Current scenario and recent advancement of doped carbon dots: a short review scientocracy update (2013–2022)

Ghosh Trisita,Das Tushar Kanti,Das Poushali,Banerji Pallab,Das Narayan Ch. 한국탄소학회 2022 Carbon Letters Vol.32 No.4

The serendipitous uncovering of carbon dot (CQDs) as budding candidate of carbonaceous nanomaterial has become now one of the hot topics in the research of material science and technology. The unique features of CQDs such as photo-physical properties, excellent biocompatibility, ease of synthesis, good aqueous dispersity, high chemical stability, and accessible functional groups for further modification make them one of the promising competitors in biological, photonic and energy-related applications. Although some review articles on CQDs have been published, they typically cover all areas of CQDs applications, and no particular evaluation on the advancement of doped CQDs (D-CQDs) has been reported so far. In this review, we demonstrated characteristic features of D-CQDs focusing on doping strategies, discussion on recently adopted various synthesis processes, its applications and its qualitative comparison with each other. The recently developed concept on understanding the structure and optical properties of D-CQDs are also briefly described followed by their application on various fields primarily concentrated on bio-imaging and sensing applications. We also speculate its use in a variety of intriguing fields and its perspectives in near future.

Fabrication of Reduced Graphene Oxide/Silver Nanoparticles Decorated Conductive Cotton Fabric for High Performing Electromagnetic Interference Shielding and Antibacterial Application

Sabyasachi Ghosh,Sayan Ganguly,Poushali Das,Tushar Kanti Das,Madhuparna Bose,Nikhil K. Singha,Amit Kumar Das,Narayan Ch. Das 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

Conductive filler loading in the polymer matrix is a common practice to transform insulative polymers toconducting composites. In case of textiles, the highly promising approach has been coined by virtue of fabricating withconductive adhesive homogeneous coating. The present fabrication approach has been developed by two-stage wet mixingtechnique including synthesis of silver nanoparticles decorated graphene sheets (rGO/Ag), followed by the preparation ofconducting coating by non-ionic polymer adhesive. The novelty lies in the choice of conductive material and coating strategyto make lightweight and flexible smart electronic fabric. In order to protect the radiation pollution from the immense use ofelectronic devices and gadgets, the coated textiles can be an excellent replacement of other commercially available polymercoatings. The electromagnetic interference (EMI) shielding effectiveness of the prepared coated textile was 27.36 dB in the Xband (8.2-12.4 GHz). Besides this it is worth mentioning that our developed coated fabric was enough conductive to light upa series of 57 LEDs with high intensity. Last but not the least this work also reconnoitres bactericidal feature against E. coli.

부직포의 굽힘강성에 대한 모델링과 구조해석에 관한 연구

박태영,Tushar K. Ghosh 한국섬유공학회 1999 한국섬유공학회지 Vol.36 No.6

A theoretical prediction of bending rigidity of nonwoven fabrics with different bonding characteristics is presented. To study the bending behavior of nonwoven fabrics, we have modified Freeston & Platt's model assuming both no freedom and complete freedom behavior. By reconfiguring the fiber number in a unit cell ($N_{f}$), unit cell shape, and the contribution factor (K), a new equation for bending rigidity is derived. The closer the bonding point is, the more the fibers between adjacent bonding points are likely to behave with no freedom. This fact is relevant to the contribution factor which is the relative contribution portion to bending rigidity and can be determine from the reconfigured bond area and unit cell. The experimental bending rigidity is more dependent on theoretical bending rigidity of the no freedom region than that of the complete freedom region. In general, the theoretical and experimental values of bending rigidity of the nonwoven fabrics show considerably good agreement.

Lithotomy versus prone position for perianal surgery: a randomized controlled trial

Pankaj Kumar,Tushar S Ghosh,Siddhant Sarthak,Prakash Kumar Sasmal 대한대장항문학회 2022 Annals of Coloproctolgy Vol.38 No.2

Purpose: Studies objectively comparing lithotomy and prone positions regarding surgeon comfort, ergonomics, patient comfort, and position related complications are scarce. Methods: The patients posted for surgery of either fistula in ano, hemorrhoids, or were included in this study. Subjective Mental Effort Questionnaire (SMEQ) and Local Experienced Discomfort (LED) scale were used to score the level of mental and physical stress among the operating surgeon, assistants, and the scrub nurse. Other parameters studied were the exposure of the operative site, patient comfort level, and position-related complications. Results: Thirty patients were operated in each position. Mean±standard deviation of jackknife prone vs. lithotomy surgeon SMEQ score (15.6±10.4 vs. 107.0±11.5, P<0.05) and LED score (1.8±1.5 vs. 6.7±0.5, P<0.05) were found to be statistically significant. Prone vs. lithotomy assistant SMEQ score (29.1±13.1 vs. 100.6±8.7, P<0.05) and LED score (4.6±1.1 vs. 7.4±0.8, P<0.05) were also found to be statistically significant. SMEQ (10.0±0.0 vs. 20.6±2.5, P<0.05) and LED scores (1.1±0.3 vs. 3.3±0.5, P<0.05) of scrub nurses and LED scores (2.5±0.5 vs. 6.3±0.7, P<0.05) of patients were also statistically significant. Exposure of the operative site was significantly better in the prone position (5.0 vs. 2.1, P<0.05). Conclusion: Significantly better SMEQ, LED, and exposure score suggests the superiority of jackknife prone position over the lithotomy in terms of significantly less mental and physical stress to the operating surgeon, assistant, and scrub nurse; better ergonomics, and excellent exposure.

부직포의 인장특성과 꿰뚫림특성에 관한 비교분석

박태영,김주용,Tushar K. Ghosh 한국섬유공학회 2000 한국섬유공학회지 Vol.37 No.2

Although many papers have been published on the mechanical properties of nonwoven fabrics, there is no report on the relationship between tensile and puncture properties. For the further application of lightweight nonwoven products in uses such as protective materials, the complete understanding of this relationship should be needed when they are subjected to puncture force. The objectives of this research are to assess the tensile properties with different tensile test methods and to compare the theoretical puncture force calculated by tensile property and experimental puncture force. In the our work, two test methods were used for the tensile properties: uniaxial and biaxial tests. The tensile strength of MD and CD direction. If the condition of tensile test was similar to puncture test, the test method would be in good agreement for predicting the puncture forces. A good correlation between calculated and experimental puncture forces was obtained in the order of biaxial, wide width strip, cut strip, and grab methods.

Role of Heavy Metal Resistant Ochrobactrum sp. and Bacillus spp. Strains in Bioremediation of a Rice Cultivar and Their PGPR Like Activities

Sanjeev Pandey,Pallab Kumar Ghosh,Sisir Ghosh,Tarun Kumar De,Tushar Kanti Maiti 한국미생물학회 2013 The journal of microbiology Vol.51 No.1

The present study demonstrates the metal toxicity ameliorating and growth promoting abilities of three different bacterial isolates when applied to rice as host plant. The three bacterial strains included a cadmium resistant Ochrobactrum sp., a lead resistant Bacillus sp. and an arsenic resistant Bacillus sp. designated as CdSP9, PbSP6, and AsSP9, respectively. When these isolates were used as inocula applied to metaltreated rice plants of variety Satabdi, the germination percentage, relative root elongation (RRE), amylase and protease activities were increased. The toxic effect of metal was reduced in presence of these bacteria. The overall biomass and root/shoot ratio were also enhanced by bacterial inoculation. Hydroponic studies showed that the superoxide dismutase (SOD) activity and malondialdehyde (MDA) level, which had been increased in the presence of metal stress in rice roots, were lowered by the bacterial inoculation. In addition, all three strains were 1-aminocyclopropane-1-carboxylate (ACC) deaminase and catalase positive, whereas siderophore producing ability was lacking in PbSP6. However, both PbSP6 and AsSP9 were protease positive and could hydrolyse starch. The data indicate that these bacteria have promise for bioremediation as well as for plant growth promotion.

Simulation of the Optimized Thermal Conductivity of a Rigid Polyurethane Foam during Its Foaming Process

Siyu An,Galen J. Suppes,Tushar K. Ghosh 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

Thermal conductivity (λ) of a rigid polyurethane (PU) foam plays a vital role in determining the performance of thermal insulation. To accurately predict this property for a given recipe in a few seconds is the first step towards striking a balance between compressive strength, λ, and more properties of a foam product in industrial applications duringformulation. What experimentally observed from PU closed-cell foams made from PAPI-27 Polymeric Methylene Diphenyl Diisocyanate (PMDI), Voranol 360, and n-pentane were: (1) foam shrinkage and even collapse occurred on both low (typically less than 0.9) and ultra-high (close to 2.0) indexes of isocyanate (IA); (2) to achieve the lowest λ for the best thermal insulation, it was suggested to use the highest IA without any foam shrinkage, the fastest stirring rate under safety, and the least physical blowing agent (PBA) until a sharp turn in the trend of λ; (3) there was a definite link between foam density (ρf), closed cell content (ccc), and λ: (a) a low λ requested a high ρf and ccc (b) a denser foam could be achieved by at least three ways. Increasing the agitation rate had a limit, above which the change in density became insignificant. However, a higher IA and reducing the amount of PBA had always been linear with ρf. (c) ρf was the cornerstone of ccc. In low ρf range, a growth of density gave rise to a distinct improvement of ccc, beyond which ccc reached a plateau for any higher density. The foam thermal conductivity during polymerization was successfully simulated by Matlab with 0.0157 % deviation. λ was initially dominated by the contribution from the resin mixture until the gel reaction time. Then, the dominant was shifted to the contribution by the gas component. The magnitude of thermal radiation was rather low throughout the reaction.

Cascade of Complications Following Carotid Body Tumor Excision

Pawan K Garg,Sarbesh Tiwari,Tushar S Ghosh,Surendra Patel,Ankur Sharma,Pushpinder S Khera 대한신경중재치료의학회 2021 Neurointervention Vol.16 No.3

Carotid body tumor excision can lead to various complications including vascular injury and pseudoaneurysm formation. Here we describe a case of carotid body tumor excision followed by series of complications including pseudoaneurysm formation, failure of primary surgical repair, carotid stump syndrome following parent artery occlusion, and persistent hypotension.

An Insight Into the Physico-Mechanical Signatures of Silylated Graphene Oxide in Poly(ethylene methyl acrylate) Copolymeric Thermoplastic Matrix

Sayan Ganguly,Subhadip Mondal,Poushali Das,Poushali Bhawal,Tushar Kanti Das,Sabyasachi Ghosh,Sanjay Remanan,Narayan Chandra Das 한국고분자학회 2019 Macromolecular Research Vol.27 No.3

Dispersion of graphene as nano-building block in polymer matrix is challenging for developing high strength polymer nanocomposites. Tuning of surface polarity can be an effective pathway to resolve this issue of dispersion. Besides this, the polymer matrix (Ethylene methyl acrylate or EMA) has been chosen here judicially due to its polar-nonpolar alternating copolymeric segments which indirectly facilitated dispersion of nanofillers. Herein, graphene oxide has been lyophilically modified by virtue of surface grafting phenomenon with the help of di-halo substituted silane. The most surprising outcome which has been nurtured is their superior dispersion, improvement in physico-mechanical features, and transparency without affecting the inherent compliance of pristine polymer. The transmission electron microscopic image of silane functionalized graphene oxide (GOF) is showing surface roughness which has immense effect of physisorption and mechanical anchoring of polymer chains over GOF nano-sheets. Such physical interaction has enough impact on mechanical properties which has been discussed here. Moreover, the deterioration of transparency was not so much affected after loading of GOF filler. The filler distribution also has been confirmed in the light of small angle X-ray scattering (SAXS) study. Thermal treatment has been conducted for composites which accounted high thermal stability comparatively to pristine polymer.