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61.
Karishma Tiwari Pulak Sarkar Solagna Modak Harwinder Singh Sumit Kumar Pramanik Santanu Karan Amitava Das 《Advanced materials (Deerfield Beach, Fla.)》2020,32(8):1905621
Separation membranes with higher molecular weight cut-offs are needed to separate ions and small molecules from a mixed feed. The molecular sieving phenomenon can be utilized to separate smaller species with well-defined dimensions from a mixture. Here, the formation of freestanding polyimine nanofilms with thicknesses down to ≈14 nm synthesized via self-assembly of pre-synthesized imine oligomers is reported. Nanofilms are fabricated at the water–xylene interface followed by reversible condensation of polymerization according to the Pieranski theory. Polyimine nanofilm composite membranes are made via transferring the freestanding nanofilm onto ultrafiltration supports. High water permeance of 49.5 L m-2 h−1 bar−1 is achieved with a complete rejection of brilliant blue-R (BBR; molecular weight = 825 g mol−1) and no more than 10% rejection of monovalent and divalent salts. However, for a mixed feed of BBR dye and monovalent salt, the salt rejection is increased to ≈18%. Membranes are also capable of separating small dyes (e.g., methyl orange; MO; molecular weight = 327 g mol−1) from a mixed feed of BBR and MO. Considering a thickness of ≈14 nm and its separation efficiency, the present membrane has significance in separation processes. 相似文献
62.
Mani Balamurugan Hui‐Yun Jeong Venkata Surya Kumar Choutipalli Jung Sug Hong Hongmin Seo Natarajan Saravanan Jun Ho Jang Kang‐Gyu Lee Yoon Ho Lee Sang Won Im Venkatesan Subramanian Sun Hee Kim Ki Tae Nam 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(25)
The electrochemical reduction of carbon dioxide (CO2) to hydrocarbons is a challenging task because of the issues in controlling the efficiency and selectivity of the products. Among the various transition metals, copper has attracted attention as it yields more reduced and C2 products even while using mononuclear copper center as catalysts. In addition, it is found that reversible formation of copper nanoparticle acts as the real catalytically active site for the conversion of CO2 to reduced products. Here, it is demonstrated that the dinuclear molecular copper complex immobilized over graphitized mesoporous carbon can act as catalysts for the conversion of CO2 to hydrocarbons (methane and ethylene) up to 60%. Interestingly, high selectivity toward C2 product (40% faradaic efficiency) is achieved by a molecular complex based hybrid material from CO2 in 0.1 m KCl. In addition, the role of local pH, porous structure, and carbon support in limiting the mass transport to achieve the highly reduced products is demonstrated. Although the spectroscopic analysis of the catalysts exhibits molecular nature of the complex after 2 h bulk electrolysis, morphological study reveals that the newly generated copper cluster is the real active site during the catalytic reactions. 相似文献
63.
Deepmala Gupta Arvind Kumar Dwivedi Madhu Tripathi 《Lakes & Reservoirs: Research and Management》2019,24(4):391-393
Knowledge of the length–weight relationships (LWRs) of fish is an important tool to understand fish body form, growth pattern, stock management and their conservation. The present study focused on investigating the length–weight relationships for five catfish species, Pachypterus atherinoides (Bloch, 1794), belonging to family Horabagridae; Batasio batasio (Hamilton, 1822) family Bagridae; Bagarius yarrelli (Sykes, 1839), family Gogangra viridescens (Hamilton, 1822); and Sisor rhabdophorus (Hamilton, 1822) belonging to family Sisoridae. Specimens were collected from the middle stretch of the Ganga River in India from November 2016 to May 2018. A total of 174 specimens of five fish species were collected, and their total lengths were measured to the nearest centimetre and the body weight to the nearest gram. The value of the parameter slope (b) of LWRs of the five species ranged from 2.86 (B. yarrelli) to 3.16 (G. viridescens), with a mean value of 2.99. The results of the present study documented the new maximum total length (TL) for P. atherinoides and S. rhabdophorus. The present study also provides the first reference regarding LWRs for S. rhabdophorus. 相似文献
64.
K.M. Srinivasamurthy Jagadeesha Angadi V S.P. Kubrin Shiddaling Matteppanavar D.A. Sarychev P. Mohan Kumar Haileeyesus Workineh Azale B. Rudraswamy 《Ceramics International》2018,44(8):9194-9203
Ferrites may contain single domain particles which gets converted into super-paramagnetic state near critical size. To explore the existence of these characteristic feature of ferrites, we have performed magnetization(M-H loop) and Mössbauer spectroscopic studies of Ni2+ substitution effect in Co1-xNixFe2O4 (where x?=?0, 0.25, 0.5, 0.75 and 1) nanoparticles were fabricated by solution combustion route using mixture of carbamide and glucose as fuels for the first time. As prepared samples exhibit spinel cubic structure with lattice parameters which decreases linearly with increase in Ni2+ concentration. The M-H loops reveals that saturation magnetization(Ms), coercive field(Hc) remanence magnetization(Mr) and magnetron number(ηB) decreases significantly with increasing Ni2+ substitution. The variation of saturation magnetization has been explained on the basis of Neel's molecular field theory. The coercive field(Hc) is found strongly dependent on the concentration of Ni2+ and decrease of coercivity suggests that the particles have single domain and exhibits superparamagnetic behavior. The Mössbauer spectroscopy shows two ferrimagnetically relaxed Zeeman sextets distribution at room temperature. The dependence of Mössbauer parameters such as isomer shift, quadru pole splitting, line width and hyperfine magnetic field on Ni2+ concentration have been discussed. Hence our results suggest that synthesized materials are potential candidate for power transformer application. 相似文献
65.
The technology to produce compatibilized blends of liquid crystalline polymer and highly amorphous cyclic olefin copolymers through two novel approaches were studied. The first approach was to use silane-functionalized halloysite nanotube as nonspecific compatibilizer and the second method was reactive compatibilization. The study of blends and their resulting microstructure; their thermal, mechanical, and viscoelastic properties were investigated. The kinetic study of blends compatibilized through both routes was performed. 相似文献
66.
Sustainable biocomposites have gained considerable interest as an alternative to conventional composites in recent years due to their cost-effectiveness and environmental friendliness. The aim of this study was to investigate the performance and durability behavior of biocomposites from sustainable biocarbon (BC) as compared to conventional established fillers. The poly(butylene terephthalate) (PBT) and its composites reinforced with BC, talc, and glass fiber (GF) were prepared and the durability performances was investigated. The study showed that BC/PBT biocomposites provided a lighter weight alternative to traditionally used fillers. After undergoes thermo-oxidative aging, the mechanical properties of BC/PBT biocomposite were deteriorated. The GF/PBT showed the most stable in retaining its mechanical properties in comparison to the talc/PBT and BC/PBT. The aging behavior and mechanism of the PBT composites were discussed. This study provides further insight on the durability-related properties progression of biocomposites as compared to traditional used fillers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47722. 相似文献
67.
Morampudi Mahesh Kumar Prasad Munaga V. N. K. Raju U. S. N. 《Multimedia Tools and Applications》2020,79(27-28):19215-19237
Multimedia Tools and Applications - Rapid advancement in technology has led to the use of biometric authentication in every field. In particular, from the past few years, iris recognition systems... 相似文献
68.
Ponnusamy Nandha Kumar Shangavi Subramanian Uthirapathy Vijayalakshmi Sanjeevi Kannan 《Journal of the American Ceramic Society》2020,103(6):3528-3540
Structurally stable β-Ca3(PO4)2/t-ZrO2 composite mixtures with the aid of Dy3+ stabilizer were accomplished at 1500°C. The precursors comprising Ca2+, P5+, Zr4+, and Dy3+ have been varied to obtain five different combinations. The results revealed the fact that complete phase transformation of calcium-deficient apatite to β-Ca3(PO4)2 occurred only at 1300°C, whereas the evidence of t-ZrO2 crystallization is obvious at 900°C. The dual occupancy of Dy3+ at β-Ca3(PO4)2 and t-ZrO2 structures was evident; however, Dy3+ initially prefers to occupy β-Ca3(PO4)2 lattice until its saturation limit and thereafter accommodates at the lattice site of ZrO2. The typical absorption and emission behavior of Dy3+ were noticed in all the systems and, moreover, the surrounding symmetry of Dy3+ domains has been determined from the luminescence study. All the systems ensured paramagnetic response that is generally contributed by the presence of Dy3+. A gradual increment in the phase content of t-ZrO2 in the composite mixtures ensured a significant improvement in the hardness and Young's modulus of the investigated compositions. 相似文献
69.
Sharma Rachit Kumar Sarkar Prabir Singh Harpreet 《Clean Technologies and Environmental Policy》2020,22(6):1269-1284
Clean Technologies and Environmental Policy - Manufacturing organizations are under continuous pressure to implement sustainability in their activities. There is a need to identify the... 相似文献
70.
Chloride doped polyaniline conducting polymer films have been prepared in a protic acid medium (HCl) by potentiodynamic method
in an electrochemical cell and studied by cyclic voltammetry and FTIR techniques. The FTIR spectra confirmed Cl- ion doping in the polymers. The polymerization rate was found to increase with increasing concentration of aniline monomer.
But the films obtained at high monomer concentration were rough having a nonuniform flaky polyaniline distribution. Results
showed that the polymerization rate did not increase beyond a critical HCl concentration. Cyclic voltammetry suggested that,
the oxidation-reduction current increased with an increase in scan rate and that the undoped polyaniline films were not hygroscopic
whereas chloride doped polyaniline films were found to be highly hygroscopic. 相似文献