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Sample records for simple hydrothermal method

  1. Synthesis and Characterization of Strontium Carbonate Nanostructures via Simple Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Asgari-Fard, Zahra; Sabet, Mohammad; Salavati-Niasari, Masoud

    2016-02-01

    Strontium carbonate (SrCO3) nanostructures were synthesized via simple hydrothermal method by Sr(NO3)2, ethylenediamine and hydrazine as reagents. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR). Different parameter's effects on the product size and morphology were investigated. It was found that reagent concentration, reaction time and temperature play key roles in morphology of the obtained product.

  2. Degradation of Tetracycline with BiFeO3 Prepared by a Simple Hydrothermal Method

    PubMed Central

    Xue, Zhehua; Wang, Ting; Chen, Bingdi; Malkoske, Tyler; Yu, Shuili; Tang, Yulin

    2015-01-01

    BiFeO3 particles (BFO) were prepared by a simple hydrothermal method and characterized. BFO was pure, with a wide particle size distribution, and was visible light responsive. Tetracycline was chosen as the model pollutant in this study. The pH value was an important factor influencing the degradation efficiency. The total organic carbon (TOC) measurement was emphasized as a potential standard to evaluate the visible light photocatalytic degradation efficiency. The photo-Fenton process showed much better degradation efficiency and a wider pH adaptive range than photocatalysis or the Fenton process solely. The optimal residual TOC concentrations of the photocatalysis, Fenton and photo-Fenton processes were 81%, 65% and 21%, while the rate constants of the three processes under the same condition where the best residual TOC was acquired were 9.7 × 10−3, 3.2 × 10−2 and 1.5 × 10−1 min−1, respectively. BFO was demonstrated to have excellent stability and reusability. A comparison among different reported advanced oxidation processes removing tetracycline (TC) was also made. Our findings showed that the photo-Fenton process had good potential for antibiotic-containing waste water treatment. It provides a new method to deal with antibiotic pollution. PMID:28793568

  3. Degradation of Tetracycline with BiFeO₃ Prepared by a Simple Hydrothermal Method.

    PubMed

    Xue, Zhehua; Wang, Ting; Chen, Bingdi; Malkoske, Tyler; Yu, Shuili; Tang, Yulin

    2015-09-18

    BiFeO₃ particles (BFO) were prepared by a simple hydrothermal method and characterized. BFO was pure, with a wide particle size distribution, and was visible light responsive. Tetracycline was chosen as the model pollutant in this study. The pH value was an important factor influencing the degradation efficiency. The total organic carbon (TOC) measurement was emphasized as a potential standard to evaluate the visible light photocatalytic degradation efficiency. The photo-Fenton process showed much better degradation efficiency and a wider pH adaptive range than photocatalysis or the Fenton process solely. The optimal residual TOC concentrations of the photocatalysis, Fenton and photo-Fenton processes were 81%, 65% and 21%, while the rate constants of the three processes under the same condition where the best residual TOC was acquired were 9.7 × 10(-3), 3.2 × 10(-2) and 1.5 × 10(-1) min(-1), respectively. BFO was demonstrated to have excellent stability and reusability. A comparison among different reported advanced oxidation processes removing tetracycline (TC) was also made. Our findings showed that the photo-Fenton process had good potential for antibiotic-containing waste water treatment. It provides a new method to deal with antibiotic pollution.

  4. Study of various Sb{sub 2}S{sub 3} nanostructures synthesized by simple solvothermal and hydrothermal methods

    SciTech Connect

    Senthil, T.S.; Muthukumarasamy, N.; Kang, Misook

    2014-09-15

    Controlling the size and morphology of the antimony sulfide nanostructures is important for photocatalytic and photovoltaic applications. Herein, we report a systematic approach to synthesize various nanostructures of antimony sulfide. Based on simple solvothermal and hydrothermal routes antimony sulfide nanorods have been synthesized at different temperatures. The size of the nanorods and the morphology of the constituent nano-units, in the form of nanorods, dumbbell and sphere have been controlled by adjusting the temperature. The changes have been confirmed by scanning electron microscope and transmission electron microscope analysis. - Highlights: • We prepared dumbbell structured Sb{sub 2}Sb{sub 3} by simple solvothermal and hydrothermal method. • Investigated the importance of bath temperature on the formation of various structures. • Growth mechanism of dumbbell like structured Sb{sub 2}S{sub 3} nanorods was estimated.

  5. Synthesis of pyrite FeS2 nanorods by simple hydrothermal method and its photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Morales-Gallardo, M. V.; Ayala, A. M.; Pal, Mou; Cortes Jacome, M. A.; Toledo Antonio, J. A.; Mathews, N. R.

    2016-09-01

    In this work, FeS2 nanorods were synthetized by hydrothermal method. The advantages of our process were the high yield, simplicity and reproducibility. The material was studied in detail using different experimental tools such as XRD, SEM, HRTEM, EDXS, XPS, Raman, and UV-vis reflectance. XRD pattern and Raman data revealed good crystalline quality for the as synthesized pyrite FeS2. SEM analysis displayed the rod-like morphologies of FeS2 which seemed to grow radially from a center giving a flower-like appearance. From TEM images the approximate length and diameter of nano-rods were determined as 275 and 15 nm respectively. The material showed excellent photocatalytic activity which was assessed from the degradation of the methlyene blue.

  6. Controllable synthesis of CuFe2O4 nanostructures through simple hydrothermal method in the presence of thioglycolic acid

    NASA Astrophysics Data System (ADS)

    Paramasivan, P.; Venkatesh, P.

    2016-10-01

    In this paper a novel and simple route for the preparation of copper ferrite (CuFe2O4) is proposed. The present investigation reports, the novel synthesis of CuFe2O4 samples C1, C2, C3 and C4 using hydrothermal method and its physicochemical characterization. In order to elucidate the relationship between the constituent, structure, magnetic and PL properties product's particle size, morphological and structural properties were characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), photoluminescence (PL) and magnetic properties. The crystallization, surface morphology, magnetic properties and luminescence properties of the samples have been investigated. The relatively high Ms of the samples suggests that this method is suitable for preparing high-quality nanocrystalline copper ferrites for practical applications. Different mechanisms to explain the obtained results and the correlation between magnetism and structure are discussed.

  7. A simple hydrothermal method for the large-scale synthesis of single-crystal potassium tungsten bronze nanowires.

    PubMed

    Gu, Zhanjun; Ma, Ying; Zhai, Tianyou; Gao, Bifen; Yang, Wensheng; Yao, Jiannian

    2006-10-10

    The large-scale synthesis of single-crystal K(x)WO(3) tungsten bronze nanowires has been successfully realized by a hydrothermal method under mild conditions. Uniform K(0.33)WO(3) nanowires with diameters of 5-25 nm and lengths of up to several micrometers are obtained. It is found that the morphology and crystallographic forms of the final products are strongly dependent on the sulfate and citric acid, which may act as structure-directing and soft-reducing agent, respectively. Some other influential factors on the growth of tungsten bronze nanowires, such as temperature and reaction time, are also discussed. It is worth noting that other alkali metal tungsten bronzes such as (NH(4))(x)WO(3), Rb(x)WO(3), and Cs(x)WO(3) could also be selectively synthesized by a similar route. Thus, this novel and efficient method could provide a potential mild route to selectively synthesize various tungsten bronze on-dimensional nanomaterials.

  8. Effect of calcination temperature on structural and photocatalyst properties of nanofibers prepared from low-cost natural ilmenite mineral by simple hydrothermal method

    SciTech Connect

    Simpraditpan, Athapon; Wirunmongkol, Thanakorn; Pavasupree, Sorapong; Pecharapa, Wisanu

    2013-09-01

    Graphical abstract: - Highlights: • Nanofibers were prepared from low-cost ilmenite mineral via simple hydrothermal. • High photocatalyst nanofibers were prepared via post heat treatment method. • The nanofibers calcined at 100–700 °C for 2 h maintained nanofiber structure. • The calcined nanofibers at 400 °C showed the highest photocatalytic activity. - Abstract: Titanate nanofibers were synthesized via the hydrothermal method (120 °C for 72 h) using natural ilmenite mineral (FeTiO{sub 3}) as the starting material. The samples were characterized by X-ray diffraction (XRD), X-ray fluorescent (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET) for specific surface area. The nanofibers were 20–90 nm in diameter and 2–7 μm in length. The as-synthesized nanofibers calcined at 300–400 °C showed TiO{sub 2} (B) whereas the nanofibers calcined at 500 °C revealed a mixture of two phases of TiO{sub 2} (B) and anatase. The nanofibers calcined at high temperature of 600–1000 °C showed a mixture of tri-crystalline of anatase, rutile, and Fe{sub 2}O{sub 3}. The rutile phase increased with increasing calcination temperature. The nanofibers calcined at 300–700 °C maintained their structure while the morphology of the nanofibers calcined at 800–1000 °C transformed into submicron rod-like structure. This increase of calcination temperature led to the phase transformation from thermodynamically metastable anatase to the most stable form of rutile phase. The crystallite size of prepared samples increased with increasing calcination temperature. Interestingly, with increasing calcination temperature, the absorption edge of the prepared samples shows an obvious shift to visible light region due to the change of crystallite phase and increased crystallite size. Therefore, the band gap energy of the prepared samples became narrower with increasing calcination temperature. Furthermore, the

  9. Magnetic properties of cobalt ferrite synthesized by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Allaedini, Ghazaleh; Tasirin, Siti Masrinda; Aminayi, Payam

    2015-05-01

    In this study, the magnetic properties of nanocrystalline cobalt ferrite synthesized via the hydrothermal method have been investigated. The structural properties of the produced powders were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The observed XRD pattern confirmed the spinel/cubic structure of the prepared cobalt ferrite. The SEM pictures show that the simple hydrothermal method produces uniform sphere-shaped nanopowders. Moreover, infrared spectroscopy was used to confirm the formation of cobalt ferrite particles. Magnetic hysteresis was measured using a vibrating sample magnetometer in a maximum field of 10 kOe. The magnetization of the prepared nanoparticles was investigated, and the saturation magnetization ( M s), remanence ( M r), and coercivity ( H c) were derived from the hysteresis loops. The results revealed that the cobalt ferrite nanoparticles synthesized via the simple hydrothermal method exhibit superior magnetic properties.

  10. The preparation of La2O3@AAO with simple hydrothermal method under ambient pressure and the enhanced electrowetting-on-dielectric performance

    NASA Astrophysics Data System (ADS)

    Jin, Hongxia; Wang, Jian; Yin, Yangyang; An, Yuying; Wang, Xiangzhuo; Li, Yan; Wang, Chengwei; Lv, Yudong

    2017-10-01

    Anodic aluminum oxide (AAO) has unique nanostructure and is a conventional EWOD material. The lanthanum oxide, a kind of rare-earth oxide, has unique electronic structure and high dielectric constant, but its synthesis is still complicated. A simple method is proposed to prepare the La2O3@AAO nanocomposites through immersing highly ordered AAO films into La(NO3)3 solution under ambient temperature and pressure and subsequent annealing. It can be known that when the immersion temperature gets to 60 °C, the La2O3 starts to grow in AAO by the characterization of morphology, crystal phase structure and surface chemical composition. The measurement of EWOD performance indicates that the incorporation of La2O3 into AAO greatly enhances the capacitance about 2-3 orders of magnitude, and the large contact angle modulation is acquired. Furthermore, the EW properties of La2O3@AAO nanocomposites, such as relaxation time, critical voltage, can be easily modulated by the immersion temperature and time.

  11. Simple Poroelastic Models for the Tidal Modulation of Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Schultz, A.; Jupp, T.

    2002-12-01

    Time-series measurements of the temperature and velocity of hydothermal effluent suggest that seafloor hydrothermal systems are tidally modulated. Here, we apply the theory of poroelasticity to predict the magnitude and phase of tidally induced temperature and velocity signals at the seafloor relative to each harmonic component of the ocean tide. Firstly, we consider the idealised case of a one-dimensional permeable layer of depth H in which hot effluent ascends with bouyancy-driven volume flux w. Pore pressure variations of a given frequency ω penetrate the crust over a lengthscale D, known as the diffusive skindepth. The subsequent tidal variations in temperature and flow rate are controlled by two dimensionless parameters. The first parameter H/D measures the depth of the permeable layer relative to the skindepth. The second parameter ω D / w measures the timescale of the tidal loading relative to the timescale of the background bouyancy driven flow. We derive analytical solutions in this simplified one-dimensional case as a function of the dimensionless parameters, and discuss discuss their application to real systems. Secondly, we consider how the temperature variations within an idealised (two-dimensional) hydrothermal cell affect its poroelastic paramaters. In hydrothermal systems, the interstitial water is `liquid-like' below ~ 400o {C} and `gas-like' above ~ 400o {C}. This leads to a marked difference in the poroelastic response between the majority of the cell (in which the water is `liquid-like') and the very hot region at the base of the system (in which it is `gas-like').

  12. Synthesis of Nanoparticles via Solvothermal and Hydrothermal Methods

    SciTech Connect

    Li, Jianlin; Wu, Qingliu; Wu, Ji

    2015-01-01

    This chapter summarizes the synthesis of various types of nanoparticles as well as surface modifications of nanomaterials using hydrothermal and solvothermal methods. First, the definition, history, instrumentation, and mechanism of hydrothermal and solvothermal methods as well as the important parameters af-fecting the nucleation and crystal growth of nanomaterials are briefly introduced. Then the specific hydrothermal and solvothermal methods used to grow oxides, Group II-VI, III-V, IV, transitional metals, and metal-organic framework nanoparticles are summarized. Finally, the hydrothermal and solvothermal strategies used for the surface modification of nanomaterials are discussed.

  13. A series of spinel phase cathode materials prepared by a simple hydrothermal process for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Liang, Yan-Yu; Bao, Shu-Juan; Li, Hu-Lin

    2006-07-01

    A series of spinel-structured materials have been prepared by a simple hydrothermal procedure in an aqueous medium. The new synthetic method is time and energy saving i.e., no further thermal treatment and extended grinding. The main experimental process involved the insertion of lithium into electrolytic manganese dioxide with glucose as a mild reductant in an autoclave. Both the hydrothermal temperature and the presence of glucose play the critical roles in determining the final spinel integrity. Particular electrochemical performance has also been systematically explored, and the results show that Al 3+, F - co-substituted spinels have the best combination of initial capacity and capacity retention among all these samples, exhibited the initial capacity of 115 mAh/g and maintained more than 90% of the initial value at the 50th cycle.

  14. Simple hydrothermal synthesis of metal oxides coupled nanocomposites: Structural, optical, magnetic and photocatalytic studies

    NASA Astrophysics Data System (ADS)

    Ganeshraja, Ayyakannu Sundaram; Clara, Antoni Samy; Rajkumar, Kanniah; Wang, Yanjie; Wang, Yu; Wang, Junhu; Anbalagan, Krishnamoorthy

    2015-10-01

    The present article is focused on recent developments toward the preparation of room temperature ferromagnetic nanocomposites using better photocatalytic performance. These nanocomposites were successfully prepared by a simple hydrothermal method and their molecular formulas were confirmed as Ti0.90Sn0.10O2 (S1), 0.2CuO-Ti0.73Sn0.06Cu0.21O2-δ (S2), and Ti0.82Sn0.09Fe0.09O2-δ (S3). The ICP, XRD, DRS, FTIR, Raman, XAFS, XPS, EPR, SEM-EDX, HRSEM, HRTEM, photoluminescence and vibrating sample magnetometric measurements were employed to characterize the phase structures, morphologies, optical and magnetic properties of the photocatalysts. The local structures of Sn4+ and Fe3+ were confirmed by 119Sn and 57Fe Mössbauer analysis. The photocatalytic activities of the samples were evaluated by the degradation of methyl orange in water under visible light irradiation. Among the samples, tin doped TiO2 (S1) showed the best photocatalytic performance and stability.

  15. Application of hydrothermal method derived titanate nanotubes as adsorbents.

    PubMed

    Lee, Chung-Kung; Liu, Shin-Shou; Chen, Huang-Chi

    2009-01-01

    Titanate nanotubes (TNT) derived from alkaline hydrothermal method are characterized by high specific surface area, specific pore volume, and ion-exchange capacity. They may be a promising and important adsorbent in the environmental protection. Although their applications in the fields of lithium ion batteries, dye-sensitized solar cell, photocatalysis, catalysts support, gas and humidity sensors, and ion exchange have been intensely studied during recent years, however, the researches concerning their potential application as an adsorbent are seldom reported. In this mini-review, we first highlight the effects of hydrothermal temperature and sodium content on the microstructures of hydrothermal method derived TNT, because the morphology and microstructure of TNT are highly dependent on the preparation conditions. Effects of the alterations of microstructures induced by the variation of hydrothermal temperature and sodium content on the dyes, heavy metal ions, and organic vapors adsorption characteristics of TNT are then introduced citing recent patents.

  16. Resistivity methods in exploration for hydrothermal resources

    SciTech Connect

    Jiracek, G.R.; Ruscetta, C.A.; Foley, D.

    1981-05-01

    The practical aspects of using dc resistivity in the exploration for hydrothermal resources are discussed. There are several reasons why low electrical resistivity is expected in hydrothermal aquifers but the association is not without pit falls. Besides outlining the reasons why resistivity has proven a successful geothermal exploration tool, a section on how resistivity is practiced is included. Here, the common electrode arrays are considered with their major advantages and disadvantages pointed out. The current status in resistivity interpretation schemes is touched upon with emphasis on computer modeling. Finally, a successful resistivity case history of a low-temperature resource at Las Alturas Estates, New Mexico is included to illustrate a specific resistivity exploration philosophy. The case history concludes with drilling results which are, of course, the ultimate test.

  17. Methods to enhance the characteristics of hydrothermally prepared slurry fuels

    DOEpatents

    Anderson, Chris M.; Musich, Mark A.; Mann, Michael D.; DeWall, Raymond A.; Richter, John J.; Potas, Todd A.; Willson, Warrack G.

    2000-01-01

    Methods for enhancing the flow behavior and stability of hydrothermally treated slurry fuels. A mechanical high-shear dispersion and homogenization device is used to shear the slurry fuel. Other improvements include blending the carbonaceous material with a form of coal to reduce or eliminate the flocculation of the slurry, and maintaining the temperature of the hydrothermal treatment between approximately 300.degree. to 350.degree. C.

  18. Optimization of process condition of nanosilica production by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Qisti, N.; Indrasti, N. S.; Suprihatin

    2016-11-01

    Bagasse ashes have high silica content thus it can be used in nanosilicaproduction to increase its benefit value. This study aimed to get the best time for synthesis and to determine the optimum synthesis time and temperature. This study used the hydrothermal method, a simple method with relatively low reaction temperature and provide a good chemical homogeneity. Time varieties in synthesizing silica were 8,10 and 12 hours, at the temperature of 150 °C. But the results were not as expected. Moreover, optimization of synthesis temperature and time used 4 hours at the temperature of 150 °C based on previous studies. Optimization was conducted using the Response Surface Methodology (RSM). Later, a testusing PSA (Particle Size Analyzer) was performed to obtain particle sizes and PDI values (Polydispersity Index). The results showed that the prediction model of temperature synthesis was 152.67 °C synthesis time of 6 hours, particle size of 276.288 nm and PDI value of 0.189642. The tests showed that the size of particle obtained was 330.39 nm and PDI value at 0.3580. Actual results and predicted results were not significant different.

  19. Simple Method for Culturing Anaerobes

    PubMed Central

    Davis, C. E.; Hunter, W. J.; Ryan, J. L.; Braude, A. I.

    1973-01-01

    A simple, effective method is needed for growing obligate anaerobes in the clinical laboratory. This report describes a pre-reduced anaerobic bottle that can be taken to the bedside for direct inoculation, provides a flat agar surface for evaluation of number and morphology of colonies, and can be incubated in conventional bacteriological incubators. Each anaerobic culture set consisted of two bottles containing brain heart infusion agar and CO2. Gentamicin sulfate (50 μg/ml) was added to one of these to inhibit facultative enteric bacilli. Comparison of the anaerobic bottles with an identical aerobic bottle which was also routinely inoculated permitted early identification of anaerobic colonies. Representative species of most anaerobic genera of proven pathogenicity for man have been isolated from this system during 10 months of routine use. Images PMID:4571657

  20. Direct synthesis of silver/polymer/carbon nanocables via a simple hydrothermal route

    SciTech Connect

    Jin Mingshang; Kuang Qin Jiang Zhiyuan; Xu Tao; Xie Zhaoxiong Zheng Lansun

    2008-09-15

    High-yield silver/polymer/carbon nanocables were synthesized via a one-step simple hydrothermal route by using silver chloride and glucose as precursors. High-resolution TEM and element mapping proved that as-prepared nanocables consist of a silver nanowire core, a polymer inner shell, and a graphitic carbon outer shell. A three-step growth mechanism was proposed to explain the growth of such three-layer nanocables, i.e. the formation of silver nanowires, the glycosidation of glucose molecules on silver nanowire surface and the carbonization of the outmost glycosidation layer. We believe that reaction temperature plays the key role in the polymerization of glucose and sequent surface-carbonization. - Graphical abstract: High-yield silver/polymer/carbon coaxial nanocables were synthesized via a one-step simple hydrothermal route by using silver chloride and glucose as precursors. Our experiments indicate that such novel nanostructures formed through the growth mechanism that the silver nanowires grow first, and then glycosidation of glucose occurs on the silver nanowire surfaces, and finally the partial carbonization occurs on the outmost surface of the polymer layer.

  1. Special fractal growth of dendrite copper using a hydrothermal method

    SciTech Connect

    Zheng Yan; Zhang Zhejuan; Guo Pingsheng; He Pingang; Sun Zhuo

    2011-08-15

    Special fractal dendrite Cu nanostructures have been synthesized through a simple hydrothermal method, and the effects of the volume ratio between glycerol and water and the concentration of H{sub 3}PO{sub 3} on the morphologies of dendrite Cu have been studied in detail. The Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD) have been used to characterize these Cu products. The results indicate that rhombic diamond and different morphologies of fractal dendrite were prepared because of the accumulation of Cu nuclei based on the diffusion-limited aggregation (DLA) and the nucleation-limited aggregation (NLA) model. Fortunately, symmetrical leaf-like dendrite Cu nanostructures different from Cu dendrites reported before have been obtained. Additionally, an explanation for the growth of fractal dendrite Cu has been discussed carefully. - Graphical abstract: Uniform dendritic Cu are grown through controlling V{sub glycerol/water} in range of 0.6-1.2 and the concentration of H{sub 3}PO{sub 3} in range of 0.06-0.3 M. The rhombic cluster Cu are obtained by decreasing the amount of glycerol. Highlights: > Volume ratio of glycerol/water and concentration of H{sub 3}PO{sub 3} were varied, respectively. > Morphologies of dendritic Cu have some changes. > Leaf-like and rhombic cluster Cu were obtained. > The concentration changes affect the aggregation of Cu crystallites. > The aggregation and crystallographic orientation cause leaf-like Cu nanostructures.

  2. A simple physical model for the internal structure of hydrothermal convection cells

    NASA Astrophysics Data System (ADS)

    Jupp, T.; Schultz, A.

    2003-04-01

    Using a simple physical model, we investigate how the nonlinear thermodynamic properties of water influence the steady-state structure of subseafloor hydrothermal convection cells. This constitutes an extension of our previous work (Jupp and Schultz, Nature, 2000) in which we considered how the properties of water influence the manner in which such a system approaches the steady state. Our model for steady state convection divides a convection cell into three zones - (i) recharge zone, (ii) reaction zone and (iii) discharge zone - and we consider the mass and energy balances within each zone. Central to our formulation is the concept of the `fluxibility' of the convecting fluid (Lister, Geophys. J. Int., 1995). (The `fluxibility' is a thermodynamic variable measuring the rate at which the fluid can transport thermal energy by bouyancy-driven flow). We derive a scaling analysis which shows how the lengthscales, residence times and total power output of the three zones within a hydrothermal system depend on the permeability k of the seafloor (assumed to be homogeneous) and the temperature Tp of the upwelling fluid. For realistic values of k and Tp the model reproduces plausible lengthscale estimates. In principle, our scalings could be used to constrain bulk permeability of the reaction and discharge zones if robust estimates of lengthscales or residence times could be made from active hydrothermal systems or fossil ophiolite systems. Seafloor observations suggest that fluid upwells at Tp ˜ 350o{C} and we show that this is the temperature at which the total power output of our model system is maximised. We therefore consider our results in the light of the `Malkus hypothesis' which states that convective systems tend to maximise the overall heat transport.

  3. Controllable Synthesis of Single-Crystalline CdO and Cd(OH)2Nanowires by a Simple Hydrothermal Approach

    PubMed Central

    2010-01-01

    Single-crystalline Cd(OH)2 or CdO nanowires can be selectively synthesized at 150 °C by a simple hydrothermal method using aqueous Cd(NO3)2 as precursor. The method is biosafe, and compared to the conventional oil-water surfactant approach, more environmental-benign. As revealed by the XRD results, CdO or Cd(OH)2 nanowires can be generated in high purity by varying the time of synthesis. The results of FESEM and HRTEM analysis show that the CdO nanowires are formed in bundles. Over the CdO-nanowire bundles, photoluminescence at ~517 nm attributable to near band-edge emission of CdO was recorded. Based on the experimental results, a possible growth mechanism of the products is proposed. PMID:20672033

  4. Simple mass production of zinc oxide nanostructures via low-temperature hydrothermal synthesis

    NASA Astrophysics Data System (ADS)

    Ghasaban, Samaneh; Atai, Mohammad; Imani, Mohammad

    2017-03-01

    The specific properties of zinc oxide (ZnO) nanoparticles have attracted much attention within the scientific community as a useful material for biomedical applications. Hydrothermal synthesis is known as a useful method to produce nanostructures with certain particle size and morphology however, scaling up the reaction is still a challenging task. In this research, large scale hydrothermal synthesis of ZnO nanostructures (60 g) was performed in a 5 l stainless steel autoclave by reaction between anionic (ammonia or sodium hydroxide) and cationic (zinc acetate dehydrate) precursors in low temperature. Hydrothermal reaction temperature and time were decreased to 115 °C and 2 or 6 h. In batch repetitions, the same morphologies (plate- and needle-like) with reproducible particle size were obtained. The nanostructures formed were analyzed by powder x-ray diffraction, Fourier-transform infrared spectroscopy, energy dispersive x-ray analysis, scanning electron microscopy and BET analysis. The nanostructures formed were antibacterially active against Staphylococcus aureus.

  5. Novel preparation of highly photocatalytically active copper chromite nanostructured material via a simple hydrothermal route

    PubMed Central

    Beshkar, Farshad; Zinatloo-Ajabshir, Sahar; Bagheri, Samira; Salavati-Niasari, Masoud

    2017-01-01

    Highly photocatalytically active copper chromite nanostructured material were prepared via a novel simple hydrothermal reaction between [Cu(en)2(H2O)2]Cl2 and [Cr(en)3]Cl3.3H2O at low temperature, without adding any pH regulator or external capping agent. The as-synthesized nanostructured copper chromite was analyzed by transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy, energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Results of the morphological investigation of the as-synthesized products illustrate that the shape and size of the copper chromite depended on the surfactant sort, reaction duration and temperature. Moreover, the photocatalytic behavior of as-obtained copper chromite was evaluated by photodegradation of acid blue 92 (anionic dye) as water pollutant. PMID:28582420

  6. Novel preparation of highly photocatalytically active copper chromite nanostructured material via a simple hydrothermal route.

    PubMed

    Beshkar, Farshad; Zinatloo-Ajabshir, Sahar; Bagheri, Samira; Salavati-Niasari, Masoud

    2017-01-01

    Highly photocatalytically active copper chromite nanostructured material were prepared via a novel simple hydrothermal reaction between [Cu(en)2(H2O)2]Cl2 and [Cr(en)3]Cl3.3H2O at low temperature, without adding any pH regulator or external capping agent. The as-synthesized nanostructured copper chromite was analyzed by transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy, energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Results of the morphological investigation of the as-synthesized products illustrate that the shape and size of the copper chromite depended on the surfactant sort, reaction duration and temperature. Moreover, the photocatalytic behavior of as-obtained copper chromite was evaluated by photodegradation of acid blue 92 (anionic dye) as water pollutant.

  7. Single crystalline ZnO nanorods grown by a simple hydrothermal process

    SciTech Connect

    Pei, L.Z.; Zhao, H.S.; Tan, W.; Yu, H.Y.; Chen, Y.W.; Zhang Qianfeng

    2009-09-15

    Single crystalline ZnO nanorods with wurtzite structure have been prepared by a simple hydrothermal process. The microstructure and composition of the products were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM, energy dispersive X-ray spectrum (EDS) and Raman spectrum. The nanorods have diameters ranging from 100 nm to 800 nm and length of longer than 10 {mu}m. Raman peak at 437.8 cm{sup -1} displays the characteristic peak of wurtzite ZnO. Photoluminescence (PL) spectrum shows a blue light emission at 441 nm, which is related to radiative recombination of photo-generated holes with singularly ionized oxygen vacancies.

  8. Photocatalytic properties of ZnO micromaterials prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Gao, Junshan; Huang, Shaofu; Luo, Pengfei; Huang, Shuanghe

    2016-12-01

    ZnO microrods were prepared by a simple and inexpensive hydrothermal method. The structure, morphology and optical properties of the micromaterials were characterized by XRD, FE-SEM and UV-Vis spectroscopy. The FE-SEM micrographs indicated that the sizes of the microrods were 0.2-1 μm in width and 2-5 μm in length. With methyl orange as a model degradation target, photocatalytic performance of the microrods under ultraviolet radiation was evaluated. The results indicate that the photocatalytic activity of ZnO microrods was satisfactory even under low power ultraviolet irradiation.

  9. Textured catalysts, methods of making textured catalysts, and methods of catalyzing reactions conducted in hydrothermal conditions

    DOEpatents

    Werpy, Todd [West Richland, WA; Wang, Yong [Richland, WA

    2003-12-30

    A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.

  10. A simple method of accelerating monotonic sequences

    NASA Astrophysics Data System (ADS)

    Sarkar, B.; Bhattacharyya, K.

    1993-03-01

    A converse of the well known Cesaro method has been demonstrated to accelerate successfully various monotonic sequences of practical concern. The method is simple, regular and particular apt for low-order data. Pilot calculations highlighting the workability in varying practical contexts involve atomic lattice constants (cubic), typical nuclear attraction integrals in molecular calculations and critical parameters in phase transitions.

  11. Hydroxyapatite-phosphonoformic acid hybrid compounds prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Turki, Thouraya; Othmani, Masseoud; Bantignies, Jean-Louis; Bouzouita, Khaled

    2014-01-01

    Hydroxyapatites were prepared in the presence of different amounts of phosphonoformic acid (PFA) via the hydrothermal method. The obtained powders were characterized through chemical analysis, XRD, IR, 31P MAS-NMR, TEM, and TG-TDA. The XRD showed that the PFA did not affect the apatite composition. Indeed, only a reduction of the crystallite size was noted. After grafting of PFA, the IR spectroscopy revealed the appearance of new bands belonging to HPO42- and carboxylate groups of the apatite and organic moiety, respectively. Moreover, the 31P MAS-NMR spectra exhibited a peak with a low intensity assigned to the terminal phosphonate group of the organic moiety in addition to that of the apatite. Based on these results, a reaction mechanism involving the surface hydroxyl groups (tbnd Casbnd OH) of the apatite and the carboxyl group of the acid was proposed.

  12. Phosphonate-hydroxyapatite hybrid compounds prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Agougui, H.; Aissa, A.; Maggi, S.; Debbabi, M.

    2010-12-01

    Calcium hydroxyapatite (CaHAp) was prepared in the presence of two alkylphosphonates, the tert-butyl phosphonic acid TBPOH and the 2-carboxyletylphosphonic acid 2-CEPA, by hydrothermal method at 120 °C for 15 h. The modification of hydroxyapatite by grafting organic moieties is confirmed by IR and NMR MAS ( 1H and 31P) spectroscopy and chemical analysis. X-ray powder diffraction patterns show that the incorporation of organic moieties induces a significant loss of the material crystallinity and a clear increase of the unit cell lattice parameter a as function of 2-CEPA grafting rate. The specific surface area (SSA) increases with increasing phosphonate amount especially for 2-CEPA. All techniques show the lower reactivity of TBPOH due to the steric effects of tert-butyl, whereas the 2-CEPA with a linear chain and double acidic functions is more reactive and can replace the OH - groups of the apatitic structure.

  13. Simple colorimetric method determines uranium in tissue

    NASA Technical Reports Server (NTRS)

    Doran, D.; Frigerio, N. A.

    1967-01-01

    Simple colorimetric micromethod determines concentrations of uranium in tissue. The method involves dry ashing organic extraction, and colorimetric determination of uranyl ferrocyanide. This uranium determination technique could be used in agricultural research, tracer studies, testing of food products, or medical research.

  14. A Simple Weighing Method for Spherical Cells.

    PubMed

    Zhao, Qili; Shirinzadeh, Bijan; Cui, Maosheng; Sun, Mingzhu; Zhao, Xin

    2015-08-01

    This article presents a simple weighing method for spherical cells to avoid the high cost of correlated devices in traditional cell-weighing methods. In this method, the constant falling speeds of the spherical objects in liquid are derived to estimate their masses online. Using this method, the detected density of one type of microbead is highly in accordance with the known value. This method is proved to be capable of detecting tiny variations of the cell mass (at least within 1% of the cell mass). Finally, the proposed method is applied in nuclear transplantation operations, and, for the first time, the proper amount of the removed cytoplasm in porcine enucleation is estimated. The proposed method is able to weigh cells with a success rate of 92% at an average speed of 22 s/cell, and it can be performed on traditional microoperation systems, which makes it easily applicable in biological applications. © 2015 Society for Laboratory Automation and Screening.

  15. A simple method for focal length measurement

    NASA Astrophysics Data System (ADS)

    Ma, Hua; Ren, Huan; Zhang, Lin; Shi, Zhengdong; Yuan, Quan; Yang, Yi

    2016-09-01

    A simple method for focal length measurement based on image processing is demonstrated and discussed. The collimated beam, detector, motorized translation stage and computer make up of this test system. The two spots pass through the tested lens is accepted by detector, which is transferred twice by motorized translation stage. By acquired the difference of two spots by image processing, the focal length of the tested lens can be gained. The error sources in the measurement are analyzed. Then the results of experiment show that the relative error was 0.1%. This method can be used in workshop and labs for its convenience and low cost.

  16. CuO urchin-nanostructures synthesized from a domestic hydrothermal microwave method

    SciTech Connect

    Keyson, D.; Volanti, D.P.; Cavalcante, L.S. Simoes, A.Z.; Varela, J.A.; Longo, E.

    2008-03-04

    This letter reports the synthesis of CuO urchin-nanostructures by a simple and novel hydrothermal microwave method. The formation and growth of urchin-nanostructures is mainly affected by the addition of polyethylene glycol (PEG). The hierarchical malachite particles are uniform spheres with a diameter of 0.7-1.9 {mu}m. CuO urchin-nanostructures were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FEG-SEM) and nitrogen adsorption (BET). The specific surface area of the CuO nanostructured microspheres was about 170.5 m{sup 2}/g. A possible mechanism for the formation of such CuO urchin-nanostructures is proposed.

  17. Development of observation method for hydrothermal flows with acoustic video camera

    NASA Astrophysics Data System (ADS)

    Mochizuki, M.; Asada, A.; Kinoshita, M.; Tamura, H.; Tamaki, K.

    2011-12-01

    DIDSON (Dual-Frequency IDentification SONar) is acoustic lens-based sonar. It has sufficiently high resolution and rapid refresh rate that it can substitute for optical system in turbid or dark water where optical systems fail. Institute of Industrial Science, University of Tokyo (IIS) has understood DIDSON's superior performance and tried to develop a new observation method based on DIDSON for hydrothermal discharging from seafloor vent. We expected DIDSON to reveal whole image of hydrothermal plume as well as detail inside the plume. In October 2009, we conducted seafloor reconnaissance using a manned deep-sea submersible Shinkai6500 in Central Indian Ridge 18-20deg.S, where hydrothermal plume signatures were previously perceived. DIDSON was equipped on the top of Shinkai6500 in order to get acoustic video images of hydrothermal plumes. The acoustic video images of the hydrothermal plumes had been captured in three of seven dives. These are only a few acoustic video images of the hydrothermal plumes. We could identify shadings inside the acoustic video images of the hydrothermal plumes. Silhouettes of the hydrothermal plumes varied from second to second, and the shadings inside them varied their shapes, too. These variations corresponded to internal structures and flows of the plumes. We are analyzing the acoustic video images in order to deduce information of their internal structures and flows in plumes. On the other hand, we are preparing a tank experiment so that we will have acoustic video images of water flow under the control of flow rate. The purpose of the experiment is to understand relation between flow rate and acoustic video image quantitatively. Results from this experiment will support the aforementioned image analysis of the hydrothermal plume data from Central Indian Ridge. We will report the overview of the image analysis and the tank experiments, and discuss possibility of DIDSON as an observation tool for seafloor hydrothermal activity.

  18. Simple Spectrophotometric Methods for Standardizing Ayurvedic Formulation

    PubMed Central

    Vador, N.; Vador, B.; Hole, Rupali

    2012-01-01

    Traditional medicines are effective but the standardization of Ayurvedic formulations is essential in order to assess the quality of drugs, based on the concentration of their active principles. Department of AYUSH has given preliminary guidelines for standardizing these conventional formulations, for uniformity of batches in production of Ayurvedic formulation and it is necessary to develop methods for evaluation. The present work is an attempt to standardize asav-arishta, the traditional Ayurvedic formulation using simple, non-expensive spectrophotometric methods. The various parameters performed included total phenolics, total flavonoids, total alkaloids and total saponins, also included pH, sugar %, alcohol content and specific gravity. The results obtained may be considered as tools for assistance to the regulatory authorities, scientific organizations and manufacturers for developing standards. PMID:23325998

  19. Atraumatic Flexor tendon retrieval- a simple method

    PubMed Central

    2013-01-01

    Background Zone 2 flexor tendon injuries still represent a challenging problem to hand surgeons despite the well developed surgical techniques and suture materials. Meticulous surgical repair with atraumatic handling of the severed tendon stumps and minimal damage to the tendon sheath are particularly important to prevent postoperative adhesions and ruptures in this area. In zone 2 flexor tendon injuries proximal to the vinculas, the cut ends of the flexor tendons retract to the palm with muscle contraction. To retrieve the severed proximal flexor tendon under tendon sheath and pulley system is very difficult without damaging these structures. Many techniques are described in the literature for the delivery of the retracted proximal tendon stump to the repair site. Methods In this report we would like to present a simple and relatively atraumatic technique that facilitates passing of the retracted flexor tendon through the pulleys in zone 2. We sutured the proximal tendon stump at the distal palmar crease with 3–0 polypropylene suture and used a 14 gauge plastic feeding tube, acting like a conduit for the passage of straightened needle to the finger. Results We have used this technique 21 times without any complication in our clinic. We have not seen any suture breakage during the passage or needle breakage due to the bending of the needle. Conclusions We have found this technique is very simple and very effective in retrieving the retracted tendon stump without causing undue damage to the tendon stump or tendon sheath. PMID:24040913

  20. Synthesis and characterization of nanosized MnZn ferrites via a modified hydrothermal method

    NASA Astrophysics Data System (ADS)

    Li, Mingling; Liu, Xiansong; Xu, Taotao; Nie, Yu; Li, Honglin; Zhang, Cong

    2017-10-01

    Nanosized MnZn ferrite particles, with narrow size distribution, regular morphology and high saturation magnetization have been synthesized via a modified hydrothermal method. This modified hydrothermal method involves a chemical co-precipitation of hydroxides under a vacuum condition using potassium hydroxide as precipitating agent, followed by a separate hydrothermal process. The microstructure and magnetic properties of the synthesized nanoparticles were investigated by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM). The effects of different synthesis conditions (excess ratio of precipitating agent and hydrothermal reaction time) on the microstructure and magnetic properties of the as-synthesized nanoparticles were discussed. The magnetic measurements indicated that the obtained samples were superparamagnetic in nature at room temperature. Moreover, the MnZn ferrite nanoparticles with excellent magnetic performance could be synthesized at 180 °C for a short reaction time (3 h).

  1. Rare Earth Oxide Fluoride Nanoparticles And Hydrothermal Method For Forming Nanoparticles

    DOEpatents

    Fulton, John L.; Hoffmann, Markus M.

    2003-12-23

    A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

  2. Rare earth oxide fluoride nanoparticles and hydrothermal method for forming nanoparticles

    DOEpatents

    Fulton, John L [Richland, WA; Hoffmann, Markus M [Richland, WA

    2001-11-13

    A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

  3. Controlled synthesis of α-Al2O3 via the hydrothermal-pyrolysis method

    NASA Astrophysics Data System (ADS)

    Li, Zhao; Wu, Kunyao; Cao, Jing; Wang, Yongfeng

    2017-06-01

    Taking aluminum sulfate and urea as the raw materials produce α-Al2O3 by employing the hydrothermal-pyrolysis method. The study analyzes the characterization of the products by XRD and SEM, The results indicate as follows: after 6 hours’ hydrothermal reaction in the 120°C water, with the aluminum sulfate and urea as the raw materials, spherical α-Al2O3 can be obtained through calcination at 1200°C.

  4. Synthesis of KNbO3 nanorods by hydrothermal method.

    PubMed

    Wang, Guozhong; Yu, Yingda; Grande, Tor; Einarsrud, Mari-Ann

    2009-02-01

    Potassium niobate (KNbO3) nanorods were prepared from Nb2O5 powder by hydrothermal synthesis in KOH solution at 180 degrees C for 48 h using sodium dodecyl sulfate surfactant. The products were characterized by X-ray diffraction as well as scanning and transmission electron microscopy. The KNbO3 nanorods were shown to have orthorhombic crystal structure and were 100-300 nm in diameter and up to 5 microm long. The addition of surfactant changed the product morphology from agglomerated particles to nanorods. A possible mechanism for the formation of the KNbO3 nanorods is briefly discussed.

  5. Interbasin Flux Measurements Using Simple Methods

    SciTech Connect

    John Watson; Daniel Freeman

    2005-01-13

    The Vertical Transport and Mixing (VTMX) campaign, sponsored by the US Department of Energy, took place in the Salt Lake Valley during October, 2000. The purpose of VTMX was to further understanding of meteorological processes that govern vertical transport and mixing in complex terrain, particularly during nocturnal stable periods and their morning and evening transition periods. These meteorological processes were the subject of numerous sponsored studies during VTMX. The Salt Lake (Salt Lake City) Basin and the Utah Basin to its south are separated by the Traverse Range. Near-surface airflow between the basins is channeled through the Jordan Narrows, also the channel for the Jordan River that flows from the Utah Basin into Salt Lake via the Salt Lake Basin. Jordan Narrows is thus a potentially significant corridor for pollutant transport between the two basins. This paper describes simple and direct pollutant (PM{sub 10}) measurements, with concurrent continuous meteorological monitoring, to characterize pollutant transport between the two basins via low-level stable nocturnal drainage flow, with an emphasis on its vertical variability when mixing is limited. The Jordan Narrows has similarities to other transport corridors where direct in-corridor monitoring of pollutant flux might enhance pollution forecasts during transport conditions. Thus their more general objective is to assess the usefulness of direct methods to characterize pollutant flux in similar environments.

  6. Controlled synthesis of BiVO{sub 4} with multiple morphologies via an ethylenediamine-assisted hydrothermal method

    SciTech Connect

    Qi, Xuemei; Zhu, Xinyuan; Wu, Jiang; Wu, Qiang; Li, Xian; Gu, Miaoli

    2014-11-15

    Graphical abstract: BiVO{sub 4} samples with various morphologies were synthesized via a simple ethylenediamine (EN) assisted hydrothermal route. One of the mixed crystal phase with spherical and porous morphology showed excellent photocatalytic activity and about 90% Rhodamine B was degraded after 140 min visible light irradiation. - Highlights: • BiVO{sub 4} samples with various morphologies were synthesized by hydrothermal method. • Ethylenediamine mainly acts as alkaline source to adjust pH values of precursor. • BiVO{sub 4} with spherical morphology has excellent photocatalytic activity. - Abstract: In this work, BiVO{sub 4} particles with different crystal structures and morphologies including hexahedral, spherical porous and hyperbranched ones were fabricated in the presence of ethylenediamine by hydrothermal process. The as-fabricated samples were well characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and ultraviolet–visible absorption spectroscopy. The results showed that the morphology and crystal structure of BiVO{sub 4} particles could be well controlled by only changing the ethylenediamine content in the deionized water solution. Photocatalytic activity of the samples was evaluated by the degradation of Rhodamine B under visible-light irradiation. It was shown that BiVO{sub 4} sample with spherical porous morphology and mixed crystal phase exhibited the best photocatalytic performance after optimizing the ethylenediamine content. The best degradation ratio of Rhodamine B could reach about 87% after 140 min visible-light irradiation.

  7. A simple method for defining malaria seasonality

    PubMed Central

    2009-01-01

    Background There is currently no standard way of defining malaria seasonality, resulting in a wide range of definitions reported in the literature. Malaria cases show seasonal peaks in most endemic settings, and the choice and timing for optimal malaria control may vary by seasonality. A simple approach is presented to describe the seasonality of malaria, to aid localized policymaking and targeting of interventions. Methods A series of systematic literature reviews were undertaken to identify studies reporting on monthly data for full calendar years on clinical malaria, hospital admission with malaria and entomological inoculation rates (EIR). Sites were defined as having 'marked seasonality' if 75% or more of all episodes occurred in six or less months of the year. A 'concentrated period of malaria' was defined as the six consecutive months with the highest cumulative proportion of cases. A sensitivity analysis was performed based on a variety of cut-offs. Results Monthly data for full calendar years on clinical malaria, all hospital admissions with malaria, and entomological inoculation rates were available for 13, 18, and 11 sites respectively. Most sites showed year-round transmission with seasonal peaks for both clinical malaria and hospital admissions with malaria, with a few sites fitting the definition of 'marked seasonality'. For these sites, consistent results were observed when more than one outcome or more than one calendar year was available from the same site. The use of monthly EIR data was found to be of limited value when looking at seasonal variations of malaria transmission, particularly at low and medium intensity levels. Conclusion The proposed definition discriminated well between studies with 'marked seasonality' and those with less seasonality. However, a poor fit was observed in sites with two seasonal peaks. Further work is needed to explore the applicability of this definition on a wide-scale, using routine health information system data

  8. A simple, one-step hydrothermal approach to durable and robust superparamagnetic, superhydrophobic and electromagnetic wave-absorbing wood

    NASA Astrophysics Data System (ADS)

    Wang, Hanwei; Yao, Qiufang; Wang, Chao; Fan, Bitao; Sun, Qingfeng; Jin, Chunde; Xiong, Ye; Chen, Yipeng

    2016-10-01

    In this work, lamellar MnFe2O4 was successfully planted on a wood surface through the association of hydrogen bonds via the one-pot hydrothermal method. Simultaneously, the fluoroalkylsilane (FAS-17) on the surface of the MnFe2O4 layer formed long-chain or network macromolecules through a poly-condensation process and provided a lower surface energy on the wood surface. The MnFe2O4/wood composite (FMW) presented superior superparamagnetism, superhydrophobicity and electromagnetic wave absorption performance. The results indicated a saturation magnetization of the FMW with excellent superparamagnetism of 28.24 emu·g‑1. The minimum value of reflection loss of the FMW reached ‑8.29 dB at 16.39 GHz with a thickness of 3 mm. Even after mechanical impact and exposure to corrosive liquids, the FMW still maintained a superior superhydrophobicity performance.

  9. A simple, one-step hydrothermal approach to durable and robust superparamagnetic, superhydrophobic and electromagnetic wave-absorbing wood

    PubMed Central

    Wang, Hanwei; Yao, Qiufang; Wang, Chao; Fan, Bitao; Sun, Qingfeng; Jin, Chunde; Xiong, Ye; Chen, Yipeng

    2016-01-01

    In this work, lamellar MnFe2O4 was successfully planted on a wood surface through the association of hydrogen bonds via the one-pot hydrothermal method. Simultaneously, the fluoroalkylsilane (FAS-17) on the surface of the MnFe2O4 layer formed long-chain or network macromolecules through a poly-condensation process and provided a lower surface energy on the wood surface. The MnFe2O4/wood composite (FMW) presented superior superparamagnetism, superhydrophobicity and electromagnetic wave absorption performance. The results indicated a saturation magnetization of the FMW with excellent superparamagnetism of 28.24 emu·g−1. The minimum value of reflection loss of the FMW reached −8.29 dB at 16.39 GHz with a thickness of 3 mm. Even after mechanical impact and exposure to corrosive liquids, the FMW still maintained a superior superhydrophobicity performance. PMID:27748420

  10. Methods and apparatus for catalytic hydrothermal gasification of biomass

    DOEpatents

    Elliott, Douglas C.; Butner, Robert Scott; Neuenschwander, Gary G.; Zacher, Alan H.; Hart, Todd R.

    2012-08-14

    Continuous processing of wet biomass feedstock by catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent separation of sulfur contaminants, or combinations thereof. Treatment further includes separating the precipitates out of the wet feedstock, removing sulfur contaminants, or both using a solids separation unit and a sulfur separation unit, respectively. Having removed much of the inorganic wastes and the sulfur that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

  11. Application of Hyperspectral Methods in Hydrothermal Mineral System Studies

    NASA Astrophysics Data System (ADS)

    Laukamp, Carsten; Cudahy, Thomas; Gessner, Klaus; Haest, Maarten; Cacetta, Mike; Rodger, Andrew; Jones, Mal; Thomas, Matilda

    2010-05-01

    hyperspectral mineral mapping of contaminating, carbonate- or clay-rich zones helped to better constrain the ore zones and the genesis of the mineral system. Airborne hyperspectral data covering about 2500 km2 were obtained from the Eastern Goldfields Superterrane (Yilgarn Craton, Western Australia), which is highly prospective for Archean Au as well as komatiite associated Fe-Ni sulphide mineralisation. In this project hyperspectral airborne data allowed not only the remote mapping of mafic and ultramafic rocks, which are among the main host rocks for Archean Au deposits in the study area, but also the remote mapping of hydrothermal alteration patterns and various geochemical signatures related to the structurally controlled Au mineralisation down to a 4.5 m pixel size. We can reconstruct fluid pathways and their intersections with steep physicochemical gradients, where Au deposition presumably took place, by combining hyperspectral remote sensing with hyperspectral drill core data in 3D mineral maps. White mica mineral maps as well as mineral maps based on the abundance and composition of MgOH and FeOH bearing silicates are the main products for a semi-quantitative assessment of the key alteration minerals in this project. In the southern Selwyn Range, Mount Isa Inlier, Queensland, hyperspectral mineral maps, such as "ferric oxide abundance", "white mica abundance" and "white mica composition", were integrated with geophysical datasets (total magnetic intensity, ternary radiometric imagery). The integration of the datasets enabled us to construct a comprehensive fluid flow model contributing to our understanding of iron-oxide Cu-Au deposits in this region, identifying the source, pathway and depositional sites, which are in good accordance with known deposits. 3D mineral maps derived from hyperspectral methods can distinctly improve our understanding of mineral systems. The advantages of hyperspectral techniques over conventional exploration methods include: (1) the fast and

  12. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  13. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  14. Synthesis and characterization of mesoporous MgO by template-free hydrothermal method

    SciTech Connect

    Cui, Hongmei; Wu, Xiaofeng; Chen, Yunfa; Boughton, R.I.

    2014-02-01

    Highlights: • A simple synthesis of porous MgO with diameter size from 3 to 10 μm without any templates. • Effect of temperature and time were investigated. • Systematic characterization by TG/DTA, XRD, SEM, TEM, and nitrogen adsorption–desorption isotherm of MgO. • A possible formation and crystal growth mechanism of mesopores MgO is proposed. - Abstract: Mesoporous MgO particles have been synthesized through a novel template-free hydrothermal co-precipitation method using a Mg(NO{sub 3}){sub 2} solution as the magnesium source and NaCO{sub 3} as precipitant. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N{sub 2} adsorption–desorption analysis. The results indicate that the MgO samples have a disordered mesoporous structure, a large BET surface area, and a large pore volume. The effect of reaction temperature on the MgO product BET surface area was studied. A possible formation and crystal growth mechanism for mesoporous MgO is proposed.

  15. Hydrothermal method of synthesis of rare-earth tantalates and niobates

    DOEpatents

    Nyman, May D; Rohwer, Lauren E.S.; Martin, James E

    2012-10-16

    A hydrothermal method of synthesis of a family of rare-earth Group 5 oxides, where the Group 5 oxide is a niobate or tantalate. The rare-earth Group 5 oxides can be doped with suitable emitter ions to form nanophosphors.

  16. Optical characteristics of ZnO single crystal grown by the hydrothermal method

    SciTech Connect

    Chen, G. Z.; Yin, J. G. E-mail: yjg@siom.ac.cn; Zhang, L. H.; Zhang, P. X.; Wang, X. Y.; Liu, Y. C.; Zhang, C. L.; Gu, S. L.; Hang, Y.

    2015-12-15

    ZnO single crystals have been grown by the hydrothermal method. Raman scattering and Photoluminescence spectroscopy (PL) have been used to study samples of ZnO that were unannealed or annealed in different ambient gases. It is suggested that the green emission may originate from defects related to copper in our samples.

  17. Effect of precursor concentration on the structural and optical properties of ZnO nanorods prepared by hydrothermal method

    SciTech Connect

    Lestari, Amie; Iwan, S.; Djuhana, Dede; Imawan, Cuk; Harmoko, Adhi; Fauzia, Vivi

    2016-04-19

    Zinc oxide (ZnO) nanorods has attractive properties for nanoscale optoelectronic applications, such as optical sensors, ultraviolet laser diodes, and photodetectors. ZnO nanorods, can be fabricated by simple and low cost chemical approach, such as hydrothermal method. In this method, the morphology, microstructure, optical and electrical properties of ZnO nanorods are highly determined by process parameters such as solvent, deposition time, deposition temperature as well as annealing condition. In this paper we report the fabrication of ZnO nanorods that were grown on transparent conducting indium tin oxide coated glass substrates. Initially, ZnO seed layers were deposited on heated substrates with temperature of 450 °C using ultrasonic spray pyrolysis method with frequency of 1.7 MHz and then grown by hydrothermal method with three different precursor concentrations, namely 0.02 M, 0.06 M, and 0.1 M. The surface morphology and structure were investigated by field emission scanning electron microscope (FESEM) and x-ray diffraction (XRD), while the optical properties were observed by photoluminescence (PL) and and UV VIS reflectance spectroscopy.

  18. A vapor phase hydrothermal modification method converting a honeycomb structured hybrid film into photoactive TiO2 film.

    PubMed

    Zhao, Huijun; Shen, Yanming; Zhang, Shanqing; Zhang, Haimin

    2009-09-15

    Transforming an organic/inorganic hybrid material into a pure inorganic material without losing its original structure is of interest for a range of applications. In this work, a simple and effective vapor phase hydrothermal method was developed to transform a 3D honeycomb structured PS/TTIP hybrid film into a photoactive TiO2 film without dismantling the originally templated 3D structure. The method utilizes the vapor phase hydrothermal process to create titania network/clusters with sufficient mechanical strength via the formation of Ti-oxo bridges. The organic components of the sample can be removed by means of pyrolysis while perfectly maintaining the original 3D honeycomb structure. The resultant film can be directly used for photocatalysis applications and could be further modified for other applications. In principle, this method can be used to preserve 3D structures of other organic/inorganic hybrid films during their conversion to pure inorganic films via a pyrolysis process, if mechanically strong networks can be formed as a result of hydrolysis reactions. The ability to preserve the preferred 3D structure during the subsequent conversion processes enables realization of the full benefit of unique architectures created by a templating method.

  19. Charge reduction in a vermiculite by acid and hydrothermal methods: a comparative study.

    PubMed

    Cristiano, D V; Campos, A M; Molina, R

    2005-10-13

    A comparative study on acid and hydrothermal methods as ways to reduce interlamellar charge has been carried out on a vermiculite. This study showed that the application of the hydrothermal treatment as a previous step to pillaring the vermiculites, reported here for the first time, is a new route to obtain the porous material with a particular interest as heterogeneous catalysts, starting from mineral clays with a high density of charge. Modified clays have been characterized by atomic absorption, emission spectrograph, X-ray diffraction, cation-exchange capacity, total acidity, infrared spectroscopy (DRIFT), and nitrogen adsorption. The results have shown that all solids have been structurally modified. However, acid and hydrothermal methods showed different behavior. For the vermiculite, the hydrothermal treatment did not produce major differences in terms of the crystalline structure, whereas the acid method caused severe structural damage. The catalytic properties have been tested over Pt-impregnated samples (1%) using the hydroisomerization of heptane. Important catalytic activity was established for all solids with high selectivity regarding the isomer products.

  20. NiO nanowall array prepared by a hydrothermal synthesis method and its enhanced electrochemical performance for lithium ion batteries

    SciTech Connect

    Cao, F.; Pan, G.X.; Tang, P.S.; Chen, H.F.

    2013-03-15

    Graphical abstract: Self-supported NiO nanowall array is fabricated by a facile hydrothermal synthesis method and exhibits noticeable Li ion battery performance with good cycle life and high capacity. Highlights: ► NiO nanowall array is prepared by a hydrothermal synthesis method. ► NiO nanowall array with high capacity as anode material for Li ion battery. ► Nanowall array structure is favorable for fast ion/electron transfer. - Abstract: Free-standing quasi-single-crystalline NiO nanowall array is successfully fabricated via a simple hydrothermal synthesis method. The as-prepared NiO film exhibits a highly porous nanowall structure composed of many interconnected nanoflakes with thicknesses of ∼20 nm. The NiO nanowalls arrange vertically to the substrate resulting in the formation of extended porous net-like structure with pores of 30–300 nm. As anode material for lithium ion batteries, the quasi-single-crystalline NiO nanowall array exhibits pretty good electrochemical performances with high capacity, weaker polarization, higher coulombic efficiency and better cycling performance as compared to the dense polycrystalline NiO film. The quasi-single-crystalline NiO nanowall array presents an initial coulombic efficiency of 76% and good cycling life with a capacity of 564 mAh g{sup −1} at 0.5 A g{sup −1} after 50 cycles, higher than that of the dense polycrystalline NiO film (358 mAh g{sup −1}). The enhanced performance is due to the unique nanowall array structure providing faster ion/electron transport and better morphological stability.

  1. Action Research Methods: Plain and Simple

    ERIC Educational Resources Information Center

    Klein, Sheri R., Ed.

    2012-01-01

    Among the plethora of action research books on the market, there is no one text exclusively devoted to understanding how to acquire and interpret research data. Action Research Methods provides a balanced overview of the quantitative and qualitative methodologies and methods for conducting action research within a variety of educational…

  2. Action Research Methods: Plain and Simple

    ERIC Educational Resources Information Center

    Klein, Sheri R., Ed.

    2012-01-01

    Among the plethora of action research books on the market, there is no one text exclusively devoted to understanding how to acquire and interpret research data. Action Research Methods provides a balanced overview of the quantitative and qualitative methodologies and methods for conducting action research within a variety of educational…

  3. A study of thermal properties of sodium titanate nanotubes synthesized by microwave-assisted hydrothermal method

    SciTech Connect

    Preda, Silviu; Rutar, Melita; Umek, Polona; Zaharescu, Maria

    2015-11-15

    Highlights: • The microwave-assisted hydrothermal route was used for titanate nanotubes synthesis. • Conversion to single-phase nanotube morphology completes after 8 h reaction time. • The nanotube morphology is stable up to 600 °C, as determined by in-situ XRD and SEM. • Sodium ions migrate to the surface due to thermal motion and structure condensation. - Abstract: Sodium titanate nanotubes (NaTiNTs) were synthesized by microwave-assisted hydrothermal treatment of commercial TiO{sub 2}, at constant temperature (135 °C) and different irradiation times (15 min, 1, 4, 8 and 16 h). The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and specific surface area measurements. The irradiation time turned out to be the key parameter for morphological control of the material. Nanotubes were observed already after 15 min of microwave irradiation. The analyses of the products irradiated for 8 and 16 h confirm the complete transformation of the starting TiO{sub 2} powder to NaTiNTs. The nanotubes are open ended with multi-wall structures, with the average outer diameter of 8 nm and specific surface area up to 210 m{sup 2}/g. The morphology, surface area and crystal structure of the sodium titanate nanotubes synthesized by microwave-assisted hydrothermal method were similar to those obtained by conventional hydrothermal method.

  4. Propidium Monoazide-based Method for Identifying Phylogenetic Association of Necromass Near Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Ramírez, Gustavo; Edwards, Katrina

    2014-05-01

    Black Smoker hydrothermal systems are geologically driven systems located near subduction zones and spreading centers associated with plate margins. The high temperature and low pH of fluids that are often associated with basalt-hosted hydrothermal systems select for unique microbial communities primarily comprised of prokaryotes capable of S and Fe cycling. High temperature fluids, where temperatures exceed 300° C, are likely to have a lethal effect on transient deep water planktonic communities and, over long temporal scales, may influence the molecular composition of pelleted necromass aggregates near the chimney system. We have developed a method for discriminative sequencing permitting intra vs. extracellular 16S rDNA sequencing to reveal community differences between biologically-relevant and necromass-associated DNA. This method has only recently been applied to marine environments and, here, we propose its use as relevant tool for studying the molecular ecology of high temperature hydrothermal systems, as physical drivers of massive transient community die offs and associated detrital 16S rDNA community shifts. Ultimately, we aim to understand the fraction of 16S rDNA communities that do not represent living taxa, or the information-containing fraction of total necromass pool, to better frame ecological hypotheses regarding environmental biogeochemical cycling in hydrothermal system environments.

  5. Taal volcanic hydrothermal system (Philippines) inferred by electromagnetic and other geophysical methods

    NASA Astrophysics Data System (ADS)

    Zlotnicki, Jacques; Toutain, Jean Paul; Sasai, Yoichi; Villacorte, Egardo; Bernard, Alain; Fauquet, Frederic; Nagao, Toshiyatsu

    2010-05-01

    On volcanoes which display hydrothermal/magmatic unrests, Electromagnetic (EM) methods can be combined with geochemical (GC) and thermal methods. The integration of these methods allows to image in detail hydrothermal systems, to find out possible scenarios of volcanic unrest, and to monitor the on-going activity with knowledge on the sources of heat, gas and fluid transfers. Since the 1990's the volcano shows recurrent periods of seismic activity, ground deformation, hydrothermal activity, and surface activity (geysers). Combined EM and GC methods noticeably contribute to map in detail the hydrothermal system and to analyse the sources of the activity: - Total magnetic field mapping evidences demagnetised zones over the two main areas forming the hydrothermal system (in the northern part of Main crater (MC)). These low magnetized areas are ascribed to thermal sources located at some hundreds metres of depth, - Self-potential surveys, delineate the contours of the fluids-heat transfer, and the northern and southern structural discontinuities enclosing the hydrothermal system, - Ground temperature gradient measurements evidence the distinctive heat transfer modes, from low fluxes related to soil temperature dominated by solar input to extremely high temperature gradients of 1200 °C m-1 or to more related to magmatic fluids. - Ground temperature and surface temperature of central acidic lake calculated by Thermal Aster imaging highlight the location of the most active ground fissures, outcrops and diffuse areas. Higher and larger anomalies are observed in the northern part of MC. A rough estimation of the thermal discharge in the northern part of the volcano gives 17 MW. - CO2 concentrations and fluxes from soil supply inform on fluids origin and on local processes operating along active fractures. Much higher carbon dioxide fluxes at MC sites confirm that the source of Taal activity is presently located in the northern part of the crater. - Heat and fluids release

  6. Influence of surfactants on the morphology of SnO{sub 2} nanocrystals prepared via a hydrothermal method

    SciTech Connect

    Wang Mi; Gao Yanfeng; Dai Lei; Cao Chuanxiang; Guo Xuhong

    2012-05-15

    Nanoscaled SnO{sub 2} with different morphologies has been synthesized via a simple hydrothermal process at 180 Degree-Sign C using polyvinylpyrrolidone (PVP), sodium dodecyl sulfonate (SDS), cetyl trimethyl ammonium bromide (CTAB) or tetrapropyl ammonium bromide (TPAB) as surfactant. All the prepared SnO{sub 2} are of a tetragonal crystal structure. Nanocubes, nanorods, nanosheets, nanobelts and nanoparticles were prepared when changing the type and dosage of organic surfactants. It is shown that anionic surfactant (SDS) and cationic surfactant (CTAB or TPAB) at their suitable addition amounts can largely influence the morphologies of SnO{sub 2} nanocrystals. The effect is significantly dependent on the solvent types: water or ethanol. The non-ionic surfactant (PVP) can also change the morphologies like SDS but the impacts are less obvious. The effect of surfactants on the shape and size of SnO{sub 2} nanoparticles was discussed in detail. The particle growth mechanism is described based on the electrostatic interactions and Van der Waals' forces. - Graphical abstract: SnO{sub 2} nanocrystals with controllable morphologies were prepared via a hydrothermal method with surfactants. Highlights: Black-Right-Pointing-Pointer SnO{sub 2} nanocrystals were prepared via a hydrothermal method with surfactants. Black-Right-Pointing-Pointer SnO{sub 2} morphologies changed with the type and the dosage of surfactants. Black-Right-Pointing-Pointer The effect of surfactants on the growth of crystal planes was studied. Black-Right-Pointing-Pointer The controlling mechanisms of surfactants on SnO{sub 2} morphologies were discussed.

  7. Simple Test Functions in Meshless Local Petrov-Galerkin Methods

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.

    2016-01-01

    Two meshless local Petrov-Galerkin (MLPG) methods based on two different trial functions but that use a simple linear test function were developed for beam and column problems. These methods used generalized moving least squares (GMLS) and radial basis (RB) interpolation functions as trial functions. These two methods were tested on various patch test problems. Both methods passed the patch tests successfully. Then the methods were applied to various beam vibration problems and problems involving Euler and Beck's columns. Both methods yielded accurate solutions for all problems studied. The simple linear test function offers considerable savings in computing efforts as the domain integrals involved in the weak form are avoided. The two methods based on this simple linear test function method produced accurate results for frequencies and buckling loads. Of the two methods studied, the method with radial basis trial functions is very attractive as the method is simple, accurate, and robust.

  8. Effects of Mn dope on morphological, structural and optical properties of ZnO nanorods grown by a hydrothermal method

    NASA Astrophysics Data System (ADS)

    Putri, N. A.; Febrianti, Y.; Sugihartono, I.; Fauzia, V.; Handoko, D.

    2017-07-01

    ZnO nanorods were grown on glass substrate has been systematically investigated by varying Mn doping concentrations. The nanorods have been developed by a simple hydrothermal method on the ZnO seed layers which were deposited by ultrasonic spray pyrolysis method. The influences of Mn on the morphological, structural and optical behavior were observed by measuring Scanning Electron Microscope, X-Ray Diffraction, and UV-Vis spectrophotometer, respectively. It is found that the nanorods growth without any orientation. Interestingly, all the nanorods under investigated exhibit a polycrystalline hexagonal wurtzite structure with strong absorption in UV region and a high transparency in the visible region suggesting that optical properties of ZnO nanorods have been modified by Mn doping.

  9. Hydrothermal growth and characterization of vertically well-aligned and dense ZnO nanorods on glass and silicon using a simple optimizer system

    SciTech Connect

    Mohammad, Sabah M. Ahmed, Naser M.; Abd-Alghafour, Nabeel M.; Hassan, Z.; Talib, Rawnaq A.; Omar, A. F.

    2016-07-06

    Vertically, well-aligned and high density ZnO nanorods were successfully hydrothermally grown on glass and silicon substrates using a simple and low cost system. The mechanism of synthesis of ZnO nanorods, generated with our system under hydrothermal conditions, is investigated in this report. Field-emission scanning electron microscopy indicated that the fabricated ZnO nanorods on both substrates have hexagonal shape with diameters ranging from 20 nm to 70 nm which grew vertically from the substrate. XRD analysis confirms the formation of wurtzite ZnO phase with a preferred orientation along (002) direction perpendicular on the substrate and enhanced crystallinity. The low value of the tensile strain (0.126 %) revealed that ZnO nanorods preferred to grow along the c-axis for both substrates. Photoluminescence spectra exhibited a strong, sharp UV near band edge emission peak with narrow FWHM values for both samples.

  10. Synthesis and electrochemical properties of Co3O4 nanoparticles by hydrothermal method at different temperatures

    NASA Astrophysics Data System (ADS)

    Duan, Qiuyan; Chen, Haiyan

    2017-06-01

    In this work, Co3O4 nanoparticles were synthesized by hydrothermal method at different temperatures. The synthesized Co3O4 nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS) and nitrogen adsorption-desorption. The Co3O4 nanoparticles prepared at the hydrothermal temperature of 140 °C and at the annealing temperature of 350 °C have a shorter crystal spacing distance associated to the (220) crystal planes, larger BET surface area and more bivalent cobalt on the surface than these of Co3O4 nanoparticles prepared at higher hydrothermal temperature or higher annealing temperature. The supercapacitor performances of synthesized Co3O4 nanoparticles were analysed by cyclic voltammograms (CVs), Galvano static charge/discharge (GCD) and the electrochemical impedance spectroscopy (EIS) in 6 M KOH aqueous electrolyte solution. The Co3O4 nanoparticles produced at lower temperatures exhibit good pseudo capacitance behaviour. Also, owning to the low hydrothermal temperature and the annealing temperature of Co3O4 nanoparticles, they can be relatively low cost in favour of a promising candidate for electrochemical supercapacitors.

  11. Synthesis of magnetite octahedrons from iron powders through a mild hydrothermal method

    SciTech Connect

    Mao Baodong; Kang Zhenhui; Wang Enbo . E-mail: wangenbo@public.cc.jl.cn; Lian Suoyuan; Gao Lei; Tian Chungui; Wang Chunlei

    2006-12-14

    Magnetite (Fe{sub 3}O{sub 4}) octahedral particles were fabricated from iron powders through a simple one-step alkali-assisted hydrothermal process. The crystallinity, morphology, and structural features of the as-prepared magnetite particles were investigated using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The values of saturation magnetization (M {sub s}) and coercivity (H) of the magnetite octahedrons characterized on a vibrating sample magnetometer (VSM) are 89.81 emu/g and 70.6 Oe, respectively. The concentration of NaOH and the reaction temperature played a key role in the formation of the magnetite octahedrons.

  12. Simple rapid method for gene transfer

    SciTech Connect

    Cockburn, A.F.; Meier, H.

    1990-01-30

    The object of the present invention is to provide methods for gene transfer that reduce or eliminate cellular pretreatment steps, e.g., the removal of cell wall by chemical or enzymatic methods, is rapid and can be practiced without the need of additional expensive equipment. Cells, embryos or tissues selected for genetic manipulation are suspended in an Eppendorf tube in an aliquot of the desired genetic material to be transferred to which the resulting mixture is added and is agitated by vortexing from about 30 to about 90 seconds. The cells, embryos or tissue are sedimented and the DNA supernatant removed. After sedimentation, the injected material is resuspended in or on a growth medium to assay for expression.

  13. Synthesis of SnO 2 micro-spheres, nano-rods and nano-flowers via simple hydrothermal route

    NASA Astrophysics Data System (ADS)

    Vuong, Dang Duc; Hien, Vu Xuan; Trung, Khuc Quang; Chien, Nguyen Duc

    2011-11-01

    SnO 2 micro-spheres (0.5-2 μm diameter), nano-flowers (petal size: 100-250 nm diameter; 500 nm-2 μm length) and nano-rods (3-6 nm diameter; 10-30 nm length) were synthesized by hydrothermal route. The samples were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The influence of precursor, hydrothermal temperature and treatment time on the formation of SnO 2 multi-morphology was also investigated. Moreover, a possible formation mechanism and relationships among morphologies were discussed.

  14. A simple method to estimate interwell autocorrelation

    SciTech Connect

    Pizarro, J.O.S.; Lake, L.W.

    1997-08-01

    The estimation of autocorrelation in the lateral or interwell direction is important when performing reservoir characterization studies using stochastic modeling. This paper presents a new method to estimate the interwell autocorrelation based on parameters, such as the vertical range and the variance, that can be estimated with commonly available data. We used synthetic fields that were generated from stochastic simulations to provide data to construct the estimation charts. These charts relate the ratio of areal to vertical variance and the autocorrelation range (expressed variously) in two directions. Three different semivariogram models were considered: spherical, exponential and truncated fractal. The overall procedure is demonstrated using field data. We find that the approach gives the most self-consistent results when it is applied to previously identified facies. Moreover, the autocorrelation trends follow the depositional pattern of the reservoir, which gives confidence in the validity of the approach.

  15. The simple hydrothermal synthesis of Ag-ZnO-SnO2 nanochain and its multiple applications.

    PubMed

    Balachandran, Subramanian; Selvam, Kaliyamoorthy; Babu, Balraj; Swaminathan, Meenakshisundaram

    2013-12-14

    In this article, we report the fabrication of a stable Ag-ZnO-SnO2 nanochain by template free hydrothermal method and its photocatalytic activity for the first time. This composite material represents a potential new class of photocatalysts with enhanced light absorption, hydrophobic and electronic properties of ZnO. This catalyst has been characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), field emission scanning electron microscopy (FESEM), elemental mapping, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). XRD and elemental mapping reveal the presence of SnO2 and Ag in the catalyst. Ag-ZnO-SnO2 has increased absorption in the visible region when compared to ZnO. This three component nano junction system exhibits enhanced photocatalytic activity for the degradation of azo dyes, Acid Black 1 (AB 1) and Acid Violet 7 (AV 7) under UV light (365 nm), far exceeding those of the single and two component systems. Ag-ZnO-SnO2 is found to be reusable without appreciable loss of catalytic activity up to four runs. Based on the band gap energies of ZnO and SnO2, a mechanism is proposed for the photodegradation of dyes. Hydrophobicity and photoconductivity of Ag-ZnO-SnO2 have been evaluated. Nanochain exhibiting higher positive photoconductivity can be useful for soliton wave communication as well as solar cell applications. Our results provide some new insights on the fabrication of Ag-ZnO-SnO2 and its performance as an active photocatalyst, self cleaning and conducting material.

  16. Simple Weighting Methods to Combine Multimodel Projections

    NASA Astrophysics Data System (ADS)

    Lorenz, R.; Sedlacek, J.; Knutti, R.

    2016-12-01

    Multimodel ensembles of global climate models are very heterogeneous and some models perform better than others for a certain purpose. Nevertheless, weighting of models is rarely performed and there is a debate about whether and how to weight model projections when combining simulations. We argue that the growing number of models with different characteristics and considerable interdependence, at least for cases where relevant metrics of model performance are clear, requires to make use of model constraints to decrease uncertainties in model projections. Steps towards this should involve a) showing unweighted results along with weighted ones, b) testing the robustness of the results towards different metrics or constraints to maximize transparency and comparability across studies, c) an explicit discussion of the choice of metrics, including the physical reasoning why those quantities matter, d) an assessment of the uncertainties in observations, e) testing the sensitivity towards different datasets, time periods, seasonal vs. annual mean values, grid point vs. spatially aggregated data, etc., and f) exploring whether the choice of metric may lead to overconfident results. Several prerequisites need to be met for such approaches to work. For instance, we need available observations, a certain degree of model skill as well as observable relationships that relate to the projections in question. Here we explore projections of summer temperature over central North America. Many CMIP5 models show a pronounced bias of summer temperature over central North America in present climate. We investigate possible causes for this bias and possibilities to constrain the CMIP5 ensemble. We will show if and how uncertainties of projections change depending on weighting method, observational dataset and constraint used.

  17. Synthesis of lithium cobalt oxide by single-step soft hydrothermal method

    SciTech Connect

    Kumar Bokinala, Kiran; Pollet, M.; Artemenko, A.; Miclau, M.; Grozescu, I

    2013-02-15

    Lithium cobalt double oxide LiCoO{sub 2} was synthesized at 220 Degree-Sign C by soft hydrothermal method using Co(OH){sub 2} and LiOH as precursors, LiOH/NaOH as mineralizers and H{sub 2}O{sub 2} as oxidant. The soft hydrothermal synthesis method offers the dual advantage of a much lower synthesis time and a higher purity in comparison with other synthesis methods. The compound was identified by X-ray diffraction and its purity was checked by magnetic and electron magnetic resonance measurements. The grain morphology was studied by Scanning Electron Microscopy and an exponential growth of particle size with synthesis time was observed. - Graphical abstract: Concave cuboctohedrons obtained after 60 h reaction time. Highlights: Black-Right-Pointing-Pointer An optimized soft hydrothermal method for a fast synthesis of high purity LiCoO{sub 2} compound is reported. Black-Right-Pointing-Pointer Both lamellar and cuboctahedral particles could be stabilized. Black-Right-Pointing-Pointer Secondary phases content is lower than 0.1%. Black-Right-Pointing-Pointer Close to surface defects were evidenced using EMR.

  18. Gas-sensing enhancement methods for hydrothermal synthesized SnO2 based sensors.

    PubMed

    Zhao, Yalei; Zhang, Wenlong; Yang, Bin; Liu, Jingquan; Chen, Xiang; Wang, Xiaolin; Yang, Chunsheng

    2017-08-16

    The gas sensing enhancement methods for hydrothermal synthesized SnO2-based gas sensors could be performed from three areas: structural improvement, composition optimization and processing improvement, which were aimed to improve the performance of the gas sensors. There was 0-D, 1-D and 3-D structures reported in literatures. Controllable synthesis of different structures was deployed to increase specific surface area. Change of composition would intensively tailor the SnO2 structure, which affected the gas sensing performance. Besides, doping and compounding methods were adopted to promote gas-sensing performance by adjusting surface condition of SnO2 crystal and constructing heterojunction. As for processing area, it was very important to find the optimal reaction time and temperature. In this paper, gas-solid reaction rate constant was proposed to evaluate gas-sensing property and find the excellent hydrothermal synthesized SnO2-based gas sensor at present. © 2017 IOP Publishing Ltd.

  19. Photocatalytic activity of BiFeO{sub 3} nanoparticles synthesized through hydrothermal method

    SciTech Connect

    Dhanalakshmi, Radhalayam; Muneeswaran, M.; Vanga, Pradeep Reddy; Ashok, M.; Giridharan, N. V.

    2015-06-24

    Multiferroic BiFeO{sub 3} (BFO) nanoparticles (Nps) were synthesized using hydrothermal method. From the X-Ray diffraction analysis (XRD), the synthesized Nps were found to having rhombohedral structure with R3c space group confirmed by Rietveld analysis. Fourier transform infrared spectroscopy (FTIR) analysis was carried out to identify the chemical bonds present in the BFO Nps. Photocatalytic properties of synthesized Nps were studied for the degradation of Methylene Blue (MB) dye under visible light of 150W.

  20. Photocatalytic activity of BiFeO3 nanoparticles synthesized through hydrothermal method

    NASA Astrophysics Data System (ADS)

    Dhanalakshmi, Radhalayam; Muneeswaran, M.; Vanga, Pradeep Reddy; Ashok, M.; Giridharan, N. V.

    2015-06-01

    Multiferroic BiFeO3 (BFO) nanoparticles (Nps) were synthesized using hydrothermal method. From the X-Ray diffraction analysis (XRD), the synthesized Nps were found to having rhombohedral structure with R3c space group confirmed by Rietveld analysis. Fourier transform infrared spectroscopy (FTIR) analysis was carried out to identify the chemical bonds present in the BFO Nps. Photocatalytic properties of synthesized Nps were studied for the degradation of Methylene Blue (MB) dye under visible light of 150W.

  1. Y2O3:Eu nanocrystals as biomarkers prepared by a microwave hydrothermal method

    NASA Astrophysics Data System (ADS)

    Kaszewski, Jarosław; Godlewski, Michał M.; Witkowski, Bartłomiej S.; Słońska, Anna; Wolska-Kornio, Ewelina; Wachnicki, Łukasz; Przybylińska, Hanka; Kozankiewicz, Bolesław; Szal, Anna; Domino, Małgorzata A.; Mijowska, Ewa; Godlewski, Marek

    2016-09-01

    Microwave hydrothermal growth of Y2O3 crystallites results in needle-shaped aggregates of μm length. Thermal treatment has little influence on the material microstructure, but significant impact on the nanometric level. Nanoparticles doped with europium show an intense red luminescence, related to the 5D0 → 7F2 transition of Eu3+ ions. The luminescence intensity increases with the calcination temperature and is accompanied by increasing size of Y2O3:Eu crystallites. EPR studies show the absence of Eu2+ related signals in the material. Y2O3:Eu nanoparticles crystallized via a microwave hydrothermal method were employed as luminescent biomarkers in mice. The initial tests confirmed their applicability as biological markers. Persorption of the Y2O3:Eu nanoparticles after IG in the adult mouse duodenum, brain and liver is reported.

  2. Metastable titanium dioxide B-phase nanowire prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Makal, Pronay; Das, Debajyoti

    2017-05-01

    TiO2-Bronze phase nanowires have been synthesized by hydrothermal method. The influence of post hydrothermal annealing temperature on the formation of TiO2-B NWs has been explored. X-ray diffraction results indicate that the TiO2 NWs consist of Bronze phase (B) only. Transmission electron microscope (TEM) images further confirm the formation of TiO2-B nanowire structure oriented towards dominant <001> and <110> directions. The optical study reveals that the absorption edge red shifted towards longer wavelength with increase in annealing temperature. Band gap narrowing enhances absorption of solar spectrum and oriented growth towards dominant <001> and <110> directions. Coupling of intrinsic channels and the preferentially exposed [010] facets introduces open channels in metastable TiO2-B which may enhance photocatalytic activity due to large surface area creating adsorptive and reactive sites to accelerate the reactions.

  3. Preparation and characterization of nanostructured titanate bioceramic coating by anodization-hydrothermal method

    NASA Astrophysics Data System (ADS)

    Liu, Qiannan; Liu, Yong; Lei, Ting; Tan, Yanni; Wu, Hong; Li, Jianbo

    2015-02-01

    In this work, nanostructured titanate coatings were prepared on pure titanium substrate by hydrothermal treatment combined with and without anodic oxidation. The morphology and microstructure of coatings were characterized and the corrosion resistance and bioactivity were studied. The results show that the anodization-hydrothermal method is suitable for the formation of nanostructured titanate coating on Ti in concentrated KOH solution. The coatings are composed of K2Ti6O13 and H2Ti2O5·H2O, and can greatly improve the corrosion resistance of Ti substrate. Moreover, the coatings can induce the formation of new apatite layer after the immersion in simulated body fluid, exhibiting good bioactivity. The anodizaiton treatment can not only accelerate the formation of nanostructures, but also can provide nucleation sites for nanostructured titanates, tailoring the morphology of coating. The titanium substrate with nanostructured titanate coating is expected to have significant applications as biomedical materials.

  4. Controlled growth of well-aligned ZnO nanowire arrays using the improved hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhitao, Han; Sisi, Li; Jinkui, Chu; Yong, Chen

    2013-06-01

    Well-aligned ZnO nanowires were hydrothermally synthesized based on a facile method for preparing the ZnO seed layer which was derived from the combination of a sol—gel process and the spin-coating technique. The effect of the contents of growth solution and the growth duration on the morphology of ZnO nanowires has been investigated. The results indicated that long and vertically aligned ZnO nanowires could be obtained by adjusting the contents of ammonia and polyethyleneimine (PEI) in the growth solution. Under the optimized condition, the length of ZnO nanowires increased fast and almost linearly with the growth duration. After 10 h incubation, ZnO nanowires more than 25 μm in length were obtained. By combining the conventional photolithographic method with this hydrothermal approach, long and well-aligned ZnO nanowire arrays were selectively grown on the substrate. In addition, the bottom fusion at the foot of the nanowires has been obviously improved. The results demonstrated that the improved hydrothermal process is favorable to synthesize long and well-aligned ZnO nanowires, and possesses good process compatibility with the conventional photolithographic technique for preparing ZnO nanowire arrays. So it has great potential in applications such as display and field emission devices.

  5. Fluorescence characteristics of carbon nanoemitters derived from sucrose by green hydrothermal and microwave methods

    NASA Astrophysics Data System (ADS)

    Patidar, Rajesh; Rebary, Babulal; Bhadu, Gopala Ram

    2016-12-01

    In this work, fluorescent carbon nanoparticles (CNPs) were prepared through two green methods i.e. microwave and hydrothermal, using sucrose as carbon precursor. Both of these methods have offered fluorescent CNPs as characterized by TEM, FTIR, zeta potential, absorbance and emission techniques. Excitation dependent emission spectra were exhibited by aqueous dispersion of these CNPs when they were subjected to different excitation wavelengths. The luminous characteristics of CNPs obtained from both of these methods were studied and compared. Their fluorescence stability in water and buffer was monitored for about three months. Influence of pH and various metal ions on emission spectra were investigated.

  6. Hierarchical Na-doped cubic ZrO{sub 2} synthesis by a simple hydrothermal route and its application in biodiesel production

    SciTech Connect

    Lara-García, Hugo A.; Romero-Ibarra, Issis C.; Pfeiffer, Heriberto

    2014-10-15

    Hierarchical growth of cubic ZrO{sub 2} phase was successfully synthesized via a simple hydrothermal process in the presence of different surfactants (cationic, non-ionic and anionic) and sodium hydroxide. The structural and microstructural characterizations of different ZrO{sub 2} powders were performed using various techniques, such as X-ray diffraction, transmission electron microscopy, N{sub 2} adsorption–desorption, scanning electron microscopy and infrared. Results indicated that sodium addition stabilized the cubic ZrO{sub 2} phase by a Na-doping process, independently of the surfactant used. In contrast, microstructural characteristics varied as a function of the surfactant and sodium presence. In addition, water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties were evaluated on ZrO{sub 2} samples. Results evidenced that sample surface reactivity changed as a function of the sodium content. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction using the different synthesized samples, obtaining yields of 93%. - Graphical abstract: Hierarchical growth of cubic Na-ZrO{sub 2} phase was synthesized by hydrothermal processes in the presence of surfactants and sodium. Sodium addition stabilized the cubic phase by a Na-doping process, while the microstructural characteristics varied with surfactants. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction. - Highlights: • Cubic-ZrO{sub 2} phase was synthesized via a simple hydrothermal process. • ZrO{sub 2} structure and microstructures changed as a function of the surfactant. • Cubic-ZrO{sub 2} phase was evaluated on the biodiesel transesterification reaction.

  7. Synthesis of Silver-Strontium Titanate Hybrid Nanoparticles by Sol-Gel-Hydrothermal Method

    PubMed Central

    Ueno, Shintaro; Nakashima, Kouichi; Sakamoto, Yasunao; Wada, Satoshi

    2015-01-01

    Silver (Ag) nanoparticle-loaded strontium titanate (SrTiO3) nanoparticles were attempted to be synthesized by a sol-gel-hydrothermal method. We prepared the titanium oxide precursor gels incorporated with Ag+ and Sr2+ ions with various molar ratios, and they were successfully converted into the Ag-SrTiO3 hybrid nanoparticles by the hydrothermal treatment at 230 °C in strontium hydroxide aqueous solutions. The morphology of the SrTiO3 nanoparticles is dendritic in the presence and absence of Ag+ ions. The precursor gels, which act as the high reactive precursor, give rise to high nucleation and growth rates under the hydrothermal conditions, and the resultant diffusion-limited aggregation phenomena facilitate the dendritic growth of SrTiO3. From the field-emission transmission electron microscope observation of these Ag-SrTiO3 hybrid nanoparticles, the Ag nanoparticles with a size of a few tens of nanometers are distributed without severe agglomeration, owing to the competitive formation reactions of Ag and SrTiO3.

  8. Facile synthesis of air-stable Prussian white microcubes via a hydrothermal method

    SciTech Connect

    Hu, M.; Jiang, J.S.

    2011-05-15

    Research highlights: {yields} We have synthesized Prussian white microcubes in large quantities by a facile hydrothermal method for the first time. {yields} It is the first report about air-stable PW. {yields} The shape of crystals strongly depended on the concentration of K{sub 4}[Fe(CN){sub 6}], the hydrothermal temperature and the reaction duration. {yields} A layer-by-layer growth mechanism was proposed to explain the formation of PW microcubes. -- Abstract: Air-stable Prussian white (PW) microcubes were fabricated by the slow dissociation of K{sub 4}[Fe(CN){sub 6}] under hydrothermal condition without the protection of inert atmosphere. Moessbauer spectra and Fourier transform infrared (FT-IR) spectrum were used to characterize the composition of PW. X-ray diffraction (XRD) identified the obtained PW was monoclinic, and the purity was high. Scanning electron microscopy (SEM) images indicated the cubes were composed by solid cubes and hollow cubes. The shape of crystals strongly depended on the concentration of K{sub 4}[Fe(CN){sub 6}], the hydrothermal temperature as well as the reaction duration. The lower concentration and lower temperature resulted in perfect cubic crystals, while the higher concentration or the higher temperature resulted in irregular cubic crystals. After exposing in air for 2 months, no oxidation of PW occurred. To explain the formation of the PW microcubes, a layer-by-layer growth mechanism was put forward based on the low dissociation rate of K{sub 4}[Fe(CN){sub 6}]. The partially solubility of PW in water caused the formation of hollow cubes.

  9. Simple-MSSM: a simple and efficient method for simultaneous multi-site saturation mutagenesis.

    PubMed

    Cheng, Feng; Xu, Jian-Miao; Xiang, Chao; Liu, Zhi-Qiang; Zhao, Li-Qing; Zheng, Yu-Guo

    2017-04-01

    To develop a practically simple and robust multi-site saturation mutagenesis (MSSM) method that enables simultaneously recombination of amino acid positions for focused mutant library generation. A general restriction enzyme-free and ligase-free MSSM method (Simple-MSSM) based on prolonged overlap extension PCR (POE-PCR) and Simple Cloning techniques. As a proof of principle of Simple-MSSM, the gene of eGFP (enhanced green fluorescent protein) was used as a template gene for simultaneous mutagenesis of five codons. Forty-eight randomly selected clones were sequenced. Sequencing revealed that all the 48 clones showed at least one mutant codon (mutation efficiency = 100%), and 46 out of the 48 clones had mutations at all the five codons. The obtained diversities at these five codons are 27, 24, 26, 26 and 22, respectively, which correspond to 84, 75, 81, 81, 69% of the theoretical diversity offered by NNK-degeneration (32 codons; NNK, K = T or G). The enzyme-free Simple-MSSM method can simultaneously and efficiently saturate five codons within one day, and therefore avoid missing interactions between residues in interacting amino acid networks.

  10. TiO2 Nanowire dye-sensitized solar cells Fabricated by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Xu, Yang; Gu, Haoshuang; Xia, Huating; Hu, Mingzhe

    2011-02-01

    TiO2 nanowire dye-sensitized solar cells were fabricated by using hydrothermal method. The synthesizing of TiO2 nanowire/nanorod arrays directly on FTO substrate would cause a high conducting loss to solar cells. Through la minating a compact layer between FTO substrate and photonic anode layer, the conducting loss could be effectively prevented. Results indicated that using different concentration of titanium tetrabutoxide would affect the photoelectric conversion efficiency and different producing methods of the compact layer also played an important role to the conversion efficiency.

  11. Hydrothermal synthetic strategies of inorganic semiconducting nanostructures.

    PubMed

    Shi, Weidong; Song, Shuyan; Zhang, Hongjie

    2013-07-07

    Because of their unique chemical and physical properties, inorganic semiconducting nanostructures have gradually played a pivotal role in a variety of research fields, including electronics, chemical reactivity, energy conversion, and optics. A major feature of these nanostructures is the quantum confinement effect, which strongly depends on their size, shape, crystal structure and polydispersity. Among all developed synthetic methods, the hydrothermal method based on a water system has attracted more and more attention because of its outstanding advantages, such as high yield, simple manipulation, easy control, uniform products, lower air pollution, low energy consumption and so on. Precise control over the hydrothermal synthetic conditions is a key to the success of the preparation of high-quality inorganic semiconducting nanostructures. In this review, only the representative hydrothermal synthetic strategies of inorganic semiconducting nanostructures are selected and discussed. We will introduce the four types of strategies based on exterior reaction system adjustment, namely organic additive- and template-free hydrothermal synthesis, organic additive-assisted hydrothermal synthesis, template-assisted hydrothermal synthesis and substrate-assisted hydrothermal synthesis. In addition, the two strategies based on exterior reaction environment adjustment, including microwave-assisted and magnetic field-assisted hydrothermal synthesis, will be also described. Finally, we conclude and give the future prospects of this research area.

  12. A simple method for the deposition of nanostructured tellurium synthesized in ammonia solution

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Lazos, C. D.; Solís-Pomar, F.; Meléndrez, M. F.; Espinoza-Rivas, A. M.; Pérez-Guzmán, M. A.; Ortega-Amaya, R.; Ortega-López, M.; Pérez-Tijerina, E.

    2016-10-01

    In this work, we report a highly adherent, and uniform deposition of nanostructured tellurium. The deposition of the nanostructured tellurium was realized by the dripping of a modified solution of NaHTe based on the dissolution of NaBH4 and tellurium powder in an aqueous solution of NH4OH. This method allowed the relatively simple manipulation of tellurium nanostructures under laboratory ambient, without requiring the use of organic stabilizers. Transmission electron microscopy (TEM) was realized on a powder sample obtained by the reaction between H2Te and aqueous solution of NH4OH. TEM analysis indicated that tellurium nanorods and Y-type nanostructures are grown from tellurium nanoparticles, such as in a hydrothermal system. Then, the nanoparticles serve as seeds for the growth of more extended tellurium nanostructures. Electron diffraction and X-ray diffraction analysis showed that depositions have the hexagonal structure of tellurium highly oriented on (101) direction.

  13. Preparation of meta-stable phases of barium titanate by Sol-hydrothermal method

    SciTech Connect

    Selvaraj, Mahalakshmi; Venkatachalapathy, V.; Karazhanov, S.; Pearce, J. M. E-mail: jeyanthinath@yahoo.co.in

    2015-11-15

    Two low-cost chemical methods of sol–gel and the hydrothermal process have been strategically combined to fabricate barium titanate (BaTiO{sub 3}) nanopowders. This method was tested for various synthesis temperatures (100 °C to 250 °C) employing barium dichloride (BaCl{sub 2}) and titanium tetrachloride (TiCl{sub 4}) as precursors and sodium hydroxide (NaOH) as mineralizer for synthesis of BaTiO{sub 3} nanopowders. The as-prepared BaTiO{sub 3} powders were investigated for structural characteristics using x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The overall analysis indicates that the hydrothermal conditions create a gentle environment to promote the formation of crystalline phase directly from amorphous phase at the very low processing temperatures investigated. XRD analysis showed phase transitions from cubic - tetragonal - orthorhombic - rhombohedral with increasing synthesis temperature and calculated grain sizes were 34 – 38 nm (using the Scherrer formula). SEM and TEM analysis verified that the BaTiO{sub 3} nanopowders synthesized by this method were spherical in shape and about 114 - 170 nm in size. The particle distribution in both SEM and TEM shows that as the reaction temperature increases from 100 °C to 250 °C, the particles agglomerate. Selective area electron diffraction (SAED) shows that the particles are crystalline in nature. The study shows that choosing suitable precursor and optimizing pressure and temperature; different meta-stable (ferroelectric) phases of undoped BaTiO{sub 3} nanopowders can be stabilized by the sol-hydrothermal method.

  14. A simple finite element method for the Stokes equations

    DOE PAGES

    Mu, Lin; Ye, Xiu

    2017-03-21

    The goal of this paper is to introduce a simple finite element method to solve the Stokes equations. This method is in primal velocity-pressure formulation and is so simple such that both velocity and pressure are approximated by piecewise constant functions. Implementation issues as well as error analysis are investigated. A basis for a divergence free subspace of the velocity field is constructed so that the original saddle point problem can be reduced to a symmetric and positive definite system with much fewer unknowns. The numerical experiments indicate that the method is accurate.

  15. A Simple Method for Calculating Clebsch-Gordan Coefficients

    ERIC Educational Resources Information Center

    Klink, W. H.; Wickramasekara, S.

    2010-01-01

    This paper presents a simple method for calculating Clebsch-Gordan coefficients for the tensor product of two unitary irreducible representations (UIRs) of the rotation group. The method also works for multiplicity-free irreducible representations appearing in the tensor product of any number of UIRs of the rotation group. The generalization to…

  16. Studies on n-ZnO/p-Si heterojunction fabricated by hydrothermal method

    SciTech Connect

    V, Shrisha B.; Bhat, Shashidhara; Naik, K GopalaKrishna

    2015-06-24

    Pure and Aluminum (Al) doped ZnO nanorods were grown on silicon (Si) substrates by hydrothermal method. The grown samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). FESEM images shows that there is no distinct difference between morphology of Al-doped and undoped nanorods. The pure and Al doped ZnO nanorods were used to fabricate n-ZnO/p-Si p–n heterojunction diodes. Temperature-dependant (313, 473, 523, 573, 623, and 673 K) current voltage (I–V) characteristics for the fabricated diodes are presented in this paper.

  17. Studies on n-ZnO/p-Si heterojunction fabricated by hydrothermal method

    NASA Astrophysics Data System (ADS)

    V, Shrisha B.; Bhat, Shashidhara; Naik, K. GopalaKrishna

    2015-06-01

    Pure and Aluminum (Al) doped ZnO nanorods were grown on silicon (Si) substrates by hydrothermal method. The grown samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). FESEM images shows that there is no distinct difference between morphology of Al-doped and undoped nanorods. The pure and Al doped ZnO nanorods were used to fabricate n-ZnO/p-Si p-n heterojunction diodes. Temperature-dependant (313, 473, 523, 573, 623, and 673 K) current voltage (I-V) characteristics for the fabricated diodes are presented in this paper.

  18. Defects in ZnO nanorods prepared by a hydrothermal method.

    PubMed

    Tam, K H; Cheung, C K; Leung, Y H; Djurisić, A B; Ling, C C; Beling, C D; Fung, S; Kwok, W M; Chan, W K; Phillips, D L; Ding, L; Ge, W K

    2006-10-26

    ZnO nanorod arrays were fabricated using a hydrothermal method. The nanorods were studied by scanning electron microscopy, photoluminescence (PL), time-resolved PL, X-ray photoelectron spectroscopy, and positron annihilation spectroscopy before and after annealing in different environments and at different temperatures. Annealing atmosphere and temperature had significant effects on the PL spectrum, while in all cases the positron diffusion length and PL decay times were increased. We found that, while the defect emission can be significantly reduced by annealing at 200 degrees C, the rods still have large defect concentrations as confirmed by their low positron diffusion length and short PL decay time constants.

  19. Simple method of measuring delay time in manufacturing delay lines

    NASA Astrophysics Data System (ADS)

    Kasahara, Yukio; Mikoda, Masanari

    1982-07-01

    A simple method for measuring delay time in an operational frequency range is required in manufacturing delay lines used for video tape recorders and television receiver sets. This paper describes a simple method of measuring and adjusting the delay time of such delay lines. The delay time is obtained by measuring a phase difference ϑ between the signals at the input and output transducers of the delay line with frequencies under test. The delay time is more precisely obtained by measuring the ϑ at a constant frequency within the bandwidth of the delay line. A delay-time tolerance of a polished glass medium at 3.58 MHz was found to be within 100 ns. The delay time was found to be shortened by 30 ns by attaching the medium on polishing powder and oil. Also shown is a simple method for adjusting the delay time by polishing a delay medium while measuring the phase difference.

  20. Hydrothermal Alteration Mineralogy Characterized Through Multiple Analytical Methods: Implications for Mars

    NASA Astrophysics Data System (ADS)

    Black, S.; Hynek, B. M.; Kierein-Young, K. S.; Avard, G.; Alvarado-Induni, G.

    2015-12-01

    Proper characterization of mineralogy is an essential part of geologic interpretation. This process becomes even more critical when attempting to interpret the history of a region remotely, via satellites and/or landed spacecraft. Orbiters and landed missions to Mars carry with them a wide range of analytical tools to aid in the interpretation of Mars' geologic history. However, many instruments make a single type of measurement (e.g., APXS: elemental chemistry; XRD: mineralogy), and multiple data sets must be utilized to develop a comprehensive understanding of a sample. Hydrothermal alteration products often exist in intimate mixtures, and vary widely across a site due to changing pH, temperature, and fluid/gas chemistries. These characteristics require that we develop a detailed understanding regarding the possible mineral mixtures that may exist, and their detectability in different instrument data sets. This comparative analysis study utilized several analytical methods on existing or planned Mars rovers (XRD Raman, LIBS, Mössbauer, and APXS) combined with additional characterization (thin section, VNIR, XRF, SEM-EMP) to develop a comprehensive suite of data for hydrothermal alteration products collected from Poás and Turrialba volcanoes in Costa Rica. Analyzing the same samples across a wide range of instruments allows for direct comparisons of results, and identification of instrumentation "blind spots." This provides insight into the ability of in-situ analyses to comprehensively characterize sites on Mars exhibiting putative hydrothermal characteristics, such as the silica and sulfate deposits at Gusev crater [eg: Squyres et al., 2008], as well as valuable information for future mission planning and data interpretation. References: Squyres et al. (2008), Detection of Silica-Rich Deposits on Mars, Science, 320, 1063-1067, doi:10.1126/science.1155429.

  1. Synthesis of single-crystal PbS nanorods via a simple hydrothermal process using PEO-PPO-PEO triblock copolymer as a structure-directing agent

    NASA Astrophysics Data System (ADS)

    Bu, Junfu; Nie, Chageng; Liang, Jinxia; Sun, Lan; Xie, Zhaoxiong; Wu, Qi; Lin, Changjian

    2011-03-01

    Single-crystal PbS nanorods were successfully synthesized through a simple hydrothermal route using PEO-PPO-PEO triblock copolymer (P123) as a structure-directing agent. The XRD pattern indicates that the crystal structure of the nanorods is face-centre-cubic rocksalt. A SEM image shows that the nanorods have a diameter of 40-70 nm and a length of 200-600 nm, and both tips exhibit taper-like structures. HRTEM and SAED images reveal the single-crystalline nature of the nanorods with the growth along the lang111rang direction. The experimental results indicated that the P123 concentration and reaction temperature played important roles in controlling the morphology of the PbS nanostructures. The optical property of PbS nanorods was investigated by UV-Vis absorption spectroscopy and the band structure was calculated by the B3LYP hybrid density functional theory.

  2. Hierarchical Na-doped cubic ZrO2 synthesis by a simple hydrothermal route and its application in biodiesel production

    NASA Astrophysics Data System (ADS)

    Lara-García, Hugo A.; Romero-Ibarra, Issis C.; Pfeiffer, Heriberto

    2014-10-01

    Hierarchical growth of cubic ZrO2 phase was successfully synthesized via a simple hydrothermal process in the presence of different surfactants (cationic, non-ionic and anionic) and sodium hydroxide. The structural and microstructural characterizations of different ZrO2 powders were performed using various techniques, such as X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, scanning electron microscopy and infrared. Results indicated that sodium addition stabilized the cubic ZrO2 phase by a Na-doping process, independently of the surfactant used. In contrast, microstructural characteristics varied as a function of the surfactant and sodium presence. In addition, water vapor (H2O) and carbon dioxide (CO2) sorption properties were evaluated on ZrO2 samples. Results evidenced that sample surface reactivity changed as a function of the sodium content. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction using the different synthesized samples, obtaining yields of 93%.

  3. Facile synthesis of graphene/ZnO nanocomposites by low temperature hydrothermal method

    SciTech Connect

    Saravanakumar, Balasubramaniam; Mohan, Rajneesh; Kim, Sang-Jae

    2013-02-15

    Highlights: ► Graphene/ZnO nanocomposites were prepared by low temperature hydrothermal method. ► Rhodamine-B degraded by using graphene/ZnO nanocomposites. ► ZnO anchored well on the surface of graphene. -- Abstract: Graphene/ZnO nanocomposites have been synthesized using hydrothermal method at two different temperatures 80 and 90 °C. The structure, morphology and optical properties of as synthesized nanocomposites were analyzed through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and UV–vis absorbance spectroscopy. The XRD pattern confirmed the formation of graphene decorated by hexagonal ZnO with high crystallinity. FESEM image revealed that the sheet like graphene decorated with ZnO in homogeneously. Decoration of quasi-spherical ZnO nanoparticles on graphene sheet was confirmed by TEM. The characteristic absorbance peaks of graphene/ZnO nanocomposites were observed in UV visible spectra. The photocatalytic degradation experiment was performed against rhodamine-B dye and showed good catalytic activity for both samples. The graphene/ZnO nanocomposites showed higher catalytic activity then ZnO nanoparticles. The GZN-90 sample showed more catalytic activity than GZN-80 due to higher density of ZnO in graphene surface generates large number of photo-induced electron.

  4. Using container weights to determine irrigation needs: A simple method

    Treesearch

    R. Kasten Dumroese; Mark E. Montville; Jeremiah R. Pinto

    2015-01-01

    Proper irrigation can reduce water use, water waste, and incidence of disease. Knowing when to irrigate plants in container nurseries can be determined by weighing containers. This simple method is quantifiable, which is a benefit when more than one worker is responsible for irrigation. Irrigation is necessary when the container weighs some target as a proportion of...

  5. A simple method for the purification of Eimeria tenella sporozoites.

    PubMed

    Mattig, F R; Drössigk, U; Entzeroth, R

    1993-05-01

    A rapid, simple and cheap method for the purification of Eimeria tenella sporozoites has been developed using commercially available filter paper (595 filter paper circles, Schleicher & Schuell, 3354 Dassel, Germany, order 311610). Yield and purity are of the same value as by purification with a leukopac column (Bontemps & Yvore 1974). The described method can be used for the purification of Eimeria tenella sporozoites under sterile conditions for subsequent in vitro cultivation.

  6. Upconversion and downconversion luminescence properties of Er3+ doped NBT ceramics synthesized via hydrothermal method

    NASA Astrophysics Data System (ADS)

    Sun, Jianjian; Fang, Bijun; Zhang, Shuai; Chen, Zhihui; Ding, Jianning; Zhao, Xiangyong; Luo, Haosu

    2017-07-01

    Er3+-doped Na0.5Bi0.5TiO3 (Er-doped NBT) ceramics were prepared via a hydrothermal method. High sintering active Er-doped NBT nano cubic particles with perovskite structure were synthesized at hydrothermal condition of 200 °C for 24 h in 12 M NaOH solution, which were self-assembled via in situ crystallization mechanism by the initially as-grown nanowires. The Er-doped NBT ceramics sintered at 1100 °C for 2 h exhibit pure rhombohedral perovskite structure, high densification and rather homogenous microstructure morphology. Under 488 nm light excitation, the strong green emission peaks centering at 530 nm and 550 nm and the weak red emission peaks locating at 665 nm and 735 nm are excited, which can be attributed to the 2H11/2, 4S3/2, 4F9/2 and 4I9/2 → 4I15/2 transitions, respectively. The maximum emission intensity is obtained when the Er doping content reaches 1.0 mol%. A strong upconversion emission peak centering around 550 nm in green light range is excited under 800 nm light excitation, which is correlated with the 4S3/2 → 4I15/2 transition.

  7. Size effect of Raman scattering on CeO2 nanocrystal by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Hattori, Takashi; Kobayashi, Katsutoshi; Ozawa, Masakuni

    2017-01-01

    In this study, we prepared surface-modified CeO2 nanocrystals (NCs) by a hydrothermal method, and calcined CeO2 NCs at various temperatures between 400 and 1000 °C for 3 h in air to obtain crystal-size-controlled CeO2 NCs. We investigated the correlation between the Raman spectra and the crystal sizes of the CeO2 powder. The peak position of the F2g mode of CeO2 was shifted to lower energies as the crystal size decreased and the peak broadened. The present hydrothermally driven CeO2 NCs showed no change in lattice constant depending on crystal size after heat treatment. The Raman peak position of the F2g mode as a function of inverse CeO2 crystal size corresponded to the models for phonon confinement without the combination of strain and defect effects. Moreover, it was also suggested that the Raman peak width of CeO2 NCs without strain also showed dependence on particle size.

  8. Clustered Simple Cell Mapping: An extension to the Simple Cell Mapping method

    NASA Astrophysics Data System (ADS)

    Gyebrószki, Gergely; Csernák, Gábor

    2017-01-01

    When a dynamical system has a complex structure of fixed points, periodic cycles or even chaotic attractors, Cell Mapping methods are excellent tools to discover and thoroughly analyse all features in the state space. These methods discretize a region of the state space into cells and examine the dynamics in the cell state space. By determining one or more image cells for each cell, the global behaviour within the region can be quickly determined. In the simplest case - Simple Cell Mapping (SCM) method - only one image corresponds to a cell and usually a rectangular grid of cells is used. In typical applications the grid of cells is refined at specific locations. This paper, however, introduces a different approach, which is useful to expand the analysed state space region to include all features which properly characterize the global dynamics of the system. Instead of refining the initial cell state space, we start with a small initial state space region, analyse other interesting regions of the state space and incorporate them into a cluster of cell mapping solutions. By this approach, trajectories escaping the original state space region can be followed automatically and additional objects in the state space can be discovered. To illustrate the benefits of the method, we present the exploration of the phase-space of the micro-chaos map - a simple model of digitally controlled systems.

  9. Simple Moving Average: A Method of Reporting Evolving Complication Rates.

    PubMed

    Harmsen, Samuel M; Chang, Yu-Hui H; Hattrup, Steven J

    2016-09-01

    Surgeons often cite published complication rates when discussing surgery with patients. However, these rates may not truly represent current results or an individual surgeon's experience with a given procedure. This study proposes a novel method to more accurately report current complication trends that may better represent the patient's potential experience: simple moving average. Reverse shoulder arthroplasty (RSA) is an increasingly popular and rapidly evolving procedure with highly variable reported complication rates. The authors used an RSA model to test and evaluate the usefulness of simple moving average. This study reviewed 297 consecutive RSA procedures performed by a single surgeon and noted complications in 50 patients (16.8%). Simple moving average for total complications as well as minor, major, acute, and chronic complications was then calculated using various lag intervals. These findings showed trends toward fewer total, major, and chronic complications over time, and these trends were represented best with a lag of 75 patients. Average follow-up within this lag was 26.2 months. Rates for total complications decreased from 17.3% to 8% at the most recent simple moving average. The authors' traditional complication rate with RSA (16.8%) is consistent with reported rates. However, the use of simple moving average shows that this complication rate decreased over time, with current trends (8%) markedly lower, giving the senior author a more accurate picture of his evolving complication trends with RSA. Compared with traditional methods, simple moving average can be used to better reflect current trends in complication rates associated with a surgical procedure and may better represent the patient's potential experience. [Orthopedics.2016; 39(5):e869-e876.].

  10. A simple three dimensional wide-angle beam propagation method

    NASA Astrophysics Data System (ADS)

    Ma, Changbao; van Keuren, Edward

    2006-05-01

    The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra’s scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

  11. Ion substitutions and non-stoichiometry of carbonated apatite-(CaOH) synthesised by precipitation and hydrothermal methods

    NASA Astrophysics Data System (ADS)

    Frank-Kamenetskaya, Olga; Kol'tsov, Alexander; Kuz'mina, Maria; Zorina, Maina; Poritskaya, Lilya

    2011-04-01

    Apatite-(CaOH), either carbonate-free or with different concentrations of carbonate ions of the predominantly (not less than 60%) B type, was synthesised by precipitation from solutions, by hydrothermal methods from solid compounds and by hydrothermal treatment of calcite. In B type apatite, the concentration of CO32- ions could be up to 20.5 wt.%. The reverse precipitation method and hydrothermal treatment of calcite obtained monophase samples with a maximal concentration of CO32- ions of 10.3-10.5 wt.%. In apatites of a mixed type, the total concentration of CO32- ions did not exceed 8 wt.%. The synthesised apatites could be divided into three groups according to the degree and origin of non-stoichiometry: Apatite of nearly stoichiometric composition. Apatite of this type was synthesised by all methods. Calcium-deficient apatite. The Ca deficit was mainly due to CO32- incorporation. Monophase samples with maximal concentrations of CO32- ions were synthesised by the reverse precipitation method and by hydrothermal treatment of calcite. Calcium-deficient apatite. The Ca deficit was mainly due to a deficit of OH - ions and resulted in the incorporation of water into channels of the crystal structure. This group was synthesised by reverse precipitation and hydrothermal methods. This apatite was a crystal chemical analogue of the apatite formed in the hard tissues of the human body such as teeth, bone and different stones. Apatites formed by the precipitation methods revealed higher variations in composition (including variations in the concentration of CO32- ions), compared to hydrothermally-synthesised samples. The observed effect of aqueous solution composition on the ion substitution and apatite composition was stronger than previously reported.

  12. Structural phase transformations in KYF4:Er3+ nanoparticles synthesized by hydrothermal method for upconversion applications

    NASA Astrophysics Data System (ADS)

    Yamini, S.; Priya, P. Sakthi; Gunaseelan, M.; Senthilselvan, J.

    2017-05-01

    KYF4:10%Er3+ upconversion nanoparticles was synthesized by hydrothermal method with potassium hydroxides (KOH) as precursor. Prepared samples were calcined at 600 °C using double crucible method. XRD patterns of as prepared KYF4 and KYF4:Er3+ samples confirm the tetragonal structure, which is well matched with the standard data. Surface morphology is recorded for 600 °C calcined samples using High resolution scanning electron microscopy (HRSEM) shows spheroidal shape with particle sizes of ˜80 nm. From UV-Visible and EDX spectroscopy presence of Er3+ in KYF4:10%Er3+ is confirmed. The prepared KYF4:10%Er3+ can be used to improve efficiency of solar cells, display devices and fiber optical telecommunication applications.

  13. Synthesis and characterization of WO{sub 3} nanostructures prepared by an aged-hydrothermal method

    SciTech Connect

    Huirache-Acuna, R.; Paraguay-Delgado, F.; Albiter, M.A.; Lara-Romero, J.; Martinez-Sanchez, R.

    2009-09-15

    Nanostructures of tungsten trioxide (WO{sub 3}) have been successfully synthesized by using an aged route at low temperature (60 deg. C) followed by a hydrothermal method at 200 deg. C for 48 h under well controlled conditions. The material was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Specific Surface Area (S{sub BET}) were measured by using the BET method. The lengths of the WO{sub 3} nanostructures obtained are between 30 and 200 nm and their diameters are from 20 to 70 nm. The growth direction of the tungsten oxide nanostructures was determined along [010] axis with an inter-planar distance of 0.38 nm.

  14. Synthesis of polyethylenimine (PEI) functionalized silver nanoparticles by a hydrothermal method and their antibacterial activity study.

    PubMed

    Liu, Zhiguo; Wang, Yuanlin; Zu, Yuangang; Fu, Yujie; Li, Na; Guo, Na; Liu, Ruisi; Zhang, Yiming

    2014-09-01

    In this study, we report a facile, one-step hydrothermal method to synthesize PEI-functionalized Ag nanoparticles in which no extra reducing agent is needed and PEI serves as a reducing agent and a stabilizing agent. The obtained Ag colloids have been characterized by TEM, UV absorption spectra and laser particle size analyzer. We found that the size of Ag nanoparticles can be tuned through the alteration of the temperature and growth mode. Under an acidic condition, PEI-functionalized Ag nanoparticles are positively charged. More importantly, the Ag colloids exhibited stronger antibacterial activity in the bactericidal test. Its bactericidal efficiency exceeds the commonly used antibacterial agents such as Erythromycin, chloramphenicol and penicillin as well as AgNO3 solution. These results prove that our synthesis method is very efficient to produce a stable PEI-functionalized Ag colloid with excellent antibacterial activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Controllable preparation of flower-like brookite TiO{sub 2} nanostructures via one-step hydrothermal method

    SciTech Connect

    Zou, Yunling; Tan, Xin; Yu, Tao; Li, Yan; Li, Yimei; Wang, Ru; Xue, Lingqian

    2016-08-15

    Highlights: • Flower-like brookite TiO{sub 2} structures were prepared by hydrothermal method. • PVP not only acted as a dispersant but also stabilized the layered structure. • The resulted brookite TiO{sub 2} showed high photocatalytic activity under UV irradiation. - Abstract: Flower-like brookite TiO{sub 2} nanostructures were controllable prepared by a one-step hydrothermal method by changing experimental conditions, such as hydrothermal temperature, reaction time and the amount of polyvinylpyrrolidone. The photocatalytic activities of the samples were investigated by degradation of methylene blue (MB) in aqueous solution under UV light irradiation. It was found that the formation of brookite TiO{sub 2} nanostructures with various morphologies could be well controlled by the adjustment of hydrothermal temperature, reaction time and the amount of surfactant, and the morphology of the products changed from spindle-like structures to flower-like structures with the increase of hydrothermal temperature, reaction time and the amount of surfactant. The photocatalytic tests indicate that the flower-like brookite TiO{sub 2} nanostructures shows high photocatalytic activity in degradation of methylene blue (MB) under UV light irradiation. The formation mechanism of flower-like brookite TiO{sub 2} nanostructures was also discussed in detail based on the above investigations.

  16. A simple method for HbF analysis.

    PubMed

    von Mandach, U; Tuchschmid, P; Huch, A; Huch, R

    1987-01-01

    Spectrophotometric methods with CO-oxymeters for measurements of carboxyhemoglobin and/or oxygen saturation in human blood include a systematic error depending on the percentage of fetal hemoglobin. It is of clinical importance to estimate the fetal hemoglobin to correct HbCO and SO2 values respectively. The described method is simple and less time consuming than conventional methods like HPLC or electrophoresis. The two measurements of oxy- and carboxyhemoglobin in the same blood sample with different oxygen saturation are needed for the estimation of the HbF and can be performed, including the deoxygenation procedure, in about 40 minutes.

  17. A simple and inexpensive method for muddy shore profiling

    NASA Astrophysics Data System (ADS)

    Chowdhury, Sayedur Rahman; Hossain, M. Shahadat; Sharifuzzaman, S. M.

    2014-11-01

    There are several well-established methods for obtaining beach profiles, and more accurate and precise high-tech methods are emerging. Traditional low-cost methods requiring minimal user skill or training are still popular among professionals, scientists, and coastal zone management practitioners. Simple methods are being developed with a primary focus on sand and gravel beaches. This paper describes a simple, low-cost, manual field method for measuring profiles of beaches, which is particularly suitable for muddy shores. The equipment is a type of flexible U-tube manometer that uses liquid columns in vertical tubes to measure differences in elevation; the supporting frame is constructed from wooden poles with base disks, which hold measuring scales and a PVC tube. The structure was trialed on a mudflat characterized by a 20-40-cm-thick surface layer of silt and clay, located at the Kutubdia Island, Bangladesh. The study results are discussed with notes on the method's applicability, advantages and limitations, and several optional modifications for different scenarios for routine profiling of muddy shores. The equipment can be used by one person or two people, and the accuracy of the method is comparable to those in other methods. The equipment can also be used on sandy or gravel beaches.

  18. Simple noise-reduction method based on nonlinear forecasting.

    PubMed

    Tan, James P L

    2017-03-01

    Nonparametric detrending or noise reduction methods are often employed to separate trends from noisy time series when no satisfactory models exist to fit the data. However, conventional noise reduction methods depend on subjective choices of smoothing parameters. Here we present a simple multivariate noise reduction method based on available nonlinear forecasting techniques. These are in turn based on state-space reconstruction for which a strong theoretical justification exists for their use in nonparametric forecasting. The noise reduction method presented here is conceptually similar to Schreiber's noise reduction method using state-space reconstruction. However, we show that Schreiber's method has a minor flaw that can be overcome with forecasting. Furthermore, our method contains a simple but nontrivial extension to multivariate time series. We apply the method to multivariate time series generated from the Van der Pol oscillator, the Lorenz equations, the Hindmarsh-Rose model of neuronal spiking activity, and to two other univariate real-world data sets. It is demonstrated that noise reduction heuristics can be objectively optimized with in-sample forecasting errors that correlate well with actual noise reduction errors.

  19. Simple noise-reduction method based on nonlinear forecasting

    NASA Astrophysics Data System (ADS)

    Tan, James P. L.

    2017-03-01

    Nonparametric detrending or noise reduction methods are often employed to separate trends from noisy time series when no satisfactory models exist to fit the data. However, conventional noise reduction methods depend on subjective choices of smoothing parameters. Here we present a simple multivariate noise reduction method based on available nonlinear forecasting techniques. These are in turn based on state-space reconstruction for which a strong theoretical justification exists for their use in nonparametric forecasting. The noise reduction method presented here is conceptually similar to Schreiber's noise reduction method using state-space reconstruction. However, we show that Schreiber's method has a minor flaw that can be overcome with forecasting. Furthermore, our method contains a simple but nontrivial extension to multivariate time series. We apply the method to multivariate time series generated from the Van der Pol oscillator, the Lorenz equations, the Hindmarsh-Rose model of neuronal spiking activity, and to two other univariate real-world data sets. It is demonstrated that noise reduction heuristics can be objectively optimized with in-sample forecasting errors that correlate well with actual noise reduction errors.

  20. SIMPLE: a sequential immunoperoxidase labeling and erasing method.

    PubMed

    Glass, George; Papin, Jason A; Mandell, James W

    2009-10-01

    The ability to simultaneously visualize expression of multiple antigens in cells and tissues can provide powerful insights into cellular and organismal biology. However, standard methods are limited to the use of just two or three simultaneous probes and have not been widely adopted for routine use in paraffin-embedded tissue. We have developed a novel approach called sequential immunoperoxidase labeling and erasing (SIMPLE) that enables the simultaneous visualization of at least five markers within a single tissue section. Utilizing the alcohol-soluble peroxidase substrate 3-amino-9-ethylcarbazole, combined with a rapid non-destructive method for antibody-antigen dissociation, we demonstrate the ability to erase the results of a single immunohistochemical stain while preserving tissue antigenicity for repeated rounds of labeling. SIMPLE is greatly facilitated by the use of a whole-slide scanner, which can capture the results of each sequential stain without any information loss.

  1. Simple methods for characterization of metals in historical textile threads.

    PubMed

    Rezić, Iva; Curković, Lidija; Ujević, Magdalena

    2010-06-30

    Characterization of metal threads on historical textile materials is important for preservation of valuable cultural heritage. Obtained results dictate decisions on cleaning, conservation and restoration steps. The most important part of characterization is chemical analysis of originally applied materials, since this enables understanding the nature of chemical and physical degradation and determines the cleaning methods. Methods applied should be non-destructive and sensitive enough to detect trace elements in small sample amounts. The goal of this research was to describe the most useful procedures for fast and simple determination of specific metals of interest. Therefore we propose application of scanning electron microscopy equipped with EDS detector (SEM-EDS) for sample surface analysis and inductively coupled plasma-optical emission spectroscopy (ICP-OES) for chemical analysis of metals threads. For quality insurance reasons, a comparative method applied for chemical analysis was atomic absorption spectrometry (AAS). This combination of methods has proven to be very useful in analysis of historical samples, since SEM-EDS was a simple and non-destructive method which provided information on chemical composition of sample surfaces, while ICP-OES and AAS enabled the full insight into the average chemical composition of samples. Nevertheless, both ICP-OES and AAS were destructive methods which demanded dissolving of samples prior to the analysis. In this work nine different metal fibers collected from historical textile materials were characterized. Proposed methods enabled obtaining information on sample constitution, morphology, topology and chemical composition. Copyright 2010 Elsevier B.V. All rights reserved.

  2. A comparison of simple shear characterization methods for composite laminates

    NASA Technical Reports Server (NTRS)

    Yeow, Y. T.; Brinson, H. F.

    1977-01-01

    Various methods for the shear stress-strain characterization of composite laminates are examined, and their advantages and limitations are briefly discussed. Experimental results and the necessary accompanying analysis are then presented and compared for three simple shear characterization procedures. These are the off-axis tensile test method, the + or - 45 degs tensile test method and the 0 deg/90 degs symmetric rail shear test method. It is shown that the first technique indicates that the shear properties of the G/E laminates investigated are fundamentally brittle in nature while the latter two methods tend to indicate that the G/E laminates are fundamentally ductile in nature. Finally, predictions of incrementally determined tensile stress-strain curves utilizing the various different shear behavior methods as input information are presented and discussed.

  3. Simple method for quick estimation of aquifer hydrogeological parameters

    NASA Astrophysics Data System (ADS)

    Ma, C.; Li, Y. Y.

    2017-08-01

    Development of simple and accurate methods to determine the aquifer hydrogeological parameters was of importance for groundwater resources assessment and management. Aiming at the present issue of estimating aquifer parameters based on some data of the unsteady pumping test, a fitting function of Theis well function was proposed using fitting optimization method and then a unitary linear regression equation was established. The aquifer parameters could be obtained by solving coefficients of the regression equation. The application of the proposed method was illustrated, using two published data sets. By the error statistics and analysis on the pumping drawdown, it showed that the method proposed in this paper yielded quick and accurate estimates of the aquifer parameters. The proposed method could reliably identify the aquifer parameters from long distance observed drawdowns and early drawdowns. It was hoped that the proposed method in this paper would be helpful for practicing hydrogeologists and hydrologists.

  4. Temperature dependent morphology variation of red emitting microcrystalline YPO4:Eu3+ fabricated by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Cybińska, Joanna

    2017-03-01

    Phosphor materials based on the orthophosphates have been widely investigated in the past as crystals, bulk, or nanomaterials. These non-hydroscopic matrices are able to accommodate high concentrations of lanthanide ions without suffering of concentration quenching of the luminescence. One of the most important issue, which is necessary to overcome to use these materials as a phosphors it is to find a synthesis route giving a control over the products morphology, what allows to manage their spectroscopic properties. The investigated YPO4:Eu3+ samples doped with 5 mol % of optically active ions were prepared by the classic hydrothermal method. By changing the temperature of the synthesis it is possible to control the shape and the size of the particles. Based on the results obtained from the electron microscopy studies (TEM and SEM) the morphology of the obtained materials has been correlated with their optical properties such as decay times or emission quantum yields.

  5. Improved dye-sensitized solar cell with a ZnO nanotree photoanode by hydrothermal method.

    PubMed

    Kuo, Shou-Yi; Yang, Jui-Fu; Lai, Fang-I

    2014-01-01

    This study investigated the influence of ZnO nanostructures on dye adsorption to increase the photovoltaic conversion efficiency of solar cells. ZnO nanostructures were grown in both tree-like and nanorod (NR) arrays on an AZO/FTO film structure by using a hydrothermal method. The results were observed in detail using X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), UV-visible spectrophotometry, electrochemical impedance spectroscopy, and solar simulation. The selective growth of tree-like ZnO was found to exhibit higher dye adsorption loading and conversion efficiency than ZnO NRs. The multiple 'branches' of 'tree-like nanostructures' increases the surface area for higher light harvesting and dye loading while reducing charge recombination. These improvements result in a 15% enhancement in power conversion. The objective of this study is to facilitate the development of a ZnO-based dye-sensitized solar cell.

  6. Sintering Behavior of Magnesium-Substituted Fluorapatite Powders Prepared by Hydrothermal Method

    PubMed Central

    Nasr, S.; Bouzouita, K.

    2011-01-01

    Magnesium-substituted fluorapatite powders were synthesized by hydrothermal method, and their sintering behavior was investigated by dilatometry in the temperature range 25–1100°C. Analysis of the obtained powders by X-ray diffraction and 31P NMR spectroscopy showed that the powders consisted of a single apatite phase and no amorphous phase has been formed. Compared to pure fluorapatite, the shrinkage of the substituted samples occurred in two steps and the temperature at which the sintering rate was maximum is lower. In addition, the shrinkage was interrupted by an expansion of the samples due to the formation of a liquid phase. The latter phase led to the crystallization of needle-crystals by a dissolution-diffusion-reprecipitation process. PMID:21577315

  7. Growth of freestanding lead dual-halide thin film and microbulk via hydrothermal method

    NASA Astrophysics Data System (ADS)

    Fang, Die; Wangyang, Peihua; Sun, Hui; Yang, Dingyu; Gao, Xiuying; Tian, Haibo; Zhu, Xinghua

    2017-03-01

    In this paper, we report a facile growth of freestanding PbI2‑x Cl x film and microbulk via hydrothermal method without additives. The properties of samples were systematically investigated by field emission scanning electron microscopy, x-ray diffraction and UV–vis diffuse reflection spectroscopy. The results reveal that there appears to be two types of morphological PbI2‑x Cl x due to the anisotropy in the effective surface energy, and the underlying growth mechanism behind the observation is also discussed. This new approach is promising for the fabrication of PbI2‑x Cl x precursor material of detectors and solar cells.

  8. Thermoelectric Properties of Bi2Te3 Nanocrystals with Diverse Morphologies Obtained via Modified Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Dharmaiah, Peyala; Hong, Soon-Jik

    2016-11-01

    Single-phase Bi2Te3 nanostructures (spherical and flower-like) have been synthesized using a modified hydrothermal method at different reaction temperatures (70°C, 100°C, and 150°C) and subsequently consolidated by spark plasma sintering. Their crystal structure, morphology, and thermoelectric and mechanical properties were investigated. The results suggest that the reaction temperature had a significant effect on the morphology and thermoelectric properties. The presence of nanostructures in bulk samples led to a remarkable decrease in thermal conductivity with a lesser effect on electrical conductivity. As a result, the figure of merit (ZT) of the spark-plasma-sintered sample processed from spherical nanoparticles reached 0.54 at 400 K. The Vickers microhardness of the bulk sample processed from spherical nanoparticles was higher than the best results found in literature.

  9. Influence of Heat Treatment on Photocatalytic Performance of BiVO4 Synthesized by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Shen, Yi; Wang, Xiaomin; Zuo, Guifu; Li, Fengfeng; Meng, Yanzhi

    2016-10-01

    Monoclinic BiVO4 photocatalyst was successfully synthesized by hydrothermal method under appropriate temperature. The photocatalytic performance of BiVO4 was improved by calcining at appropriate temperature. The structural and morphological properties of the synthesized BiVO4 photocatalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It is confirmed that the photocatalytic activity of the prepared catalysts was evaluated by the photodegradation of RhB under visible-light irradiation. BiVO4 calcined under appropriate temperature exhibited higher photocatalytic activity than uncalcined BiVO4 under visible light irradiation because calcination might effectively increases the purity of monoclinic bismuth vanadate.

  10. Thermoelectric Properties of Bi2Te3 Nanocrystals with Diverse Morphologies Obtained via Modified Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Dharmaiah, Peyala; Hong, Soon-Jik

    2017-05-01

    Single-phase Bi2Te3 nanostructures (spherical and flower-like) have been synthesized using a modified hydrothermal method at different reaction temperatures (70°C, 100°C, and 150°C) and subsequently consolidated by spark plasma sintering. Their crystal structure, morphology, and thermoelectric and mechanical properties were investigated. The results suggest that the reaction temperature had a significant effect on the morphology and thermoelectric properties. The presence of nanostructures in bulk samples led to a remarkable decrease in thermal conductivity with a lesser effect on electrical conductivity. As a result, the figure of merit ( ZT) of the spark-plasma-sintered sample processed from spherical nanoparticles reached 0.54 at 400 K. The Vickers microhardness of the bulk sample processed from spherical nanoparticles was higher than the best results found in literature.

  11. Ultraviolet Photoconductive Detectors Based on A-Plane ZnO Film Grow by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Yu, Naisen; Dong, Dapeng; Qi, Yan; Wu, Yunfeng; Chen, Lu

    2016-02-01

    A-plane ZnO film was grown on a-plane GaN/r-sapphire template by using the hydrothermal growth method. The film was characterized for the structural and morphological properties by means of x-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results show the a-plane ZnO film with a very uniform striated morphology was achieved. Meanwhile, an ultraviolet (UV) photoconductive detector based on the as-grown a-plane film was fabricated, and the detector current was increased by more than 17 times under 5 V bias upon UV illumination. Moreover, it also showed good reproducibility and stability, which confirms the film as a good potential material for UV optoelectronic devices.

  12. Synthesize and characterization of nanostructure magnetic cobalt ferrite using hydrothermal method

    NASA Astrophysics Data System (ADS)

    Moosavi, Seyedehmaryam; Zakaria, Sarani; Chia, Chin Hua; Gan, Sinyee

    2016-11-01

    In this paper a series of nanostructured magnetic cobalt ferrite were synthesized by hydrothermal method using stable ferric and cobalt salts with sodium hydroxide as the surfactant. X-ray Diffraction (XRD) and field-emission scanning electron microscopy (FESEM) were employed to evaluate the structural properties of synthesized nanoparticles. X-ray diffraction analysis confirmed that the cobalt ferrite nanoparticles had a single-phase spinel structure. From the analysis of the powder X-ray diffraction patterns, the average crystallite size was calculated using the Scherrer formula. The results showed that the average crystallite size is in the range of 63-74 nm increases, depending on the annealing temperature and time.

  13. Synthesis of high saturation magnetic iron oxide nanomaterials via low temperature hydrothermal method

    NASA Astrophysics Data System (ADS)

    Bhavani, P.; Rajababu, C. H.; Arif, M. D.; Reddy, I. Venkata Subba; Reddy, N. Ramamanohar

    2017-03-01

    Iron oxide nanoparticles (IONPs) were synthesized through a simple low temperature hydrothermal approach to obtain with high saturation magnetization properties. Two series of iron precursors (sulfates and chlorides) were used in synthesis process by varying the reaction temperature at a constant pH. The X-ray diffraction pattern indicates the inverse spinel structure of the synthesized IONPs. The Field emission scanning electron microscopy and high resolution transmission electron microscopy studies revealed that the particles prepared using iron sulfate were consisting a mixer of spherical (16-40 nm) and rod (diameter 20-25 nm, length <100 nm) morphologies that synthesized at 130 °C, while the IONPs synthesized by iron chlorides are found to be well distributed spherical shapes with size range 5-20 nm. On other hand, the IONPs synthesized at reaction temperature of 190 °C has spherical (16-46 nm) morphology in both series. The band gap values of IONPs were calculated from the obtained optical absorption spectra of the samples. The IONPs synthesized using iron sulfate at temperature of 130 °C exhibited high saturation magnetization (MS) of 103.017 emu/g and low remanant magnetization (Mr) of 0.22 emu/g with coercivity (Hc) of 70.9 Oe, which may be attributed to the smaller magnetic domains (dm) and dead magnetic layer thickness (t).

  14. Synthesis and Characterization of Nanostructure Transition Metal Oxides Extracted from Industrial Waste (EOFD) by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Girisun, T. C. Sabari; Babeela, C.; Vidhya, V.

    2011-10-01

    Electric oil furnace dust (EOFD) is a solid waste generated in the collection of particulate material during steelmaking process in electric and oil furnaces. Over 7 million metric tons dust produced per annum in worldwide creates deep impacts like soil, ground water and ecology pollutions. This article reports the simple one step process for the extraction of nanostructured metal oxides from the industrial waste (EOFD) for the realization of low cost solar applications. By hydrothermal technique valuable metals were obtained in the form of metal oxides. Initially the presence of metals was identified by ICP analysis. XRD analysis confirms the formation of nano structured titanium oxide (TiO) along with traces of iron oxide (Fe2O3). The surface morphology and the particle size were analyzed by SEM analysis. Thus the metal oxides derived could be helpful to reduce the burden on the environment, increase the development of the source nano material and reduce the cost of raw materials for solar cell applications.

  15. Effects of pH on physicochemical properties of nanocrystalline TiO2 synthesized via sol-gel hydrothermal method

    NASA Astrophysics Data System (ADS)

    Ahmad, Ita Athirah; Ramli, Anita; Babaa, Moulay-Rachid

    2012-11-01

    Titanium dioxide (TiO2) has been extensively studied as it can be applied to many different applications. TiO2 nanomaterial has several unique properties that enable them to be desirable for many applications and make the production of TiO2 nanomaterial very important and in demand. Multitude of methods and processes are available to synthesize these TiO2 nanomaterials. The ability to manipulate and control the method is the key in producing these nanomaterials with specific properties for the desired applications. Sol-gel hydrothermal is a very flexible and cost-effective method that has been employed to produce TiO2 nanocrystalline. This paper presents the experimental study on the method to produce titanium dioxide (TiO2) nanocrystalline by using sol-gel hydrothermal method. A simple sol-gel hydrothermal technique which is easily controlled and reproduced is done to obtain nanocrystalline titanium dioxide (TiO2). By hydrolyzing titanium tetrachloride, TiCl4 in a mixture of hydrochloric acid (HCl) and deionized water, TiO2 nanopowder was obtained after calcinations at 400 °C. The samples were characterized by Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM) and UV-Vis spectroscopy to study their physicochemical properties. From the result obtained, it shows that TiO2 nanocrystalline is well synthesized at pH 2 with estimated size of 10-20 nm and also have the highest absorption intensity compared to other samples.

  16. Novel bismuth tri-iodide nanostructures obtained by the hydrothermal method and electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Aguiar, Ivana; Olivera, Alvaro; Mombrú, Maia; Bentos Pereira, Heinkel; Fornaro, Laura

    2017-01-01

    Bismuth tri-iodide is a layered compound semiconductor which has suitable properties as material for ionizing radiation detection devices. Monocrystals and polycrystalline thin films have been studied for this application, but only recently, the development of nanostructures of this compound has emerged as an interesting alternative for using such nanostructures in new types of radiation detectors or for including them in other applications. Considering this, we present in this work BiI3 nanoparticles successfully synthesized by the hydrothermal method, using a Teflon-lined stainless steel autoclave, at a temperature of 180 °C during 8-20 h, with BiCl3 and NaI as source materials. We characterized the nanoparticles by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron dispersive spectroscopy (EDS). We obtained small rounded or hexagonal particles (10-20 nm in size) and larger structures. The maximum orientation of the nanostructures is along the (0 0 l) family planes and occurs after 16 h of synthesis, which arises as the best condition for obtaining BiI3 oriented nanostructures. When a 100 kV TEM electron beam was converged on the larger structures, we obtained highly oriented BiI3 hexagonal and rod shaped nanostructures. We found that particles' shape does not depend on the synthesis time. In addition, results were compared with the ones obtained for nanoparticles synthesized from solution. The present work is an advance in the synthesis of BiI3 nanostructures by the hydrothermal method, and is also the first step on seeking the amenable control of morphology and size of such structures using electron beam irradiation. This last process may be particularly appropriate for producing nanostructures for future applications in new devices.

  17. Hydrazine-hydrothermal method to synthesize three-dimensional chalcogenide framework for photocatalytic hydrogen generation

    SciTech Connect

    Liu Yi; Kanhere, Pushkar D.; Wong, Chui Ling; Tian Yuefeng; Feng Yuhua; Boey, Freddy; Wu, Tom; Chen Hongyu; White, Tim J.; Chen Zhong; Zhang Qichun

    2010-11-15

    A novel chalcogenide, [Mn{sub 2}Sb{sub 2}S{sub 5}(N{sub 2}H{sub 4}){sub 3}] (1), has been synthesized by the hydrazine-hydrothermal method. X-ray crystallography study reveals that the new compound 1 crystallizes in space group P1-bar (no. 2) of the triclinic system. The structure features an open neutral three-dimensional framework, where two-dimensional mesh-like inorganic layers are bridged by intra- and inter-layer hydrazine ligands. Both two Mn1 and Mn2 sites adopt distorted octahedral coordination. While two Sb1 and Sb2 sites exhibit two different coordination geometries, the Sb1 site is coordinated with three S atoms to generate a SbS{sub 3} trigonal-pyramidal geometry, and the Sb2 site adopts a SbS{sub 4} trigonal bipyramidal coordination geometry. It has an optical band gap of about {approx}2.09 eV, which was deduced from the diffuse reflectance spectrum, and displays photocatalytic behaviors under visible light irradiation. Magnetic susceptibility measurements show compound 1 obeys the Curie-Weiss law in the range of 50-300 K. -- Graphical abstract: A novel chalcogenide, [Mn{sub 2}Sb{sub 2}S{sub 5}(N{sub 2}H{sub 4}){sub 3}] (1), synthesized by hydrazine-hydrothermal method, has a band gap of about {approx}2.09 eV and displays photocatalytic behaviors under visible light irradiation. Display Omitted

  18. A Simple Graphical Method to Determine the Order in Catalyst

    PubMed Central

    2016-01-01

    Abstract A graphical analysis to elucidate the order in catalyst is presented. This analysis uses a normalized time scale, t [cat]T n, to adjust entire reaction profiles constructed with concentration data. The method is fast and simple to perform because it directly uses the concentration data, therefore avoiding the data handling that is usually required to extract rates. Compared to methods that use rates, the normalized time scale analysis requires fewer experiments and minimizes the effects of experimental errors by using information on the entire reaction profile. PMID:26749539

  19. Simple Thermal Decompose Method for Synthesis of Nickel Disulfide Nanostructures

    NASA Astrophysics Data System (ADS)

    Seyghalkar, Hamideh; Sabet, Mohammad; Salavati-Niasari, Masoud

    2016-11-01

    In this work, a simple thermal decompose method was served to synthesize NiS2 nanostructures via a nickel complex. Also polyethylene glycol (PEG) was used as surfactant to increase the steric effect around nanostructure surfaces and decrease the particles size. The product was characterized with different analysis methods. The crystal structure of the product was studied by X-ray diffraction (XRD) pattern. The particle size and morphology were investigated by scanning electron microscopy (SEM). To study the nanostructures surface purity, Fourier transform infrared spectroscopy (FT-IR) was used. And finally to study the optical properties of the product photoluminescence (PL) spectroscopy was served.

  20. A simple method to calibrate intensities of photographic slit spectrograms

    NASA Astrophysics Data System (ADS)

    Vogt, N.; Barrera, L. H.

    1985-07-01

    A wavelength-dependent intensity calibration of photographic spectrograms can be obtained through the spectrograph without any additional equipment beyond a simple neutral density filter of known transparency. This filter is introduced in the focal plane of the telescope covering part of the spectrograph slit. Exposure of the comparison lamps through the entire slit yields a calibration plate which shows a well defined density jump within each line. From the height of this jump (for many lines of widely ranging strengths) the characteristic curve can be derived. The method is described and compared to the classical calibration method with a tube sensitometer.

  1. ZnS/Ni{sub 2}P core/shell composites: Simple hydrothermal synthesis, characterization and its photocatalytic degradation of pyronine B

    SciTech Connect

    Liu, Shuling; Ma, Lanbing; Zhang, Hongzhe; Ma, Chenlu

    2016-05-15

    Highlights: • ZnS/Ni{sub 2}P composites have been firstly synthesized via a gentle hydrothermal route. • The composites have been characterized by XRD, SEM and TEM. • ZnS/Ni{sub 2}P showed enhanced photocatalytic degradation activity for pyronine B. • The reason for the enhanced photocatalytic activity has been discussed. - Abstract: ZnS/Ni{sub 2}P core/shell composites were successfully synthesized using a hydrothermal method. The composites have been characterized by XRD, SEM, TEM and the corresponding results showed that the composites were composed of the cubic ZnS microspheres, which were made up of ZnS nanoparticles, and Ni{sub 2}P nanoparticles coated on the surfaces of ZnS microspheres. Compared with ZnS microspheres, ZnS/Ni{sub 2}P core/shell composites showed enhanced photocatalytic degradation activity for pyronine B under UV irradiation. This may be related to the effective separation of photogenerated electron–hole pairs in ZnS/Ni{sub 2}P composites which can greatly reduce the chance of their recombination. Furthermore, superoxide ions and hydroxyl radical can be more easily produced through ZnS/Ni{sub 2}P composites, which is also beneficial for the degradation of pyronine B.

  2. Methods for quantifying simple gravity sensing in Drosophila melanogaster.

    PubMed

    Inagaki, Hidehiko K; Kamikouchi, Azusa; Ito, Kei

    2010-01-01

    Perception of gravity is essential for animals: most animals possess specific sense organs to detect the direction of the gravitational force. Little is known, however, about the molecular and neural mechanisms underlying their behavioral responses to gravity. Drosophila melanogaster, having a rather simple nervous system and a large variety of molecular genetic tools available, serves as an ideal model for analyzing the mechanisms underlying gravity sensing. Here we describe an assay to measure simple gravity responses of flies behaviorally. This method can be applied for screening genetic mutants of gravity perception. Furthermore, in combination with recent genetic techniques to silence or activate selective sets of neurons, it serves as a powerful tool to systematically identify neural substrates required for the proper behavioral responses to gravity. The assay requires 10 min to perform, and two experiments can be performed simultaneously, enabling 12 experiments per hour.

  3. Magnetic properties and phase transformations of iron sulfides synthesized under the hydrothermal method

    NASA Astrophysics Data System (ADS)

    Li, S. H.; Chen, Y. H.

    2016-12-01

    The iron sulfide nano-minerals possess advantages of high abundance, low cost, and low toxicity. These advantages make them be competitive in the magnetic, electronic, and photoelectric applications. Mackinawite can be used in soil or water remediations. Greigite is very important for paleomagnetic and geochemical environment studies and the anode materials for lithium ion batteries. Besides, greigite is also utilized for hyperthermia and biomedicine. Pyrrhotite can be applied as geothermometry. Due to the above-mentioned reasons, iron sulfide minerals have specific significances and they must be further investigated, like their phase transformations, magnetic properties, and etc. In this study, the iron sulfide minerals were synthesized by using a hydrothermal method. The ex-situ and in-situ X-ray diffraction (XRD) was used to examine the crystal structure and phase transformation of iron sulfide minerals. The Transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) were carried out to investigate their morphology and magnetic properties, respectively. The results suggested that the phase transformation sequence was followed the order: mackinawite → greigite → (smythite) → pyrrhotite. Two pure mineral phases of greigite and pyrrhotite were obtained under the hydrothermal conditions. The morphology of the pure greigite is granular aggregates with a particle size of approximately 30 nm and pyrrhotite presented a hexagonal sheet stacking with a particle size of thousands nanometers. The greigite had a ferri-magnetic behavior and pyrrhotite was weak ferro-magnetic. Both of them had a pseudo-single magnetic domain (PSD) based on the Day's plot from SQUID data. The complete phase-transformation pathways and high magnetization of iron sulfide minerals are observed in this study and these kind of iron sulfide minerals are worthy to further study.

  4. THE CONTOUR METHOD: SIMPLE 2-D MAPPING OF RESIDUAL STRESSES

    SciTech Connect

    M. PRIME; A. GONZALES

    2000-06-01

    We present an entirely new method for measuring residual stress that is extremely simple to apply yet more powerful than existing techniques. In this method, a part is carefully cut in two. The contour of the resulting new surface is measured to determine the displacements normal to the surface caused by the release of the residual stresses. Analytically, the opposite of these measured displacements are applied as boundary conditions to the surface in a finite element model. By Bueckner's superposition principle, this gives the original residual stresses normal to the plane of the cut. Unlike other relaxation methods for measuring residual stress, the measured data can be used to solve directly for the stresses without a tedious inversion technique. At the same time, an arbitrary two-dimensional variation in stresses can be determined. We demonstrate the method on a steel specimen with a known residual stress profile.

  5. Robustifying blind image deblurring methods by simple filters

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Zeng, Xiangrong; Huangpeng, Qizi; Fan, Jun; Zhou, Jinglun; Feng, Jing

    2016-07-01

    The state-of-the-art blind image deblurring (BID) methods are sensitive to noise, and most of them can deal with only small levels of Gaussian noise. In this paper, we use simple filters to present a robust BID framework which is able to robustify exiting BID methods to high-level Gaussian noise or/and Non-Gaussian noise. Experiments on images in presence of Gaussian noise, impulse noise (salt-and-pepper noise and random-valued noise) and mixed Gaussian-impulse noise, and a real-world blurry and noisy image show that the proposed method can faster estimate sharper kernels and better images, than that obtained by other methods.

  6. Microdevice DNA forensics by the simple tandem repeat method.

    PubMed

    Goedecke, Nils; McKenna, Brian; El-Difrawy, Sameh; Gismondi, Elizabeth; Swenson, Abigail; Carey, Loucinda; Matsudaira, Paul; Ehrlich, Daniel J

    2006-04-14

    We review recent experiments on DNA forensics by the simple tandem repeat (STR) method using a 16-lane micromachined device as the active separation element. Separations by linear polyacrylamide matrices show very high data quality metrics when evaluated with statistically significant data sets. Full 16-locus multiplexes are verified on the multilane system. Multi-donor mixed samples are studied in the context of the limits of the laser-induced fluorescence detector and data-reduction software. The microdevice appears to be posed to outperform current capillary arrays in terms of stability and, through specialized sample loading, in the interpretation of complex mixtures.

  7. A simple method to convert sink particles into stars

    NASA Astrophysics Data System (ADS)

    Sormani, Mattia C.; Treß, Robin G.; Klessen, Ralf S.; Glover, Simon C. O.

    2017-04-01

    Hydrodynamical simulations of star formation often do not possess the dynamic range needed to fully resolve the build-up of individual stars and star clusters, and thus have to resort to sub-grid models. A popular way to do this is by introducing Lagrangian sink particles, which replace contracting high-density regions at the point where the resolution limit is reached. A common problem then is how to assign fundamental stellar properties to sink particles, such as the distribution of stellar masses. We present a new and simple statistical method to assign stellar contents to sink particles. Once the stellar content is specified, it can be used to determine a sink particle's radiative output, supernovae rate or other feedback parameters that may be required in the calculations. Advantages of our method are: (i) it is simple to implement; (ii) it guarantees that the obtained stellar populations are good samples of the initial mass function; (iii) it can easily deal with infalling mass accreted at later times; and (iv) it does not put restrictions on the sink particles' masses in order to be used. The method works very well for sink particles that represent large star clusters and for which the stellar mass function is well sampled, but can also handle the transition to sink particles that represent a small number of stars.

  8. Percutaneous method of management of simple bone cyst.

    PubMed

    Lakhwani, O P

    2013-01-01

    Introduction. Simple bone cyst or unicameral bone cysts are benign osteolytic lesions seen in metadiaphysis of long bones in growing children. Various treatment modalities with variable outcomes have been described in the literature. The case report illustrates the surgical technique of minimally invasive method of treatment. Case Study. A 14-year-old boy was diagnosed as active simple bone cyst proximal humerus with pathological fracture. The patient was treated by minimally invasive percutaneous curettage with titanium elastic nail (TENS) and allogenic bone grafting mixed with bone marrow under image intensifier guidance. Results. Pathological fracture was healed and allograft filled in the cavity was well taken up. The patient achieved full range of motion with successful outcome. Conclusion. Minimally invasive percutaneous method using elastic intramedullary nail gives benefit of curettage cyst decompression and stabilization of fracture. Allogenic bone graft fills the cavity and healing of lesion by osteointegration. This method may be considered with advantage of minimally invasive technique in treatment of benign cystic lesions of bone, and the level of evidence was therapeutic level V.

  9. Controlled growth of well-aligned ZnO nanorod arrays by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Mihailova, I.; Gerbreders, V.; Bulanovs, A.; Tamanis, E.; Sledevskis, E.; Ogurcovs, A.; Sarajevs, P.

    2014-10-01

    The application prospect of zinc oxide (ZnO) nanostructures largely relies on the ability to grow nanoobjects with necessary geometry. In this study well-aligned ZnO nanorod arrays with a high density and uniformity were successfully synthesized on the glass substrates by a hydrothermal method at low-temperature. The aqueous solutions of zinc nitrate hexahydrate and hexamethylenetetramine was used. The effect of seed layer (obtained by electrochemical method and by vacuum deposition method) on the alignment of ZnO nanorods has been investigated. The morphological properties of the ZnO nanorods were also examined in accordance with varying the magnetron sputtering angle for ZnO seeds deposition. It is also shown that the electric field can control the direction of the growth of ZnO nanorods. Morphological, structural and compositional characterizations of obtained films were carried out by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis methods.

  10. Digitization of photographic slides: simple, effective, fast, and inexpensive method.

    PubMed

    Camarena, Lázaro Cárdenas; Guerrero, María Teresa

    2002-03-01

    The technological evolution has changed multiple areas of plastic surgery, including photography. The photograph is one of the instruments used most by the plastic surgeon, and it cannot be eliminated by technological changes. The principal change in photography is that images can be scanned through digital cameras instead of slides. Despite the multiple advantages that digital photography represents, many surgeons are resisting the change. One of the main reasons for this resistance is the large quantity of photographic slides that need to be digitized to be used at scientific conferences as well as in publications. The methods and existing techniques for digitizing slides are costly and time-consuming, and there is risk for loss of definition and image brightness. The authors present a simple, effective, fast, and inexpensive method for digitizing slides. This method has been validated by various plastic surgeons and is effective for use in multimedia presentations and for paper printouts with publication quality.

  11. A simple method to improve ensemble-based ozone forecasts

    NASA Astrophysics Data System (ADS)

    Pagowski, M.; Grell, G. A.; McKeen, S. A.; Dévényi, D.; Wilczak, J. M.; Bouchet, V.; Gong, W.; McHenry, J.; Peckham, S.; McQueen, J.; Moffet, R.; Tang, Y.

    2005-04-01

    Forecasts from seven air quality models and ozone data collected over the eastern USA and southern Canada during July and August 2004 are used in creating a simple method to improve ensemble-based forecasts of maximum daily 1-hr and 8-hr averaged ozone concentrations. The method minimizes least-square error of ensemble forecasts by assigning weights for its members. The real-time ozone (O3) forecasts from this ensemble of models are statistically evaluated against the ozone observations collected for the AIRNow database comprising more than 350 stations. Application of this method is shown to significantly improve overall statistics (e.g., bias, root mean square error, and index of agreement) of the weighted ensemble compared to the averaged ensemble or any individual ensemble member. If a sufficient number of observations is available, we recommend that weights be calculated daily; if not, a longer training phase will still provide a positive benefit.

  12. A simple inverse design method for pump turbine

    NASA Astrophysics Data System (ADS)

    Yin, Junlian; Li, Jingjing; Wang, Dezhong; Wei, Xianzhu

    2014-03-01

    In this paper, a simple inverse design method is proposed for pump turbine. The main point of this method is that the blade loading distribution is first extracted from an existing model and then applied in the new design. As an example, the blade loading distribution of the runner designed with head 200m, was analyzed. And then, the combination of the extracted blade loading and a meridional passage suitable for 500m head is applied to design a new runner project. After CFD and model test, it is shown that the new runner performs very well in terms of efficiency and cavitation. Therefore, as an alternative, the inverse design method can be extended to other design applications.

  13. Magnetic carbon composites with a hierarchical structure for adsorption of tetracycline, prepared from sugarcane bagasse via hydrothermal carbonization coupled with simple heat treatment process.

    PubMed

    Rattanachueskul, Natthanan; Saning, Amonrada; Kaowphong, Sulawan; Chumha, Nawapong; Chuenchom, Laemthong

    2017-02-01

    Sugarcane bagasse, an agricultural waste, was successfully converted into novel magnetic carbon composites by low temperature hydrothermal carbonization at 230°C for 24h, followed by heat treatment at 400°C for only 1h in air. Effects of NaOH and iron loading on the chemical properties of the composites were studied. In addition, various techniques were employed to investigate the physicochemical properties of the composites. Adsorption kinetics and isotherms were investigated with tetracycline (TC) for the magnetic composites. The magnetic carbon composite exhibited 48.35mg/g maximum adsorption capacity and was highly stable chemically and mechanically, with also good magnetic properties. The adsorption of TC by the magnetic adsorbent was mainly attributed to H-bonds and π-π interactions. The results indicate that waste sugarcane bagasse from the sugar industries can be efficiently transformed to a magnetic adsorbent for TC removal via a facile environmentally friendly method.

  14. Controllable synthesis and luminescent properties of novel erythrocyte-like CaMoO4 hierarchical nanostructures via a simple surfactant-free hydrothermal route.

    PubMed

    Luo, Yong-Song; Dai, Xiao-Jun; Zhang, Wei-Dong; Yang, Yang; Sun, Chang Q; Fu, Shao-Yun

    2010-03-07

    Synthesis of metal molybdates (XMoO(4), X = Ca, Sr, Ba) have received much attention recently because of their interesting structural and luminescent properties. Here novel erythrocyte-like CaMoO(4) hierarchical nanostructures are synthesized via a simple surfactant-free hydrothermal route. The formation of the calcium molybdate erythrocytes is controllable through adjusting the fundamental experimental parameters including reaction time, temperature and DMAc to H(2)O ratio. The as-synthesized products are characterized using X-ray powder diffraction, scanning electron microscopy, Brunauer-Emmett-Teller and transmission electron microscopy. The results show that the nucleation and growth of the novel erythrocyte-like CaMoO(4) hierarchical nanostructures are governed by an oriented attachment growth mechanism. The luminescent properties of the CaMoO(4) erythrocytes are then studied using a spectrophotometer and the erythrocyte-like CaMoO(4) nanostructures display a strong blue emission. This study provides an easy surfactant-free synthetic route for the controllable construction of inorganic materials with high hierarchy in the absence of any surfactants.

  15. Fast, simple, and good pan-sharpening method

    NASA Astrophysics Data System (ADS)

    Palubinskas, Gintautas

    2013-01-01

    Pan-sharpening of optical remote sensing multispectral imagery aims to include spatial information from a high-resolution image (high frequencies) into a low-resolution image (low frequencies) while preserving spectral properties of a low-resolution image. From a signal processing view, a general fusion filtering framework (GFF) can be formulated, which is very well suitable for a fusion of multiresolution and multisensor data such as optical-optical and optical-radar imagery. To reduce computation time, a simple and fast variant of GFF-high-pass filtering method (HPFM)-is proposed, which performs filtering in signal domain and thus avoids time-consuming FFT computations. A new joint quality measure based on the combination of two spectral and spatial measures was proposed for quality assessment by a proper normalization of the ranges of variables. Quality and speed of six pan-sharpening methods-component substitution (CS), Gram-Schmidt (GS) sharpening, Ehlers fusion, Amélioration de la Résolution Spatiale par Injection de Structures, GFF, and HPFM-were evaluated for WorldView-2 satellite remote sensing data. Experiments showed that the HPFM method outperforms all the fusion methods used in this study, even its parentage method GFF. Moreover, it is more than four times faster than GFF method and competitive with CS and GS methods in speed.

  16. Vertically aligned ZnO nanorod grown by hydrothermal based chemical method on glass substrate

    NASA Astrophysics Data System (ADS)

    Srivastava, R.; Majumdar, S.; Bhunia, S.

    2012-06-01

    A low-temperature and effective precursor-based method has been demonstrated to synthesize nanostructured ZnO. It is found that the morphology of ZnO precursors has a strong dependence on the reaction conditions that include the molar ratio of reagents, solvent, and reaction temperature. In this work, ZnO nanostructures were synthesized via hydrothermal based chemical method. Zinc acetate dehydrate [Zn(Ac)2 2H2O] and 1-propanol(C3H8O) were adopted for a seed layer growth on glass substrate via spin coating technique. Zinc nitrate hexahydrate [Zn(NO3)2 6H2O], hexamethylenetetramine(C6H12N4) and diethylamine(C4H11N) were adopted as synthesis precursors. The ZnO nanostructures obtained were characterized by scanning electronic microscopy (SEM) and the PL method. The SEM image of the sample showed that the thin film of ZnO on glass substrate has, predominantly, a nanometric rod-like morphology with hexagonal wurtzite structure.

  17. A simple calculation method for determination of equivalent square field.

    PubMed

    Shafiei, Seyed Ali; Hasanzadeh, Hadi; Shafiei, Seyed Ahmad

    2012-04-01

    Determination of the equivalent square fields for rectangular and shielded fields is of great importance in radiotherapy centers and treatment planning software. This is accomplished using standard tables and empirical formulas. The goal of this paper is to present a formula based on analysis of scatter reduction due to inverse square law to obtain equivalent field. Tables are published by different agencies such as ICRU (International Commission on Radiation Units and measurements), which are based on experimental data; but there exist mathematical formulas that yield the equivalent square field of an irregular rectangular field which are used extensively in computation techniques for dose determination. These processes lead to some complicated and time-consuming formulas for which the current study was designed. In this work, considering the portion of scattered radiation in absorbed dose at a point of measurement, a numerical formula was obtained based on which a simple formula was developed to calculate equivalent square field. Using polar coordinate and inverse square law will lead to a simple formula for calculation of equivalent field. The presented method is an analytical approach based on which one can estimate the equivalent square field of a rectangular field and may be used for a shielded field or an off-axis point. Besides, one can calculate equivalent field of rectangular field with the concept of decreased scatter radiation with inverse square law with a good approximation. This method may be useful in computing Percentage Depth Dose and Tissue-Phantom Ratio which are extensively used in treatment planning.

  18. Preparation and magnetic properties of nano size nickel ferrite particles using hydrothermal method

    PubMed Central

    2012-01-01

    Background Nickel ferrite, a kind of soft magnetic materials is one of the most attracting class of materials due to its interesting and important properties and has many technical applications, such as in catalysis, sensors and so on. In this paper the synthesis of NiFe2O4 nanoparticles by the hydrothermal method is reported and the inhibition of surfactant (Glycerol or Sodium dodecyl sulfate) on the particles growth is investigated. Methods For investigation of the inhibition effect of surfactant on NiFe2O4 particles growth, the samples were prepared in presence of Glycerol and Sodium dodecyl sulfate. The X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and inductively coupled plasma atomic emission spectrometer (ICP-AES) techniques were used to characterize the samples. Results The results of XRD and ICP-AES show that the products were pure NiFe2O4 and also nanoparticles grow with increasing the temperature, while surfactant prevents the particle growth under the same condition. The average particle size was determined from the Scherrer's equation and TEM micrographs and found to be in the range of 50-60 nm that decreased up to 10-15 nm in presence of surfactant. The FT-IR results show two absorption bands near to 603 and 490 cm-1 for the tetrahedral and octahedral sites respectively. Furthermore, the saturated magnetization and coercivity of NiFe2O4 nanoparticles were in the range of 39.60 emu/g and 15.67 Qe that decreased for samples prepared in presence of surfactant. As well as, the nanoparticles exhibited a superparamagnetic behavior at room temperature. Conclusions Nanosized nickel ferrite particles were synthesized with and without surfactant assisted hydrothermal methods. The results show that with increasing of temperature, the crystallinity of nanoparticles is increased. In the presence of surfactants, the crystallinity of NiFe2O4 nanoparticles

  19. A simple encapsulation method for organic optoelectronic devices

    NASA Astrophysics Data System (ADS)

    Sun, Qian-Qian; An, Qiao-Shi; Zhang, Fu-Jun

    2014-08-01

    The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells, have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells (PSCs). The power conversion efficiencies (PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices.

  20. Simple effective tests for beam propagation method programs

    NASA Astrophysics Data System (ADS)

    Dumitrescu, Mihail M.; Iancu, Ovidiu D.; Karam, Jean Michel

    2000-02-01

    In view of the increased need of an effective, practical and unified test set to evalute the modeling capabilities of beam propagation method (BPM) based programs, we prose an incident set of tests to be used for a standard evaluation. The proposed test have been chosen to be simple, easy to implement and enable a fairly good evaluation without the need of any experiment. Interesting aspects of the tests' results and some straightforward, practical criteria to estimate program capabilities and to tune the simulation parameters are presented. A cross-checking between 'Mode Solver' based and BPM based programs is also put into discussion. A paraxial error evaluation method is presented and the transverse mesh influence on the paraxial error is analyzed.

  1. Simple Method for Soil Moisture Estimation from Sentinel-1 Data

    NASA Astrophysics Data System (ADS)

    Gilewski, Pawei Grzegorz; Kedzior, Mateusz Andrzej; Zawadzki, Jaroslaw

    2016-08-01

    In this paper, authors calculated high resolution volumetric soil moisture (SM) by means of the Sentinel- 1 data for the Kampinos National Park in Poland and verified obtained results.To do so, linear regression coefficients (LRC) between in-situ SM measurements and Sentinel-1 radar backscatter values were calculated. Next, LRC were applied to obtain SM estimates from Sentinel-1 data. Sentinel-1 SM was verified against in-situ measurements and low-resolution SMOS SM estimates using Pearson's linear correlation coefficient. Simple SM retrieval method from radar data used in this study gives better results for meadows and when Sentinel-1 data in VH polarisation are used.Further research should be conducted to prove usefulness of proposed method.

  2. A simple method for evaluating data from an interlaboratory study.

    PubMed

    Horwitz, W; Britton, P; Chirtel, S J

    1998-01-01

    Large-scale laboratory- and method-performance studies involving more than about 30 laboratories may be evaluated by calculating the HORRAT ratio for each test sample (HORRAT = [experimentally found among-laboratories relative standard deviation] divided by [relative standard deviation calculated from the Horwitz formula]). The chemical analytical method is deemed acceptable per se if HORRAT approximately 1.0 (+/- 0.5). If HORRAT is > or approximately 2.0, the most extreme values are removed successively until an "acceptable" ratio is obtained. The laboratories responsible for the extreme values that are removed should examine their technique and procedures. If > or approximately 15% of the values have to be removed, the instructions and the methods should be examined. This suggested computation procedure is simple and does not require statistical outlier tables. Proposed action limits may be adjusted according to experience. Data supporting U.S. Environmental Protection Agency method 245.1 for mercury in waters (manual cold-vapor atomic absorption spectrometry), supplemented by subsequent laboratory-performance data, were reexamined in this manner. Method-performance parameters (means and among-laboratories relative standard deviations) were comparable with results from the original statistical analysis that used a robust biweight procedure for outlier removal. The precision of the current controlled performance is better by a factor of 4 than that of estimates resulting from the original method-performance study, at the expense of rejecting more experimental values as outliers.

  3. A simple headspace equilibration method for measuring dissolved methane

    USGS Publications Warehouse

    Magen, C; Lapham, L.L.; Pohlman, John W.; Marshall, Kristin N.; Bosman, S.; Casso, Michael; Chanton, J.P.

    2014-01-01

    Dissolved methane concentrations in the ocean are close to equilibrium with the atmosphere. Because methane is only sparingly soluble in seawater, measuring it without contamination is challenging for samples collected and processed in the presence of air. Several methods for analyzing dissolved methane are described in the literature, yet none has conducted a thorough assessment of the method yield, contamination issues during collection, transport and storage, and the effect of temperature changes and preservative. Previous extraction methods transfer methane from water to gas by either a "sparge and trap" or a "headspace equilibration" technique. The gas is then analyzed for methane by gas chromatography. Here, we revisit the headspace equilibration technique and describe a simple, inexpensive, and reliable method to measure methane in fresh and seawater, regardless of concentration. Within the range of concentrations typically found in surface seawaters (2-1000 nmol L-1), the yield of the method nears 100% of what is expected from solubility calculation following the addition of known amount of methane. In addition to being sensitive (detection limit of 0.1 ppmv, or 0.74 nmol L-1), this method requires less than 10 min per sample, and does not use highly toxic chemicals. It can be conducted with minimum materials and does not require the use of a gas chromatograph at the collection site. It can therefore be used in various remote working environments and conditions.

  4. Determination of the age of hydrothermal fluids by the kinetic-geochemical method

    SciTech Connect

    Reznikov, A.N.

    1995-03-01

    An estimate of the age of hydrothermal fluids at rift zones of oceans and continents, island arc regions, as well as regions of mud volcanism and occurrences of condensation and solution waters of hydrocarbon accumulations is given on the basis of the chemical, gas, and isotopic compositions and geothermobaric conditions. Correlations between the degree of accumulation of trace elements in hydrothermal fluids and their age were established.

  5. Acoustic measurement method of the volume flux of a seafloor hydrothermal plume

    NASA Astrophysics Data System (ADS)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.

    2011-12-01

    Measuring fluxes (volume, chemical, heat, etc.) of the deep sea hydrothermal vents has been a crucial but challenging task faced by the scientific community since the discovery of the vent systems. However, the great depths and complexities of the hydrothermal vents make traditional sampling methods laborious and almost daunting missions. Furthermore, the samples, in most cases both sparse in space and sporadic in time, are hardly enough to provide a result with moderate uncertainty. In September 2010, our Cabled Observatory Vent Imaging Sonar System (COVIS, http://vizlab.rutgers.edu/AcoustImag/covis.html) was connected to the Neptune Canada underwater ocean observatory network (http://www.neptunecanada.ca) at the Main Endeavour vent field on the Endeavour segment of the Juan de Fuca Ridge. During the experiment, the COVIS system produced 3D images of the buoyant plume discharged from the vent complex Grotto by measuring the back-scattering intensity of the acoustic signal. Building on the methodology developed in our previous work, the vertical flow velocity of the plume is estimated from the Doppler shift of the acoustic signal using geometric correction to compensate for the ambient horizontal currents. A Gaussian distribution curve is fitted to the horizontal back-scattering intensity profile to determine the back-scattering intensity at the boundary of the plume. Such a boundary value is used as the threshold in a window function for separating the plume from background signal. Finally, the volume flux is obtained by integrating the resulting 2D vertical velocity profile over the horizontal cross-section of the plume. In this presentation, we discuss preliminary results from the COVIS experiment. In addition, several alternative approaches are applied to determination of the accuracy of the estimated plume vertical velocity in the absence of direct measurements. First, the results from our previous experiment (conducted in 2000 at the same vent complex using a

  6. A design method for robust stabilizing simple repetitive control systems

    NASA Astrophysics Data System (ADS)

    Yamada, Kou; Takenaga, Hiroshi; Tanaka, Hiroshi

    2007-12-01

    The modified repetitive control system is a type of servomechanism for the periodic reference input. That is, the modified repetitive control system follows the periodic reference input with small steady state error, even if a periodic disturbance or uncertainty exists in the plant. Using previously proposed modified repetitive controllers, even if the plants does not includes time-delay, the transfer function from the periodic reference input to the output and that from the disturbance to the output have an infinite number of poles. When the transfer function from the periodic reference input to the output and that from the disturbance to the output have an infinite number of poles, it is difficult to specify the input-output characteristic and the disturbance attenuation characteristic. From the practical point of view, it is desirable that the input-output characteristic and the disturbance attenuation characteristic are easily specified. In order to specify the input-output characteristic and the disturbance attenuation characteristic easily, the transfer function from the periodic reference input to the output and that from the disturbance to the output are desirable to have a finite number of poles. Yamada et al. proposed the concept of simple repetitive control systems such that the controller works as a modified repetitive controller and the transfer function from the periodic reference input to the output and that from the disturbance to the output have a finite number of poles. In addition, Yamada et al. clarified the parametrization of all stabilizing simple repetitive controllers. However the method by Yamada et al. cannot be applied for the plant with uncertainty. The purpose of this paper is to propose the parametrization of all robust stabilizing simple repetitive controllers for the plant with uncertainty.

  7. Quality and high yield synthesis of Ag nanowires by microwave-assisted hydrothermal method.

    PubMed

    Meléndrez, Manuel F; Medina, Carlos; Solis-Pomar, Francisco; Flores, Paulo; Paulraj, Mani; Pérez-Tijerina, Eduardo

    2015-01-01

    Silver nanowires (Ag-NWs) were obtained using microwave-assisted hydrothermal method (MAH). The main advantage of the method is its high NWs production which is greater than 90%. It is also easy, fast, and highly reproducible process. One of the drawbacks presented so far in the synthesis of nanostructures by polyol path is the high temperature used in the process, which is superior than the boiling point of solvent (ethylene glycol), and also its excessive reaction time. Here, Ag-NWs with diameters of 70 to 110 nm were synthesized in 5 min in large quantities. Results showed that dimensions and shape of nanowires were very susceptible to changes with reaction parameters. The reactor power and reactor fill capacity were important for the synthesis. It was found that the reaction time needs to be decreased because of the NWs which start to deform and break up due to significant increase in the pressure's system. Energy-dispersive X-ray spectroscopy and electron diffraction analysis (SAED) did not show corresponding phases of AgO. Some aspects about synthesis parameters which are related to the percent yield and size of nanowires are also discussed.

  8. Phenology of Net Ecosystem Exchange: A Simple Estimation Method

    NASA Astrophysics Data System (ADS)

    Losleben, M. V.

    2007-12-01

    Carbon sequestration is important to global carbon budget and ecosystem function and dynamics research. Direct measurement of Net Ecosystem Exchange (NEE), a measure of the carbon sequestration of an ecosystem, is instrument, labor, and fiscally intensive, thus there is value to establish a simple, robust estimation method. Six ecosystem types across the United States, ranging from deciduous and coniferous forests to desert shrub land and grasslands, are compared. Initial results suggest instrumentally measured NEE and this proxy method are promising, showing excellent temporal matches of the two methods for onset and termination of carbon sequestration in a sub-alpine forest for the study period, 1997-2006. Moreover, the similarity of climatic signatures in all six ecosystems of this study suggests this proxy estimation method may be widely applicable across diverse environmental zones This estimation method is simply the interpretation of annual accumulated daily precipitation plotted against the annual daily accumulated degree growing days above a zero degree C base. Applicability at sub-seasonal time scales will also be discussed in this presentation.

  9. Synthesis and Magnetic Properties of Nearly Monodisperse CoFe2O4Nanoparticles Through a Simple Hydrothermal Condition

    PubMed Central

    2010-01-01

    Nearly monodisperse cobalt ferrite (CoFe2O4) nanoparticles without any size-selection process have been prepared through an alluring method in an oleylamine/ethanol/water system. Well-defined nanospheres with an average size of 5.5 nm have been synthesized using metal chloride as the law materials and oleic amine as the capping agent, through a general liquid–solid-solution (LSS) process. Magnetic measurement indicates that the particles exhibit a very high coercivity at 10 K and perform superparamagnetism at room temperature which is further illuminated by ZFC/FC curves. These superparamagnetic cobalt ferrite nanomaterials are considered to have potential application in the fields of biomedicine. The synthesis method is possible to be a general approach for the preparation of other pure binary and ternary compounds. PMID:20672131

  10. METEORIC-HYDROTHERMAL SYSTEMS.

    USGS Publications Warehouse

    Criss, Robert E.; Taylor, Hugh P.

    1986-01-01

    This paper summarizes the salient characteristics of meteoric-hydrothermal systems, emphasing the isotopic systematics. Discussions of permeable-medium fluid dynamics and the geology and geochemistry of modern geothermal systems are also provided, because they are essential to any understanding of hydrothermal circulation. The main focus of the paper is on regions of ancient meteoric-hydrothermal activity, which give us information about the presently inaccessible, deep-level parts of modern geothermal systems. It is shown oxygen and hydrogen isotopes provide a powerful method to discover and map fossil hydrothermal systems and to investigate diverse associated aspects of rock alteration and ore deposition.

  11. A simple method for positional analysis of phosphatidylcholine.

    PubMed

    Kiełbowicz, Grzegorz; Gładkowski, Witold; Chojnacka, Anna; Wawrzeńczyk, Czesław

    2012-12-15

    Simple and fast method of positional analysis of fatty acid composition of phosphatidylcholine (PC) from egg-yolk and soy has been elaborated. The key step of the procedure was complete ethanolysis of PC catalyzed by sn-1,3 specific lipase from Mucor miehei (Lipozyme). 2-Acyl-lysophosphatidylcholine (2-acyl LPC), fatty acids ethyl esters (FAEEs) and free fatty acids (FAs) were formed in this process. No acyl migration was observed during the reaction. The products were entirely separated from the products mixture by simple extraction in water:hexane (2:3 v/v) system. The hexane fraction containing free FAs and FAEEs was treated with BF(3)/Et(2)O in ethanol to obtain only FAEEs. The analysis of FAEEs by GC gave the composition of the FAs in the sn-1 position of the PC. 2-Acyl LPC from water fraction after precipitation in cold (-20°C) acetone was converted into FAEEs and analyzed by gas chromatography (GC) to determine FAs composition in the sn-2 position of the PC.

  12. Simple and sensitive spectrophotometric methods for determination of amantadine hydrochloride

    NASA Astrophysics Data System (ADS)

    Darwish, I. A.; Khedr, A. S.; Askal, H. F.; Mahmoud, R. M.

    2006-11-01

    Three simple and sensitive spectrophotometric methods (A-C) for determination of amantadine hydro-chloride have been developed and validated. The first method (A) is based on the oxidation of the drug by ammonium molybdate. The second method (B) was based on the charge-transfer complexation reaction between the amantadine base as an electron donor and iodine as a σ-acceptor. The third method (C) is based on the reaction of N-alkylvinylamine formed from the interaction of the free amino group in amantadine molecule and acetalde-hyde with chloranil to give colored vinylamino-substituted benzoquinone. The colored products of these reactions were measured at their corresponding maximum absorption peaks. Different variables affecting the reactions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients 0.9993-0.9998 were found between the reading and the corresponding concentration of the drug in the range 2-90 µg·ml-1. The limits of detection ranged from 0.16 to 1.91 µg·ml-1. The precision of the methods was satisfactory: the values of relative standard deviation did not exceed 1.63%. The proposed methods were successfully applied to the analysis of amantadine HCl in its capsules with good accuracy and precision; the label claim percentages ranged from 99.8 to 100.5 ± (0.52-1.22) %. The results obtained by the proposed spectrophotometric methods were comparable with those obtained by the official method.

  13. A simple method to induce focal brain hypothermia in rats.

    PubMed

    Clark, Darren L; Colbourne, Frederick

    2007-01-01

    Hypothermia reduces cell death and promotes recovery in models of cerebral ischemia, intracerebral hemorrhage and trauma. Clinical studies report significant benefit for treating cardiac arrest and studies are investigating hypothermia for stroke and related conditions. Both local (head) and generalized hypothermia have been used. However, selective brain cooling has fewer side effects than systemic cooling. In this study, we developed a method to induce local (hemispheric) brain hypothermia in rats. The method involves using a small metal coil implanted between the Temporalis muscle and adjacent skull. This coil is then cooled by flushing it with cold water. In our first experiment, we tested whether this method induces focal brain hypothermia in anesthetized rats. Brain temperature was assessed in the ipsilateral cortex and striatum, and contralateral striatum, while body temperature was kept normothermic. Focal, ipsilateral cooling was successfully produced, while the other locations remained normothermic. In the second experiment, we implanted the coil, and brain and body temperature telemetry probes. The coil was connected via overhead swivel to a cold-water source. Brain hypothermia was produced for 24 h, while body temperature remained normothermic. A third experiment measured brain and body temperature along with heart rate and blood pressure. Brain cooling was produced for 24 h without significant alterations in pressure, heart rate or body temperature. In summary, our simple method allows for focal brain hypothermia to be safely induced in anesthetized or conscious rats, and is, therefore, ideally suited to stroke and trauma studies.

  14. Non-enzymatic hydrogen peroxide biosensor based on rose-shaped FeMoO{sub 4} nanostructures produced by convenient microwave-hydrothermal method

    SciTech Connect

    Liu, Hongying; Gu, Chunchuan; Li, Dujuan; Zhang, Mingzhen

    2015-04-15

    Graphical abstract: A non-enzymatic H{sub 2}O{sub 2} sensor with high selectivity and sensitivity based on rose-shaped FeMoO{sub 4} synthesized by the convenient microwave-assisted hydrothermal method, was fabricated. - Highlights: • Rose-shaped FeMoO{sub 4} is synthesized within 10 min via microwave-assisted hydrothermal approach. • Non-enzymatic hydrogen peroxide biosensor based on FeMoO{sub 4} nanomaterials is fabricated. • The biosensor exhibits good performance. - Abstract: In this work, we demonstrated a simple, rapid and reliable microwave-assisted hydrothermal approach to synthesize the uniform rose-shaped FeMoO{sub 4} within 10 min. The morphologies of the synthesized materials were characterized by X-ray powder diffraction and scanning electron microscopy. Moreover, a non-enzymatic amperometric sensor for the detection of hydrogen peroxide (H{sub 2}O{sub 2}) was fabricated on the basis of the FeMoO{sub 4} as electrocatalysis. The resulting FeMoO{sub 4} exhibited high sensitivity and good stability for the detection of H{sub 2}O{sub 2}, which may be attributed to the rose-shaped structure of the material and the catalytic property of FeMoO{sub 4}. Amperometric response showed that the modified electrode had a good response for H{sub 2}O{sub 2} with a linear range from 1 μM to 1.6 mM, a detection limit of 0.5 μM (S/N = 3), high selectivity and short response time. Additionally, good recoveries of analytes in real milk samples confirm the reliability of the prepared sensor in practical applications.

  15. A SIMPLE METHOD FOR MEASURING THE ELECTRON-BEAM MAGNETIZATION

    SciTech Connect

    Halavanau, A.; Qiang, G.; Wisniewski, E.; Ha, G.; Power, J.; Piot, P.

    2016-10-18

    There are a number of projects that require magnetized beams, such as electron cooling or aiding in “flat” beam transforms. Here we explore a simple technique to characterize the magnetization, observed through the angular momentum of magnetized beams. These beams are produced through photoemission. The generating drive laser first passes through microlens arrays (fly-eye light condensers) to form a transversely modulated pulse incident on the photocathode surface [1]. The resulting charge distribution is then accelerated from the photocathode. We explore the evolution of the pattern via the relative shearing of the beamlets, providing information about the angular momentum. This method is illustrated through numerical simulations and preliminary measurements carried out at the Argonne Wakefield Accelerator (AWA) facility are presented.

  16. A simple method for rapidly processing HEU from weapons returns

    SciTech Connect

    McLean, W. II; Miller, P.E.

    1994-01-01

    A method based on the use of a high temperature fluidized bed for rapidly oxidizing, homogenizing and down-blending Highly Enriched Uranium (HEU) from dismantled nuclear weapons is presented. This technology directly addresses many of the most important issues that inhibit progress in international commerce in HEU; viz., transaction verification, materials accountability, transportation and environmental safety. The equipment used to carry out the oxidation and blending is simple, inexpensive and highly portable. Mobile facilities to be used for point-of-sale blending and analysis of the product material are presented along with a phased implementation plan that addresses the conversion of HEU derived from domestic weapons and related waste streams as well as material from possible foreign sources such as South Africa or the former Soviet Union.

  17. Killer system: a simple method for differentiating Candida albicans strains.

    PubMed Central

    Polonelli, L; Archibusacci, C; Sestito, M; Morace, G

    1983-01-01

    The killer effect of 37 species of Candida, Cryptococcus, Hansenula, Pichia, Rhodotorula, Saccharomyces, and Trichosporon on 100 Candida albicans isolates of human and animal origin was studied. All of the C. albicans cultures were sensitive to one or more killer yeasts. The factors affecting the killer phenomenon on C. albicans were investigated for realizing a simple system for the differentiation of the 100 C. albicans isolates. By using this system, it was possible to differentiate up to 512 isolates of C. albicans according to their susceptibility to the killer effect of nine selected killer yeasts. The use of this method as an epidemiological marker in the case of presumptive nosocomial infections due to C. albicans is also reported. Images PMID:6345575

  18. A simple inexpensive method for estimating underwater weight.

    PubMed

    Thomas, T R; Cook, P L

    1978-03-01

    A description is given of a simple, inexpensive and versatile method for estimating underwater weight. The use of a portable stock tank allows the determination of % Fat by underwater weighing without requiring a swimming pool, built-in tank, or special facility. Twenty-eight college students were weighed on two separate testing sessions 24-48 hours apart. Ten trials were performed at each session. The mean of the last five trials was used in determining underwater weight. The test-retest reliability coefficient was high, r = 0.98, and most of the successive trial correlations were above 0.99. The mean % Fat for the women (N = 9) was 22.2 +/- 5.9 and for the men (N = 19) was 13.7 +/- 5.1.

  19. A simple design method of negative refractive index metamaterials

    NASA Astrophysics Data System (ADS)

    Kim, Dongho; Lee, Wangju; Choi, Jaeick

    2009-11-01

    We propose a very simple design method of negative refractive index (NRI) materials that can overcome some drawbacks of conventional resonant-type NRI materials. The proposed NRI materials consist of single or double metallic patterns printed on a dielectric substrate. Our metamaterials (MTMs) show two properties that are different from other types of MTMs in obtaining effective negative values of permittivity ( ɛ) and permeability ( μ) simultaneously; the geometrical outlines of the metallic patterns are not confined within any specific shape, and the metallic patterns are printed on only one side of the dielectric substrate. Therefore, they are very easy to design and fabricate using common printed circuit board (PCB) technology according to the appropriate application. Excellent agreement between the experiment and prediction data ensures the validity of our design approach.

  20. A simple gel electrophoresis method for separating polyhedral gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Suhee; Lee, Hye Jin

    2015-07-01

    In this paper, a simple approach to separate differently shaped and sized polyhedral gold nanoparticles (NPs) within colloidal solutions via gel electrophoresis is described. Gel running parameters for separating efficiently gold NPs including gel composition, added surfactant types and applied voltage were investigated. The plasmonic properties and physical structure of the separated NPs extracted from the gel matrix were then investigated using transmission electron microscopy (TEM) and UV-vis spectrophotometry respectively. Data analysis revealed that gel electrophoresis conditions of a 1.5 % agarose gel with 0.1 % sodium dodecyl sulfate (SDS) surfactant under an applied voltage of 100 V resulted in the selective isolation of ~ 50 nm polyhedral shaped gold nanoparticles. Further efforts are underway to apply the method to purify biomolecule-conjugated polyhedral Au NPs that can be readily used for NP-enhanced biosensing platforms.

  1. A simple method to measure NK cell cytotoxicity in vivo.

    PubMed

    Saudemont, Aurore; Burke, Shannon; Colucci, Francesco

    2010-01-01

    Natural killer (NK) cells were discovered in the 1970 s and named after their naturally occurring cytotoxic activity against tumor cells. It has recently become clear that NK cells are not just killers and that malignancy is unlikely to be the selective pressure driving the evolution of NK cells. Indeed, NK cells secrete a host of cytokines and chemokines that contribute to tissue remodeling at the feto-maternal interface and to both innate and adaptive immunity during infection. Moreover, in certain conditions, they cannot deliver functions cell autonomously, as they require priming from other cells, namely dendritic cells. Nevertheless, natural cytotoxicity is still considered an important parameter used to evaluate NK cell biology, both in the clinic and in the research lab. In this chapter we describe a simple method to quantify spontaneous NK cell cytotoxicity in vivo.

  2. Improved dye-sensitized solar cell with a ZnO nanotree photoanode by hydrothermal method

    PubMed Central

    2014-01-01

    This study investigated the influence of ZnO nanostructures on dye adsorption to increase the photovoltaic conversion efficiency of solar cells. ZnO nanostructures were grown in both tree-like and nanorod (NR) arrays on an AZO/FTO film structure by using a hydrothermal method. The results were observed in detail using X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), UV-visible spectrophotometry, electrochemical impedance spectroscopy, and solar simulation. The selective growth of tree-like ZnO was found to exhibit higher dye adsorption loading and conversion efficiency than ZnO NRs. The multiple ‘branches’ of ‘tree-like nanostructures’ increases the surface area for higher light harvesting and dye loading while reducing charge recombination. These improvements result in a 15% enhancement in power conversion. The objective of this study is to facilitate the development of a ZnO-based dye-sensitized solar cell. PMID:24872799

  3. Effect of anneal temperature on fluorine doped tin oxide (FTO) nanostructured fabricated using hydrothermal method

    NASA Astrophysics Data System (ADS)

    Ahmad, M. K.; Marzuki, N. A.; Soon, C. F.; Nafarizal, N.; Sanudin, R.; Suriani, A. B.; Mohamed, A.; Shimomura, M.; Murakami, K.; Mamat, M. H.; Malek, M. F.

    2017-01-01

    FTO thin films were prepared by the hydrothermal method at anneal temperature of 100°C-400°C using pentahydrate stannic chloride (SnCl4.5H2O) and ammonium fluoride (NH4F) as precursors, and a mixture of DI water, acetone and hydrochloride as a solvent. The X-ray diffraction studies confirmed the tetragonal structure with polycrystalline nature. The preferred directions of crystal growth appeared in the diffractogram of FTO thin films prepared with different anneal temperature were correspond to the reflection from the (101), (200) and (211) planes, respectively. The electrical study reveals that the films have degenerate and exhibit n-type electrical conductivity. For films prepared at 400°C, the relatively higher transmittance of about 85-90% at 800nm has been observed. The transmission attained in this study is greater than the values reported for tin oxide films prepared at anneal temperature 400°C, from an aqueous solution of SnCl4.5H2O precursor. Resistivity is smaller than the value reported. The obtained results revealed that the structures and properties of the films were greatly affected by anneal temperature

  4. Magnetic properties of hematite (α-Fe2O3) nanoparticles prepared by hydrothermal synthesis method

    NASA Astrophysics Data System (ADS)

    Tadic, Marin; Panjan, Matjaz; Damnjanovic, Vesna; Milosevic, Irena

    2014-11-01

    Hematite (α-Fe2O3) nanoparticles are successfully synthesized by using the hydrothermal synthesis method. An X-ray powder diffraction (XRPD) of the sample shows formation of the nanocrystalline α-Fe2O3 phase. A transmission electron microscopy (TEM) measurements show spherical morphology of the hematite nanoparticles and narrow size distribution. An average hematite nanoparticle size is estimated to be about 8 nm by TEM and XRD. Magnetic properties were measured using a superconducting quantum interference device (SQUID) magnetometry. Investigation of the magnetic properties of hematite nanoparticles showed a divergence between field-cooled (FC) and zero-field-cooled (ZFC) magnetization curves below Tirr = 103 K (irreversibility temperature). The ZFC magnetization curve showed maximum at TB = 52 K (blocking temperature). The sample did not exhibit the Morin transition. The M(H) (magnetization versus magnetic field) dependence at 300 K showed properties of superparamagnetic iron oxide nanoparticles (SPION). The M(H) data were successfully fitted by the Langevin function and magnetic moment μp = 657 μB and diameter d = 8.1 nm were determined. Furthermore, magnetic measurements showed high magnetization at room temperature (MS = 3.98 emu/g), which is desirable for application in spintronics and biomedicine. Core-shell structure of the nanoparticles was used to describe high magnetization of the hematite nanoparticles.

  5. One-step synthesis of titanium oxide nanocrystal- rutile by hydrothermal method

    SciTech Connect

    Yan, Evyan Yang Chia; Zakaria, Sarani; Chia, Chin Hua

    2014-09-03

    Pure rutile phase titanium oxides (TiO{sub 2}) nanocrystals were synthesized via hydrothermal method with titanium tetrachloride (TiCl{sub 4}) and water (H{sub 2}O) treated in an autoclave. The particle size and phase assemblages were characterized using Scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. Band gap energy (E{sub g}) of the nanocrystals was estimated from the Ultra violet – visible light (UV-vis) absorption spectra. It was demonstrated that TiO{sub 2} nanocrystals can be prepared through increasing of temperature and period of treatment. It is believed that the presence of acid chloride (HCl) as by-product during the hydrolysis played an important role in controlling the growth of morphology and crystal structures. The E{sub g} of the samples were estimated from the plot of modified Kubelka-Munk function were in the range of 3.04 – 3.26eV for the samples synthesized at temperature ranging from 50 to 200°C for 16 hours.

  6. Preparation and characterization of ZnS nanoparticles prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Wang, Caifeng; Li, Qingshan; Hu, Bo

    2017-07-01

    ZnS nanoparticles were prepared by hydrothermal method using zinc nitrate [Zn(NO3)2 ṡ 6H2O] and thiourea [SC(NH2)2] as sources of Zn2+ and S2- ions and cetyltrimethyl ammonium bromide [CH3(CH2)15N+(CH3)3 ṡ Br-; CTAB] as a surface active agent. The structural, surface morphology and optical properties of ZnS nanoparticles as a function of growth temperature were investigated. The studies show that ZnS nanoparticles have high transmittance over 70% in the visible light range of 400-800 nm, and it has a strong green emission band at about 520 nm which originates from the recombination of electrons from the energy level of sulfur vacancies with the holes from the energy level of zinc vacancies. With the increase of the growth temperature, the XRD peak intensity and the size of ZnS nanoparticles increase, while the green emission intensity firstly increases and then decreases.

  7. Nanostructured hybrid layered-spinel cathode material synthesized by hydrothermal method for lithium-ion batteries.

    PubMed

    Liu, Cong; Wang, Zhiyuan; Shi, Chunsheng; Liu, Enzuo; He, Chunnian; Zhao, Naiqin

    2014-06-11

    Nanostructured spinel LiMn1.5Ni0.5O4, layered Li1.5Mn0.75Ni0.25O2.5 and layered-spinel hybrid particles have been successfully synthesized by hydrothermal methods. It is found that the nanostructured hybrid cathode contains both spinel and layered components, which could be expressed as Li1.13Mn0.75Ni0.25O2.32. Diffraction-contrast bright-field (BF) and dark-field (DF) images illustrate that the hybrid cathode has well dispersed spinel component. Electrochemical measurements reveal that the first-cycle efficiency of the layered-spinel hybrid cathode is greatly improved (up to 90%) compared with that of the layered material (71%) by integrating spinel component. Our investigation demonstrates that the spinel containing hybrid material delivers a high capacity of 240 mAh g(-1) with good cycling stability between 2.0 and 4.8 V at a current rate of 0.1 C.

  8. Abnormal room temperature ferromagnetism in CuO/ZnO nanocomposites via hydrothermal method

    NASA Astrophysics Data System (ADS)

    Lu, Ping; Zhou, Wei; Li, Ying; Wang, Jianchun; Wu, Ping

    2017-03-01

    CuO/ZnO nanocomposites have been successfully synthesized by a one-step hydrothermal method with different phase ratios. Field emission scanning electron microscopy and transmission electron microscopy results show that the obtained products of nanosheets are composed of small primary particles with an average size of about 20 nm. With the increasing proportion of CuO phase, nanosheets have significant collapse and the amount of small sheets increases obviously. The abnormal room temperature ferromagnetism was discovered at the interface between diamagnetic ZnO and antiferromagnetic CuO, which can be tuned by changing the phase ratios. Optical spectra indicate that the interaction between ZnO and CuO modifies the electronic structure of nanocomposites. XPS results verify the valence change of Cu ions and the presence of oxygen vacancies, which are ultimately responsible for the observed ferromagnetism. The indirect double-exchange model was employed to explain the origin of magnetism. Our study suggests that magnetically functional interfaces exhibit very appealing properties for novel devices.

  9. Preparation of PBO/ZnO fibers by hydrothermal synthesis method and its properties

    NASA Astrophysics Data System (ADS)

    Ma, Qi; Wang, Bin; Lv, Junwei; Li, Yuntao; Li, Hui; Zhao, Chunxia

    2017-08-01

    In this article, zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of PBO fibers through hydrothermal synthesis method. The structures and properties of PBO/ZnO fibers and PBO fibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Thermogravimetric analysis (TG), and tensile testing. The results revealed that the PBO/ZnO fibers have good mechanical properties and high thermal stability. Moreover, the fibers exhibited excellent UV-blocking properties by putting them under UV irradiation of 313 nm. Specifically, ZnO coated fibers will lose only 18.93% of tensile strength after 50 h irradiation, and then will keep over 65% of tensile strength after 100 h UV irradiation. Additionally the interface shear strength is increased significantly, and the results also showed modified PBO fibers exhibited excellent hydrophobic quality. So the functional materials have great potentials in future engineering applications.

  10. Synthesis and photocatalysis properties of ZnO structures with different morphologies via hydrothermal method

    NASA Astrophysics Data System (ADS)

    Xie, Juan; Wang, Hu; Duan, Ming; Zhang, Liehui

    2011-05-01

    The special flower-like and sheet-like ZnO structures were successfully synthesized by hydrothermal method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The photocatalytic activity of different morphologies of ZnO structures was evaluated by degradating of methyl orange (MO). The photocatalytic degradation process was monitored in terms of decolorization and total organic carbon (TOC) removals. The results indicated that the flower-like ZnO structures were consisted of numerous flower-like aggregates with the size of 2 μm. The sheet-like ZnO nanostructures were obtained by increasing the reaction time. They exhibited higher photodegradation efficiencies under UV light irradiation than flower-like ZnO structures due to the blue shift of the band gap. The photodegradation could be described as the pseudo-first-order kinetics with apparent rate constants ranging from 1.17 × 10 -2 to 3.42 × 10 -2 min -1, which were based on the morphology of the structures. The photodegradation was faster than the mineralization, indicating that the accumulation of by-products were resistant to photocatalytic degradation.

  11. Morphology and Properties of (Ba, Sr, Ca) Titanates Synthesized by Microwave-Assisted Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Souza, A. E.; Santos, G. T. A.; Silva, R. A.; Moreira, M. L.; Volante, D. P.; Teixeira, S. R.; Longo, E.

    2011-10-01

    Ba1-xCaxTiO3, Ba1-xSrxTiO3 and Sr1-xCaxTiO3 (x = 0, 0.25, 0.50, 0.75 and 1) nanoparticles were synthesized using the microwave-assisted hydrothermal method. Samples were prepared for 40 minutes at 140°C under a pressure of 3 MPa using an adapted domestic microwave oven. The samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (FE-SEM), and Raman, photoluminescence (PL) and ultraviolet-visible (UV-Vis) spectroscopies. XRD data show that ceramic powders have crystalline phases associated with a short-range structural disorder. This structural disorder is confirmed by Raman spectral bands indicating multi-phonon processes and the presence of defects or impurities. Such defects account for a broad band in the photoluminescence spectrum in the green light (460 nm) region for all samples. Gap energy variation, obtained from UV-Vis spectra, suggest a non-uniform band structure of these titanates in accordance with the PL results. The morphology of each sample is changed with doping and varies from a spherical to cubic appearance for energy minimization.

  12. Synthesis and Enhanced Photocatalytic Activity of Ce-Doped Zinc Oxide Nanorods by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Aisah, N.; Gustiono, D.; Fauzia, V.; Sugihartono, I.; Nuryadi, R.

    2017-02-01

    Zinc oxide (ZnO) is a n-type semiconductor material which has a wide direct band gap energy of ∼ 3.3 eV, and other interesting optical properties, hence it’s potentially applied to various fields such as electronics, optoelectronics, sensors, photonic devices, and also photocatalyst. Dopant in ZnO nanostructures is an effective way to improve ZnO’s structural properties in various applications. In this study, undoped and Ce doped ZnO nanorods were synthesized on ITO coated glass substrates by ultrasonic spray pyrolysis for seeding deposition and hydrothermal methods at a temperature of 95 0C for 2 hours for growth. X-ray diffraction, field emission scanning electron microscopy (FESEM), UV-VIS and Photoluminescence spectroscopy were used to characterize the crystal structure, surface morphology and optical properties of ZnO nanorods and the photocatalytic activity test for methylene blue degradation. The experimental results showed that 3% Cerium dopant has produced hexagonal morphology ZnO nanorod growing more uniform on (002) crystal planes, increased the intensity of ultraviolet absorbance thereby increase the degradation speed of methylene blue.

  13. Mechanistic studies on the formation of silver nanowires by a hydrothermal method.

    PubMed

    Tetsumoto, Takuya; Gotoh, Yasuo; Ishiwatari, Tsutomu

    2011-10-15

    Silver (Ag) nanowires were fabricated from silver chloride (AgCl) by the hydrothermal method. The successful formation of Ag nanowires relied on the low solubility of AgCl as a precursor and the structural change of glucose to polymer on the Ag nanowire (protective layer). The Ag(+) ion concentration in the reaction solution containing AgCl was initially low, but after a reaction time of over 12 h, Ag(+) gradually reduced to Ag metal. Transmission electron microscope, Raman spectrometery, and X-ray photoelectron spectroscopy revealed that the surface of the obtained Ag nanowires possessed a carbon-rich layer with a carboxyl group, and the Ag(+) ion coordinated with the carboxyl group of this layer. The difference in the surface-free energy of Ag crystals changed the crystal growth rate that impelled the anisotropic growth of the Ag particles. By examining various reaction conditions, it was determined that the ratio of Cl(-) to Ag(+), reaction temperature, and reaction time are important factors for successful preparation of Ag nanowires. Under the reaction condition that the molar ratio of Cl(-) to Ag(+) at 160 °C for 24 h is above equimolar concentration, uniform Ag nanowires were successfully prepared. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. One-step synthesis of titanium oxide nanocrystal- rutile by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Yan, Evyan Yang Chia; Zakaria, Sarani; Chia, Chin Hua

    2014-09-01

    Pure rutile phase titanium oxides (TiO2) nanocrystals were synthesized via hydrothermal method with titanium tetrachloride (TiCl4) and water (H2O) treated in an autoclave. The particle size and phase assemblages were characterized using Scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. Band gap energy (Eg) of the nanocrystals was estimated from the Ultra violet - visible light (UV-vis) absorption spectra. It was demonstrated that TiO2 nanocrystals can be prepared through increasing of temperature and period of treatment. It is believed that the presence of acid chloride (HCl) as by-product during the hydrolysis played an important role in controlling the growth of morphology and crystal structures. The Eg of the samples were estimated from the plot of modified Kubelka-Munk function were in the range of 3.04 - 3.26eV for the samples synthesized at temperature ranging from 50 to 200°C for 16 hours.

  15. Hydrazine-hydrothermal method to synthesize three-dimensional chalcogenide framework for photocatalytic hydrogen generation

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Kanhere, Pushkar D.; Ling Wong, Chui; Tian, Yuefeng; Feng, Yuhua; Boey, Freddy; Wu, Tom; Chen, Hongyu; White, Tim J.; Chen, Zhong; Zhang, Qichun

    2010-11-01

    A novel chalcogenide, [Mn 2Sb 2S 5(N 2H 4) 3] (1), has been synthesized by the hydrazine-hydrothermal method. X-ray crystallography study reveals that the new compound 1 crystallizes in space group P1¯ (no. 2) of the triclinic system. The structure features an open neutral three-dimensional framework, where two-dimensional mesh-like inorganic layers are bridged by intra- and inter-layer hydrazine ligands. Both two Mn1 and Mn2 sites adopt distorted octahedral coordination. While two Sb1 and Sb2 sites exhibit two different coordination geometries, the Sb1 site is coordinated with three S atoms to generate a SbS 3 trigonal-pyramidal geometry, and the Sb2 site adopts a SbS 4 trigonal bipyramidal coordination geometry. It has an optical band gap of about ˜2.09 eV, which was deduced from the diffuse reflectance spectrum, and displays photocatalytic behaviors under visible light irradiation. Magnetic susceptibility measurements show compound 1 obeys the Curie-Weiss law in the range of 50-300 K.

  16. Electric Properties of NaTaO3 Obtained by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Malaescu, Dan; Grozescu, Ioan; Sfirloaga, Paula; Vlazan, Paulina; Marin, Catalin N.

    2015-12-01

    Two samples of NaTaO3 perovskite materials were prepared by the standard hydrothermal method at the same reaction temperature (600 °C) but with different sintering times: 6 hours for sample S1 and 12 hours for sample S2. Using X-ray diffraction (XRD), it shows that samples S1 and S2 are mixtures of Na-Ta oxides (Ta2O5 and the prevailing phase NaTaO3). The scanning electron microscopy analysis (SEM), shows that the grains are connected each other in agglomerated clusters of size about few hundred nanometers. The frequency (f) dependencies of complex impedance, Z(f) = Z'(f) - i Z''(f) of the samples, over the frequency range 20 Hz - 2 MHz, at room temperature are presented. The real component Z' of the complex impedance decreases with increasing frequency and the imaginary component Z'' has two maximum corresponding to two relaxation processes. The results obtained from the complex impedance spectroscopy, Z''(Z') showed the appearance of two semicircles, corresponding to grain and grain boundary mechanism. Experimental results have been fitted with two parallel RC equivalent circuits connected in series and the parameters R and C have been evaluated.

  17. Shape-control by microwave-assisted hydrothermal method for the synthesis of magnetite nanoparticles using organic additives

    NASA Astrophysics Data System (ADS)

    Rizzuti, Antonino; Dassisti, Michele; Mastrorilli, Piero; Sportelli, Maria C.; Cioffi, Nicola; Picca, Rosaria A.; Agostinelli, Elisabetta; Varvaro, Gaspare; Caliandro, Rocco

    2015-10-01

    A simple and fast microwave-assisted hydrothermal method is proposed for the synthesis of magnetite nanoparticles. The addition of different surfactants (polyvinylpyrrolidone, oleic acid, or trisodium citrate) was studied to investigate the effect on size distribution, morphology, and functionalization of the magnetite nanoparticles. Microwave irradiation at 150 °C for 2 h of aqueous ferrous chloride and hydrazine without additives resulted in hexagonal magnetite nanoplatelets with a facet-to-facet distance of 116 nm and a thickness of 40 nm having a saturation magnetization of 65 Am2 kg-1. The use of polyvinylpyrrolidone led to hexagonal nanoparticles with a facet-to-facet distance of 120 nm and a thickness of 53 nm with a saturation magnetization of 54 Am2 kg-1. Additives such as oleic acid and trisodium citrate yielded quasi-spherical nanoparticles of 25 nm in size with a saturation magnetization of 70 Am2 kg-1 and spheroidal nanoparticles of 60 nm in size with a saturation magnetization up to 82 Am2 kg-1, respectively. A kinetic control of the crystal growth is believed to be responsible for the hexagonal habit of the nanoparticles obtained without additive. Conversely, a thermodynamic control of the crystal growth, leading to spheroidal nanoparticles, seems to occur when additives which strongly interact with the nanoparticle surface are used. A thorough characterization of the materials was performed. Magnetic properties were investigated by Superconducting Quantum Interference Device and Vibrating Sample magnetometers. Based on the observed magnetic properties, the magnetite obtained using citrate appears to be a promising support for magnetically transportable catalysts.

  18. Electrical and electrochemical performance of Mn{sub 3}O{sub 4} nanoparticles synthesized by hydrothermal method

    SciTech Connect

    Shaik, Dadamiah P. M. D.; Rosaiah, P.; Hussain, O. M.

    2016-05-06

    Hausmannite Mn{sub 3}O{sub 4} nanoparticles have been synthesized by a simple hydrothermal method at low temperature. The microstructural, electrical and dielectric properties were studied. The XRD data exhibited different diffraction peaks along with predominant (211) orientation corresponds to tetragonal structure of Mn{sub 3}O{sub 4} with crystallite size of 65 nm. The SEM analysis reveals that the octahedral shape of grains with average grain size of 250 nm. The vibrational studies from Raman measurements confirmed the formation of Mn{sub 3}O{sub 4}. The impedance response of the Mn{sub 3}O{sub 4} sample was studied over the frequency range of 1 Hz – 1 MHz in the temperature range from room temperature to 373 K. The conductivity of the sample was observed to be increased (1.86 × 10{sup −5} S/m at 373 K) with temperature following the Arrhenius behavior with an estimated activation energy of 0.37 eV. The dielectric constant and dielectric loss were examined from 333 K to 373 K in the frequency range of 1 Hz – 1 MHz. The electrochemical performance of Mn{sub 3}O{sub 4} electrode was examined in 1M K{sub 2}SO{sub 4} aqueous electrolyte which exhibited a high specific capacitance of 356 F/g at a scan rate of 10 mV/s over a potential range −0.1 V – +0.9 V and showed excellent electrochemical stability during cycling.

  19. A simple method for the measurement of reflective foil emissivity

    NASA Astrophysics Data System (ADS)

    Ballico, M. J.; van der Ham, E. W. M.

    2013-09-01

    Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to "bubble-wrap". Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a "primary method" and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

  20. A simple method to improve autonomous GPS positioning for tractors.

    PubMed

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory.

  1. A Simple Method to Improve Autonomous GPS Positioning for Tractors

    PubMed Central

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory. PMID:22163917

  2. A simple method for the measurement of reflective foil emissivity

    SciTech Connect

    Ballico, M. J.; Ham, E. W. M. van der

    2013-09-11

    Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to 'bubble-wrap'. Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a 'primary method' and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

  3. Synthesis of BiFeO3 thin films on single-terminated Nb : SrTiO3 (111) substrates by intermittent microwave assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Velasco-Davalos, Ivan; Ambriz-Vargas, Fabian; Kolhatkar, Gitanjali; Thomas, Reji; Ruediger, Andreas

    2016-06-01

    We report on a simple and fast procedure to create arrays of atomically flat terraces on single crystal SrTiO3 (111) substrates and the deposition of ferroelectric BiFeO3 thin films on such single-terminated surfaces. A microwave-assisted hydrothermal method in deionized water and ammonia solution selectively removes either (SrO3)4- or Ti4+ layers to ensure the same chemical termination on all terraces. Measured step heights of 0.225 nm (d111) and uniform contrast in the phase image of the terraces confirm the single termination in pure and Nb doped SrTiO3 single crystal substrates. Multiferroic BiFeO3 thin films were then deposited by the same microwave assisted hydrothermal process on Nb : SrTiO3 (111) substrates. Bi(NO3)3 and Fe(NO3)3 along with KOH served as the precursors solution. Ferroelectric behavior of the BiFeO3 films on Nb : SrTiO3 (100) substrates was verified by piezoresponse force microscopy.

  4. Hydrothermal synthesis of ytterbium silicate nanoparticles.

    PubMed

    Chen, Hongfei; Gao, Yanfeng; Liu, Yun; Luo, Hongjie

    2010-02-15

    A simple, low-cost hydrothermal method was developed to synthesize 20-nm-diameter single-crystalline ytterbium silicate (Yb(2)Si(2)O(7) and Yb(2)SiO(5)) nanoparticles at 200 degrees C. This is nearly 1000 degrees C lower than that for the typical sol-gel route to ytterbium silicate powders. Obtained powders showed very low thermal conductivity, a suitable thermal expansion coefficient, and excellent thermal/structural stability, suggesting a potential application to environmental and thermal barrier coatings. Special focus was placed on assessing the hydrothermal reaction mechanism for particle formation.

  5. One-step mild hydrothermal method to prepare low valent sodium vanadium(III) monohydrogenphosphate: NaV(HPO4)2

    NASA Astrophysics Data System (ADS)

    Abeysinghe, Dileka; Smith, Mark D.; zur Loye, Hans-Conrad

    2017-07-01

    Green colored single crystals of a reduced sodium vanadium(III) monohydrogenphosphate, NaV(HPO4)2, were grown using a one-step mild hydrothermal method. The in situ reduction of V5+ to V3+ was performed using copper acetate as the reducing agent. The title compound crystalizes in the monoclinic space group Cc and exhibits a three-dimensional crystal structure that consists of distorted VO6 octahedra connected to PO3(OH) tetrahedra that are further connected via Na cations. The compound exhibits simple paramagnetic behavior at high temperatures and a discontinuity near 5 K is likely due to the onset of magnetic coupling. The compound was also characterized by TGA, IR and UV-vis spectroscopies.

  6. Hydrothermal Processing

    SciTech Connect

    Elliott, Douglas C.

    2011-03-11

    This chapter is a contribution to a book on Thermochemical Conversion of Biomass being edited by Prof. Robert Brown of Iowa State University. It describes both hydrothermal liquefaction and hydrothermal gasification of biomass to fuels.

  7. P-doped TiO2 with superior visible-light activity prepared by rapid microwave hydrothermal method

    NASA Astrophysics Data System (ADS)

    Niu, Jinfen; Lu, Pan; Kang, Mei; Deng, Kunfa; Yao, Binghua; Yu, Xiaojiao; Zhang, Qian

    2014-11-01

    Phosphorous-doped anatase TiO2 powders (P-TiO2) were prepared by rapid microwave hydrothermal method. The resulting materials were characterized by XRD, SEM, XPS, DRS and N2 adsorption. P-doping decreased the band gap and enlarged the surface area of P-doped samples than that of undoped TiO2 samples. Therefore, the photocatalytic degradation of methyl blue (MB) and tetracycline hydrochloride (Tc) experiments showed that the P-TiO2 catalysts, especially the two-steps-controlling products P-TiO2-2, exhibited higher degradation efficiency than the undoped TiO2 and commercial P25 under visible-light irradiation. Hydroxyl radicals (rad OH) have been confirmed to be the active species during the photocatalytic oxidation reaction. The microwave hydrothermal method confirms to be very suitable for the synthesis of superior visible-light activity P-doped samples.

  8. A Simple Method for High-Lift Propeller Conceptual Design

    NASA Technical Reports Server (NTRS)

    Patterson, Michael; Borer, Nick; German, Brian

    2016-01-01

    In this paper, we present a simple method for designing propellers that are placed upstream of the leading edge of a wing in order to augment lift. Because the primary purpose of these "high-lift propellers" is to increase lift rather than produce thrust, these props are best viewed as a form of high-lift device; consequently, they should be designed differently than traditional propellers. We present a theory that describes how these props can be designed to provide a relatively uniform axial velocity increase, which is hypothesized to be advantageous for lift augmentation based on a literature survey. Computational modeling indicates that such propellers can generate the same average induced axial velocity while consuming less power and producing less thrust than conventional propeller designs. For an example problem based on specifications for NASA's Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) flight demonstrator, a propeller designed with the new method requires approximately 15% less power and produces approximately 11% less thrust than one designed for minimum induced loss. Higher-order modeling and/or wind tunnel testing are needed to verify the predicted performance.

  9. A simple capacitive method to evaluate ethanol fuel samples

    NASA Astrophysics Data System (ADS)

    Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

    2017-02-01

    Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few.

  10. A new simple multidomain fast multipole boundary element method

    NASA Astrophysics Data System (ADS)

    Huang, S.; Liu, Y. J.

    2016-09-01

    A simple multidomain fast multipole boundary element method (BEM) for solving potential problems is presented in this paper, which can be applied to solve a true multidomain problem or a large-scale single domain problem using the domain decomposition technique. In this multidomain BEM, the coefficient matrix is formed simply by assembling the coefficient matrices of each subdomain and the interface conditions between subdomains without eliminating any unknown variables on the interfaces. Compared with other conventional multidomain BEM approaches, this new approach is more efficient with the fast multipole method, regardless how the subdomains are connected. Instead of solving the linear system of equations directly, the entire coefficient matrix is partitioned and decomposed using Schur complement in this new approach. Numerical results show that the new multidomain fast multipole BEM uses fewer iterations in most cases with the iterative equation solver and less CPU time than the traditional fast multipole BEM in solving large-scale BEM models. A large-scale fuel cell model with more than 6 million elements was solved successfully on a cluster within 3 h using the new multidomain fast multipole BEM.

  11. A simple capacitive method to evaluate ethanol fuel samples

    PubMed Central

    Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

    2017-01-01

    Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few. PMID:28240312

  12. A simple calibration method for mechanically braked cycle ergometers.

    PubMed

    Van Praagh, E; Bedu, M; Roddier, P; Coudert, J

    1992-01-01

    The calibration of cycle ergometers should be checked regularly. Some studies have shown calibration errors of more than 40%. A simple, inexpensive calibrating method for mechanically braked cycle ergometers was developed and tried out on a new type of ergocycle. The cycle ergometer was elevated and the crank replaced by a pulley fitted to the shaft. The crank speed (rpm) increased linearly as a function of time when different masses were applied on the pulley. For a given braking force on the cycle ergometer, different accelerations corresponding to the increased pulley forces could be measured. When extrapolating for zero acceleration, it was possible to determine a "limit-force" which allowed the system to be in equilibrium. Additional force creates motion. The same experiments were repeated with increasing braking forces. Using the differently sized gear sprockets of the transmission system, it was possible to calculate the actual force, including all the resistances. The actual force found by the calibrating method was then compared with the indicated force proposed by the manufacturer. With increasing forces, the relative errors decreased from 9.6 to 2.9%. The cycle ergometer calibrated by this technique meets the standards recommended in exercise physiology.

  13. A simple graphical method for measuring inherent safety.

    PubMed

    Gupta, J P; Edwards, David W

    2003-11-14

    Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects.A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O'Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure. The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No

  14. Core-shell hematite nanorods: a simple method to improve the charge transfer in the photoanode for photoelectrochemical water splitting.

    PubMed

    Gurudayal; Chee, Png Mei; Boix, Pablo P; Ge, Hu; Yanan, Fang; Barber, James; Wong, Lydia Helena

    2015-04-01

    We report a simple method to produce a stable and repeatable photoanode for water splitting with a core-shell hematite (α-Fe2O3) nanorods system by combining spray pyrolysis and hydrothermal synthesis. Impedance spectroscopy revealed passivation of the surface states by the shell layer, which results in an increase of the charge injection through the hematite conduction band. In pristine hematite more holes are accumulated on the surface and the charge transfer to the electrolyte occurs through surface states, whereas in the core-shell hematite photoanode the majority of hole transfer process occurs through the valence band. As a result the photoactivity of the core-shell nanorods, 1.2 mA cm(-2), at 1.23 V vs RHE, is twice that of pristine hematite nanorods. The alteration of the interface energetics is supported by TEM, showing that the crystallinity of the surface has been improved by the deposition of the shell.

  15. Preparation of SiO2 nanowires from rice husks by hydrothermal method and the RNA purification performance

    NASA Astrophysics Data System (ADS)

    Huang, Meiyan; Cao, Jianping; Meng, Xing; Liu, Yangsi; Ke, Wei; Wang, Jialiang; Sun, Ling

    2016-10-01

    In this study, SiO2 nanowires were prepared by using rice husks as silicon source via a hydrothermal method. The microstructure, thermal stability and morphology of SiO2 nanowires were characterized by X-ray diffraction, infrared spectroscopy, thermal gravimetric analysis and scanning electron microscope. SiO2 nanowires with a diameter of 30-100 nm were obtained and the formation mechanism of SiO2 nanowires during the hydrothermal reaction was proposed. The SiO2 nanowires were introduced into membrane spin columns to isolate RNA and the values of A260/280 and A260/230 were 2.0-2.1 and 1.8-2.0, respectively, which shows the SiO2 nanowires were effective for RNA purification.

  16. Luminescence properties of BaTiO{sub 3}:Eu{sup 3+} obtained via microwave stimulated hydrothermal method

    SciTech Connect

    Pazik, R.; Wiglusz, R.J.; Strek, W.

    2009-06-03

    BaTiO{sub 3} nanocrystalline powders doped with the Eu{sup 3+} ions have been prepared using microwave stimulated hydrothermal method (MSHM). Structure, average grain size and morphology of the BaTiO{sub 3}:Eu{sup 3+} were analyzed by means of the X-ray powder diffraction measurements, Raman spectroscopy and SEM microscopy. The luminescence properties and decay times of the hydrothermal BT:Eu{sup 3+} nanocrystalline powders have been investigated as a function of the grain size, dopant concentration, preparation conditions and sintering temperature. It was found that the studied properties are strongly dependent on the grain size of BaTiO{sub 3}:Eu{sup 3+} nano-crystallites.

  17. Simple method for purification of enterotoxigenic E. coli fimbriae

    PubMed Central

    Curtis, Brittany; Grassel, Christen; Laufer, Rachel; Sears, Khandra; Pasetti, Marcela F.; Barry, Eileen M.; Simon, Raphael

    2016-01-01

    Enterotoxigenic E. coli (ETEC) are endemic pathogens in the developing world. They frequently cause illness in travelers, and are among the most prevalent causes of diarrheal disease in children. Pathogenic ETEC strains employ fimbriae as adhesion factors to bind the luminal surface of the intestinal epithelium and establish infection. Accordingly, there is marked interest in immunoprophylactic strategies targeting fimbriae to protect against ETEC infections. Multiple strategies have been reported for purification of ETEC fimbriae, however none is ideal. Purification has typically involved the use of highly virulent wild-type strains. We report here a simple and improved method to purify ETEC fimbriae, which was applied to obtain two different Class 5 fimbriae types of clinical relevance (CFA/I and CS4) expressed recombinantly in E. coli production strains. Following removal from cells by shearing, fimbriae proteins were purified by orthogonal purification steps employing ultracentrifugation, precipitation, and ion-exchange membrane chromatography. Purified fimbriae demonstrated the anticipated size and morphology by electron microscopy analysis, contained negligible levels of residual host cell proteins, nucleic acid, and endotoxin, and were recognized by convalescent human anti-sera. PMID:26581778

  18. Simple method for the synthesis of inverse patchy colloids.

    PubMed

    van Oostrum, P D J; Hejazifar, M; Niedermayer, C; Reimhult, E

    2015-06-17

    Inverse patchy colloids (IPC's) have recently been introduced as a conceptually simple model to study the phase-behavior of heterogeneously charged units. This class of patchy particles is referred to as inverse to highlight that the patches repel each other in contrast to the attractive interactions of conventional patches. IPCs demonstrate a complex interplay between attractions and repulsions that depend on their patch size and charge, their relative orientations as well as on charge of the substrate below; the resulting wide array of different types of aggregates that can be formed motivates their fabrication and use as model system. We present a novel method that does not rely on clean-room facilities and that is easily scalable to modify the surface of colloidal particles to create two polar regions with the opposite charge with respect to that of the equatorial region. The patch size is characterized by electron microscopy and fluorescently labeled to facilitate using confocal microscopy to study their phase behavior. We show that the pH can be used to tune the charges of the IPCs thus offering a tool to steer the self assembly.

  19. Simple method for the synthesis of inverse patchy colloids

    NASA Astrophysics Data System (ADS)

    van Oostrum, P. D. J.; Hejazifar, M.; Niedermayer, C.; Reimhult, E.

    2015-06-01

    Inverse patchy colloids (IPC's) have recently been introduced as a conceptually simple model to study the phase-behavior of heterogeneously charged units. This class of patchy particles is referred to as inverse to highlight that the patches repel each other in contrast to the attractive interactions of conventional patches. IPCs demonstrate a complex interplay between attractions and repulsions that depend on their patch size and charge, their relative orientations as well as on charge of the substrate below; the resulting wide array of different types of aggregates that can be formed motivates their fabrication and use as model system. We present a novel method that does not rely on clean-room facilities and that is easily scalable to modify the surface of colloidal particles to create two polar regions with the opposite charge with respect to that of the equatorial region. The patch size is characterized by electron microscopy and fluorescently labeled to facilitate using confocal microscopy to study their phase behavior. We show that the pH can be used to tune the charges of the IPCs thus offering a tool to steer the self assembly.

  20. Simple method of generating and distributing frequency-entangled qudits

    NASA Astrophysics Data System (ADS)

    Jin, Rui-Bo; Shimizu, Ryosuke; Fujiwara, Mikio; Takeoka, Masahiro; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Gerrits, Thomas; Sasaki, Masahide

    2016-11-01

    High-dimensional, frequency-entangled photonic quantum bits (qudits for d-dimension) are promising resources for quantum information processing in an optical fiber network and can also be used to improve channel capacity and security for quantum communication. However, up to now, it is still challenging to prepare high-dimensional frequency-entangled qudits in experiments, due to technical limitations. Here we propose and experimentally implement a novel method for a simple generation of frequency-entangled qudts with d\\gt 10 without the use of any spectral filters or cavities. The generated state is distributed over 15 km in total length. This scheme combines the technique of spectral engineering of biphotons generated by spontaneous parametric down-conversion and the technique of spectrally resolved Hong-Ou-Mandel interference. Our frequency-entangled qudits will enable quantum cryptographic experiments with enhanced performances. This distribution of distinct entangled frequency modes may also be useful for improved metrology, quantum remote synchronization, as well as for fundamental test of stronger violation of local realism.

  1. Simple and scalable method for peptide inhalable powder production.

    PubMed

    Schoubben, Aurélie; Blasi, Paolo; Giovagnoli, Stefano; Ricci, Maurizio; Rossi, Carlo

    2010-01-31

    The aim of this work was to produce capreomycin dry powder and capreomycin loaded PLGA microparticles intended for tuberculosis inhalation therapy, using simple and scalable methods. Capreomycin physico-chemical characteristics have been modified by hydrophobic ion pairing with oleate. The powder suspension was processed by high pressure homogenization and spray-dried. Spray-drying was also used to prepare capreomycin oleate (CO) loaded PLGA microparticles. CO powder was suspended in the organic phase containing PLGA and the suspension was spray-dried. Particle dimensions were determined using photon correlation spectroscopy and Accusizer C770. Morphology was investigated by scanning electron microscopy (SEM) and capreomycin content by spectrophotometry. Capreomycin properties were modified to increase polymeric microparticle content and obtain respirable CO powder. High pressure homogenization allowed to reduce CO particle dimensions obtaining a population in the micrometric (6.18 microm) and one in the nanometric (approximately 317 nm) range. SEM pictures showed not perfectly spherical particles with a wrinkled surface, generally suitable for inhalation. PLGA particles were characterized by a high encapsulation efficiency (about 90%) and dimensions (approximately 6.69 microm) suitable for inhalation. Concluding, two different formulations were successfully developed for capreomycin pulmonary delivery. The hydrophobic ion pair strategy led to a noticeable drug content increase.

  2. A finite volume method for fluctuating hydrodynamics of simple fluids

    NASA Astrophysics Data System (ADS)

    Narayanan, Kiran; Samtaney, Ravi; Moran, Brian

    2015-11-01

    Fluctuating hydrodynamics accounts for stochastic effects that arise at mesoscopic and macroscopic scales. We present a finite volume method for numerical solutions of the fluctuating compressible Navier Stokes equations. Case studies for simple fluids are demonstrated via the use of two different equations of state (EOS) : a perfect gas EOS, and a Lennard-Jones EOS for liquid argon developed by Johnson et al. (Mol. Phys. 1993). We extend the fourth order conservative finite volume scheme originally developed by McCorquodale and Colella (Comm. in App. Math. & Comput. Sci. 2011), to evaluate the deterministic and stochastic fluxes. The expressions for the cell-centered discretizations of the stochastic shear stress and stochastic heat flux are adopted from Espanol, P (Physica A. 1998), where the discretizations were shown to satisfy the fluctuation-dissipation theorem. A third order Runge-Kutta scheme with weights proposed by Delong et al. (Phy. Rev. E. 2013) is used for the numerical time integration. Accuracy of the proposed scheme will be demonstrated. Comparisons of the numerical solution against theory for a perfect gas as well as liquid argon will be presented. Regularizations of the stochastic fluxes in the limit of zero mesh sizes will be discussed. Supported by KAUST Baseline Research Funds.

  3. Transformation of Morinda citrifolia via simple mature seed imbibition method.

    PubMed

    Lee, J J; Ahmad, S; Roslan, H A

    2013-12-15

    Morinda citrifolia, is a valuable medicinal plant with a wide range of therapeutic properties and extensive transformation study on this plant has yet been known. Present study was conducted to establish a simple and reliable transformation protocol for M. citrifolia utilising Agrobacterium tumefaciens via direct seed exposure. In this study, the seeds were processed by tips clipping and dried and subsequently incubated in inoculation medium. Four different parameters during the incubation such as incubation period, bacterial density, temperature and binary vectors harbouring beta-glucuronidase (GUS) gene (pBI121 and pGSA1131), were tested to examine its effect on transformation efficiency. The leaves from the treated and germinated seedlings were analysed via Polymerase Chain Reaction (PCR), histochemical assay of the GUS gene and reverse transcription-PCR (RT-PCR). Results of the study showed that Agrobacterium strain LBA4404 with optical density of 1.0 and 2 h incubation period were optimum for M. citrifolia transformation. It was found that various co-cultivation temperatures tested and type of vector used did not affect the transformation efficiency. The highest transformation efficiency for M. citrifolia direct seed transformation harbouring pBI121 and pGSA1131 was determined to be 96.8% with 2 h co-cultivation treatment and 80.4% when using bacterial density of 1.0, respectively. The transformation method can be applied for future characterization study of M. citrifolia.

  4. A simple method for identification of irradiated spices

    NASA Astrophysics Data System (ADS)

    Behere, Arun; Desai, S. R. Padwal; Rao, S. M. D.; Nair, P. M.

    Thermoluminescence (TL) properties of curry powder, a salt containing spice mixture, and three different ground spices, viz. chilli, turmeric and pepper, were compared with TL of table salt. The spices other than curry powder, did not exhibit characteristic TL in the absence of salt. Therefore studies were initiated to develop a simple and reliable method using common salt for distinguishing irradiated spices (10 kGy) from unirradiated ones under normal conditions of storage. Common salt exhibited a characteristic TL glow at 170°C. However, when present in curry powder, the TL glow of salt showed a shift to 208°C. It was further observed that upon storage up to 6 months, the TL of irradiated curry powder retained about 10% of the original intensity and still could be distinguished from the untreated samples. From our results it is evident that common salt could be used as an indicator either internally or externally in small sachets for incorporating into prepacked spices.

  5. Simple method for purification of enterotoxigenic Escherichia coli fimbriae.

    PubMed

    Curtis, Brittany; Grassel, Christen; Laufer, Rachel S; Sears, Khandra T; Pasetti, Marcela F; Barry, Eileen M; Simon, Raphael

    2016-03-01

    Enterotoxigenic Escherichia coli (ETEC) are endemic pathogens in the developing world. They frequently cause illness in travelers, and are among the most prevalent causes of diarrheal disease in children. Pathogenic ETEC strains employ fimbriae as adhesion factors to bind the luminal surface of the intestinal epithelium and establish infection. Accordingly, there is marked interest in immunoprophylactic strategies targeting fimbriae to protect against ETEC infections. Multiple strategies have been reported for purification of ETEC fimbriae, however none is ideal. Purification has typically involved the use of highly virulent wild-type strains. We report here a simple and improved method to purify ETEC fimbriae, which was applied to obtain two different Class 5 fimbriae types of clinical relevance (CFA/I and CS4) expressed recombinantly in E. coli production strains. Following removal from cells by shearing, fimbriae proteins were purified by orthogonal purification steps employing ultracentrifugation, precipitation, and ion-exchange membrane chromatography. Purified fimbriae demonstrated the anticipated size and morphology by electron microscopy analysis, contained negligible levels of residual host cell proteins, nucleic acid, and endotoxin, and were recognized by convalescent human anti-sera.

  6. Synthesis of bilayer MoS{sub 2} nanosheets by a facile hydrothermal method and their methyl orange adsorption capacity

    SciTech Connect

    Ye, Lijuan; Xu, Haiyan; Zhang, Dingke; Chen, Shijian

    2014-07-01

    Highlights: • Hexagonal phase of MoS{sub 2} nanosheets was synthesized by a facile hydrothermal method. • FE-SEM and TEM images show the sheets-like morphology of MoS{sub 2}. • Bilayer MoS{sub 2} can be grown under the optimized mole ratio of 2:1 of S:Mo at 180 °C for 50 h. • The MoS{sub 2} nanosheets possess high methyl orange adsorption capacity due to the large surface area. - Abstract: Molybdenum disulfide (MoS{sub 2}) nanosheets have received significant attention recently due to the potential applications for exciting physics and technology. Here we show that MoS{sub 2} nanosheets can be prepared by a facile hydrothermal method. The study of the properties of the MoS{sub 2} nanosheets prepared at different conditions suggests that the mole ratio of precursors and hydrothermal time significantly influences the purity, crystalline quality and thermal stability of MoS{sub 2}. X-ray diffraction, Raman spectra and transmission electron microscopy results indicate that bilayer MoS{sub 2} can be grown under an optimized mole ratio of 2:1 of S:Mo at 180 °C for 50 h. Moreover, such ultrathin nanosheets exhibit a prominent photoluminescence and possess high methyl orange adsorption capacity due to the large surface area, which can be potentially used in photodevice and photochemical catalyst.

  7. Preparation of Co3O4 Nanostructures via a Hydrothermal- Assisted Thermal Treatment Method by Using of New Precursors

    NASA Astrophysics Data System (ADS)

    Gholamrezaei, Sousan; Salavati-Niasari, Masoud; Hadadzadeh, Hassan; Behnamfar, Mohammad Taghi

    2017-02-01

    Co3O4 nanostructures have been synthesized via a hydrothermal-assisted thermal treatment process. A new complex formulated as [Co(py)2(H2O)2(NO3)2] was synthesized, and then used to prepare Co3O4 nanostructures. Cubic phase of spinel Co3O4 nanostructures with particle size of about 39 nm could be produced after calcination of the Co(OH)2 materials prepared with hydrothermal method at 160 °C for 15 h. Using of inorganic precursors decreased the time and temperature of Co3O4 preparation. The effect of pH on the morphology of the product s synthesized by hydrothermal reactions was investigated. It was found that the best morphology was achieved on pH=8, where was not prepared any precipitation. In this method, we could decrease the reaction temperature in synthetic rout to fabricate Co3O4 nanostructures. Nanostructures were characterized by SEM, TEM, X-ray diffraction (XRD), UV-visible, Fourier transformed infrared (FT-IR) spectroscopy and Nuclear magnetic resonance (1H-NMR).

  8. Systematic study on surface and magnetostructural changes in Mn-substituted dysprosium ferrite by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Rekha, G.; Tholkappiyan, R.; Vishista, K.; Hamed, Fathalla

    2016-11-01

    Dysprosium iron garnets are of scientific importance because of the wide range of magnetic properties that can be obtained in substituting dysprosium by a rare earth metal. In the present work, the effect of Mn substitution on magnetostructural changes in dysprosium ferrite nanoparticles is studied. Highly crystalline pure and Mn doped dysprosium ferrite nanoparticles were synthesized by hydrothermal method. The samples were calcined at 1100 °C for 2 h in air atmosphere which is followed by characterization using XRD, FT-IR analysis, SEM, XPS and VSM. The average crystallite size of synthesized samples were calculated by X-ray diffraction falls in the range of 88.4-86.8 nm and was found to be in cubic garnet structure. For further investigation of the structure and corresponding changes in the tetrahedral and octahedral stretching vibrational bonds, FT-IR was used. The synthesized samples consist of multiple oxidation (Fe3+ and Fe2+) states for Fe ions and (Mn3+ and Mn2+) Mn ions analyzed in three ways of Fe 2p and Mn 2p spectra from the XPS analysis. With respect to Mn dopant in Dy3Fe5O12, the cationic distributions of elements were discussed from high resolution XPS spectra by peak position and shift, area, width. To find out the porous/void surface morphology of the sample, scanning electron microscopy was used. From XPS analysis, the presence of elements (Dy, Mn, Fe and O) and their composition in the prepared samples were confirmed. Further, the role of dopant on the magnetic properties of the dysprosium ferrite nanoparticles was also observed from VSM which shows the ferromagnetic behavior. It was concluded that the magnetic properties of synthesized nanoparticles mainly depended on the oxidation state of elements, cationic distribution and crystallinity.

  9. Characterization of ZnO:Co particles prepared by hydrothermal method for room temperature magnetism

    NASA Astrophysics Data System (ADS)

    Peng, Yingzi; Huo, Dexuan; He, Haiping; Li, Yuan; Li, Lingwei; Wang, Huawen; Qian, Zhenghong

    2012-03-01

    ZnO based diluted magnetic semiconductor particles (ZnO:Co) have been grown using a hydrothermal method with good crystallinity. The atomic percentage of Co presented in the specimen is about 0.01. Based on the x-ray diffraction and high-resolution transition electron, Co is found to be incorporated into ZnO lattice without evidence of obvious Co precipitates. However, from photoluminescence (PL) spectra in the range of 1.94 -3.45 eV, a strong broad emission centered around 600 nm (2.07 eV) in the visible range as well as a relatively weak peak at 2.81 eV are observed, indicating the presence of Co impurities. Moreover, intrinsic emissions such as DOX suggest that at least some Co have been doped into ZnO lattice, substituting for Zn2+ ions. The PL results further confirm the substitution of Zn2+ ions by Co, which leads to the changes of the electronic band structures. Magnetism could be realized at room temperature for the ZnO:Co nanoparticles under our experimental conditions although with low coercivity. The field-cooled and zero-field-cooled curves can be explained as a result of competition between the ferromagnetic and the antiferromagnetic ordering in the ZnO:Co nanoparticles. Combining the results from PL and magnetism characterization, it is reasonable to think that both doped Co in the ZnO lattice and Co impurities contribute to magnetism in ZnO:Co nanoparticles at room temperature.

  10. Simple method of isolating humic acids from organic soils

    NASA Astrophysics Data System (ADS)

    Ahmed, O.

    2009-04-01

    Humic substances particularly humic acids (HA) play a major role in soil conditioning e.g. erosion control, soil cation exchange capacity, complexation of heavy metal ions and pesticides, carbon and nitrogen cycles, plant growth and reduction of ammonia volatilization from urea. Humified substances such as coal, composts, and peat soils have substantial amounts of HA but the isolation of these acids is expensive, laborious, and time consuming. Factors that affect the quality and yield of HA isolated from these materials include extraction, fractionation, and purification periods. This work developed a simple, rapid, and cost effective method of isolating HA from peat soils. There was a quadratic relationship between extraction period and HA yield. Optimum extraction period was estimated at 4 h instead of the usual range of 12 to 48 h. There was no relationship between fractionation period and HA yield. As such 2 h instead of the usual range of 12 to 24 h fractionation period could be considered optimum. Low ash content (5%), remarkable reduction in K, coupled with the fact that organic C, E4/E6, carboxylic COOH, phenolic OH, and total acidity values of the HA were consistent with those reported by other authors suggest that the HA dealt with were free from mineral matter. This was possible because the distilled water used to purify the HA served as Bronsted-Lowry acid during the purification process of the HA. Optimum purification period using distilled waster was 1 h instead of the usual range of 1 and 7 days (uses HF and HCl and dialysis). Humic acids could be isolated from tropical peat soils within 7 h (i.e. 4 h extraction, 2 h fractionation, and 1 h purification) instead of the existing period of 2 and 7 days. This could facilitate the idea of producing organic fertilizers such as ammonium-humate and potassium-humate from humified substances since techniques devised in this study did not alter the true nature of the HA. Besides, the technique is rapid, simple

  11. Simple method of isolating humic acids from organic soils

    NASA Astrophysics Data System (ADS)

    Ahmed, O. H.; Susilawati, K.; Nik Muhamad, A. B.; Khanif, M. Y.

    2009-04-01

    Humic substances particularly humic acids (HA) play a major role in soil conditioning e.g. erosion control, soil cation exchange capacity, complexation of heavy metal ions and pesticides, carbon and nitrogen cycles, plant growth and reduction of ammonia volatilization from urea. Humified substances such as coal, composts, and peat soils have substantial amounts of HA but the isolation of these acids is expensive, laborious, and time consuming. Factors that affect the quality and yield of HA isolated from these materials include extraction, fractionation, and purification periods. This work developed a simple, rapid, and cost effective method of isolating HA from peat soils. There was a quadratic relationship between extraction period and HA yield. Optimum extraction period was estimated at 4 h instead of the usual range of 12 to 48 h. There was no relationship between fractionation period and HA yield. As such 2 h instead of the usual range of 12 to 24 h fractionation period could be considered optimum. Low ash content (5%), remarkable reduction in K, coupled with the fact that organic C, E4/E6, carboxylic COOH, phenolic OH, and total acidity values of the HA were consistent with those reported by other authors suggest that the HA dealt with were free from mineral matter. This was possible because the distilled water used to purify the HA served as Bronsted-Lowry acid during the purification process of the HA. Optimum purification period using distilled waster was 1 h instead of the usual range of 1 and 7 days (uses HF and HCl and dialysis). Humic acids could be isolated from tropical peat soils within 7 h (i.e. 4 h extraction, 2 h fractionation, and 1 h purification) instead of the existing period of 2 and 7 days. This could facilitate the idea of producing organic fertilizers such as ammonium-humate and potassium-humate from humified substances since techniques devised in this study did not alter the true nature of the HA. Besides, the technique is rapid, simple

  12. Nanocrystalline spinel ferrite (MFe{sub 2}O{sub 4}, M = Ni, Co, Mn, Mg, Zn) powders prepared by a simple aloe vera plant-extracted solution hydrothermal route

    SciTech Connect

    Phumying, Santi; Labuayai, Sarawuth; Swatsitang, Ekaphan; Amornkitbamrung, Vittaya; Maensiri, Santi

    2013-06-01

    Graphical abstract: This figure shows the specific magnetization curves of the as-prepared MFe{sub 2}O{sub 4} (M = Ni, Co, Mn, Mg, Zn) powders obtained from room temperature VSM measurement. These curves are typical for a soft magnetic material and indicate hysteresis ferromagnetism in the field ranges of ±500 Oe, ±1000 Oe, and ±2000 Oe for the CoFe{sub 2}O{sub 4}, MgFe{sub 2}O{sub 4} and MnFe{sub 2}O{sub 4} respectively, whereas the samples of NiFe{sub 2}O{sub 4} and ZnFe{sub 2}O{sub 4} show a superparamagnetic behavior. Highlights: ► Nanocrystalline MFe{sub 2}O{sub 4} powders were synthesized by a novel hydrothermal method. ► Metal acetylacetonates and aloe vera plant-extracted solution are used. ► This biosynthetic route is very simple and provides high-yield oxide nanomaterials. ► XRD and TEM results indicate that the prepared samples have only spinel structure. ► The maximum M{sub s} of 68.9 emu/g at 10 kOe were observed for the samples of MnFe{sub 2}O{sub 4}. - Abstract: Nanocrystalline spinel ferrite MFe{sub 2}O{sub 4} (M = Ni, Co, Mn, Mg, Zn) powders were synthesized by a novel hydrothermal method using Fe(acac){sub 3}, M(acac){sub 3} (M = Ni, Co, Mn, Mg, Zn) and aloe vera plant extracted solution. The X-ray diffraction and selected-area electron diffraction results indicate that the synthesized nanocrystalline have only spinel structure without the presence of other phase impurities. The crystal structure and morphology of the spinel ferrite powders, as revealed by TEM, show that the NiFe{sub 2}O{sub 4} and CoFe{sub 2}O{sub 4} samples contain nanoparticles, whereas the MnFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4} samples consist of many nanoplatelets and nanoparticles. Interestingly, the ZnFe{sub 2}O{sub 4} sample contains plate-like structure of networked nanocrystalline particles. Room temperature magnetization results show a ferromagnetic behavior of the CoFe{sub 2}O{sub 4}, MnFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4} samples, whereas the

  13. A Simple, Powerful Method for Optimal Guidance of Spacecraft Formations

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.

    2006-01-01

    One of the most interesting and challenging aspects of formation guidance law design is the coupling of the orbit design and the science return. The analyst's role is more complicated than simply to design the formation geometry and evolution. He or she is also involved in designing a significant portion of the science instrument itself. The effectiveness of the formation as a science instrument is intimately coupled with the relative geometry and evolution of the collection of spacecraft. Therefore, the science return can be maximized by optimizing the orbit design according to a performance metric relevant to the science mission goals. In this work, we present a simple method for optimal formation guidance that is applicable to missions whose performance metric, requirements, and constraints can be cast as functions that are explicitly dependent upon the orbit states and spacecraft relative positions and velocities. We present a general form for the cost and constraint functions, and derive their semi-analytic gradients with respect to the formation initial conditions. The gradients are broken down into two types. The first type are gradients of the mission specific performance metric with respect to formation geometry. The second type are derivatives of the formation geometry with respect to the orbit initial conditions. The fact that these two types of derivatives appear separately allows us to derive and implement a general framework that requires minimal modification to be applied to different missions or mission phases. To illustrate the applicability of the approach, we conclude with applications to two missions: the Magnetospheric Multiscale mission (MMS) , and the Laser Interferometer Space Antenna (LISA).

  14. A Simple, Powerful Method for Optimal Guidance of Spacecraft Formations

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.

    2005-01-01

    One of the most interesting and challenging aspects of formation guidance law design is the coupling of the orbit design and the science return. The analyst s role is more complicated than simply to design the formation geometry and evolution. He or she is also involved in designing a significant portion of the science instrument itself. The effectiveness of the formation as a science instrument is intimately coupled with the relative geoniet,ry and evolution of the collection of spacecraft. Therefore, the science return can be maximized by optimizing the orbit design according to a performance metric relevant to the science mission goals. In this work, we present a simple method for optimal formation guidance that is applicable to missions whose performance metric, requirements, and constraints can be cast as functions that are explicitly dependent upon the orbit states and spacecraft relative positions and velocities. We present a general form for the cost and constraint functions, and derive their semi-analytic gradients with respect to the formation initial conditions. The gradients are broken down into two types. The first type are gradients of the mission specific performance metric with respect to formation geometry. The second type are derivatives of the formation geometry with respect to the orbit initial conditions. The fact that these two types of derivatives appear separately allows us to derive and implement a general framework that requires minimal modification to be applied to different missions or mission phases. To illustrate the applicability of the approach, we conclude with applications to twc missims: the Magnetospheric Mu!tiscale mission (MMS), a,nd the TJaser Interferometer Space Antenna (LISA).

  15. A simple objective method for determining a dynamic journal collection.

    PubMed

    Bastille, J D; Mankin, C J

    1980-10-01

    In order to determine the content of a journal collection responsive to both user needs and space and dollar constraints, quantitative measures of the use of a 647-title collection have been related to space and cost requirements to develop objective criteria for a dynamic collection for the Treadwell Library at the Massachusetts General Hospital, a large medical research center. Data were collected for one calendar year (1977) and stored with the elements for each title's profile in a computerized file. To account for the effect of the bulk of the journal runs on the number of uses, raw use data have been adjusted using linear shelf space required for each title to produce a factor called density of use. Titles have been ranked by raw use and by density of use with space and cost requirements for each. Data have also been analyzed for five special categories of use. Given automated means of collecting and storing data, use measures should be collected continuously. Using raw use frequency ranking to relate use to space and costs seems sensible since a decision point cutoff can be chosen in terms of the potential interlibrary loans generated. But it places new titles at risk while protecting titles with long, little used runs. Basing decisions on density of use frequency ranking seems to produce a larger yield of titles with fewer potential interlibrary loans and to identify titles with overlong runs which may be pruned or converted to microform. The method developed is simple and practical. Its design will be improved to apply to data collected in 1980 for a continuous study of journal use. The problem addressed is essentially one of inventory control. Viewed as such it makes good financial sense to measure use as part of the routine operation of the library to provide information for effective management decisions.

  16. Evaluating the indoor and outdoor environment: using a simple method.

    PubMed

    Fikry, Mohga M; Mortada, Mona M; Nosseir, Samia A; Reda, Aida A; Hussein, Ahmed H; Abdel-Gawad, Ensaf S

    2005-01-01

    Housing is the conjunction of the dwelling, the home, the immediate environment and the community. Between 1960 and 1980, the urban population in developing countries more than doubled and is expected to reach 56% of the total population by the year 2025. In many cities, the development of squatter settlements and shanty towns had grown rapidly causing the destruction of green areas. The number of people living in urban slums and shanty towns is an indicator of conditions in the cities and the United Nations had estimated that about one-third of urban dwellers in developing countries live in such settlements. Poverty is highly prevalent among the residents of these areas. Outdoor environmental degradation, together with the social degradation affects the health of the urban population especially the poor causing a burden of ill-health, disability, poor indoor housing, and high maternal and infant mortality. The aim of the present study is to evaluate the indoor and outdoor environment using a simple method and to assess its reliability and validity. The scoring system, which was developed for the assessment of the indoor and outdoor environmental levels included 36 items (18 for the indoor and 18 for the outdoor) using a questionnaire. Results revealed that the proposed scoring system was able to reveal significance difference between served (water, electricity, and sewerage system were available) and unserved areas when using t-test, z-test, and chi-square testing. The proposed scoring system was reliable and valid especially in indoor assessment. Outdoor scores might need more modifications to improve its reliability.

  17. A simple field method to determine mercury volatilization from soils.

    PubMed

    Böhme, Frank; Rinklebe, Jörg; Stärk, Hans-Joachim; Wennrich, Rainer; Mothes, Sibylle; Neue, Heinz-Ulrich

    2005-01-01

    Estimations of gaseous mercury volatilization from soils are often complex, stationary and expensive. Our objective was to develop a mobile and more simple, easy to handle and more cost-effective field method allowing rapid estimates of potential Hg emissions from soils. The study site is located in Germany, about 100 kilometers south-westerly of Berlin and influenced by the river Elbe and its tributary Saale river. The site is representative for a lot of other floodplain locations at the river Elbe and highly polluted with Hg and other heavy metals. For our study we developed a system consisting of a glass chamber gas, two gold traps, a battery operated pump and a gas meter. Adsorbed total gaseous mercury (TGM) in the gold traps was determined by use of atomic absorption spectrometry (AAS). In contrast to the common used flux chambers we designed a chamber without inlet and named it gas suck up chamber (GSC). TGM fluxes determined with the GSC showed a very close linear correlation (r = 0.993) between the TGM content in the gold traps and the corresponding pumped gas volume. The TGM adsorbed, increased proportional with increasing gas volume indicating homogenous concentrations of gaseous mercury in the soil air sucked. In contrast to the commonly used dynamic flux chamber with the aim of precisely measuring actual fluxes of Hg from a defined soil area, we focused on developing of a measurement system which will allow rapid estimates of potential Hg emissions of a site. Earlier research at the study site indicated a high potential for releasing volatile Hg from the soil to the atmosphere. Indeed, due to the high Hg content of the soil significant amounts of TGM could be detected and no shortage was reached. Our initial measurements are still too few in number neither to generalize the achieved results nor discuss controlling factors and processes. However, we are pleased to communicate that the developed GSC is well suited to become an effective sampling set up to

  18. A Simple Method for Automated Equilibration Detection in Molecular Simulations.

    PubMed

    Chodera, John D

    2016-04-12

    Molecular simulations intended to compute equilibrium properties are often initiated from configurations that are highly atypical of equilibrium samples, a practice which can generate a distinct initial transient in mechanical observables computed from the simulation trajectory. Traditional practice in simulation data analysis recommends this initial portion be discarded to equilibration, but no simple, general, and automated procedure for this process exists. Here, we suggest a conceptually simple automated procedure that does not make strict assumptions about the distribution of the observable of interest in which the equilibration time is chosen to maximize the number of effectively uncorrelated samples in the production timespan used to compute equilibrium averages. We present a simple Python reference implementation of this procedure and demonstrate its utility on typical molecular simulation data.

  19. A Novel Method for Discovering Fuzzy Sequential Patterns Using the Simple Fuzzy Partition Method.

    ERIC Educational Resources Information Center

    Chen, Ruey-Shun; Hu, Yi-Chung

    2003-01-01

    Discusses sequential patterns, data mining, knowledge acquisition, and fuzzy sequential patterns described by natural language. Proposes a fuzzy data mining technique to discover fuzzy sequential patterns by using the simple partition method which allows the linguistic interpretation of each fuzzy set to be easily obtained. (Author/LRW)

  20. A Novel Method for Discovering Fuzzy Sequential Patterns Using the Simple Fuzzy Partition Method.

    ERIC Educational Resources Information Center

    Chen, Ruey-Shun; Hu, Yi-Chung

    2003-01-01

    Discusses sequential patterns, data mining, knowledge acquisition, and fuzzy sequential patterns described by natural language. Proposes a fuzzy data mining technique to discover fuzzy sequential patterns by using the simple partition method which allows the linguistic interpretation of each fuzzy set to be easily obtained. (Author/LRW)

  1. Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

    NASA Technical Reports Server (NTRS)

    Leif, Roald N.; Simoneit, Bernd R. T.

    1995-01-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  2. Large Marks-decahedral Pd nanoparticles synthesized by a modified hydrothermal method using a homogeneous reactor

    NASA Astrophysics Data System (ADS)

    Zhao, Haiqiang; Qi, Weihong; Ji, Wenhai; Wang, Tianran; Peng, Hongcheng; Wang, Qi; Jia, Yanlin; He, Jieting

    2017-05-01

    Fivefold symmetry appears only in small particles and quasicrystals because internal stress in the particles increases with the particle size. However, a typical Marks decahedron with five re-entrant grooves located at the ends of the twin boundaries can further reduce the strain energy. During hydrothermal synthesis, it is difficult to stir the reaction solution contained in a digestion high-pressure tank because of the relatively small size and high-temperature and high-pressure sealed environment. In this work, we optimized a hydrothermal reaction system by replacing the conventional drying oven with a homogeneous reactor to shift the original static reaction solution into a full mixing state. Large Marks-decahedral Pd nanoparticles ( 90 nm) have been successfully synthesized in the optimized hydrothermal synthesis system. Additionally, in the products, round Marks-decahedral Pd particles were also found for the first time. While it remains a challenge to understand the growth mechanism of the fivefold twinned structure, we proposed a plausible growth-mediated mechanism for Marks-decahedral Pd nanoparticles based on observations of the synthesis process.

  3. Confined-pyrolysis as an experimental method for hydrothermal organic synthesis

    NASA Astrophysics Data System (ADS)

    Leif, Roald N.; Simoneit, Bernd R. T.

    1995-10-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic compounds and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  4. Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

    NASA Technical Reports Server (NTRS)

    Leif, Roald N.; Simoneit, Bernd R. T.

    1995-01-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  5. Confined-pyrolysis as an experimental method for hydrothermal organic synthesis.

    PubMed

    Leif, R N; Simoneit, B R

    1995-10-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic compounds and competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  6. A Simple Method for Tracking Vertebrate-Dispersed Seeds

    SciTech Connect

    Levey, D.J.; Sargent, S.

    1999-01-20

    New and simple technique for tracking seeds using fluorescence microspheres applied to fruit and later recovered in fecal material of captive Cedar Waxwings. Study demonstrates high percentage recovery of microspheres, all defecations having seeds have microspheres, few microspheres recovered in defecations not having seeds and presence of microspheres on fruit does not affect fruit choice.

  7. Simple method for monitoring rangeland health and wildlife habitat

    USDA-ARS?s Scientific Manuscript database

    We describe a monitoring system that requires just a pencil, one page datasheet and a 1-meter stick. Data are collected using the stick at five locations on each of four 25-m transects. Vegetation cover, composition, and horizontal and vertical structure are recorded by marking simple icons on the s...

  8. Simple Methods of Calculating Dispersion from Urban Area Sources.

    ERIC Educational Resources Information Center

    Hanna, Steven R.

    A simple but physically realistic model is shown to be adequate for estimating long-term average pollutant concentrations due to area sources in cities. In this model, the surface concentration is directly proportional to the local area source strength and inversely proportional to the wind speed. The model performs nearly as well as much more…

  9. Improving Student Engagement in Mathematics Using Simple but Effective Methods

    ERIC Educational Resources Information Center

    Shearman, Donald; Rylands, Leanne; Coady, Carmel

    2012-01-01

    A significant proportion of students enrolling in mathematical subjects designed for non-STEM majors in university courses have minimal mathematical skills and poor motivation. This combination of starting attributes often leads to failure in the first mathematical subject encountered. We have been implementing simple, alternative pedagogies in an…

  10. A modified Bogoliubov method applied to a simple boson model

    NASA Astrophysics Data System (ADS)

    Litt, O.; Bassichis, W. H.

    2017-01-01

    We use a non-gauge-invariant modification of the exact Hamiltonian to obtain a new Hamiltonian-like operator for a simple exactly solvable boson model. The eigenvalues of the new operator are close to those of the original Hamiltonian. We make a one-body approximation of the new two-body operator in the spirit of the Bogoliubov approximation. Because only the number operator appears, the c-number approximation is not required individually for the creation or annihilation operators in the ground state. For the simple model, the results using the new approximation are closer to the exact results than the usual Bogoliubov results over a wide range of parameters. The improvement increases dramatically as the model interaction strength increases.

  11. Simple and Rapid Method for Detecting Biofilm Forming Bacteria.

    PubMed

    Kalia, Vipin Chandra; Prakash, Jyotsana; Koul, Shikha; Ray, Subhasree

    2017-03-01

    Biofilm forming bacteria play a vital role in causing infectious diseases and for enhancing the efficiency of the bioremediation process through immobilization. Different media and conditions have been reported for detecting biofilm forming bacteria, however, they are not quite rapid. Here, we propose the use of a simple medium which can be used for detecting biofilm former, and also provide a mechanism to regulate the expression of biofilm formation process.

  12. A simple method for producing flattened atomic force microscopy tips.

    PubMed

    Biagioni, P; Farahani, J N; Mühlschlegel, P; Eisler, H-J; Pohl, D W; Hecht, B

    2008-01-01

    We describe a simple and reliable procedure for obtaining a flat plateau on top of standard silicon nitride atomic force microscopy tips by scanning them over the focus of a high-numerical-aperture objective illuminated by near-infrared ultrashort laser pulses. Flattened tips produced this way exhibit a plateau that is parallel to the substrate when the cantilever is mounted. They represent a valid and cost-effective alternative to commercially available plateau tips.

  13. Hydrothermal Synthesis, Structure, and Superconductivity of Simple Cubic Perovskite (Ba0.62K0.38)(Bi0.92Mg0.08)O3 with Tc ∼ 30 K.

    PubMed

    Rubel, Mirza H K; Takei, Takahiro; Kumada, Nobuhiro; Ali, M Mozahar; Miura, Akira; Tadanaga, Kiyoharu; Oka, Kengo; Azuma, Masaki; Magome, Eisuke; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

    2017-03-20

    We have synthesized a new superconducting perovskite bismuth oxide by a facile hydrothermal route at 220 °C. The choice of starting materials, their mixing ratios, and the hydrothermal reaction temperature was crucial for obtaining products with superior superconducting properties. The structure of the powder sample was investigated using laboratory X-ray diffraction, high-resolution synchrotron X-ray diffraction (SXRD) data, and electron diffraction (ED) patterns [transmission electron microscopy (TEM) analysis]. The refinement of SXRD data confirmed a simple perovskite-type structure with a cubic cell of a = 4.27864(2) Å [space group Pm3̅m (No. 221)]. Elemental analysis detected magnesium in the final products, and a refinement based on SXRD and inductively coupled plasma data yielded an ideal undistorted simple cubic perovskite-type structure, with the chemical composition (Ba0.62K0.38)(Bi0.92Mg0.08)O3. ED patterns also confirmed the simple cubic perovskite structure; the cube-shaped microstructures and compositional homogeneity on the nanoscale were verified by scanning electron microscopy and TEM analyses, respectively. The fabricated compound exhibited a large shielding volume fraction of about 98% with a maximum Tc(mag) of ∼30 K, which was supported by the measured bismuth valence as well. Its electrical resistivity dropped at ∼21 K, and zero resistivity was observed below 7 K. The compound underwent thermal decomposition above 400 °C. Finally, the calculated band structure showed a metallic behavior for this hydrothermally synthesized bismuth oxide.

  14. The effect of annealing on properties of europium doped ZnO nanopowders obtained by a microwave hydrothermal method

    NASA Astrophysics Data System (ADS)

    Wolska-Kornio, E.; Kaszewski, J.; Witkowski, B. S.; Wachnicki, Ł.; Godlewski, M.

    2016-09-01

    Europium doped ZnO nanopowders made by microwave hydrothermal method are investigated. As zinc oxide precursor zinc nitrate(V) hexahydrate (Zn(NO3)2·6H2O) was used. Two types of nanopowder samples are examined: as grown and annealed at 750 °C in air atmosphere. We investigate the structural, morphological and optical prosperities of europium doped ZnO. Results of scanning electron microscopy, X-ray diffraction, photo- and cathodoluminescence investigations and also CIE1961 chromaticity diagram are presented.

  15. Pathways for synthesis of new selenium-containing oxo-compounds: Chemical vapor transport reactions, hydrothermal techniques and evaporation method

    NASA Astrophysics Data System (ADS)

    Kovrugin, Vadim M.; Colmont, Marie; Siidra, Oleg I.; Gurzhiy, Vladislav V.; Krivovichev, Sergey V.; Mentré, Olivier

    2017-01-01

    Due to the low and close melting and sublimation temperatures (340 and 350 °C, respectively), the crystal growth of selenates and/or selenites is generally achieved using either chemical vapor transport routes, hydrothermal methods due to the good solubility and reactivity of (SeO3)2- anions or isothermal evaporation synthesis. Here we report examples many new crystal structures obtained using these synthesis routes. Particularly, description of each process is given with theoretical and practical information assorted with description of selected structures.

  16. Mimicking natural fibrous structures of opals by means of a microemulsion-mediated hydrothermal method.

    PubMed

    Hassan, Natalia; Verdinelli, Valeria; Ruso, Juan M; Messina, Paula V

    2011-07-19

    Silica-based nanomaterials are of great interest because of their potential applications in constructing electronic and optoelectronic nanodevices. Especially significant are those that combine the properties of photonic crystal with a fibrous semiconductor structure. Here we report the use of microemulsion droplet systems as a simple and controllable route for the synthesis of 3D opals materials with an unusual fibrous microstructure similar to those that exist in nature. By this method, we demonstrate the creation of very long fibrils of 30-50 nm diameter and more than 20 μm length showing simultaneous short and long wavelength light emissions and band gap values (5.50 and 4.41 eV) comparable to those obtained for silicon-based metal oxide semiconductors.

  17. Properties of beryl single crystals grown by a high pressure hydrothermal method

    SciTech Connect

    Furusaki, T.; Bando, Y.; Kodaira, K. ); Matsushita, T. )

    1989-08-01

    The authors discuss beryl crystals grown under high pressure hydrothermal condition of 1 GPa. The optimum crystal growth was observed at 600{sup 0}C and from 0.1N NaOH solution. The beryl crystals from 0.1 - 0.3N NaOH solutions incorporated water molecules and alkali cations in the channels of the beryl structure. The crystals showed same refractive indices and density as those of natural emerald crystals. These physical properties were very similar to natural emeralds.

  18. Novel hydrothermal method for effective doping of N and F into nano Titania for both, energy and environmental applications

    SciTech Connect

    Jyothi, M.S.; D’Souza Laveena, P.; Shwetharani, R.; Balakrishna, Geetha R.

    2016-02-15

    Highlights: • Novel method to synthesize N, F doped TiO{sub 2} via hydrothermal method is discussed. • Change in bandgap of TiO{sub 2} upon doping makes a photocatalyst visible active. • 94% of degradation of EtBr was achieved within a less time of 90 min. • The doped titania also showed good efficiency as photo anodic material for solar cell. - Abstract: A novel and an efficient hydrothermal method for the preparation of an effective doped titania photocatalyst is reported. The crystal phase, binding energy, elemental composition, morphology, optical and electronic structure analyses were done by various techniques. The doped titania proved as an efficient electrode material and photocatalyst for solar cells and water treatment respectively. The photocatalyst is able to degrade the most potent mutagen ethidium bromide under sunlight with an enhancement of 1.6 times over its undoped analogue. As photo-anode material, showed an improved open circuit potential and fill factor. The created electron states in the doped sample act as charge carrier traps suppressing recombination which later detraps the same to the surface of the catalyst causing enhanced interfacial charge transfer. Surface acidity caused by F induction and lowered band gap energy that can respond to visible light facilitates improved energy harvesting and energy transfer leading to better photo activity.

  19. A simple approximation method for obtaining the spanwise lift distribution

    NASA Technical Reports Server (NTRS)

    Schrenk, O

    1940-01-01

    The approximation method described makes possible lift-distribution computations in a few minutes. Comparison with an exact method shows satisfactory agreement. The method is of greater applicability than the exact method and includes also the important case of the wing with end plates.

  20. Simple methods for the 3' biotinylation of RNA.

    PubMed

    Moritz, Bodo; Wahle, Elmar

    2014-03-01

    Biotinylation of RNA allows its tight coupling to streptavidin and is thus useful for many types of experiments, e.g., pull-downs. Here we describe three simple techniques for biotinylating the 3' ends of RNA molecules generated by chemical or enzymatic synthesis. First, extension with either the Schizosaccharomyces pombe noncanonical poly(A) polymerase Cid1 or Escherichia coli poly(A) polymerase and N6-biotin-ATP is simple, efficient, and generally applicable independently of the 3'-end sequences of the RNA molecule to be labeled. However, depending on the enzyme and the reaction conditions, several or many biotinylated nucleotides are incorporated. Second, conditions are reported under which splint-dependent ligation by T4 DNA ligase can be used to join biotinylated and, presumably, other chemically modified DNA oligonucleotides to RNA 3' ends even if these are heterogeneous as is typical for products of enzymatic synthesis. Third, we describe the use of 29 DNA polymerase for a template-directed fill-in reaction that uses biotin-dUTP and, thanks to the enzyme's proofreading activity, can cope with more extended 3' heterogeneities.

  1. Co3O4-ZnO hierarchical nanostructures by electrospinning and hydrothermal methods

    NASA Astrophysics Data System (ADS)

    Kanjwal, Muzafar A.; Sheikh, Faheem A.; Barakat, Nasser A. M.; Chronakis, Ioannis S.; Kim, Hak Yong

    2011-07-01

    A new hierarchical nanostructure that consists of cobalt oxide (Co3O4) and zinc oxide (ZnO) was produced by the electrospinning process followed by a hydrothermal technique. First, electrospinning of a colloidal solution that consisted of zinc nanoparticles, cobalt acetate tetrahydrate and poly(vinyl alcohol) was performed to produce polymeric nanofibers embedding solid nanoparticles. Calcination of the obtained electrospun nanofiber mats in air at 600 °C for 1 h, produced Co3O4 nanofibers with rough surfaces containing ZnO nanoparticles (i.e., ZnO-doped Co3O4 nanofibers). The rough surfaced nanofibers, containing ZnO nanoparticles (ZnNPs), were then exploited as seeds to produce ZnO nanobranches using a specific hydrothermal technique. Scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to characterize the as-spun nanofibers and the calcined product. X-ray powder diffractometery (XRD) analysis was used to study the chemical composition and the crystallographic structure.

  2. Relatively simple, precise methods to analyze temperature transients in ectotherms.

    PubMed

    Voss, M A.; Reed Hainsworth, F

    2001-04-01

    Relatively complex core-shell models have been used to precisely characterize times and temperatures for ectotherms. There is a simpler method using a second-order analysis of heat flux. We derive the method from an equivalent mechanical system, correct some previously published inaccuracies, and show how to use the method by analyzing thermal transients for House Wren eggs under natural conditions.

  3. Synthesis and photocatalytic activity for water-splitting reaction of nanocrystalline mesoporous titania prepared by hydrothermal method

    SciTech Connect

    Jitputti, Jaturong; Pavasupree, Sorapong; Suzuki, Yoshikazu; Yoshikawa, Susumu

    2007-05-15

    Nanocrystalline mesoporous TiO{sub 2} was synthesized by hydrothermal method using titanium butoxide as starting material. XRD, SEM, and TEM analyses revealed that the synthesized TiO{sub 2} had anatase structure with crystalline size of about 8 nm. Moreover, the synthesized titania possessed a narrow pore size distribution with average pore diameter and high specific surface area of 215 m{sup 2}/g. The photocatalytic activity of synthesized TiO{sub 2} was evaluated with photocatalytic H{sub 2} production from water-splitting reaction. The photocatalytic activity of synthesized TiO{sub 2} treated with appropriate calcination temperature was considerably higher than that of commercial TiO{sub 2} (Ishihara ST-01). The utilization of mesoporous TiO{sub 2} photocatalyst with high crystallinity of anatase phase promoted great H{sub 2} production. Furthermore, the reaction temperature significantly influences the water-splitting reaction. - Graphical abstract: Nanocrystalline mesoporous TiO{sub 2} was synthesized by hydrothermal method. The physical properties of the synthesized TiO{sub 2} were thoroughly studied in relation to its photocatalytic activity for H{sub 2} evolution from water-splitting reaction. It was found that the photocatalytic activity of synthesized TiO{sub 2} treated with appropriate calcination temperature was considerably higher than that of commercial TiO{sub 2} (Ishihara ST-01)

  4. Synthesis of zinc aluminate with high surface area by microwave hydrothermal method applied in the transesterification of soybean oil (biodiesel)

    SciTech Connect

    Quirino, M.R.; Oliveira, M.J.C.; Keyson, D.; Lucena, G.L.; Oliveira, J.B.L.; Gama, L.

    2016-02-15

    Highlights: • ZnAl{sub 2}O{sub 4} spinel was synthesized by the microwave hydrothermal method in only 15 or 30 min. • The powders show high specific surface area. • ZAT{sub b}15 showed activity of 52.22% for the conversion of soybean oil into biodiesel. - Abstract: Zinc aluminate is a material with high thermal stability and high mechanical strength that, owing to these properties, is used as a catalyst or support. In this work, zinc aluminate spinel was synthesized by the microwave hydrothermal method in only 15 or 30 min at a low temperature (150 °C) without templates, using only Al(NO{sub 3}){sub 3}·9H{sub 2}O, Zn(NO{sub 3}){sub 2}·6H{sub 2}O, and urea as precursors and applied in the transesterification of soybean oil. X-ray diffraction analysis showed that ZnAl{sub 2}O{sub 4} had a cubic structure without secondary phases. The nitrogen adsorption measurements (BET) revealed a high surface area (266.57 m{sup 2} g{sup −1}) for the nanopowder synthesized in 15 min. This powder showed activity of 52.22% for the catalytic conversion of soybean oil into biodiesel by transesterification.

  5. A simple method to evaluate the reliability of OWAS observations.

    PubMed

    de Bruijn, I; Engels, J A; van der Gulden, J W

    1998-08-01

    Slides showing nurses in different working postures were used to determine the reliability of OWAS observations. Each slide could be looked at for 3 seconds, while a new slide was shown every 30 seconds to resemble the normal practice of observation. Two observers twice scored a series of slides, some of them being identical at both viewings. To reduce effects of recall there was a time interval of 4 weeks or more between the two viewings and the slides were in a different order the second time. Different series were used to evaluate inter- and intra-observer reliability. The OWAS scores of corresponding slides were compared. In almost all comparisons percentages of agreement over 85% and kappa's over 0.6 were found, which is considered as good agreement. The procedure described seems to be a useful and simple technique to determine such reliability.

  6. Simple method for calibrating omnidirectional stereo with multiple cameras

    NASA Astrophysics Data System (ADS)

    Ha, Jong-Eun; Choi, I.-Sak

    2011-04-01

    Cameras can give useful information for the autonomous navigation of a mobile robot. Typically, one or two cameras are used for this task. Recently, an omnidirectional stereo vision system that can cover the whole surrounding environment of a mobile robot is adopted. They usually adopt a mirror that cannot offer uniform spatial resolution. In this paper, we deal with an omnidirectional stereo system which consists of eight cameras where each two vertical cameras constitute one stereo system. Camera calibration is the first necessary step to obtain 3D information. Calibration using a planar pattern requires many images acquired under different poses so it is a tedious step to calibrate all eight cameras. In this paper, we present a simple calibration procedure using a cubic-type calibration structure that surrounds the omnidirectional stereo system. We can calibrate all the cameras on an omnidirectional stereo system in just one shot.

  7. Simple, rapid method for the preparation of isotopically labeled formaldehyde

    SciTech Connect

    Hooker, Jacob Matthew; Schonberger, Matthias; Schieferstein, Hanno; Fowler, Joanna S.

    2011-10-04

    Isotopically labeled formaldehyde (*C.sup..sctn.H.sub.2O) is prepared from labeled methyl iodide (*C.sup..sctn.H.sub.3I) by reaction with an oxygen nucleophile having a pendant leaving group. The mild and efficient reaction conditions result in good yields of *C.sup..sctn.H.sub.2O with little or no *C isotopic dilution. The simple, efficient production of .sup.11CH.sub.2O is described. The use of the .sup.11CH.sub.2O for the formation of positron emission tomography tracer compounds is described. The reaction can be incorporated into automated equipment available to radiochemistry laboratories. The isotopically labeled formaldehyde can be used in a variety of reactions to provide radiotracer compounds for imaging studies as well as for scintillation counting and autoradiography.

  8. Estimating cut points: A simple method for new wearables.

    PubMed

    Hickey, A; Newham, J; Slawinska, M M; Kwasnicka, D; McDonald, S; Del Din, S; Sniehotta, F F; Davis, P A; Godfrey, A

    2016-01-01

    Wearable technology is readily available for continuous assessment due to a growing number of commercial devices with increased data capture capabilities. However, many commercial devices fail to support suitable parameters (cut points) derived from the literature to help quantify physical activity (PA) due to differences in manufacturing. A simple metric to estimate cut points for new wearables is needed to aid data analysis. The purpose of this pilot study was to investigate a simple methodology to determine cut points based on ratios between sedentary behaviour (SB) and PA intensities for a new wrist worn device (PRO-Diary™) by comparing its output to a validated and well characterised 'gold standard' (ActiGraph™). Twelve participants completed a semi-structured (four-phase) treadmill protocol encompassing SB and three PA intensity levels (light, moderate, vigorous). The outputs of the devices were compared accounting for relative intensity. Count ratios (6.31, 7.68, 4.63, 3.96) were calculated to successfully determine cut-points for the new wrist worn wearable technology during SB (0-426) as well as light (427-803), moderate (804-2085) and vigorous (≥ 2086) activities, respectively. Our findings should be utilised as a primary reference for investigations seeking to use new (wrist worn) wearable technology similar to that used here (i.e., PRO-Diary™) for the purposes of quantifying SB and PA intensities. The utility of count ratios may be useful in comparing devices or SB/PA values estimated across different studies. However, a more robust examination is required for different devices, attachment locations and on larger/diverse cohorts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. A simple enzymatic method for examining calcite ossicles of Echinodermata.

    PubMed

    Tiago, C G; Brites, A D; Kawauchi, G Y

    2005-06-01

    The various shapes, size and fine details of ossicles are of paramount importance as systematic characters in the Echinodermata. The ossicles in this group are endodermal and a method to free them from the dermis is essential for their study. To date, a small quantity of hypochlorite solution (usually household liquid bleach) has been used to dissolve a small piece of tissue and, consequently, free these ossicles. A new method, using a proteolytic enzyme instead of hypochlorite solution to dissolve holothurian tissues, is proposed. This method was tested on fragments of body tissues from three species in three different orders of holothurians: Holothuria grisea Selenka, 1867 (Aspidochirotida), Duasmodactyla seguroensis (Deichmann, 1930) (Dendrochirotida) and Synaptula secreta Ancona Lopez (1957) (Apodida). Observations of material prepared using the hypochlorite and the enzyme methods were made using scanning electron microscopy (SEM). The SEM images show the striking differences in the surface of the ossicles obtained by each method, and reveal the advantages of the enzyme method.

  10. A Simple Method for Determining Specific Yield from Pumping Tests

    USGS Publications Warehouse

    Ramsahoye, L.E.; Lang, Solomon Max

    1961-01-01

    A simpler solution which greatly reduces the time necessary to compute the specific yield by the pumping-test method of Remson and Lang (1955) is presented. The method consists of computing the volume of dewatered material in the cone of depression and comparing it with the total volume of discharged water. The original method entails the use of a slowly converging series to compute the volume of dewatered material. The solution given herein is derived directly from Darcy's law.

  11. Simple numerical method for predicting steady compressible flows

    NASA Technical Reports Server (NTRS)

    Vonlavante, Ernst; Nelson, N. Duane

    1986-01-01

    A numerical method for solving the isenthalpic form of the governing equations for compressible viscous and inviscid flows was developed. The method was based on the concept of flux vector splitting in its implicit form. The method was tested on several demanding inviscid and viscous configurations. Two different forms of the implicit operator were investigated. The time marching to steady state was accelerated by the implementation of the multigrid procedure. Its various forms very effectively increased the rate of convergence of the present scheme. High quality steady state results were obtained in most of the test cases; these required only short computational times due to the relative efficiency of the basic method.

  12. A simple vitrification method for cryobanking avian testicular tissue

    USDA-ARS?s Scientific Manuscript database

    Cryopreservation of testicular tissue is a promising method of preserving male reproductive potential for avian species. This study was conducted to assess whether a vitrification method can be used to preserve avian testicular tissue, using the Japanese quail (Coturnix japonica) as a model. A sim...

  13. Measuring Plant Water Status: A Simple Method for Investigative Laboratories.

    ERIC Educational Resources Information Center

    Mansfield, Donald H.; Anderson, Jay E.

    1980-01-01

    Describes a method suitable for quantitative studies of plant water status conducted by high school or college students and the calculation of the relative water content (RWC) of a plant. Materials, methods, procedures, and results are discussed, with sample data figures provided. (CS)

  14. Measuring Plant Water Status: A Simple Method for Investigative Laboratories.

    ERIC Educational Resources Information Center

    Mansfield, Donald H.; Anderson, Jay E.

    1980-01-01

    Describes a method suitable for quantitative studies of plant water status conducted by high school or college students and the calculation of the relative water content (RWC) of a plant. Materials, methods, procedures, and results are discussed, with sample data figures provided. (CS)

  15. A Simple and Accurate Method for Measuring Enzyme Activity.

    ERIC Educational Resources Information Center

    Yip, Din-Yan

    1997-01-01

    Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

  16. A Simple and Accurate Method for Measuring Enzyme Activity.

    ERIC Educational Resources Information Center

    Yip, Din-Yan

    1997-01-01

    Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

  17. Predicting the past: a simple reverse stand table projection method

    Treesearch

    Quang V. Cao; Shanna M. McCarty

    2006-01-01

    A stand table gives number of trees in each diameter class. Future stand tables can be predicted from current stand tables using a stand table projection method. In the simplest form of this method, a future stand table can be expressed as the product of a matrix of transitional proportions (based on diameter growth rates) and a vector of the current stand table. There...

  18. A simple method for synthesizing and producing guitar sounds

    NASA Astrophysics Data System (ADS)

    Torres, Jesús A.; Rendón, Pablo L.

    2013-05-01

    An uncomplicated model is proposed to describe the transverse force exerted by a plucked string on a guitar bridge. This model incorporates the effect of internal damping, lending the synthesized sound a transient quality that makes it more realistic than sound produced without taking damping into account. The synthesized signals are then compared to actual measurements for both free and palm-muted vibrations, and show agreement in both cases. These synthesized signals can also be used to play MIDI files through a guitar acting as a modified loudspeaker cone, driving the instrument mechanically. The sound thus obtained is realistic and provides an interesting classroom exercise for an undergraduate audience. The main set-up is also affordable as a laboratory activity and for public demonstrations, and has the advantage of being simple to implement and flexible enough to allow different kinds of modification. It is, in fact, reliable enough to use as a tool for the comparison of different guitars driven in the same manner.

  19. A simple and efficient DNA isolation method for Salvia officinalis.

    PubMed

    Aleksić, Jelena M; Stojanović, Danilo; Banović, Bojana; Jančić, Radiša

    2012-12-01

    We report an efficient, simple, and cost-effective protocol for the isolation of genomic DNA from an aromatic medicinal plant, common sage (Salvia officinalis L.). Our modification of the standard CTAB protocol includes two polyphenol adsorbents (PVP 10 and activated charcoal), high NaCl concentrations (4 M) for removing polysaccharides, and repeated Sevag treatment to remove proteins and other carbohydrate contaminants. The mean DNA yield obtained with our Protocol 2 was 330.6 μg DNA g(-1) of dry leaf tissue, and the absorbance ratios 260/280 and 260/230 nm averaged 1.909 and 1.894, respectively, revealing lack of contamination. PCR amplifications of one nuclear (26S rDNA) and one chloroplast (rps16-trnK) locus indicated that our DNA isolation protocol may be used in common sage and other aromatic and medicinal plants containing essential oil for molecular biologic and biotechnological studies and for population genetics, phylogeographic, and conservation surveys in which nuclear or chloroplast genomes would be studied in large numbers of individuals.

  20. Characterization and adsorption performance of Pb(II) on CuO nanorods synthesized by the hydrothermal method

    SciTech Connect

    Arfaoui, Lobna; Kouass, Salah; Dhaouadi, Hassouna; Jebali, Raouf; Touati, Fathi

    2015-10-15

    Highlights: • The nanorods of CuO were synthesized by a hydrothermal route without any surfactant. • X-ray diffraction showed monoclinic structure with space group C{sub 2/c}. • The nanorods show relatively high adsorption capacity for the removal of Pb(II). • The adsorption kinetics could be fitted well by the pseudo-second-order model. • The equilibrium data can be fitted well using the Langmuir isotherm model - Abstract: Copper oxide (CuO) nanorods were synthesized by hydrothermal method. The detailed structural, compositional and optical characterization of this material was also evaluated with XRD, FT-IR, EDS, and UV–vis spectroscopy, which confirmed that the obtained nanorods are well-crystallized CuO and possess good optical properties. SEM and TEM studies revealed that the as-synthesized CuO nanorods are uniform with an average diameter of 17 nm. The adsorption activity of the CuO nanostructures was studied. The adsorption results showed that the CuO nanorods are an effective and efficient adsorbent for the removal of Pb(II) ions. The influence of various operational parameters such as the pH of the solution, the contact time and the initial concentrations were also studied and the results were discussed. The estimated maximum lead ion adsorption capacity of the CuO nanorods was found to be 188.67 mg g{sup −1} at an optimum pH of 6.

  1. Preparation of perpendicular oriented TiO2 films via hydrothermal method: phase selection and growth control

    NASA Astrophysics Data System (ADS)

    Gao, Yun; Guo, Meilan; Xia, Xiaohong; Shao, Guosheng

    2013-03-01

    Either rutile or anatase vertical orientated TiO2 array films were synthesized successfully on FTO (F: SnO2) substrate via hydrothermal method through controlling the concentration of Cl- and SO42- . The density of nanorods can be adjusted by varying the volume ratio of ethanol/water, and the degree of orientation and crystallinity of TiO2 nanofilms were enhanced with increasing dosage of ethanol. Meanwhile, completely dense anatase films with [004] oriented growth appear within a very narrow concentration window when adding sulfuric acid into precursor. Besides, other alcohols such as methanol, n-propanol and n-butyl were also used as solvent to examine the role of alcohol type during hydrothermal process for both two phase films. The growth rate and degree of perpendicular orientation declined as the alkyl length of solvents increases. Hydrogen sensing characteristics of dense films of both rutile and anatase phases showed that there was a remarkable improvement of sensitivity response over reported data. It was found that rutile films have higher sensitivity while anatase films have faster response. This work is supported by Ministry of Education of China (211108) and Science and Technology of Wuhan (2010CDA024, 201110821251).

  2. Simple method to make asymptotic series of Feynman diagrams converge.

    PubMed

    Meurice, Y

    2002-04-08

    We show that, for two nontrivial lambda phi(4) problems (the anharmonic oscillator and the Landau-Ginzburg hierarchical model), improved perturbative series can be obtained by cutting off the large field contributions. The modified series converge to values exponentially close to the exact ones. For lambda larger than some critical value, the method outperforms Padé's approximants and Borel summations. The method can also be used for series which are not Borel summable such as the double-well potential series. We show that semiclassical methods can be used to calculate the modified Feynman rules, estimate the error, and optimize the field cutoff.

  3. Simple numerical method for solving the steady Euler equations

    NASA Technical Reports Server (NTRS)

    Von Lavante, E.; Melson, N. Duane

    1987-01-01

    A numerical method for solving the isenthalpic form of the governing equations for compressible inviscid flows is developed. The method is based on the concept of flux vector splitting in its implicit form and is tested on several demanding configurations. Time marching to steady state is accelerated by the implementation of the multigrid procedure which very effectively increases the rate of convergence. Steady-state results are obtained for various test cases. Only short computational times are required due to the relative efficiency of the basic method.

  4. Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

    DOEpatents

    Elliott, Douglas C; Oyler, James R

    2014-11-04

    Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

  5. Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

    DOEpatents

    Elliott, Douglas C; Oyler, James

    2013-12-17

    Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

  6. Controlled synthesis of cadmium carbonate nanowires, nanoribbons, nanorings and sphere like architectures via hydrothermal method

    SciTech Connect

    Ashoka, S.; Nagaraju, G.; Thipperudraiah, K.V.; Chandrappa, G.T.

    2010-11-15

    Crystalline nanowires, nanoribbons, nanorings and sphere like architectures of cadmium carbonate have been synthesized with the spontaneous self-assembly of nanocrystals in aqueous solution under hydrothermal condition. The powder X-ray diffraction (PXRD) patterns of these materials exhibit phase pure hexagonal structure. The perfect circular nanorings with radius 375-437 nm, as a new member of nanostructured cadmium carbonate family are being reported for the first time. The width of the cadmium carbonate nanowires/nanoribbons and nanorings, respectively are found to be in the range 11-30 and 26-50 nm as observed by transmission electron microscope (TEM). The effect of temperature and concentration of urea on the cadmium carbonate morphology is discussed. The plausible growth mechanism for the formation of nanorings is also proposed.

  7. Effect of reaction temperature on carbon films prepared by a hydrothermal electrochemical method

    NASA Astrophysics Data System (ADS)

    Tao, Y.; Yi, D.; Zhu, B.

    2012-03-01

    Carbon films were synthesized under hydrothermal electrochemical conditions using sugar as the carbon source at temperature ranging from 170 °C to 180 °C. The reaction temperature affects the degree of sugar decomposition, the concentration of carbon ions, supersaturation and overpotential of the solution, thereby affecting the morphology, orientation, and crystallinity of the films. The graphitic content (sp2) increases with increasing the processing temperature and vice versa. The higher the synthesizing temperature the less the amount of amorphous carbon (sp3). The graphite in thin films prepared at 170 °C and 175 °C shows a (101) preferred orientation, whereas those prepared at 180 °C show a fairly random orientation. The mechanism of this synthesizing process seems to consist of three stages.

  8. A simple analytical method to obtain achromatic waveplate retarders

    NASA Astrophysics Data System (ADS)

    Vilas, Jose Luis; Lazarova-Lazarova, Aleksandra

    2017-04-01

    A new linear and analytical method to design achromatic retarders using waveplates is proposed. The root of this procedure is a generalization of the Hariharan method, which supposes a set of waveplates with fast axes aligned. Hence, it imposes a set of contour conditions over the overall retardation with the aim of determining the thicknesses of the waveplates. Our method proposes a polynomial approximation of the birefringences, thus removing the contour condition. Analytic expressions for calculating the thicknesses of the waveplates are then derived, showing a non-explicit dependence on the wavelength. Moreover, the overall retardation obtained by this method is close to the optimal retardation curve achieved by minimizing the merit function of the achromatism degree.

  9. Simple methods to reduce patient exposure during scoliosis radiography

    SciTech Connect

    Butler, P.F.; Thomas, A.W.; Thompson, W.E.; Wollerton, M.A.; Rachlin, J.A.

    1986-05-01

    Radiation exposure to the breasts of adolescent females can be reduced significantly through the use of one or all of the following methods: fast, rare-earth screen-film combinations; specially designed compensating filters; and breast shielding. The importance of exposure reduction during scoliosis radiography as well as further details on the above described methods are discussed. In addition, the early results of a Center for Devices and Radiological Health study, which recorded exposure and technique data for scoliosis radiography, is presented.

  10. A simple method for labeling CT images with respiratory states

    SciTech Connect

    Berlinger, Kajetan; Sauer, Otto; Vences, Lucia; Roth, Michael

    2006-09-15

    A method is described for labeling CT images with their respiratory state by a needle, connected to the patient's chest/abdomen. By means of a leverage the needle follows the abdominal respiratory motion. The needle is visible as a blurred spot in every CT slice. The method was tested with nine patients. A series of volume scans during free breathing was performed. The detected positions of the moving needle in every single slice were compared to each other thus enabling respiratory state assignment. The tool is an inexpensive alternative to complex respiratory measuring tools for four dimensional (4D) CT and was greatly accepted in the clinic due to its simplicity.

  11. Choosing antenna aimpoints during occultations - A simple method for Galileo

    NASA Technical Reports Server (NTRS)

    Wolf, Aron A.

    1988-01-01

    Attempts have been made to design the trajectory of the Galileo orbiter so that it passes behind Jupiter, as viewed from earth, as many times as possible during the mission. During this type of pass, or occultation, the thick Jovian atmosphere acts as a lens, refracting a portion of the radio signal from the spacecraft toward earth. A method for calculating antenna aiming vectors during occultations is presented. This method meets the necessary accuracy requirements while offering a reduction in terms of complexity and usage of computer resources.

  12. A simple method avoiding non-uniqueness in the boundary element method for acoustic scattering problem.

    PubMed

    Hirosawa, Kunikazu; Ishizuka, Takashi; Fujiwara, Kyoji

    2009-05-01

    The boundary element method (BEM) is widely used for sound field analysis problems; however, it has a non-uniqueness problem in the exterior domain. Various methods to avoid this problem have been developed; however, these are not easily applied to the BEM. In this paper, a simple method called the "ICA-Ring (inner cavity ringing) method" is proposed for avoiding the non-uniqueness problem, and this method is applied to the BEM in both single and plural domains. The concept of the ICA-Ring method is that a scatterer in free space is hollowed as a shell and the volume is smaller; the eigenfrequencies are shifted to a higher range. Next, the mechanism of the non-uniqueness problem in plural domains and a reason of the application of the ICA-Ring method to the case of plural domains are explained. Finally, some results calculated by the BEM using the ICA-Ring method are shown. The calculational condition is that a cylinder with radius 0.125 m floats in two-dimensional free space. In this case, no calculational errors exist in 1-6000 Hz in both single and plural domains, when the thickness of the shell is 20 mm. The ICA-Ring method does not need to modify an existing computer program of conventional BEM.

  13. A Simple and Universal Method for Making up Buffer Solutions.

    ERIC Educational Resources Information Center

    Dennison, Clive

    1988-01-01

    Uses a method which involves weighing out an amount of the appropriate weak acid or base and dissolving it in distilled water close to the final volume. Solution is then titrated with strong acid or base to give the desired pH. Provides three examples. (MVL)

  14. A SIMPLE METHOD FOR EVALUATING DATA FROM AN INTERLABORATORY STUDY

    EPA Science Inventory

    Large-scale laboratory-and method-performance studies involving more than about 30 laboratories may be evaluated by calculating the HORRAT ratio for each test sample (HORRAT=[experimentally found among-laboratories relative standard deviation] divided by [relative standard deviat...

  15. Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics.

    PubMed

    Isobe, Gaku; Maeda, Takafumi; Bornmann, Peter; Hemsel, Tobias; Morita, Takeshi

    2014-02-01

    (K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders.

  16. A Simple Outline of Methods for Protein Isolation and Purification.

    PubMed

    Lee, Chang Hun

    2017-03-01

    At the summer workshop of the Korean Endocrine Society held in 2016, some examples of protein experiments were discussed in the session entitled "All about working with proteins." In contrast to what the title suggested, it was unrealistic to comprehensively discuss all protein analytical methods. Therefore, the goal was to outline protein experimental techniques that are useful in research or in bench work. In conversations with clinicians, however, I have always felt that researchers who do not engage in bench science have different demands than those who do. Protein research tools that are useful in bench science may not be very useful or effective in the diagnostic field. In this paper, I provide a general summary of the protein analytical methods that are used in basic scientific research, and describe how they can be applied in the diagnostic field.

  17. Simple method for prediction of aircraft noise contours

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.; Carson, T. M.

    1980-01-01

    A method for generating noise contours more rapidly and more simply than previously used programs is discussed. The method gives the area, the noise contour, and its extremities for an arbitrarily complex flight path for both takeoffs and landings with relative ease. The analysis reveals the fundamental nature of the contours and how the various factors that influence its size and shape enter into the analysis. It is noted that the effects of ground attenuation and shielding are omitted as they are important only on the initial portion of flight and are highly dependent upon aircraft configuration. However, the analysis shows that these effects could be included. It is emphasized the the single-event contour is an obvious choice for purposes of minimizing noise impact.

  18. A method of solving simple harmonic oscillator Schroedinger equation

    NASA Technical Reports Server (NTRS)

    Maury, Juan Carlos F.

    1995-01-01

    A usual step in solving totally Schrodinger equation is to try first the case when dimensionless position independent variable w is large. In this case the Harmonic Oscillator equation takes the form (d(exp 2)/dw(exp 2) - w(exp 2))F = 0, and following W.K.B. method, it gives the intermediate corresponding solution F = exp(-w(exp 2)/2), which actually satisfies exactly another equation, (d(exp 2)/dw(exp 2) + 1 - w(exp 2))F = 0. We apply a different method, useful in anharmonic oscillator equations, similar to that of Rampal and Datta, and although it is slightly more complicated however it is also more general and systematic.

  19. Simple method for detection of mutations causing hereditary fructose intolerance.

    PubMed

    Kullberg-Lindh, C; Hannoun, C; Lindh, M

    2002-11-01

    Aldolase B is critical for sugar metabolism, and a catalytic deficiency due to mutations in its gene may result in hereditary fructose intolerance (HFI) syndrome, with hypoglycaemia and severe abdominal symptoms. This report describes two cases of HFI, which were identified by intravenous fructose tolerance test and a new RFLP (restriction fragment length polymorphism) test that detects the two most common mutations, A149P and A174D. The method includes PCR of a 224-base-pair segment of exon 5, a subsequent 3 h incubation with Cac8I and agarose electrophoresis, which reveals either or both of the mutations in one single reaction. The method might be useful for screening of these mutations, which may account for more than 70% of the mutations causing HFI.

  20. A Simple Outline of Methods for Protein Isolation and Purification

    PubMed Central

    2017-01-01

    At the summer workshop of the Korean Endocrine Society held in 2016, some examples of protein experiments were discussed in the session entitled “All about working with proteins.” In contrast to what the title suggested, it was unrealistic to comprehensively discuss all protein analytical methods. Therefore, the goal was to outline protein experimental techniques that are useful in research or in bench work. In conversations with clinicians, however, I have always felt that researchers who do not engage in bench science have different demands than those who do. Protein research tools that are useful in bench science may not be very useful or effective in the diagnostic field. In this paper, I provide a general summary of the protein analytical methods that are used in basic scientific research, and describe how they can be applied in the diagnostic field. PMID:28256117

  1. Gresens 92: A simple macintosh program of the gresens method

    NASA Astrophysics Data System (ADS)

    Potdevin, Jean-Luc

    1993-10-01

    The Gresens method allows quantitative study of the volume change and the mass transfer of chemical components in rocks during alteration processes. This method has been programmed in Think Pascal (version 3.02) for Macintosh microcomputers. The program compares the densities and the chemical analyses of the original and the altered rock and calculates volume change and the gains and losses of oxides or elements (major and trace) when any chemical component is assumed immobile during alteration. It plots composition-volume diagrams and isocon diagrams that allow a reference frame to be selected for mass-balance calculations. Results can be stored in Tab-Text-Files and MacPaint files that can be accessed with spreadsheet, word processor, or graphic software.

  2. A simple, rapid method for HPLC analysis of lycopene isomers.

    PubMed

    Ishida, B K; Ma, J; Chan, B

    2001-01-01

    A rapid method for the extraction, separation and quantification of the geometric isomers of lycopene and beta-carotene from tomato fruit is described. Carotenoids in tomato were separated and eluted using a reversed-phase HPLC with a C30 column and a mobile phase consisting of methyl-t-butyl ether, methanol and ethyl acetate. The system provided sharp resolution of cis- and trans-isomers of lycopene within approximately 23 min in contrast to the longer and more complex gradient procedures required by previously described methods. Experiments indicate that the stability of extracts of fresh tomato may be improved if stored at -20 degrees C, and that the presence of the antioxidant BHA has no apparent effect on stability.

  3. A simple method of predicting S-wave velocity

    USGS Publications Warehouse

    Lee, M.W.

    2006-01-01

    Prediction of shear-wave velocity plays an important role in seismic modeling, amplitude analysis with offset, and other exploration applications. This paper presents a method for predicting S-wave velocity from the P-wave velocity on the basis of the moduli of dry rock. Elastic velocities of water-saturated sediments at low frequencies can be predicted from the moduli of dry rock by using Gassmann's equation; hence, if the moduli of dry rock can be estimated from P-wave velocities, then S-wave velocities easily can be predicted from the moduli. Dry rock bulk modulus can be related to the shear modulus through a compaction constant. The numerical results indicate that the predicted S-wave velocities for consolidated and unconsolidated sediments agree well with measured velocities if differential pressure is greater than approximately 5 MPa. An advantage of this method is that there are no adjustable parameters to be chosen, such as the pore-aspect ratios required in some other methods. The predicted S-wave velocity depends only on the measured P-wave velocity and porosity. ?? 2006 Society of Exploration Geophysicists.

  4. An Adaptive Kalman Filter Using a Simple Residual Tuning Method

    NASA Technical Reports Server (NTRS)

    Harman, Richard R.

    1999-01-01

    One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. A. H. Jazwinski developed a specialized version of this technique for estimation of process noise. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

  5. An Adaptive Kalman Filter using a Simple Residual Tuning Method

    NASA Technical Reports Server (NTRS)

    Harman, Richard R.

    1999-01-01

    One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

  6. An Adaptive Kalman Filter using a Simple Residual Tuning Method

    NASA Technical Reports Server (NTRS)

    Harman, Richard R.

    1999-01-01

    One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

  7. An Adaptive Kalman Filter Using a Simple Residual Tuning Method

    NASA Technical Reports Server (NTRS)

    Harman, Richard R.

    1999-01-01

    One difficulty in using Kalman filters in real world situations is the selection of the correct process noise, measurement noise, and initial state estimate and covariance. These parameters are commonly referred to as tuning parameters. Multiple methods have been developed to estimate these parameters. Most of those methods such as maximum likelihood, subspace, and observer Kalman Identification require extensive offline processing and are not suitable for real time processing. One technique, which is suitable for real time processing, is the residual tuning method. Any mismodeling of the filter tuning parameters will result in a non-white sequence for the filter measurement residuals. The residual tuning technique uses this information to estimate corrections to those tuning parameters. The actual implementation results in a set of sequential equations that run in parallel with the Kalman filter. A. H. Jazwinski developed a specialized version of this technique for estimation of process noise. Equations for the estimation of the measurement noise have also been developed. These algorithms are used to estimate the process noise and measurement noise for the Wide Field Infrared Explorer star tracker and gyro.

  8. A Simple Optical Coherence Tomography Quantification Method for Choroidal Neovascularization

    PubMed Central

    Sulaiman, Rania S.; Quigley, Judith; Qi, Xiaoping; O'Hare, Michael N.; Grant, Maria B.; Boulton, Michael E.

    2015-01-01

    Abstract Purpose: Therapeutic efficacy is routinely assessed by measurement of lesion size using flatmounted choroids and confocal microscopy in the laser-induced choroidal neovascularization (L-CNV) rodent model. We investigated whether optical coherence tomography (OCT) quantification, using an ellipsoid volume measurement, was comparable to standard ex vivo evaluation methods for this model and whether this approach could be used to monitor treatment-related lesion changes. Methods: Bruch's membrane was ruptured by argon laser in the dilated eyes of C57BL/6J mice, followed by intravitreal injections of anti-VEGF164 or vehicle, or no injection. In vivo OCT images were acquired using Micron III or InVivoVue systems at 7, 10, and/or 14 days post-laser and neovascular lesion volume was calculated as an ellipsoid. Subsequently, lesion volume was compared to that calculated from confocal Z-stack images of agglutinin-stained choroidal flatmounts. Results: Ellipsoid volume measurement of orthogonal 2-dimensional OCT images obtained from different imaging systems correlated with ex vivo lesion volumes for L-CNV (Spearman's ρ=0.82, 0.75, and 0.82 at days 7, 10, and 14, respectively). Ellipsoid volume calculation allowed temporal monitoring and evaluation of CNV lesions in response to antivascular endothelial growth factor treatment. Conclusions: Ellipsoid volume measurements allow rapid, quantitative use of OCT for the assessment of CNV lesions in vivo. This novel method can be used with different OCT imaging systems with sensitivity to distinguish between treatment conditions. It may serve as a useful adjunct to the standard ex vivo confocal quantification, to assess therapeutic efficacy in preclinical models of CNV, and in models of other ocular diseases. PMID:26060878

  9. Simple numerical method for predicting steady compressible flows

    NASA Technical Reports Server (NTRS)

    Von Lavante, E.; Melson, N. Duane

    1987-01-01

    The present numerical method for the solution of the isenthalpic form of the governing equations for compressible viscous and inviscid flows has its basis in the concept of flux vector splitting in its implicit form, and has been tested in the cases of several difficult viscous and inviscid configurations. An acceleration of time-marching to steady state is accomplished by implementing a multigrid procedure which effectively increases the convergence rate. The steady state results obtained are largely of good quality, and required only short computational times.

  10. Method for catalyzing oxidation/reduction reactions of simple molecules

    SciTech Connect

    Bicker, D.; Bonaventura, J.

    1988-06-14

    A method for oxidizing carbon monoxide to carbon dioxide is described comprising: (1) contacting, together, carbon monoxide, a nitrogen-containing chelating agent and water; wherein the chelating agent is at least one member selected from the group consisting of methmeoglobin bound to a support, ferric hemoglobin bound to a support, iron-containing porphyrins bound to a support, and sperm whale myoglobin bound to a support, wherein the support is glass, a natural fiber, a synthetic fiber, a gel, charcoal, carbon ceramic material, a metal oxide, a synthetic polymer, a zeolite, a silica compound of an alumina compound; and (2) obtaining carbon dioxide.

  11. Luminescent nanocrystals in the rare-earth niobate–zirconia system formed via hydrothermal method

    SciTech Connect

    Hirano, Masanori Dozono, Hayato

    2013-08-15

    Luminescent nanocrystals based on the rare-earth niobates (Ln{sub 3}NbO{sub 7}, Ln=Y, Eu) and zirconia (ZrO{sub 2}) that were composed of 50 mol% Ln{sub 3}NbO{sub 7} and 50 mol% ZrO{sub 2}, were hydrothermally formed as cubic phase under weakly basic conditions at 240 °C. The lattice parameter of the as-prepared nanoparticles corresponding to the composition of Y{sub 3−x}Eu{sub x}NbO{sub 7}–4ZrO{sub 2} that was estimated as a single phase of cubic gradually increased as the content of europium x increased. The existence of small absorbance peaks at 395 and 466 nm corresponding to the Eu{sup 3+7}F{sub 0}→{sup 5}L{sub 6}, and {sup 7}F{sub 0}→{sup 5}D{sub 2} excitation transition, respectively, was clearly observed in the diffuse reflectance spectra of the as-prepared samples containing europium. The optical band gap of the as-prepared samples was in the range from 3.5 to 3.7 eV. The photoluminescence spectra of the as-prepared nanocrystals containing europium showed orange and red luminescences with main peaks at 590 and 610 nm, corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 5}D{sub 0}→{sup 7}F{sub 2} transitions of Eu{sup 3+}, respectively, under excitation at 395 nm Xe lamp. The emission intensity corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 2} transition increased as heat-treatment temperature rose from 800 to 1200 °C. - Graphical abstract: This graphical abstract shows the excitation and emission spectra and a transmission electron microscopy image of nanocrystals (with composition based on the rare-earth niobates (Ln{sub 3}NbO{sub 7}, Ln=Y, Eu) and zirconia (ZrO{sub 2}) that were composed of 50 mol% Ln{sub 3}NbO{sub 7} and 50 mol% ZrO{sub 2}) formed via hydrothermal route. Display Omitted - Highlights: • Nanocrystals composed of 50 mol% Y{sub 3−x}Eu{sub x}NbO{sub 7} and 50 mol% ZrO{sub 2} was directly formed. • The nanocrystals were hydrothermally formed under weakly basic conditions at 240 °C. • The Y{sub 3}NbO{sub 7} showed

  12. Simple method for particle tracking with coherent synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Borland, M.

    2001-07-01

    Coherent synchrotron radiation (CSR) is of great interest to those designing accelerators as drivers for free-electron lasers (FELs). Although experimental evidence is incomplete, CSR is predicted to have potentially severe effects on the emittance of high-brightness electron beams. The performance of an FEL depends critically on the emittance, current, and energy spread of the beam. Attempts to increase the current through magnetic bunch compression can lead to increased emittance and energy spread due to CSR in the dipoles of such a compressor. The code elegant was used for design and simulation of the bunch compressor [M. Borland et al., in Proceedings of the 2000 Linear Accelerator Conference, Monterey, CA (SLAC, Menlo Park, CA, 2001), p. 863] for the low-energy undulator test line (LEUTL) FEL [S. V. Milton et al., Phys. Rev. Let. 85, 988 (1999)] at the Advanced Photon Source (APS). In order to facilitate this design, a fast algorithm was developed based on the 1D formalism of Saldin and co-workers [E. L. Saldin, E. A. Schneidmiller, and M. V. Yurkov, Nucl. Instrum. Methods Phys. Res., Sect. A 398, 373 (1997)]. In addition, a method of including CSR effects in drift spaces following the chicane magnets was developed and implemented. The algorithm is fast enough to permit running hundreds of tolerance simulations including CSR for 50 000 particles. This article describes the details of the implementation and shows results for the APS bunch compressor.

  13. Simple method for measuring reflectance of optical coatings

    SciTech Connect

    Wen Gui Wang; Yi Sheng Chen

    1995-12-31

    The quality of optical coatings has an important effect on the performance of optical instrument. The last few years, the requirements for super low loss dielectric mirror coatings used in low gain laser systems such as free electron laser and the ring laser etc., have given an impetus to the development of the technology of precise reflectance measurement of optical coatings. A reliable and workable technique is to measure the light intensity decay time of optical resonant cavity. This paper describes a measuring method which is dependent on direct measurement of the light intensity decay time of a resonant cavity comprised of low loss optical components. According to the evolution of a luminous flux stored inside the cavity, this method guarantees not only a quick and precise reflectance measurements of low loss highly reflecting mirror coatings but also transmittance measurements of low loss antireflection coatings and is especially effective with super los loss highly reflecting mirror. From the round-trip path length of the cavity and the speed of light, the light intensity exponential decay time of an optical cavity is easy to obtain and the cavity losses can be deduced. An optical reflectance of low loss highly mirror coatings and antireflection coatings is precisely measured as well. This is highly significant for the discrimination of the coating surface characteristics, the improvement of the performance of optical instrument and the development of high technology.

  14. A simple method for panretinal imaging with the slit lamp.

    PubMed

    Gellrich, Marcus-Matthias

    2016-12-01

    Slit lamp biomicroscopy of the retina with a convex lens is a key procedure in clinical practice. The methods presented enable ophthalmologists to adequately image large and peripheral parts of the fundus using a video-slit lamp and freely available stitching software. A routine examination of the fundus with a slit lamp and a +90 D lens is recorded on a video film. Later, sufficiently sharp still images are identified on the video sequence. These still images are imported into a freely available image-processing program (Hugin, for stitching mosaics together digitally) and corresponding points are marked on adjacent still images with some overlap. Using the digital stitching program Hugin panoramic overviews of the retina can be built which can extend to the equator. This allows to image diseases involving the whole retina or its periphery by performing a structured fundus examination with a video-slit lamp. Similar images with a video-slit lamp based on a fundus examination through a hand-held non-contact lens have not been demonstrated before. The methods presented enable those ophthalmologists without high-end imaging equipment to monitor pathological fundus findings. The suggested procedure might even be interesting for retinological departments if peripheral findings are to be documented which might be difficult with fundus cameras.

  15. Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity

    PubMed Central

    Phromviyo, Nutthakritta; Boueroy, Parichart; Chompoosor, Apiwat

    2016-01-01

    Background There is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity. Methods AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. Results The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 oC for 6 h and 200 oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in

  16. A SIMPLE METHOD FOR THE EXTRACTION AND QUANTIFICATION OF PHOTOPIGMENTS FROM SYMBIODINIUM SPP.

    EPA Science Inventory

    John E. Rogers and Dragoslav Marcovich. Submitted. Simple Method for the Extraction and Quantification of Photopigments from Symbiodinium spp.. Limnol. Oceanogr. Methods. 19 p. (ERL,GB 1192).

    We have developed a simple, mild extraction procedure using methanol which, when...

  17. A SIMPLE METHOD FOR THE EXTRACTION AND QUANTIFICATION OF PHOTOPIGMENTS FROM SYMBIODINIUM SPP.

    EPA Science Inventory

    John E. Rogers and Dragoslav Marcovich. Submitted. Simple Method for the Extraction and Quantification of Photopigments from Symbiodinium spp.. Limnol. Oceanogr. Methods. 19 p. (ERL,GB 1192).

    We have developed a simple, mild extraction procedure using methanol which, when...

  18. 17 CFR 162.7 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 2 2014-04-01 2014-04-01 false Reasonable and simple methods of opting out. 162.7 Section 162.7 Commodity and Securities Exchanges COMMODITY FUTURES TRADING... Affiliate Marketing Rules § 162.7 Reasonable and simple methods of opting out. (a) In general. A...

  19. 17 CFR 162.7 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Reasonable and simple methods of opting out. 162.7 Section 162.7 Commodity and Securities Exchanges COMMODITY FUTURES TRADING... Marketing Rules § 162.7 Reasonable and simple methods of opting out. (a) In general. A covered...

  20. A simple humane method to euthanize a sea turtle

    USGS Publications Warehouse

    Work, Thierry M.; Balazs, George H.

    2013-01-01

    Increased interconnectedness, communication, and demands of society require that wildlife professionals make every effort to consider animal welfare when handling animals. The challenge can be daunting, particularly when a wild animal needs to be euthanized. In some cases, biologists are in remote areas under conditions that may be less than ideal to properly and swiftly dispatch an animal, either because of a lack of proper supplies or veterinary training. Societal demands for consideration of animal welfare are not limited to wildlife professionals. Native cultures, fishermen and hunters have traditional methods of capturing or killing wildlife that are now under increasing public scrutiny. A current example is in Australia where aborigines were criticized for the practice of dispatching sea turtles by throwing a cement block at the animals’ heads resulting in negative public reaction (Queensland Times 2010).

  1. A simple humane method to euthanize a sea turtle

    USGS Publications Warehouse

    Work, Thierry M.; Balazs, George H.

    2013-01-01

    Increased interconnectedness, communication, and demands of society require that wildlife professionals make every effort to consider animal welfare when handling animals. The challenge can be daunting, particularly when a wild animal needs to be euthanized. In some cases, biologists are in remote areas under conditions that may be less than ideal to properly and swiftly dispatch an animal, either because of a lack of proper supplies or veterinary training. Societal demands for consideration of animal welfare are not limited to wildlife professionals. Native cultures, fishermen and hunters have traditional methods of capturing or killing wildlife that are now under increasing public scrutiny. A current example is in Australia where aborigines were criticized for the practice of dispatching sea turtles by throwing a cement block at the animals’ heads resulting in negative public reaction (Queensland Times 2010).

  2. siMS Score: Simple Method for Quantifying Metabolic Syndrome

    PubMed Central

    Soldatovic, Ivan; Vukovic, Rade; Culafic, Djordje; Gajic, Milan; Dimitrijevic-Sreckovic, Vesna

    2016-01-01

    Objective To evaluate siMS score and siMS risk score, novel continuous metabolic syndrome scores as methods for quantification of metabolic status and risk. Materials and Methods Developed siMS score was calculated using formula: siMS score = 2*Waist/Height + Gly/5.6 + Tg/1.7 + TAsystolic/130—HDL/1.02 or 1.28 (for male or female subjects, respectively). siMS risk score was calculated using formula: siMS risk score = siMS score * age/45 or 50 (for male or female subjects, respectively) * family history of cardio/cerebro-vascular events (event = 1.2, no event = 1). A sample of 528 obese and non-obese participants was used to validate siMS score and siMS risk score. Scores calculated as sum of z-scores (each component of metabolic syndrome regressed with age and gender) and sum of scores derived from principal component analysis (PCA) were used for evaluation of siMS score. Variants were made by replacing glucose with HOMA in calculations. Framingham score was used for evaluation of siMS risk score. Results Correlation between siMS score with sum of z-scores and weighted sum of factors of PCA was high (r = 0.866 and r = 0.822, respectively). Correlation between siMS risk score and log transformed Framingham score was medium to high for age groups 18+,30+ and 35+ (0.835, 0.707 and 0.667, respectively). Conclusions siMS score and siMS risk score showed high correlation with more complex scores. Demonstrated accuracy together with superior simplicity and the ability to evaluate and follow-up individual patients makes siMS and siMS risk scores very convenient for use in clinical practice and research as well. PMID:26745635

  3. One-Step Synthesis of Water-Soluble MoS2 Quantum Dots via a Hydrothermal Method as a Fluorescent Probe for Hyaluronidase Detection.

    PubMed

    Gu, Wei; Yan, Yinghan; Zhang, Cuiling; Ding, Caiping; Xian, Yuezhong

    2016-05-11

    In this work, a bottom-up strategy is developed to synthesize water-soluble molybdenum disulfide quantum dots (MoS2 QDs) through a simple, one-step hydrothermal method using ammonium tetrathiomolybdate [(NH4)2MoS4] as the precursor and hydrazine hydrate as the reducing agent. The as-synthesized MoS2 QDs are few-layered with a narrow size distribution, and the average diameter is about 2.8 nm. The resultant QDs show excitation-dependent blue fluorescence due to the polydispersity of the QDs. Moreover, the fluorescence can be quenched by hyaluronic acid (HA)-functionalized gold nanoparticles through a photoinduced electron-transfer mechanism. Hyaluronidase (HAase), an endoglucosidase, can cleave HA into proangiogenic fragments and lead to the aggregation of gold nanoparticles. As a result, the electron transfer is blocked and fluorescence is recovered. On the basis of this principle, a novel fluorescence sensor for HAase is developed with a linear range from 1 to 50 U/mL and a detection limit of 0.7 U/mL.

  4. Dry reforming of methane over Ni/MgO-Al2O3 catalysts prepared by two-step hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Zhang, Qian; Liu, Yi; Zhang, Yi

    2016-12-01

    Carbon dioxide reforming of methane has been investigated on a series of Ni/MgO-Al2O3 catalysts prepared by a simple two-step hydrothermal method. The sheet-like Ni/MgO-Al2O3 (15%) catalyst afforded as high as 52% CH4 conversion, which is almost six times higher than that of original Ni/MgO catalyst, with excellent stability during reaction, at relatively higher space velocity (6 × 105 cm3•g cat -1rad H-1) and lower reaction temperature (923 K). The effects of different ratio of Mg and Al have been investigated to understand the catalytic activity and coke formation for the obtained catalysts. The characterization results show that the addition Al2O3 to MgO would contribute to forming MgAl2O4 phase, which is stable and could effectively increase the CO2 adsorption due to the increased basic sites on the surface of catalyst, contributing to higher catalytic activity and better stability of this kind of catalyst during the dry reforming reaction. The catalysts were characterized by different techniques, such as BET, H2-TPR, XRD, SEM, CO2-TPD, TG-DTA and TEM analysis.

  5. One-pot synthesis and photoluminescence properties of core/porous-shell olive-like BaWO4 microstructure by a template-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhang, Suyue; Wang, Yunlong; Wang, Cuiping; Zhang, Hui; Shen, Yuhua; Xie, Anjian

    2016-02-01

    Core/porous-shell olive-like crystalline BaWO4 is synthesized by a combined simple hydrothermal method and soft template approach. The prepared product shows an olive-like shape with diameter of ˜2 μm, length of ˜4 μm, and the thickness of the shell of about 65 nm, which are orderly assembled by many nanoparticles. A possible formation mechanism of olive-like BaWO4 microstructure involving interfacial recognization of ions, nucleation, aggregation, in situ growth and Ostwald ripening process is proposed. Polyacrylic acid sodium (PAAS) as a template plays an important role in inducing the nucleation and growth of olive-like BaWO4 microcrystalline. Other shapes of BaWO4 microcrystalline are also fabricated by varying the concentration of PAAS and Ba2+. The olive-like product with a core-shell structure which exists a large number of pores on crystal surface shows excellent photoluminescence property, which have potentially applied prospects in fields such as light display systems etc.

  6. Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity.

    PubMed

    Tippayawat, Patcharaporn; Phromviyo, Nutthakritta; Boueroy, Parichart; Chompoosor, Apiwat

    2016-01-01

    There is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity. AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 (o)C for 6 h and 200 (o)C for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in pharmaceutical

  7. Characterization of visible-light-driven BiVO4 photocatalysts synthesized via a surfactant-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhang, Aiping; Zhang, Jinzhi

    2009-07-01

    Phase-pure BiVO4 photocatalysts were synthesized via a surfactant-assisted hydrothermal method and were characterized with XRD, DRS, Raman, FTIR and SEM. The results indicated that the HTAB-assisted BiVO4 had a narrow band gap than the other three products (no-surfactant-assisted, PVA-assisted and PVP-assisted BiVO4). The addition of surfactant would greatly affect the crystal structure of BiVO4, which can lead to different photocatalytic activities between them. Their photocatalytic activities were evaluated by the decolorization of methyl orange in aqueous solution under visible light irradiation; and the HTAB-assisted BiVO4 product, with well-assembled flower-like morphology, had a much higher photocatalytic activity (the photodegradation rate was about 85% in 90 min) than the other three products.

  8. Characterization of visible-light-driven BiVO4 photocatalysts synthesized via a surfactant-assisted hydrothermal method.

    PubMed

    Zhang, Aiping; Zhang, Jinzhi

    2009-07-15

    Phase-pure BiVO(4) photocatalysts were synthesized via a surfactant-assisted hydrothermal method and were characterized with XRD, DRS, Raman, FTIR and SEM. The results indicated that the HTAB-assisted BiVO(4) had a narrow band gap than the other three products (no-surfactant-assisted, PVA-assisted and PVP-assisted BiVO(4)). The addition of surfactant would greatly affect the crystal structure of BiVO(4), which can lead to different photocatalytic activities between them. Their photocatalytic activities were evaluated by the decolorization of methyl orange in aqueous solution under visible light irradiation; and the HTAB-assisted BiVO(4) product, with well-assembled flower-like morphology, had a much higher photocatalytic activity (the photodegradation rate was about 85% in 90 min) than the other three products.

  9. Synthesis and characterization of Co-doped zinc oxide nanorods prepared by ultrasonic spray pyrolysis and hydrothermal methods

    NASA Astrophysics Data System (ADS)

    Febrianti, Y.; Putri, N. A.; Sugihartono, I.; Fauzia, V.; Handoko, D.

    2017-07-01

    ZnO nanorods was synthesized by using ultrasonic spray pyrolysis deposition process and grown by hydrothermal method on a glass substrate. The influences of varying Co doping in structural, morphological and optical properties were investigated by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), and UV-Visible (UV-Vis) spectrometry, respectively. All the nanorods exhibit polycrystalline wurtzite structure with smaller crystalline size on the Co-doped nanorods. The nanorods also show no orientation alignment and random particle size. Interestingly, the nanorods with 3 wt.% Co doped shows high absorbance at UV and visible region indicating that optical properties of the ZnO nanorods have been modified by Co doping.

  10. Superparamagnetic and ferromagnetic behavior of ZnFe2O4 nanoparticles synthesized by microwave-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Phuruangrat, Anukorn; Maisang, Wachiraporn; Phonkhokkong, Thirawit; Thongtem, Somchai; Thongtem, Titipun

    2017-05-01

    Zinc ferrite (ZnFe2O4) nanoparticles were successfully synthesized from Zn(NO3)2 · 6H2O and Fe(NO3)3 · 9H2O by microwave hydrothermal method at 150°C for 1 h. Cubic ZnFe2O4 with particle size below 7 nm was formed in the solution at pH ≥ 6. The crystallinity and particle size of ZnFe2O4 nanoparticles were increased after calcination. The effects of pH of the precursor solution and calcination on the particle size and crystallinity of the particles were studied. At room temperature the products show superparamagnetic and ferromagnetic properties, determined by their size. The formation mechanism of ZnFe2O4 was also discussed according to the experimental results.

  11. Magnetic and Structural Properties of Cobalt- and Zinc-Substituted Nickel Ferrite Synthesized by Microwave-Assisted Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Sinfrônio, F. S. M.; Santana, P. Y. C.; Coelho, S. F. N.; Silva, F. C.; de Menezes, A. S.; Sharma, S. K.

    2017-02-01

    Ceramic spinel-based ferrites of cobalt, nickel and zinc were prepared by means of the microwave-assisted hydrothermal method. All samples were thoroughly characterized using different techniques for their structural, compositional, phonic and magnetic properties. The Rietveld analysis of x-ray powder diffraction data revealed the crystallinity as well single-phase partially inverse spinel structure. Wavelength dispersive x-ray fluorescence measurement indicates a good correlation between the empirical stoichiometry. The estimated average crystallite size varies between 9 nm and 13 nm (XRPD) and 6 and 14 nm for high-resolution transmission electron microscopy measurements. In addition, the observed micro-strain varies in the range of 0.01-0.6%. All samples show a quasi-spherical morphology and slight agglomeration. Infrared and Raman data spectra exhibit characteristic modes for spinel-based ferrites. Direct current magnetic measurements indicate behavior typical of magnetically soft materials system at 300 K.

  12. Polyphenolic contents and antioxidant activities of Lawsonia inermis leaf extracts obtained by microwave-assisted hydrothermal method.

    PubMed

    Zohourian, Tayyebeh Haleh; Quitain, Armando T; Sasaki, Mitsuru; Goto, Motonobu

    2011-01-01

    Extracts obtained by microwave-assisted hydrothermal extraction of Lawsonia inermis leaves were evaluated for the presence of polyphenolic compounds and antioxidant activities. Extraction experiments were performed in temperature-controlled mode at a range of 100 to 200 degrees C, and extraction time of 5 to 30 min, and microwave-controlled mode at a power from 300-700 W, in irradiation time of 30 to 120 s. Polyphenolic contents were measured using Folin-Ciocalteau method, while antioxidant properties were analyzed using DPPH radical scavenging activities (RSA) expressed in BHA equivalents. Results showed that best values of RSA were obtained at mild temperature range of 100-120 degrees C. Controlling microwave power at short irradiation time gave better results than temperature-controlled treatment as well. Furthermore, comparison with the result obtained at room temperature confirmed that the use of microwave was more effective for extracting polar components that normally possess higher antioxidant activities.

  13. Enhanced Visible-Light Photocatalytic Activity of C/Ce-Codoped ZnO Nanoellipsoids Synthesized by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Ha, Luu Thi Viet; Dai, Luu Minh; Nhiem, Dao Ngoc; Van Cuong, Nguyen

    2016-08-01

    C/Ce-codoped ZnO nanomaterial has been synthesized by a hydrothermal method and its physical properties and characterization investigated using thermogravimetric and differential thermal analysis (TG-DTA), x-ray diffraction (XRD) analysis, Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive x-ray (EDX) spectroscopy, UV-Vis diffuse reflectance spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of the nanomaterial was examined using methylene blue as organic dye under visible-light source. The results show that the C/Ce-codoped ZnO nanomaterial exhibited higher photocatalytic activity under visible-light irradiation compared with undoped ZnO, Ce-doped ZnO or C-doped ZnO nanomaterials. Such enhancement of the photocatalytic activity of C/Ce-codoped ZnO under visible-light irradiation suggests that these nanoparticles might have good applications in optoelectronics and wastewater treatment.

  14. Synthesis and enhanced photocatalytic property of feather-like Cd-doped CuO nanostructures by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Wang, Yongqian; Jiang, Tingting; Meng, Dawei; Wang, Dagui; Yu, Meihua

    2015-11-01

    Feather-like Cd-doped CuO nanostructures were fabricated by a one-step hydrothermal method. X-ray diffraction pattern (XRD) and field emission scanning electron microscopy (FESEM) demonstrated that Cd2+ entered the crystal lattice of CuO and substituted Cu2+ without destroying crystal structures to form feather-like CuO nanostructures. The optical property of Cd-doped CuO was investigated by using UV-vis spectrophotometer. A slight blue-shift of optical band gap was observed because of quantum confinement effect. The doped samples exhibited obviously higher absorbance in UV light region and better photocatalytic activity for the photodegradation of methyl blue than the pure CuO nanosheets.

  15. Auscultatory percussion: a simple method to detect pleural effusion.

    PubMed

    Guarino, J R; Guarino, J C

    1994-02-01

    To assess a new technique for the detection of free pleural fluid. 118 consecutive inpatients with radiologic evidence of free pleural fluid and a control group of 175 randomly selected inpatients were examined over a three-year period in a prospective blind study by auscultatory percussion (AP) for evidence of pleural effusion. The cutoff in the percussion note by AP is strikingly loud and sharp at the fluid level and allows precise delineation of even minimal amounts of pleural fluid. The fluid level was measured in reference to the last rib. The criterion for detection of pleural effusion by AP was a demonstrable horizontal fluid level at the sound cutoff across the posterior hemithorax above the last rib that shifted with lateral tilt. A general medical and surgical university-affiliated teaching Veterans Affairs hospital. All inpatients were eligible. Ready availability of examiners was essential. Rotating third- and fourth-year medical students, residents, and senior staff members participated. None. 113 of the 118 patients with radiologic evidence of pleural effusion had a distinct horizontal fluid level above the last rib that shifted with lateral tilt (sensitivity = 95.8%). None of the 175 control patients examined at random showed evidence of pleural effusion by AP examination, which was confirmed by chest radiography (specificity = 100%). Nine of the 175 patients without radiologic evidence of pleural effusion had elevated diaphragms that simulated a fluid level in the examination by AP. Each of the nine patients, however, had no shift in the level with lateral tilt. Subpulmonic effusions were readily displaced and identified by this method of AP. Examination by AP is highly sensitive and specific for the detection of free pleural fluid, even in the presence of obesity, thickened pleura, lung masses, pneumonia, and associated lung disease. The examination correlates closely with standard and lateral decubitus chest radiography. Pleural effusion

  16. Fingerprints: A simple method for Screening Hemophilic Patients.

    PubMed

    Jamalian, M; Mesri, M; Vishteh, H R K; Solhi, H; Salehpour, R

    2014-08-01

    The present study aims to compare hemophilic patients' fingerprint types with the normal people to help diagnose the disease, particularly new occurrences of the disease. This case-control study was conducted in 2012. Sixty two patients with hemophilia type A and 62 normal healthy people were selected. The type of fingerprint was determined by a forensic specialist who was kept unaware of the participants' group. Using advanced Henry method, the main types of fingerprints were classified as arch, loop, whorl, as well as other types. In the control group, loop type (65%) and in the case group the whorl type (34%) were the most frequent fingerprint type (p < 0.001) and there was a significant difference of fingerprint in each finger between two groups. In addition, the average number of whorl type in the patients with mild disease was significantly higher and the average number of arch and other types of fingerprints was significantly lower than patients with moderate or severe disease. The findings of the present study indicated that not only are the fingerprints of normal and hemophilic people different, but also a difference was observed between hemophilic patients with the mild factor level and patients with moderate or severe one.

  17. Rapid and simple method of qPCR primer design.

    PubMed

    Thornton, Brenda; Basu, Chhandak

    2015-01-01

    Quantitative real-time polymerase chain reaction (qPCR) is a powerful tool for analysis and quantification of gene expression. It is advantageous compared to traditional gel-based method of PCR, as gene expression can be visualized "real-time" using a computer. In qPCR, a reporter dye system is used which intercalates with DNA's region of interest and detects DNA amplification. Some of the popular reporter systems used in qPCR are the following: Molecular Beacon(®), SYBR Green(®), and Taqman(®). However, success of qPCR depends on the optimal primers used. Some of the considerations for primer design are the following: GC content, primer self-dimer, or secondary structure formation. Freely available software could be used for ideal qPCR primer design. Here we have shown how to use some freely available web-based software programs (such as Primerquest(®), Unafold(®), and Beacon designer(®)) to design qPCR primers.

  18. Simple method for screening of alpha-thalassaemia 1 carriers.

    PubMed

    Tayapiwatana, Chatchai; Kuntaruk, Surakit; Tatu, Thanusak; Chiampanichayakul, Sawitree; Munkongdee, Thongperm; Winichagoon, Pranee; Fuchareon, Suthat; Kasinrerk, Watchara

    2009-06-01

    Alpha-thalassaemia 1 genetic disorder occurs when there is a deletion of two linked alpha-globin genes. The interaction between these abnormal genes leads to the most severe type of thalassaemia disease, haemoglobin (Hb) Bart's hydrops fetalis. The identification of alpha-thalassaemia 1 carriers and genetic counselling are essential for the prevention and control of severe thalassaemia diseases. In this study, we have developed a rapid screening method for identifying alpha-thalassaemia 1. A sandwich-type immunochromatographic (IC) strip test was developed, using the generated monoclonal anti-Hb Bart's antibody, to trace the Hb Bart's in haemolysates. When assayed by our IC strip test, all alpha-thalassaemia 1, HbH disease, HbH-Constant Spring (H-CS) disease, HbH-CS and heterozygous HbE (CSEA) Bart's disease, and homozygous alpha-thalassaemia 2 showed positive results. No false negative results were observed in these blood samples. In alpha-thalassaemia 2 heterozygotes, 83% of them showed positive reactivity. Among HbE (both homozygotes and heterozygotes), beta-thalassaemia (heterozygotes, homozygotes and beta-thalassaemia/HbE) and normal subjects, the IC strip test revealed negative reactivity of 100, 85 and 97%, respectively. These results indicate that this novel immunodiagnostic kit, in combination with red blood cell indices, is suitable for screening and ruling out mass populations for the presence of alpha-thalassaemia 1.

  19. A Simple and Efficient Protein Structure Refinement Method.

    PubMed

    Cheng, Qianyi; Joung, InSuk; Lee, Jooyoung

    2017-09-14

    Improving the quality of a given protein structure can serve as the ultimate solution for accurate protein structure prediction, and seeking such a method is currently a challenge in computational structural biology. In order to promote and encourage much needed such efforts, CASP (Critical Assessment of Structure Prediction) has been providing an ideal computational experimental platform, where it was reported only recently (since CASP10) that systematic protein structure refinement is possible by carrying out extensive (approximately millisecond) MD simulations with proper restraints generated from the given structure. Using an explicit solvent model and much reduced positional and distance restraints than previously exercised, we propose a refinement protocol that combines a series of short (5 ns) MD simulations with energy minimization procedures. Testing and benchmarking on 54 CASP8-10 refinement targets and 34 CASP11 refinement targets shows quite promising results. Using only a small fraction of MD simulation steps (nanosecond versus millisecond), systematic protein structure refinement was demonstrated in this work, indicating that refinement of a given model can be achieved using a few hours of desktop computing.

  20. A simple method to improve the stability of docetaxel micelles

    PubMed Central

    Zhang, Lan; Tan, LiWei; Chen, LiJuan; Chen, XiaoXin; Long, ChaoFeng; Peng, JinRong; Qian, ZhiYong

    2016-01-01

    Self-assembled polymeric micelles have been widely applied in drug delivery systems. In this study, we found that pH value of micellar system solution was the decisive factor of physical stability. Furthermore, the weak basic solution could maintain the solution clarification for a relative long time. To investigate the stability of polymeric micelles in different pH solutions, the micellar particle size and the docetaxel content remaining in solution were detected at predetermined time points. The crystallographic assay of freeze-drying powder was characterized by an X-ray diffractometer. In vitro release results indicated that the PBS had little influence on the sustained-release effect of docetaxel-loaded polymeric micelles (DPM). Besides, the safety of micellar formulation was determined by an MTT assay on HEK293 cells, and the anti-tumor activity was tested on MCF-7 cells. The results demonstrated that DPM adjusted with PBS (DPM (PBS)) was of low toxicity and maintained the effectiveness of docetaxel. In vivo antitumor results indicated that DPM (PBS) had better antitumor efficacy than common docetaxel injection (DTX). Thus it was concluded that regulation of micellar solution PH by PBS is a safe and effective method to improve the physical stability of DPM. It might promote the application of micellar formulation in clinical applications. PMID:27833135

  1. Synthesis and optical characteristics of yttrium-doped zinc oxide nanorod arrays grown by hydrothermal method.

    PubMed

    Park, Hyunggil; Kim, Younggyu; Ji, Iksoo; Lee, Sang-Heon; Kim, Jin Soo; Kim, Jin Soo; Leem, Jae-Young

    2014-11-01

    Yttrium-doped ZnO (YZO) nanorods were synthesized by hydrothermal growth on a quartz substrate with various post-annealing temperatures. To investigate the effects of post-annealing on the optical properties and parameters of the nanorods, X-ray diffractometry (XRD), photoluminescence (PL) measurement, and ultraviolet (UV)-visible spectroscopy were used. From the XRD investigation, the full width at half maximum (FWHM) and the dislocation density of the nanorods was found to increase with an increase in the post-annealing temperature. In the PL spectra, the intensity of the near band edge (NBE) emission peak in the UV region also increases with an increase in the temperature of post-annealing. The deep level emission (DLE) peak in the visible region changes with various post-annealing temperatures, and its intensity increases remarkably with post-annealing at 800 degrees C. In this paper, changes in the optical parameters of the nanorods caused by variation in the behavior of Y during post-annealing was investigated, with properties such as absorption coefficients, refractive indices, and dispersion parameters being obtained from transmittance and reflectance analysis.

  2. Hydrothermal growth and morphology evolution of CePO{sub 4} aggregates by a complexing method

    SciTech Connect

    Ma Lin; Chen Weixiang Zheng Yifan; Xu Zhude

    2008-11-03

    A facile hydrothermal route assisted by Na{sub 2}H{sub 2}EDTA (ethylenediaminetetraacetic acid disodium) has been successfully developed to prepare uniform cerium phosphate (CePO{sub 4}) aggregates with different morphologies, such as peanut-like and spindle-like. It was found that the as-prepared uniform CePO{sub 4} aggregates were constructed with many nearly parallel aligned nanorods. The molar ratio of EDTA/Ce{sup 3+}, solution pH and reaction time had great influences on the morphologies and sizes of the CePO{sub 4} samples. In our process of synthesis, Na{sub 2}H{sub 2}EDTA played important roles as complexing reagent and inducing agent on the formation of CePO{sub 4} aggregates. The possible growth mechanism for CePO{sub 4} aggregates was presented. Ce{sub 0.9}Tb{sub 0.1}PO{sub 4} aggregates with different morphologies were also prepared and their photoluminescence properties were characterized.

  3. Fabrication and Magnetic Properties of Sn-Doped ZnO Microstructures via Hydrothermal Method.

    PubMed

    Farooq, M Hassan; Hussain, Riaz; Iqbal, M Zubair; Shah, M W; Rana, Usman Ali; Khan, Salah Ud-Din

    2016-01-01

    Pure zinc oxide (ZnO) and Sn-doped ZnO hexagonal sheets were synthesized by template free hydrothermal growth mechanism with controlled morphology by using zinc acetate dihydrate (Zn(CH₃COO)₂· 2H₂O), tin chloride pentahydrate (SnCl₄ · 5H₂O), Polyvinylpyrrolidone (PVP) and H₂O as precursors. The structural, physical, chemical, and magnetic characteristics were investigated by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy and alternating gradient magnetometer (AGM), respectively. The average crystalline size of hexagonal phase of ZnO sheets was calculated to be about 34 nm from XRD patterns. Energy dispersive spectroscopy provided the compositional analysis of pure and Sn-doped ZnO. Room temperature ferromagnetism (RTFM) was observed by AGM for pure and Sn-doped ZnO hexagonal plates. RTFM increases monotonically for Sn doping and reaches maximum saturation magnetization 0.045 emu/g for 3% Sn-doped ZnO.

  4. A simple method for assessing intestinal inflammation in Crohn's disease

    PubMed Central

    Tibble, J; Teahon, K; Thjodleifsson, B; Roseth, A; Sigthorsson, G; Bridger, S; Foster, R; Sherwood, R; Fagerhol, M; Bjarnason, I

    2000-01-01

    BACKGROUND AND AIMS—Assessing the presence and degree of intestinal inflammation objectively, simply, and reliably is a significant problem in gastroenterology. We assessed faecal excretion of calprotectin, a stable neutrophil specific marker, as an index of intestinal inflammation and its potential use as a screening test to discriminate between patients with Crohn's disease and those with irritable bowel syndrome.
METHODS—The validity of faecal calprotectin as a marker of intestinal inflammation was assessed in 22 patients with Crohn's disease (35 studies) by comparing faecal excretions and concentrations using four day faecal excretion of 111indium white cells. A cross sectional study assessed the sensitivity of faecal calprotectin concentration for the detection of established Crohn's disease (n=116). A prospective study assessed the value of faecal calprotectin in discriminating between patients with Crohn's disease and irritable bowel syndrome in 220 patients referred to a gastroenterology clinic.
RESULTS—Four day faecal excretion of 111indium (median 8.7%; 95% confidence interval (CI) 7-17%; normal <1.0%) correlated significantly (p<0.0001) with daily (median ranged from 39 to 47 mg; normal <3 mg; r=0.76-0.82) and four day faecal calprotectin excretion (median 101 mg; 95% CI 45-168 mg; normal <11 mg; r=0.80) and single stool calprotectin concentrations (median 118 mg/l; 95% CI 36-175 mg/l; normal <10 mg/l; r=0.70) in patients with Crohn's disease. The cross sectional study showed a sensitivity of 96% for calprotectin in discriminating between normal subjects (2 mg/l; 95% CI 2-3 mg/l) and those with Crohn's disease (91 mg/l; 95% CI 59-105 mg/l). With a cut off point of 30 mg/l faecal calprotectin has 100% sensitivity and 97% specificity in discriminating between active Crohn's disease and irritable bowel syndrome.
CONCLUSION—The calprotectin method may be a useful adjuvant for discriminating between patients with Crohn's disease and

  5. A Simple and Practical Method for Setting Up a Criterion of Projection of Silicone Breast Implant After Simple Mastectomy

    PubMed Central

    Ando, Jiro; Harao, Michiko; Takemae, Masaru; Kishi, Kazuo

    2017-01-01

    Objective: In breast reconstruction, decision of projection of silicone breast implant in tissue expander replacement is difficult because of the need to consider several parameters that cannot be expressed in accurate numerical form. The present study aimed at a quantitative analysis based on decreased projection of the reconstructed side compared with silicone breast implant projection and to develop a new method for simple and practical decision of silicone breast implant projection. Methods: Thirty-five patients who had mammary carcinoma and were treated with simple mastectomy, tissue expander insertion, and replacement with anatomical silicone breast implant from April 2013 to March 2016 were retrospectively identified. We recorded the projection of used silicone breast implant (Pi). The projections of reconstructed breast 6 months after silicone breast implant insertion (Pr) and that of the unaffected breast during silicone breast implant selection (Pu) were measured. The difference between Pi and Pr was defined as the revised numerical value (Rev). We investigated whether Rev significantly differed according to age, body mass index, or Pu and analyzed correlations between Rev and age, Pu, and body mass index. Results: Mean Rev in all patients was 1.2 ± 0.3 cm. Rev was significantly higher in patients with higher body mass index than in those with lower body mass index (P < .01) and in patients with higher Pu than in those with lower Pu (P < .01). Significant positive correlations of Rev with body mass index and Pu were found (β = .63, P < .01 and β = .67, P < .01, respectively). Conclusions: Rev was a simple, practical, and cost-effective concept. We believe that it is a useful indicator for deciding silicone breast implant projection. PMID:28890745

  6. A Simple and Practical Method for Setting Up a Criterion of Projection of Silicone Breast Implant After Simple Mastectomy.

    PubMed

    Ishii, Naohiro; Ando, Jiro; Harao, Michiko; Takemae, Masaru; Kishi, Kazuo

    2017-01-01

    Objective: In breast reconstruction, decision of projection of silicone breast implant in tissue expander replacement is difficult because of the need to consider several parameters that cannot be expressed in accurate numerical form. The present study aimed at a quantitative analysis based on decreased projection of the reconstructed side compared with silicone breast implant projection and to develop a new method for simple and practical decision of silicone breast implant projection. Methods: Thirty-five patients who had mammary carcinoma and were treated with simple mastectomy, tissue expander insertion, and replacement with anatomical silicone breast implant from April 2013 to March 2016 were retrospectively identified. We recorded the projection of used silicone breast implant (Pi). The projections of reconstructed breast 6 months after silicone breast implant insertion (Pr) and that of the unaffected breast during silicone breast implant selection (Pu) were measured. The difference between Pi and Pr was defined as the revised numerical value (Rev). We investigated whether Rev significantly differed according to age, body mass index, or Pu and analyzed correlations between Rev and age, Pu, and body mass index. Results: Mean Rev in all patients was 1.2 ± 0.3 cm. Rev was significantly higher in patients with higher body mass index than in those with lower body mass index (P < .01) and in patients with higher Pu than in those with lower Pu (P < .01). Significant positive correlations of Rev with body mass index and Pu were found (β = .63, P < .01 and β = .67, P < .01, respectively). Conclusions: Rev was a simple, practical, and cost-effective concept. We believe that it is a useful indicator for deciding silicone breast implant projection.

  7. [Principle of LAMP method--a simple and rapid gene amplification method].

    PubMed

    Ushikubo, Hiroshi

    2004-06-01

    So far nucleic acid test (NAT) has been employed in various fields, including infectious disease diagnoses. However, due to its complicated procedures and relatively high cost, it has not been widely utilized in many actual diagnostic applications. We have therefore developed a simple and rapid gene amplification technology, Loop-mediated Isothermal Amplification (LAMP) method, which has shown prominent results of surpassing the performance of the conventional gene amplification methods. LAMP method acquires three main features: (1) all reaction can be carried out under isothermal conditions; (2) the amplification efficiency is extremely high and tremendous amount of amplification products can be obtained; and (3) the reaction is highly specific. Furthermore, developed from the standard LAMP method, a rapid LAMP method, by adding in the loop primers, can reduce the amplification time from the previous 1 hour to less than 30 minutes. Enormous amount of white precipitate of magnesium pyrophosphate is produced as a by-product of the amplification, therefore, direct visual detection is possible without using any reaction indicators and detection equipments. We believe LAMP technology, with the integration of these features, can rightly apply to clinical genetic testing, food and environmental analysis, as well as NAT in different fields.

  8. Structural and morphology of ZnO nanorods synthesized using ZnO seeded growth hydrothermal method and its properties as UV sensing.

    PubMed

    Ridhuan, Nur Syafinaz; Razak, Khairunisak Abdul; Lockman, Zainovia; Abdul Aziz, Azlan

    2012-01-01

    In this study, zinc oxide (ZnO) nanorod arrays were synthesized using a simple hydrothermal reaction on ZnO seeds/n-silicon substrate. Several parameters were studied, including the heat-treatment temperature to produce ZnO seeds, zinc nitrate concentration, pH of hydrothermal reaction solution, and hydrothermal reaction time. The optimum heat-treatment temperature to produce uniform nanosized ZnO seeds was 400°C. The nanorod dimensions depended on the hydrothermal reaction parameters. The optimum hydrothermal reaction parameters to produce blunt tip-like nanorods (770 nm long and 80 nm in top diameter) were 0.1 M zinc nitrate, pH 7, and 4 h of growth duration. Phase analysis studies showed that all ZnO nanorods exhibited a strong (002) peak. Thus, the ZnO nanorods grew in a c-axis preferred orientation. A strong ultraviolet (UV) emission peak was observed for ZnO nanorods grown under optimized parameters with a low, deep-level emission peak, which indicated high optical property and crystallinity of the nanorods. The produced ZnO nanorods were also tested for their UV-sensing properties. All samples responded to UV light but with different sensing characteristics. Such different responses could be attributed to the high surface-to-volume ratio of the nanorods that correlated with the final ZnO nanorods morphology formed at different synthesis parameters. The sample grown using optimum synthesis parameters showed the highest responsivity of 0.024 A/W for UV light at 375 nm under a 3 V bias.

  9. Hierarchical MnO2 nanosheets synthesized via electrodeposition-hydrothermal method for supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Zheng, Dongdong; Qiang, Yujie; Xu, Shenying; Li, Wenpo; Yu, Shanshan; Zhang, Shengtao

    2017-02-01

    Metal oxides have emerged as one kind of important supercapacitor electrode materials. Herein, we report hierarchical MnO2 nanosheets prepared of indium tin oxide (ITO) coated glass substrates via a hybrid two-step protocol, including a cathodic electrodeposition technique and a hydrothermal process. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX), and transmission electron microscope (TEM). SEM and TEM images show that the as-synthesized MnO2 nanosheets are hierarchical and porous, which could increase the active surface and short paths for fast ion diffusion. The results of nitrogen adsorption-desorption analysis indicate that the BET surface area of the MnO2 nanosheets is 53.031 m2 g-1. Furthermore, the electrochemical properties of the MnO2 are elucidated by cyclic voltammograms (CV), galvanostatic charge-discharge (GCD) tests, and electrochemical impedance spectroscopy (EIS) in 0.1 M Na2SO4 electrolyte. The electrochemical results demonstrate that the as-grown MnO2 nanosheet exhibits an excellent specific capacitance of 335 F g-1 at 0.5 A g-1 when it is applied as a potential electrode material for an electrochemical supercapacitor. Additionally, the MnO2 nanosheet electrode also presents high rate capability and good cycling stability with 91.8% retention after 1000 cycles. These excellent properties indicate that the hierarchical MnO2 nanosheets are a potential electrode material for electrochemical supercapacitors.

  10. Growth of single crystals under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Popolitov, Vladislav Ivanovich; Litvin, Boris Nikolaevich

    The book summarizes the available theoretical, methodological, and experimental data on the hydrothermal growth of inorganic compounds, such as simple and complex oxides, sulfides, silicates, germanates, phosphates, niobates, and tantalates. Attention is given to the physicochemical, hydrodynamic, and kinetic characteristics of the growth of these compounds, as well as hydrothermal growth techniques and equipment. The discussion also covers the morphogenetic characteristics of hydrothermally grown single crystals, their principal physical properties, and X-ray diffraction and structural data.

  11. On a New Simple Method for Evaluation of Certain Multiple Definite Integrals

    ERIC Educational Resources Information Center

    Sen Gupta, I.; Debnath, L.

    2006-01-01

    This paper deals with a simple method of evaluation of certain multiple definite integrals. This is followed by two main theorems concerning multiple definite integrals. Some examples of applications are given.

  12. A Simple Method to Measure the Angular Speed of a Spinning Object

    ERIC Educational Resources Information Center

    Misra, Raj M.

    2008-01-01

    The angular speed of a spinning object is commonly measured using a stroboscope or a mechanically or optically coupled tachometer. We present here an alternate, simple, and instructive method to measure it using a microphone and a computer.

  13. A Simple Method to Measure the Angular Speed of a Spinning Object

    ERIC Educational Resources Information Center

    Misra, Raj M.

    2008-01-01

    The angular speed of a spinning object is commonly measured using a stroboscope or a mechanically or optically coupled tachometer. We present here an alternate, simple, and instructive method to measure it using a microphone and a computer.

  14. Solving the Phase Problem in Crystal Structure Determination: A Simple Introduction to Direct Methods.

    ERIC Educational Resources Information Center

    Schenk, H.

    1979-01-01

    Presents a simple way to introduce Direct Methods program systems to solve phase problems in x-ray crystal structure determination. It is intended for the undergraduate chemistry student laboratory. (Author/SA)

  15. A simple method for calculating the characteristics of the Dutch roll motion of an airplane

    NASA Technical Reports Server (NTRS)

    Klawans, Bernard B

    1956-01-01

    A simple method for calculating the characteristics of the Dutch roll motion of an airplane is obtained by arranging the lateral equations of motion in such form and order that an iterative process is quickly convergent.

  16. [Analysis on the accuracy of simple selection method of Fengshi (GB 31)].

    PubMed

    Li, Zhixing; Zhang, Haihua; Li, Suhe

    2015-12-01

    To explore the accuracy of simple selection method of Fengshi (GB 31). Through the study of the ancient and modern data,the analysis and integration of the acupuncture books,the comparison of the locations of Fengshi (GB 31) by doctors from all dynasties and the integration of modern anatomia, the modern simple selection method of Fengshi (GB 31) is definite, which is the same as the traditional way. It is believed that the simple selec tion method is in accord with the human-oriented thought of TCM. Treatment by acupoints should be based on the emerging nature and the individual difference of patients. Also, it is proposed that Fengshi (GB 31) should be located through the integration between the simple method and body surface anatomical mark.

  17. On a New Simple Method for Evaluation of Certain Multiple Definite Integrals

    ERIC Educational Resources Information Center

    Sen Gupta, I.; Debnath, L.

    2006-01-01

    This paper deals with a simple method of evaluation of certain multiple definite integrals. This is followed by two main theorems concerning multiple definite integrals. Some examples of applications are given.

  18. A Simple Design Method Based on Vector Control of AC Machines with LC Filter

    NASA Astrophysics Data System (ADS)

    Saito, Ryosuke; Kubota, Hisao

    This paper presents a simple voltage control system of AC machines using PWM voltage source inverter with output LC filters. By assuming a motor as a current source, the voltage is controlled by a simple proportional differential (PD) control. The vector control and PD control can be separately controlled in this system. A method for disturbance rejection is also described. The effectiveness of the proposed method is verified by simulations and experiments.

  19. Sensitive and selective detection of Hg2+ and Cu2+ ions by fluorescent Ag nanoclusters synthesized via a hydrothermal method

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Ren, Xiangling; Meng, Xianwei; Fang, Zheng; Tang, Fangqiong

    2013-09-01

    An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a reusable detection method for Cu2+. Furthermore, the different quenching phenomena caused by the two metals ions such as changes in visible colour, shifts of UV absorbance peaks and changes in size of Ag NCs make it easy to distinguish between them. Therefore the easily synthesized fluorescent Ag NCs may have great potential as Hg2+ and Cu2+ ions sensors.An easily prepared fluorescent Ag nanoclusters (Ag NCs) probe for the sensitive and selective detection of Hg2+ and Cu2+ ions was developed here. The Ag NCs were synthesized by using polymethacrylic acid sodium salt as a template via a convenient hydrothermal process. The as-prepared fluorescent Ag NCs were monodispersed, uniform and less than 2 nm in diameter, and can be quenched in the presence of mercury (Hg2+) or copper (Cu2+) ions. Excellent linear relationships existed between the quenching degree of the Ag NCs and the concentrations of Hg2+ or Cu2+ ions in the range of 10 nM to 20 μM or 10 nM to 30 μM, respectively. By using ethylenediaminetetraacetate (EDTA) as the masking agent of Cu2+, Hg2+ was exclusively detected in coexistence with Cu2+ with high sensitivity (LOD = 10 nM), which also provided a

  20. Structure and phase transition of BiFeO{sub 3} cubic micro-particles prepared by hydrothermal method

    SciTech Connect

    Zhou, Jian-Ping; Yang, Ruo-Lin; Xiao, Rui-Juan; Chen, Xiao-Ming; Deng, Chao-Yong

    2012-11-15

    Graphical abstract: Bismuth ferrite (BiFeO{sub 3}) cubic micro-particles with smooth surfaces were synthesized. BiFeO{sub 3} has a hexagonal perovskite structure with a space group R3c below 370 °C and rhombohedral perovskite structure with a space group R3m below 755 °C, undergoes a phase transition in the temperature range of 755–817 °C to a cubic structure, then decompose to liquid and Fe{sub 2}O{sub 3} above 939 °C. Highlights: ► BiFeO{sub 3} micro-particles with smooth surface were synthesized by hydrothermal method. ► BiFeO{sub 3} enjoys hexagonal structure with well element ratio and chemical valence. ► BiFeO{sub 3} transition from rhombohedral phase to cubic phase lasts 60 °C. -- Abstract: Single-phase bismuth ferrite (BiFeO{sub 3}) powders were synthesized with a hydrothermal method by controlling the experimental conditions carefully. The powder structure, morphology and composition were characterized by using X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Raman measurement and X-ray photoelectron spectroscopy. The particles change from irregular agglomerations to regular cubes with increasing KOH concentration. The large BiFeO{sub 3} cubic particles enjoy much smooth surfaces with well-matched element ratio (Bi:Fe:O = 1:1:3) and chemical valence (Bi{sup 3+}, Fe{sup 3+} and O{sup 2−}). The high temperature XRD and differential scanning calorimetry show that BiFeO{sub 3} powders have a hexagonal perovskite structure with a space group R3c below 370 °C and a rhombohedral structure with a space group R3m below 755 °C. BiFeO{sub 3} undergoes a phase transition in the temperature range of 755–817 °C from rhombohedral structure to a cubic phase, then decomposes to liquid and Fe{sub 2}O{sub 3} above 939 °C.

  1. Hydrothermal Processes

    NASA Astrophysics Data System (ADS)

    German, C. R.; von Damm, K. L.

    2003-12-01

    What is Hydrothermal Circulation?Hydrothermal circulation occurs when seawater percolates downward through fractured ocean crust along the volcanic mid-ocean ridge (MOR) system. The seawater is first heated and then undergoes chemical modification through reaction with the host rock as it continues downward, reaching maximum temperatures that can exceed 400 °C. At these temperatures the fluids become extremely buoyant and rise rapidly back to the seafloor where they are expelled into the overlying water column. Seafloor hydrothermal circulation plays a significant role in the cycling of energy and mass between the solid earth and the oceans; the first identification of submarine hydrothermal venting and their accompanying chemosynthetically based communities in the late 1970s remains one of the most exciting discoveries in modern science. The existence of some form of hydrothermal circulation had been predicted almost as soon as the significance of ridges themselves was first recognized, with the emergence of plate tectonic theory. Magma wells up from the Earth's interior along "spreading centers" or "MORs" to produce fresh ocean crust at a rate of ˜20 km3 yr-1, forming new seafloor at a rate of ˜3.3 km2 yr-1 (Parsons, 1981; White et al., 1992). The young oceanic lithosphere formed in this way cools as it moves away from the ridge crest. Although much of this cooling occurs by upward conduction of heat through the lithosphere, early heat-flow studies quickly established that a significant proportion of the total heat flux must also occur via some additional convective process (Figure 1), i.e., through circulation of cold seawater within the upper ocean crust (Anderson and Silbeck, 1981). (2K)Figure 1. Oceanic heat flow versus age of ocean crust. Data from the Pacific, Atlantic, and Indian oceans, averaged over 2 Ma intervals (circles) depart from the theoretical cooling curve (solid line) indicating convective cooling of young ocean crust by circulating seawater

  2. Structural, spectroscopic, and magnetic properties of Eu3+-doped GdVO4 nanocrystals synthesized by a hydrothermal method.

    PubMed

    Szczeszak, Agata; Grzyb, Tomasz; Śniadecki, Zbigniew; Andrzejewska, Nina; Lis, Stefan; Matczak, Michał; Nowaczyk, Grzegorz; Jurga, Stefan; Idzikowski, Bogdan

    2014-12-01

    New interesting aspects of the spectroscopic properties, magnetism, and method of synthesis of gadolinium orthovanadates doped with Eu(3+) ions are discussed. Gd(1-x)Eu(x)VO4 (x = 0, 0.05, 0.2) bifunctional luminescent materials with complex magnetic properties were synthesized by a microwave-assisted hydrothermal method. Products were formed in situ without previous precipitation. The crystal structures and morphologies of the obtained nanomaterials were analyzed by X-ray diffraction and transmission and scanning electron microscopy. Crystallographic data were analyzed using Rietveld refinement. The products obtained were nanocrystalline with average grain sizes of 70-80 nm. The qualitative and quantitative elemental composition as well as mapping of the nanocrystals was proved using energy-dispersive X-ray spectroscopy. The spectroscopic properties of red-emitting nanophosphors were characterized by their excitation and emission spectra and luminescence decays. Magnetic measurements were performed by means of vibrating sample magnetometry. GdVO4 and Gd0.8Eu0.2VO4 exhibited paramagnetic behavior with a weak influence of antiferromagnetic couplings between rare-earth ions. In the substituted sample, an additional magnetic contribution connected with the population of low-lying excited states of europium was observed.

  3. Nitrogen isotopes determination in natural gas: analytical method and first results on magmatic, hydrothermal and soil gas samples.

    PubMed

    Grassa, Fausto; Capasso, Giorgio; Oliveri, Ygor; Sollami, Aldo; Carreira, Paula; Rosario Carvalho, M; Marques, Jose M; Nunes, Joao C

    2010-06-01

    A continuous-flow GC/IRMS technique has been developed to analyse delta(15)N values for molecular nitrogen in gas samples. This method provides reliable results with accuracy better than 0.15 per thousand and reproducibility (1sigma) within+/-0.1 per thousand for volumes of N(2) between 1.35 (about 56 nmol) and 48.9 muL (about 2 mumol). The method was tested on magmatic and hydrothermal gases as well as on natural gas samples collected from various sites. Since the analysis of nitrogen isotope composition may be prone to atmospheric contamination mainly in samples with low N(2) concentration, we set the instrument to determine also N(2) and (36)Ar contents in a single run. In fact, based on the simultaneously determined N(2)/(36)Ar ratios and assuming that (36)Ar content in crustal and mantle-derived fluids is negligible with respect to (36)Ar concentration in the atmosphere, for each sample, the degree of atmospheric contamination can be accurately evaluated. Therefore, the measured delta(15)N values can be properly corrected for air contamination.

  4. Optical parameters of Al-doped ZnO nanorod array thin films grown via the hydrothermal method.

    PubMed

    Kim, Soaram; Kim, Min Su; Nam, Giwoong; Park, Hyunggil; Yoon, Hyunsik; Leem, Jae-Young

    2013-09-01

    ZnO seed layers were deposited onto a quartz substrate using the sol--gel method, and Al-doped ZnO (AZO) nanorod array thin films with different Al concentrations that ranged from 0 to 2.0 at. % were grown on the ZnO seed layers via the hydrothermal method. Optical parameters, including the optical band gap, the absorption coefficient, the Urbach energy, the refractive index, the dispersion parameter, and the optical conductivity, were studied to investigate the effects of Al doping on the optical properties of AZO nanorod array thin films. The optical band gaps of the ZnO and AZO nanorod array thin films were 3.206 at 0 at.%, 3.214 at 0.5 at.%, 3.226 at 1.5 at.%, and 3.268 at 2.0 at.%. The Urbach energy gradually decreased from 126 meV (0 at.%) to 70 meV (2.0 at.%) as the Al concentration was increased. The dispersion energy, the single-oscillator energy, the average oscillator wavelength, the average oscillator strength, the refractive index, and the optical conductivity of the AZO nanorod array thin films were all affected by Al doping.

  5. Synthesis and crystallographic study of Pb-Sr hydroxyapatite solid solutions by high temperature mixing method under hydrothermal conditions

    SciTech Connect

    Zhu Kongjun; Yanagisawa, Kazumichi; Shimanouchi, Rie; Onda, Ayumu; Kajiyoshi, Koji; Qiu Jinhao

    2009-06-03

    The solid solutions in the system of Pb and Sr hydroxyapatite, Sr{sub 10-x}Pb{sub x}HAp (x = 0-10), were successfully synthesized by high-temperature mixing method (HTMM) at 160 deg. C for 12 h under hydrothermal conditions. The samples were characterized by X-ray diffraction, chemical analysis and electron microscopic observation, and the site of the metal ions in the solid solutions was analyzed with the Rietveld method. The lattice constants, both a and c, of the solid solutions varied linearly with Pb content. It was found that Pb ions in the solid solutions preferentially occupied the M(2) site in the apatite structure. HTMM gives Sr-Pb HAp solid solutions much better crystallization. However, due to the formation of intermediate compound of Pb{sub 3}O{sub 2}(OH){sub 2} in the Pb(NO{sub 3}){sub 2}.4H{sub 2}O solution before mixing with (NH{sub 4}){sub 2}HPO{sub 4} solution at 160 deg. C, HTMM causes the decrease of crystallization of the samples with high Pb content.

  6. Synthesis of nanocrystalline barium-hexaferrite from nanocrystalline goethite using the hydrothermal method: Particle size evolution and magnetic properties

    SciTech Connect

    Penn, R.L.; Banfield, J.F.; Voigt, J.

    1997-03-01

    To characterize particle size/magnetic property relationships, 9 to 50 nm in diameter barium hexaferrite, BaFe{sub 12}O{sub 19} (BHF), particles were prepared using a new synthesis route. By replacing the conventional 50 to 100 nm particles of goethite with nanocrystalline goethite produced via the microwave anneal method of Knight and Sylva, nanocrystalline BHF was synthesized using the hydrothermal method. Evolution of particle size and morphology with respect to concentration and heat treatment time is reported. Hysteresis properties, including coercivity (0.2--1.0 kOe), magnetization saturation (0.1--33.4 emu/g), and magnetization remanence (0.004--22.5 emu/g) are discussed as a function of particle size. The magnetization saturation and remanence of the 7 nm particles is nearly zero, suggesting the superparamagnetic threshold size for BHF is around this size. In addition, the equilibrium morphology of BHF crystals was calculated to be truncated hexagonal prisms which was verified by experiment, and the isoelectric point, pH of 4.1, was measured for 18 nm BHF particles.

  7. Synthesis of nanocrystalline barium-hexaferrite from nanocrystalline goethite using the hydrothermal method: Particle size evolution and magnetic properties

    SciTech Connect

    Penn, R.L.; Banfield, J.F.; Voigt, J.

    1997-08-01

    To characterize particle size/magnetic property relationships, 9 to 50 nm in diameter barium hexaferrite, BaFe{sub 12}O{sub 19} (BHF), particles were prepared using a new synthesis route. By replacing the conventional 50 to 100 nm particles of goethite with nanocrystalline goethite produced via the microwave anneal method of Knight and Sylva, nanocrystalline BHF was synthesized using the hydrothermal method. Evolution of particle size and morphology with respect to concentration and heat treatment time is reported. Hysteresis properties, including coercivity (0.2--1.0 kOe), magnetization saturation (0.1--33.4 emu/g), and magnetization remanence (0.004--22.5 emu/g) are discussed as a function of particle size. The magnetization saturation and remanence of the 7 nm particles is nearly zero, suggesting the superparamagnetic threshold size for BHF is around this size. In addition, the equilibrium morphology of BHF crystals was calculated to be truncated hexagonal prisms which was verified by experiment, and the isoelectric point, pH of 4.1 was measured for 18 nm BHF particles.

  8. The Krylov accelerated SIMPLE(R) method for flow problems in industrial furnaces

    NASA Astrophysics Data System (ADS)

    Vuik, C.; Saghir, A.; Boerstoel, G. P.

    2000-08-01

    Numerical modeling of the melting and combustion process is an important tool in gaining understanding of the physical and chemical phenomena that occur in a gas- or oil-fired glass-melting furnace. The incompressible Navier-Stokes equations are used to model the gas flow in the furnace. The discrete Navier-Stokes equations are solved by the SIMPLE(R) pressure-correction method. In these applications, many SIMPLE(R) iterations are necessary to obtain an accurate solution. In this paper, Krylov accelerated versions are proposed: GCR-SIMPLE(R). The properties of these methods are investigated for a simple two-dimensional flow. Thereafter, the efficiencies of the methods are compared for three-dimensional flows in industrial glass-melting furnaces. Copyright

  9. Mapping deep-sea hydrothermal deposits with an in-loop transient electromagnetic method: Insights from 1D forward and inverse modeling

    NASA Astrophysics Data System (ADS)

    Jang, Hangilro; Kim, Hee Joon

    2015-12-01

    In transient electromagnetic (TEM) measurements, secondary fields that contain information on conductive targets such as hydrothermal mineral deposits in the seafloor can be measured in the absence of strong primary fields. A TEM system using a loop source is useful to the development of compact, autonomous instruments, which are well suited to submersible-based surveys. In this paper, we investigate the possibility of applying an in-loop TEM system to the detection of marine hydrothermal deposits through a one-dimensional modeling and inversion study. We examine step-off responses for a layered model and compare the characteristics of horizontal and vertical loop systems for detecting hydrothermal deposits. The feasibility study shows that TEM responses are very sensitive to a highly conductive layer. Time-domain target responses are larger and appear earlier in horizontal magnetic fields than in vertical ones, although the vertical field has 2-3 times larger magnitude than the horizontal one. An inverse problem is formulated with the Gauss-Newton method and solved with the damped and smoothness-constrained least-squares approach. The test example for a marine hydrothermal TEM survey demonstrated that the depth extent, conductivity and thickness of the highly conductive layer are well resolved.

  10. The Box-and-Dot Method: A Simple Strategy for Counting Significant Figures

    ERIC Educational Resources Information Center

    Stephenson, W. Kirk

    2009-01-01

    A visual method for counting significant digits is presented. This easy-to-learn (and easy-to-teach) method, designated the box-and-dot method, uses the device of "boxing" significant figures based on two simple rules, then counting the number of digits in the boxes. (Contains 4 notes.)

  11. Resazurin Microtiter Assay Plate: Simple and Inexpensive Method for Detection of Drug Resistance in Mycobacterium tuberculosis

    PubMed Central

    Palomino, Juan-Carlos; Martin, Anandi; Camacho, Mirtha; Guerra, Humberto; Swings, Jean; Portaels, Françoise

    2002-01-01

    A method for detecting multidrug-resistant Mycobacterium tuberculosis by using a reduction of resazurin is described. Eighty clinical isolates were evaluated against isoniazid and rifampin; results at 7 days were compared with those of the proportion method. Specificity and sensitivity were excellent. The method is simple, inexpensive, and rapid and might be used with other antituberculosis drugs. PMID:12121966

  12. Simple, Low-Cost Data Collection Methods for Agricultural Field Studies.

    ERIC Educational Resources Information Center

    Koenig, Richard T.; Winger, Marlon; Kitchen, Boyd

    2000-01-01

    Summarizes relatively simple and inexpensive methods for collecting data from agricultural field studies. Describes methods involving on-farm testing, crop yield measurement, quality evaluations, weed control effectiveness, plant nutrient status, and other measures. Contains 29 references illustrating how these methods were used to conduct…

  13. Simple, Low-Cost Data Collection Methods for Agricultural Field Studies.

    ERIC Educational Resources Information Center

    Koenig, Richard T.; Winger, Marlon; Kitchen, Boyd

    2000-01-01

    Summarizes relatively simple and inexpensive methods for collecting data from agricultural field studies. Describes methods involving on-farm testing, crop yield measurement, quality evaluations, weed control effectiveness, plant nutrient status, and other measures. Contains 29 references illustrating how these methods were used to conduct…

  14. A simple finite element method for non-divergence form elliptic equation

    DOE PAGES

    Mu, Lin; Ye, Xiu

    2017-03-01

    Here, we develop a simple finite element method for solving second order elliptic equations in non-divergence form by combining least squares concept with discontinuous approximations. This simple method has a symmetric and positive definite system and can be easily analyzed and implemented. We could have also used general meshes with polytopal element and hanging node in the method. We prove that our finite element solution approaches to the true solution when the mesh size approaches to zero. Numerical examples are tested that demonstrate the robustness and flexibility of the method.

  15. Development and validation of simple titrimetric method for the determination of magnesium content in esomeprazole magnesium.

    PubMed

    Haddadin, R N; Issa, A Y

    2011-07-01

    A simple and inexpensive titrimetric method for the determination of magnesium ion in esomeprazole magnesium raw material was developed and validated according to International Conference on Harmonization guidelines and the United States Pharmacopoeia. The method depends on complex formation between EDTA and magnesium ion. The method was proven to be valid, equivalent and useful as an alternative method to the current pharmacopeial methods that are based on atomic absorption spectrometry.

  16. Development and Validation of Simple Titrimetric Method for the Determination of Magnesium Content in Esomeprazole Magnesium

    PubMed Central

    Haddadin, R. N.; Issa, A. Y.

    2011-01-01

    A simple and inexpensive titrimetric method for the determination of magnesium ion in esomeprazole magnesium raw material was developed and validated according to International Conference on Harmonization guidelines and the United States Pharmacopoeia. The method depends on complex formation between EDTA and magnesium ion. The method was proven to be valid, equivalent and useful as an alternative method to the current pharmacopeial methods that are based on atomic absorption spectrometry. PMID:22707837

  17. Structural and optical study of CaF2 nanoparticles produced by a microwave-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Bezerra, Claudiane dos S.; Valerio, Mário E. G.

    2016-11-01

    CaF2 nanoparticles were synthesized by the microwave-assisted hydrothermal method. With the addition of the ethylenediamine (EDA) as chelating agent, the size of the particles was reduced. The CaF2 exhibit single phase identified for X-ray diffraction (XRD) and confirmed by Rietveld refinement. Scanning electron microscopy (SEM) images showed nanoparticles with non-uniform morphology and statistical analysis of collections of particles reviewed that the EDA decreases both the average particle size and average aspect ratio of the particles. The chemical composition of the surface of the particles was investigated by X-ray Photoelectron Spectroscopy (XPS) and the results indicated the presence of reasonable amounts of hydroxyl groups and oxygen ions in the samples produced with EDA. Radioluminescence (RL) measurements showed that both types of nanoparticles presented intrinsic scintillation emission formed by two main bands and that the CaF2 samples produced without EDA presented higher emission intensity. The broad RL band centered at approximately 293 nm is related to self-trapped exciton (STE) emission of calcium fluoride, while the band at 428 nm can be due to the presence of F centers. The STE excitation and optical band gap were measured through photoluminescent excitation spectra in the VUV range.

  18. Synthesis of TiO2 nanorods from titania and titanyl sulfate produced from ilmenite dissolution by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Wahyuningsih, S.; Ramelan, A. H.; Munifa, R. M. I.; Saputri, L. N. M. Z.; Chasanah, U.

    2016-11-01

    TiO2 powder has been synthesized through hydrolysis-condensation of titanyl sulfate solution to a starting material of TiO2 nanorods formation. This processing was conducted by the solid separation of TiO2 from ilmenite by roasting ilmenite, acidic leaching (hydrolysis), and co-precipitation (condensation). Roasting of ilmenite was carried out by the addition of Na2S at a temperature of 800°C. While the acidic leaching process was conducted by sulfuric acid at a various concentrations of 3, 3.5, 4.5, 6, and 9 M. The result shown that the solubility optimum occurs in H2SO4 6 M condition. Separation of Fe impurities of TiO2 gel from titanyl sulfate (TiOSO4) solution was done through complexation using KCNS addition. The characteristic of TiO2 obtained using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) showed good crystallinity and purity. Further treatment of the TiO2 is the formation of one-dimensional nano-size (1-D nanorods) through a hydrothermal method under basic condition NaOH 12M solution. TiO2 nanorods were confirmed by Transmission Electron Microscope (TEM) which indicated that the diameter of TiO2 nanorods was about 7.02 nm in size.

  19. Synthesis of Bi{sub 2}Se{sub 3} thermoelectric nanosheets and nanotubes through hydrothermal co-reduction method

    SciTech Connect

    Cui Hongmei; Liu Hong . E-mail: hongliu@sdu.edu.cn; Li Xia; Wang Jiyang . E-mail: jywang@icm.sdu.edu.cn; Han Feng; Zhang Xudong; Boughton, R.I.

    2004-11-01

    Bi{sub 2}Se{sub 3} nanosheets and nanotubes were prepared by a hydrothermal co-reduction method at 150, 180, 200, and 210{sup o}C. Bi{sub 2}Se{sub 3} nanosheets, nanobelts and nanotubes were obtained. The Bi{sub 2}Se{sub 3} nanoflakes are 50-500nm in width and 2-5nm in thickness. The Bi{sub 2}Se{sub 3} nanotubes are 5-10nm in diameter, 80-120nm in length, and 1.3nm in wall thickness. X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and electron diffraction were employed to characterize the products. Experimental results showed that the nanosheets and the nanotubes are hexagonal in structure with a=4.1354A and c=27.4615A. A possible formation and crystal growth mechanism of Bi{sub 2}Se{sub 3} nanostructures is proposed.

  20. Effect of lattice strain on structural and optical properties of ZnO nanorods grown by hydrothermal method

    SciTech Connect

    Gautam, Khyati Nirwal, Varun Singh; Singh, Joginder; Peta, Koteswara Rao; Bhatnagar, P. K.; Singh, Inderpreet

    2016-05-06

    In this work, we have synthesized ZnO nanorods over ZnO seeds/ITO/glass substrate by the facile hydrothermal method. ZnO seeds are grown at different temperatures ranging from 150°C to 550°C in steps of 100°C. We have studied the effect of strain on the structural and optical properties of ZnO nanorods. It was observed that the growth temperature of seed layer has an influence over the lattice strain present in the nanorods. The as synthesized nanorods were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD) and photoluminescence (PL). SEM images confirm the formation of dense arrays of vertically aligned nanorods on seeds which are grown at 350°C. In addition to this, XRD patterns reveal that these ZnO nanorods are preferentially oriented along (002) direction. The strain analysis based on the XRD results reveals that the minimum value of strain is obtained at 350°C which is attributed to the improved crystalline quality of the interface of seed layer and nanorods leading to their c-axis alignment and enhancement of ultraviolet emission as observed in the PL spectra.

  1. Structural and room temperature ferromagnetic properties of Ni doped ZnO nanoparticles via low-temperature hydrothermal method

    NASA Astrophysics Data System (ADS)

    Xu, Kun; Liu, Changzhen; Chen, Rui; Fang, Xiaoxiang; Wu, Xiuling; Liu, Jie

    2016-12-01

    A series of Zn1-xNixO (x=0, 1%, 3%, 5%) nanoparticles have been synthesized via a low-temperature hydrothermal method. Influence of Ni doping concentration on the structure, morphology, optical properties and magnetism of the samples was investigated by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-vis spectrophotometer and vibrating sample magnetometer instruments. The results show that the undoped and doped ZnO nanoparticles are both hexagonal wurtzite structures. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The images of SEM reveal that the structure of pure ZnO and Ni doped samples are nanoparticles which intended to form flakes with thickness of few nanometers, being overlain with each one to develop the network with some pores and voids. Based on the ultraviolet-visible (UV-vis) spectroscopy analysis, it indicates that the band gap energy decreases with the increasing concentration of Ni. Furthermore, The Ni doped ZnO samples didn't exhibit higher ultraviolet-light-driven photocatalytic activity compared to the undoped ZnO sample. Vibrating sample magnetometer was used for the magnetic property investigations, and the result indicates that room temperature ferromagnetism property of 3% Ni doped sample is attributed to oxygen vacancy and interaction between doped ions.

  2. Photocatalytic reduction of NO with NH3 using Si-doped TiO2 prepared by hydrothermal method.

    PubMed

    Jin, Ruiben; Wu, Zhongbiao; Liu, Yue; Jiang, Boqiong; Wang, Haiqiang

    2009-01-15

    A series of Si-doped TiO2 (Si/TiO2) photocatalysts supported on woven glass fabric were prepared by hydrothermal method for photocatalytic reduction of NO with NH3. The photocatalytic activity tests were carried out in a continuous Pyrex reactor with the flow rate of 2000mL/min under UV irradiation (luminous flux: 1.1x10(4)lm, irradiated catalyst area: 160cm2). The photocatalysts were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectrophotometer, transmission electron microscopy (TEM), photoluminescence (PL) and temperature-programmed desorption (TPD). The experiment results showed that NO conversion on Si/TiO2 at 323K could exceed 60%, which was about 50% higher than that on Degussa P25 and pure TiO2. With the doping of Si, photocatalysts with smaller crystal size, larger surface area and larger pore volume were obtained. It was also found that Ti-O-Si bands were formed on the surface of Si/TiO2 and that the surface hydroxyl concentration was greatly increased. As a result, total acidity and NH3 chemisorption amount were enhanced for Si/TiO2 leading to its photocatalytic activity improvement.

  3. Selective synthesis of vitamin K3 over mesoporous NbSBA-15 catalysts synthesized by an efficient hydrothermal method.

    PubMed

    Selvaraj, M; Park, D-W; Kim, I; Kawi, S; Ha, C S

    2012-08-28

    Well hexagonally ordered NbSBA-15 catalysts synthesized by an efficient hydrothermal method were used, for the first time, for the selective synthesis of vitamin K(3) by liquid-phase oxidation of 2-methyl-1-naphthol (2MN1-OH) under various reaction conditions. The recyclable NbSBA-15 catalysts were also reused to find their catalytic activities. To investigate the leaching of non-framework niobium species on the surface of silica networks, the results of original and recyclable NbSBA-15 catalysts were correlated and compared. To find an optimum condition for the selective synthesis of vitamin K(3), the washed NbSBA-15(2.2pH) was extensively used in this reaction with various reaction parameters such as temperature, time and ratios of reactant (2M1N-OH to H(2)O(2)), and the obtained results were also demonstrated. Additionally, the liquid-phase oxidation of 2M1N-OH was carried out with different solvents to find the best solvent with a good catalytic activity. Based on the all catalytic studies, the vitamin K(3) selectivity (97.3%) is higher in NbSBA-15(2.2pH) than that of other NbSBA-15 catalysts, and the NbSBA-15(2.2pH) is found to be a highly active and eco-friendly heterogeneous catalyst for the selective synthesis of vitamin K(3).

  4. Electrochemical properties of Li2 FeSiO4 /C nanocomposites prepared by sol-gel and hydrothermal methods

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Jayakumar, O. D.; Naik, Vaman M.; Nazri, Gholam A.; Naik, Ratna

    Li2FeSiO4 is considered as potential cathode material for next generation lithium ion batteries because of its high specific theoretical capacity, low cost, and safety. However, it suffers from poor electronic conductivity and slow lithium ion diffusion in the solid phase. To address these issues, we have studied mesoporous Li2FeSiO4/C composites synthesized by sol-gel (SG) and hydrothermal (HT) methods using tri-block copolymer (P123) as carbon source and structure directing agent. The structure and morphology of the composites were characterized by XRD, SEM and TEM and the surface area and pore size distribution were measured by using N2 adsorption/desorption. Galvanostatic cycling, electrochemical impedance spectroscopy, and cyclic voltammetry were used to evaluate the electrochemical performance of the Li2FeSiO4/C composites. The Li2FeSiO4/C (HT) composites show a superior electrochemical performance compared to Li2FeSiO4/C (SG). At C/30 rate, the discharge capacity of Li2FeSiO4/C (HT) reached ~276 mAh/g in the 1.5-4.6 V window and shows better rate capability and stability at high rates. We attribute the improved electrochemical performance of Li2FeSiO4/C (HT) to its large surface area and reduced particle size. The details of the study will be presented.

  5. Adsorption of Pb(II) and Cd(II) from aqueous solutions using titanate nanotubes prepared via hydrothermal method.

    PubMed

    Xiong, Lin; Chen, Cheng; Chen, Qing; Ni, Jinren

    2011-05-30

    Titanate nanotubes (TNs) with specific surface areas of 272.31 m(2)g(-1) and pore volumes of 1.264 cm(3)g(-1) were synthesized by alkaline hydrothermal method. The TNs were investigated as adsorbents for the removal of Pb(II) and Cd(II) from aqueous solutions. The FT-IR analysis indicated that Pb(II) and Cd(II) adsorption were mainly ascribed to the hydroxyl groups in the TNs. Batch experiments were conducted by varying contact time, pH and adsorbent dosage. It was shown that the initial uptake of each metal ion was very fast in the first 5 min, and adsorption equilibrium was reached after 180 min. The adsorption of Pb(II) and Cd(II) were found to be maximum at pH in the range of 5.0-6.0. The adsorption kinetics of both metal ions followed the pseudo-second-order model. Equilibrium data were best fitted with the Langmuir isotherm model, and the maximum adsorption capacities of Pb(II) and Cd(II) were determined to be 520.83 and 238.61 mg g(-1), respectively. Moreover, more than 80% of Pb(II) and 85% of Cd(II) adsorbed onto TNs can be desorbed with 0.1M HCl after 3h. Thus, TNs were considered to be effective and promising materials for the removal of both Pb(II) and Cd(II) from wastewater.

  6. Synthesis of nano-Se/bamboo charcoal composites via hydrothermal method and their application on remaining fresh of cutting roses.

    PubMed

    Tang, Ping; Yu, Weiping; Jiang, Kunpeng; Liao, Lei; Qin, Aimiao

    2013-02-01

    Nano-Se/bamboo charcoal (BC) composites were prepared successfully by hydrothermal method. The composites were characterized by SEM, XRD, Atomic Absorption Spectroscopy (AAS) and Atomic fluorescence spectroscopy (AFS) analysis. The effects of the synthesized conditions on the morphologies of Se particles on BC were investigated. The results showed that the reaction time, the adding order of reagents and the concentration of hydrazine have much influence on the formation of nano-Se/BC composites. The application of composites on the keeping fresh of cutting rose flowers was also studied, the experiment results indicate that Nano-Se/BC composites have better effect on the keeping fresh of cutting rose flowers than single BC, Nano-Se, distilled water and commercial "flower food" nutrient solution, the florescence of cutting rose flowers is distinctly extend by Nano-Se/BC composites up to 48 and 24 days in winter and summer respectively. "Synergy effects" and "Delayed release capsule effects" were used to explain the mechanism of Nano-Se/BC composites on the keeping fresh of cutting rose flowers.

  7. Ultrafast hydrothermal synthesis of high quality magnetic core phenol-formaldehyde shell composite microspheres using the microwave method.

    PubMed

    You, Li-Jun; Xu, Shuai; Ma, Wan-Fu; Li, Dian; Zhang, Yu-Ting; Guo, Jia; Hu, Jack J; Wang, Chang-Chun

    2012-07-17

    An ultrafast, facile, and efficient microwave hydrothermal approach was designed to fabricate magnetic Fe(3)O(4)/phenol-formaldehyde (PF) core-shell microspheres for the first time. The structure of the Fe(3)O(4)/PF core-shell microspheres could be well controlled by the in situ polycondensation of phenol and formaldehyde with magnetic Fe(3)O(4) clusters as the seeds in an aqueous solution without any surfactants. The effect of synthetic parameters, such as the feeding amounts of phenol, the dosages of formaldehyde, the reaction temperatures, and the microwave heating time, on the morphologies and sizes of the Fe(3)O(4)/PF microspheres were investigated in details. The phenol-formaldehyde shell is found to be evenly coated on Fe(3)O(4) clusters within 10 min of the irradiation. The as-prepared microspheres were highly uniform in morphology, and the method was found to allow the shell thickness to be finely controlled in the range of 10-200 nm. The properties of the composite microspheres were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetic analysis (TGA), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The as-prepared Fe(3)O(4)/PF microspheres were monodisperse and highly dispersible in water, ethanol, N,N-dimethyformamide, and acetone, a beneficial quality for the further functionalization and applications of the Fe(3)O(4)/PF microspheres.

  8. Synthesis of N-acetyl-L-cysteine-capped ZnCdSe quantum dots via hydrothermal method and their characterization

    PubMed Central

    Gao, Fang; Liu, Yuying; Fan, Yao; Zhao, Dan

    2014-01-01

    Compared with the most studied green-red emitting (530–650 nm) quantum dots (QDs), the preparation of short-wavelength-emitting QDs remains difficult. Besides, one of the representative short-wavelength QDs materials, ZnCdSe, has a shortcoming of high content of toxic cadmium metal. In this paper, we report the synthesis of high-quality water-soluble ZnCdSe QDs via optimized one-step hydrothermal method with a new thiol as ligand, within a short time of 65 min. The emission wavelength of prepared QDs is tunable in the range of 425–540 nm by merely controlling the molar ratio of Cd:Zn or Se:Zn, and the quantum yield reaches 35%. More importantly, the maximum Cd:Zn molar ratio has been reduced to 0.04:1.0, much lower than that reported in the literature (0.5:1.0), resulting in excellent biological compatibility of prepared QDs and thus their promising applications in biological fields. Moreover, the transmission electron microscopy was employed to examine the effect of Cd:Zn ratio on the size of prepared ZnCdSe QDs, which were also characterized by x-ray photoelectron spectroscopy and electron diffraction spectroscopy. PMID:27877713

  9. Adsorption and photocatalytic degradation of methylene blue using high surface area titanate nanotubes (TNT) synthesized via hydrothermal method

    NASA Astrophysics Data System (ADS)

    Subramaniam, M. N.; Goh, P. S.; Abdullah, N.; Lau, W. J.; Ng, B. C.; Ismail, A. F.

    2017-06-01

    Removal of methylene blue (MB) via adsorption and photocatalysis using titanate nanotubes (TNTs) with different surface areas were investigated and compared to commercial titanium dioxide (TiO2) P25 Degussa nanoparticles. The TNTs with surface area ranging from 20 m2/g to 200 m2/g were synthesized via hydrothermal method with different reaction times. TEM imaging confirmed the tubular structure of TNT while XRD spectra indicated all TNTs exhibited anatase crystallinity. Batch adsorption rate showed linearity with surface properties of TNTs, where materials with higher surface area showed higher adsorption rate. The highest MB adsorption (70%) was achieved by TNT24 in 60 min whereas commercial TiO2 exhibited the lowest adsorption of only 10% after 240 min. Adsorption isotherm studies indicated that adsorption using TNT is better fitted into Langmuir adsorption isotherm than Freundlich isotherm model. Furthermore, TNT24 was able to perform up to 90% removal of MB within 120 min, demonstrating performance that is 2-fold better compared to commercial TiO2. The high surface area and surface Bronsted acidity are the main reasons for the improvement in MB removal performance exhibited by TNT24. The improvement in surface acidity enhanced the adsorption properties of all the nanotubes prepared in this study.

  10. Preparation and characterization of PVA-I complex doped mesoporous TiO2 by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Shi, Qian; Jiang, Caiyun; Wang, Yuping; Yang, Weiben; Yang, Chun

    2013-05-01

    Polyvinyl alcohol [PVA]-iodine complex doped mesoporous TiO2 (PIT) and iodine doped (IT) catalysts were prepared by hydrothermal method, using tetrabutyl titanate as precursor, potassium iodate and iodine as iodine sources. The as-prepared PIT and IT catalysts were characterized by UV-vis, XRD, FESEM, BET, TG/DTA, XPS and photoluminescence (PL) spectroscopy. Production of rad OH radicals on the surface of photocatalyst was detected by the PL technique using terephthalic acid as a probe molecule. The influences of calcinated temperature on the structure and properties of the catalysts were investigated. The photocatalytic activity of catalysts was evaluated through photocatalytic decolorization of methylene blue (MB) aqueous solution. The results showed that PIT samples were anatase mesoporous TiO2 and their iodine content and mesoporous structure were influenced by calcinated temperature. Particle size of PIT samples was smaller than that of IT as a result of the PVA skeleton and regular structure. Because of the complexation of iodine and PVA, thermostability of iodine is improved and the amount of iodine in PIT calcinated at 200 °C (PIT-200) is higher than that of IT calcinated at same temperature. Light absorption range and intensity of PIT-200 has been greatly improved due to the synergy of iodine and carbon. The efficiency of photocatalysis for MB is greatly improved with TiO2 modified by PVA-I complex under simulated sun light irradiation.

  11. Comparison Of Direct Simple Shear Confinement Methods On Clay And Silt Specimens

    DTIC Science & Technology

    2011-12-20

    12-2011 Master’s Thesis JUN 2011 - DEC 2011 Comparison of Direct Simple Shear Confinement Methods on Clay and Silt Specimens N00244-09-G-049 Seth...system for direct simple shear tests. Tests were performed on samples of a high plasticity clay from the Gulf of Mexico, a low plasticity organic...silt from Rhode Island, and a low plasticity sensitive clay from Portland, Maine. All soils were tested using both confinement types, with the only

  12. Method for estimating the morphological significance of simple forms of crystals from X-ray data

    SciTech Connect

    Treivus, E. B.

    2010-09-15

    When developing V.I. Mikheev and I.I. Shafranovskii's method for estimating the morphological significance of faces of different simple forms from X-ray reflection intensities, a way to approximately evaluate the morphological significance of simple forms on crystals from the structure amplitudes of the corresponding atomic planes is proposed. The potential for this approach is demonstrated by the examples of marcasite and zircon.

  13. Synthesis of BiFeO{sub 3} thin films on single-terminated Nb : SrTiO{sub 3} (111) substrates by intermittent microwave assisted hydrothermal method

    SciTech Connect

    Velasco-Davalos, Ivan; Ambriz-Vargas, Fabian; Kolhatkar, Gitanjali; Thomas, Reji E-mail: reji.thomas@emt.inrs.ca; Ruediger, Andreas E-mail: reji.thomas@emt.inrs.ca

    2016-06-15

    We report on a simple and fast procedure to create arrays of atomically flat terraces on single crystal SrTiO{sub 3} (111) substrates and the deposition of ferroelectric BiFeO{sub 3} thin films on such single-terminated surfaces. A microwave-assisted hydrothermal method in deionized water and ammonia solution selectively removes either (SrO{sub 3}){sup 4−} or Ti{sup 4+} layers to ensure the same chemical termination on all terraces. Measured step heights of 0.225 nm (d{sub 111}) and uniform contrast in the phase image of the terraces confirm the single termination in pure and Nb doped SrTiO{sub 3} single crystal substrates. Multiferroic BiFeO{sub 3} thin films were then deposited by the same microwave assisted hydrothermal process on Nb : SrTiO{sub 3} (111) substrates. Bi(NO{sub 3}){sub 3} and Fe(NO{sub 3}){sub 3} along with KOH served as the precursors solution. Ferroelectric behavior of the BiFeO{sub 3} films on Nb : SrTiO{sub 3} (100) substrates was verified by piezoresponse force microscopy.

  14. Evaluation of the effectiveness of simple nuclei-segmentation methods on Caenorhabditis elegans embryogenesis images.

    PubMed

    Azuma, Yusuke; Onami, Shuichi

    2013-10-04

    For the analysis of spatio-temporal dynamics, various automated processing methods have been developed for nuclei segmentation. These methods tend to be complex for segmentation of images with crowded nuclei, preventing the simple reapplication of the methods to other problems. Thus, it is useful to evaluate the ability of simple methods to segment images with various degrees of crowded nuclei. Here, we selected six simple methods from various watershed based and local maxima detection based methods that are frequently used for nuclei segmentation, and evaluated their segmentation accuracy for each developmental stage of the Caenorhabditis elegans. We included a 4D noise filter, in addition to 2D and 3D noise filters, as a pre-processing step to evaluate the potential of simple methods as widely as possible. By applying the methods to image data between the 50- to 500-cell developmental stages at 50-cell intervals, the error rate for nuclei detection could be reduced to ≤ 2.1% at every stage until the 350-cell stage. The fractions of total errors throughout the stages could be reduced to ≤ 2.4%. The error rates improved at most of the stages and the total errors improved when a 4D noise filter was used. The methods with the least errors were two watershed-based methods with 4D noise filters. For all the other methods, the error rate and the fraction of errors could be reduced to ≤ 4.2% and ≤ 4.1%, respectively. The minimum error rate for each stage between the 400- to 500-cell stages ranged from 6.0% to 8.4%. However, similarities between the computational and manual segmentations measured by volume overlap and Hausdorff distance were not good. The methods were also applied to Drosophila and zebrafish embryos and found to be effective. The simple segmentation methods were found to be useful for detecting nuclei until the 350-cell stage, but not very useful after the 400-cell stage. The incorporation of a 4D noise filter to the simple methods could improve

  15. Fast preparation of LiFePO4 nanoparticles for lithium batteries by microwave-assisted hydrothermal method.

    PubMed

    Yang, Gang; Ji, Hongmei; Liu, Haidong; Huo, Kaifu; Fu, Jijiang; Chu, Paul K

    2010-02-01

    Nanomaterial for lithium batteries can decrease mechanical strain upon lithium intercalation/ deintercalation from lattice, and lead to high rate capability. The currently available microwave technology permits the development and implantation of a temperature-controlled microwave-assisted hydrothermal synthesis (TCMH) of nano-sized cathode material for lithium batteries. Unlike in previous reported traditional hydrothermal synthesis of cathode material LiFePO4, the pure phase of LiFePO4 can be simply and rapidly synthesized for 5 minutes in water under hydrothermal treatment with microwave irradiation. The homogeneous effects induced by microwave irradiation could create a uniform seeding condition. The colloid precursor Li3PO4 plays the key role to be the nucleation center for the new phase while the formation energy for LiFePO4 would be decreased during the following microwave irradiation. The as-prepared pristine LiFePO4 without carbon coating are characterized by X-ray diffraction, Raman, scanning and transmission electron microscopy, and tested as the cathode in lithium batteries. The particle sizes of pristine LiFePO4 are dependent on hydrothermal and microwave-assisted hydrothermal condition and the electrochemical performance are relatively determined.

  16. Photocatalytic properties of h-WO3 nanoparticles obtained by annealing and h-WO3 nanorods prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Boyadjiev, Stefan I.; Nagy-Kovács, Teodóra; Lukács, István; Szilágyi, Imre M.

    2016-03-01

    In the present study, two different methods for preparing hexagonal WO3 (h-WO3) photocatalysts were used - controlled thermal decomposition and hydrothermal synthesis. WO3 nanoparticles with hexagonal structure were obtained by annealing (NH4)xWO3-y at 500 °C in air. WO3 nanorods were prepared by a hydrothermal method using sodium tungstate Na2WO4, HCl, (COOH)2 and NaSO4 precursors at 200 °C. The formation, morphology, structure and composition of the as-prepared nanoparticles and nanorods were studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX). The photocatalytic activity of the h-WO3 nanoparticles and nanorods was studied by decomposing methyl orange in aqueous solution under UV light irradiation.

  17. Propeller design IV : a simple method for determining the strength of propellers

    NASA Technical Reports Server (NTRS)

    Weick, Fred E

    1926-01-01

    The object of this report, the last of a series of four on propeller design, is to describe a simple method for determining whether the strength of a propeller of a standard form is sufficient for safe operation. An approximate method of stress analysis is also given.

  18. A Simple Microsoft Excel Method to Predict Antibiotic Outbreaks and Underutilization.

    PubMed

    Miglis, Cristina; Rhodes, Nathaniel J; Avedissian, Sean N; Zembower, Teresa R; Postelnick, Michael; Wunderink, Richard G; Sutton, Sarah H; Scheetz, Marc H

    2017-07-01

    Benchmarking strategies are needed to promote the appropriate use of antibiotics. We have adapted a simple regressive method in Microsoft Excel that is easily implementable and creates predictive indices. This method trends consumption over time and can identify periods of over- and underuse at the hospital level. Infect Control Hosp Epidemiol 2017;38:860-862.

  19. A simple method of calculating lower-bound limit loads for axisymmetric thin shells

    SciTech Connect

    Boyle, J.T.; Hamilton, R.; Shi, J.; Mackenzie, D.

    1997-05-01

    In this paper, a simple method for calculating lower-bound limit loads for shells is presented, based on Ilyushin`s and Ivanov`s generalized yield criterion, respectively, and using the elastic compensation procedure. Several examples, including torispherical and conical ends, radial nozzles, and a skirted vessel, are examined using this method. The results are compared with previously published results.

  20. The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

    ERIC Educational Resources Information Center

    Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

    2011-01-01

    The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

  1. A simple agar plate method, using micro-algae, for herbicide bio-assay or detection.

    PubMed

    Wright, S J

    1975-07-01

    A simple, inexpensive method is described for the bio-assay of herbicides using micro-algae growing on agar plates. A result is obtainable in 2 days and the method is suitable for biodetection of herbicide residues, or toxicity studies on soil or aquatic pollutants.

  2. A Simple Method for the Consecutive Determination of Protonation Constants through Evaluation of Formation Curves

    ERIC Educational Resources Information Center

    Hurek, Jozef; Nackiewicz, Joanna

    2013-01-01

    A simple method is presented for the consecutive determination of protonation constants of polyprotic acids based on their formation curves. The procedure is based on generally known equations that describe dissociation equilibria. It has been demonstrated through simulation that the values obtained through the proposed method are sufficiently…

  3. A Simple Method for the Consecutive Determination of Protonation Constants through Evaluation of Formation Curves

    ERIC Educational Resources Information Center

    Hurek, Jozef; Nackiewicz, Joanna

    2013-01-01

    A simple method is presented for the consecutive determination of protonation constants of polyprotic acids based on their formation curves. The procedure is based on generally known equations that describe dissociation equilibria. It has been demonstrated through simulation that the values obtained through the proposed method are sufficiently…

  4. A simple method for cultivating freshwater copepods used in biological control of Aedes aegypti.

    PubMed

    Suarez, M F; Marten, G G; Clark, G G

    1992-12-01

    A simple method for indoor and outdoor cultivation of Mesocyclops aspericornis, Macrocyclops albidus and Mesocyclops n. sp. copepods is presented. This method utilizes Chilomonas sp., Paramecium caudatum and fresh lettuce as food sources for copepod cultures. Steps for initiating and maintaining copepod cultures are provided.

  5. A simple method for ex vivo evaluation of biomaterial interaction with blood platelets.

    PubMed

    Mantovani, F; Marconi, W; Caprino, L; Goglia, G; Togna, G

    1980-09-01

    The process of thrombus formation, as a consequence of the interaction of artificial surfaces with blood, is related to the activation of blood platelets. A simple ex vivo method, which is suitable for the evaluation of the platelet-surface interaction is described. This method has been used to compare the haemocompatibility of several artificial materials, including nylon-6, Silastic and pyrolytic carbon.

  6. Hydrothermal reactivity of saponite.

    USGS Publications Warehouse

    Whitney, G.

    1983-01-01

    The nature and extent of the reactions of synthetic Fe-free saponite have been investigated under experimental hydrothermal conditions as a first step towards understanding saponite reactivity under relatively simple conditions. Saponite crystallizes from amorphous gel of ideal saponite composition within 7 days at 300o-550oC under P = 1 kbar. Reactions subsequent to this initial crystallization depend on reaction T and interlayer cations. Saponite is found to react hydrothermally, over a period of 200 days, at T down to 400oC, at least 150oC lower than previously reported, but showed no signs of reaction below 400oC. At 450oC, a mixture of talc/saponite and saponite/phlogopite clays forms from K-saponite via intracrystalline layer transformations, while above 450oC the initial K-saponite dissolves, with talc and phlogopite forming as discrete phases. After 200 days reactions at 400-450oC were not complete, so that given sufficient time to reach equilibrium, a lower hydrothermal stability limit for saponite is possible. Further study of the Fe-bearing saponite system will be required before experimental results can be applied to natural systems.-D.F.B.

  7. Thermochemical parameters of minerals from oxygen-buffered hydrothermal equilibrium data: Method, application to annite and almandine

    USGS Publications Warehouse

    Zen, E.-A.

    1973-01-01

    Reversed univariant hydrothermal phase-equilibrium reactions, in which a redox reaction occurs and is controlled by oxygen buffers, can be used to extract thermochemical data on minerals. The dominant gaseous species present, even for relatively oxidizing buffers such as the QFM buffer, are H2O and H2; the main problem is to calculate the chemical potentials of these components in a binary mixture. The mixing of these two species in the gas phase was assumed by Eugster and Wones (1962) to be ideal; this assumption allows calculation of the chemical potentials of the two components in a binary gas mixture, using data in the literature. A simple-mixture model of nonideal mixing, such as that proposed by Shaw (1967), can also be combined with the equations of state for oxygen buffers to permit derivation of the chemical potentials of the two components. The two mixing models yield closely comparable results for the more oxidizing buffers such as the QFM buffer. For reducing buffers such as IQF, the nonideal-mixing correction can be significant and the Shaw model is better. The procedure of calculation of mineralogical thermochemical data, in reactions where hydrogen and H2O simultaneously appear, is applied to the experimental data on annite, given by Wones et al. (1971), and on almandine, given by Hsu (1968). For annite the results are: Standard entropy of formation from the elements, Sf0 (298, 1)=-283.35??2.2 gb/gf, S0 (298, 1) =+92.5 gb/gf. Gf0 (298, 1)=-1148.2??6 kcal, and Hf0 (298, 1)=-1232.7??7 kcal. For almandine, the calculation takes into account the mutual solution of FeAl2O4 (Hc) in magnetite and of Fe3O4 (Mt) in hercynite and the temperature dependence of this solid solution, as given by Turnock and Eugster (1962); the calculations assume a regular-solution model for this binary spinel system. The standard entropy of formation of almandine, Sf,A0 (298, 1) is -272.33??3 gb/gf. The third law entropy, S0 (298, 1) is +68.3??3 gb/gf, a value much less than the

  8. Obtaining titanium dioxide nanoparticles with spherical shape and antimicrobial properties using M. citrifolia leaves extract by hydrothermal method.

    PubMed

    M, Sundrarajan; K, Bama; M, Bhavani; S, Jegatheeswaran; S, Ambika; A, Sangili; P, Nithya; R, Sumathi

    2017-06-01

    In this work, we synthesized titanium dioxide (TiO2) nanoparticles using leaf extract of Morinda citrifolia (M. citrifolia) by the advanced hydrothermal method. The synthesized TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Fourier transmission infrared (FT-IR), Ultraviolet-visible diffuse reflectance (UV-Vis DRS), Ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM with EDX) techniques. The XRD major peak at 27.3° corresponds to the (110) lattice plane of tetragonal rutile TiO2 phase and average crystalline size of nanoparticles is 10nm. The FT-IR result confirmed that TiO2 nanoparticles and the presences of very few amount of anthraquinone and phenolic compounds of the leaf extract. The obtained nanoparticles were also characterized by UV-Vis DRS absorption spectroscopy and an intense band at 423nm clearly reveals the formation of nanoparticles. SEM images with EDX spectra clearly reveal the size of the nanoparticles, between 15 and 19nm in excellent quasi-spherical shape, by virtue of stabilization (capping) agent. The presence of elements-titanium and oxygen was verified with EDX spectrum. Furthermore, the inhibitory activity of green synthesized TiO2 nanoparticles was tested against human pathogens like Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger by the agar well-diffusion method. The TiO2 nanoparticles exhibited superior antimicrobial activity against Gram-positive bacteria, demonstrating their antimicrobial value against pathogenic diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A simple and direct method for generating travelling wave solutions for nonlinear equations

    SciTech Connect

    Bazeia, D. Das, Ashok; Silva, A.

    2008-05-15

    We propose a simple and direct method for generating travelling wave solutions for nonlinear integrable equations. We illustrate how nontrivial solutions for the KdV, the mKdV and the Boussinesq equations can be obtained from simple solutions of linear equations. We describe how using this method, a soliton solution of the KdV equation can yield soliton solutions for the mKdV as well as the Boussinesq equations. Similarly, starting with cnoidal solutions of the KdV equation, we can obtain the corresponding solutions for the mKdV as well as the Boussinesq equations. Simple solutions of linear equations can also lead to cnoidal solutions of nonlinear systems. Finally, we propose and solve some new families of KdV equations and show how soliton solutions are also obtained for the higher order equations of the KdV hierarchy using this method.

  10. Exploration strategies for hydrothermal deposits.

    PubMed

    Horn, R A

    1996-01-01

    With unlimited money the most certain strategy for finding most hydrothermal metal deposits would be by drilling to 5000 m at 50 m spacing. However, the cost would far outweigh the benefit of the discoveries. Geological knowledge and exploration techniques may be used to obtain the greatest benefit for minimum cost, and to concentrate human and material resources in the most economic way in areas with the highest probability of discovery. This paper reviews the economic theory of exploration based on expected value, and the application of geological concepts and exploration techniques to exploration for hydrothermal deposits. Exploration techniques for hydrothermal-systems on Mars would include geochemistry and particularly passive geophysical methods.

  11. Simple, reliable, and nondestructive method for the measurement of vacuum pressure without specialized equipment.

    PubMed

    Yuan, Jin-Peng; Ji, Zhong-Hua; Zhao, Yan-Ting; Chang, Xue-Fang; Xiao, Lian-Tuan; Jia, Suo-Tang

    2013-09-01

    We present a simple, reliable, and nondestructive method for the measurement of vacuum pressure in a magneto-optical trap. The vacuum pressure is verified to be proportional to the collision rate constant between cold atoms and the background gas with a coefficient k, which can be calculated by means of the simple ideal gas law. The rate constant for loss due to collisions with all background gases can be derived from the total collision loss rate by a series of loading curves of cold atoms under different trapping laser intensities. The presented method is also applicable for other cold atomic systems and meets the miniaturization requirement of commercial applications.

  12. A Simple Method for Improving Torsion Optimization of Ligand Molecules in Receptor Binding Sites.

    PubMed

    Che, Jianwei

    2005-07-01

    A simple but effective method is introduced for optimizing ligand molecules in torsion space within receptor binding sites. The algorithm makes use of geometric constraints of ligand molecules to search for energetically favorable conformations. It is applied to a conjugate gradient (CG) method as an example. During conformational energy optimization, new line search directions are modified according to the spatial span of rotational groups in ligand molecules. Significant improvements were observed in terms of the abilities both to recover global optimal structures and to obtain lower energy ensembles. This simple algorithm allows rapid implementation and can be incorporated into other conformational energy optimization techniques.

  13. A simple method for displaying cine images on web-based teaching files.

    PubMed

    Yam, Chun-Shan; Levine, Deborah; Nishino, Mizuki; Sitek, Arkadiusz; Larson, Michael

    2005-02-01

    Our objective was to develop a simple method for displaying dynamic cine images on Web-based teaching files. We developed a simple method for displaying cine images on Web-based teaching files using an open-source utility, the Java applet. This interactive utility offers improved 3D visualizations compared with the traditional approach using thumbnail and static images. Because Java is a built-in component of common Web browsers and computer systems, no other software was required. We have used this applet successfully for more than 2 years in our Web-based teaching system, including in our teaching files and on our case-of-the-week page.

  14. Selected simple methods of plant cell wall histochemistry and staining for light microscopy.

    PubMed

    Soukup, Aleš

    2014-01-01

    Histochemical methods allow for identification and localization of various components within the tissue. Such information on the spatial heterogeneity is not available with biochemical methods. However, there is limitation of the specificity of such detection in context of complex tissue, which is important to consider, and interpretations of the results should regard suitable control treatments if possible. Hereby we present set of selected simple staining and histochemical methods with comments based on our laboratory experience.

  15. Modelling of Thermal Advective Reactive Flow in Hydrothermal Mineral Systems Using an Implicit Time-stepped Finite Element Method.

    NASA Astrophysics Data System (ADS)

    Hornby, P. G.

    2005-12-01

    Understanding chemical and thermal processes taking place in hydrothermal mineral deposition systems could well be a key to unlocking new mineral reserves through improved targeting of exploration efforts. To aid in this understanding it is very helpful to be able to model such processes with sufficient fidelity to test process hypotheses. To gain understanding, it is often sufficient to obtain semi-quantitative results that model the broad aspects of the complex set of thermal and chemical effects taking place in hydrothermal systems. For example, it is often sufficient to gain an understanding of where thermal, geometric and chemical factors converge to precipitate gold (say) without being perfectly precise about how much gold is precipitated. The traditional approach is to use incompressible Darcy flow together with the Boussinesq approximation. From the flow field, the heat equation is used to advect-conduct the heat. The flow field is also used to transport solutes by solving an advection-dispersion-diffusion equation. The reactions in the fluid and between fluid and rock act as source terms for these advection-dispersion equations. Many existing modelling systems that are used for simulating such systems use explicit time marching schemes and finite differences. The disadvantage of this approach is the need to work on rectilinear grids and the number of time steps required by the Courant condition in the solute transport step. The second factor can be particularly significant if the chemical system is complex, requiring (at a minimum) an equilibrium calculation at each grid point at each time step. In the approach we describe, we use finite elements rather than finite differences, and the pressure, heat and advection-dispersion equations are solved implicitly. The general idea is to put unconditional numerical stability of the time integration first, and let accuracy assume a secondary role. It is in this sense that the method is semi-quantiative. However

  16. Influence of External Gaseous Environments on the Electrical Properties of ZnO Nanostructures Obtained by a Hydrothermal Method

    PubMed Central

    Procek, Marcin; Pustelny, Tadeusz; Stolarczyk, Agnieszka

    2016-01-01

    This paper deals with experimental investigations of ZnO nanostructures, consisting of a mixture of nanoparticles and nanowires, obtained by the chemical (hydrothermal) method. The influences of both oxidizing (NO2) and reducing gases (H2, NH3), as well as relative humidity (RH) on the physical and chemical properties of ZnO nanostructures were tested. Carrier gas effect on the structure interaction with gases was also tested; experiments were conducted in air and nitrogen (N2) atmospheres. The effect of investigated gases on the resistance of the ZnO nanostructures was tested over a wide range of concentrations at room temperature (RT) and at 200 °C. The impact of near- ultraviolet (UV) excitation (λ = 390 nm) at RT was also studied. These investigations indicated a high response of ZnO nanostructures to small concentrations of NO2. The structure responses to 1 ppm of NO2 amounted to about: 600% in N2/230% in air at 200 °C (in dark conditions) and 430% in N2/340% in air at RT (with UV excitation). The response of the structure to the effect of NO2 at 200 °C is more than 105 times greater than the response to NH3, and more than 106 times greater than that to H2 in the relation of 1 ppm. Thus the selectivity of the structure for NO2 is very good. What is more, the selectivity to NO2 at RT with UV excitation increases in comparison at elevated temperature. This paper presents a great potential for practical applications of ZnO nanostructures (including nanoparticles) in resistive NO2 sensors. PMID:28335355

  17. Characterization and magnetic properties of SrTi1-xNixO3 nanoparticles prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Karaphun, Attaphol; Hunpratub, Sitchai; Phokha, Sumalin; Putjuso, Thanin; Swatsitang, Ekaphan.

    2017-01-01

    SrTi1-xNixO3 (x=0, 0.05, 0.10 and 0.15) nanoparticles were prepared by the hydrothermal method. All as-prepared samples were annealed at 800 °C for 3 h in argon to study the annealing effect on their magnetic properties. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray absorption near edge spectroscopy (XANES), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM) were used to study the crystalline structure, morphology, oxidation state and magnetic properties of samples. XRD results indicate a cubic perovskite structure of all samples with the impurity phase of SrCO3 in all as-prepared samples and Ni metal in annealed samples of x=0.10 and 0.15. SEM and TEM images confirmed a cubic shape for all samples with decreasing average particle sizes from 136.8±4.7 to 126.2±6.9 nm for annealed samples upon Ni doping. XANES results revealed the existence of Ni metal in sample of x=0.05 with the oxidation state of +2 for Ni ion in a SrTi0.95Ni0.05O3 sample. XPS results indicated the promotion of oxygen vacancies. VSM results revealed a paramagnetic behavior at room temperature of all as-prepared samples. Ni-doped samples exhibited ferromagnetic behavior after annealing in argon with the Curie temperature (TC) above 380 K for a sample with x=0.05 as shown by field cooling (FC) and zero-field cooling (ZFC) measurements. The room temperature ferromagnetism (RT-FM) of ferromagnetic samples was suggested to be originated from Ni metal and F-center exchange (FCE) mechanism due to the promotion of oxygen vacancies in the perovskite structure.

  18. Rapid synthesis of Ti-MCM-41 by microwave-assisted hydrothermal method towards photocatalytic degradation of oxytetracycline.

    PubMed

    Chen, Hanlin; Peng, Yen-Ping; Chen, Ku-Fan; Lai, Chia-Hsiang; Lin, Yung-Chang

    2016-06-01

    This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41, which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) were employed. The XRD findings showed that Ti-MCM-41 exhibited a peak at 2θ of 2.2°, which was attributed to the hexagonal MCM-41 structure. The BET (Brunauer-Emmett-Teller) results agreed with the TEM findings that Ti-MCM-41 has a pore size of about 3-5nm and a high surface area of 883m(2)/g. FTIR results illustrated the existence of Si-O-Si and Si-O-Ti bonds in Ti-MCM-41. The appearance of Ti 2p peaks in the XPS results confirmed the FTIR findings that the Ti was successfully doped into the MCM-41 structure. Zeta (ζ)-potential results indicated that the iso-electric point (IEP) of Ti-MCM-41 was at about pH3.02. In this study, the photocatalytic degradation of oxytetracycline (OTC) at different pH was investigated under Hg lamp irradiation (wavelength 365nm). The rate constant (K'obs) for OTC degradation was 0.012min(-1) at pH3. Furthermore, TOC (total organic carbon) and high resolution LC-MS (liquid chromatography-mass spectrometry) analyses were conducted to elucidate the possible intermediate products and degradation pathway for OTC. The TOC removal efficiency of OTC degradation was 87.0%, 74.4% and 50.9% at pH3, 7 and 10, respectively. LC-MS analysis results showed that the degradation products from OTC resulted from the removal of functional groups from the OTC ring.

  19. Adsorption of Cu2+ ions using chitosan-modified magnetic Mn ferrite nanoparticles synthesized by microwave-assisted hydrothermal method

    NASA Astrophysics Data System (ADS)

    Meng, Yuying; Chen, Deyang; Sun, Yitao; Jiao, Dongling; Zeng, Dechang; Liu, Zhongwu

    2015-01-01

    Chitosan-modified Mn ferrite nanoparticles were synthesized by a one-step microwave-assisted hydrothermal method. These Mn ferrite magnetic composite nanoparticles were employed to absorb Cu2+ ions in water. XRD verified the spinel structure of the MnFe2O4 nanoparticles. Chitosan modification does not result in any phase change of MnFe2O4. FTIR and zeta potentials curves for all samples suggest that chitosan can be successfully coated on the Mn ferrites. TEM characterization showed that the modified MnFe2O4 nanoparticles have a cubic shape with a mean diameter of ∼100 nm. For adsorption behavior, the effects of experiment parameters such as solution pH value, contact time and initial Cu2+ ions concentration on the adsorption efficiency were systematically investigated. The results showed that increasing solution pH value and extending contact time are favorable for improving adsorption efficiency. Especially, adsorption efficiency can reach up to 100% and 96.7% after 500 min adsorption at pH 6.5 for the solutions with initial Cu2+ ions concentration of 50 mg/L and 100 mg/L. Adsorption data fits well with the Langmuir isotherm models with a maximum adsorption capacity (qm) and a Langmuir adsorption equilibrium constant (K) of 65.1 mg/g and 0.090 L/mg, respectively. The adsorption kinetic agrees well with pseudo second order model with the pseudo second rate constants (K2) of 0.0468 and 0.00189 g/mg/min for solutions with initial Cu2+ ions of 50 and 100 mg/L, respectively.

  20. Dye-adsorption capacity of high surface-area hydrogen titanate nanosheets processed via modified hydrothermal method.

    PubMed

    Padinhattayil, Hareesh; Augustine, Rimesh; Shukla, Satyajit

    2013-04-01

    High surface-area (380 m2 x g(-1)) hydrogen titanate nanosheets (HTNS) processed via the modified hydrothermal method have been utilized for the removal of methylene blue (MB) dye from an aqueous solution via the surface-adsorption process involving the electrostatic attraction mechanism. The HTNS have been characterized using the transmission electron microscope (TEM), selected-area electron diffraction (SAED), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) specific surface-area measurement techniques. The amount of MB dye adsorbed on the surface of HTNS at equilibrium (q(e)) has been examined as a function of contact time, initial dye-concentration, and initial solution-pH. Within the investigated range of initial solution-pH (2.5-11), the MB dye adsorption on the surface of HTNS has been observed to follow the pseudo-second-order kinetics with the dye-adsorption capacity of 119 mg x g(-1) at the initial solution-pH of - 10. The adsorption equilibrium follows the Langmuir isotherm within the initial solution-pH range of 2.5-10. However, in a highly basic solution (initial solution-pH -11), the adsorption equilibrium has been observed to follow the Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich (DKR) models in the different ranges of initial MB dye concentration. The mere dependence on the DKR model has not been observed within the investigated range of initial solution-pH. The differences in the dye-adsorption characteristics and capacity of HTNS, compared with those of hydrogen titanate nanotubes, have been attributed to the difference in their specific surface-area. Irrespective of the morphology, the maximum coverage of MB dye on the surface of hydrogen titanate has been noted to be the same (52%).

  1. A hydrothermal peroxo method for preparation of highly crystalline silica-titania photocatalysts.

    PubMed

    Krivtsov, Igor; Ilkaeva, Marina; Avdin, Viacheslav; Khainakov, Sergei; Garcìa, Jose R; Ordòñez, Salvador; Dìaz, Eva; Faba, Laura

    2015-04-15

    A new completely inorganic method of preparation of silica-titania photocatalyst has been described. It has been established that the addition of silica promotes crystallinity of TiO2 anatase phase. Relative crystallinity and TiO2 crystal size in the silica-titania particles increase with the silica content until SiO2/TiO2 molar ratio of 0.9, but at higher molar ratios they start to decrease. The single-source precursor containing peroxo titanic (PTA) and silicic acids has been proved to be responsible for high crystallinity of TiO2 encapsulated into amorphous silica. It has been proposed that peroxo groups enhance rapid formation of crystalline titania seeds, while silica controls their growth. It has been concluded from the TEM that the most morphologically uniform anatase crystallites covered with SiO2 particles are prepared at SiO2/TiO2 molar ratio of 0.4. This sample, according to (29)Si NMR, also shows the high content of hydroxylated silica Q(3) and Q(2) groups, and it is the most photocatalytically active in UV-assisted decomposition of methylene blue among the tested materials. It has been determined that the increase in the amount of the condensed Q(4) silica in the mixed oxides leads to the decrease in photocatalytic performance of the material, despite its better crystallinity. High crystallinity, low degree of incorporation of Ti atoms in SiO2 in the mixed oxide and adsorption of methylene blue in the vicinity of photoactive sites on the hydroxylated silica have been considered as the main factors determining the high degradation degree of methylene blue in the presence of silica-titania. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Comparison of structural and electrical properties of Co{sup 2+}doped Mn-Zn soft nano ferrites prepared via coprecipitation and hydrothermal methods

    SciTech Connect

    Anwar, Humaira; Maqsood, Asghari

    2014-01-01

    Graphical abstract: - Highlights: • Coprecipitation and hydrothermal synthesis of Co{sup 2+} doped Mn-Zn ferrites. • Dielectric measurements at 3 MHz and 1 GHz frequencies. • Enhanced DC electrical resistivity for samples prepared from hydrothermal technique. • Impedance studies for the prepared samples showing major contribution due to grains. - Abstract: A series of Co doped Mn-Zn ferrites compounds with the formula Mn{sub 0.5}Zn{sub 0.5−x}Co{sub x}Fe{sub 2}O{sub 4} (x = 0, 0.15, 0.25, 0.35 and 0.50) were successfully synthesized by polyethylene glycol-assisted coprecipitation and hydrothermal methods. The structural characterization of the samples was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). All the samples found to have cubic spinel structure. The average crystallite size of all nanoparticles were estimated using Scherrer's formula and found to lie between 10 and 25 ± 3 nm with small size distribution of particles prepared by hydrothermal method. The FTIR spectrum showed two absorption bands of tetrahedral and octahedral metal-oxygen sites. DC electrical resistivity varied from 4.12 × 10{sup 7} to 8.32 × 10{sup 10} ohm cm with cobalt doping. The dielectric measurements were performed from 20 Hz to 3 MHz and from 1 MHz to 1 GHz frequency ranges. The value of dielectric constant (ε′) varies from 15.54 to 106.25 (1 MHz) and 6.73–16.48 (1 GHz) for all the samples at room temperature. Impedance spectroscopy was carried out from 20 Hz to 3 MHz, at room temperature to study the grains and grain boundaries effect.

  3. A novel hydrothermal method for zinc extraction and separation from zinc ferrite and electric arc furnace dust

    NASA Astrophysics Data System (ADS)

    Wang, Hui-gang; Li, Yang; Gao, Jian-ming; Zhang, Mei; Guo, Min

    2016-02-01

    A novel hydrothermal process was developed to extract zinc from pure zinc ferrite (ZnFe2O4) nanopowder and zinc-containing electric arc furnace (EAF) dust using hexahydrated ferric chloride (FeCl3·6H2O) as a decomposing agent. The effects of solid FeCl3·6H2O to ZnFe2O4 ratio by mass ( R F/Z), hydrothermal reaction temperature, and time on zinc extraction were systematically investigated. In the results, when the hydrothermal reaction is conducted at 150°C for 2 h with R F/Z of 15:20, the efficiency of zinc extraction from ZnFe2O4 reaches 97.2%, and the concentration of ferric ions (Fe3+) in the leaching solution is nearly zero, indicating a high selectivity for zinc. In addition, the zinc extraction efficiency from the EAF dust reaches 94.5% in the case of the hydrothermal reaction performed at 200°C for 10 h with the solid FeCl3·6H2O to EAF dust ratio by mass ( R F/EAF dust) of 15:10. Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.

  4. Hydrothermal synthesis of hydroxyapatite nanorods using pyridoxal-5′-phosphate as a phosphorus source

    SciTech Connect

    Zhao, Xin-Yu; Zhu, Ying-Jie Lu, Bing-Qiang; Chen, Feng; Qi, Chao; Zhao, Jing; Wu, Jin

    2014-07-01

    Graphical abstract: Hydroxyapatite nanorods are synthesized using biocompatible biomolecule pyridoxal-5′-phosphate as a new organic phosphorus source by the hydrothermal method. - Highlights: • Hydrothermal synthesis of hydroxyapatite nanorods is reported. • Biocompatible pyridoxal-5′-phosphate is used as an organic phosphorus source. • This method is simple, surfactant-free and environmentally friendly. - Abstract: Hydroxyapatite nanorods are synthesized by the hydrothermal method using biocompatible biomolecule pyridoxal-5′-phosphate (PLP) as a new organic phosphorus source. In this method, PLP biomolecules are hydrolyzed to produce phosphate ions under hydrothermal conditions, and these phosphate ions react with pre-existing calcium ions to form hydroxyapatite nanorods. The effects of experimental conditions including hydrothermal temperature and time on the morphology and crystal phase of the products are investigated. This method is simple, surfactant-free and environmentally friendly. The products are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis.

  5. A Simple Method for Nucleon-Nucleon Cross Sections in a Nucleus

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1999-01-01

    A simple reliable formalism is presented for obtaining nucleon-nucleon cross sections within a nucleus in nuclear collisions for a given projectile and target nucleus combination at a given energy for use in transport, Monte Carlo, and other calculations. The method relies on extraction of these values from experiments and has been tested and found to give excellent results.

  6. Global Study of the Simple Pendulum by the Homotopy Analysis Method

    ERIC Educational Resources Information Center

    Bel, A.; Reartes, W.; Torresi, A.

    2012-01-01

    Techniques are developed to find all periodic solutions in the simple pendulum by means of the homotopy analysis method (HAM). This involves the solution of the equations of motion in two different coordinate representations. Expressions are obtained for the cycles and periods of oscillations with a high degree of accuracy in the whole range of…

  7. Two Magnets and a Ball Bearing: A Simple Demonstration of the Methods of Images.

    ERIC Educational Resources Information Center

    Poon, W. C. K.

    2003-01-01

    Investigates the behavior of a bar magnet with a steel ball bearing on one pole as it approaches another bar magnet. Maps the problem onto electrostatics and explains observations based on the behavior of point charges near an isolated, uncharged sphere. Offers a simple demonstration of the method of images in electrostatics. (Author/NB)

  8. A SIMPLE HPLC METHOD FOR DETECTING CARBARYL AND 1-NAPHTHOL IN BIOLOGICAL TISSUES.

    EPA Science Inventory

    Carbamates are a class of pesticide used in both agricultural and residential applications. A simple HPLC method for detecting Carb and its metabolite 1-naphthol (Naph) in tissues was developed to try to correlate tissue levels of carbaryl (Carb) (a prototypical carbamate) with c...

  9. 16 CFR 680.25 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... consumer about your products or services, unless the consumer is provided a reasonable and simple method to... a form that can be electronically mailed or processed at an Internet Web site, if the consumer..., such as through posting at an Internet Web site, to opt out solely by paper mail or by visiting a...

  10. 16 CFR 680.25 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... consumer about your products or services, unless the consumer is provided a reasonable and simple method to... a form that can be electronically mailed or processed at an Internet Web site, if the consumer..., such as through posting at an Internet Web site, to opt out solely by paper mail or by visiting a...

  11. Simple Method for Assaying Colistin Methanesulfonate in Plasma and Urine Using High-Performance Liquid Chromatography

    PubMed Central

    Li, Jian; Milne, Robert W.; Nation, Roger L.; Turnidge, John D.; Coulthard, Kingsley; Valentine, Jason

    2002-01-01

    A simple and sensitive high-performance liquid chromatographic method is described for the determination of colistimethate sodium in plasma and urine. The accuracy and reproducibility was within 10.1 and 11.2% with rat plasma and urine, respectively. Several commonly coadministered antibacterial agents do not interfere with the assay. PMID:12234867

  12. Two Magnets and a Ball Bearing: A Simple Demonstration of the Methods of Images.

    ERIC Educational Resources Information Center

    Poon, W. C. K.

    2003-01-01

    Investigates the behavior of a bar magnet with a steel ball bearing on one pole as it approaches another bar magnet. Maps the problem onto electrostatics and explains observations based on the behavior of point charges near an isolated, uncharged sphere. Offers a simple demonstration of the method of images in electrostatics. (Author/NB)

  13. 17 CFR 162.7 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Reasonable and simple methods of opting out. 162.7 Section 162.7 Commodity and Securities Exchanges COMMODITY FUTURES TRADING... electronically mailed or processed through an Internet Web site; (4) Providing a toll-free telephone number;...

  14. 17 CFR 248.125 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Reasonable and simple methods of opting out. 248.125 Section 248.125 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... electronically mailed or processed at an Internet Web site, if the consumer agrees to the electronic delivery...

  15. 17 CFR 248.125 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Reasonable and simple methods of opting out. 248.125 Section 248.125 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) REGULATIONS S-P AND S-AM Regulation S-AM: Limitations on Affiliate Marketing §...

  16. 17 CFR 248.125 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Reasonable and simple methods of opting out. 248.125 Section 248.125 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) REGULATIONS S-P, S-AM, AND S-ID Regulation S-AM: Limitations on Affiliate...

  17. 17 CFR 248.125 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Reasonable and simple methods of opting out. 248.125 Section 248.125 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) REGULATIONS S-P AND S-AM Regulation S-AM: Limitations on Affiliate Marketing §...

  18. 17 CFR 248.125 - Reasonable and simple methods of opting out.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Reasonable and simple methods of opting out. 248.125 Section 248.125 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) REGULATIONS S-P AND S-AM Regulation S-AM: Limitations on Affiliate Marketing §...

  19. Testing a simple field method for assessing nitrate removal in riparian zones

    Treesearch

    Philippe Vidon; Michael G. Dosskey

    2008-01-01

    Being able to identify riparian sites that function better for nitrate removal from groundwater is critical to using efficiently the riparian zones for water quality management. For this purpose, managers need a method that is quick, inexpensive, and accurate enough to enable effective management decisions. This study assesses the precision and accuracy of a simple...

  20. Simple method for determination of patulin production by Penicillium griseofulvum Dierckx.

    PubMed Central

    Torres, M; Sanchis, V; Riba, M; Canela, R

    1986-01-01

    Patulin production by Penicillium griseofulvum was monitored with Sep-Pak cartridges and high-pressure liquid chromatography. Determination and quantification of this metabolite proved to be very simple, and our method saved time and a large amount of organic solvents. PMID:3513700

  1. Simple in-line method to measure the dispersion of an optical system

    NASA Technical Reports Server (NTRS)

    Yao, X. S.; Feinberg, Jack

    1993-01-01

    We describe a simple in-line method to measure the dispersion of an optical system. The light beam passing through the optical system interferes with a reference beam in a spectrometer, and the resulting spectrum yields the quadratic and cubic dispersion terms of the system. We demonstrate this technique on an optical system made of grating pairs.

  2. A Simple Method Enabling Students to Model Impact Cratering from 0° to 90°.

    NASA Astrophysics Data System (ADS)

    Burgener, J. A.

    2016-08-01

    A simple, inexpensive method to produce craters with impact angles ranging from 0° to 90° is presented. It utilizes low speed pellet guns and soft clay. Varying the hardness of the clay and speed of the pellets allows a wide range of experiments.

  3. A SIMPLE HPLC METHOD FOR DETECTING CARBARYL AND 1-NAPHTHOL IN BIOLOGICAL TISSUES.

    EPA Science Inventory

    Carbamates are a class of pesticide used in both agricultural and residential applications. A simple HPLC method for detecting Carb and its metabolite 1-naphthol (Naph) in tissues was developed to try to correlate tissue levels of carbaryl (Carb) (a prototypical carbamate) with c...

  4. A simple enzymic method for the synthesis of [32P]phosphoenolpyruvate.

    PubMed

    Parra, F

    1982-09-01

    A rapid and simple enzymic method is described for the synthesis of [(32)P]phosphoenolpyruvate from [(32)P]P(i), with a reproducible yield of 74%. The final product was shown to be a good substrate for pyruvate kinase (EC 2.7.1.40).

  5. A simple enzymic method for the synthesis of [32P]phosphoenolpyruvate

    PubMed Central

    Parra, Francisco

    1982-01-01

    A rapid and simple enzymic method is described for the synthesis of [32P]phosphoenolpyruvate from [32P]Pi, with a reproducible yield of 74%. The final product was shown to be a good substrate for pyruvate kinase (EC 2.7.1.40). ImagesFig. 1. PMID:7150238

  6. Global Study of the Simple Pendulum by the Homotopy Analysis Method

    ERIC Educational Resources Information Center

    Bel, A.; Reartes, W.; Torresi, A.

    2012-01-01

    Techniques are developed to find all periodic solutions in the simple pendulum by means of the homotopy analysis method (HAM). This involves the solution of the equations of motion in two different coordinate representations. Expressions are obtained for the cycles and periods of oscillations with a high degree of accuracy in the whole range of…

  7. A simple laboratory method for determining flash fire propensity of materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    A simple laboratory method for determining flash fire propensity of materials is described. The apparatus consists of a tube furnace and a combustion tube. The ignition source can be a wooded match but the hot pyrolysis tube itself may be the most suitable ignition source. Test results are presented for various materials including polyethylene, polystyrene, polycarbonate, and polyurethane and polychloroprene flexible foams.

  8. Simple and reliable method for determination of oxygen content in high- Tc copper oxides

    NASA Astrophysics Data System (ADS)

    Maeno, Yoshiteru; Teraoka, Hideki; Matsukuma, Kuniko; Yoshida, Koji; Sugiyama, Kimihiko; Nakamura, Fumihiko; Fujita, Toshizo

    1991-12-01

    We present the details of a simple and reliable iodine-titration method suited for high- Tc copper oxides, in which the use of a solution of ammonium acetate and acetic acid as a buffer agent substantially improves the operation. The results applied to La 2- xM xCuO 4- δ (M = Ba, Sr and Ca) are presented.

  9. A Simple Method for Assessing Upper Limb Force-Velocity Profile in Bench Press.

    PubMed

    Rahmani, Abderrahmane; Samozino, Pierre; Morin, Jean-Benoit; Morel, Baptiste

    2017-06-12

    1) to analyze the reliability and validity of a field computation method based on easy-to-measure data to assess the mean force (F̄) and velocity (v̄) produced during a ballistic bench press movement; and 2) to verify that the force-velocity profile (F-v) obtained with multiple loaded trials is accurately described. Twelve participants performed ballistic bench press against various lifted mass from 30 to 70% of their body mass. For each trial, F̄ and v̄ were determined from an accelerometer (sampling rate: 500Hz; reference method) and a simple computation method based on upper limb mass, barbell flight height and push-off distance. These F̄ and v̄ data were used to establish the F-v relationship for each individual and method. A strong to almost perfect reliability was observed between the two trials (ICC>0.90 for F̄ and 0.80 for v̄, CV%<10%) whatever the considered method. The mechanical variables (F̄, v̄) measured with the two methods, and all the variables extrapolated from the F-v relationships were strongly correlated (r(2) > 0.80, p < 0.001). The practical differences between the two methods for the extrapolated mechanical parameters were all <5% indicating "very probably no differences". The present findings suggest that the simple computation method used here providing valid and reliable information on force and velocity produced during ballistic bench press, in line with those observed in laboratory conditions. This simple method is then a practical tool, which necessitates only three simple parameters (upper limb mass, barbell flight height and push-off distance).

  10. Seismic exploration methods for hydrothermal dolomite reservoirs: A case study of the Trenton-Black River groups

    NASA Astrophysics Data System (ADS)

    Ogiesoba, Osareni Christopher

    This thesis discusses 3D seismic exploration for hydrothermal dolomite (HTD) reservoirs. During this project, I utilized some of the existing algorithms as well as developed my own methods. I mentioned that HTD reservoirs constitute an important hydrocarbon play-type the world over, and are particularly important within the Ordovician aged Trenton-Black River Group in eastern North America. I noted that 3D seismic is the best tool to explore for HTD but it is adversely affected by random noise and acquisition footprint which must be attenuated. I designed a post-stack processing flow that can be applied to attenuate noise, highlight fault terminations, and increase reflection events continuity. By predicting porosity using seismic attributes, I examined the relationships between porosity distribution and faulting, and between porosity and seismic attributes. Results show that porosity development depends on basement-related faults, and that hydrocarbon production rate depends on the presence of faults, fractures and porosity. The results show that the sag observed to be associated with HTD reservoirs on seismic sections is due to velocity pull-down and that the best porosity is developed in these areas. The methods and results presented in this project can be used in other places with similar geologic settings. By way of semblance, I developed a dual-parameter scanning algorithm that can recover both NMO velocity (vnmo) and the effective anisotropic parameter (etaeff) at the same time, from which interval eta (etaint) is obtained by inversion. Noise-free synthetic data application show 10% maximum deviation between the extracted and actual flint values, while noise-contaminated synthetic data show >20% deviation. Real data application shows that it is possible to discriminate between HTD and limestone. Further testing is required to establish its validity. A velocity ratio (Vp/Vs) extracting algorithm was developed using AVO prestack amplitude inversion. Noise

  11. Preparation of nitrogen-doped graphene sheets by a combined chemical and hydrothermal reduction of graphene oxide.

    PubMed

    Long, Donghui; Li, Wei; Ling, Licheng; Miyawaki, Jin; Mochida, Isao; Yoon, Seong-Ho

    2010-10-19

    Nitrogen-doped graphene sheets were prepared through a hydrothermal reduction of colloidal dispersions of graphite oxide in the presence of hydrazine and ammonia at pH of 10. The effect of hydrothermal temperature on the structure, morphology, and surface chemistry of as-prepared graphene sheets were investigated though XRD, N(2) adsorption, solid-state (13)C NMR, SEM, TEM, and XPS characterizations. Oxygen reduction and nitrogen doping were achieved simultaneously under the hydrothermal reaction. Up to 5% nitrogen-doped graphene sheets with slightly wrinkled and folded feature were obtained at the relative low hydrothermal temperature. With the increase of hydrothermal temperature, the nitrogen content decreased slightly and more pyridinic N incorporated into the graphene network. Meanwhile, a jellyfish-like graphene structure was formed by self-organization of graphene sheets at the hydrothermal temperature of 160 °C. Further increase of the temperature to 200 °C, graphene sheets could self-aggregate into agglomerate particles but still contained doping level of 4 wt % N. The unique hydrothermal environment should play an important role in the nitrogen doping and the jellyfish-like graphene formation. This simple hydrothermal method could provide the synthesis of nitrogen-doped graphene sheets in large scale for various practical applications.

  12. A simple method for one-loop renormalization in curved space-time

    SciTech Connect

    Markkanen, Tommi; Tranberg, Anders E-mail: anders.tranberg@uis.no

    2013-08-01

    We present a simple method for deriving the renormalization counterterms from the components of the energy-momentum tensor in curved space-time. This method allows control over the finite parts of the counterterms and provides explicit expressions for each term separately. As an example, the method is used for the self-interacting scalar field in a Friedmann-Robertson-Walker metric in the adiabatic approximation, where we calculate the renormalized equation of motion for the field and the renormalized components of the energy-momentum tensor to fourth adiabatic order while including interactions to one-loop order. Within this formalism the trace anomaly, including contributions from interactions, is shown to have a simple derivation. We compare our results to those obtained by two standard methods, finding agreement with the Schwinger-DeWitt expansion but disagreement with adiabatic subtractions for interacting theories.

  13. A simple and precise method for quantitative analysis of lumefantrine by planar chromatography

    PubMed Central

    Hamrapurkar, Purnima; Phale, Mitesh; Pawar, Sandeep; Patil, Priti; Gandhi, Mittal

    2010-01-01

    A simple, precise and sensitive high performance thin layer chromatographic (HPTLC) method has been developed and validated for drug of choice Lumefantrine in treatment of malaria (P. falciparum). Silica gel 60 F254 HPTLC precoated plates were used for quantitative analytical purpose. Methanol water 9.5 + 0.5 (v/v) was used as the solvent system. Densitometric scanning was carried out with deuterium lamp set at detection wavelength of 266 nm. The response to lumefantrine concentration was linear in the concentration range of 1.25-12.50 μg/ml. The suitability of the method developed and validated was in accordance with the requirements of the ICH guidelines (Q2B). Thus the validated method can be further applied to quantitative analysis of lumefantrine in commercial pharmaceutical dosage form. The proposed method is simple, sensitive, precise and accurate, confirming its pharmaceutical application in routine quality control analysis. PMID:23781415

  14. Microstructure and magnetic properties of MFe{sub 2}O{sub 4} (M = Co, Ni, and Mn) ferrite nanocrystals prepared using colloid mill and hydrothermal method

    SciTech Connect

    Wang, Wei Ding, Zui; Zhao, Xiruo; Wu, Sizhu; Li, Feng; Yue, Ming; Liu, J. Ping

    2015-05-07

    Three kinds of spinel ferrite nanocrystals, MFe{sub 2}O{sub 4} (M = Co, Ni, and Mn), are synthesized using colloid mill and hydrothermal method. During the synthesis process, a rapid mixing and reduction of cations with sodium borohydride (NaBH{sub 4}) take place in a colloid mill then through a hydrothermal reaction, a slow oxidation and structural transformation of the spinel ferrite nanocrystals occur. The phase purity and crystal lattice parameters are estimated by X-ray diffraction studies. Scanning electron microscopy and transmission electron microscopy images show the morphology and particle size of the as-synthesized ferrite nanocrystals. Raman spectrum reveals active phonon modes at room temperature, and a shifting of the modes implies cation redistribution in the tetrahedral and octahedral sites. Magnetic measurements show that all the obtained samples exhibit higher saturation magnetization (M{sub s}). Meanwhile, experiments demonstrate that the hydrothermal reaction time has significant effects on microstructure, morphologies, and magnetic properties of the as-synthesized ferrite nanocrystals.

  15. Spectral and structural characteristics of Lu1 - x - y Ce x Tb y BO3 orthoborates prepared by the hydrothermal synthesis method

    NASA Astrophysics Data System (ADS)

    Shmurak, S. Z.; Kedrov, V. V.; Kiselev, A. P.; Fursova, T. N.; Rybchenko, O. G.

    2017-06-01

    The structure, IR absorption spectra, morphology, and photoluminescence spectral characteristics of Lu1- x- y Ce x Tb y BO3 solid solutions prepared by the hydrothermal synthesis method have been investigated. According to the X-ray powder diffraction data, the Lu1- x- y Ce x Tb y BO3 samples hydrothermally synthesized at a temperature T = 200°C have the vaterite structure, and all the observed diffraction peaks correspond to the hexagonal phase with the space group P63/ mmc, which is isostructural to pure lutetium borate LuBO3. Annealing of these samples at T = 970°C leads to a change in the structural modification and to the transition of the samples to the monoclinic phase with the space group C2/ c. It has been found that, after annealing of these samples at temperatures T = 800-970°C, the luminescence intensity of Tb3+ ions upon excitation in the absorption band of Ce3+ ions increases by more than two orders of magnitude and becomes much higher than that in compounds of the same composition, but prepared by high-temperature synthesis. At the same time, annealing of lutetium borate doped only with terbium does not lead to a significant change in the luminescence intensity of Tb3+ ions. The possible reasons for a multiple increase in the luminescence intensity of terbium ions due to the annealing of the hydrothermally synthesized lutetium orthoborate samples doped with cerium and terbium ions have been discussed.

  16. Simple method for adaptive filtering of motion artifacts in E-textile wearable ECG sensors.

    PubMed

    Alkhidir, Tamador; Sluzek, Andrzej; Yapici, Murat Kaya

    2015-08-01

    In this paper, we have developed a simple method for adaptive out-filtering of the motion artifact from the electrocardiogram (ECG) obtained by using conductive textile electrodes. The textile electrodes were placed on the left and the right wrist to measure ECG through lead-1 configuration. The motion artifact was induced by simple hand movements. The reference signal for adaptive filtering was obtained by placing additional electrodes at one hand to capture the motion of the hand. The adaptive filtering was compared to independent component analysis (ICA) algorithm. The signal-to-noise ratio (SNR) for the adaptive filtering approach was higher than independent component analysis in most cases.

  17. A simple method of aortic valve reconstruction with fixed pericardium in children

    PubMed Central

    Hosseinpour, Amir-Reza; González-Calle, Antonio; Adsuar-Gómez, Alejandro; Santos-deSoto, José

    2013-01-01

    Aortic valve reconstruction with fixed pericardium may occasionally be very useful when treating children with aortic valve disease. This is because diseased aortic valves in children are sometimes too dysmorphic for simple repair without the addition of material, their annulus may be too small for a prosthesis, and the Ross operation may be precluded due to other congenital anomalies such as pulmonary valvar or coronary malformations. Such reconstruction is usually technically demanding and requires much precision. We describe a simple alternative method, which we have carried out in 3 patients, aged 1 week, 3 years and 12 years, respectively, with good early results. PMID:23343835

  18. A simple method for converting frequency domain aerodynamics to the time domain

    NASA Technical Reports Server (NTRS)

    Dowell, E. H.

    1980-01-01

    A simple, direct procedure was developed for converting frequency domain aerodynamics into indicial aerodynamics. The data required for aerodynamic forces in the frequency domain may be obtained from any available (linear) theory. The method retains flexibility for the analyst and is based upon the particular character of the frequency domain results. An evaluation of the method was made for incompressible, subsonic, and transonic two dimensional flows.

  19. Contrast of doppler radar wind field retrieval methods between VVP and advanced simple adjoint model

    NASA Astrophysics Data System (ADS)

    Kang, Hao; Wei, Ming; Tang, Liping

    2007-12-01

    The wind retrieval of single Doppler radar data is important for severe weather forecasting. The contrast of wind retrieve methods between VVP and advanced simple adjoint model has been made. The typhoon and rainstorm wind retrieval results indicate two methods have their own advantage and disadvantage because the assume conditions and processing ways are different, this work is valuable for the retrieval wind field application in research and operation.

  20. Simple SPION Incubation as an Efficient Intracellular Labeling Method for Tracking Neural Progenitor Cells Using MRI

    PubMed Central

    D. M., Jayaseema; Lai, Jiann-Shiun; Hueng, Dueng-Yuan; Chang, Chen

    2013-01-01

    Cellular magnetic resonance imaging (MRI) has been well-established for tracking neural progenitor cells (NPC). Superparamagnetic iron oxide nanoparticles (SPIONs) approved for clinical application are the most common agents used for labeling. Conventionally, transfection agents (TAs) were added with SPIONs to facilitate cell labeling because SPIONs in the native unmodified form were deemed inefficient for intracellular labeling. However, compelling evidence also shows that simple SPION incubation is not invariably ineffective. The labeling efficiency can be improved by prolonged incubation and elevated iron doses. The goal of the present study was to establish simple SPION incubation as an efficient intracellular labeling method. To this end, NPCs derived from the neonatal subventricular zone were incubated with SPIONs (Feridex®) and then evaluated in vitro with regard to the labeling efficiency and biological functions. The results showed that, following 48 hours of incubation at 75 µg/ml, nearly all NPCs exhibited visible SPION intake. Evidence from light microscopy, electron microscopy, chemical analysis, and magnetic resonance imaging confirmed the effectiveness of the labeling. Additionally, biological assays showed that the labeled NPCs exhibited unaffected viability, oxidative stress, apoptosis and differentiation. In the demonstrated in vivo cellular MRI experiment, the hypointensities representing the SPION labeled NPCs remained observable throughout the entire tracking period. The findings indicate that simple SPION incubation without the addition of TAs is an efficient intracellular magnetic labeling method. This simple approach may be considered as an alternative approach to the mainstream labeling method that involves the use of TAs. PMID:23468856

  1. Simple SPION incubation as an efficient intracellular labeling method for tracking neural progenitor cells using MRI.

    PubMed

    Chen, Chiao-Chi V; Ku, Min-Chi; D M, Jayaseema; Lai, Jiann-Shiun; Hueng, Dueng-Yuan; Chang, Chen

    2013-01-01

    Cellular magnetic resonance imaging (MRI) has been well-established for tracking neural progenitor cells (NPC). Superparamagnetic iron oxide nanoparticles (SPIONs) approved for clinical application are the most common agents used for labeling. Conventionally, transfection agents (TAs) were added with SPIONs to facilitate cell labeling because SPIONs in the native unmodified form were deemed inefficient for intracellular labeling. However, compelling evidence also shows that simple SPION incubation is not invariably ineffective. The labeling efficiency can be improved by prolonged incubation and elevated iron doses. The goal of the present study was to establish simple SPION incubation as an efficient intracellular labeling method. To this end, NPCs derived from the neonatal subventricular zone were incubated with SPIONs (Feridex®) and then evaluated in vitro with regard to the labeling efficiency and biological functions. The results showed that, following 48 hours of incubation at 75 µg/ml, nearly all NPCs exhibited visible SPION intake. Evidence from light microscopy, electron microscopy, chemical analysis, and magnetic resonance imaging confirmed the effectiveness of the labeling. Additionally, biological assays showed that the labeled NPCs exhibited unaffected viability, oxidative stress, apoptosis and differentiation. In the demonstrated in vivo cellular MRI experiment, the hypointensities representing the SPION labeled NPCs remained observable throughout the entire tracking period. The findings indicate that simple SPION incubation without the addition of TAs is an efficient intracellular magnetic labeling method. This simple approach may be considered as an alternative approach to the mainstream labeling method that involves the use of TAs.

  2. A simple and efficient method for isolating small RNAs from different plant species

    PubMed Central

    2011-01-01

    Background Small RNAs emerged over the last decade as key regulators in diverse biological processes in eukaryotic organisms. To identify and study small RNAs, good and efficient protocols are necessary to isolate them, which sometimes may be challenging due to the composition of specific tissues of certain plant species. Here we describe a simple and efficient method to isolate small RNAs from different plant species. Results We developed a simple and efficient method to isolate small RNAs from different plant species by first comparing different total RNA extraction protocols, followed by streamlining the best one, finally resulting in a small RNA extraction method that has no need of first total RNA extraction and is not based on the commercially available TRIzol® Reagent or columns. This small RNA extraction method not only works well for plant tissues with high polysaccharide content, like cactus, agave, banana, and tomato, but also for plant species like Arabidopsis or tobacco. Furthermore, the obtained small RNA samples were successfully used in northern blot assays. Conclusion Here we provide a simple and efficient method to isolate small RNAs from different plant species, such as cactus, agave, banana, tomato, Arabidopsis, and tobacco, and the small RNAs from this simplified and low cost method is suitable for downstream handling like northern blot assays. PMID:21349188

  3. A Simple and Reliable Method of Design for Standalone Photovoltaic Systems

    NASA Astrophysics Data System (ADS)

    Srinivasarao, Mantri; Sudha, K. Rama; Bhanu, C. V. K.

    2016-08-01

    Standalone photovoltaic (SAPV) systems are seen as a promoting method of electrifying areas of developing world that lack power grid infrastructure. Proliferations of these systems require a design procedure that is simple, reliable and exhibit good performance over its life time. The proposed methodology uses simple empirical formulae and easily available parameters to design SAPV systems, that is, array size with energy storage. After arriving at the different array size (area), performance curves are obtained for optimal design of SAPV system with high amount of reliability in terms of autonomy at a specified value of loss of load probability (LOLP). Based on the array to load ratio (ALR) and levelized energy cost (LEC) through life cycle cost (LCC) analysis, it is shown that the proposed methodology gives better performance, requires simple data and is more reliable when compared with conventional design using monthly average daily load and insolation.

  4. A Simple and Reliable Method of Design for Standalone Photovoltaic Systems

    NASA Astrophysics Data System (ADS)

    Srinivasarao, Mantri; Sudha, K. Rama; Bhanu, C. V. K.

    2017-06-01

    Standalone photovoltaic (SAPV) systems are seen as a promoting method of electrifying areas of developing world that lack power grid infrastructure. Proliferations of these systems require a design procedure that is simple, reliable and exhibit good performance over its life time. The proposed methodology uses simple empirical formulae and easily available parameters to design SAPV systems, that is, array size with energy storage. After arriving at the different array size (area), performance curves are obtained for optimal design of SAPV system with high amount of reliability in terms of autonomy at a specified value of loss of load probability (LOLP). Based on the array to load ratio (ALR) and levelized energy cost (LEC) through life cycle cost (LCC) analysis, it is shown that the proposed methodology gives better performance, requires simple data and is more reliable when compared with conventional design using monthly average daily load and insolation.

  5. On Development of a Problem Based Learning System for Linear Algebra with Simple Input Method

    NASA Astrophysics Data System (ADS)

    Yokota, Hisashi

    2011-08-01

    Learning how to express a matrix using a keyboard inputs requires a lot of time for most of college students. Therefore, for a problem based learning system for linear algebra to be accessible for college students, it is inevitable to develop a simple method for expressing matrices. Studying the two most widely used input methods for expressing matrices, a simpler input method for expressing matrices is obtained. Furthermore, using this input method and educator's knowledge structure as a concept map, a problem based learning system for linear algebra which is capable of assessing students' knowledge structure and skill is developed.

  6. A simple method for evaluating the trapping performance of acoustic tweezers

    NASA Astrophysics Data System (ADS)

    Li, Ying; Lee, Changyang; Ho Lam, Kwok; Kirk Shung, K.

    2013-02-01

    The purpose of this paper is to present a rapid and simple method to evaluate the trapping performance of high frequency focused ultrasonic transducers for acoustic tweezer applications. The method takes into consideration the friction between the particle to be trapped and the surface that it resides on. As a result it should be more reliable and accurate than the methods proposed previously. The trapping force produced by a 70-MHz press-focused transducer was measured to evaluate the performance of this approach. This method demonstrates its potential in optimizing the excitation conditions for acoustic tweezer applications and the design of acoustic tweezers.

  7. A simple method for evaluating the trapping performance of acoustic tweezers.

    PubMed

    Li, Ying; Lee, Changyang; Ho Lam, Kwok; Kirk Shung, K

    2013-02-25

    The purpose of this paper is to present a rapid and simple method to evaluate the trapping performance of high frequency focused ultrasonic transducers for acoustic tweezer applications. The method takes into consideration the friction between the particle to be trapped and the surface that it resides on. As a result it should be more reliable and accurate than the methods proposed previously. The trapping force produced by a 70-MHz press-focused transducer was measured to evaluate the performance of this approach. This method demonstrates its potential in optimizing the excitation conditions for acoustic tweezer applications and the design of acoustic tweezers.

  8. A Simple Method for International Standardization of Photographic Documentation for Aesthetic Plastic Surgery.

    PubMed

    Rhee, Seung Chul

    2017-02-03

    Due to the lack of internationally standardized, objective, and scientific photographic standardization methods, differences in photographic documents have gravely affected the truth of surgical outcomes by visual misperception or illusion, thus hindering the development of plastic surgery clinically and scholastically. Here I suggest a simple method for standardization of facial photographs. The method consists of an imaginary transverse line (tentatively the "PSA line") rather than the Frankfort horizontal plane and uses a white background with black grids and standard RGB with CMYK circles. This simplified method of photographic standardization would help our professional society to make international standards on facial photographic documentation to maintain scholastic ethics, conscience, and morals.

  9. A simple method of catalase purification for the undergraduate experimental course.

    PubMed

    Chen, Qian; Cheng, Meng; Wang, Yinnan; Yao, Ming; Chen, Yongchun; Gao, Yuan; Ding, Wenyuan

    2015-02-01

    Catalase is a characteristic enzyme of peroxisomes, of which it is the most abundant protein. This enzyme serves as a typical example of a peroxisomal enzyme and is important in the teaching of biochemistry and molecular biology. Although there is substantial information regarding catalase purification, purifying catalase for the junior‑grade undergraduate experimental course face challenges in obtaining materials and increasingly expensive purification equipment. This study presents a simple method for the purification of mouse liver catalase using ethanol‑chloroform treatment, sodium sulfate fractionation, dialysis and Sephadex G‑200 gel filtration chromatography. Catalase was purified 31.8‑fold with an 18.3% yield. The advantages of this method were its low operating environment requirements, simple procedure and reduced cost. Furthermore, the method was designed to improve students' comprehensive ability and manipulative ability and to introduce a sense of innovation in the fields of biochemistry and molecular biology during their junior year.

  10. A simple method to determine leakage location in water distribution based on pressure profiles

    NASA Astrophysics Data System (ADS)

    Prihtiadi, Hafizh; Azwar, Azrul; Djamal, Mitra

    2016-03-01

    Nowadays, the pipeline leak is a serious problem for water distributions in big cities and the government that needs action and a great solution. Several techniques have been developed to improve the accuracy, the limitation of losses, and decrease environmental damage. However, these methods need highly costs and complexity equipment. This paper presents a simple method to determine leak location with the gradient intersection method calculations. A simple water distribution system have been built on PVC pipeline along 4m, diameter 15mm and 12 pressure sensors which placed into the pipeline. Each sensor measured the pressure for each point and send the data to microcontroller. The artificial hole was made between the sixth and seventh of sensor. With three holes, the system calculated and analyzed the leak location with error 3.67%.

  11. A simple and efficient solar cell parameter extraction method from a single current-voltage curve

    NASA Astrophysics Data System (ADS)

    Zhang, Chunfu; Zhang, Jincheng; Hao, Yue; Lin, Zhenhua; Zhu, Chunxiang

    2011-09-01

    In this work, a simple and efficient method for the extraction of all the parameters of a solar cell from a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. By reducing the number of the parameters, the expression for I only depends on the ideality factor n, the series resistance Rs, and the shunt resistance Rsh. This analytic expression is directly used to fit the experimental data and extract the device parameters. This simple solar cell parameter extraction method can be directly applied for all kinds of solar cells whose I-V characteristics follow the single-diode model. The parameters of various solar devices including silicon solar cells, silicon solar modules, dye-sensitized solar cells, and organic solar cells with standalone, tandem, and multi-junction structures have been successfully extracted by using our proposed method.

  12. A simple and fast method for extraction and quantification of cryptophyte phycoerythrin.

    PubMed

    Thoisen, Christina; Hansen, Benni Winding; Nielsen, Søren Laurentius

    2017-01-01

    The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equipment. The cryptophyte cells on the filters were disrupted at -80 °C and added phosphate buffer for extraction at 4 °C followed by absorbance measurement. The cryptophyte Rhodomonas salina was used as a model organism. •Simple method for extraction and quantification of phycoerythrin from cryptophytes.•Minimal usage of equipment and chemicals, and low labor costs.•Applicable for industrial and biological purposes.

  13. Synthesis and in-depth analysis of highly ordered yttrium doped hydroxyapatite nanorods prepared by hydrothermal method and its mechanical analysis

    SciTech Connect

    Nathanael, A. Joseph; Mangalaraj, D.; Hong, S.I.; Masuda, Y.

    2011-12-15

    In this study, undoped and yttrium (Y) doped nanocrystalline hydroxyapatite crystals were synthesized by the hydrothermal method at 180 Degree-Sign C for 24 h. Highly ordered and oriented hydroxyapatite (HAp) nanorods were prepared by yttrium doping and their nanostructure and physical properties were compared with those of undoped HAp rods. FESEM images showed that the doping with Y ions reduced the diameter (from 25 nm to 15 nm) and increased the length (from 95 nm to 115 nm) of the synthesized rods. The aspect ratio of the undoped and Y-doped nanorods were calculated to be 4.303 (SD = 0.0959) and 7.61 (SD = 0.0355), respectively. Specific surface area (SSA) analysis showed that SSA also increased from 66.74 m{sup 2}/g to 68.57 m{sup 2}/g with the addition of yttrium. Y-doped HAp nanorod reinforced HMWPE composites displayed the better mechanical performance than those reinforced with pure HAp nanorods. The possible strengthening of nanorods and the increase of SSA due to the reduction in the size of nanorods in the presence of yttrium may have contributed to the strengthening of Y-doped HAp/HMWPE composites. - Graphical Abstract: Highly ordered and oriented yttrium doped hydroxyapatite (HAp) nanorods were prepared by hydrothermal method. For undoped HAp the average length of the nanorod is 95 nm with mean diameter of 24 nm and for a Y doped nanorod the average length is {approx} 115 nm and the mean diameter is 15 nm. Mechanical analysis was carried out by polymer/nanoparticle composite method. Highlights: Black-Right-Pointing-Pointer Yttrium doped hydroxyapatite nanorods were prepared by hydrothermal method. Black-Right-Pointing-Pointer The nanorods have highly uniform size distribution. Black-Right-Pointing-Pointer Yttrium substitution and nanostructure formation was confirmed by careful analysis. Black-Right-Pointing-Pointer Mechanical strength was analyzed by polymer nanoparticle reinforcement method.

  14. Hydrothermal treatment and enzymatic hydrolysis of Tamarix ramosissima: evaluation of the process as a conversion method in a biorefinery concept.

    PubMed

    Xiao, Ling-Ping; Shi, Zheng-Jun; Xu, Feng; Sun, Run-Cang

    2013-05-01

    The present work investigated the effects of hydrothermal treatment (HTT) of Tamarix ramosissima by determination of sugar and inhibitor formation in the liquid fraction, and chemical and morphological changes of the pretreated solid material coupled with an evaluation of enzymatic hydrolysis. HTT was carried out in a batch reactor system at a maximal temperature (TMAX 180-240 °C) and evaluated for severities logRo ranging from 2.40 to 4.17. The liquid fractions were analyzed by HPLC, GPC, and GC-MS. The morphology and composition of the solid residues were characterized using an array of techniques, such as SEM, XRD, BET surface area, and CP/MAS (13)C NMR. Using a variety of tools, we have developed a better understanding of how HTT process affects biomass structure and cellulose properties that impact on its digestibility. These results provided new insights into the factors limiting enzymatic digestibility and mechanism of biomass deconstruction during hydrothermal process.

  15. Bismuth oxide decorated graphene oxide nanocomposites synthesized via sonochemical assisted hydrothermal method for adsorption of cationic organic dyes.

    PubMed

    Das, Trupti R; Patra, Santanu; Madhuri, Rashmi; Sharma, Prashant K

    2017-09-01

    Bismuth oxide decorated graphene oxide (Bi2O3@GO) nanocomposites were successfully synthesized by sonochemical method followed by hydrothermal treatment. The structural, morphology/microstructure and functional groups were investigated through X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared (FTIR) spectroscopy, respectively. In the FESEM and TEM studies, well dispersed Bi2O3 nanoparticles of size 3-5nm were found uniformly distributed throughout the surface and edges of GO sheets. The HRTEM measurements on the Bi2O3 nanoparticle decorated graphene oxide shows imaged lattice spacing of 3.2Å corresponding to (111) plane of Bi2O3 which confirms the successful synthesis of bismuth oxide decorated graphene oxide (Bi2O3@GO) nanocomposite. The synthesized nanocomposite was employed for adsorption and removal of cationic organic dyes like RhB from industrial wastewater. The effect of various parameters, viz., contact time, temperature, pH and amount of adsorbent on the adsorption capability as well as dye removal capacity of the adsorbent was studied in detail. Under optimized conditions, like, contact time (65min), amount of adsorbent (5mg), temperature (35°) and pH (4), the adsorption capacity of GO and Bi2O3@GO were recorded and the percentage of removal was found to be 64% and 80.7% for GO and Bi2O3@GO, respectively. The Bi2O3@GO nanocomposite shows higher adsorption capacity (320mg/g) as compare to only GO (224mg/g). The adsorption isotherm follows both the Temkin as well as Langmuir isotherm having heat of sorption 65.88 with Langmuir constant of 13.13 corresponding to the complete monolayer coverage of 387.44mg/g. The adsorption kinetics also follow, both pseudo first order and intraparticle diffusion model with adsorption capacity of 84.91mg/g and intra particle diffusion rate constant of 10.53mg/g min(1/2) for Bi2O3@GO nanocomposites. Our results suggest that the

  16. In situ synthesis of TiH{sub 2} layer on metallic titanium foil through gaseous hydrogen free acid-hydrothermal method

    SciTech Connect

    Ren, Na; Wang, Guancong; Liu, Hong; Ohachi, Tadashi

    2014-02-01

    Graphical abstract: The reaction mechanism for in situ synthesizing TiH{sub 2} layer on titanium foil by a gaseous hydrogen free acid-hydrothermal methodology. - Highlights: • A dense TiH{sub 2} layer is synthesized by a hydrogen free acid-hydrothermal method. • Hydrogen in a TiH{sub 2} layer synthesized can release at low temperature. • During the dehydrogenation process, there is no any intermediate phase forming. • We report a method of low-cost, low-risk and convenience toward productive TiH{sub 2}. - Abstract: A novel strategy for synthesis of TiH{sub 2} layer on surface of metallic titanium by using an acid-hydrothermal method was proposed. During the synthesis process, no any elemental hydrogen was involved. X-ray powder diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy results confirmed that a TiH{sub 2} layer of 20 μm thickness on a Ti foil surface can be formed in situ by an interface reaction of metallic titanium with sulfuric acid solution, hydrochloric acid, or phosphoric acid, which is a hydrogen self-storage process. By tuning reaction parameters, for example, concentration of acid, composition and morphology of TiH{sub 2}-Ti hybrid materials can be adjusted. The TiH{sub 2} layer on a metallic titanium surface can be decompounded completely heated below 400 °C. This convenient, safe and low-cost method is a promising gaseous hydrogen free approach for the synthesis of hydride-based hydrogen storage materials.

  17. Synthesis of Mg{sub 2}SiO{sub 4}:Dy{sup 3+} nanoparticles by hydrothermal method and investigation of their thermo and photo luminescence properties

    SciTech Connect

    Ghahari, M.; Mostafavi, K.

    2016-05-15

    Highlights: • Mg{sub 2}SiO{sub 4}:Dy{sup 3+} nanoparticles have been prepared by hydrothermal and combustion methods. • Thermo and photo luminescent behavior of Mg{sub 2}SiO{sub 4}:Dy{sup 3+} was studied. • The effect of synthesis method on TL properties of Mg{sub 2}SiO{sub 4}:Dy{sup 3+} was investigated. • The optimal dopant concentration for thermo-luminescent property was obtained. - Abstract: In this study, photo and thermo-luminescent properties of Nano crystalline Mg{sub 2}SiO{sub 4}:Dy{sup 3+} prepared by a hydrothermal method were studied and compared to those of nanoparticles prepared by combustion method. The synthesized sample was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and photoluminescence spectroscopy. The effect of Dy concentration on photo and thermoluminescent intensities was studied. The X-ray diffraction (XRD) patterns of the samples revealed that forsterite was formed as a major phase for all the samples. The crystallite size was found to be in the range of 20–50 nm. The thermo luminescent glow curve indicated that the hydrothermal sample was more efficient than the combustion sample. Two prominent TL bands located at 200 nm and 320 nm were recorded. The prepared nanoparticles exhibited a roughly linear dose response to absorbed dose of 1000 Gy received from 60Co gamma source, suggesting that nanomaterial could be a good candidate for high dose dosimetry.

  18. The estimation of fibrinogen levels in animal plasmas by a simple refractometric method. A comparison with a biuret method.

    PubMed

    Sutton, R H

    1977-05-01

    A comparison was made between a biuret (reference) method and a simple refractometric (test) method for measuring fibrinogen levels in 84 animal plasmas. Although the correlation between the two methods was high (4=0.90 P less than 0-001) there was considerable random variation in the refractometric results in relation to the biuret results. This was thought to be due in part to the fact that refractometric results could only be expressed in multiples of 2.4 g/litre. In spite of this limitation, the refractometric method, on the grounds of speen and simplicity, is considered to have worthwhile application for fibrinogen determinations in practice laboratory.

  19. Characterization, properties and catalytic application of TiO{sub 2} nanotubes prepared by ultrasonic-assisted sol-hydrothermal method

    SciTech Connect

    Chen, Jinyuan; Wang, Huijuan; Wei, Xiuzhen; Zhu, Liping

    2012-11-15

    Graphical abstract: A novel class of titania nanotubes (TNTs) have been prepared by ultrasonic assisted sol-hydrothermal method using tetrabutyl titanate and ethanol as the precursors. The physicochemical characteristics of the catalysts were investigated by transmission electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller method, Differential Scanning Calorimeters-Thermogravimetric Analysis (DSC–TG) and UV–vis absorption spectra. The photocatalytic activity of the products was evaluated in terms of reactive brilliant red X-3B in an aqueous solution under UV irradiation for 1 h. The results showed that the catalyst revealed an excellent photocatalytic activity. The degradation rate of reactive brilliant X-3B could be up to 96%. Display Omitted Highlights: ► TiO{sub 2} nanotubes were prepared by ultrasonic-assisted sol-hydrothermal method. ► TEM, HRTEM, XRD, and BET were used to study morphology and crystalline structure. ► FTIR, DSC-TG was used to investigate pyrolytic process and phase structure. ► UV–vis absorption spectra were used to evaluate the photocatalysis of catalysts. ► Dye degradation result showed that the catalyst had excellent photocatalytic activity. -- Abstract: A novel class of titania nanotubes (TNTs) have been prepared by ultrasonic assisted sol-hydrothermal method using tetrabutyl titanate and ethanol as the precursors. The physicochemical characteristics of the catalysts were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, Differential Scanning Calorimeters-Thermogravimetric Analysis (DSC-TG) and UV–vis absorption spectra. The photocatalytic activity of the products was evaluated in terms of reactive brilliant red X-3B in an aqueous solution under UV irradiation for 1 h. The results showed that the anatase nanotubes prepared by ultrasonic assisted sol-hydrothermal method exhibited excellent photocatalytic activity. The degradation rate of

  20. Simple method for necropsy dissection of the abdominal organs after abdominal surgery.

    PubMed Central

    Culora, G A; Roche, W R

    1996-01-01

    This paper illustrates a simple method of necropsy dissection of the abdominal organs after abdominal surgery. The organs are removed in one block as per the method described by Letulle. A retroperitoneal approach is then used. Structures are dissected away in a series of layers using the vasculature for guidance. This technique permits the examination of important structures in the postoperative abdomen which would otherwise be extremely difficult and time consuming using conventional methods. The anatomy is demonstrated without being obscured by the contents of the peritoneal cavity. Images PMID:9038770

  1. Simple fiber-optic autocollimation method for determining the focal lengths of optical elements.

    PubMed

    Ilev, I K

    1995-03-15

    A novel simple fiber-optic autocollimation method for determining the focal lengths of lenses and objectives is presented. This method is based on the intensity sensing of reflected light, photoelectric measurement, and the use of single-mode optical fiber. This fiber serves simultaneously as a point light source for the formation of a collimated input laser beam and as a receiver that is highly sensitive to spatial displacements for the autocollimation backreflectance. The method permits us to locate the focal point spatially and to determine the back focal length of a focusing optical element with accuracies exceeding 1 and 2 microm, respectively, which are confirmed by both experimental and analytical investigations.

  2. An improved simple colorimetric method for quantitation of non-transferrin-bound iron in serum.

    PubMed

    Zhang, D; Okada, S; Kawabata, T; Yasuda, T

    1995-03-01

    A simple method for direct quantitation of non-transferrin-bound iron (NTBI) in serum is introduced. NTBI was separated from serum by adding excess nitrilotriacetic acid disodium salt (NTA) to serum to form an Fe-NTA complex and then ultrafiltrated using a micro-filter. The NTBI in the ultrafiltrate was quantitated using a bathophenanthroline-based method. The optimal detection condition and several potential confounding factors were investigated. The actual measurements to samples in vivo and in vitro showed that this method is very practical.

  3. A Simple Spectrofluorimetric Method for the Determination of Losartan in Some Tablet Dosage Forms

    NASA Astrophysics Data System (ADS)

    Taher, M. A.; Asadollahzadeh, H.; Fazelirad, H.

    2015-11-01

    A very simple and sensitive spectrofluorimetric method was developed for the direct determination of losartan in some commercial tablets. The suggested method is based on the linear relationship between 0.1-5.0 μg/ml of losartan and its fluorescence intensity at 400 nm in acidic medium. The detection limit and relative standard deviation (for ten repetitive measurements of 2.0 μg/ml) were obtained as 12.0 ng/ml and 1.35%, respectively. The recommended method was successfully applied for the determination of losartan in three types of commercial tablets from different brands.

  4. A simple method for measuring power, force, velocity properties, and mechanical effectiveness in sprint running.

    PubMed

    Samozino, P; Rabita, G; Dorel, S; Slawinski, J; Peyrot, N; Saez de Villarreal, E; Morin, J-B

    2016-06-01

    This study aimed to validate a simple field method for determining force- and power-velocity relationships and mechanical effectiveness of force application during sprint running. The proposed method, based on an inverse dynamic approach applied to the body center of mass, estimates the step-averaged ground reaction forces in runner's sagittal plane of motion during overground sprint acceleration from only anthropometric and spatiotemporal data. Force- and power-velocity relationships, the associated variables, and mechanical effectiveness were determined (a) on nine sprinters using both the proposed method and force plate measurements and (b) on six other sprinters using the proposed method during several consecutive trials to assess the inter-trial reliability. The low bias (<5%) and narrow limits of agreement between both methods for maximal horizontal force (638 ± 84 N), velocity (10.5 ± 0.74 m/s), and power output (1680 ± 280 W); for the slope of the force-velocity relationships; and for the mechanical effectiveness of force application showed high concurrent validity of the proposed method. The low standard errors of measurements between trials (<5%) highlighted the high reliability of the method. These findings support the validity of the proposed simple method, convenient for field use, to determine power, force, velocity properties, and mechanical effectiveness in sprint running.

  5. Development of a new simple estimating method for protein, fat, and carbohydrate in cooked foods.

    PubMed

    Kumae, T

    2000-01-01

    Evaluations of daily nutrient intakes with practical accuracy contribute not only to public but also to personal health. To obtain accurate estimations of nutrient intake, chemical analyses of a duplicate sample of all foods consumed are recommended. But these analytical methods are expensive, time consuming, and not practically applicable for field surveys dealing with numerous food samples. To solve this problem, a new rapid and simple method of estimating nutrients is developed here. Elemental compositions of cooked foods were examined using a high speed and high performance carbon, hydrogen, and nitrogen autoanalyzer, and the results showed good reproducibility. A significant correlation between Kjeldahl's and the autoanalyzer methods was observed in the nitrogen measurement (n=20; r =0.999; p< 0.001), and very good agreement was observed between the methods. Therefore, the nitrogen amount obtained by the autoanalyzer was used for the estimation of the protein proportion in the cooked foods. The fat and carbohydrate proportions estimated by the new method correlated with the values obtained by the chemical method (p< 0.001 each). There were also good agreements of fat and carbohydrate proportions between the chemical and the new estimation methods. According to these results, the new, rapid and simple estimation method established in this study should be applicable to nutritional research.

  6. The Reality-Based Learning Method: A Simple Method for Keeping Teaching Activities Relevant and Effective

    ERIC Educational Resources Information Center

    Smith, Louise W.; Van Doren, Doris C.

    2004-01-01

    Active and experiential learning theory have not dramatically changed collegiate classroom teaching methods, although they have long been included in the pedagogical literature. This article presents an evolved method, reality based learning, that aids professors in including active learning activities with feelings of clarity and confidence. The…

  7. Simple spectrophotometric method for estimation of disodium edetate in topical gel formulations

    PubMed Central

    Kamboj, Sunil; Sharma, Deepak; Nair, Anroop B.; Kamboj, Suman; Sharma, Rakesh Kumar; Ali, Javed; Pramod, K; Ansari, S. H.

    2011-01-01

    A simple, sensitive, cost-effective and reproducible UV-spectrophotometric method has been developed and validated for the estimation of disodium edetate in topical gel formulations. Solution of disodium edetate reacts with ferric chloride to form complex in 0.1 N HCl giving λmax at 270 nm. Beer's law was obeyed in the concentration range of 5–50 μg/mL (r2= 0.9997). The limit of detection and limit of quantitation were found to be 1.190 and 3.608 μg/mL, respectively. The results show that the procedure is accurate, precise, and reproducible (relative standard deviation < 1%), while being simple and less time consuming. The study concluded that the UV-spectrophotometric method could be used for the quantification of disodium edetate in pure form as well as in pharmaceutical formulations. PMID:23781446

  8. A Simple Method to Extract DNA from Hair Shafts Using Enzymatic Laundry Powder

    PubMed Central

    Liu, Jinchuan; Jiang, Xiaoling; Li, Sicong; Yang, Shuming; Chen, Ailiang

    2013-01-01

    A simple method to extract DNA from hair shafts was developed by using enzymatic laundry powder at the first step of the process. The whole extraction can be finished in less than 2 hours. The simple extraction reagent proposed here contains only two cheap components: ordinary enzymatic laundry powder and PCR buffer. After extraction, an ultra sensitive fluorescent nucleic acid stain, PicoGreen, was used for quantifying trace amount of double-stranded DNA in the solution extracted. For further validation of DNA extraction, four primers were employed to amplify DNA microsatellite loci. Both fluorescence spectroscopy and PCR results suggested that this method can extract DNA from hair shafts with good efficiency and repeatability. The study will greatly facilitate the use of hair shafts in future for DNA analyses on genome-wide scale. PMID:23922747

  9. Simple method to measure and analyze the fluctuations of a small particle in biopolymer solutions.

    PubMed

    Kuroda, Masafumi; Murayama, Yoshihiro

    2015-12-01

    We developed a simple method to investigate the motion of a small particle in biopolymer solutions. Using optical tweezers with low stiffness, a trapped probe particle fluctuates widely for a long time along the light axis, which reflects the rheological properties of the surrounding environment. We present a convenient technique for three-dimensional position tracking and the analysis focused on the distribution of particle positions and its variance in a given time interval. It allows us to obtain useful information about the dynamics of a small particle in a wide range from a free diffusive motion to a constrained motion with statistical significance. We applied this method to investigate the dynamics in collagen and DNA solutions; it was found that a collagen solution behaves as a simple viscous liquid and a DNA solution has apparent elasticity due to the slow relaxation of the configuration of molecules.

  10. A Simple Method to Measure Nematodes' Propulsive Thrust and the Nematode Ratchet.

    NASA Astrophysics Data System (ADS)

    Bau, Haim; Yuan, Jinzhou; Raizen, David

    2015-11-01

    Since the propulsive thrust of micro organisms provides a more sensitive indicator of the animal's health and response to drugs than motility, a simple, high throughput, direct measurement of the thrust is desired. Taking advantage of the nematode C. elegans being heavier than water, we devised a simple method to determine the propulsive thrust of the animals by monitoring their velocity when swimming along an inclined plane. We find that the swimming velocity is a linear function of the sin of the inclination angle. This method allows us to determine, among other things, the animas' propulsive thrust as a function of genotype, drugs, and age. Furthermore, taking advantage of the animals' inability to swim over a stiff incline, we constructed a sawteeth ratchet-like track that restricts the animals to swim in a predetermined direction. This research was supported, in part, by NIH NIA Grant 5R03AG042690-02.

  11. A Simple and Reliable Method for the Diagnosis of Ventriculoperitoneal Shunt Malfunction.

    PubMed

    Zhang, Hongri; Peng, Jinghua; Hao, Xiaowei; Guo, Xiaofan; Li, Gang

    2017-07-01

    To provide a simple and reliable method for the diagnosis of ventriculoperitoneal shunt malfunction. A total of 14 participants were enrolled in this study, consisting of 7 patients with suspected shunt malfunction and 7 control cases with apparent normal drainage. In all cases, 0.1 mL of 5% glucose solution was injected into the reservoir and 0.1 mL of cerebrospinal fluid was withdrawn from the reservoir 20 minutes later to measure glucose concentration. The glucose concentration in cerebrospinal fluid of the shunt malfunction group was greater than that of the control group (P < 0.05). The proposed method is reliable, safe, and relatively simple for the diagnosis of ventriculoperitoneal shunt malfunction and provides a reference for treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. A simple method to extract DNA from hair shafts using enzymatic laundry powder.

    PubMed

    Guan, Zheng; Zhou, Yu; Liu, Jinchuan; Jiang, Xiaoling; Li, Sicong; Yang, Shuming; Chen, Ailiang

    2013-01-01

    A simple method to extract DNA from hair shafts was developed by using enzymatic laundry powder at the first step of the process. The whole extraction can be finished in less than 2 hours. The simple extraction reagent proposed here contains only two cheap components: ordinary enzymatic laundry powder and PCR buffer. After extraction, an ultra sensitive fluorescent nucleic acid stain, PicoGreen, was used for quantifying trace amount of double-stranded DNA in the solution extracted. For further validation of DNA extraction, four primers were employed to amplify DNA microsatellite loci. Both fluorescence spectroscopy and PCR results suggested that this method can extract DNA from hair shafts with good efficiency and repeatability. The study will greatly facilitate the use of hair shafts in future for DNA analyses on genome-wide scale.

  13. Simple method for refining arabinan polysaccharides by alcohol extraction of the prune, Prunus domestica L.

    PubMed

    Hara, Yukari; Mizukawa, Hitomi; Yamamoto, Hirotaka; Ikami, Takao; Kato, Koji; Yabe, Tomio

    2013-01-01

    L-Arabinose is a useful sugar in the food industry. We demonstrate here simple methods for refining arabinan polysaccharides by alcohol extraction from prune, Prunus domestica L., as a source of L-arabinose. Alcohol-soluble polysaccharides were purified from a solution of prune extracted by 80% ethanol. After fractionating the polysaccharides by ion-exchange chromatography, arabinans were identified as mainly constituted by (1→5)-linked arabinofuranosyl units.

  14. Peer review of grant applications: a simple method to identify proposals with discordant reviews.

    PubMed

    Giraudeau, Bruno; Leyrat, Clémence; Le Gouge, Amélie; Léger, Julie; Caille, Agnès

    2011-01-01

    Grant proposals submitted for funding are usually selected by a peer-review rating process. Some proposals may result in discordant peer-review ratings and therefore require discussion by the selection committee members. The issue is which peer-review ratings are considered as discordant. We propose a simple method to identify such proposals. Our approach is based on the intraclass correlation coefficient, which is usually used in assessing agreement in studies with continuous ratings.

  15. A simple bioluminescent method for measuring D-amino acid oxidase activity.

    PubMed

    Bailey, T Spencer; Donor, Micah T; Naughton, Sean P; Pluth, Michael D

    2015-03-28

    D-Amino acid oxidase (DAO) plays important roles in regulating D-amino acid neurotransmitters and was recently identified as a key enzyme integral to hydrogen sulfide production from D-Cys. We report here the development of a simple biocompatible, bioluminescent method for measuring DAO activity based on the highly selective condensation of D-Cys with 6-hydroxy-2-cyanobenzothiazole (CBT-OH) to form D-luciferin.

  16. A simple spectrophotometric method for determination of sodium diclofenac in pharmaceutical formulations.

    PubMed

    Matin, A A; Farajzadeh, M A; Jouyban, A

    2005-10-01

    A new, simple, rapid and accurate spectrophotometric method is proposed for determination of sodium diclofenac (SD) in pharmaceutical preparations based on its reaction with concentrated nitric acid (63% w/v). The reaction product is a yellowish compound with maximum absorbance at 380 nm. The corresponding calibration curve is linear over the range of 1-30 mg l(-1), while the limit of detection is 0.46 mg l(-1).

  17. A simple method for reducing ovarian dose during megavoltage irradiation of the breast

    SciTech Connect

    Pennington, E.C.; Staples, J.; Jani, S.K. )

    1989-12-01

    Breast cancer in its early stages can be effectively treated with conservative surgery and irradiation. In young women who wish to subsequently bear children, reduction of ovarian dose during irradiation could be of great emotional significance. We describe a simple, convenient, cost-effective method by which ovarian dose was reduced from 18 cGy to 8 cGy during tangential irradiation of the intact breast with 6 MV photons.

  18. A SIMPLE METHOD FOR DETERMINATION OF CAFFEINE CONTENT IN TEA SAMPLES

    PubMed Central

    Venkatesh, Sama; Swamy, M.M.; Reddy, Y.S.R.; Suresh, B.; Sethuraman, M.

    1994-01-01

    The present communication describes a simple and modified colorimetric procedure for the estimation of caffeine content in both commercial and locally available tea samples. Comparative data of caffeine content in different brands of tea samples are shown here. The present method is no doubt an improvised procedure for estimating directly caffeine content from the tea extracts. A possible explanation to account for the variability in caffeine content in different samples is offered. PMID:22556672

  19. A simple and rapid nuclear staining method for Rhizoctonia solani Kuhn.

    PubMed

    Seema, M; Punith, B D; Devaki, N S

    2012-04-01

    We developed a modified staining technique using acridine orange to stain the nuclei of Rhizoctonia solani. Acridine orange solution was prepared in acetic acid buffer, pH 7.2. Staining for 15 min was critical for observing the nuclei. All of the isolates were found to be multinucleated. The nuclei appeared bright green with light orange background. This method is simple, rapid and reproducible.

  20. A simple method for importing multiple image files into PowerPoint.

    PubMed

    Sistrom, Chris; Honeyman-Buck, Janice

    2004-06-01

    We developed a method for automatically inserting a large number of images into a PowerPoint presentation document. We designed, tested, and now routinely use a simple macro program for importing all images contained in a single directory into a PowerPoint presentation. The complete text of the macro code is included in this article, and readers are encouraged to experiment with it.