Extraction of hexavalent chromium by environmentally benign green emulsion liquid membrane using tridodecyamine as an extractant

Anil Kumar,Avinash Thakur,Parmjit Singh Panesar 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

In this present investigation, the potentiality of rice bran oil (RBO) and tridodecylamine (TDDA) to be incorporated as the key constituents in the formulation of new environmentally benign green emulsion liquid membrane (GELM) to extract hexavalent chromium (Cr(VI)) from aqueous feed phase was explored. The pertinent constituents of GELM were RBO (70%, v/v) and hexane (30%, v/v) as green and organic diluent, respectively; TDDA (0.75 (%, v/v) of diluent solution) as carrier; emulsifying agent (span 80: 1.75 (%v/v) of diluent solution); and NaOH as internal reagent. The investigation of optimum process conditions for various parameters has resulted in 0.45 pH of aqueous solution, 0.25 [M] internal phase concentration, 2:1 (v/v) treat ratio, 0.40 (v/v) phase ratio, 550 (rpm) agitation speed, 25 (min) extraction time, and 30 ± 2 (°C) feed phase temperature. The highest achievable extraction efficiency (η, %) and dynamic stability (min) of GELM have been obtained as 97 ± 2% and 150 ± 2 min, respectively under these optimum process conditions. The present finding has revealed that RBO as a green diluent has huge capability to be further utilized for the extraction of Cr (VI) from various industrial effluent streams.

Yield enhancement of matrix precursor in short carbon fiber reinforced randomly oriented carbon/carbon composite

Thakur Sudesh Kumar Raunija,Sharad Chandra Sharma,Anil Verma 한국탄소학회 2016 Carbon Letters Vol.19 No.-

Isroaniso matrix precursor synthesized from commercially available petroleum pitch was stabilized in air. The influence of oxygen mass gain during stabilization on the yield of matrix precursor was studied. Additionally, the influence of pressure on the yield of the stabilized matrix precursor in a real system was studied. The fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), yield, yield rate, and yield impact were used to check the effect of stabilization and pressure on the yield of the matrix precursor and the end properties of the composite thereafter. The results showed that the yield increased with stabilization duration up to 20 h whereas it decreased for stabilization duration beyond 20 h. Further results showed that the stabilized matrix precursor for a duration of 5 h could withstand almost two-fold greater hot-pressing pressure without resulting in exudation as compared to that of a 1 h stabilized matrix precursor. The enhanced hot-pressing pressure significantly improved the yield of the matrix precursor. As a consequence, the densification and mechanical properties were increased significantly. Further, the matrix precursor stabilized for a duration of 20 h or more failed to provide proper and uniform binding of the reinforcement.

Quantum Information Entropy and Entropy Squeezing of Isospectral Modified Hylleraas Plus Exponential Rosen Morse Potential and Isospectral Eckart Potential

Pooja Thakur,Rama Gupta,Aarti Sharma,Anil Kumar 한국물리학회 2020 새물리 Vol.70 No.9

We have numerically evaluated the position space and momentum space information entropy of the isospectral Modified Hylleraas plus exponential Rosen Morse potential and established that each level can be re-arranged as a function of the deformation parameter. The information densities of this potential have been graphically demonstrated and their properties thoroughly analyzed. An asymmetric shape dependence on the values of quantum number (n; l) is observed for the position space information densities. The characteristic features of the information entropy in position and momentum space have been analyzed, and the lower bound of the sum of the entropies, expressed by using the Bialynicki-Birula and Mycielski inequality is satisfied. Compared to undeformed potential exhibiting squeezing phenomena in momentum space only the information entropy squeezing has been realized for position space, as well as momentum space, as a function of the deformation parameter with the choice of the same set of parameters. Interestingly, squeezed coherent states are obtained for the isospectral Eckart potential.

Morphological optimization of process parameters of randomly oriented carbon/carbon composite

Raunija, Thakur Sudesh Kumar,Manwatkar, Sushant Krunal,Sharma, Sharad Chandra,Verma, Anil 한국탄소학회 2014 Carbon Letters Vol.15 No.1

A microstructure analysis is carried out to optimize the process parameters of a randomly oriented discrete length hybrid carbon fiberreinforced carbon matrix composite. The com-posite is fabricated by moulding of a slurry into a preform, followed by hot-pressing and carbonization. Heating rates of 0.1, 0.2, 0.3, 0.5, 1, and 3.3ºC/min and pressures of 5, 10, 15, and 20 MPa are applied during hot-pressing. Matrix precursor to reinforcement weight ra-tios of 70:30, 50:50, and 30:70 are also considered. A microstructure analysis of the carbon/carbon compacts is performed for each variant. Higher heating rates give bloated compacts whereas low heating rates give bloating-free, finemicrostructure compacts. The compacts fabricated at higher pressure have displayed side oozing of molten pitch and discrete length carbon fibers.The microstructure of the compacts fabricated at low pressure shows a lack of densification.The compacts with low matrix precursor to reinforcement weight ratios have insufficientbonding agent to bind the reinforcement whereas the higher matrix precursor to reinforcement weight ratio results in a plaster-like structure. Based on the microstructure analysis, a heating rate of 0.2ºC/min, pressure of 15 MPa, and a matrix precursor to rein-forcement ratio of 50:50 are found to be optimum w.r.t attaining bloating-free densificationand processing time.

APE1/Ref-1 as an emerging therapeutic target for various human diseases: phytochemical modulation of its functions

Shweta Thakur,Bibekananda Sarkar,Ravi P Cholia,Nandini Gautam,Monisha Dhiman,Anil K Mantha 생화학분자생물학회 2014 Experimental and molecular medicine Vol.46 No.-

Apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional enzyme involved in the base excision repair (BER) pathway, which repairs oxidative base damage caused by endogenous and exogenous agents. APE1 acts as a reductive activator of many transcription factors (TFs) and has also been named redox effector factor 1, Ref-1. For example, APE1 activates activator protein-1, nuclear factor kappa B, hypoxia-inducible factor 1a, paired box gene 8, signal transducer activator of transcription 3and p53, which are involved in apoptosis, inflammation, angiogenesis and survival pathways. APE1/Ref-1 maintains cellular homeostasis (redox) via the activation of TFs that regulate various physiological processes and that crosstalk with redox balancing agents (for example, thioredoxin, catalase and superoxide dismutase) by controlling levels of reactive oxygen and nitrogen species. The efficiency of APE1/Ref-1’s function(s) depends on pairwise interaction with participant protein(s), the functions regulated by APE1/Ref-1 include the BER pathway, TFs, energy metabolism, cytoskeletal elements and stressdependent responses. Thus, APE1/Ref-1 acts as a ‘hub-protein’ that controls pathways that are important for cell survival. In this review, we will discuss APE1/Ref-1’s versatile nature in various human etiologies, including neurodegeneration, cancer, cardiovascular and other diseases that have been linked with alterations in the expression, subcellular localization and activities of APE/Ref-1. APE1/Ref-1 can be targeted for therapeutic intervention using natural plant products that modulate the expression and functions of APE1/Ref-1. In addition, studies focusing on translational applications based on APE1/Ref-1-mediated therapeutic interventions are discussed.

Intrinsic Vertebral Markers for Spinal Level Localization in Anterior Cervical Spine Surgery: A Preliminary Report

Deepak Kumar Jha,Anil Thakur,Mukul Jain,Arvind Arya,Chandrabhushan Tripathi,Rima Kumari,Suman Kushwaha 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.6

Study Design: Prospective clinical study. Purpose: To observe the usefulness of anterior cervical osteophytes as intrinsic markers for spinal level localization (SLL) during sub-axial cervical spinal surgery via the anterior approach. Overview of Literature: Various landmarks, such as the mandibular angle, hyoid bone, thyroid cartilage, first cricoid ring, and C6 carotid tubercle, are used for gross cervical SLL; however, none are used during cervical spinal surgery via the anterior approach. We present our preliminary assessment of SLL over anterior vertebral surfaces (i.e., intrinsic markers) in 48 consecutive cases of anterior cervical spinal surgeries for the disc-osteophyte complex (DOC) in degenerative diseases and granulation or tumor tissue associated with infectious or neoplastic diseases, respectively, at an ill-equipped center. Methods: This prospective study on patients undergoing anterior cervical surgery for various sub-axial cervical spinal pathologies aimed to evaluate the feasibility and accuracy of SLL via intraoperative palpation of disease-related morphological changes on anterior vertebral surfaces visible on preoperative midline sagittal T1/2-weighted magnetic resonance images. Results: During a 3-year period, 48 patients (38 males,10 females; average age, 43.58 years) who underwent surgery via the anterior approach for various sub-axial cervical spinal pathologies, including degenerative disease (n= 42), tubercular infection (Pott’s disease; n=3), traumatic prolapsed disc (n=2), and a metastatic lesion from thyroid carcinoma (n=1), comprised the study group. Intrinsic marker palpation yielded accurate SLL in 79% of patients (n=38). Among those with degenerative diseases (n=42), intrinsic marker palpation yielded accurate SLL in 76% of patients (n=32). Conclusions: Intrinsic marker palpation is an attractive potential adjunct for SLL during cervical spinal surgeries via the anterior approach in well-selected patients at ill-equipped centers (e.g., those found in developing countries). This technique may prove helpful when radiographic visualization is occasionally inadequate.