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91.
Crystallization behaviour of amorphous aluminium phosphate (AlPO4) and titania (TiO2) in a mixed system of the two (5:1) has been reviewed in the light of our recent results. The polymorphous aluminium phosphate in such a binary system grows exclusively in a single phase over a temperature range 500–1150°C. The phase is reported to have a tridymite-like structure belonging to orthorhombic system with cell parametersa=9·638±0·0019,b=8·664±0·0017 andc=18·280±0036Å. Titania in the system preferentially retains its anatase phase morphology up to a temperature (950°C) well beyond its normal anatase → rutile transformation temperature showing a phenomenon of stabilization of this phase in such mixture. An interfacial reaction mechanism that can explain the observed phenomenon of mutual phase stabilization has been discussed and implications of this result towards the use of such technique for stabilization of various polymorphous compounds in a single phase has been pointed out. 相似文献
92.
Increasing evidence suggests that deposition of amyloid-beta (A beta) peptide leads to neurodegeneration in Alzheimer's disease. Congo red, a histologic dye that binds to amyloid has previously been shown to diminish the toxic effects of A beta in cell culture. Since Congo red is too highly charged to enter the brain in significant quantities, a lipophilic derivative, Chrysamine-G, was tested for the ability to attenuate A beta[25-35]-induced toxicity in PC12 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chrysamine-G showed a concentration-dependent inhibition of A beta[25-35]-induced toxicity. This protective effect became significant at 0.2 microM, a concentration very close to the Ki for Chrysamine-G binding to synthetic A beta (0.37 microM). A decarboxy derivative of Chrysamine-G, which does not bind to A beta, also did not protect against A beta-induced toxicity. The protective effects of Chrysamine-G may relate to its ability to bind directly to A beta and may involve other post-binding effects as well. 相似文献
93.
William E. Martin Debnath Mookherjee Roger Leigh Warren E. Moeller Larry Singell Lay James Gibson Phillip E. Vincent Kenneth Masters Maurice J. Scarlett Charles Richter Howard Teasley Wesley J. Yordon L. J. Evenden Dennis J. O'Connor Andre Simmons James W. Scott Bertrand Renaud 《The Annals of Regional Science》1972,6(1):160-206
94.
Summary A study is made of a two-dimensional mathematical model of nonlinear wave propagation in a shallow tidal estuary using an unconditionally stable numerical scheme. The alternative direction implicit scheme is used to investigate the simulation of the flow pattern of the estuary, and to examine the effects of the changes in the bed topography either due to dredging or due to construction of spurs and guidewalls in tidal flows. The Coriolis force due to rotation of the earth is taken into account in the present two-dimensional model. It is shown that the Coriolis force is responsible for the existence of the transverse component of the flow field. The proposed theoretical model is applied to investigate the flow structure in the Hooghly estuary. The computed results are then compared with the observed values in the Hooghly estuary. A stability analysis of the alternative direction implicit scheme is also included.
With 4 Figures 相似文献
Zweidimensionale nichtlineare Wellenausbreitung in einer Flachwasserflußmündung bei Gezeiten.
Zusammenfassung Es wird ein zweidimensionales mathematisches Modell für die nichtlineare Wellenausbreitung in einer Flachwasserflußmündung mit Gezeiten erarbeitet, das ein stabiles numerisches Verfahren benutzt. Es wird ein implizites Verfahren (alternative direction) gebraucht, um die topographischen Einflüsse des Flußbettes zu simulieren. Die Corioliskraft als Folge der Erddrehung wird bei diesem zweidimensionalen Modell ebenfalls berücksichtigt. Es wird nachgewiesen, daß die Corioliskraft für die transversale Komponente des Stromfeldes verantwortlich ist. Das vorgeschlagene theoretische Modell wird auf die Flußmündung des Hoogly angewendet. Die berechneten Resultate werden mit beobachteten Werten in der Hoogly-Flußmündung verglichen. Eine Stabilitätsuntersuchung des (alternative direction) impliziten Verfahrens wird ebenfalls durchgeführt.
With 4 Figures 相似文献
95.
P. Jha S.P. KoiryVibha Saxena P. VeerenderAbhay Gusain A.K. ChauhanA.K. Debnath D.K. AswalS.K. Gupta 《Organic Electronics》2013,14(10):2635-2644
We have fabricated flexible field-effect transistors (FETs) using poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)], PCDTBT, as an active channel, poly(methyl methacrylate) (PMMA) as gate dielectric and biaxially oriented polyethyleneterephthalate (BOPET) as supporting substrate. The output and transfer characteristics of the devices were measured as a function of channel length. It has been observed that various OFET parameters viz. on–off ratio (∼105), mobility (μ ∼ 10−4 cm2 V−1 s−1), threshold voltage (Vth ∼ −14 V), switch-on voltage (Vso ∼ −6 V), subthreshold slope (S ∼ 7 V/decade) and trap density (Nit ∼ 1014 cm−2 V−1) are almost independent of the channel length, which suggested a very high uniformity of the PCDTBT active layer. These devices were highly stable under atmospheric conditions (temperature: 20–35 °C and relative humidity: 70–85%), as no change in mobility was observed on a continuous exposure for 70 days. The studies on the effect of strain on mobility revealed that devices are stable up to a compressive or tensile strain of 1.2%. These results indicate that PCDTBT is a very promising active layer for the air stable and flexible FETs. 相似文献
96.
Kumarjyoti Roy Subhas Chandra Debnath Natthaphon Raengthon Pranut Potiyaraj 《Polymer Engineering and Science》2019,59(7):1428-1436
Calcium carbonate nanoparticles were synthesized from eggshell waste using ball mill treatment and characterized by Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and field‐emission scanning electron microscopy (FESEM) analysis. Then, waste eggshell‐derived nano calcium carbonate (WESNCC) was used as filler to reinforce natural rubber (NR) composites with and without the presence of maleated natural rubber (MNR) as compatibilizer. MNR‐compatibilized NR/WESNCC composites showed remarkable enhancement in the torque difference, tensile, and thermal properties as compared to either uncompatibilized NR/WESNCC composites or unfilled NR system. Crosslinking degree measurements indicated excellent interfacial interaction between NR matrix and WESNCC in presence of MNR as compatibilizer. A probable mechanism is suggested to explain the interaction between NR matrix and WESNCC in the presence of MNR. This study provides unique way to develop WESNCC‐based rubber composites for future industrial and engineering application. POLYM. ENG. SCI., 59:1428–1436 2019. © 2019 Society of Plastics Engineers 相似文献
97.
Mahipal Singh Kesawat Bhagwat Singh Kherawat Anupama Singh Prajjal Dey Mandakini Kabi Debanjana Debnath Debanjana Saha Ansuman Khandual Sandeep Rout Manorama Asjad Ali Ramasubba Reddy Palem Ravi Gupta Avinash Ashok Kadam Hyun-Uk Kim Sang-Min Chung Manu Kumar 《International journal of molecular sciences》2021,22(16)
Brassinosteroids (BRs) play crucial roles in various biological processes, including plant developmental processes and response to diverse biotic and abiotic stresses. However, no information is currently available about this gene family in wheat (Triticum aestivum L.). In the present investigation, we identified the BZR gene family in wheat to understand the evolution and their role in diverse developmental processes and under different stress conditions. In this study, we performed the genome-wide analysis of the BZR gene family in the bread wheat and identified 20 TaBZR genes through a homology search and further characterized them to understand their structure, function, and distribution across various tissues. Phylogenetic analyses lead to the classification of TaBZR genes into five different groups or subfamilies, providing evidence of evolutionary relationship with Arabidopsis thaliana, Zea mays, Glycine max, and Oryza sativa. A gene exon/intron structure analysis showed a distinct evolutionary path and predicted the possible gene duplication events. Further, the physical and biochemical properties, conserved motifs, chromosomal, subcellular localization, and cis-acting regulatory elements were also examined using various computational approaches. In addition, an analysis of public RNA-seq data also shows that TaBZR genes may be involved in diverse developmental processes and stress tolerance mechanisms. Moreover, qRT-PCR results also showed similar expression with slight variation. Collectively, these results suggest that TaBZR genes might play an important role in plant developmental processes and various stress conditions. Therefore, this work provides valuable information for further elucidate the precise role of BZR family members in wheat. 相似文献
98.
99.
Zhenjing Duan Changhe Li Wenfeng Ding Yanbin Zhang Min Yang Teng Gao Huajun Cao Xuefeng Xu Dazhong Wang Cong Mao Hao Nan Li Gupta Munish Kumar Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali 《机械工程学报(英文版)》2021,34(1):54-88
Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is pro-cessed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be consid-ered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condi-tion,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted. 相似文献
100.
Kishore Debnath Mohit Sisodia Ashutosh Kumar Inderdeep Singh 《Materials and Manufacturing Processes》2016,31(10):1400-1408
Drilling is an inevitable machining technique that facilitates the assembly of composite parts. Drilling with the traditional tools causes significant damage to the composite parts. The forces that are produced during drilling are mostly accountable for the damage or rejection of the parts. Therefore, the main aim of the present investigation is to reduce the forces and subsequent damage that is induced during drilling operation. Thus, new tool geometry has been conceptualized, designed, developed, and implemented to investigate the drilling behavior of sisal-epoxy and nettle-epoxy laminates. A comparative analysis has been made to compare the performance of the developed tool with the widely used twist drill. The performance has been compared based on the forces and associated drilling-induced damage. It was found that the developed tool geometry gives better results than the traditional twist drill in terms of minimization of forces and damage as well. 相似文献