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221.
Lattice energy and mechanical stiffness of hydroxyapatite 总被引:1,自引:0,他引:1
The lattice energy of the stoichiometric hydroxyapatite is calculated using three methods: the thermochemical method called
Born-Fajans-Haber cycle (BHFC), the semi-empirical electrostatic method based on the generalized Kapustinskii equation, and the Glasser-Jenkins unit cell volume method. The three values of the lattice energy of the hydroxyapatite derived by the three methods are within 4% difference
to each other (BHFC: 34,191 KJ/mole, generalized Kapustinskii equation: 32,808.9 KJ/mole, unit cell volume: 32,997.4 KJ/mole).
The Voigt and Reuss effective elastic moduli of 19 simple ionic crystals, including those of the hydroxyapaptite, are calculated
and are found to be linearly dependent on their volumetric lattice energy density (LED). 相似文献
222.
Reverse micelles have been used, for the first time, to mimic the conditions suitable for the low-temperature (40 degrees C) synthesis of the high temperature and high pressure orthorhombic phase of calcium carbonate (aragonite) normally crystallizing in the sea as abalone shells and as natural pearls. The aragonite phase undergoes morphological changes under higher temperatures with long Y-junctions (at 40 degrees C) to shorter rod-like structures (at 85 degrees C). Pure calcite is obtained at higher reaction temperature. At a lower temperature (5 degrees C) homogeneous and monodisperse spheres of vaterite is obtained. The spherical particles after longer aging (168 h) aggregate to form nanorods and the self assembly is clearly seen at various stages by electron microscopic images. 相似文献
223.
Ashok Sudarsanam Sharad Malik Masahiro Fujita 《Design Automation for Embedded Systems》1999,4(2-3):187-206
We address the problem of code generation for embedded DSP systems. Such systems devote a limited quantity of silicon to program
memory, so the embedded software must be sufficiently dense. Additionally, this software must be written so as to meet various
high-performance constraints. Unfortunately, current compiler technology is unable to generate dense, high-performance code
for DSPs, due to the fact that it does not provide adequate support for the specialized architectural features of DSPs via
machine-dependent code optimizations. Thus, designers often program the embedded software in assembly, a very time-consuming
task. In order to increase productivity, compilers must be developed that are capable of generating high-quality code for
DSPs. The compilation process must also be made retargetable, so that a variety of DSPs may be efficiently evaluated for potential
use in an embedded system. We present a retargetable compilation methodology that enables high-quality code to be generated
for a wide range of DSPs. Previous work in retargetable DSP compilation has focused on complete automation, and this desire
for automation has limited the number of machine-dependent optimizations that can be supported. In our efforts, we have given
code quality higher priority over complete automation. We demonstrate how by using a library of machine-dependent optimization
routines accessible via a programming interface, it is possible to support a wide range of machine-dependent optimizations,
albeit at some cost to automation. Experimental results demonstrate the effectiveness of our methodology, which has been used
to build good-quality compilers for three fixed-point DSPs.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
224.
225.
Anandrao R. Kulkarni Kumaresh S. Soppimath Tejraj M. Aminabhavi Ashok M. Dave Mahesh H. Mehta 《应用聚合物科学杂志》1999,73(12):2437-2446
Polymeric granules were prepared by matrix encapsulation containing 20, 35 and 50% (w/w) of natural liquid pesticide viz., Azadirachta Indica A. Juss. (neem) seed oil (NSO) per dry weight of urea formaldehyde crosslinked starch (UF-St), guar gum (UF-GG) and UF-(St + GG) matrices. Results of swelling and cumulative release kinetics are presented at 35°C for these matrices. The static dissolution experiments have been carried out at 35°C for seven days. The percentage cumulative release kinetic data have been analyzed using an empirical equation to study the release pattern of NSO through the polymeric membranes employed. Transport follows the Super Case II mechanism as tested by an empirical equation. It is found that the release of the active ingredient depends upon the type of the matrix and its swelling ability. The percentage loading of NSO with different matrices and their density exerted an influence on the release data. The FTIR results indicated the absence of chemical interactions between the matrices and the NSO. In the majority of cases, entrapment efficiency was generally more than 95% indicating the efficient encapsulation. Furthermore, the experimental results are discussed in terms of the nature and the combined effect of the individual matrices as well as the percentage loading of NSO. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2437–2446, 1999 相似文献
226.
Geon Joon Lee Pradeep Lamichhane Seong Jae Ahn Seong Hwan Kim Manesh Ashok Yewale Choe Earn Choong Min Jang Eun Ha Choi 《International journal of molecular sciences》2021,22(23)
This research investigated the capture of nitrate by magnesium ions in plasma-activated water (PAW) and its antifungal effect on the cell viability of the newly emerged mushroom pathogen Cryptococcus pseudolongus. Optical emission spectra of the plasma jet exhibited several emission bands attributable to plasma-generated reactive oxygen and nitrogen species. The plasma was injected directly into deionized water (DW) with and without an immersed magnesium block. Plasma treatment of DW produced acidic PAW. However, plasma-activated magnesium water (PA-Mg-W) tended to be neutralized due to the reduction in plasma-generated hydrogen ions by electrons released from the zero-valent magnesium. Optical absorption and Raman spectra confirmed that nitrate ions were the dominant reactive species in the PAW and PA-Mg-W. Nitrate had a concentration-dependent antifungal effect on the tested fungal cells. We observed that the free nitrate content could be controlled to be lower in the PA-Mg-W than in the PAW due to the formation of nitrate salts by the magnesium ions. Although both the PAW and PA-Mg-W had antifungal effects on C. pseudolongus, their effectiveness differed, with cell viability higher in the PA-Mg-W than in the PAW. This study demonstrates that the antifungal effect of PAW could be manipulated using nitrate capture. The wide use of plasma therapy for problematic fungus control is challenging because fungi have rigid cell wall structures in different fungal groups. 相似文献
227.
Bansi L Raina Shri G Agarwal Ashok K Bhatia Govind S Gaur 《Journal of the science of food and agriculture》1996,71(1):27-32
Significant variations were observed in the concentration of pigments (10·0–17·0%, moisture-free basis) and flavour components during different post-harvest processing conditions of saffron (stigmas ex Crocus sativus L). The crocin pigments concentration was highest (15–17%) in the saffron samples dried between 35°C and 50°C either in a solar dryer or in an oven dryer and this also resulted in considerable reduction of normal drying time. Under these conditions the main flavouring component, safranal, was at its peak value of 60% in the oil in almost all the samples except the vacuum oven dried samples which interestingly contained 4-β-hydroxysafranal in major amounts. Studies indicated that 4-β-hydroxysafranal may be an intermediate in the formation of safranal. It was observed that prolonged storage affected the pigments and flavour concentration to a great extent, but proper packaging and storage with 5% moisture in the saffron reduced the deterioration, thereby increasing the shelflife of the product. 相似文献
228.
Nucleotide breakdown products of seer fish (Scomberomorus commerson) steaks stored in O2 scavenger packs during chilled storage 总被引:1,自引:0,他引:1
C.O. Mohan C.N. Ravishankar T.K. Srinivasa Gopal K. Ashok Kumar 《Innovative Food Science and Emerging Technologies》2009,10(2):272-278
Freshness of seer fish (Scomberomorus commerson) steaks packed with and without O2 scavenger was assessed by sensory and chemical methods. O2 scavenger used in the present study reduced the O2 level in the pack to less than 0.01% within 24 h. Samples in air packs were sensorily acceptable only up to 12 days compared to 20 days in O2 scavenger packs. TVB-N levels were 37 and 34 mg N2/100 g and TMA-N levels were 16.4 and 15.2 mg N2/100 g on the day of sensory rejection for air and O2 scavenger packs, respectively. IMP decrease and Hx increase was significantly (P < 0.05) faster in air packed samples compared to O2 scavenger packs. On sensory rejection day, the average K, Ki, P and H values were 63–65%, Fr value was 34% and G value was 178% for O2 scavenger packed samples compared to 81%, 18% and 443% for air packed samples, respectively.Industrial relevanceThe O2 scavenger is an innovative active packaging technique, which is highly effective in reducing the O2 present inside the pack. This can be used in place of traditional vacuum packaging for extending the shelf life of fish products, which reduces the use of vacuum packaging equipments thereby making the process cost effective. 相似文献
229.
Santosh Haunshi Rantu Basumatary P.S. Girish Sunil Doley R.K. Bardoloi Ashok Kumar 《Meat science》2009
In the present study, PCR based method for meat species identification of chicken, duck, pigeon and pig was achieved by developing species-specific markers. Using mitochondrial sequences species-specific primers were designed and the sizes of them were 256 bp, 292 bp, 401 bp and 835 bp for chicken, duck, pigeon and pig, respectively. The species-specific PCR products were sequenced to confirm the specificity of the product amplified. These markers were subsequently tested for cross amplification by checking them with beef, mutton, chevon, pork, rabbit, chicken, duck, turkey and pigeon meat. DNA markers developed in this study can help identify the species of fresh, cooked and autoclaved meat of chicken, duck and pigeon and fresh and cooked meat of pig. The process of identification is simple, economical and quick as compared to other methods such as RAPD, PCR-RFLP and sequencing method of species identification. 相似文献
230.
A simple, sensitive, and highly selective method is proposed for the determination of zinc(II) using a bis-azo dye, 2,6-bis(1-hydroxy-2-naphthylazo)pyridine
as spectrophotometric reagent. At pH 7.8, in 50% (v/v) ethanol–water medium, the complex is found to obey Beer’s law up to 1.3 mg/L with an optimum concentration range between
0.19 and 1.0 mg/L. Sandell’s sensitivity of the color reaction was calculated to be 0.0011 μg cm−2 with molar absorptivity of 6.0 × 104 L mol−1 cm−1 at 560 nm. The optimum conditions for the determination of Zn(II) with the reagent were ascertained. The complexation at
different pH was studied in water–ethanol medium. The composition of the complex is 1:2. The action of some interfering ions
was verified, and the developed method applied successfully for the estimation of zinc levels in food and milk samples, and
the results were then compared with those obtained by using AAS. 相似文献