Sensitive and selective m-tolyl hydrazine chemical sensor development based on CdO nanomaterial decorated multi-walled carbon nanotubes

Mohammed M. Rahman,M.M. Alam,Khalid A. Alamry 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

In this approach, the wet-chemical (co-precipitation) technique was used to prepare the cadmium oxide(CdO) nanoparticles (NPs) decorated with multi-walled carbon nanotubes (CNT) at low temperature. Thepowder XDR, UV–vis, TEM, XPS, and FTIR spectroscopy were used for detail characterization of thesynthesized CdO/CNT nanocomposite (NCs). A thin layer of CdO/CNT NCs was deposited onto a glassycarbon electrode (GCE) with conducting coating binder to obtain a chemical sensor which wassubsequently used to detect m-tolyl hydrazine hydrochloride (m-THyd) in buffer medium byelectrochemical approach for environmental safety. The proposed m-THyd chemical sensor exhibitedlong-term stability, good selectivity, broad linear dynamic range, lower detection limit, and enhancedelectrochemical response. The calibration curve of the current vs concentration of m-THyd was found tobe linear (r2 = 0.9903) over the linear dynamic range (LDR) of 0.01 nM to 0.1 mM. The sensitivity(25.7911 mA mM cm 2) of chemical sensor was calculated from the slope of calibration curve and surfacearea of GCE (0.0316 cm2) and the detection limit (4.0 0.2 pM) was estimated from the signal to noiseratio at 3. These preliminary results suggest that the newly developed CdO/CNT NCs nanocompositecould be promising electrochemical sensors for the detection of hazardous toxins to clean theenvironment in broad scales.

Structure-based magnetic, electrical and transport properties of Ni–Zn–Co ferrite by V5+ substitution

Hossain M.D.,Khan M.N.I.,Hossain Md Sarowar,Ahned S.J.,Alam M.K.,Liba S.I.,Hakim M.A.,Jamil A.T.M.K. 한국물리학회 2022 Current Applied Physics Vol.43 No.-

This article presents the modification of structure-based magnetic, electronic and transport properties along with the conduction mechanism and its relaxation process in a Ni–Zn–Co ferrite tailored by V5+ substitution at B-site replacing Fe3+ ions. The composition Ni0.7Zn0.2Co0.1Fe2-xVxO4 (0≤ x≤ 0.12) was synthesized by standard solid-state reaction method and all samples were crystallized with a single-phase cubic spinel structure belonging to the Fd3m space group. The lattice constants decreased gradually from 8.3673≽A to 8.3602≽A and the average grain sizes (DSEM) are also decreased from 6.92 μm to 1.99 μm due to V5+ ions substitution at Fe3+ of B-site. However, more than 25% of Fe3+ ions migrate to A-site from B-site due to V5+ substitution at Fe3+ of B-site. In all samples θD does not strictly follow the Anderson’s prediction, rather it monotonically decreases to a low value until x = 0.12. Magnetic phase transition temperature shifted to the lower temperature and the net magnetization (ηeB) decreases due to V5+ substitution in Ni–Zn–Co ferrite. Apart this, during conduction charge carriers should require more energy to jump from one cationic site to other for V5+ substitution in the Ni–Zn–Co ferrite and the activation energy (Ea) is much more higher in V5+ substituted sample. Moreover, long-range interaction with localized relaxation mechanism is observed in V5+ doped samples. The resistance at the grain (Rg) is maximum (243.09 Ω) for the sample x = 0.10 while grain boundary resistance (Rgb) is maximum (5.98×105 Ω) for the sample x = 0.07. However, the higher value of ρdC for x = 0.12 sample ensures to be suitable for electromagnets, transformers, electronic inductors, and at high-frequency applications. Moreover, x = 0.07 sample displays high value of TCR ( -8.6%/K at 418 K) which may be utilized as an infrared detector for night vision bolometer material.

Synthesis of Tetrazolo[1,5-a]quinoxaline based Azetidinones & Thiazolidinones as Potent Antibacterial & Antifungal Agents

Kumar, Shiv,Khan, S.A.,Alam, Ozair,Azim, Rizwan,Khurana, Atul,Shaquiquzzaman, M.,Siddiqui, Nadeem,Ahsan, Waquar Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

4-Chlorotetrazolo[1,5-a]quinoxaline (III) was synthesized by azide (2+3) cycloaddition of 2,3-dichloroquinoxaline (II). Compound (III) on further refluxing with hydrazine hydrate furnished 4-hydrazinotetrazolo[1,5-a]quinoxaline (IV). Further refluxing of (IV) with different aromatic aldehydes in methanol yielded corresponding Schiff's bases V(a-j). Various 4-aminotetrazolo[1,5-a]quinoxaline based azetidinones VII(a-j) were synthesized by stirring the compounds V(a-j), at low temperature, with equimolar mixture of chloroacetylchloride & triethylamine in dry benzene, while 4-aminotetrazolo[1,5-a]quinoxaline based thiazolidinones VIII(a-j) were synthesized by refluxing Schiff's bases V(a-j) with thioglycolic acid in oil-bath. The structures of all the compounds were confirmed on the basis of $^1H$-NMR & FT-IR spectral data. All the newly synthesized compounds were screened for in-vitro antimicrobial activity against E. coli, S. aureus, K. pneumoniae & P. aeruginosa & antifungal activity against C. albicans. Few of them have exhibited the promising activity.

Synthesis of Tetrazolo[1,5-a]quinoxaline based Azetidinones & Thiazolidinones as Potent Antibacterial & Antifungal Agents

Shiv Kumar,S. A. Khan,Ozair Alam,Rizwan Azim,Atul Khurana,M. Shaquiquzzaman,Nadeem Siddiqui,Waquar Ahsan 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

4-Chlorotetrazolo[1,5-a]quinoxaline (III) was synthesized by azide (2+3) cycloaddition of 2,3-dichloroquinoxaline (II). Compound (III) on further refluxing with hydrazine hydrate furnished 4-hydrazinotetrazolo[1,5-a]quinoxaline (IV). Further refluxing of (IV) with different aromatic aldehydes in methanol yielded corresponding Schiff’s bases V(a-j). Various 4-aminotetrazolo[1,5-a]quinoxaline based azetidinones VII(a-j) were synthesized by stirring the compounds V(a-j), at low temperature, with equimolar mixture of chloroacetylchloride & triethylamine in dry benzene, while 4-aminotetrazolo[1,5-a]quinoxaline based thiazolidinones VIII(a-j) were synthesized by refluxing Schiff’s bases V(a-j) with thioglycolic acid in oil-bath. The structures of all the compounds were confirmed on the basis of ^1H-NMR & FT-IR spectral data. All the newly synthesized compounds were screened for in-vitro antimicrobial activity against E. coli, S. aureus, K. pneumoniae & P. aeruginosa & antifungal activity against C. albicans. Few of them have exhibited the promising activity.

THE COST OF SEMEN PRODUCTION AND THE RATE OF CONCEPTION FOR ARTIFICIAL INSEMINATION IN CATTLE

Alam, J.,Akteruzzaman, M.,Rahman, A.,Sayeed, M.A. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.1

This study was conducted to determine the cost of production of semen and the rate of conception for artificial insemination in eight randomly selected districts of Bangladesh. A sample of 640 adopting farms were investigated. Results indicate that the cost of liquid semen per dose on full-cost and cash cast basis were Tk. 16.17 and Tk. 14.48, while the cost of locally produced exotic semen and imported semen were Tk. 31.25 and Tk. 110.00 respectively. The cost of liquid semen per insemination, per conception and per progeny on full-cost were Tk. 26.65, Tk. 50.64, and Tk. 56.27 respectively and on cash cost were Tk. 23.88, Tk. 45.37 and Tk. 50.41 respectively. The average cost of semen paid by the farmers was Tk. 14.00 and it was higher in urban areas than in rural areas. Out of the cost of A.I. centres, government had subsidized 92.16 percent and the rest 7.84 percent accrued as returns. About 40 percent of the produced semen was lost in the system which could not be used at all. The conception rate on first insemination was 53.6 percent. The rate increased to 73.2 percent upto the last insemination. The difference in conception rate between liquid semen (69.97%) and frozen semen (70.48%) was not statistically significant.

Secure Mobile Commerce in Ad hoc Network Using CAEC2M

Khaleel Ahmad,Md Shoaib Alam,M A Rizvi 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.12

M-Commerce applications in the world have grown exponentially over the years. It had set up for mobile users to engage wirelessly of ad hoc network infrastructure in online business irrespective of place or time. Providing anonymous, secure and trust based connection service in ad hoc network is quite a challenging task. Anonymity, security and privacy of the transaction or message transmission are the highest priority need to be delivered to the destination node on time. In this paper, a CAEC2M (Cellular Automata Elliptic Curve Cryptography Mix network) algorithm to secure Mobile Commerce over ad hoc network is proposed. An attempt is made to design a mix-network (Mix-Net) using elliptic curve cryptography based on cellular automata which creates a hard to trace communication to protect the anonymity of the sender and encrypt the sensitive information to avoid any eavesdropper trying to access the data during transmission. CAEC2M provides also confidentiality, integrity and authentication.

Seismic behaviour of repaired superelastic shape memory alloy reinforced concrete beam-column joint

Nehdi, Moncef,Alam, M. Shahria,Youssef, Maged A. Techno-Press 2011 Smart Structures and Systems, An International Jou Vol.7 No.5

Large-scale earthquakes pose serious threats to infrastructure causing substantial damage and large residual deformations. Superelastic (SE) Shape-Memory-Alloys (SMAs) are unique alloys with the ability to undergo large deformations, but can recover its original shape upon stress removal. The purpose of this research is to exploit this characteristic of SMAs such that concrete Beam-Column Joints (BCJs) reinforced with SMA bars at the plastic hinge region experience reduced residual deformation at the end of earthquakes. Another objective is to evaluate the seismic performance of SMA Reinforced Concrete BCJs repaired with flowable Structural-Repair-Concrete (SRC). A $\frac{3}{4}$-scale BCJ reinforced with SMA rebars in the plastic-hinge zone was tested under reversed cyclic loading, and subsequently repaired and retested. The joint was selected from an RC building located in the seismic region of western Canada. It was designed and detailed according to the NBCC 2005 and CSA A23.3-04 recommendations. The behaviour under reversed cyclic loading of the original and repaired joints, their load-storey drift, and energy dissipation ability were compared. The results demonstrate that SMA-RC BCJs are able to recover nearly all of their post-yield deformation, requiring a minimum amount of repair, even after a large earthquake, proving to be smart structural elements. It was also shown that the use of SRC to repair damaged BCJs can restore its full capacity.

Seismic behaviour of repaired superelastic shape memory alloy reinforced concrete beam-column joint

Moncef Nehdi,M. Shahria Alam,Maged A. Youssef 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.7 No.5

Large-scale earthquakes pose serious threats to infrastructure causing substantial damage and large residual deformations. Superelastic (SE) Shape-Memory-Alloys (SMAs) are unique alloys with the ability to undergo large deformations, but can recover its original shape upon stress removal. The purpose of this research is to exploit this characteristic of SMAs such that concrete Beam-Column Joints (BCJs) reinforced with SMA bars at the plastic hinge region experience reduced residual deformation at the end of earthquakes. Another objective is to evaluate the seismic performance of SMA Reinforced Concrete BCJs repaired with flowable Structural-Repair-Concrete (SRC). A ¾-scale BCJ reinforced with SMA rebars in the plastic-hinge zone was tested under reversed cyclic loading, and subsequently repaired and retested. The joint was selected from an RC building located in the seismic region of western Canada. It was designed and detailed according to the NBCC 2005 and CSA A23.3-04 recommendations. The behaviour under reversed cyclic loading of the original and repaired joints, their load-storey drift, and energy dissipation ability were compared. The results demonstrate that SMA-RC BCJs are able to recover nearly all of their post-yield deformation, requiring a minimum amount of repair, even after a large earthquake, proving to be smart structural elements. It was also shown that the use of SRC to repair damaged BCJs can restore its full capacity.

Effects of sintering temperature and zirconia content on the mechanical and microstructural properties of MgO, TiO2 and CeO2 doped alumina–zirconia (ZTA) ceramic

Al-Amin Md.,Mumu Homayra Tabassum,Sarker Saugata,Alam Md. Zahangir,Gafur M. A. 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.1

The effects of sintering temperature and ZrO2 addition on the hardness and fracture toughness of zirconia toughened alumina (ZTA)–MgO–TiO2 composite was investigated. 5 wt.% CeO2 was added to ZTA containing 5 wt.% of MgO and 5 wt.% of TiO2. Two sets of composition A5ZMTC and A15ZMTC were used consisting of 5 wt.% and 15 wt.% of 3YSZ, respectively, to analyze the effect of CeO2 on the base composition. The powders were pressed into pellets and sintered at different temperatures of 1450 °C, 1500 °C, 1600 °C and 1650 °C for 3 h. Density, hardness and fracture toughness increased to a maximum value and then decreased. From the XRD analysis, Ce0.7Zr0.3O2 in only A5ZMTC and CeAl11O18 in only A15ZMTC are evident. The highest fracture toughness of 12.03 MPam1/2 (Casellas) was achieved at 1500 °C in A15ZMTC and maximum hardness of 14.15 GPa was obtained in A5ZMTC sintered at 1450 °C.

Effect of Tannins in Acacia nilotica, Albizia procera and Sesbania acculeata Foliage Determined In vitro, In sacco, and In vivo

Alam, M.R.,Amin, M.R.,Kabir, A.K.M.A.,Moniruzzaman, M.,McNeill, D.M. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.2

The nutritive value and the effect of tannins on the utilization of foliage from three commonly used legumes, Acacia nilotica, Albizia procera, and Sesbania acculeata, were determined. Three mature rumen-fistulated bullocks were used to study in sacco degradability and twelve adult sheep were randomly allocated on the basis of live weight to 4 groups of 3 in each to study the in vivo digestibility of the foliages. In all foliages, the contents of crude protein (17 to 24% of DM) were high. Fibre was especially high in Albizia (NDF 58.8% of DM vs. 21% in Sesbania and 15.4% in Acacia). Contents of both hydrolysable (4.4 to 0.05%) and condensed tannins (1.2 to 0.04%) varied from medium to low in the foliages. Acacia contained the highest level of total phenolics (20.1%), protein precipitable phenolics (13.2%) and had the highest capacity to precipitate protein (14.7%). Drying in shade reduced the tannin content in Acacia and Albizia by 48.6 and 69.3% respectively. The foliages ranked similarly for each of the different methods used to estimate tannin content and activity. Acacia and Sesbania foliage was highly degradable (85-87% potential degradability of DM in sacco), compared to Albizia (52%), indicating a minimal effect of tannins in Acacia and Sesbania. Yet, in vitro, the tannins in the Acacia inhibited microbial activity more than those in Albizia and Sesbania. Following the addition of polyethylene glycol to neutralise the tannins, gas production and microbial growth increased by 59% and 0.09 mg RNA equiv./dg microbial yield respectively in the Acacia, compared to 16-17% and 0.06 mg RNA equiv./dg microbial yield in the other foliages. There was a trend for low in vivo apparent digestibility of N in the Acacia (43.2%) and Albizia (44.2%) compared to the Sesbania (54.5%) supplemented groups. This was likely to be due to presence of tannins. Consistent with this was the low N retention (0.22 and 0.19 g N/g NI) in sheep supplemented with Acacia and Albizia compared to that for the Sesbania (0.32). Similarly, a trend for poor microbial N yield was observed in sheep fed these foliages. Across the foliages tested, an increase in tannin content was associated with a reduction in ruminal fermentation, N digestibility and N retention. For overall nutritive value, Sesbania proved to be the superior forage of the three tested.