preparation characterization and application as chemical sensors

... volume, and pore diameter of Nd2O3 and 30 wt.% KOH/Nd2O3 catalyst were measured The BET surface area as well as the pore volume decreased with loading potassium hydroxide, and this tendency was more ... other hand, the catalytic activity and activity sites also increase with the loading amount of KOH But, with further increase in the amount of loaded KOH, the basicity may decrease the surface basic ... (Nd2O3), potassium hydroxide (KOH), potassium iodide (KI), potassium bromate (KBrO3), potassium hydrogen phthalate (C8H5O4K) and potassium nitrate (KNO3) were obtained from Sinopharm Chemical Reagent...

Ngày tải lên: 05/05/2014, 08:42

... devices was measured The voltage of the dc source was fixed at 10 V and the current was measured by a pico-ammeter (Keithley 485) Figs 2a and b shows respectively the TEM images of the non-etched and ... for use as low-cost sensors In addition, it is much easier to prepare a device of chemical sensors by using a bundle of Si nanowires than using a single Si nanowire Here, we report the chemical ... two-crossed Si nanowires [12] On one hand, the NH3 gas and the water vapor may act as a chemical gate, which shifts the Fermi levels of the Si nanowires and 223 reduces the resistance of the...

Ngày tải lên: 16/03/2014, 15:08

... protein-bound tri- and diphosphate nucleotides Buffer conditions: 25 mM Tris/HCl at pH 7.4, 2.5 mM MgCl2 and mM DTE Nucleotide GTPase rate (10)5 min)1) RasGTP RasGTPcF RasGTPcS RasGTPcNH2 RasGppNHp RasGppCH2p ... magnesium ion was lower for GTPcNH2 and GTPcF For GTPcS the association constant was only two-fold smaller whereas for GTPcNH2 and GTPcF this constant was significantly smaller, namely 34-fold and 140-fold, ... GTP-binding protein Ras (residues 1–167) was synthesized in Escherichia coli and purified as described [16] Purified GDP, GTP, GTPcS and GppNHp reagents were purchased from Sigma and GppCH2p was ordered...

Ngày tải lên: 18/03/2014, 01:20

... voltage increased when the NH3 gas was inputted, which was due to the increase in resistances and decreased conductivities of Fig Varied sensitivities of S1 (a) and S2 (b) (annealed at different ... electrodes and platinum wires A Ni–Cr alloy through the tube was used as a heating filament The voltage of the sensor was measured indirectly by an external resistor in the testing circuit Gas sensitivity ... increased with increasing annealing temperature, and the particle sizes of S1 and S2 samples annealed at 150 8C were 5.3 nm and 4.7 nm, respectively, according to the Scherrer formula The S1 and...

Ngày tải lên: 21/03/2014, 12:17

... (99.5%) and ethyl alcohol were purchased as reagent-grade from Duksan Pure Chemical Co (Ansan-si, Gyeonggi-do, South Korea) and Daejung Chemical Co (Gwangju-si, Gyeonggi-do, South Korea) and were ... WO3, and TiO2 Because of the least band gap of fullerene (1.6 to 1.9 eV), hole and electron pairs were generated and separated on the interface of fullerene easily by visible light irradiation, and ... both the conduction band (CB) and the valence band (VB) of WO3 were higher than the CB and VB of TiO2 and fullerene When the hole and electron pairs were also generated and separated on the interface...

Ngày tải lên: 21/06/2014, 01:20

... Bovine, and Lysozyme Experimental Sodium tungstate, sodium borohydride, hydrochloric acid (37%), and ethanol were purchased from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China) and used as received ... typical procedure for the preparation of hollow Na0.15WO3 nanospheres is as follows: 40 mL of 0.25 M Na2WO4 aqueous solution was put in a 250 mL flask and the pH of the solution was adjusted to 6.8 using ... Brunauer–Emment–Teller (BET) specific area was measured on ASAP 2010 M/C surface area and porosimetry analyzer (Micromeritics Instrument Corporation, USA) based on N2 adsorption Results and Discussion In general,...

Ngày tải lên: 22/06/2014, 00:20

... Squibb (Brazil) and was initially prepared as a g/L stock solution in DMSO/methanol 1:1 Candida albicans ATCC 90028 was purchased from American Type Culture Collection (ATCC) and reactivated ... AmB and/ or CMC concentration are mM, 0.005 mM and mg.mL-1, respectively Alternatively, PDDA was replaced by PL (Table 2) At high P, the effect of increasing PL molecular weight was an increase ... charge on the assembly was not sufficient to substantially reduce fungus viability For final coverage with polylysines (PL) of increasing molecular weight at mg/mL PL, there was an increase in the...

Ngày tải lên: 11/08/2014, 00:22

... categorized into gas (vapor) phase fabrication and liquid phase fabrication Gas phase fabrication, such as pyrolysis or inert gas condensation, involves evaporation, supersaturation, gas-solid surface ... thickness Line (1) denotes the stable case, line (2) the unstable case and line (3) the metastable case.21 In contrast to polymer which dewets only above its glass transition temperature, metal can ... Sketch of effective interface potential as a function of film thickness Line (1) denotes the stable case, line (2) the unstable case and line (3) the metastable case.21……………………….…………………………… Figure...

Ngày tải lên: 09/09/2015, 11:26

... potentially useful as encapsulates for drugs, enzymes, protein, genes and catalysts, as transducers and dielectrics for electronics, as absorbent materials for sound and microwave, as contrast agents ... microspheres, and (e) and (f) Ag@air@P(MAA-co-DVB)-click-PNIPAM hybrid microrattles Figure 5.22 XPS wide-scan and C 1s core-level spectra of the (a and b) Au@SiO2@P(MAA-co-DVB), and (c and d) Au@SiO2@P(MAA-co-DVB)-click-PEG ... micro- and nanospheres with novel morphology and functions via a combination of inorganic and polymer synthesis and optimize the applications of these hollow polymer structures in drug delivery and...

Ngày tải lên: 10/09/2015, 08:40

... help in the work and it was a pleasure to work with them Special thanks to Prof Sow Chong Haur and his lab members for helping with the Raman and conductivity measurements Technical assistance from ... Mechanical Characterization 116 4.2.6 Electrical Characterization 117 4.3 Results and Discussion 117 v 4.3.1 Characterization of Graphene and Graphene/PVC Thin 117 Films 4.3.2 Mechanical Characterization ... methods of preparation, characterization techniques, properties, functionalization techniques and applications have been explained in Chapter Chapter deals with the isolation and characterization...

Ngày tải lên: 10/09/2015, 15:48

... for applications in electrocatalysis, as electrochemical sensors, electronic and photovoltaic devices In the following sections, the fabrication strategies, characterizations and potential applications ... electrochemical polymerization, chemical polymerization, and chemical vapor deposition The electrochemical and chemical polymerization methods will be introduced in this chapter while the chemical ... [122], poly-MTAPcs have been studied as sensors and electrocatalysts Sun and Tachikawa investigated the use of poly-CoTAPc and poly-CuTAPc films as biochemical sensors for the amperometric detection...

Ngày tải lên: 14/09/2015, 14:08

... (Fc/Fc+) redox couple, which was used as an internal standard The supporting electrolyte was 0.1 M Bu4NPF6 and analytical grade CH2Cl2, was used as the solvent and distilled over calcium hydride ... solvent was distilled out Water was added and extracted by CH2Cl2 The organic layer was washed by Na2CO3, Na2S2O3 and NaCl solution After 29 the solvent was distilled out, the crude was purified ... The mixture was stirred for h at room temperature and refluxed for another h The solvent was then distilled and the residue was neutralized with Na2CO3 After washing with water and brine, the...

Ngày tải lên: 14/09/2015, 14:09

... lipase immobilized in polypropylene was 770 times higher compared to lyophilized lipase powder and they interpreted that the higher activity of lipase upon immobilization was due to reduced mass ... glass, sol-gel glass, and silica gel Barros et al (1998) showed that the activity and enzyme loading of α-chymotrypsin immobilized in controlled pore glass was higher compare to polyamide and ... least twice and the error was found to be less than 15 % The activity was calculated on the basis of the formation of propyl ester by assuming that the extinction coefficients of the product and...

Ngày tải lên: 09/10/2015, 11:06

... devices 15 , and Molybdenum oxide is one such transition metal oxide and it has been reported to be a very popular material used for chemical industrial applications 16,17 In the vapor phased growth, ... temperature about 480 °C A fisher glass slide was placed on top of the Mo foil as illustrated in the schematic in Figure 2-1(b) The assembly was heated for hours before it was cooled down to room temperature ... Nanobelts and Characterization Techniques diffraction (SAED) pattern of the area showed that the sample was highly crystalline and the sample was orthorhombic with growth direction in [100] and [001]...

Ngày tải lên: 16/10/2015, 15:37

... micelles were able to bind As( V) species such as H2AsO 4and HAsO42- through electrostatic interaction, and later separated by ultrafiltration Optimization of As( V) rejection was studied by Iqbal et ... recover palladium as well as other PGMs, such as chemical precipitation and solvent extraction etc., often involve multiple-stage operations and can require huge amounts of input in chemicals (precipitants, ... research project, i.e the preparation and use of P4VP-based nanoadsorbents for palladium adsorption, as well as their separation and recovery with a membrane filtration system Based on the work done...

Ngày tải lên: 10/09/2015, 15:54

... Nalon-Chem (Asturias, Spain), with the composition given in Table 2.2 Catalyst characterization Catalyst pore structure and surface area was measured by nitrogen adsorption with a Micromeritics Asap ... rest being covered by iron and associated elements (titanium, sulfur, silicon and calcium) The presence of chlorine in the surface increased considerably, and was also associated with iron A small ... the /xm surface layer, defined as the product of the surface area and iron content measured from the EDX maps The decrease in iron, assumed to be the active phase as iron sulfide, fully explains...

Ngày tải lên: 23/09/2012, 14:46

... Acquisition “It’s as large as life, and twice as natural” —Lewis Carroll, “Through the Looking Glass” 1.1 Sensors, Signals, and Systems A sensor is often defined as a device that receives and responds ... of Measurements In this book, we use base units which have been established in The 14th General Conference on Weights and Measures (1971) The base measurement system is known as SI which stands ... Thermoelastic Electroelastic Thermomagnetic Thermooptic Photoelastic Other Chemical Chemical transformation Physical transformation Electrochemical process Spectroscopy Other Biological Biochemical...

Ngày tải lên: 31/12/2013, 22:48

... chromatography in combination with mass-based screening and functional screening Most of the a-conotoxins identified so far are relatively hydrophilic and hence tractable Mass-based screening entails searching ... and the cysteine residues alkylated in order to verify their identification Although there are standard procedures for reduction and alkylation, their application to conopeptide analysis and characterization ... by mass spectrometry and the lability of the sulfogroup in mass spectrometry analysis allows recognition of the modification, and differentiation of sulfotyrosine and phosphotyrosine [38] Characterization...

Ngày tải lên: 19/02/2014, 12:20

... that has similar applications to those of decaBDE (e.g., in both acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS) plastics as well as textile backcoating) and has been ... they are also used as flame retardants (as well as plasticizers and in paints and sealants) SCCPs have been found in water and sediments in the Great Lakes and elsewhere worldwide Houde et al (2008) ... retardant and one of two brominated chemicals in Firemaster 550, the primary replacement for pentaBDEs in polyurethane foam In addition to its uses as a flame retardant, TBPH is also marketed as a plasticizer...

Ngày tải lên: 05/03/2014, 20:20

... we report the chemical synthesis of AThTP and AThDP, their purification and their physicochemical characterization using positive ESI-MS, 1H-, 13 C- and 31P-NMR (Table 1), as well as molecular ... 202.5 MHz in D2O at pH 7.4 and 25 °C TMS and H3PO4 were used as references ThDP was a commercial preparation (Sigma-Aldrich), and ThTP, AThDP and AThTP were synthesized as described in Experimental ... yield was 5.3% for AThDP and 2.7% for AThTP (Table 2) The purity of the two preparations was checked by HPLC using UV and, after derivatization, fluorescence detection (Fig 4) Physicochemical characterization...

Ngày tải lên: 07/03/2014, 01:20