An evidence for an organic N-doped multiwall carbon nanotube heterostructure and its superior electrocatalytic properties for promising dye-sensitized solar cells

Arbab, Alvira Ayoub,Memon, Anam Ali,Sahito, Iftikhar Ali,Mengal, Naveed,Sun, Kyung Chul,Ali, Mumtaz,Jeong, Sung Hoon The Royal Society of Chemistry 2018 Journal of materials chemistry. A, Materials for e Vol.6 No.18

<P>A novel organic heteroatom doping technique is proposed for the synthesis of N-doped multiwall carbon nanotube (MWCNT) heterostructures. The approach involves the effective doping of MWCNTs with nitrogen <I>via</I> a cationised bovine serum albumin (cBSA) protein complex. The cationization of BSA releases an exceptional number of activated nitrogen species present in localized amino groups, which are further embedded into the MWCNT framework. The amino groups present in BSA act as nitrogen donors and surface stabilizing agents to generate a highly conductive and functionalized carbon heterostructure. The doped nitrogen was present in the form of pyridinic and pyrrolic states, as evidenced by XPS analysis. Organic N-doped MWCNTs with predominant pyridinic N atoms displayed superior charge transfer (<I>R</I>CT = 0.06 Ω) owing to their superior electrocatalytic activity. A DSSC fabricated with organic N-doped MWCNT heterostructures exhibited a high conversion efficiency of 9.55%, which was similar to that of a Pt cathode, with an efficiency of 9.89%. The superior electrochemical performance of organic N-doped MWCNT heterostructures is due to the high charge polarization arising from the difference in electronegativity between nitrogen and carbon as well as the structural strain caused by the cationic BSA protein complex. Our proposed system provides new routes for the synthesis of organic heteroatom-doped nanomaterials for promising energy storage devices.</P>

Effect of sodium butyrate on performance, immune status, microarchitecture of small intestinal mucosa and lymphoid organs in broiler chickens

Arbab Sikandar,Hafsa Zaneb,Muhammad Younus,Saima Masood,Asim Aslam,Farina Khattak,Saima Ashraf,Muhammad Shahbaz Yousaf,Habib Rehman 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.5

Objective: This study aimed to examine the effect of sodium butyrate (SB) on growth performance, immune status, organs weights, and microarchitecture of lymphoid organs and small intestine. Methods: A total of 120, 1-d-old broiler chicks were distributed into the following four treatment groups: corn-soy based basal diet (BD) without supplement (control), or the same BD supplemented with 0.1 g/kg zinc bacitracin (ZnB), 0.5 g/kg SB (SB-0.5), or 1.0 g/kg SB (SB-1), respectively. Six birds/group were killed on d-21 and d-35, and samples were collected. Results: Cell-mediated immune response at 48 h post-Phytohemagglutinin-P injection, and antibody titer against Newcastle disease vaccine and sheep red blood cells on d-35 was noted higher (p<0.05) in SB-1 compared to ZnB and control. Lower (p<0.05) feed conversion ratio (FCR) was attained by the supplemented groups. Thymus and spleen weighed more (p<0.05) in SB-1, and bursa registered more (p<0.05) weight in both SB groups compared to control. On d-21, areas of thymus medulla and spleen germinal centers were noted higher (p<0.05) in SB-1 group. The villus height and villus surface area increased (p<0.05) in duodenum and jejunum in both SB groups on d-21, and in SB-1 on d-35, respectively compared to ZnB and control. On d-21, number of goblet cells containing mucins of acidic nature increased (p<0.05) in all the segments of small intestines in SB-1 group compared to control, and on d-35 in ileum compared to other groups. Conclusion: In conclusion, SB improved growth performance and immunity as well as modulated morphology of lymphoid organs and gut mucosa in broiler chickens.

An organic route for the synthesis of cationic porous graphite nanomaterial used as photocatalyst and electrocatalyst for dye-sensitized solar cell

Arbab, Alvira Ayoub,Mengal, Naveed,Sahito, Iftikhar Ali,Memon, Anam Ali,Jeong, Sung Hoon Elsevier 2018 ELECTROCHIMICA ACTA Vol.266 No.-

<P><B>Abstract</B></P> <P>An organic synthesis route is proposed to fabricate cationized porous graphite (cpG) for photocatalyst and electrocatalyst nanomaterial. High crystalline structure of graphite possesses few defects and porous channels. In the proposed research, cpG is fabricated by sonicating graphite in cationized enzyme media followed by exfoliating in the activated charcoal filler. The cationic lipase solution distributed positive surface charges over a bare graphitic sheet, and sonication with activated charcoal filler divulges porous channels along graphite exfoliated matrix structure. The charcoal doping in graphite was modified with the different charcoal content percentage ranging from 0 to 100%. The cationized porous graphite (cpG) material possess high surface area, pore volume and conductivity leads to high photoresponse and electrocatalytic reaction. As photocatalyst, the proposed graphite provide fast degradation of methylene blue dye observed by UV–Vis spectrophotometer. As cathode for dye-sensitized solar cell (DSSCs), cpG provides high electrocatalytic activity with low charge transfer resistance (R<SUB>CT</SUB> = 0.95Ω) and high photovoltaic performance with 9.59% efficiency. The positive charge distribution over graphite sheet attracts plenty of negative iodide ions present in the electrolyte, provide fast reduction-oxidation reaction. Furthermore, porous charcoal filler doping accepts a large amount of gel electrolyte, and fasten interfacial reaction between electrolyte and CE. This cost-effective cationized porous graphite (cpG) nanomaterial can provide new ways towards sustainable energy resources.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An organic route for the synthesis of cationized porous graphite (cpG) nanomaterial is proposed. </LI> <LI> cpG used as photo catalyst and electro catalyst for DSSCs. </LI> <LI> cpG shows excellent degradation of methylene blue dye at very low time interval. </LI> <LI> cpG demonstrated low R<SUB>CT</SUB> of 0.95Ω with high photovoltaic performance. </LI> <LI> cpG cathode outperform Pt. electrode and exhibit 9.59% PCE of DSSCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Spatial distribution and sequential sampling plans for adult Sitona humeralis Stephens (Coleoptera: Curculionidae) in alfalfa

A. Arbab,M.R.McNeill 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

The spatio-temporal distribution of adult Sitona humeralis Stephens (Coleoptera: Curculionidae), a key pest of alfalfa,was studied using sweep netting for two years in alfalfa fields. The first objective was to analyze the distributionof this insect within alfalfa and the second objectivewas to develop sampling plans based on fixed levels ofprecision for estimating S. humeralis adult populations. The following models were used to analyze the data:Taylor's power law and Iwao's patchiness regression. Our results document that in both years, Iwao's patchinessprovided a better description between variance and mean density. Taylor's b and Iwao's β were both significantlyN1, indicating that adults had aggregated spatial distribution. Iwao's α was significantly b0, indicating that thebasic distribution component of S. humeralis is the individual insect. Optimal sample sizes for fixed precisionlevels of 0.10 and 0.25 were estimated. The optimum sample size fluctuated throughout the seasons anddepended upon the weevil density and desired level of precision. This generally ranged from 3 to 7 × 15 sweepsand 16 to 46 × 15 sweeps to achieve precision levels of 0.25 and 0.10, respectively. With respect to the optimumsample size, the developed fixed-precision sequential sampling plans were suitable for estimatingweevil densityat a precision level of D= 0.25. The sampling plan presented here provides a tool for research on pest managementdecisions of S. humeralis.

Nonwoven Polyethylene Terephthalate Paper Loaded with Enzyme Coupled Multiwall Carbon Nanotubes for Superior Photocatalytic Activity for Water Remediation

Alvira Ayoub Arbab,Rabia Almas Arain,Raja Fahad Qureshi,Iftikhar Ali Sahito,선경철,정성훈 한국섬유공학회 2019 Fibers and polymers Vol.20 No.4

A highly photocatalytic, carbon coated nonwoven polyethylene terephthalate paper (CCPETP) is developed byusing the wet-laid method for photodegradation of dye effluents from the textile wastewater treatment. The designednonwoven PET paper is coated with Multiwall walled carbon nanotubes (MWCNT) catalyst coupled with cationised enzymeagent. Three different types of enzymatic coupling agents were used i.e. Lipase, Glucose oxidase, and Laccase, respectively. Enzymes are generally globular proteins, packed with amino complex N-terminals, oxygenated amines and hydroxyl atoms. The sequence of the amino acids specifies the structure which in turn determines the catalytic activity of the enzyme. Thecationization of the enzyme under acidic condition (~pH 3), detach the amino/oxygen complex structure from their corestructure and encapsulate over MWCNT surface. The coupled enzyme dissipates functional oxygenated amines, pyrrolic,pyridinic, graphitic and quaternary type of nitrogen contents. The attachment of functionalized surface groups withoutforming any defect-rich vacancy promotes efficient charge generation and photocatalytic degradation of methylene blue dye(MB) particulates. Besides, the suggested low-cost porous PET nonwoven paper helps to absorb a large number of dyemolecules for efficient dye degradation. The excellent photocatalytic activity of the proposed thin CCPETP photocatalyst ismainly attributed to its specific coupled enzyme, high adsorbing capacity of PET paper, and low recombination of thephotogenerated electrons and holes. The optimal loading content of enzyme coupled MWCNT over nonwoven PET paperdecolorized ~99.0 % methylene blue (MB) dye in 100 min. The excellent dye degradation efficiency of this low-cost materialis attributed its surface characteristics and high absorbing properties. The synergistic effect of cluster active sites and thefunctional amine/oxygen surface groups promoting the generation of ˙OH ions for MB degradation. The fabricatednonwoven paper is expected for large industrial applications and will provide a generic route towards the fabrication of textilestructured photocatalyst.

Comparison of the cyclic fatigue resistance of One Curve, F6 Skytaper, Protaper Next, and Hyflex CM endodontic files

Gouédard Charlotte,Pino Laurent,Arbab-Chirani Reza,Arbab-Chirani Shabnam,Chevalier Valérie 대한치과보존학회 2022 Restorative Dentistry & Endodontics Vol.47 No.2

Objectives This study compared the cyclic fatigue resistance of One Curve (C wire) and F6 Skytaper (conventional austenite nickel-titanium [NiTi]), and 2 instruments with thermo-mechanically treated NiTi: Protaper Next X2 (M wire) and Hyflex CM (CM wire). Materials and Methods Ten new instruments of each group (size: 0.25 mm, 6% taper in the 3 mm tip region) were tested using a rotary bending machine with a 60° curvature angle and a 5 mm curvature radius, at room temperature. The number of cycles until fracture was recorded. The length of the fractured instruments was measured. The fracture surface of each fragment was examined with a scanning electron microscope (SEM). The data were analyzed using one-way analysis of variance and the post hoc Tukey test. The significance level was set at 0.05. Results At 60°, One Curve, F6 Skytaper and Hyflex CM had significantly longer fatigue lives than Protaper Next X2 (p < 0.05). No statistically significant differences were found in the cyclic fatigue lives of One Curve, F6 Skytaper, and Hyflex CM (p > 0.05). SEM images of the fracture surfaces of the different instruments showed typical features of fatigue failure. Conclusions Within the conditions of this study, at 60° and with a 5 mm curvature radius, the cyclic fatigue life of One Curve was not significantly different from those of F6 Skytaper and Hyflex CM. The cyclic fatigue lives of these 3 instruments were statistically significantly longer than that of Protaper Next. Objectives This study compared the cyclic fatigue resistance of One Curve (C wire) and F6 Skytaper (conventional austenite nickel-titanium [NiTi]), and 2 instruments with thermo-mechanically treated NiTi: Protaper Next X2 (M wire) and Hyflex CM (CM wire). Materials and Methods Ten new instruments of each group (size: 0.25 mm, 6% taper in the 3 mm tip region) were tested using a rotary bending machine with a 60° curvature angle and a 5 mm curvature radius, at room temperature. The number of cycles until fracture was recorded. The length of the fractured instruments was measured. The fracture surface of each fragment was examined with a scanning electron microscope (SEM). The data were analyzed using one-way analysis of variance and the post hoc Tukey test. The significance level was set at 0.05. Results At 60°, One Curve, F6 Skytaper and Hyflex CM had significantly longer fatigue lives than Protaper Next X2 (p < 0.05). No statistically significant differences were found in the cyclic fatigue lives of One Curve, F6 Skytaper, and Hyflex CM (p > 0.05). SEM images of the fracture surfaces of the different instruments showed typical features of fatigue failure. Conclusions Within the conditions of this study, at 60° and with a 5 mm curvature radius, the cyclic fatigue life of One Curve was not significantly different from those of F6 Skytaper and Hyflex CM. The cyclic fatigue lives of these 3 instruments were statistically significantly longer than that of Protaper Next.

An electrocatalytic active lyocell fabric cathode based on cationically functionalized and charcoal decorated graphite composite for quasi-solid state dye sensitized solar cell

Mengal, Naveed,Arbab, Alvira Ayoub,Sahito, Iftikhar Ali,Memon, Anam Ali,Sun, Kyung Chul,Jeong, Sung Hoon Elsevier 2017 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.155 No.-

<P><B>Abstract</B></P> <P>The state of the art of conductive functional textile woven fabrics have given rise to a demand for textile integrated electrodes. Herein, we report a highly conductive and flexible woven fabric electrode using highly absorbent lyocell fabric as the substrate and cationically functionalized and activated charcoal decorated graphite composite (AC-GC) as the coating film. This (AC-GC) coated lyocell fabric is used as a cathode for quasi-solid state dye sensitized solar cell (Q-DSSCs). Our suggested fabric based cathode shows sufficiently high conductivity and electrocatalytic activity (ECA) compared to platinum (Pt) based reference counter electrode (CE). This efficient CE demonstrates extremely low charge transfer resistance (R<SUB>CT</SUB>) of 1.56Ωcm<SUP>2</SUP> with polyethylene oxide based quasi-solid electrolyte. The cationic charged enriched charcoal decorated graphite planner structure provide more availability of active sites for the reduction of negatively charged tri-iodide ( I 3 - ) ions present in polymeric gel electrolyte. The formation of porous charcoal voids and conductive graphite channels entrap large amounts of gel electrolyte and provide fast diffusion of iodide/tri-iodide ( <SUP> I - </SUP> / I 3 - ) ions. Our organic system of AC-GC coated lyocell fabric based DSSCs assembly demonstrated 7.09% power conversion efficiency (PCE) when fabricated with quasi-solid electrolyte. This AC-GC coated fabric CE is also highly stable in water and electrolyte solution. The adequate electrocatalytic activity and cyclic stability demonstrate that this AC-GC coated fabric can be used to replace expensive Pt CE and can be used in flexible solar cells in future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Various composites of activated charcoal and enzyme functionalized graphite (AC-GC) were prepared by a facile route. </LI> <LI> Highly porous and electrocatalytic AC-GC coatings were applied on lyocell fabric for preparation of flexible electrode. </LI> <LI> The flexible electrodes showed high stability in water and lithium iodide based electrolyte. </LI> <LI> DSSC based on optimized flexible electrode demonstrated maximum power conversion efficiency of 7.09%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Cationic functionalized and activated charcoal decorated graphite coated lyocell fabric cathode is Q-DSSCs, displayed 7.1% efficiency.</P> <P>[DISPLAY OMISSION]</P>

Design of Multivariable PID Controllers: A Comparative Study

Memon, Shabeena,Kalhoro, Arbab Nighat International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.8

The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

Design of Multivariable PID Controllers: A Comparative Study

Memon, Shabeena,Kalhoro, Arbab Nighat International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.9

The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

Spindle Speed Optimization of a Ring Spinning Machine for Better Surface Irregularity and Hairiness of Yarn and Fabric

정성훈,Sahito, Iftikhar Ali,Arbab, Alvira Ayoub,Jeong, Sung Hoon 한국섬유공학회 2015 한국섬유공학회지 Vol.52 No.1

Producing yarn from natural fibers without creating irregularities in structure or having fibers protruding from the surface, remains the goal of spinners. This is a problem, as structural irregularities such as hairiness affect subsequent fabric manufacturing processes and the aesthetics of the final fabric. This work therefore focused on investigating the effects of varying the spindle speed of a ring spinning frame on the structure of yarn (i.e., its surface regularity and hairiness), its strength and the surface pilling of fabric made from such yarn with a view to optimizing the spindle speed. For this, yarns with counts of 20, 25, and 30 tex were produced at six different spindle speeds ranging from 11,000 to 21,000 rpm with an interval of 2,000 rpm. All other parameters were kept constant, including the draft for a particular count, the type and weight of the traveler, and the diameter of the ring. The results obtained revealed that as the spindle speed was increased to 17,000 rpm, the yarn structure became more regular and less hairy, thereby becoming stronger. Beyond 17,000 rpm, however, both the regularity and strength decreased, with the hairiness continuing to increase with increasing spindle speed. Consequently, the surface pilling of the fabric was found to be optimized when made from yarns produced at a spindle speed of 17,000 rpm.