Experimental and Numerical Analyses of the Effects of Overload on the Fatigue Life of Aluminum Alloy Panels Repaired with Bonded Composite Patch

N. H. M. Bouchkara,Abdulmohsen Albedah,Faycal Benyahia,Sohail M. A. Khan Mohammed,Bel Abbes Bachir Bouiadjra 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.5

In this study, we analyzed the effect of a single overload fatigue cycle on the efficiency of bonded composite patch repair on a cracked Al 2024 T3 aluminum plate. Experimental and numerical analyses were performed to achieve the objective of the study. In the experimental part of the study, fatigue tests were conducted on a V-notched aluminum plate subjected to a constant amplitude fatigue loading with an overload applied at a relative crack length of 0.06 (a/W = 0.06). The plate was repaired with a carbon/epoxy composite patch. A fatigue life curve (a = f(N)) was plotted for the patched and unpatched specimens using the results of the experimental tests, and scanning electron microscopy images of the fracture surfaces of the failed specimens were observed. In the numerical part, the elastic–plastic finite element method was used to evaluate the plasticity induced by the overload on the patched plate and to analyze the adhesive damage after this overload was applied. The obtained results demonstrate that the patch deposition of the overload can lead to an extended fatigue life, and the adhesive damage after the overload is quite significant, but the risk of total failure of the adhesive layer is not high.

Numerical desirability function for adsorption of methylene blue dye by sulfonated pomegranate peel biochar: Modeling, kinetic, isotherm, thermodynamic, and mechanism study

Ali H. Jawad,Ahmed Saud Abdulhameed,M. A. K. M. Hanafiah,Zeid A. AlOthman,Mohammad Rizwan Khan,S. N. Surip 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.7

Sulfonated pomegranate (Punica granatum) peel biochar (SPPBC) was developed via thermal activation with sulfuric acid (H2SO4) to act as a promising biochar material for the adsorptive removal of toxic cationic dye namely methylene blue (MB) dye from contaminated water. A Box-Behnken design (BBD) and numerical desirability function were adopted to optimize the input adsorption variables (SPPBC dosage, temperature, pH, and contact time). The maximum removal of the MB dye can be accomplished by simultaneous significant interaction between SPPBC dosage with solution pH, SPPBC dosage with time, SPPBC dosage with temperature, solution pH with time, and time with temperature. The numerical desirability function identified the highest MB dye removal (93.9%) can be achieved at the following optimum numerical adsorption conditions: SPPBC dosage 0.18 g, temperature 49 oC, pH 9.7, and time 4.3 h. Equilibrium data were well fitted to the Temkin and Langmuir isotherm models. The maximum recorded adsorption capacity of SPPBC for MB dye adsorption by using Langmuir isotherm model was 161.9mg/g. This research work reveals the possibility of converting lignocellulose pomegranate peel into a renewable and environmentfriendly biochar via a relatively fast acid-activation process with the great potential to be promising adsorbent for removal of MB dye.

New constituents triterpene ester and sugar derivatives from Panax ginseng Meyer and their evaluation of antioxidant activities

Chung, I.M.,Siddiqui, N.A.,Kim, S.H.,Nagella, P.,Khan, A.A.,Ali, M.,Ahmad, A. Saudi Pharmaceutical Society 2017 Saudi pharmaceutical journal Vol.25 No.5

Panax ginseng C. A. Meyer (Araliaceae), is a well-known herb and used in the old established system of Oriental remedy, especially in Japan, China and Korea. Four new compounds characterized as (cis)- 7β,11α,19,21-tetra-O-decanoyl-18, 22β-dihydroxy-dammar-1-en-3-one (1), 3β,4α,12β-trihydroxystigmast-5-en-21-yl octadecan-9',12'-dienoate (2), dammar-12, 24-dien-3α, 6β, 15α-triol-3α-D-arabinopyranosyl-6β-L-arabinopyranoside (3) and dammar-24-en-3α, 6β, 16α, 20β-tetraol-3α-D-arabinopyranosyl-6β-D-arabinopyranoside (4) were isolated and established from the ethyl acetate and butanol extracts of the roots of P. ginseng. Their structures were established on the basis of spectral data and chemical reactions. Natural compounds indicative a great reservoir of materials and compounds with evolved biological activity, including antioxidant. Compounds 1-4 were investigated in vitro for antioxidant potential using ferric reducing antioxidant power (FRAP), the Nitric oxide (NO) scavenging activity, reducing power, phosphomolybdenum and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging actions, and the decision showed the compounds 3and 4 have probablyessential antioxidant properties than the compounds 1and 2 presented weak activity.

CFD simulation of fluidized bed reactors for polyolefin production – A review

M.J.H. Khan,M.A. Hussain,Z. Mansourpour,N. Mostoufi,N.M. Ghasem,E.C. Abdullah 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

This literature survey focuses on the application of computational fluid dynamics (CFD) in variousaspects of the fluidized bed reactor. Although fluidized bed reactors are used in various industrialapplications, this first-of-its-kind review highlights the use of CFD on polyolefin production. It is shownthat CFD has been utilized for the following mechanisms of polymerization: governing of bubbleformation, electrostatic charge effect, gas–solid flow behavior, particle distribution, solid–gas circulationpattern, bed expansion consequence, mixing and segregation, agglomeration and shear forces. Heat andmass transfer in the reactor modeling using CFD principles has also been taken under consideration. Anumber of softwares are available to interpret the data of the CFD simulation but only few softwarespossess the analytical capability to interpret the complex flowbehavior of fluidization. In this review, thepopular softwares with their framework and application have been discussed. The advantages andfeasibility of applying CFD to olefin polymerization in fluidized beds were deliberated and the prospectof future CFD applications was also discussed.

Reliability analysis of latticed steel towers against wind induced displacement

M.A. Khan,N.A. Siddiqui,H. Abbas 국제구조공학회 2004 Steel and Composite Structures, An International J Vol.4 No.1

The present study aims at the reliability analysis of steel towers against the limit state of deflection. For this purpose tip deflection of the tower has been obtained after carrying out the dynamic analysis of the tower using modal method. This tip deflection is employed for subsequent reliability analysis. A limit state function based on serviceability criterion of deflection is derived in terms of random variables. A complete procedure of reliability computation is then presented. To study the influence of various random variables on tower reliability, sensitivity analysis has been carried out. Design points, important for probabilistic design of towers, are also located on the failure surface. Some parametric studies have also been included to obtain the results of academic and field interest.

A simplified procedure to incorporate soil non-linearity in missile penetration problems

Siddiqui, N.A.,Kumar, S.,Khan, M.A.,Abbas, H. Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.23 No.3

In this paper, a simplified mathematical procedure is presented to incorporate nonlinearity in soil material to predict the deceleration time history, penetration depth and other relevant parameters for normal impact of missiles into soil targets. Numerical method is employed for these predictions. The results of the study are compared with experimental observations and predictions available in the literature. A good agreement is found with experimental observations and an improvement is observed with existing predictions. A comparison is also made with linear soil model. Some parametric studies are also carried out to obtain the results of practical interest.

Experimental Pathogenesis of Pullorum Disease with the Local Isolate of Salmonella enterica serovar. enterica subspecies Pullorum in Pullets in Bangladesh

M. G. Haider,E. H. Chowdhury,M. A. H. N. A. Khan,M. T. Hossain,M. S. Rahman,송희종,M. M. Hossain 한국가금학회 2008 韓國家禽學會誌 Vol.35 No.4

The research work was carried out to study the pathogenesis covering the clinical signs, gross and histopathological lesions in different organs, and reisolation and identification of the organisms after experimental infection with the local isolate of Salmonella enterica serovar. enterica subspecies (S.) Pullorum at different time interval of the experiment during the period February 2006 to December 2006. One hundred pullets (seronegative to S. Pullorum of 12 weeks age were purchased and divided into 5 (A, B, C, D and E) groups and each group consisted of 20 birds. Four groups (A, B, C and D) were infected orally with a dose of 106 CFU, 107 CFU, 2 × 107 CFU, 108 CFU of S. Pullorum, respectively, and one group (E) was treated as uninfected control. The used methods were necropsy and histopathology, culture of bacteria, staining and biochemical test of Salmonella. Five birds from each group were randomly selected and sacrificed 1st week, 2nd, 3rd and 4th weeks of post infection (PI). From all the groups, the bacteriological samples (crop, liver, lung, heart, spleen, bile duodenum, ceca and blood) were collected with pre enriched in buffered peptone water in sterile poly bags. Liver, lungs, heart, spleen, intestine, etc. were collected in 10% buffered-formalin for histopathological examination. No clinical signs, gross and histopathological lesions were found in control group and no S. Pullorum was reisolated. Clinical sign of experimentally infected with S. Pullorum in pullets were loss of appetite (100%), slight depression (75%), ruffled feathers (85%), diarrhea (60%) and loss of weight (100%) in chickens. The feed intake and body weight at different weeks after PI differed significantly (p<0.01) among the groups. Grossly, the highest recorded lesion was button-like ulcer in the ceca (80%) and the lowest was white nodules in lungs (1.25%). S. Pullorum were reisolated from crop (91.25%), liver (91.25%), lung (83.75%), heart (71.25%), spleen (87.75%), bile (33.25%), duodenum (92.50%), ceca (97.50%) and from different group of infection (61.25%). The highest microscopic findings were intestinal and cecal mucosa and submucosa exhibited infiltration of mononuclear cells and congestion (96.25%), and the lowest finding was nodule formation in the lungs (3.75%). The pattern of the disease production by local isolate of S. Pullorum in Bangladesh is almost similar with other isolates in different countries. The research work was carried out to study the pathogenesis covering the clinical signs, gross and histopathological lesions in different organs, and reisolation and identification of the organisms after experimental infection with the local isolate of Salmonella enterica serovar. enterica subspecies (S.) Pullorum at different time interval of the experiment during the period February 2006 to December 2006. One hundred pullets (seronegative to S. Pullorum of 12 weeks age were purchased and divided into 5 (A, B, C, D and E) groups and each group consisted of 20 birds. Four groups (A, B, C and D) were infected orally with a dose of 106 CFU, 107 CFU, 2 × 107 CFU, 108 CFU of S. Pullorum, respectively, and one group (E) was treated as uninfected control. The used methods were necropsy and histopathology, culture of bacteria, staining and biochemical test of Salmonella. Five birds from each group were randomly selected and sacrificed 1st week, 2nd, 3rd and 4th weeks of post infection (PI). From all the groups, the bacteriological samples (crop, liver, lung, heart, spleen, bile duodenum, ceca and blood) were collected with pre enriched in buffered peptone water in sterile poly bags. Liver, lungs, heart, spleen, intestine, etc. were collected in 10% buffered-formalin for histopathological examination. No clinical signs, gross and histopathological lesions were found in control group and no S. Pullorum was reisolated. Clinical sign of experimentally infected with S. Pullorum in pullets were loss of appetite (100%), slight depression (75%), ruffled feathers (85%), diarrhea (60%) and loss of weight (100%) in chickens. The feed intake and body weight at different weeks after PI differed significantly (p<0.01) among the groups. Grossly, the highest recorded lesion was button-like ulcer in the ceca (80%) and the lowest was white nodules in lungs (1.25%). S. Pullorum were reisolated from crop (91.25%), liver (91.25%), lung (83.75%), heart (71.25%), spleen (87.75%), bile (33.25%), duodenum (92.50%), ceca (97.50%) and from different group of infection (61.25%). The highest microscopic findings were intestinal and cecal mucosa and submucosa exhibited infiltration of mononuclear cells and congestion (96.25%), and the lowest finding was nodule formation in the lungs (3.75%). The pattern of the disease production by local isolate of S. Pullorum in Bangladesh is almost similar with other isolates in different countries.

Experimental Pathogenesis of Pullorum Disease with the Local Isolate of Salmonella enterica serovar. enterica subspecies Pullorum in Pullets in Bangladesh

M. G. Haider,E. H. Chowdhury,M. A. H. N. A. Khan,M. T. Hossain,M. S. Rahman,H. J. Song,M. M. Hossain 한국가금학회 2009 韓國家禽學會誌 Vol.35 No.4

Lithium ameliorates lipopolysaccharide-induced neurotoxicity in the cortex and hippocampus of the adult rat brain

Khan, M.S.,Ali, T.,Abid, M.N.,Jo, M.H.,Khan, A.,Kim, M.W.,Yoon, G.H.,Cheon, E.W.,Rehman, S.U.,Kim, M.O. Pergamon Press 2017 Neurochemistry International Vol.108 No.-

Lithium an effective mood stabilizer, primary used in the treatment of bipolar disorders, has been reported as a protective agent in various neurological disorders. In this study, we examined the neuroprotective role of lithium chloride (LiCl) against lipopolysaccharide (LPS) in the cortex and hippocampus of the adult rat brain. We determined that LiCl -attenuated LPS-induced activated toll-like receptor 4 (TLR4) signalling and significantly reduced the nuclear factor-<SUB>k</SUB>B (NF-<SUB>K</SUB>B) translation factor and various other inflammatory mediators such as interleukin-1 beta (IL-1β) and tumour necrosis factor alpha (TNF-α). We also analyzed that LiCl significantly abrogated activated gliosis via attenuation of specific markers for activated microglia, ionized calcium-binding adaptor molecule (Iba-1) and astrocytes, glial fibrillary acidic protein (GFAP) in both the cortex and hippocampus of the adult rat brain. Furthermore, we also observed that LiCl treatment significantly ameliorated the increase expression level of apoptotic neurodegeneration protein markers Bax/Bcl2, activated caspase-3 and poly (ADP-ribose) polymerase-1 (PARP-1) in the cortex and hippocampus regions of the LPS-treated adult rat brain. In addition, the morphological results of the fluoro-jade B (FJB) and Nissl staining showed that LiCl attenuated the neuronal degeneration in the cortex and hippocampus regions of the LPS-treated adult rat brain. Taken together, our Western blot and morphological results indicated that LiCl significantly prevents the LPS-induced neurotoxicity via attenuation of neuroinflammation and apoptotic neurodegeneration in the cortex and hippocampus of the adult rat brain.

Interaction of Glucagon G-Protein Coupled Receptor with Known Natural Antidiabetic Compounds: Multiscoring <i>In Silico</i> Approach

Baig, M. H.,Ahmad, K.,Hasan, Q.,Khan, M. K. A.,Rao, N. S.,Kamal, M. A.,Choi, I. Hindawi Publishing Corporation 2015 Evidence-based Complementary and Alternative Medic Vol.2015 No.-

<P>Glucagon receptor (GCGR) is a secretin-like (class B) family of G-protein coupled receptors (GPCRs) in humans that plays an important role in elevating the glucose concentration in blood and has thus become one of the promising therapeutic targets for treatment of type 2 diabetes mellitus. GCGR based inhibitors for the treatment of type 2 diabetes are either glucagon neutralizers or small molecular antagonists. Management of diabetes without any side effects is still a challenge to the medical system, and the search for a new and effective natural GCGR antagonist is an important area for the treatment of type 2 diabetes. In the present study, a number of natural compounds containing antidiabetic properties were selected from the literature and their binding potential against GCGR was determined using molecular docking and other<I> in silico</I> approaches. Among all selected natural compounds, curcumin was found to be the most effective compound against GCGR followed by amorfrutin 1 and 4-hydroxyderricin. These compounds were rescored to confirm the accuracy of binding using another scoring function (<I>x</I>-score). The final conclusions were drawn based on the results obtained from the GOLD and <I>x</I>-score. Further experiments were conducted to identify the atomic level interactions of selected compounds with GCGR.</P>