Wavenumber Shifts Research Articles

Structural Properties of Erbium Doped Tellurite Glass Embedded with Natural Ferrite Oxide Nanoparticles

Natural ferrite oxide nanoparticles (NPs) embed with tellurite glasses ((89-x) TeO2-10ZnO-1Er2O3-(x)Fe3O4, (x = 0 – 0.8 mol %)) were prepared by conventional melt quenching method to study the influence of the Fe3O4 NPs concentration on the stuctural properties of the glass. Studies on these glassy materials characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and RAMAN spectroscopic measurements are presented. It is observed that the amorphous nature of the glass is confirmed by x-ray diffraction. The FTIR studies support the formation of Te-O-Fe linkages. The FTIR spectra reveal modification in network structures evidenced from vibrational wave-number shifts of TeO4 and TeO3 structural units. Raman spectroscopy have been manipulated to observe the structural modification of [TeO4] trigonal bipyramidal structural unit.

Clinical and radiographic periodontal parameters and release ofcollagen degradation biomarkers in naswar dippers.

The aim of the present study was to compare clinical periodontal parameters and to assess the release of C-telopeptides pyridinoline cross-links (ICTP) and C-terminal crosslinked telopeptide (CTX) from gingival collagen of naswar (NW) and non-naswar (control) dippers. Eighty-seven individuals (42 individuals consuming NW and 45 controls) were included. Clinical (plaque index, bleeding on probing, probing depth and clinical attachment loss) and radiographic (marginal bone loss) periodontal parameters were compared among NW and control groups. Gingival specimens were taken from subjects in NW and control groups, assessed for ICTP and CTX levels (using ELISA) and analyzed using micro-Raman spectroscopy. The significance of differences in periodontal parameters between the groups was determined using Kruskal-Wallis and Mann-Whitney U tests. The percent loss of dry mass over exposure time and the rate of release of ICTP and CTX from all groups were compared using the paired t-test to examine the effects of exposure time. Clinical and radiographic periodontal parameters were significantly higher in the NW group than the control group (P<.01). In the Raman spectrum, the strongest and sharpest band occurred at 1260cm-1 amongst NW users. A Raman band at Amide I was observed with slight shifts in wave numbers. The rate of ICTP and CTX release was significantly higher in subjects from the NW group compared with those from the control group (P<.05). Both factors, the type of groups and time, had a significant effect on release of ICTP and CTX (P<.05). Within the limits of the present study, it may be concluded that clinical and radiographic periodontal parameters were worse among subjects in the NW group than in those of the control group. There is a higher degree of collagen breakdown in the connective tissue of subjects in the NW group as a result of naswar usage.

Facile wet chemical route synthesis, characterization and spectroscopic analysis of yttrium-doped lanthanum phosphate nanoparticles

Pure and yttrium-doped lanthanum phosphate nanoparticles were successfully prepared through a simple one-step co-precipitation method. The phase, morphology and composition of Y x La1 − x PO4 powders with varying dopant concentration (x = 0.00, 0.01, 0.03, 0.05) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) supplemented with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). XRD analysis reveals the nanocrystalline nature with monoclinic monazite crystal system. SEM and TEM micrographs indicate the formation of ultrafine particles depicting spherical morphology with slight agglomeration and cluster formation. Fourier transform infrared spectroscopy (FTIR) signifies the presence of water vibration modes in a particular wave number along with phosphate group and a slight shift in wave numbers when yttrium is induced into lanthanum phosphate. Thermogravimetric analysis (TGA) reveals that the structural phase transition takes place above 800 °C. Raman spectra gives insight into the order–disorder in the system and shows relevant peaks for symmetric and anti-symmetric of PO4 3−, O–P–O bending mode, rare earth—oxygen vibrations. The fluorescence spectra of the grown compositions were investigated. The results show strong emission peaks at 270 nm excitation, whose intensity increases along with the increasing dopant concentration. Ultraviolet (UV) spectroscopy reveals that the absorption bands lie in the ultraviolet range and the bands are particularly sensitive to the incorporation of dopant ion, i.e., with effect of doping bands shift towards the lower wavelength side.

The Effect of Phosphatation and Granulation Zeolite in the Adsorption of Cr(VI)

The purpose of this research to study effect of contact time on adsorption of Cr(VI) ion using Granules Alumino Silico Phosphate (GASP) and the effect of Cr (VI) concentration on adsorption capacity at GASP. The GASF synthesis process is carried out in several main stages: 1) activation of zeolite with addition of HCl, 2) zeolite phosphatation with addition of NH 4 H 2 PO 4 ratio Si/P = 1/6 at 235ᴼC for 5 hours, 3) how make GASP with addition of zeolite phosphate (Alumino Silicone Phosphate) and chitosan gel with a syringe pump speed of 50 mL/min. GASP is characterized using XRF, FT-IR and SAA. The contact time effect is tested using 0.1 g of GASF in K 2 CrO 4 100 mg/L with a contact time variation of 0.5; 1.0; 1.5; 2.0 and 2.5 hours. The concentration effect on adsorption capacity is tested out using 0.1 g of GASP in K 2 CrO 4 with concentration variation 25, 50, 75, 100 and 150 mg / L for 2 hours (optimum contact time). The adsorption capacity can be determined using the Langmuir equation. XRF characterization results showed a decrease in SiO 2 levels of 18.10% and Al 2 O 3 by 2.2% after phosphatation process. FTIR characterization results indicate the presence of O-H, N-H and C-H chitosan on absorption bands 1-3. The success of the phosphatation process was evidenced by the shift of wave numbers to the lower regions in the bands 7, 9 and 12 the absorption of tetrahedral silica and alumina shifted to bands 8, 10 and 13 tetrahedral phosphate uptake in accordance with Hooke's law. The result of the research showed that the optimum contact time occurred in the adsorption process for 2 hours. The concentration variation was directly proportional to the increase of the adsorbed Cr (VI) ion mass. The presence of phosphatation and chitosan addition process can increase the value of adsorption capacity by 48,077 mg / g.

Single-Cell Growth Rates in Photoautotrophic Populations Measured by Stable Isotope Probing and Resonance Raman Microspectrometry.

A new method to measure growth rates of individual photoautotrophic cells by combining stable isotope probing (SIP) and single-cell resonance Raman microspectrometry is introduced. This report explores optimal experimental design and the theoretical underpinnings for quantitative responses of Raman spectra to cellular isotopic composition. Resonance Raman spectra of isogenic cultures of the cyanobacterium, Synechococcus sp., grown in 13C-bicarbonate revealed linear covariance between wavenumber (cm−1) shifts in dominant carotenoid Raman peaks and a broad range of cellular 13C fractional isotopic abundance. Single-cell growth rates were calculated from spectra-derived isotopic content and empirical relationships. Growth rates among any 25 cells in a sample varied considerably; mean coefficient of variation, CV, was 29 ± 3% (σ/), of which only ~2% was propagated analytical error. Instantaneous population growth rates measured independently by in vivo fluorescence also varied daily (CV ≈ 53%) and were statistically indistinguishable from single-cell growth rates at all but the lowest levels of cell labeling. SCRR censuses of mixtures prepared from Synechococcus sp. and T. pseudonana (a diatom) populations with varying 13C-content and growth rates closely approximated predicted spectral responses and fractional labeling of cells added to the sample. This approach enables direct microspectrometric interrogation of isotopically- and phylogenetically-labeled cells and detects as little as 3% changes in cellular fractional labeling. This is the first description of a non-destructive technique to measure single-cell photoautotrophic growth rates based on Raman spectroscopy and well-constrained assumptions, while requiring few ancillary measurements.

Co-precipitation synthesis, characterization, thermal and spectroscopic analysis of gadolinium-doped neodymium phosphate nanoparticles

Ultrafine particles of pure and gadolinium (Gd)-doped neodymium phosphate nanoparticles with general formulae GdxNd1−xPO4 where x = 0.00, 0.01, 0.03, 0.05 were prepared by wet chemical co-precipitation technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and thermogravemetric analysis (TG) were performed to characterize the samples. XRD analysis suggests that the material belongs to the monoclinic crystal system. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) studies depict that all the as-synthesized samples show spherical morphology with the formation of slight clusters. The energy-dispersive X-ray analysis (EDAX) gives elemental composition present in the grown material. FTIR analysis determines the presence of various atomic bonds within a molecule, and the present study depicts the presence of water molecule along with the phosphate group and a slight shift in wave number with doping. Thermogravemetric analysis (TG) suggests that the structural phase transition takes place above 800 °C. Raman spectra give insight into the order–disorder in the system and show relevant peaks for symmetric and antisymmetric of PO 4 3 , O–P–O bending mode, rare earth–oxygen vibrations. UV spectroscopy depicts that various absorption bands fall in the ultraviolet range and the absorption edge shifts toward the lower wavelength side (blue shift) with increase in dopant concentration.

Fine Molecular Tuning of Diketopyrrolopyrrole-Based Polymer Semiconductors for Efficient Charge Transport: Effects of Intramolecular Conjugation Structure

To improve the charge carrier mobility of diketopyrrolopyrrole donor–acceptor copolymer semiconductors, the length of the donor building block is controlled using vinylene moieties, and its effects on crystalline structure and charge transport are systematically studied. We synthesize P29-DPP-TBT with two vinylene linkages between thiophene units and compare it with P29-DPP-TVT with single vinylene linkage. Density functional theory calculations predict enhanced backbone planarity of P29-DPP-TBT compared to P29-DPP-TVT, which can be related to the increased conjugation length of P29-DPP-TBT as proved by the increased free exciton bandwidth extracted from UV–vis absorption spectra and the wavenumber shift of the C–C peaks to higher values in Raman spectra. From two-dimensional grazing incident X-ray diffraction studies, it is turned out that the paracrystalline disorder is lower in P29-DPP-TBT than in P29-DPP-TVT. Near-edge X-ray absorption fine structure spectroscopy reveal that more edge-on structure of ...

Absorption cross sections of 13C ethane and propane isotopologues in the 3 µm region

To the best of our knowledge, we present first-time measurements of the absorption cross sections of 13C ethane and propane isotopologues in the spectral region around 3000cm-1. The spectra of 13C12CH6, 13C2H6 and 13C12C2H8 have been recorded at approximate room temperature and atmospheric pressure for concentrations between 0.325% and 0.750% in nitrogen using an FTIR spectrometer with a resolution of 0.5cm-1. For calibration purposes an ethane and a propane spectrum each obtained with a natural isotopologue sample were compared to respective spectra from the Pacific Northwest National Laboratory (PNNL). The spectrum of 13C12CH6 is shifted between 3.5cm−1 and 3.8cm-1 towards smaller wavenumbers compared to 12C2H6. The peaks of 13C2H6 ethane were shifted between −4.4cm-1 and −7.2cm-1 relatively to the corresponding 12C peaks. 13C12C2H8 shows a wavenumber shift of −2cm−1 for the largest central peak at 2965.5cm-1 and −6.5cm-1 for the second largest peak at 2955cm-1. The newly determined cross sections will allow for the first time isotopologue-sensitive spectral analyses of ethane and propane in this spectral region and may be used for applications from atmospheric and planetary research to natural gas exploration.

Portable Raman verification and quantification of jade in Olmec ceremonial axes from El Manatí, Veracruz, Mexico

The El Manatí archaeological site in Veracruz State, Mexico, is famous for its deposits of ceremonial stone axes and beads from the Olmec culture. Some of these have been considered to be in jadeite‐jade, but this rock type in these artefacts has never before been physico‐chemically verified. A portable Raman spectrometer was employed in situ inside the Centro‐INAH Veracruz reserve for this remote analytical operation of non‐destructive direct hand‐held analysis to identify some of the mineral species present. The key points of interest were as follows: which objects can correctly be called ‘jade’ because they contain the high‐pressure minerals jadeite or omphacite and, if so, with what mol. % Jd (Jd%) in the solid‐solution jadeite–diopside–hedenbergite. The Jd% value was then quantified from the wavenumber shift of the symmetric Si–O–Si Raman vibration band. Although some artefacts did not yield any usable Raman spectra, exploitable spectra were obtained from 41 stone axes or beads. Jadeite was found in 13 artefacts and omphacite in another 11. Jd% varied from 95 to 38% such that many of these jades are actually omphacite‐jade rather than jadeite‐jade. The complicated terminology of jades is thus re‐examined. A partial correlation is shown to exist between the Jd% value and the density of the artefacts. These results provide important, hitherto unknown, mineralogical data for archaeologists studying artefacts at different horizons at different sites of Mesoamerican cultures. These results also allow these artefacts to be now labelled correctly in their Museum reserve or exhibition display. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Study of Oblique Propagating Whistler Mode Waves in Presence of Parallel DC Electric Field in Magnetosphere of Saturn

In this paper whistler mode waves have been investigated in magnetosphere of Saturn. The derivation for perturbed distribution function, dispersion relation and growth rate have been determined by using the method of characteristic and kinetic approach. Analytical expressions for growth rate and real frequency of whistlers propagating oblique to magnetic field direction are attained. Calculations have been performed at 6 radial distances in plasma sheet region of Saturn’s magnetosphere as per data provided by Cassini. Work has been extended for bi-Maxwellian as well as Loss-cone distribution function. Parametric analysis show that temperature anisotropy, increase in number density, energy density and angle of propagation increases the growth rate of whistler waves along with significant shift in wave number. In case of Loss-cone distribution, increase in growth rate of whistlers is significantly more than for bi-Maxwellian distribution function. Generation of second harmonics can also be seen in the graphs plotted. It is concluded that parallel DC field stabilizes the wave and temperature anisotropy, angle of propagation, number density and energy density of electrons enhances the growth rate. Thus the results are of importance in analyzing observed VLF emissions over wide spectrum of frequency range in Saturnian magnetosphere. The analytical model developed can also be used to study various types of instabilities in planetary magnetospheres.

Adsorption of Water to Collagen as Studied Using Infrared (IR) Microspectroscopy Combined with Relative Humidity Control System and Quartz Crystal Microbalance.

Infrared (IR) microspectroscopy combined with a quartz crystal microbalance (QCM) together with an original relative humidity (RH) control system has been developed for studying water adsorption on a collagen film. The adsorbed water weights measured by QCM are almost similar for wetting and drying processes at 28 ℃, indicating that the collagen film is close to the water adsorption/desorption equilibria. A broad OH + NH stretching band area (3000-3700 cm-1) in the IR spectra of the collagen film increased linearly with the adsorbed weight until about 1.2 μg/8.0 μg dry collagen film at relative humidity (RH) = 40%, while at higher RH (60%, 80%), the band area deviates from the linear trend to the lower side, due to viscoelasticity and others. The OH + NH band can be simulated by four Gaussian components at 3440, 3330, 3210, and 3070 cm-1 with the relatively constant band areas of 3330 and 3070 cm-1 components due to amide A and B (NH) for increasing and decreasing RH. Bound water (3210 cm-1 component: short H bond) constitutes around 70% of total water (3440 + 3210 cm-1 band areas) at RH = 4.9% but decreases to 23% at RH = 80.3%, where free water (3440 cm-1 component: long H bond) becomes dominant over 70%. The peak shifts of C=O stretching (Amide I) and N-H bending (Amide II) can be understood by increasing hydrogen bonding of water molecules (bound water) bound to peptides at lower RH. The higher wavenumber shifts of CH stretching can be due to the loose binding of water molecules (free water) to aliphatic chains on the collagen surface, especially at higher RH. The present combined QCM-IR method is useful for studying amounts and natures of water adsorbing on biomolecules.

Physicochemical properties of nanocomposite: Hydroxyapatite in reduced graphene oxide

Graphene oxide (GO) based nanocomposites have gained considerable attention in the field of material science due to their excellent physicochemical and biological properties. Incorporation of nanomaterials into GO sheets prevents the formation of π–π stacking bond thereby giving rise to composites that show the improved properties compared to their individual counterparts. In this work, reduced graphene oxide (rGO) - hydroxyapatite (HAP) nanocomposites were synthesized by ultrasonic method. Increasing the c/a ratio of HAP in the diffraction pattern of rGO/HAP nanocomposites indicates the c-axis oriented grown HAP nanorods interacting with rGO layers. Shift in wavenumber (15cm−1) and increase of full width at half maximum (45cm−1) of G band in Raman spectra of the rGO/HAP nanocomposites are observed and attributed to the tensile strain induced due to the intercalated HAP nanorods between the rGO layers. Atomic force microscopy (AFM) and phase imaging studies revealed the intercalation of HAP nanorod with diameter 30nm and length 110–120nm in rGO sheets was clearly perceived along with improved elasticity compared to pristine HAP. 13C-NMR results proved the synergistic interaction between both components in rGO/HAP nanocomposite. The novel properties observed and the microscopic mechanism responsible for this are a result of the structural modification in rGO layers brought about by the intercalation of HAP nanorods.

Study of whistler mode waves for ring distribution function in Saturn’s magnetosphere

In present paper whistler mode waves in magnetosphere of Saturn have been investigated. Linear properties of ring velocity distribution function are used to derive dispersion relation for whistler mode waves in ambient magnetic field of Saturn in extended plasma sheet of planet’s magnetosphere. The derivation for perturbed distribution function, dispersion relation and growth rate have been determined by using the method of characteristic and kinetic approach. Analytical expressions for growth rate and real frequency of whistlers propagating parallel to magnetic field direction are attained. The analysis shows that temperature anisotropy, increases in number density and energy density increases the growth rate of whistler waves along with significant shift in wave number. It has been shown that whistler mode waves have grown due to loss of perpendicular kinetic energy of ring electrons. Calculations have been performed at two radial distances in Saturn’s magnetosphere. The results are of importance in analyzing observed VLF emissions over wide spectrum of frequency range in Saturnian magnetosphere. The analytical model developed can also be used to study various types of instabilities in planetary magnetospheres.

Mode-selective phonon excitation in gallium nitride using mid-infrared free-electron laser

The single-phonon mode was selectively excited in a solid-state sample. A mid-infrared free-electron laser, which was tuned to the target phonon mode, was irradiated onto a crystal cooled to a cryogenic temperature, where modes other than the intended excitation were suppressed. An A1(LO) vibrational mode excitation on GaN(0001) face was demonstrated. Anti-Stokes Raman scattering was used to observe the excited vibrational mode, and the appearance and disappearance of the scattering band at the target wavenumber were confirmed to correspond to on and off switching of the pump free-electron laser and were fixed to the sample vibrational mode. The sum-frequency generation signals of the pump and probe lasers overlapped the Raman signals and followed the wavenumber shift of the pump laser.

Preparation of polyoxometalate compound (NH4)6(β-P2W18O62)/SiO2 by sol-gel method and its characterization

Preparation of polyoxometalate compound of (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O supported with silica derived from the hydrolysis of tetraethyl orthosilicate by sol-gel method has been conducted. The compound was synthesized and characterized using FT-IR spectrophotometer, crystallinity using XRD analysis and the determination of acidity via quantitatively and qualitatively. Qualitative analysis was performed using ammonia and pyridine adsorption and quantitative analysis using potentiometric titration. FT-IR spectrum of (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O appeared in wavenumber 786.96 cm -1 (W-O C -W), 918.12 cm -1 (W-O e -W), 964.41 cm -1 (W=O), 1087.85 cm -1 (P-O), 3572.17 cm -1 (O-H), 1404.18 cm -1 (N-H) reinforced with wavenumber 1612.49 cm -1 with show vibration NH dari NH + , and to (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O/SiO 2 appears in wavenumbers 794.67 cm -1 (W-O c -W), 918.12 cm -1 (W-O e -W), 1049.28 cm -1 (W=O), 1087.85 cm -1 (P-O), 3564.15 cm -1 (O-H), 470.63 cm -1 (Si-O). Diffraction pattern of (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O and (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O/SiO 2 compound show high crystanillity. The acidic properties showed (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O/SiO 2 more acidic than (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O. Analysis of the effect of temperature on the stability of the compounds polyoxometalate (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O/SiO 2 show that the temperature of 600ºC the shift in wavenumbers of the compounds caused by vibration W=O, W-O C -W, W-O e -W has been lost. This shows that at a temperatures of 600ºC on heating can cause changes in the structure of polyoxometalate (NH 4 ) 6 (β-P 2 W 18 O 62 )nH 2 O/SiO 2. Keywords : (NH 4 ) 6 (β-P 2 W 18 O 62 ).nH 2 O, Polyoxometalate, SiO 2

Infrared spectra of HSCS+, c-HSCS, and HCS2- produced on electron bombardment of CS2 in solid para-hydrogen.

We report infrared (IR) spectra of HSCS+, c-HSCS, HCS2-, and other species produced on electron bombardment of a mixture of CS2 and para-hydrogen (p-H2) during deposition at 3.2 K. After maintenance of the deposited matrix in darkness for 12 h, the intensities of the absorption lines of HSCS+ at 2477.2 (ν1), 1525.6 (ν2), and 919.6 cm-1 (ν3) decreased through neutralization of HSCS+ with trapped electrons. During this period, the intensities of the lines of HCS2- at 2875.7 (ν1), 1249.9 (ν5), 1003.2 (ν6), and 814.3 cm-1 (ν4) increased due to reaction between H and CS2-. The intensities of the lines observed at 2312.7 and 889.0 cm-1, which are assigned to the c-HSCS radical, increased after maintenance in darkness and greatly diminished after irradiation at 373 nm. The IR spectra of HSCS+, HCS2-, and c-HSCS are reported for the first time. The IR absorption lines of the t-HSCS radical, t-HC(S)SH, and c-HC(S)SH were also identified; their wavenumbers are similar to those reported for these species in an Ar matrix. The corresponding spectra of the 13C, 34S, and D isotopic variants of these species were observed. The assignments were made according to the expected chemical behavior, predicted potential energies of associated reactions, and a comparison of observed and predicted wavenumbers and their 13C, 34S, and D isotopic ratios. In contrast to the observed significant red shifts of the OH-stretching wavenumbers of HOCO+ and HOCS+ in solid p-H2 compared to those in the gaseous phase due to proton sharing with H2, the wavenumber of the HS-stretching mode of HSCS+ in solid p-H2 (2477.2 cm-1) is similar to the anharmonic wavenumber of HSCS+ (2424 cm-1) predicted with the B3LYP/aug-cc-pVTZ method, indicating that the sharing of a proton between HSCS+ and neighboring H2 molecules is insignificant.

Compton Scattering of a Vortex Light Beam

Energy-momentum conservation laws in Compton scattering are analyzed. The conservation of total angular momentum is applied to a general formula that describes the variation of the light angular momentum. The Compton scattering model of a vortex beam is generalized to describe the momentum exchange beyond the well-known photon wave number shift. The illustrated analysis indicates that the light angular momentum may vary due to Compton scattering.

DC and AC Performance of Graphite Films Supercapacitors Prepared by Contact Glow Discharge Electrolysis

In the present work, we fabricate and characterize carbon graphite films by high-voltage cathodic and anodic contact glow discharge electrolysis (CGDE) for supercapacitor applications. Transmission electron microscopy revealed that the carbon films obtained by anodic CGDE, in which a carbon graphite is used as the positive electrode, are in the form of two-dimensional, relatively large lateral size sheets without major fractures or structural distortions. Whereas with the cathodic configuration, tiny and elongated flakes of graphite attached to larger sheets are obtained. We observed negative Raman wavenumber shifts of the G peak and the appearance of the T peak at ca. 1100 cm− 1, which are attributed to thermal-induced strains and structural damages in the graphite crystal lattice, as well as to some C-C sp3 bonds content. In addition to the aforementioned results and optical emission spectroscopy, it is proposed that both formation mechanisms by electrochemical exfoliation and material evaporation occur depending on the used polarization. All-solid-state symmetric supercapacitors using polyvinyl alcohol/H3PO4 as gel electrolyte were fabricated and tested under dc and ac frequencies. We found two different behaviors: at dc and close-to-dc, the material prepared with cathodic CGDE showed close-to-ideal behavior with higher capacitance at different charging/discharging rates, which makes it more suitable for energy storage applications, whereas at higher frequencies ( ⩾ 100 Hz), the material prepared with anodic CGDE performed better for ac filtering applications that has been verified using an inverting integrator circuit.

The Effect of Cesium Chloride on Thermal Properties of Poly (Vinyl Alcohol)

Poly (vinyl alcohol), PVA for short, films doped with different concentrations of cesium chloride(CsCl) (0% , 2% , 4% , 6% , 8% , 10% , 12% , 14% ,16% ) were prepared by solution casting method to study the effect of this salt on thermal properties of PVA by using thermogravimetric analysis (TGA) .It was found that the dopedPVA films with concentrations(14% and 16%) of CsCl aremore thermal stable than PVA while doped PVAfilms with concentrations ( 4% and 6%) of CsCl are less thermal stable than PVA and the dopedPVA films with concentration of ( 2% , 8% , 10% and 12%) are almost as thermal stable as PVA. Fourier transform infrared spectroscopy (FTIR) was also used to investigate complexation between CsCl and PVA and was foundthat the doped PVA films with concentration (2% , 4% , 6% and 8%) of CsClshowno significant shifts in wave numbers of the characteristic bands of PVA while doped PVA films with concentrations (10%, 12% ,14% and 16% ) of CsClshow a significant shifts to a higher values in wave number of stretching vibration of (-OH) comparing to PVA indicating well complexation between CsCl and PVA.

Phosphorous bonding in PCl3:H2O adducts: A matrix isolation infrared and ab initio computational studies

Non-covalent interaction between PCl3 and H2O was studied using matrix isolation infrared spectroscopy and ab initio computations. Computations indicated that the adducts are stabilized through novel P⋯O type phosphorus bonding and conventional PCl⋯H type hydrogen bonding interactions, where the former adduct is the global minimum. Experimentally, the P⋯O phosphorus bonded adduct was identified in N2 matrix, which was evidenced from the shifts in the vibrational wavenumbers of the modes involving PCl3 and H2O sub-molecules. Atoms in Molecules and Natural Bond Orbital analyses have been performed to understand the nature of interactions in the phosphorus and hydrogen bonded adducts. Interestingly, experimental evidence for the formation of higher PCl3H2O adduct was also observed in N2 matrix.