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Predicting a New Δ‐Proton Sponge‐Base of 4,12‐Dihydrogen‐4,8,12‐triazatriangulene through Proton Affinity, Aromatic Stabilization Energy, and Aromatic Magnetism
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Abstract<p>Herein, we report designing a new Δ (delta‐shaped) proton sponge base of 4,12‐dihydrogen‐4,8,12‐triazatriangulene (compound <bold>1</bold>) and calculating its proton affinity (<italic>PA</italic>), aromatic stabilization, natural bond orbital (NBO), electron density <italic>ρ</italic>(r), Laplacian of electron density ∇<sup>2</sup><italic>ρ</italic>(r), (2D‐3D) multidimensional <italic>off</italic>‐nucleus magnetic shielding (<italic>σ</italic><sub>zz</sub>(r) and <italic>σ</italic><sub>iso</sub>(r)), and scanning nucleus‐independent chemical shift (NICS<sub>zz</sub> and NICS). Density functional theory (DFT) at B3LYP/6‐311+G(d,p), ωB97XD/6‐311+G(d,p), and PW91/def2TZVP were used to compute the magnetic shielding variables. In addition, relevant bases like pyridine, quinoline, and acridine were also studied and compared. The protonation of compound <bold>1</bold> yields a highly symmetric carbocation of three Hückel benzenic rings. Comparing our findings of the studied molecules showed that compound <bold>1</bold> precedes others in <italic>PA</italic>, aromatic isomerization stabilization energy, and basicity. Therefore, the basicity may be enhanced when a conjugate acid gains higher aromatic features than its unprotonated base. Both multidimensional <italic>σ</italic><sub>zz</sub>(r) and <italic>σ</italic><sub>iso</sub>(r) <italic>off</italic>‐nucleus magnetic shieldings outperformed electron‐based techniques and can visually monitor changes in aromaticity that occur by protonation. The B3LYP/6‐311+G(d,p), ωB97XD/6‐311+G(d,p), and PW91/def2TZVP levels showed no significant differences in detailing isochemical shielding surfaces.</p>
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Publication Date
Wed Apr 01 2009
Journal Name
International Journal Of Applied Environmental Sciences
An expert System for Predicting the Effects of Noise Pollution on Grass Trimming Task Using Fuzzy Modeling
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Grass trimming operation is widely done in Malaysia for the purpose of maintaining highways. Large number of operators engaged in this work encounters high level of noise generated by back pack type grass trimmer used for this purpose. High level of noise exposure gives different kinds of ill effect on human operators. Exact nature of deteriorated work performance is not known. For predicting the work efficiency deterioration, fuzzy tool has been used in present research. It has been established that a fuzzy computing system will help in identification and analysis of fuzzy models fuzzy system offers a convenient way of representing the relationships between the inputs and outputs of a system in the form of IF-THEN rules. The paper presents

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Publication Date
Mon Feb 19 2024
Journal Name
Journal Of Engineering
Predicting Biochemical Oxygen Demand at the Inlet of Al-Rustumiya Wastewater Treatment Plant Using Different Mathematical Techniques
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Water quality planning relies on Biochemical Oxygen Demand BOD. BOD testing takes five days. The Particle Swarm Optimization (PSO) is increasingly used for water resource forecasting. This work designed a PSO technique for estimating everyday BOD at Al-Rustumiya wastewater treatment facility inlet. Al-Rustumiya wastewater treatment plant provided 702 plant-scale data sets during 2012-2022. The PSO model uses the daily data of the water quality parameters, including chemical oxygen demand (COD), chloride (Cl-), suspended solid (SS), total dissolved solids (TDS), and pH, to determine how each variable affects the daily incoming BOD. PSO and multiple linear regression (MLR) findings are compared, and their performance is evaluated usin

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Publication Date
Tue Dec 13 2022
Journal Name
Frontiers In Chemistry
Numerical analysis of the energy-storage performance of a PCM-based triplex-tube containment system equipped with arc-shaped fins
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This study numerically intends to evaluate the effects of arc-shaped fins on the melting capability of a triplex-tube confinement system filled with phase-change materials (PCMs). In contrast to situations with no fins, where PCM exhibits relatively poor heat response, in this study, the thermal performance is modified using novel arc-shaped fins with various circular angles and orientations compared with traditional rectangular fins. Several inline and staggered layouts are also assessed to maximize the fin’s efficacy. The effect of the nearby natural convection is further investigated by adding a fin to the bottom of the heat-storage domain. Additionally, the Reynolds number and temperature of the heat-transfer fluid (HTF) are e

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Publication Date
Sat Oct 08 2022
Journal Name
Journal Of Computational Design And Engineering
Twisted-fin parametric study to enhance the solidification performance of phase-change material in a shell-and-tube latent heat thermal energy storage system
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Abstract<p>Phase change material (PCM) is considered as one of the most effective thermal energy storage (TES) systems to balance energy supply and demand. A key challenge in designing efficient PCM-based TES systems lies in the enhancement of heat transmission during phase transition. This study numerically examines the privilege of employing twisted-fin arrays inside a shell-and-tube latent heat storage unit to improve the solidification performance. The presence of twisted fins contributes to the dominating role of heat conduction by their curved shapes, which restricts the role of natural convection but largely aids the overall heat-transfer process during solidification. The heat-discharge </p> ... Show More
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Publication Date
Thu Mar 20 2025
Journal Name
Tikrit Journal Of Engineering Sciences
Effect of Different Compressor Speeds on the Energy and Exergy of an Automobile Air-Conditioner Using R134a in the Absence and Presence of a Liquid-Suction Heat Exchanger
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Refrigerant R134a has been widely utilized in automotive air conditioning systems (AACSs); R134a has a high global warming potential (GWP) of 1430 despite having zero ozone depletion potential (ODP). Coming refrigeration systems must include refrigerants with low GWP and zero ODP. The aim of this experimental study is to evaluate the thermal performance of an (AAC) with different values of compressor speeds, i.e., (1000, 1700, and 2400 rpm) and two thermal loads, i.e., (500 and 1000 Watt) with the absence and presence of liquid suction heat exchanger (LSHX) using R134a. The results showed that adding LSHX enhanced the COP cycle by 7.18%, 10.7%, and 3.09% for the first, second, and third speed, respectively, at 500 Watt, while the en

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Publication Date
Fri Apr 21 2023
Journal Name
Chemical Methodologies
Spectroscopic and Antimicrobial Studies of Some Metal Complexes of Furfural Schiff Base Derivative Ligand
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A new furfural Schiff base derivative ligand (L-FSB) named N-(4- Bromo-2-methylphenyl)-1-(furan-2-yl)methanimine, was synthesized from the condensation reaction of furfural (fur) with 4-Bromo-2- methylaniline (bma) in 1:1molar ratio. A new series of VO(II), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) metal complexes are synthesized according to the metal content analysis in an 2:1 ligand:metal ratio. The stereochemistry of the ligand complexes have been deduced by Fourier Transform-Infra Red (FT-IR), Atomic Adsorption (A.A), Ultra violate-Visible Spectra (UV-Vis Spectra), (Mass Spectra, Proton,13Carbon-Nuclear Magnetic Resonance) (1H-NMR,13CNMR) for ligand), magnetic susceptibility at 25oC and conductivity measurements. Fr

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Publication Date
Tue Jan 18 2022
Journal Name
Materials Science Forum
Effect Partial Substitution of Calcium by &lt;i&gt;Cadmium&lt;/i&gt; on Dielectrically Properties of Li0.4Cd0.6Ba2Ca2Cu3O10+δ System
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In this article the conventional "solid-state reaction" method was used to synthesize perovskite Li0.4Cd0.6Ba2Ca2Cu3O10+δ. Four main types of compounds were obtained by physically replacing calcium oxide with cadmium in proportions 0, 0.03, 0.06 and 0.09, the pure Li0.4Cd0.6Ba2Ca2Cu3O10+δ phase, and the phases Li0.4Cd0.6Ba2Ca1.97Cd0.03Cu3O10+δ

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Publication Date
Mon Jun 19 2017
Journal Name
Arabian Journal For Science And Engineering
A New Method to Tune a Fractional-Order PID Controller for a Twin Rotor Aerodynamic System
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Publication Date
Wed Apr 14 2021
Journal Name
Wireless Personal Communications
A Partial CSI Estimation Approach for Downlink FDD massive-MIMO System with Different Base Transceiver Station Topologies
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Massive multiple-input multiple-output (massive-MIMO) is a promising technology for next generation wireless communications systems due to its capability to increase the data rate and meet the enormous ongoing data traffic explosion. However, in non-reciprocal channels, such as those encountered in frequency division duplex (FDD) systems, channel state information (CSI) estimation using downlink (DL) training sequence is to date very challenging issue, especially when the channel exhibits a shorter coherence time. In particular, the availability of sufficiently accurate CSI at the base transceiver station (BTS) allows an efficient precoding design in the DL transmission to be achieved, and thus, reliable communication systems can be obtaine

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Publication Date
Thu May 02 2013
Journal Name
Diyala Journal For Pure Sciences
Synthesis and Characterization of Mixed Ligands of Dithizone and Schiff Base Complexes with Selected Metal Ions.
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Salicylaldehyde was react with 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-on to produce the Schiff base ligand 2,3-dimethyl-1-phenyl-4-salicylidene-3-pyrazoline-5-on (L). The prepared ligand was identified by Microelemental Analysis, and FT.IR, UV-Vis spectroscopic techniques. A new complexes of Fe(III),Co(II),Ni(II),Cu(II),Ce(III) and Pb(II) with mixed ligands of dithizone (DTZ) and Schiff base were prepared in aqueous ethanol with a 2:2:1 M:L:DTZ. The prepared complexes were characterized using flame atomic absorption, (C.H.N) Analysis, FT.IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements. In addition biological activity of the ligands and complexes against two selected type of bacteria

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