Electron reactivity in liquid hydrocarbon mixtures

1977 ◽  
Vol 55 (11) ◽  
pp. 2144-2155 ◽  
Author(s):  
Toshinori Wada ◽  
Kyoji Shinsaka ◽  
Hideki Namba ◽  
Yoshihiko Hatano
Keyword(s):  
Rate Constant ◽  
Room Temperature ◽  
Liquid Hydrocarbon ◽  
Electron Current ◽  
Hydrocarbon Mixtures ◽  
X Ray ◽  
Wide Range ◽  
Trapping Model ◽  
Ion Recombination ◽  
Quasifree State

The electron current in neopentane–n-hexane mixtures, produced by a few nanoseconds X-ray pulse in the presence of external electric field, has been observed in the nanosecond–microsecond range. The form of the time dependence of the electron current has been shown to vary with dose per pulse and is analysed accordingly. The electron mobilities μe are thereby determined in the mixtures. The rate constant of electron–ion recombination, kr, is proportional to the mobility over the wide range of μe The rate constant for electron scavenging, ks by CC14 varies with √μe; ks for C2H5Br shows a maximum for a mixture with the mole fraction of n-hexane, xh = 0.48. The results for ks obtained for the mixtures agree with those by Allen and co-workers for various neat hydrocarbons. Further, the mechanism of electron transport in non-polar liquids is discussed. Using experimental results for V0 and Ea for the mixtures (the energy of the electron in its quasifree state and the activation energy of μe, respectively) V0 is expressed by a linear function of Ea: V0 = −0.42 + 2.6Ea at room temperature and μe is correlated with V0 as an empirical formula μe = 125/[1 + 360 exp (15V0)] based on a trapping model.

scholarly journals A Highly Sensitive Room Temperature CO2 Gas Sensor Based on SnO2-rGO Hybrid Composite

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 522
Author(s):  
Zhi Yan Lee ◽  
Huzein Fahmi bin Hawari ◽  
Gunawan Witjaksono bin Djaswadi ◽  
Kamarulzaman Kamarudin
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
Hybrid Composite ◽  
Room Temperature ◽  
Co2 Gas ◽  
X Ray ◽  
Wide Range ◽  
Co2 Gas Sensor

A tin oxide (SnO2) and reduced graphene oxide (rGO) hybrid composite gas sensor for high-performance carbon dioxide (CO2) gas detection at room temperature was studied. Since it can be used independently from a heater, it emerges as a promising candidate for reducing the complexity of device circuitry, packaging size, and fabrication cost; furthermore, it favors integration into portable devices with a low energy density battery. In this study, SnO2-rGO was prepared via an in-situ chemical reduction route. Dedicated material characterization techniques including field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were conducted. The gas sensor based on the synthesized hybrid composite was successfully tested over a wide range of carbon dioxide concentrations where it exhibited excellent response magnitudes, good linearity, and low detection limit. The synergistic effect can explain the obtained hybrid gas sensor’s prominent sensing properties between SnO2 and rGO that provide excellent charge transport capability and an abundance of sensing sites.

scholarly journals Approach of Serial Crystallography

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 854
Author(s):  
Ki Hyun Nam
Keyword(s):  
Radiation Damage ◽  
Room Temperature ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Past ◽  
Wide Range ◽  
Experimental Limitation ◽  
Serial Crystallography ◽  
Collection Strategies

Radiation damage and cryogenic sample environment are an experimental limitation observed in the traditional X-ray crystallography technique. However, the serial crystallography (SX) technique not only helps to determine structures at room temperature with minimal radiation damage, but it is also a useful tool for profound understanding of macromolecules. Moreover, it is a new tool for time-resolved studies. Over the past 10 years, various sample delivery techniques and data collection strategies have been developed in the SX field. It also has a wide range of applications in instruments ranging from the X-ray free electron laser (XFEL) facility to synchrotrons. The importance of the various approaches in terms of the experimental techniques and a brief review of the research carried out in the field of SX has been highlighted in this editorial.

scholarly journals A green chemical route for the synthesis of Mn3O4 nanoparticles

2009 ◽  
Vol 7 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Zehra Durmus ◽  
Hüseyin Kavas ◽  
Abdulhadi Baykal ◽  
Muhammet Toprak
Keyword(s):  
Room Temperature ◽  
Particle Sizes ◽  
Chemical Route ◽  
Tem Analysis ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Wide Range ◽  
Long Range Interactions ◽  
Mn3o4 Nanoparticles

AbstractA novel environmental friendly, room temperature route using an ionic liquid 1-n-butyl-3-methylimidazolium hydroxide ([BMIM]OH) for the synthesis of Mn3O4 nanoparticles is presented. The product was characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Phase purity was confirmed by XRD, and X-ray line profile fitting determined a crystallite size of 42 ± 11 nm. TEM analysis revealed various morphologies. EPR measurements have indicated the existence of long-range interactions, due to the wide range of particle sizes and morphologies observed.

scholarly journals Pentamethylcyclopentadienylbis(ethen)eisen - ein 17e-Halbsandwichkomplex mit leicht verdrängbaren Ethenliganden / Pentamethylcyclopentadienylbis(ethene)iron - a 17e Halfsandwich Complex with Easily Displaceable Ethene Ligands

1995 ◽  
Vol 50 (3) ◽  
pp. 394-404 ◽  
Author(s):  
Klaus Jonas ◽  
Peter Klusmann ◽  
Richard Goddard
Keyword(s):  
Title Compound ◽  
Room Temperature ◽  
Iron Complexes ◽  
Starting Material ◽  
Dinuclear Complex ◽  
The Novel ◽  
Valuable Source ◽  
X Ray ◽  
Wide Range ◽  
Stabilizing Effect

The new room temperature stable halfsandw ich complex Cp*Fe(tmeda)Cl (2) has been synthesized by the 1:1 reaction of FeCl2(thf)1.5 with LiCp* in a mixture of THF and TMEDA at - 30 °C. 2 is an ideal starting material for the synthesis of a wide range of new iron complexes. Treatment of 2 with lithium sand in THF in the presence of COD or ethene followed by the addition of TMEDA yields the ferrates [Li(tmeda)][Cp*Fe(cod)] (3) or [Li(tmeda)][Cp*Fe(C2H4)2] (4). By delithiation with dichloroethane, 3 and 4 can be transformed into the novel 17 e iron complexes Cp*Fe(cod) (5) and Cp*Fe(C2H4)2 (6). 6 is extremely labile. Since the ethene ligands can be easily displaced, the title compound is a synthetically valuable source of the Cp*Fe fragment. Whereas the photochemically generated 17e dicarbonyl species CpFe(CO)2 rapidly recombines to give the dimer [CpFe(CO)2]2, the isoelectronic 6 is stable in ethene saturated pentane for several days at 0 °C. Without the stabilizing effect of ethene (in pure pentane or under vacuum ), 6 loses ethene to give the dinuclear complex (Cp*Fe)2(C2H4)2 (8) irreversibly. The structure of 8 has been characterized by X -ray analysis.

X-Ray Fluorescence Analysis of High Z Materials with Mercuric Iodide Room Temperature Detectors

1980 ◽  
Vol 24 ◽  
pp. 303-309 ◽  
Author(s):  
J. Nissenbaum ◽  
A. Holzer ◽  
M. Roth ◽  
M. Schieber
Keyword(s):  
Solid State ◽  
Energy Resolution ◽  
Room Temperature ◽  
Fluorescence Analysis ◽  
Industrial Applications ◽  
Mercuric Iodide ◽  
Portable Xrf ◽  
X Ray ◽  
State Radiation ◽  
Wide Range

AbstractMercuric iodide HgI2 room temperature solid state radiation spectrometers having 4% energy resolution at 100 KeV detected the x-ray fluorescence (XRF) of the K shell of intermediate and high Z elements. The excitation of the K shells which emit XRF more energetic than 60 KeV was achieved with 7mCi collimated 57Co and for XRF less energetic than 60 KeV the excitation was done with a 10mCi 241Am source. The K shell XRF spectra of a 1:1 mixture of U and Th, and also of the single elements of Au, Tb, Ba, Ag, Mo, and Rb are shown. The results prove the feasibility of developing mercuric iodide portable XRF spectrometers which operate at room temperature and which have a wide range of geochemical and industrial applications.

scholarly journals Studies of Optical, Dielectric, Ferroelectric, and Structural Phase Transitions in 0.9[KNbO3]-0.1 [BaNi1/2Nb1/2O3−δ]

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Blanca Yamile Rosas ◽  
Alvaro A. Instan ◽  
Karuna Kara Mishra ◽  
S. Nagabhusan Achary ◽  
Ram S. Katiyar
Keyword(s):  
Phase Transitions ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Structural Phase ◽  
Cubic Phase ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Wide Range

The compound 0.9[KNbO3]-0.1[(BaNi1/2Nb1/2O3−δ] (KBNNO), a robust eco-friendly (lead-free) ferroelectric perovskite, has diverse applications in electronic and photonic devices. In this work, we report the dielectric, ferroelectric, and structural phase transitions behavior in the KBNNO compound using dielectric, X-ray diffraction, and Raman studies at ambient and as a function of temperature. Analyses of X-ray diffraction (XRD) data at room temperature (rtp) revealed the orthorhombic phase (sp. Gr. Amm2) of the compound with a minor secondary NiO cubic phase (sp. Gr. Fm3m). A direct optical band gap Eg of 1.66 eV was estimated at rtp from the UV–Vis reflectance spectrum analysis. Observation of non-saturated electric polarization loops were attributed to leakage current effects pertaining to oxygen vacancies in the compound. Magnetization studies showed ferromagnetism at room temperature (300 K) in this material. XRD studies on KBNNO at elevated temperatures revealed orthorhombic-to-tetragonal and tetragonal-to-cubic phase transitions at 523 and 713 K, respectively. Temperature-dependent dielectric response, being leaky, did not reveal any phase transition. Electrical conductivity data as a function of temperature obeyed Jonscher power law and satisfied the correlated barrier-hopping model, indicating dominance of the hopping conduction mechanism. Temperature-dependent Raman spectroscopic studies over a wide range of temperature (82–673 K) inferred the rhombohedral-to-orthorhombic and orthorhombic-to-tetragonal phase transitions at ~260, and 533 K, respectively. Several Raman bands were found to disappear, while a few Raman modes such as at 225, 270, 289, and 831 cm−1 exhibited discontinuity across the phase transitions at ~260 and 533 K.

scholarly journals Adsorption Capacity of Smectite Clay and Its Thermal and Chemical Modification for Two Anionic Dyes: Comparative Study

2021 ◽  
Vol 232 (2) ◽  
Author(s):  
Magdalena Pajak
Keyword(s):  
Experimental Data ◽  
Adsorption Capacity ◽  
Room Temperature ◽  
Dye Adsorption ◽  
Anionic Dyes ◽  
Smectite Clay ◽  
Oh Groups ◽  
X Ray ◽  
Reactive Red 198 ◽  
Wide Range

AbstractThe present research evaluates the influence of modification of smectite clay (BC) on its adsorption capacity of anionic dyes from aqueous solutions. Thermal (BC 250), acidic (BC H2SO4), and alkaline (BC NaOH) modification of clay was carried out. The clays were characterized by X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Adsorption of dyes was investigated by batch experiments at room temperature (23 ± 2 °C), a wide range of initial dye concentrations (1–1000 mg/dm3), and an adsorbent dose of 50 g. All modifications increased the clay’s adsorption capacity for Reactive Red 198, in the order BC H2SO4 > BC NaOH > BC 250 > BC; it was 10.32, 5.06, 3.32, and 2.92 mg/g, respectively. Acid and thermal modification of the clay increased its adsorption capacity for Acid Red 18, in the series BC H2SO4 > BC 250 > BC > BC NaOH; it was 3.07, 2.66, 2.16, and 1.28 mg/g, respectively. The experimental data were analyzed by Freundlich, Langmuir, Dubinin–Radushkevich, and Sips isotherms, using nonlinear regression. The experimental data best fitted the Sips isotherm. Taking into account the structure of the adsorbent and adsorbates and the results obtained, it can be concluded that the dyes were probably bound through chemisorption, by forming hydrogen bonds between Si–OH and Al–OH groups in the clay and –NH, –NH2, and –OH groups in the dyes. From the results obtained, it can be concluded that smectite clay is a promising material for dye adsorption.

scholarly journals Cu(OH)x-clay catalyst promoted synthesis of 4,5-dihydro-1,2,4-oxadiazole at room temperature

2018 ◽  
Vol 7 (6) ◽  
pp. 487-492 ◽  
Author(s):  
Bashir Ahmad Dar ◽  
Zahed Zaheer ◽  
Samreen Fatema ◽  
Mazahar Farooqui
Keyword(s):  
Room Temperature ◽  
Functional Group ◽  
Cycloaddition Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Efficient Scheme ◽  
Clay Catalyst ◽  
Microscopy Techniques

Abstract An easy and efficient scheme is described and designed for the preparation of 4,5-dihydro-1,2,4-oxadiazole using recyclable Cu(OH)x-clay heterogeneous catalyst at room temperature. The cycloaddition reaction is carried out between imine and oxime using an easy protocol where nitrile oxides are produced in situ from aldoximes and reacted with imines to form 1,2,4-oxadiazolines in good yield and tremendous purity. Cu(OH)x-clay catalyst shows excellent catalytic activity for the formation of 1,2,4-oxadiazole. This technique is practically uncomplicated, inexpensive, and excellent with a wide range of functional group tolerance to generate structurally different 1,2,4-oxadiazoles. The prepared catalyst was investigated by X-ray diffraction and scanning electron microscopy techniques. The final products of the synthesized compound were characterized by Fourier transform infrared, mass, and nuclear magnetic resonance spectroscopies.

Temperature-Dependent Structural Disintegration of Delafossite CuFeO2

2009 ◽  
Vol 1183 ◽  
Author(s):  
Shojan P Pavunny ◽  
Ashok Kumar ◽  
Reji Thomas ◽  
Nishit M Murari ◽  
Ram S Katiyar
Keyword(s):  
Raman Spectra ◽  
Room Temperature ◽  
Single Phase ◽  
Significant Shift ◽  
Gravimetric Analysis ◽  
Temperature Dependent ◽  
Thermo Gravimetric ◽  
Xps Spectra ◽  
X Ray ◽  
Wide Range

AbstractSingle phase delafossite p-type CuFeO2 (CFO) semiconductor was synthesized in bulk by modified solid state reaction technique. X-ray diffraction (XRD) and X-ray photo spectroscopy (XPS) studies suggest single phase CFO at room temperature. The energy dispersive X-ray spectroscopy (EDX) revealed that the atomic ratio of Cu and Fe is 1:1. The XPS spectra showed two intense Cu 2p3/2 and 2p1/2 peaks at 932.5 eV and 952 eV suggesting Cu is in +1 state. The temperature dependent Raman spectra of CFO displayed two intense modes at 349 cm-1 and 690 cm-1 at room temperature that matched with other delaffosite structures. The temperature dependent Raman spectra showed significant shift in both Raman active modes to lower frequency side. We observed the disappearance of pure CFO Raman active modes above 750 K and the appearance of new peaks related to CuO compounds, indicating disintegration of CFO starting above 750 K which almost completed above 1100 K. The temperature dependent thermo-gravimetric analysis indicates change in CFO mass above 750 K with wide range of differential thermo-gravimetric slope suggests disintegration started above 750 K and completed at 1100 K. Raman spectra, XPS, and XRD of disintegrated CFO matched well with the Raman spectra, XPS and XRD of CuO and CuFe2O4 confirmed its disintegration above 750 K in air.

Varistor Beahavior in Lead Based Perovskite Comounds

2001 ◽  
Vol 685 ◽  
Author(s):  
Seema Sharma ◽  
R.N.P. Choudhary
Keyword(s):  
Room Temperature ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Current Voltage ◽  
Wide Range ◽  
Ptcr Effect ◽  
Different Temperatures ◽  
Structure And Microstructure ◽  
Scanning Electron

Polycrystalline samples of Pb(Cd1/2W1/2)O3 and Pb(Mo1/2W1/2)O3 were synthesized by a high-temperature solid-state reaction technique. Preliminary crystal structure and microstructure of the compounds at room temperature were studied using X-ray diffraction (XRD) technique and Scanning electron microscopy (SEM), respectively. The dielectric permittivity (⊏) and losstangent (tan ⊏) of the compounds were obtained both as a function of frequency(103-104Hz) atroom temperature and temperature (30-3200C) at 10 kHz. Both the ac and dc conductivity have been studied over a wide range of temperature. The current– voltage (I-V) characteristics of the compound studied at different temperatures reveal that the Pb(Cd1/2W1/2)O3 also has excellent varistor behavior. A PTCR effect and NTCR effect was exhibited by Pb(Cd1/2W1/2)O3 and Pb(Cd1/2Mo1/2)O3 respectively.

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