-Buriahi, M.S.,Alqahtani, Muna,Alshahri, Fatimh,Saleh, Noha,Alonizan, N.,Saleh, M.A.,Sayyed, M.I. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.3

The current study aims to explore the shielding properties of multi-component borate-based glass series. Seven glass-samples with composition of (80-y)H₃BO₃-10ZnO-10Na₂O-yBaO where (y = 0, 5, 10, 15, 20, 25 and 30 mol.%) were synthesized by melt-quench method. Various shielding features for photons, neutrons, and protons were determined for all prepared samples. XCOM, Phy-X program, and SRIM code were performed to determine and explain several shielding properties such as equivalent atomic number, exposure build-up factor, specific gamma-ray constants, effective removal cross-section (Σ_R), neutron scattering and absorption, Mass Stopping Power (MSP) and projected range. The energy ranges for photons and protons were 0.015-15 MeV and 0.01-10 MeV, respectively. The mass attenuation coefficient (μ/ρ) was also determined experimentally by utilizing two radioactive sources (¹⁶⁶Ho and ¹³⁷Cs). Consistent results were obtained between experimental and XCOM values in determining μ/ρ of the new glasses. The addition of BaO to the glass matrix led to enhance the μ/ρ and specific gamma-ray constants of glasses. Whereas the remarkable reductions in Σ_R, MSP, and projected range values were reported with increasing BaO concentrations. The acquired results nominate the use of these glasses in different radiation shielding purposes.

The Technique of Voltage Level Time Division Based on Maximum Pulse Width to Reduce Total Harmonic Distortion on Multilevel Transformerless Photovoltaic Inverter (MLTPVI) System

Irwanto M.,Gomesh N.,Irwan Y. M.,Ismail B.,Leow W. Z.,Hardi S.,Saleh K.,Alam H.,Suwarno 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

An inverter is an important component used to generate alternating current (AC). One of the most common types is the multilevel inverter (MLI), which generates an AC multilevel voltage waveform. This device is designed from a simple topology with the power switching components in the full-bridge circuit connected in a series connection. The circuit consists of a total harmonic distortion (THD), voltage total harmonic distortion (VTHD), and current total harmonic distortion (CTHD). However, creating a suitable MLI technique capable of generating AC multilevel voltage waveform to achieve the lowest harmonic is one of the problems commonly faced. Therefore, this research aims to design a voltage level time division based on maximum pulse width to reduce THD on a multilevel transformerless photovoltaic inverter (TPVI) system. The direct current supplied to this is from the photovoltaic (PV) module. This research also aims to generate the phase delay time and pulse width of waves by proposing a division factor, n, proposed through mathematical modeling and simulated using SIMULINK Matlab. The results showed that the modeled PV is valid to the datasheet, therefore, it is suitable to supply the 11-level TPVI system. Furthermore, the proposed technique has the ability to generate the AC 11-level voltage waveform with diff erent division factors, n . The lowest VTHD and CTHD are achieved at values of 8, respectively.

Research Articles : Optimal Culture Conditions for Mycelial Growth of Lignosus rhinocerus

( W. H. Lai ),( M. J. Siti Murni ),( D. Fauzi ),( O. Abas Mazni ),( N. M. Saleh ) 한국균학회 2011 Mycobiology Vol.39 No.2

Lignosus rhinocerus is a macrofungus that belongs to Polyporaceae and is native to tropical regions. This highly priced mushroom has been used as folk medicine to treat diseases by indigenous people. As a preliminary study to develop a culture method for edible mushrooms, the cultural characteristics of L. rhinocerus were investigated in a range of culture media under different environmental conditions. Mycelial growth of this mushroom was compared on culture media composed of various carbon and nitrogen sources in addition to C/N ratios. The optimal conditions for mycelial growth were 30˚C at pH 6 and 7. Rapid mycelial growth of L. rhinocerus was observed on glucose-peptone and yeast extract peptone dextrose media. Carbon and nitrogen sources promoting mycelial growth of L. rhinocerus were glucose and potassium nitrate, respectively. The optimum C/N ratio was approximately 10:1 using 2% glucose supplemented as a carbon source in the basal media.

Reduced Graphene Oxide Screen-Printed FTO as Highly Sensitive Electrodes for Simultaneous Determination of Dopamine and Uric Acid

Ahammad, A. J. Saleh,Islam, Tamanna,Hasan, Md. Mahedi,Mozumder, M. N. Islam,Karim, Rejwana,Odhikari, Noyon,Pal, Poly Rani,Sarker, Subrata,Kim, Dong Min The Electrochemical Society 2018 Journal of the Electrochemical Society Vol.165 No.5

<P>A novel electrochemical sensor was fabricated by simply screen printing reduced graphene oxide (rGO) paste on F-doped tin oxide (FTO) (rGO-SP-FTO) followed by sintering at 450 degrees C in Argon and employed for detecting dopamine (DA) and uric acid (UA) simultaneously. The rGO film was characterized by using Raman spectroscopy, field emission scanning electron microscope (FE-SEM), and Fourier transform infrared spectroscopy (FTIR). The surface sensing features of rGO-SP-FTO were studied with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The rGO-SP-FTO electrode exhibited foremost sensitivity in simultaneous detection of DA and UA without any interference from ascorbic acid (AA). The rGO-SP-FTO electrode showed a good linear response in the range of 0.5-50.0 mu M and 5.0-300 mu M with detection limits (S/N = 3) of 0.07 mu M and 0.39 mu M for DA and UA, respectively. The interactions between screen printed rGO with FTO electrode and their influence on how rGO-SP-FTO electrode interacted with UA, DA, and AA were analyzed from experimental observations. The rGO-SP-FTO electrode was able to detect DA in dopamine hydrochloride injection (DAI) and UA in urine sample effectively. Moreover, the designed electrochemical sensor exhibited excellent stability and reproducibility. (C) 2018 The Electrochemical Society.</P>

Duplex and Composite Coatings: A Thematic Review on Thermal Spray Techniques and Applications

M. Sathish,N. Radhika,Bassiouny Saleh 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.5

Thermal spraying is a broad terminology for a coating process in which materials are deposited in a spray of finely distributedliquefied or semi-liquefied particulates to build layered deposition coatings. Duplex and composite coatings can be utilizedin the thermal spray technique to enhance the tribological properties of a broad range of engineering materials while savingmoney; service life extension, maintenance expenses, and replacement costs are lower than for single-layered coatings. As aresult, this paper critically analyses various pre-processing surface treatments for substrates, commonly used thermal sprayprocessing methods, and various post-processing surface treatments for thermally sprayed substrate materials. This paperalso includes a description of several characterization methodologies as well as some comprehensive prospective applicationsfor engineering components with challenges and scopes. Thus, this paper provides a fundamental understanding of surfacetreatments to researchers who use thermal spray coating techniques.

Performance of Double Fed Induction Machine at Sub- and Super-Synchronous Speed in Wind Energy Conversion System

Mona N. Eskander,Mahmoud A.Saleh,Mohsen M.T. El-Hagry 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4

In this paper two modes of operating a wound rotor induction machine as a generator at sub-and super-synchronous speeds in wind energy conversion systems are investigated. In the first mode, known as double fed induction generator (DFIG), the rotor circuit is fed from the ac mains via a controlled rectifier and a forced commutated inverter. Adjusting the applied rotor voltage magnitude and phase leads to machine operation as a generator at sub-synchronous speeds. In the second mode, the machine is operated in a slip recovery scheme where the slip energy is fed back to the ac mains via a rectifier and line commutated inverter. This mode is described as double output induction generator (DOIG) leading to increase the efficiency of the wind-to electrical energy conversion system. Simulated results of both modes are presented. Experimental verification of the simulated results are presented for the DOIG mode of operation, showing larger amount of power captured and better power factor when compared to conventional induction generators.

Anti-tumor Promoting Activity of Some Malaysian Traditional Vegetable (Ulam) Extracts by Immunoblotting Analysis of Raji Cells

A. M. Ali,L. Y. Mooi,K. Yih Yih,A. W. Norhanom,K. Mat Saleh,N. H. Lajis,A. M. Yazid,F. B. H. Ahmad,U. Prasad 한국생약학회 2000 Natural Product Sciences Vol.6 No.3

The extracts of Carica papaya (flower), Barringtonia macrostachya (leaves), Coleus tuberosus (tuber), Mangifera indica (fruit skin) and Eugenia polyantha (leaves) showed strong in vitro anti-tumor promoting activity when assayed using Raji cells (Mooi et al., 1999). The anti-tumor promoting activity of the crude extracts was further analyzed by immunoblotting analysis of Raji cells carrying Epstein-Barr virus genome. The expression of early antigens diffuse (EA-D) and early antigens restricted (EA-R) was determined by performing western blotting of treated Raji cells with human sera of nasopharyngeal carcinoma patients. All the plant extracts were shown to be able to suppress both EA-D and EA-R.

Antibacterial compounds in green microalgae from extreme environments: a review

Little, Shannon M.,Senhorinho, Gerusa N.A.,Saleh, Mazen,Basiliko, Nathan,Scott, John A. The Korean Society of Phycology 2021 ALGAE Vol.36 No.1

Increased proliferation of bacterial resistance to antibiotics is a critical issue that has increased the demand for novel antibacterial compounds. Antibacterial activities have been evaluated in extracts from photosynthetic green microalgae, with varying levels of subsequent potential for development based on the strain of algae, strain of bacterial pathogen, and solvent used to extract the metabolites. Green microalgae from extreme environmental conditions have had to adapt to conditions that exclude many other organisms. The production of antibacterial compounds aids directly or indirectly in the survival of green microalgae in these extreme environments, as well as potentially serve other roles. This review investigates antibacterial activities of green microalgae from both extreme in-situ environmental conditions and induced extreme laboratory conditions and highlights.