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41.
Bioremediation by alkaline protease (AkP) from edible mushroom Termitomyces clypeatus: optimization approach based on statistical design and characterization for diverse applications 下载免费PDF全文
42.
Alessandro Bedini Valentina Zanolli Sandro Zanardi Ugo Bersellini Enrico Dalcanale Michele Suman 《Food Analytical Methods》2013,6(1):17-27
The food industry has a direct interest into bitter-tasting substances either for the identification of negative off-flavors or for the monitoring of a desired organoleptic quality. A rapid technique, based on Fourier transform-near infrared (FT-NIR) spectroscopy and able to detect taste molecular markers in bakery commodities, was developed, focusing the attention on biscuits category. Xanthines (caffeine, theobromine, and theophylline) and polyphenols (catechins and epicathechins), considered as mainly responsible for the bitter-taste of coffee\cocoa\chocolate based products, were firstly checked using a confirmatory liquid chromatography (LC)-ESI\mass spectrometry (MS)-MS procedure after hot methanol–water extraction. Correspondent data were used for the calibration of the FT-NIR through PLS regression. Values of the standard errors of prediction (lower than 10 %) were comparable to the values of the standard errors of cross-validation. Coefficients of determination indicated a good predictive power in the calibration model (R 2 xanthines?=?0.97, R 2 polyphenols?=?0.96) and a satisfying discriminating power among different contents in the validation models (R 2 xanthines?=?0.96, R 2 polyphenols?=?0.96). A testing phase on the generated model was executed by a comparison of LC-MS and sensory panel data with FT-NIR responses recorded on unknown biscuits: differences between found and predicted levels were generally below 5 % and the best predictability was achievable in chocolate-based biscuits. This methodology is able to work directly on solid products, has the potential to be expanded on other categories of gustative molecular markers (like sugars) and can be conceived as applicable for a routine control of a standardized bitter taste quality in a real industrial production. 相似文献
43.
Conoidal shells are very popular roofing units owing to their aesthetic elegance and stiffness. Many parts of the globe, which were earlier assumed to be seismologically stable, are now being considered as earthquake prone. Hence the necessity to build light structures using composites has become very important. In this paper an eight-noded isoparametric shell element is applied for analyzing the bending behavior of delaminated composite conoidal shells under a uniformly distributed load with different practical boundary conditions. To ensure compatibility of deformation and equilibrium of forces and moments at the delamination crack front, a multipoint constraint algorithm is incorporated, which leads to an unsymmetrical stiffness matrix. This formulation is validated through the solution of benchmark problems. Lamination, curvature, and extent of delamination area are varied to compare the performances of delaminated conoidal shells against those with no damage. The results are carefully observed, and a set of conclusions is presented at the end of the paper. 相似文献
44.
45.
Suman Maiti Chandan Chakraborty Sabyasachi Sengupta 《Simulation Modelling Practice and Theory》2009,17(4):585-596
This paper presents a speed estimation technique for the permanent magnet synchronous motor drive. A Model Reference Adaptive System (MRAS) has been formed using the instantaneous and steady-state reactive powers to estimate the speed. It has been shown that such unique MRAS offers several desirable features. The proposed technique is completely independent of stator resistance and is less parameter sensitive, as the estimation-algorithm is only dependent on q-axis stator inductance. Also, the method requires less computational effort as the simplified expressions are used in the MRAS. The stability of the proposed system is achieved through Popov’s Hyperstability criteria. Extensive simulation results are presented to validate the proposed technique. The system is tested at different speeds including zero speed and a very satisfactory performance has been achieved. 相似文献
46.
Suman Dasgupta Dipak Sengupta 《International journal for numerical methods in engineering》1990,30(3):419-430
A new formulation of an eighteen-degrees-of-freedom higher-order triangular plate bending element using triangular area co-ordinates is presented. The displacement function w is taken as the complete fifth-order polynomial in area co-ordinates. The normal slope along an edge of the triangle is constrained to vary cubically. The twenty-one constants are expressed explicity in terms of eighteen degrees of freedom. The element stiffness matrix is expressed as a product of component matrices for which explicit expressions are developed and presented. No numerical inversion or integration is necessary. The formulation is expected to be useful specially for microcomputers. 相似文献
47.
Suman Roy Choudhury Suhasini Roy Choudhury J. Rangarajan R. Rengaswamy 《Journal of power sources》2005,140(2):274-279
Transient state response analysis of phosphoric acid fuel cell (PAFC) cathode is important to understand various competitive processes like diffusion, reaction and product back diffusion occurring at various layers of the composite cathode. A two-dimensional unsteady state model for simulating PAFC cathode is developed as an extension of the previously developed steady-state model [S. Roy Choudhury, M.B. Deshmukh, R. Rengaswamy, A two-dimensional steady-state model for phosphoric acid fuel cells (PAFC), J. Power sources 112 (2002) 137–152]. The transient model is solved to study the impact of various parameters such as Tafel slope, diffusivity etc on the step response of the fuel cell. The effect of partial pressure variation in bulk gas for large sized PAFC cathode is also analysed. Trend analysis based on the model output is also experimentally verified using a small unit cell setup. The effect of various parameters on the settling time of the cathode, as revealed in this study, suggests possible development of a diagnostic tool employing such transient model. 相似文献
48.
V.P. Sakthivel M. Suman P.D. Sathya 《Energy Sources, Part B: Economics, Planning, and Policy》2020,15(6):351-382
ABSTRACT This paper bestows a new swarm intelligence approach, Squirrel Search Algorithm (SSA) to solve Economic Load Dispatch (ELD) of the thermal unit by addressing the valve point loading effects and multiple fuel options. SSA inspires the foraging behavior of squirrels which is based on dynamic jumping and gliding strategies. The main intention of the ELD problem is to minimize the total generation cost of units while assuring various system constraints. Renovate strategy and selection rules are used in the SSA algorithm to handle the constraints appropriately. The practicability of the proposed algorithm is tested on six different power test systems having different sizes and intricacies. Simulation results ascertain that the proposed SSA approach outperforms the other existing heuristic optimization techniques in terms of solution quality, robustness, and computational efficiency. Consequently, the proposed SSA can be an efficient approach for solving the ELD problems with valve point loading impacts and multi-fuel options. 相似文献
49.
Ugur Malayoglu Kadir C. TekinUfuk Malayoglu Suman Shrestha 《Materials Science and Engineering: A》2011,528(24):7451-7460
A ceramic coating on AA6082 aluminum alloy prepared by plasma electrolytic oxidation (PEO) has been studied and compared against a sulphuric acid hard-anodized coating on the same alloy. Surface morphology and microstructures of the coatings have been examined by scanning electron microscopy. X-ray diffraction is used to determine the phase composition of the coatings. The adhesion strength of the coatings has been evaluated using a scratch test method. The coating's mechanical properties such elastic modulus and hardness data have been generated using a dynamic ultra-microhardness tester. Sliding wear tests with different loading rates are performed on the coatings in order to assess their wear resistance. Test results show that the PEO treated samples exhibit significantly better mechanical properties compared to hard anodized samples. The elastic modulus and hardness of the PEO coating are 2-3 times greater than of the hard anodized coating and subsequently, an improved wear resistance of the PEO coating has been achieved. The mechanical properties of the coatings and their relations to their tribological performance are discussed. 相似文献
50.
Do‐Yeon Kim Suman Sinha‐Ray Jung‐Jae Park Jong‐Gun Lee You‐Hong Cha Sang‐Hoon Bae Jong‐Hyun Ahn Yong Chae Jung Soo Min Kim Alexander L. Yarin Sam S. Yoon 《Advanced functional materials》2014,24(31):4986-4995
The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r‐GO) suspension. The r‐GO flakes are used as received, which are pre‐annealed and pre‐hydrazine‐treated, and do not undergo any post‐treatment. A part of the considerable kinetic energy of the r‐GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting “frozen elastic strains” heal the defects (topological defects, namely Stone‐Wales defect and C2 vacancies) in the r‐GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing. 相似文献