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171.
Yuhao Lu Divakar Mantha Ramana G. Reddy 《Metallurgical and Materials Transactions B》2010,41(6):1321-1327
Although many experiments have been performed to reduce the lunar soil by hydrogen, no systematic thermodynamic analysis has
been developed to design and optimize these experiments. Applying a thermodynamic model to the system of simulant lunar soil
and hydrogen, this study analyzes and discusses the thermodynamic behavior of the system in detail. The calculations demonstrate
that iron is the only metal that can be extracted significantly from the lunar soil. The amount of hydrogen in the system
drastically affects the processes of iron extraction and water production. However, the effect of system pressure can be neglected
in the process. The yields of metallic iron and water from the lunar soil as functions of temperature and hydrogen content
are investigated in this study. Additionally, the calculations explain the metallic iron on the surface of the moon from the
thermodynamic point of view. 相似文献
172.
Effects of dietary arachidonic acid on human immune response 总被引:3,自引:0,他引:3
Darshan S. Kelley Peter C. Taylor Gary J. Nelson Perla C. Schmidt Bruce E. Mackey David Kyle 《Lipids》1997,32(4):449-456
Arachidonic acid (AA) is a precursor of eicosanoids, which influence human health and the in vitro activity of immune cells. We therefore examined the effects of dietary AA on the immune response (IR) of 10 healthy men living
at our metabolic suite for 130 d. All subjects were fed a basal diet containing 27 energy percentage (en%) fat, 57 en% carbohydrate,
and 16 en% protein (AA, 200 mg/d) for the first and last 15 d of the study. Additional AA (1.5 g/d) was incorporated into
the diet of six men from day 16 to 65 while the remaining four subjects continued to eat the basal diet. The diets of the
two groups were crossed-over from day 66 to 115. In vitro indexes of IR were examined using the blood samples drawn on days 15, 58, 65, 108, 115, and 127. The subjects were immunized
with the measles/mumps/rubella vaccine on day 35 and with the influenza vaccine on day 92. Dietary AA did not influence many
indexes of IR (peripheral blood mononuclear cell proliferation in response to phytohemagglutinin, Concanavalin A, pokeweed,
measles/mumps/rubella, and influenza vaccines prior to immunization, and natural killer cell activity). The postimmunization
proliferation in response to influenza vaccine was about fourfold higher in the group receiving high-AA diet compared to the
group receiving low-AA diet (P=0.02). Analysis of variance of the data pooled from both groups showed that the number of circulating granulocytes was significantly
(P=0.03) more when the subjects were fed the high-AA diet than when they were fed the low-AA diet. The small increases in granulocyte
count and the in vitro proliferation in response to influenza vaccine caused by dietary AA may not be of clinical significance. However, the lack
of any adverse effects on IR indicates that supplementation with AA may be done safely when needed for other health reasons. 相似文献
173.
Bhagwat S Singh H Athawale A Hannoyer B Jouen S Lefez B Kundaliya D Pasricha R Kulkarni S Ogale S 《Journal of nanoscience and nanotechnology》2007,7(12):4294-4302
We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammonium sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase. 相似文献
174.
Ramaiah Sivakumar Balaraman Manohar Soundar Divakar 《European Food Research and Technology》2007,226(1-2):255-263
Amyloglucosidase from Rhizopus mold and β-glucosidase from sweet almond, catalysed synthesis of vanillyl-maltoside was optimized using response surface
methodology. A central composite rotatable design involving 32 experiments of five variables at five levels was employed.
Among the variables employed, glucosidases (10–50% w/w of maltose), vanillin (0.5–2.5 mmol), incubation period (24–120 h),
buffer volume 0.4–2.0 ml (0.04–0.2 mM) and pH (4.0–8.0); enzyme, buffer concentration and buffer pH were found to be significant
with both the enzymes. Surface plots generated clearly brought out the maltosylation behaviour of the two glucosidases in
this reaction with both the enzymes exhibiting yields in the range 5–60%. Saddle-shaped surface plots observed with both the
enzymes exhibited total reversal of the maltosylation behaviour at certain critical crossover points like 30% (w/w maltose)
enzyme concentration, buffer pH 6.0 and a buffer concentration of 1.25 ml (0.125 mM), implying that a critical enzyme to buffer
concentration and pH dictate the extent of vanillin maltosylation. Validation experiments conducted at certain random selected
conditions as well as those conducted at optimum conditions obtained from the reduced model showed good correspondence between
predicted and experimental yields. 相似文献
175.
K.N. Venkatachalaiah H. Nagabhushana R.B. Basavaraj G.P. Darshan B. Daruka Prasad S.C. Sharma 《中国稀土学报(英文版)》2018,36(9):954-964
In the present communication,various fluxes blended Y_2 O_3:Eu~(3+)(5 mol%) nanopowders(NPs) were successfully fabricated by solution combustion method.PXRD pattern confirms body-centered cubic structure of the prepared samples.Energy band gap(Eg) of the fabricated products was estimated and is found to be in the range of 3.13-3.32 eV.Photoluminescence(PL) emission spectra exhibit sharp and intense peaks at ~579,592,614,657,704 nm corresponding to ~5 D_0→~7 F_J(J = 0,1,2,3 and 4) transitions of Eu~(3+) ions.Significance of fluxes for enhancing the PL emissions was extensively studied.Photometric studies of the prepared samples are located in pure red region.Optimized NPs were explored as a novel sensing agent for visualization of latent fingerprints(LFPs) on various surfaces including porous,semiporous and non-porous surfaces followed by powder dusting technique.Various experiments including aging,temperature,scratching and aquatic fresh water treatment tests were performed to evaluate applicability of the fabricated NPs.Visualized LFPs exhibit well defined ridge details including most authenticated sweat pores are also revealed with high sensitivity,selectivity,little background hindrance and less toxicity.Aforementioned results evidence that the method and fabricated NPs can be considered to be simple,rapid and economical and provide novel sensing platform for LFPs visualization in prospective forensic applications. 相似文献
176.
Neetu Rathore Asita Kulshreshtha Rajesh Kumar Shukla Darshan Sharma 《International Journal of Applied Ceramic Technology》2022,19(3):1766-1778
Here, sol–gel derived Fe–TiO2 anatase nanoparticles with varying concentrations of Ti(1–x)FexO2 (x = 0%, 1%, 5%, 10%) were prepared. The structural, morphological, and optical properties of prepared samples were studied. X-ray diffraction (XRD) patterns show the formation of pure anatase phase. The mean crystallite size of Fe–TiO2 decreases with increase in the concentration of Fe. Fourier transform infrared spectroscopy (FTIR) spectra confirmed the presence of Ti–O vibrational band for all the samples. In Raman spectrum, peak broadening and red shifting linked with Eg ∼144 cm–1 divulge the Fe substitution at Ti sites into host lattice structure. Photoluminescence (PL) spectra verified nine peaks related to near band-edge emission and various defect states. The UV–vis diffuse reflectance spectra represent redshift and reduction in the bandgap energy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations show that the size of the grains decreases with increase in Fe doping concentration. The study shows that Fe-doped TiO2 anatase phase nanoparticles are suitable for photocatalytic activity and solar cell applications. 相似文献