Deuterated Triglycine Sulphate Research Articles

Characterization of Neocarya Macrophylla Seed Oil using Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infra-Red (FT-IR) Techniques

Aim: Modern researches described incorporating gingerbread plum (Neocarya macrophylla) kernel oils into food, cosmetics and pharmaceutical products by exploiting its physicochemical properties.
 Study Design: Experimental and instrumental study was done to determine the general and the saturated fatty acids present in the seed oil and its suitability for industrial applications. This study examined the fatty acids by qualitative determination from hexane extracts of Neocarya macrophylla seed using GC-MS.
 Materials and Methods: Indigenous Neocarya macrophylla seeds obtained from Gingerbread plum tree were collected in the Month of August from Birnin Kebbi, Kebbi State, Nigeria. soxhlet extraction method was used for the oil extraction. The GC-MS analysis was by coupling system of Shimadzu QP2010 series gas chromatography with Shimadzu QP2010 plus mass spectroscopy detector (GCMS). For the FT-IR analysis, software of OMNIC operating system (Version 7.0 Thermo Nicolet) was connected to Fourier Transform Infrared Spectrometer Nicolet 8400S equipped with a detector of deuterated triglycine sulphate (DTGS).
 Conclusion: These results showed the potential of this oil in cosmetic industry.

Temperature Dependence of Ferroelectric Mode of Frequency, Dielectric Constant and Loss Tangent in Deuterated Triglycine Sulphate

Temperature Dependence of Ferroelectric Mode of Frequency, Dielectric Constant and Loss Tangent in Deuterated Triglycine Sulphate

Soft mode and acoustic mode ferroelectric properties of deuterated triglycine sulphate crystal

A mathematical study about deuterated triglycine sulphate (CD2CD2COOD)3D2SO4 crystal by a theoretical model which is extended with two sublattice pseudospin lattice coupled mode model by adding third, fourth and fifth order phonon anharmonic interaction terms as well as external electric field term in the crystal Hamiltonian. Double-time temperature dependent Green’s function is used to derive soft mode frequency, dielectric permittivity, microwave absorption, quality factor, acoustic attenuation, electric conductivity, smooth function, relaxation time, ratio of figure of merits and respective applications in modern technologies. All theoretical results have a good agreement with experimental data.

A neutron diffraction study of the phase transition of fully deuterated triglycine sulphate (ND2CD2COOD)3.D2SO4

AbstractUsing neutron single crystal and powder diffraction, the first thorough investigation of the structure of fully deuterated triglycine sulphate, (ND2CD2COOD)3.D2SO4 is presented, including its evolution with T, through its structural phase transition. This includes new precise structural parameters determined at several key temperatures above and below TC using single crystal diffraction, and for the first time a parametric study has been undertaken over a wide temperature range — from 4 to 500 K in 2 K steps. It was found that fully deuterated TGS shows a structure consistent with hydrogenous TGS and partially deuterated TGS. The evolution of several key hydrogen bond lengths suggests that weakening of the H‐bond network with T is crucial in decoupling the polarising glycine molecules from the other glycines and allowing the long‐range ferroelectric order to break down. A new parameterisation of the phase transition is demonstrated. Contrary to results of physical properties measurements, there is no evidence of a second low temperature phase transition in TGS – no low temperature anomalies were observed in the crystal structure.

ROLE OF ACOUSTIC AND OPTICAL VIBRATION MODES IN FERROELECTRIC CRYSTAL TECHNOLOGIES: (DEUTERATED TRIGLYCINE SULPHATE CRYSTAL)

A modified Green’s function theory with pseudo vibration theory of ferroelectrics has been applied to deuterated triglycine sulphate crystal to predict the applications of the ferroelectric crystal in computing technology.

ROLE OF ACOUSTIC AND OPTICAL VIBRATION MODES IN FERROELECTRIC CRYSTAL TECHNOLOGIES: (DEUTERATED TRIGLYCINE SULPHATE CRYSTAL)

A modified Green’s function theory with pseudo vibration theory of ferroelectrics has been applied to deuterated triglycine sulphate crystal to predict the applications of the ferroelectric crystal in computing technology.

Vapour diffusion growth and characterisation of fully deuterated triglycine sulphate (ND 2CD 2COOD) 3D 2SO 4

A new vial-in-vial vapour diffusion method for growing single crystals of fully deuterated triglycine sulphate (TGS) has been developed. Single crystals of hydrogenous TGS were also grown for comparison purposes. The crystals have been characterised using x-ray diffraction and differential scanning calorimetry. The phase transition temperature was 334.0±0.5 K for fully deuterated TGS compared to 322.3±0.3 K for hydrogenous TGS. These values compare well with the expected T C .

Bias field configuration and twinning in large LADTGS crystals

The internal bias field distribution in large crystals of deuterated triglycine sulphate with an L-alanine impurity (LADTGS) grown on elongated seeds is shown to be inhomogeneous, polar symmetric, and dependent on (010) growth pyramid twinning in the (110)-pyramid zone.

Laboratory set-up for studying ices at the MIR and FIR region

H 2 O, CO and CO 2 ices are condensed on carbonaceous and silicate dust grains in dense interstellar clouds and circumstellar environments. The presence of these ices is inferred by analysing their infrared (IR) spectra. The upcoming Herschel space observatory (HERSCHEL) and ground-based astronomy project (ALMA) will provide new spectral data in the unexplored far infrared (FIR) and sub-millimetre range. In our laboratory we are developing instrumentation to study ices at IR region. One of the key components of our laboratory is a silicon composite bolometer in our IFS. This detector allows us to obtain spectra with a sensitivity much greater than that obtained with a standard deuterated triglycine sulphate (DTGS) detector working at room temperature and under vacuum conditions. We plan to collect mid infrared (MIR) and FIR spectra of simple ices and their mixtures and compare these with observational data. It is also planned to do a systematic laboratory study of the effects that ultraviolet (UV) photolysis and thermal annealing have on the ice band profiles and their structure.

Polarization distribution in DTGS crystals under nonequilibrium thermal conditions

The polarization distribution in crystals of deuterated triglycine sulphate in a constant temperature gradient is investigated on the basis of the dynamic method for studying the pyroelectric effect. It is shown that, under equilibrium thermal conditions, the polarization distribution is uniform except for the surface layer ∼20-μm-thick. The nonuniform polarization distribution in this layer may indicate its multidomain state. In a steady-state temperature gradient, the layer thickens and its domains grow into the sample bulk.

Linear Thermal Expansion of Ferroelectric Deuterated Triglycine Sulphate

Thermal dilatation experiments are performed for partially deuterated triglycine sulphate crystals and the temperature dependence of linear expansion coefficients is studied in the temperature range 77–420 K for the three principal directions. The critical behavior of the crystal due to ferroelectric phase transition is shown to be well described within the first fluctuation correction approach.

Simultaneous measurements of crystal optical characteristics of deuterated triglycine sulphate

AbstractThe birefringence, rotation angle of the optical indicatrix and the gyration along the polar direction are studied in the paraelectric and ferroelectric phases of deuterated triglycine sulphate crystals using the HAUP‐type universal null‐polarimetric technique. The gyration effect in the multidomain ferroelectric phase is found to be negligibly small, in accordance with the symmetry considerations, while the changes in the birefringence and the indicatrix rotation occurring in the course of the phase transition may be described by electrooptical coupling due to the quadratic spontaneous effect.

The Effect of Ageing Process on the Electrogyration of Deuterated Triglycine Sulphate Crystals

The paper reports results of a study of optical activity and ferroelectric properties of rejuvenated and aged deuterated triglycine sulphate crystals. A possibility of monitoring of the ferroelectric crystal ageing process by optical measurements was proved. A linear relation between optical rotatory power p and spontaneous polarization P s was confirmed for aged and rejuvenated deuterated triglycine sulphate crystals.

Decoration of solid state ferroelectric domains by the help of ferroelectric liquid crystals

In this paper we report the experimental data on the visualisation of die domain structure by FLCs in two different crystals: ammonium lithium sulphate (ALS) and deuterated triglycine sulphate (DTGS). In general, for ferroelectric solid crystals (FSC) two different geometries are available for the decoration: polar and nonpolar cuts, i.e. slices normal or parallel to the polar axis. In the experiments with FLC materials we used only polar cuts, i.e. FLC on the polar (010) plane of ALS and DTGS. The samples were prepared as sandwich structures FSC-FLC-electrode-glass substrate. The dynamic switching of the FSC domain-structure is discussed. The generation of a pyroelectric domain structure is also demonstrated.

On the relaxation of macroscopic polarization in DTGS crystals

In the present work the relaxational processes of polarization reversal in deuterated triglycine sulphate crystals (DTGS) were studied under the condition of electric external field commutation. The effects of the electric field magnitude and direction on the switching processes in DTGS were studied at different temperatures. It is shown that the decrease of ε obeys the empirical rule of Kohlrausch ε(t)∼exp(t/τav)α) (τav is the average relaxation time and α is a constant, 0<α≤1) in a wide range of temperature and field. For the DTGS crystal it is valid to use a set of relaxation times. The constant α is function of the external field and temperature.

Temperature Cycling Influence on Pyroelectric Figure of Merit of Triglycine Sulphate Doped with Alanine and Deuterated Triglycine Sulphate Doped with Alanine and Bivalent Platinum Crystals

While heating and cooling in the range 20-60° C, the pyroelectric coefficient, the dielectric permittivity and the specific heat of three samples of triglycine sulphate (TGS) family have been measured. These samples were TGS doped with alanine (ATGS), deuterated TGS doped with alanine (ADTGS), and deuterated TGS doped with alanine and bivalent platinum (ADTGS:Pt). Using these data, the thermal hysteresis of the pyroelectric figure of merit F v of these three crystals has been studied in this temperature range. The highest value of F v was obtained for the ADTGS:Pt crystal while the widest temperature range in which F v can be considered constant was obtained for the ADTGS crystal.

Thermal emission spectrometer experiment: Mars Observer mission

Thermal infrared spectral measurements will be made of the surface and atmosphere of Mars by the thermal emission spectrometer (TES) on board Mars Observer. By using these observations the composition of the surface rocks, minerals, and condensates will be determined and mapped. In addition, the composition and distribution of atmospheric dust and condensate clouds, together with temperature profiles of the CO2 atmosphere, will be determined. Broadband solar reflectance and thermal emittance measurements will also be made to determine the energy balance in the polar regions and to map the thermophysical properties of the surface. The specific science objectives of this investigation are to determine (1) the composition and distribution of surface materials, (2) the composition, particle size, and spatial and temporal distribution of suspended dust, (3) the location, temperature, height, and water abundance of H2O clouds, (4) the composition, seasonal behavior, total energy balance, and physical properties of the polar caps, and (5) the particle size distribution of rocks and fines on the surface. The instrument consists of three subsections: a Michelson interferometer, a solar reflectance sensor, and a broadband radiance sensor. The spectrometer covers the wavelength range from 6 to 50 μm (∼1600–200 cm−1) with nominal 5 and 10 cm−1 spectral resolution. The solar reflectance band extends from 0.3 to 2.7 μm; the broadband radiance channel extends from 5.5 to 100 μm. There are six 8.3‐mrad fields of view for each sensor arranged in a 3 × 2 array, each with 3‐km resolution at the nadir. Uncooled deuterated triglycine sulphate (DTGS) pyroelectic detectors provide a signal‐to‐noise ratio (SNR) of over 500 at 10 μm for daytime spectral observations at a surface temperature of 270 K. The SNR of the albedo and thermal bolometers will be approximately 2000 at the peak signal levels expected. The instrument is 23.6 × 35.5 × 40.0 cm, with a mass of 14.4 kg and an average power consumption of 14.5 W. The approach will be to measure the spectral properties of thermal energy emitted from the surface and atmosphere. Emission phase angle studies and day‐night observations will be used to separate the spectral character of the surface and atmosphere. The distinctive thermal infrared spectral features present in minerals, rocks, and condensates will be used to determine the mineralogic and petrologic character of the surface and to identify and study aerosols and volatiles in the atmosphere.

Enhanced Growth of Nonpolar {001} Growth Sectors of Deuterated Triglycine Sulphate Doped with L‐Alanine (LADTGS)

AbstractThe crystals of deuterated triglycine sulphate substituted with L‐alanine (LADTGS) were grown from nonpolar {001} growth sectors by four different methods.35 mol% of L‐alanine (LA) in the growth solution give a stable unipolarity of the crystals. A distribution of LA was measured by the electrical switching method using “hysteresis current” loops. A defect structure was observed in a microscope on the etched surface of crystals. Most uniform crystals have been obtained using an isothermal method without stirring of the growth solutions.

Audio and subaudio dielectric dispersion in Deuterated Triglycine Sulphate

Abstract Experimental values are reported for the complex dielectric permittivity, ϵ (ω), of single crystal Deuterated Triglycine Sulphate (DTGS) at temperatures on both sides of the ferroelectric Curie temperature Tc, covering the audio and subaudio frequency range, (102 to 105 and 10−4 to 1 Hz). In the audio frequency range, in contrast with the strong typical ferroelectric dispersion in the GHz region, the dielectric losses and the real part of the susceptibility X (ω) = ϵ (ω) - ϵ∞ follow the empirical relation X″ (ω) ∼ ωn-1 which gives a frequency independient ratio, according to the Jonscher universal law for the dielectric response X″/X′ = cot (nII/2). However, in the subaudio frequency region we find that the dielectric loss fits the empirical relation X″ (ω) ∼ ω when ω → 0. The experimental results are discussed.

The preparation and performance of reticulated targets for the pyroelectric vidicon

Abstract The spatial resolution of the pyroelectric vidicon may be significantly improved by reticulation of the pyroelectric target. This paper describes the development of techniques and structures for the preparation of high quality reticulated vidicon targets in deuterated triglycine sulphate (DTGS). The dimensions of the reticulated target structures were selected using the results of a theoretical analysis. Reticulated targets were prepared by low energy ion-beam milling of thin targets of DTGS. The ion-beam etching characteristics of this material are described and the selection of masking materials, support layers and the signal electrode are discussed. Large numbers of targets were scanned in vidicon tubes so that differences in imaging performance and cosmetic appearance could be correlated to changes made to the target configuration and etching process. From this study an optimum target preparation and processing route was developed which provided significant improvement in resolution over tube...