초내열합금 B1900의 미세조직과 인장특성에 미치는 고온노출의 영향

김인수,최백규,서성문,조창용 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.7

Influence of thermal exposure on microstructural evolution and tensile properties of Ni-base superalloy B1900 has been investigated. Phase transformations during thermal exposure and their effects on tensile behavior of the alloy have been analyzed by microstructural observations. Considerable amount of acicular type M_(6)C carbide precipitated in the interdendritic regions (including γ/γ' eutectic) and in the vicinity of MC carbide as a result of thermal exposure above 871°C. Thermal exposure also assisted precipitation of small discrete M_(23)C_(6) carbide which is hard to be found in the alloy. Thermal exposure deteriorated tensile properties of the alloy. The effect of M_(6)C precipitation on the tensile properties of the alloy is not clear. However, degradation of tensile properties of the alloy is primarily attributed to the coarsening of y' phase during thermal exposure. While the localized deformation bands were observed in the as-cast tensile specimen due to shearing of γ' particle, dislocation network formed at γ/γ'interface in the thermally exposed tensile specimen.

Structural and functional significance of the highly-conserved residues in Mycobacterium tuberculosis acetohydroxyacid synthase

Baig, Irshad Ahmed,Moon, Ji-Young,Kim, Min-Seo,Koo, Bon-Sung,Yoon, Moon-Young Elsevier 2014 Enzyme and microbial technology Vol.58 No.-

<P>Mycobacterium tuberculosis AHAS is a potential target for the development of novel anti-tuberculosis agents. Silico analysis showed that conserved His84 and Gln86 residues lie in the catalytic dimer interface of M. tuberculosis AHAS. Mutational analyses of these invariants led to significant reduction in their activity with reduced affinity toward the substrate. Importantly, mutation of Gln86 to Trp abolished complete activity. Further, molecular dynamics simulation studies suggested that these residues are likely to play a key role in maintaining the Glu85 side chain in the required geometry with N1′ atom of ThDP during catalysis. In addition, substitution of essential Glu85 by Ala, Asp, and Gln led to severe drop in catalytic activity with reduced affinity toward ThDP confirming its catalytic role in M. tuberculosis AHAS.</P>

Development of carboxylated TiO₂ incorporated thin film nanocomposite hollow fiber membranes for flue gas dehydration

Baig, M.I.,Ingole, P.G.,Choi, W.K.,Park, S.R.,Kang, E.C.,Lee, H.K. Elsevier Scientific Pub. Co 2016 Journal of membrane science Vol.514 No.-

In this work, thin film nanocomposite (TFN) membranes for water vapor removal have been fabricated by incorporation of carboxylated TiO<SUB>2</SUB> nanoparticles in the polyamide membrane matrix. Surface of pure TiO<SUB>2</SUB> was modified to introduce functional groups on the TiO<SUB>2</SUB> surface and increase the hydrophilicity of the nanoparticles. Modified nanoparticles were then homogeneously dispersed in the aqueous phase monomer (3, 5-diaminobenzoic acid) and reacted with trimesoyl chloride (TMC) to form a thin film nanocomposite membrane (TFN) on top of the polysulfone hollow fiber membrane (HFM) substrate. The carboxylation of TiO<SUB>2</SUB> was confirmed by FTIR spectra. Intrinsic properties of the TFN were analyzed by ATR-FTIR, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle. Introduction of carboxylated TiO<SUB>2</SUB> caused a more dense and cross-linked polyamide layer due to its high binding affinity with the polyamide layer, which was also confirmed by SEM analysis. Furthermore, the addition of modified nanoparticles also increased the hydrophilicity of the TFN membrane due to excess carboxylic groups. Water vapor permeance and selectivity drastically improved due to the increased water vapor permeation paths provided by the modified nanoparticles. A maximum water vapor permeance and selectivity of 1340 GPU and 486 respectively, were obtained at optimum conditions. In addition, effect of reaction time and monomer concentration have also been studied and correlated.

Water vapor transport properties of interfacially polymerized thin film nanocomposite membranes modified with graphene oxide and GO-TiO₂ nanofillers

Baig, Muhammad Irshad,Ingole, Pravin G.,Jeon, Jae-deok,Hong, Seong Uk,Choi, Won Kil,Lee, Hyung Keun Elsevier 2019 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.373 No.-

<P><B>Abstract</B></P> <P>Graphene oxide (GO) and its composite with TiO<SUB>2</SUB> (GT) were utilized as nano-filler materials to prepare highly permeable and water vapor selective nanocomposite membranes. The nano-fillers were characterized using different analytical tools to determine their physicochemical properties. Nanocomposite membranes were prepared by dispersing the nano-fillers in aqueous phase monomer solution for interfacial polymerization reaction on the inner surface of Polysulfone hollow fiber membrane. Surface morphology and bonding chemistry of the nanocomposite membrane was analyzed using various analytical tools. The two types of nano-fillers were compared for their compatibility with the polyamide matrix, and consequently, the water vapor separation performance of the resulting membrane. Results revealed that both the nano-fillers are firmly attached to the polyamide layer via hydrogen and covalent bonds. GT based membranes have higher surface roughness and better hydrophilicity as compared to GO. In addition, GT membranes have more carboxyl groups and lesser degree of cross-linking due to the interference with interfacial polymerization reaction. This leads to a higher permeance (2820 GPU) and a water vapor/nitrogen selectivity when compared to other TFN membranes reported in literature. The nano-fillers act as active sites for preferential transport of water vapor molecules through the membrane thereby, significantly improving water vapor permeance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> GO and GO-TiO<SUB>2</SUB> nanofillers were incorporated in polyamide nanocomposite membrane. </LI> <LI> Improved water vapor permeance was obtained from GO and GO-TiO<SUB>2</SUB> nanofillers incorporated TFN membranes. </LI> <LI> Highly hydrophilic TFN membranes were obtained for water vapor separation. </LI> <LI> GO-TiO<SUB>2</SUB> shows superior water vapor permeance than GO. </LI> <LI> Functionalized GO could improve water vapor permeation even further. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>GO and GO-TiO<SUB>2</SUB> incorporation in TFN membrane by interfacial polymerization for excellent water vapor separation performance.</P> <P>[DISPLAY OMISSION]</P>

Text writing in the air

Baig, Faisal,Khan, Muhammad Fahad,Beg, Saira 한국정보디스플레이학회 2013 Journal of information display Vol.14 No.4

This paper presents a real-time video-based pointing method that allows the sketching and writing of English text over air in front of a mobile camera. The proposed method has two main tasks. First, it tracks the colored fingertip in the video frames and then applies English optical character reorganization over the plotted images to recognize the written characters. Moreover, the proposed method provides a natural human-system interaction without requiring a keypad, stylus, pen, glove, or any other device for character inputs. For the experiments, an application was developed using OpenCv with the JAVA language. The proposed method was tested on a Samsung Galaxy3 android mobile phone. The proposed algorithm showed an average accuracy rate of 92.083% when tested for different shaped alphabets. Here, more than 3000 different shaped characters were used. The proposed system is a software-based approach and is relevantly very simple, fast, and easy to use. It does not require sensors or any hardware other than a camera and red tape, and is applicable to all disconnected languages. It has one issue, though it is color-sensitive in that the existence of any red-colored object in the background before the start of and during the character writing can lead to false results.

Photoluminescence investigation of trivalent rare earth activated Na₃Pb₂(SO₄)₃Cl phosphors for solid state lighting

Baig, N.,Dhoble, N.S.,Yerpude, A.N.,Singh, V.,Dhoble, S.J. Wissenschaftliche Verlagsgesellschaft m. b. H 2016 Optik Vol.127 No.16

<P>In this paper we report the photoluminescence (PL) characteristics of Dy3+, Sm3+, Eu3+ and Tb3+ doped Na3Pb2(SO4)(3)Cl phosphors prepared by wet chemical method. Prepared phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), color co-ordinates and photoluminescence (PL) properties. The emission spectra of Na3Pb2(SO4)(3)Cl:Dy3+ phosphor show the characteristic emission of Dy3+ ions peaking at 478 nm and 573 nm (lambda ex = 390 nm), owing to transitions of F-4(9/2) -> H-6(15/2) and F-4(9/2) -> (6)H(13/)2 receptively. Under 396 nm excitation the Na3Pb2(SO4)(3)Cl:Eu3+ phosphor shows emission at 594 nm and 616 nm due to D-5(0) -> F-7(1) and D-5(0) -> F-7(2) transitions of Eu3+ ions respectively. When Na3Pb2(SO4)(3)Cl:Tb3+ phosphor was excited by 380 nm, the emission spectrum showed intense green band at 545 nm due to D-5(4) -> F-7(5) transition in Tb3+ ion. The PL emission spectrum of Na3Pb2(SO4)(3)Cl:Sm3+ phosphors by 405 nm excitation gave an emission at 562 nm ((4)G(5/2) -> H-6(5/2)), 598 nm ((4)G(5/2) -> H-6(7/2)) and 643 nm ((4)G(5/2) -> H-6(9/2)). The CIE color coordinates indicated that all the above phosphors were suitable as a white light -emitting phosphor. SEM studies of the phosphors show that grain size of the powders prepared by the wet chemical method is about ten micrometers range. From the obtained results it can be concluded that Dy3+, Sm3+ Eu3+ and Tb3+ doped Na3Pb2(SO4)(3)Cl phosphors are potential candidates for solid state lighting applications in green technology. (C) 2016 Elsevier GmbH. All rights reserved.</P>

Interfering PLD1-PED/PEA15 interaction using self-inhibitory peptides: An <i>in silico</i> study to discover novel therapeutic candidates against type 2 diabetes

Baig, Mohammad Hassan,Kausar, Mohd Adnan,Husain, Fohad Mabood,Shakil, Shazi,Ahmad, Irfan,Yadav, Brijesh S.,Saeed, Mohd Elsevier 2019 Saudi journal of biological sciences Vol.26 No.1

<P><B>Abstract</B></P> <P>Diabetes type 2 (T2D) is a very complex disorder with a large number of cases reported worldwide. There are several reported molecular targets which are being used towards drug design. In spite of extensive research efforts, there is no sure shot treatment available. One of the major reasons for this failure or restricted success in T2D research is the identification of a major/breakthrough therapeutic target responsible for the progression of T2D. It has been well documented that one of the major causes mediating the insulin resistance is the interaction of PLD1 with PED/PEA15. Herein, we have performed <I>in silico</I> experiments to investigate the interaction between PLD1 with PED/PEA15. Furthermore, this study has explored pertinent molecular interactions involving the self-derived peptides. The peptides identified in this study are found to be capable of restricting the interaction of these two proteins. Accordingly, the study suggests that the “self-derived peptides” could be used as promising therapeutic candidate(s) against T2D.</P>

Multi-Spectroscopic Characterization of Human Serum Albumin Binding with Cyclobenzaprine Hydrochloride: Insights from Biophysical and <i>In Silico</i> Approaches

Baig, Mohammad Hassan,Rahman, Safikur,Rabbani, Gulam,Imran, Mohd,Ahmad, Khurshid,Choi, Inho MDPI 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.3

<P>Cyclobenzaprine hydrochloride (CBH) is a well-known muscle relaxant that is widely used to relieve muscle spasms and other pain associated with acute musculoskeletal conditions. In this study, we elucidated the binding characteristics of this muscle relaxant to human serum albumin (HSA). From a pharmaceutical and biochemical viewpoint, insight into the structure, functions, dynamics, and features of HSA-CBH complex holds great importance. The binding of CBH with this major circulatory transport protein was studied using a combination of biophysical approaches such as UV-VIS absorption, fluorescence quenching, and circular dichroism (CD) spectroscopy. Various <I>in silico</I> techniques, molecular docking and molecular dynamics, were also used to gain deeper insight into the binding. A reduction in the fluorescence intensities of HSA-CBH complex with a constant increase in temperature, revealed the static mode of protein fluorescence quenching upon CBH addition, which confirmed the formation of the HSA-CBH ground state complex. The alteration in the UV-VIS and far-UV CD spectrum indicated changes in both secondary and tertiary structures of HSA upon binding of CBH, further proving CBH binding to HSA. The analysis of thermodynamic parameters ∆H° and ∆S° showed that binding of CBH to HSA was dominated by intermolecular hydrophobic forces. The results of the molecular docking and molecular dynamics simulation studies also confirmed the stability of the complex and supported the experimental results.</P>

Synthesis and characterization of thin film nanocomposite membranes incorporated with surface functionalized Silicon nanoparticles for improved water vapor permeation performance

Baig, M.I.,Ingole, P.G.,Choi, W.K.,Jeon, J.d.,Jang, B.,Moon, J.H.,Lee, H.K. Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.308 No.-

The present work demonstrates the fabrication of novel thin film nanocomposite membranes incorporating surface functionalized Silicon nanoparticles (average size 15-20nm) for removal of water vapor from nitrogen gas. Silicon nanoparticles were synthesized using the inductively coupled plasma (ICP) technique. The nanoparticles were dispersed in deionized water to introduce hydroxyl functional groups on the surface. The surface functionalization was confirmed by infrared spectroscopy. The effect of nano-Si concentration on the water vapor permeation properties of the TFN membranes was investigated in detail. The hydroxyl functional groups resulted in significant improvement of surface hydrophilicity and roughness of the nanocomposite membranes which in turn enhanced the water solubilization. The small size of nanoparticles permitted extensive interaction between the nanoparticles and the thin film polyamide layer. Increase in the nano-Si concentration resulted in improvement of water vapor permeance and selectivity till 0.5w/w%, above which the selectivity decreased because of the interference in interfacial polymerization reaction due to the dilution of aqueous phase monomer and high loading of nanoparticles. Water vapor permeance in excess of 2200GPU with vapor/N<SUB>2</SUB> selectivity of 501 was obtained when the nano-Si loading was 0.5w/w%. The introduction of nano-Si in the polyamide membrane improved the stability of the nanocomposite membrane such that it slightly resisted the decrease in water vapor permeance with operating temperature.

Use of Platelet-Rich Plasma in Treating Low Back Pain: A Review of the Current Literature

Baig Mirza Zain,Abdullah Umm E Hani,Muhammad Aun,Aziz Abeer,Syed Maryam Jamil,Darbar Aneela 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.1

Low back pain (LBP) is a common problem encountered by physicians. It is a considerable cause of morbidity and socioeconomic loss and is one of the most expensive musculoskeletal disorders. Conventional treatments include bed rest, analgesics, therapeutic exercises, lumbar or caudal epidural corticosteroids, and surgery. Several new biological therapies are being investigated for use in LBP and one of these is platelet-rich plasma (PRP). In this article, we summarize the current literature published on PRP concerning its composition, classification, and application in LBP. We believe our review will prove useful to clinicians and academics alike, interested in new developing therapies for LBP.