Displaying publications 41 - 60 of 80 in total

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  1. Fulltext Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin
    Kadhum AAH, Mohamad AB, Hammed LA, Al-Amiery AA, San NH, Musa AY
    Materials (Basel), 2014 Jun 05;7(6):4335-4348.
    PMID: 28788680 DOI: 10.3390/ma7064335
    A new coumarin derivative, N,N'-((2E,2'E)-2,2'-(1,4-phenylenebis (methanylylidene))bis(hydrazinecarbonothioyl))bis(2-oxo-2H-chromene-3-carboxamide) PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear magnetic resonance, (1)H-NMR and carbon-13 nuclear magnetic resonance (13)C-NMR). The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM) was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.
  2. Fulltext Novel Corrosion Inhibitor for Mild Steel in HCl
    Al-Amiery AA, Kadhum AAH, Alobaidy AHM, Mohamad AB, Hoon PS
    Materials (Basel), 2014 Jan 27;7(2):662-672.
    PMID: 28788482 DOI: 10.3390/ma7020662
    Corrosion inhibitory effects of new synthesized compound namely 5,5'- ((1Z,1'Z)-(1,4-phenylenebis(methanylylidene))bis(azanylylidene))bis(1,3,4-thiadiazole-2-thiol) (PBB) on mild steel in 1.0 M HCl was investigated at different temperatures using open circuit potential (OCP), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Results showed that PBB inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiencies increased with the concentration of inhibitor, but decreased proportionally with temperature. Changes in impedance parameters suggested the adsorption of PBB on the mild steel surface, leading to the formation of protective films.
  3. Fulltext Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid
    Al-Amiery AA, Kadhum AAH, Mohamad AB, Musa AY, Li CJ
    Materials (Basel), 2013 Nov 27;6(12):5466-5477.
    PMID: 28788402 DOI: 10.3390/ma6125466
    A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, ¹H-NMR and 13C-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.
  4. Application of dyes extracted from Alternanthera dentata leaves and Musa acuminata bracts as natural sensitizers for dye-sensitized solar cells
    Al-Alwani MAM, Ludin NA, Mohamad AB, Kadhum AAH, Mukhlus A
    Spectrochim Acta A Mol Biomol Spectrosc, 2018 Mar 05;192:487-498.
    PMID: 29133132 DOI: 10.1016/j.saa.2017.11.018
    The natural dyes anthocyanin and chlorophyll were extracted from Musa acuminata bracts and Alternanthera dentata leaves, respectively. The dyes were then applied as sensitizers in TiO2-based dye-sensitized solar cells (DSSCs). The ethanol extracts of the dyes had maximum absorbance. High dye yields were obtained under extraction temperatures of 70 to 80°C, and the optimal extraction temperature was approximately 80°C. Moreover, dye concentration sharply decreased under extraction temperatures that exceeded 80°C. High dye concentrations were obtained using acidic extraction solutions, particularly those with a pH value of 4. The DSSC fabricated with anthocyanin from M. acuminata bracts had a conversion efficiency of 0.31%, short-circuit current (Isc) of 0.9mA/cm2, open-circuit voltage (Voc) of 0.58V, and fill factor (FF) of 62.22%. The DSSC sensitized with chlorophyll from A. dentata leaves had a conversion efficiency of 0.13%, Isc of 0.4mA/cm-2,Voc of 0.54V, and FF of 67.5%. The DSSC sensitized with anthocyanin from M. acuminata bracts had a maximum incident photon-to-current conversion efficiency of 42%, which was higher than that of the DSSC sensitized with chlorophyll from A. dentata leaves (23%). Anthocyanin from M. acuminata bracts exhibited the best photosensitization effects.
  5. Solar photocatalytic degradation of 2-chlorophenol with ZnO nanoparticles: optimisation with D-optimal design and study of intermediate mechanisms
    Ba-Abbad MM, Takriff MS, Kadhum AA, Mohamad AB, Benamor A, Mohammad AW
    Environ Sci Pollut Res Int, 2017 Jan;24(3):2804-2819.
    PMID: 27837474 DOI: 10.1007/s11356-016-8033-y
    In this study, the photocatalytic degradation of toxic pollutant (2-chlorophenol) in the presence of ZnO nanoparticles (ZnO NPs) was investigated under solar radiation. The three main factors, namely pH of solution, solar intensity and calcination temperature, were selected in order to examine their effects on the efficiency of the degradation process. The response surface methodology (RSM) technique based on D-optimal design was applied to optimise the process. ANOVA analysis showed that solar intensity and calcination temperature were the two significant factors for degradation efficiency. The optimum conditions in the model were solar intensity at 19.8 W/m(2), calcination temperature at 404 °C and pH of 6.0. The maximum degradation efficiency was predicted to be 90.5% which was in good agreement with the actual experimental value of 93.5%. The fit of the D-optimal design correlated very well with the experimental results with higher values of R (2) and R (2)adj correlation coefficients of 0.9847 and 0.9676, respectively. The intermediate mechanism behaviour of the 2-chlorophenol degradation process was determined by gas chromatography-mass spectrometry (GC-MS). The results confirmed that 2-chlorophenol was converted to acetic acid, a non-toxic compound.
  6. Fulltext Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers
    Yousif E, Al-Amiery AA, Kadihum A, Kadhum AA, Mohamad AB
    Molecules, 2015 Nov 04;20(11):19886-99.
    PMID: 26556323 DOI: 10.3390/molecules201119665
    The photostabilization of polyvinyl chloride (PVC) films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs) for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10(-8). According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV) absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.
  7. Fulltext Solar power forecasting beneath diverse weather conditions using GD and LM-artificial neural networks
    Sharma N, Puri V, Mahajan S, Abualigah L, Zitar RA, Gandomi AH
    Sci Rep, 2023 May 25;13(1):8517.
    PMID: 37231039 DOI: 10.1038/s41598-023-35457-1
    Large-scale solar energy production is still a great deal of obstruction due to the unpredictability of solar power. The intermittent, chaotic, and random quality of solar energy supply has to be dealt with by some comprehensive solar forecasting technologies. Despite forecasting for the long-term, it becomes much more essential to predict short-term forecasts in minutes or even seconds prior. Because key factors such as sudden movement of the clouds, instantaneous deviation of temperature in ambiance, the increased proportion of relative humidity and uncertainty in the wind velocities, haziness, and rains cause the undesired up and down ramping rates, thereby affecting the solar power generation to a greater extent. This paper aims to acknowledge the extended stellar forecasting algorithm using artificial neural network common sensical aspect. Three layered systems have been suggested, consisting of an input layer, hidden layer, and output layer feed-forward in conjunction with back propagation. A prior 5-min te output forecast fed to the input layer to reduce the error has been introduced to have a more precise forecast. Weather remains the most vital input for the ANN type of modeling. The forecasting errors might enhance considerably, thereby affecting the solar power supply relatively due to the variations in the solar irradiations and temperature on any forecasting day. Prior approximation of stellar radiations exhibits a small amount of qualm depending upon climatic conditions such as temperature, shading conditions, soiling effects, relative humidity, etc. All these environmental factors incorporate uncertainty regarding the prediction of the output parameter. In such a case, the approximation of PV output could be much more suitable than direct solar radiation. This paper uses Gradient Descent (GD) and Levenberg Maquarndt Artificial Neural Network (LM-ANN) techniques to apply to data obtained and recorded milliseconds from a 100 W solar panel. The essential purpose of this paper is to establish a time perspective with the greatest deal for the output forecast of small solar power utilities. It has been observed that 5 ms to 12 h time perspective gives the best short- to medium-term prediction for April. A case study has been done in the Peer Panjal region. The data collected for four months with various parameters have been applied randomly as input data using GD and LM type of artificial neural network compared to actual solar energy data. The proposed ANN based algorithm has been used for unswerving petite term forecasting. The model output has been presented in root mean square error and mean absolute percentage error. The results exhibit a improved concurrence between the forecasted and real models. The forecasting of solar energy and load variations assists in fulfilling the cost-effective aspects.
  8. Fulltext Mathematical modelling and analysis of COVID-19 and tuberculosis transmission dynamics
    Singh R, Rehman AU, Ahmed T, Ahmad K, Mahajan S, Pandit AK, et al.
    Inform Med Unlocked, 2023;38:101235.
    PMID: 37033412 DOI: 10.1016/j.imu.2023.101235
    In this paper, a mathematical model for assessing the impact of COVID-19 on tuberculosis disease is proposed and analysed. There are pieces of evidence that patients with Tuberculosis (TB) have more chances of developing the SARS-CoV-2 infection. The mathematical model is qualitatively and quantitatively analysed by using the theory of stability analysis. The dynamic system shows endemic equilibrium point which is stable when R 0 < 1 and unstable when R 0 > 1 . The global stability of the endemic point is analysed by constructing the Lyapunov function. The dynamic stability also exhibits bifurcation behaviour. The optimal control theory is used to find an optimal solution to the problem in the mathematical model. The sensitivity analysis is performed to clarify the effective parameters which affect the reproduction number the most. Numerical simulation is carried out to assess the effect of various biological parameters in the dynamic of both tuberculosis and COVID-19 classes. Our simulation results show that the COVID-19 and TB infections can be mitigated by controlling the transmission rate γ .
  9. Fulltext The Impact of Halloysite on the Thermo-Mechanical Properties of Polymer Composites
    Gaaz TS, Sulong AB, Kadhum AAH, Al-Amiery AA, Nassir MH, Jaaz AH
    Molecules, 2017 May 20;22(5).
    PMID: 28531126 DOI: 10.3390/molecules22050838
    Nanotubular clay minerals, composed of aluminosilicate naturally structured in layers known as halloysite nanotubes (HNTs), have a significant reinforcing impact on polymer matrixes. HNTs have broad applications in biomedical applications, the medicine sector, implant alloys with corrosion protection and manipulated transportation of medicines. In polymer engineering, different research studies utilize HNTs that exhibit a beneficial enhancement in the properties of polymer-based nanocomposites. The dispersion of HNTs is improved as a result of pre-treating HNTs with acids. The HNTs' percentage additive up to 7% shows the highest improvement of tensile strength. The degradation of the polymer can be also significantly improved by doping a low percentage of HNTs. Both the mechanical and thermal properties of polymers were remarkably improved when mixed with HNTs. The effects of HNTs on the mechanical and thermal properties of polymers, such as ultimate strength, elastic modulus, impact strength and thermal stability, are emphasized in this study.
  10. Auto-detection of the coronavirus disease by using deep convolutional neural networks and X-ray photographs
    Hussein AM, Sharifai AG, Alia OM, Abualigah L, Almotairi KH, Abujayyab SKM, et al.
    Sci Rep, 2024 Jan 04;14(1):534.
    PMID: 38177156 DOI: 10.1038/s41598-023-47038-3
    The most widely used method for detecting Coronavirus Disease 2019 (COVID-19) is real-time polymerase chain reaction. However, this method has several drawbacks, including high cost, lengthy turnaround time for results, and the potential for false-negative results due to limited sensitivity. To address these issues, additional technologies such as computed tomography (CT) or X-rays have been employed for diagnosing the disease. Chest X-rays are more commonly used than CT scans due to the widespread availability of X-ray machines, lower ionizing radiation, and lower cost of equipment. COVID-19 presents certain radiological biomarkers that can be observed through chest X-rays, making it necessary for radiologists to manually search for these biomarkers. However, this process is time-consuming and prone to errors. Therefore, there is a critical need to develop an automated system for evaluating chest X-rays. Deep learning techniques can be employed to expedite this process. In this study, a deep learning-based method called Custom Convolutional Neural Network (Custom-CNN) is proposed for identifying COVID-19 infection in chest X-rays. The Custom-CNN model consists of eight weighted layers and utilizes strategies like dropout and batch normalization to enhance performance and reduce overfitting. The proposed approach achieved a classification accuracy of 98.19% and aims to accurately classify COVID-19, normal, and pneumonia samples.
  11. Fulltext Inhibition effects of a synthesized novel 4-aminoantipyrine derivative on the corrosion of mild steel in hydrochloric acid solution together with quantum chemical studies
    Junaedi S, Al-Amiery AA, Kadihum A, Kadhum AA, Mohamad AB
    Int J Mol Sci, 2013 Jun 04;14(6):11915-28.
    PMID: 23736696 DOI: 10.3390/ijms140611915
    1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.
  12. Fulltext Severe combined immunodeficiency in a Malaysian child
    Noh LM, Amir HL, Hung LC, Zulkifli I, Nasuruddin BA
    Med J Malaysia, 1997 Mar;52(1):88-91.
    PMID: 10968061
    A 3-month-old Malay male infant presented with multiple infections (candidiasis, Pseudomonas aeruginosa, Cytomegalovirus), persistent pneumonia, intractable diarrhoea and failure to thrive. There was lymphopaenia affecting both T and B subsets. He developed Graft versus Host disease weeks following transfusion with non irradiated blood. In spite of aggressive microbicidal and supportive therapy including regular immunoglobulin infusions, the child succumbed to infection before a bone marrow transplant could be instituted.
  13. Effectiveness of Virgin Coconut Oil and Regular Repositioning in Preventing Pressure Ulcers in Children
    Andayani RP, Wahyuni F, Ausrianti R, Reni I, Edo CWD, Amir H
    Med J Malaysia, 2023 Jul;78(4):511-514.
    PMID: 37518923
    INTRODUCTION: Pressure ulcers have adverse effects on health. Thus, early detection of damage to skin integrity is important for preventing the occurrence of pressure sores. Virgin Coconut Oil (VCO) is a nonpharmacological therapy that can be applied to overcome the problem of damage to skin integrity. Virgin coconut oil contains antioxidants and is rich in vitamin E. Meanwhile, two-hourly repositioning is a nursing intervention performed to prevent pressure ulcers.

    MATERIALS AND METHODS: This study aimed to evaluate the implementation of Virgin Coconut Oil and regular repositioning for preventing pressure sores. The designs used quasi experiment pretest and posttest nonequivalent control group; 86 participants were selected through a nonprobability sampling technique by consecutive sampling.

    RESULTS: The fundings suggest that there is a significant difference in the Braden QD scores from before and after virgin coconut oil of the intervention group and repositioning of the control group (p<0.001).

    CONCLUSION: Nurses are expected to be able to detect early damage to skin integrity by using the Braden QD Scale and to implement use Virgin Coconut Oil and repositioning.

  14. Fulltext Facial Candling for the Treatment of Allergic Rhinitis in Young Adults: A Qualitative Study
    Ismail NFF, Neoh CF, Lean QY, Abdullah AH, Lim SM, Ramasamy K, et al.
    J Pharm Bioallied Sci, 2018 12 21;10(4):199-207.
    PMID: 30568377 DOI: 10.4103/JPBS.JPBS_33_18
    Aims: Facial candling is one of the traditional treatments that is claimed to be able to help in curing or reducing various allergy and inflammation conditions such as allergic rhinitis. We aimed to explore the perceptions of participants with allergic rhinitis toward their disease conditions and facial candling treatment.

    Materials and Methods: The study used a qualitative exploratory design, comprising 12 in-depth interviews. A semi-structured topic guide was used to explore all relevant aspects of the topic, which were audio recorded, transcribed verbatim. All the interviews were conducted in a few beauty salons in purposively selected city areas in the state of Kedah, Malaysia.

    Results: Of the 12 patients, seven (58%) reported a positive experience of facial candling treatment, with improvement in the condition of their allergic rhinitis. Specific themes about the experience of facial candling treatment that were identified within the transcript data included knowledge about facial candling, options for disease treatment, effectiveness of facial candling, sources of information, comparison, application of treatment, treatment budget, and safety. The major strength lies in the fact that reasons for using facial candling were uncovered from the perspectives of people with allergic rhinitis through the in-depth interviews.

    Conclusions: The motives of these participants for using facial candling are mainly due to cultural influence and its low cost of treatment. There were mixed responses from the participants about the usefulness of facial candling. Most of the respondents had not assessed the safety of prolonged use of facial candling and regarded it as a safe procedure as this has been practiced for generations.

  15. Fulltext Unique Halloysite Nanotubes⁻Polyvinyl Alcohol⁻Polyvinylpyrrolidone Composite Complemented with Physico⁻Chemical Characterization
    Gaaz TS, Kadhum AAH, Michael PKA, Al-Amiery AA, Sulong AB, Nassir MH, et al.
    Polymers (Basel), 2017 Jun 06;9(6).
    PMID: 30970887 DOI: 10.3390/polym9060207
    A halloysite nanotubes⁻polyvinyl alcohol⁻polyvinylpyrrolidone (HNTs⁻PVA⁻PVP) composite has been investigated for a quite long time aiming at improving the physico⁻chemical characterization of HNTs. In this work, HNTs⁻PVA⁻PVP composite were prepared based on a unique procedure characterized by crosslinking two polymers with HNTs. The composite of two polymers were modified by treating HNTs with phosphoric acid (H₃PO₄) and by using malonic acid (MA) as a crosslinker. The composite was also treated by adding the dispersion agent sodium dodecyl sulfate (SDS). The HNTs⁻PVA⁻PVP composite shows better characteristics regarding agglomeration when HNTs is treated in advance by H₃PO₄. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), brunauer⁻emmett⁻teller (BET), size distribution, and atomic force microscopy (AFM) are used to characterize the physio-chemical properties of the composite. FTIR shows additional peaks at 2924.29, 1455.7, and 682.4 cm-1 compared to the neat HNTs due to adding MA. Despite that, the XRD spectra do not show a significant difference, the decrease in peak intensity could be attributed to the addition of semi-crystalline PVA and the amorphous PVP. The images taken by TEM and FESEM show the possible effects of MA on the morphology and internal feature of HNTs⁻PVA⁻PVP composite treated by MA by showing the deformation of the matrix. The BET surface area increased to 121.1 m²/g compared to the neat HNTs at 59.1 m²/g. This result, the second highest recorded result, is considered a breakthrough in enhancing the properties of HNTs⁻PVA⁻PVP composite, and treatment by MA crosslinking may attribute to the size and the number of the pores. The results from these techniques clearly showed that a significant change has occurred for treated HNTs⁻PVA⁻PVP composite where MA was added. The characterization of HNTs⁻PVA⁻PVP composite with and without treating HNTs and using crosslinker may lead to a better understanding of this new composites as a precursor to possible applications in the dentistry field.
  16. Fulltext Experimental and theoretical studies of Schiff bases as corrosion inhibitors
    Jamil DM, Al-Okbi AK, Al-Baghdadi SB, Al-Amiery AA, Kadhim A, Gaaz TS, et al.
    Chem Cent J, 2018 Feb 05;12(1):7.
    PMID: 29404816 DOI: 10.1186/s13065-018-0376-7
    BACKGROUND: Relatively inexpensive, stable Schiff bases, namely 3-((4-hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ3) and 3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ4), were employed as highly efficient inhibitors of mild steel corrosion by corrosive acid.

    FINDINGS: The inhibition efficiencies were estimated based on weight loss method. Moreover, scanning electron microscopy was used to investigate the inhibition mechanism. The synthesized Schiff bases were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and micro-elemental analysis. The inhibition efficiency depends on three factors: the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight.

    CONCLUSIONS: Inhibition efficiencies of 96 and 92% were achieved with BZ4 and BZ3, respectively, at the maximum tested concentration. Density functional theory calculations of BZ3 and BZ4 were performed to compare the effects of hydroxyl and N,N-dimethylamino substituents on the inhibition efficiency, providing insight for designing new molecular structures that exhibit enhanced inhibition efficiencies.

  17. Fulltext Palmitic acid-based amide as a corrosion inhibitor for mild steel in 1M HCl
    Al-Edan AK, Roslam Wan Isahak WN, Che Ramli ZA, Al-Azzawi WK, Kadhum AAH, Jabbar HS, et al.
    Heliyon, 2023 Apr;9(4):e14657.
    PMID: 37025890 DOI: 10.1016/j.heliyon.2023.e14657
    Due to growing environmental concerns and regulations limiting the use of harmful and toxic synthetic corrosion inhibitors, there is a high demand for sustainable corrosion inhibitors. In this study, a green and rapid technique was used to synthesize amide N-(4-aminobutyl)palmitamide (BAPA) which yielded 91.17% of the product within 2 min, compared to a low yield of 75-80% and a very long 8-10 h reaction time with the conventional thermal condensation method. The chemical structure of BAPA was analyzed by FT-IR, 1HNMR and 13CNMR spectra, as well as CHNS elemental analysis. When applied to mild steel exposed to 1 M HCl, BAPA delayed and reduced corrosion by adsorbing to the steel surface to form a protective layer. The inhibition efficiency increased with increasing amide concentration, and maximal inhibition of 91.5% was observed at 0.5 mM BAPA. The adsorption of BAPA on mild steel in an acidic solution was studied and inhibition performance was correlated with the calculated adsorption-free energy ΔGads, indicating good agreement between the experimental and adsorption findings. Surface morphology of untreated and treated mild steel coupons was evaluated by SEM, and based on density functional theory (DFT) computations and atomic charges analysis, a stronger interaction was observed between BAPA and mild steel surface leading to the formation of a compact protective film on the metallic surface. This protective film is attributed to the presence of nitrogen atoms and carbonyl group in the chemical structure of BAPA.
  18. Fulltext Coumarins as Potential Antioxidant Agents Complemented with Suggested Mechanisms and Approved by Molecular Modeling Studies
    Al-Majedy YK, Al-Duhaidahawi DL, Al-Azawi KF, Al-Amiery AA, Kadhum AA, Mohamad AB
    Molecules, 2016 Jan 23;21(2):135.
    PMID: 26805811 DOI: 10.3390/molecules21020135
    Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance). Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydrogen peroxide (H2O2). All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0 ± 5.0), followed by compounds 2 and 4 (88.0 ± 2.00; and 87.0 ± 3.00). Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00 ± 1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree-Fock-based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D) geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), to understand the antioxidant activity for the synthesized compounds.
  19. Fulltext Synthesis, inhibition effects and quantum chemical studies of a novel coumarin derivative on the corrosion of mild steel in a hydrochloric acid solution
    Al-Azawi KF, Al-Baghdadi SB, Mohamed AZ, Al-Amiery AA, Abed TK, Mohammed SA, et al.
    Chem Cent J, 2016;10:23.
    PMID: 27134648 DOI: 10.1186/s13065-016-0170-3
    BACKGROUND: The acid corrosion inhibition process of mild steel in 1 M HCl by 4-[(2-amino-1, 3, 4-thiadiazol-5-yl)methoxy]coumarin (ATC), has been investigated using weight loss technique and scanning electron microscopy (SEM). ATC was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared and nuclear magnetic resonance spectroscopy).

    FINDINGS: The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The adsorption equilibrium constant (K) and standard free energy of adsorption (ΔGads) were calculated. Quantum chemical parameters such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in both the EHOMO and μ values but with a decrease in the ELUMO value.

    CONCLUSIONS: Our research show that the synthesized macromolecule represents an excellent inhibitor for materials in acidic solutions. The efficiency of this macromolecule had maximum inhibition efficiency up to 96 % at 0.5 mM and diminishes with a higher temperature degree, which is revealing of chemical adsorption. An inhibitor molecule were absorbed by metal surface and follow Langmuir isotherms low and establishes an efficient macromolecule inhibitor having excellent inhibitive properties due to entity of S (sulfur) atom, N (nitrogen) atom and O (oxygen) atom.

  20. Fulltext Association of quality of life with internet use and weight stigma across individuals with obesity and those without obesity: Role of self-perception
    Lin CY, Latner JD, Rozzell-Voss KN, Huang PC, Tsai YC, Pakpour AH, et al.
    Acta Psychol (Amst), 2024 Apr;244:104203.
    PMID: 38442432 DOI: 10.1016/j.actpsy.2024.104203
    Weight status, weight stigma, and internet use are important factors impacting quality of life (QoL). However, little is known regarding how these factors interact in their association with QoL, and it is important to understand how self-perceived obesity and body mass index (BMI)-defined obesity may differentially impact QoL. We aimed to assess the associations between weight status (obesity vs. non-obesity, including both self-perceived and BMI-defined), weight stigma, internet use, and QoL. Cross-sectional data from the Taiwan Social Change Survey (N = 1604; mean age = 49.22; 52.93 % women) were used. All participants were classified as having obesity or not having obesity according to both self-perceived (self-perceived as 'too fat') and BMI-defined (≧27 kg/m2 as obesity) weight status. Results showed that the group with obesity (both BMI-defined and self-perceived) had significantly more internet time and lower physical QoL than the group without obesity. Those with self-perceived obesity, but not those with BMI-defined obesity, sought health information via the internet and used social media significantly more than the group without obesity. More internet time was associated with worse physical and mental QoL for the group with obesity regardless of BMI-defined or self-perceived status. Moreover, weight stigma was associated with worse mental QoL for the group with self-perceived obesity, but not for the group with BMI-defined obesity. Accordingly, being a person with obesity (self-defined, or based upon BMI) was associated with more internet time and poorer QoL. People with self-perceived obesity may have increased experience of weight stigma and greater internet use, factors that may contribute to their impaired QoL.
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