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排序方式: 共有482条查询结果,搜索用时 15 毫秒
441.
442.
Transparent glasses of CaBi2B2O7 (CBBO) were fabricated via the conventional melt-quenching technique. The amorphous and the glassy nature of the as-quenched
samples were, respectively, confirmed by X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). The glass
transition (T
g) and the crystallization parameters (crystallization activation energy (E
cr) and Avrami exponent (n)) were evaluated under non-isothermal conditions using DSC. The heating rate dependent glass transition and the crystallization
temperatures were rationalized by Lasocka equation for the as-quenched CBBO glasses. There was a close agreement between the
activation energies for the crystallization process determined by Augis and Bennet and Kissinger methods. The variation of
local activation energy (E
c(x)) that was determined by Ozawa method increased with the fraction of crystallization (x). The Avrami exponent (n(x)) decreased with the increase in fraction of crystallization (x), suggesting that there was a changeover in the crystallization process from the bulk to the surface. 相似文献
443.
The ability of iodine to bind amylose has been used to understand a variety of structural and functional aspects of starch in food systems. In this study, the changes in starch granule swelling, polymer leaching and their relationship to pasting properties was investigated by adding iodine to the starch slurry at either room temperature or 95°C. The objective of the study was to investigate the contribution of leached and solubilized starch polymers on the pasting behavior of wheat starch. The addition of very small amounts of iodine (0.1%, dry basis, db) at room temperature increased peak and final pasting viscosities as compared to when no iodine was added. Further increases in iodine concentration resulted in a decrease in peak and final pasting viscosities. The amount of iodine required to completely inhibit granule swelling was more than that required to minimize amylose leaching from the granule. Adding increasing amounts of iodine at 95°C to the starch slurry resulted in the gradual decrease in peak and final pasting viscosities. The contrasting effects of iodine on paste viscosity behavior when added at room temperature or at 95°C suggest that the contribution of extra‐granular amylose on the setback viscosity is minimal and a larger proportion of amylose is retained in the intragranular spaces. 相似文献
444.
Shubhrangshu Mallick Koushik Banerjee Silviu Velicu Christoph Grein Siddhartha Ghosh Jun Zhao 《Journal of Electronic Materials》2008,37(9):1488-1496
Hg1−x
Cd
x
Te mid-wavelength infrared (MWIR) p
+-n
−-n
+ and p
+-n
− avalanche photodiodes (APDs) with a cut-off of 4.9 μm at 80 K were fabricated on Si substrates. Diode characteristics, avalanche characteristics, and excess noise characteristics
were measured on two devices. Temperature-dependent diode and avalanche characterization was performed. Maximum 3 × 106 Ω cm2 and 9 × 105 Ω cm2 zero-bias resistance times active area (R
0
A) products were measured for the p
+-n
−-n and p
+-n devices at 77 K, respectively. Multiplication gains of 1250 and 410 were measured at −10 and −4 V for the p
+-n
−-n
+ and p
+-n APDs at 77 K, respectively, in the front-illumination mode with the help of a laser with an incident wavelength of 632 nm.
The gains reduce to 200 and 50 at 120 K, respectively. The excess noise factor in all APDs was measured to be in the range
of 1 to 1.2. 相似文献
445.
The present paper describes the observations on the treatment of arsenic contaminated synthetic industrial effluent in a bio-column reactor. Ralstonia eutropha MTCC 2487 has been immobilized on the granular activated carbon (GAC) bed in the column reactor. The synthetic water sample containing As(T) (As(III):As(V)=1:1), Fe, Mn, Cu and Zn at the initial concentrations of 25, 10, 2, 5, 10 ppm, respectively, was used. Concentrations of all the elements have been found to be reduced below their permissible limits in the treated water. The significant effect of empty bed contact time (EBCT) and bed height on the arsenic removal was observed in the initial stage. However, after some time of operation (approximately 3-4 days) no such effect was observed. Removal of As(III) and As(V) was almost similar after approximately 2 days of operation. However, at the initial stage As(V) removal was slightly more than that of As(III). In absence of washing, after approximately 4-5 days of operation, the bio-column reactor was observed to act as a GAC column reactor based on physico-chemical adsorption. Like arsenic, the percent removals of Fe, Mn, Cu and Zn also attained minimum after approximately 1 day and increased significantly to the optimum value within 3-4 days of operation. Dissolved oxygen (DO) has been found to decrease along with the increasing bed height from the bottom. The pH of the solution in the reactor has increased slightly and oxidation-reduction potential (ORP) has decreased with the time of operation. 相似文献
446.
Santosh K. Gupta Koushik Kar Sandipan Mishra John T. Wen 《Asian journal of control》2018,20(1):386-402
In this work we propose a framework for incorporating occupant feedback towards temperature control of multi‐occupant spaces, and analyze it using singular perturbation theory. Such a system would typically have to accommodate occupants with different temperature preferences, and incorporate that with thermal correlation among multiple zones to obtain optimal control for minimization of occupant discomfort and energy cost. In current practice, an acceptable temperature set point for the occupancy level of the zone is estimated, and the control law is designed to maintain temperature at the corresponding set point irrespective of the changes in occupancy and the preferences of multiple occupants. Proposed algorithm incorporates active occupant feedback to minimize aggregate user discomfort and total energy cost. Occupant binary feedback in the form of hot/cold or thermal comfort preference input is used by the control algorithm. The control algorithm also takes the energy cost into account, trading it off optimally with the aggregate occupant discomfort. For convergence to the optimal, sufficient separation between the occupant feedback frequency and the temperature dynamics of system is necessary; in absence of which, the occupant feedback provided do not correctly reflect the effect of current control input value on occupant discomfort. Under sufficient time scale separation, using singular perturbation theory, we establish the stability condition of the system and show convergence of the proposed solution to the desired temperature that minimizes energy cost plus occupant discomfort. The occupants are only assumed to be rational in that they choose their own comfort range to minimize individual thermal discomfort. Optimization for a multi‐zone building also takes into account the thermal correlation among different zones. Simulation study with parameters based on our test facility, and experimental study conducted in the same building demonstrates performance of the algorithm under different occupancy and ambient conditions. 相似文献
447.
Vineetha K. V. Kumar P. Ashok Sailaja B. V. S. Guha Koushik Sravani K. Girija Rao K. Srinivasa 《Microsystem Technologies》2018,24(8):3371-3379
Microsystem Technologies - Cholera is caused by vibriocholera bacteria which were present in water or food. Diarrhea is caused by E. coli bacteria which were present in water or food. Bio-sensors... 相似文献
448.
Kumar P. Ashok Sravani K. Girija Sailaja B. V. S. Vineetha K. V. Guha Koushik Rao K. Srinivasa 《Microsystem Technologies》2018,24(12):4909-4920
Microsystem Technologies - In this paper the RF-MEMS switch with series–shunt configuration on a single quartz substrate is presented to achieve high isolation than the individual series or... 相似文献
449.
Khan Muhammad Imran Shoukat Rizwan Mukherjee Koushik Dong Huang 《Microsystem Technologies》2018,24(2):1201-1206
Microsystem Technologies - In this paper we outline the influence of transistor model quality and input signal on the estimates of higher order harmonic contents of switching waveforms emitted by... 相似文献
450.
Poulami Majumder Yichuan Zhang Marcos Iglesias Lixin Fan James A. Kelley Caroline Andrews Nimit Patel Jason R. Stagno Byoung Chol Oh Georg J. Furtmüller Christopher C. Lai Yun‐Xing Wang Gerald Brandacher Giorgio Raimondi Joel P. Schneider 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(38)
Combination therapies that target multiple pathways involved in immune rejection of transplants hold promise for patients in need of restorative surgery. Herein, a noninteracting multiphase molecular assembly approach is developed to crystallize tofacitinib, a potent JAK1/3 inhibitor, within a shear‐thinning self‐assembled fibrillar peptide hydrogel network. The resulting microcrystalline tofacitinib hydrogel (MTH) can be syringe‐injected directly to the grafting site during surgery to locally deliver the small molecule. The rate of drug delivered from MTH is largely controlled by the dissolution of the encapsulated microcrystals. A single application of MTH, in combination with systemically delivered CTLA4‐Ig, a co‐stimulation inhibitor, affords significant graft survival in mice receiving heterotopic heart transplants. Locoregional studies indicate that the local delivery of tofacitinib at the graft site enabled by MTH is required for the observed enhanced graft survival. 相似文献