Spectrographic Techniques Research Articles

Assessment of freeze damage in tuber starch with electrical impedance spectroscopy and thermodynamic, rheological, spectrographic techniques

In this study, we aimed to use electrical impedance spectroscopy (EIS) to assess the freeze-damage level of starches from potato tubers treated with multiple freezing-thawing (FT) cycles. The results showed that the relationship between the physicochemical properties of starches and the impedance characteristics of starch paste is temperature-dependent. As the temperature rises to 70–90 °C, the impedance modules show a significant correlation with the amylose and mineral contents, gelatinization and pasting properties, short-range ordered structure, relative crystallinity, and damage level within the range of 10–1 MHz (p < 0.01). This could be because FT leads to a reduction in amylose and ion content. Compared to a high level of freeze-damaged starch (FDS), a low level of FDS has less amylopectin and more amylose. Additionally, the ions could be typically evenly distributed throughout the unbranched linear amylose structure in starch paste. At the peak gelatinization temperature, the starch paste made from a low level of FDS exhibits a weakened network structure, allowing more unbound water for ion movement and enhancing electric conduction. In conclusion, EIS can predict the damage level and properties of FDS, which can benefit the frozen starchy food industry.

Origin of Blue-Water Jadeite Jades from Myanmar and Guatemala: Differentiation by Non-Destructive Spectroscopic Techniques

Identifying the origin of jadeite jades has become increasingly important from both mineral resource and metamorphic geology perspectives. In this study, we differentiate Myanmar gem-quality blue-water jadeite jades from their Guatemala counterparts via integrating various non-destructive spectrographic techniques, including X-ray fluorescence (XRF), Ultraviolet-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Our results show that the Myanmar blue-water jadeite jades are structurally homogenous with very few impurities, while their Guatemala counterparts commonly have a yellowish margin with scattered white albite and disseminated greenish inclusions of omphacite and (minor) aegirine-augite. Geochemically, the UV absorption spectral data indicate that the Guatemala samples have higher total Fe and Fe2+ contents, but lower Fe3+ content than the Myanmar samples. The Guatemala samples also have higher omphacite content (lower molar Na/(Na+Ca) ratio, as reflected by the lower IR absorption peak wavenumber) and higher heterogeneity (as reflected by the ~680 cm−1 Raman peak shift difference) than that from Myanmar. Major differences are also discovered in the blue series (Myanmar: 0–0.7 cm−1; Guatemala: 1.7–3.2 cm−1) and blue-green series (Myanmar: 6.9 cm−1; Guatemala 13.7 cm−1) of the Raman peak shift difference, which altogether can provide a novel, nondestructive method for distinguishing blue-water jadeite jades from different origins.

Synthesis of new 1,4-disubstituted 1,2,3-triazoles using the CuAAC reaction and determination of their antioxidant activities.

This study describes the synthesis and antioxidant activity of new 1,4-disubstituted 1,2,3-triazoles. These compounds were generated semi-synthetically using the Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC) reaction between ethyl 2-azidoacetate and terminal acetylenes derived from the natural products carvacrol, eugenol, isovanillin, thymol and vanillin. The products were obtained at 50 to 80% yield and characterised through several spectrographic techniques. Antioxidant activity was assayed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The products exhibited moderate antioxidant activity, with ethyl 2-(4-((4-formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl) acetate showing the highest antioxidant capacity (EC50 = 75.5 µg/mL) among the generated 1,4-disubstituted 1,2,3-triazoles. In conclusion, the generation of these compounds opens new possibilities for the development of new antioxidant agents.

Color Spectrographic Analysis of Respiratory Sounds: A Promising Technology for Respiratory Monitoring

Background: The need for reliable respiratory monitoring has increased in recent years with the frequent use of opioids for perioperative pain management as well as a high prevalence of patients suffering from respiratory comorbidities. Objective: Motivated by the success of acoustical color spectrographic techniques in other knowledge domains, we sought to build proof-of-concept systems for the computer-based color spectrographic analysis of respiratory sounds, recorded from various sites. Methods: We used a USB miniature electret microphone and a Windows-based color spectrographic analysis package to obtain color spectrograms for breath sound recordings from the neck, from an oxygen mask, from the ear canal, and from a leak-free microphone pneumatically connected to the cuff of a laryngeal mask airway. Results: Potentially useful color spectrographic displays were obtained from all four recording sites, although the spectrograms obtained varied in their characteristics. It was also found that obtaining high-quality color spectrograms requires attention to a number of technical details. Conclusion: Color spectrographic analysis of respiratory sounds is a promising future technology for respiratory monitoring.

Expression, purification, and characterization of N-terminal His-tagged proteins with mutations in zinc finger 3 of zinc finger protein ZNF191(243–368)

Zinc finger protein ZNF191(243–368), the zinc finger region of ZNF191, is potentially associated with cell proliferation in hepatocellular carninoma. A His-tag expression system was used to express and purify proteins with mutations in the zinc finger 3 of ZNF191(243–368) for analysis of protein properties, structure, and functions. The purification of the His-tag fusion proteins was simpler and faster than that of the ZNF191(243–368) inclusion bodies. The properties and structures of the His-tag fusion mutant proteins were investigated using spectrographic techniques and DNA hydrolysis experiment. The His6-tag system could be used to express ZNF191(243–368). The presence of the His6-tag at the N-terminus of ZNF191(243–368) did not evidently affect its properties and structure. However, the site-directed mutations in zinc finger 3 affected the structure of the protein. The DNA hydrolase activity of His6-ZF-F3/H4 suggested that four histidines in zinc finger 3 might form a structure similar to that of the active center in a hydrolase. This work reports that continuous histidines need to form a certain structure for specific functions, and provides new insights into the design of an artificial nuclease.

Production of Karanja Methyl Ester from Crude Karanja Oil Using Meretrix Lyrata Synthesised Active CaO Catalyst

Active calcium oxide catalyst was synthesised from Meretrix Lyrata (M.Lyrata) following calcination-hydration-dehydration technique. The catalytic feasibility of synthesised CaO was investigated in the production of Karanja methyl ester (KME) from crude Karanja oil (CKO). KME was synthesised through esterification using followed by transesterification utilising CaO in a two-step reaction process of CKO and methanol. The M.Lyrata shells were calcined at 900 ℃ and the catalyst samples were characterised using FTIR, SEM, PSA, and BET-BJH spectrographic techniques. A maximum fatty acid methyl ester (FAME) conversion of 97.3 % was obtained at optimum reaction conditions including methanol-to-oil ratio of 12:1, catalyst concentration of 2 wt.%, reaction temperature of 58 ℃ and reaction time of 2 hrs. In a comparative study with commercial CaO, M.Lyrata showed a higher catalytic activity. The catalyst reusability experiments ascertaining reusability of CaO up to four reuse cycles had shown good efficiency. The economic comparative study confirms that CaO derived from M.Lyrata can be used as an alternative and feasible catalyst for biodiesel production. The KME fuel properties complied to EN-14214 biodiesel fuel standards.

Mid-infrared and near-infrared spectroscopy for rapid detection of Gardeniae Fructus by a liquid-liquid extraction process

Gardeniae Fructus is widely used in the pharmaceutical industry, and many studies have confirmed its medical and economic value. In this study, samples collected from different liquid-liquid extraction batches of Gardeniae Fructus were detected by mid-infrared (MIR) and near-infrared (NIR) spectroscopy. Seven analytes, neochlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), chlorogenic acid (3-CQA), geniposidic acid (GEA), deacetyl-asperulosidic acid methyl ester (DAAME), genipin-gentiobioside (GGB), and gardenoside (GA), were chosen as quality property indexes of Gardeniae Fructus. The two kinds of spectra were each used to build models by single partial least squares (PLS). Additionally, both spectral data were combined and modeled by multiblock PLS. For single spectroscopy modeling results, NIR had a better prediction for high-concentration analytes (3-CQA, DAAME, GGB, and GA) whereas MIR performed better for low-concentration analytes (5-CQA, 4-CQA, and GEA). The multiblock methodology was found to be better compared to single spectroscopy models for all seven analytes. Specifically, the coefficients of determination (R2) of the NIR, MIR, and multiblock PLS calibration models of all seven components were higher than 0.95. Relative standard errors of prediction (RSEP) were all less than 7%, except for models of GGB, which were 10.36%, 13.24%, and 8.15% for the NIR-PLS, MIR-PLS, and multiblock models, respectively. These results indicate that MIR and NIR spectrographic techniques could provide a new choice for quality control in industrial production of Gardeniae Fructus.

Active Razor Shell CaO Catalyst Synthesis for Jatropha Methyl Ester Production via Optimized Two-Step Transesterification

Calcium based catalysts have been studied as promising heterogeneous catalysts for production of methyl esters via transesterification; however a few were explored on catalyst synthesis with high surface area, less particle size, and Ca leaching analysis. In this work, an active Razor shell CaO with crystalline size of 87.2 nm, SBET of 92.63 m2/g, pore diameters of 37.311 nm, and pore volume of 0.613 cc/g was synthesized by a green technique “calcination-hydro aeration-dehydration.” Spectrographic techniques TGA/DTA, FTIR, SEM, XRD, BET&amp;BJH, and PSA were employed for characterization and surface morphology of CaO. Two-step transesterification of Jatropha curcas oil was performed to evaluate CaO catalytic activity. A five-factor-five-level, two-block, half factorial, central composite design based response surface method was employed for experimental analysis and optimization of Jatropha methyl ester (JME) yield. The regression model adequacy ascertained thru coefficient of determination (R2: 95.81%). A JME yield of 98.80% was noted at C (3.10 wt.%), M (54.24 mol./mol.%), T (127.87 min), H (51.31°C), and R (612 rpm). The amount of Ca leached to JME during 1st and 4th reuse cycles was 1.43 ppm ± 0.11 and 4.25 ppm ± 0.21, respectively. Higher leaching of Ca, 6.67 ppm ± 1.09, was found from the 5th reuse cycle due to higher dispersion of Ca2+; consequently JME yield reduces to 76.40%. The JME fuel properties were studied according to biodiesel standards EN 14214 and comply to use as green biodiesel.

Active Heterogeneous CaO Catalyst Synthesis fromAnadara granosa(Kerang) Seashells for Jatropha Biodiesel Production

Heterogeneous catalysts are often used at large to produce biodiesel from non-edible vegetable crude oils such as Jatropha curcas oil (JCO). In this study, an active heterogeneous CaO catalyst was synthesized from a tropical biodiversity seashells Anadara granosa (A.granosa). The catalytic efficiency of A.granosa CaO was investigated in transesterification of JCO as biodiesel. The A.granosa CaO catalyst was synthesized using 'Calcination - hydration - dehydration' protocol. The spectral characterization of the catalyst were investigated by employing FT-IR, SEM, BET and BJH spectrographic techniques. The experimental design was executed with four reaction parameters that include catalyst concentration (CC), methanol ratio (MR), transesterification time (TT) and reaction temperature (RT). The JCO transesterification reactions as well as impact of reaction parameters on the Jatropha biodiesel yield (JBY) were analyzed. The sufficiency of the experimental results conformed through sequential validation tests, as a result, an average of 96.2% JMY was noted at optimal parametric conditions, CC of 3wt. %, TT of 120 min, MR of 5 mol. and RT of 60C at a constant agitation speed of 300rpm. An average JMY of 87.6% was resulted from the A.granosa CaO catalyst during their recycling and reuse studies up to third reuse cycle

Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

Effect of His-Tag on Expression, Purification, and Structure of Zinc Finger Protein, ZNF191(243-368).

Zinc finger proteins are associated with hereditary diseases and cancers. To obtain an adequate amount of zinc finger proteins for studying their properties, structure, and functions, many protein expression systems are used. ZNF191(243-368) is a zinc finger protein and can be fused with His-tag to generate fusion proteins such as His6-ZNF191(243-368) and ZNF191(243-368)-His8. The purification of His-tag protein using Ni-NTA resin can overcome the difficulty of ZNF191(243-368) separation caused by inclusion body formation. The influences of His-tag on ZNF191(243-368) properties and structure were investigated using spectrographic techniques and hydrolase experiment. Our findings suggest that insertion of a His-tag at the N-terminal or C-terminal end of ZNF191(243-368) has different effects on the protein. Therefore, an expression system should be considered based on the properties and structure of the protein. Furthermore, the hydrolase activity of ZNF191(243-368)-His8 has provided new insights into the design of biological functional molecules.

Biodiesel Production from Crude Jatropha Oil using a Highly Active Heterogeneous Nanocatalyst by Optimizing Transesterification Reaction Parameters

Various heterogeneous catalysts are often used to produce biodiesel from non-edible crude oils. In this study a highly active heterogeneous calcium oxide (CaO) nanocatalyst with a diameter and surface area of 66 ± 3 nm and 90.61 m2/g, respectively, was synthesized from Polymedosa erosa (P. erosa) seashells through a calcination–hydration–dehydration technique. The nano-CaO catalysis impact was investigated in a two-step transesterification of triglycerides from crude Jatropha oil as a biodiesel along with other reaction parameters such as catalyst ratio, reaction time, and methanol to oil ratio. Fourier transform infrared spectroscopy, transmission electron microscope, X-ray diffraction, and Brunauer–Emmett–Teller spectrographic techniques were utilized to evaluate the CaO nanocatalyst spectral and structural characteristics. The effect of the transesterification parameters on reaction kinetics and Jatropha biodiesel (JB) yield were analyzed by employing a three-factor-five-level response surface methodol...

Organic Sodium Based Flow Batteries Utilizing Transition Metal and Metal Free Complexes

The utilization of redox flow batteries (RFBs) for large scale energy storage has acquired much interest due to the large cycle life and flexibility in system via the decoupling of energy and power. Although RFBs show increasing promise, they suffer from low energy density due to the utilization of aqueous electrolytes which are limited in voltage due to hydrogen and oxygen evolution. A new hybrid sodium based flow battery has been developed which utilizes a molten sodium alloy anode separated from the flowing catholyte by a solid beta”-alumina membrane. An organic catholyte consisting of either transition metal complexes which can be cycled through several oxidation states or metal free organic complexes has been investigated in conjunction with the molten anode. Spectrographic techniques such as UV-Vis and IR absorption will be used to analyze the transitions at different states of charge and at various cycles to determine both the change in valence of the active species as well as the shift of chemical bonds which may affect the reversibility of the systems.

An equivalence between typical spectrographic data analysis and the formulations for time series analysis

We have demonstrated the equivalence of two formulations for data processing, which usually are studied separately and independently. Habitually, for time series analysis, like signals processed in communications, electronics, control sciences, etc., mathematical tools based on autocorrelations, cross-correlations or convolutions, etc., are applied. Another sort of formulations is applied for analysis in spectrographic techniques, where the data is usually processed with statistical procedures based on the least square method. The equivalence demonstrated between both methodologies opens new possibilities in time series analysis, in order to find predetermined structures in the acquired data. Also, all of the mathematical criteria often used in spectroscopic analysis like the limit of detection, or the determination limit, could be applied in methods for analysis of data depending on time.

Taphonomy Or Paint Recipe: In situ portable x-ray fluorescence analysis of two anthropomorphic motifs from the Woronora Plateau, New South Wales

Portable spectrographic techniques have desirable attributes for archaeological investigations because they can be applied in the field non-invasively and non-destructively. With the increasing ubiquity of portable spectrographic techniques in Australia it is timely that the complexities of field-based analyses are discussed. A review of portable x-ray fluorescence (PXRF), including the limitations of the technique, and discussion of the complex physical interactions encapsulated by the resulting elemental data, provide a firm basis for interpreting the analysis of a rock art panel on the Woronora Plateau, New South Wales. PXRF data supports the results of previous (laboratory-based) pigment characterisations, that a locally sourced, composite clay-based paint was used to produce rock art. Results highlight the requirement for specific knowledge and expertise, not only in relation to the technique, but also the rock art under investigation and, critically, its taphonomic context. Ultimately this case study demonstrates that portable spectrometry should be considered an addition to the existing repertoire of archaeometric techniques applicable to the study of rock art, rather than as a replacement for laboratory analyses.

COLOR SPECTROGRAPHIC PHONOCARDIOGRAPHY FOR THE DETECTION AND CHARACTERIZATION OF PEDIATRIC HEART MURMURS: A CASE SERIES

Although auscultation of the heart remains central in the detection of abnormal heart sounds and murmurs that are frequently indicative of serious cardiac pathology, the application of electronic methods to this end remains rarely used in daily clinical practice. In this report we provide a series of examples showing how the phonocardiogram can be analyzed quantitatively using color spectrographic techniques and discuss how such methods may be of future value for noninvasive cardiac monitoring. Using a sound recording system, we recorded the heart sounds and data acquisition using the program Gold Wave ( http://www.goldwave.com ) to collect data from a high-speed USB interface. Sample color spectrogram analysis of the obtained signals was performed using custom software written in MATLAB. Data was collected from a number of infants and adults with cardiac structural disease as well as from some normal individuals. Our data is presented as a series of 13 cases. We expect the application of spectrographic techniques to phonocardiography to grow substantially as ongoing research and clinical experience demonstrates its utility in various settings. Our evaluation of a simple, low-cost phonocardiographic recording and analysis system to assist in determining the characteristic features of heart murmurs shows promise in helping distinguish normal heart sounds, innocent systolic murmurs and pathological murmurs in children. It expected to be useful in other clinical settings as well.

A color spectrographic phonocardiography (CSP) applied to the detection and characterization of heart murmurs: preliminary results

BackgroundAlthough cardiac auscultation remains important to detect abnormal sounds and murmurs indicative of cardiac pathology, the application of electronic methods remains seldom used in everyday clinical practice. In this report we provide preliminary data showing how the phonocardiogram can be analyzed using color spectrographic techniques and discuss how such information may be of future value for noninvasive cardiac monitoring.MethodsWe digitally recorded the phonocardiogram using a high-speed USB interface and the program Gold Wave http://www.goldwave.com in 55 infants and adults with cardiac structural disease as well as from normal individuals and individuals with innocent murmurs. Color spectrographic analysis of the signal was performed using Spectrogram (Version 16) as a well as custom MATLAB code.ResultsOur preliminary data is presented as a series of seven cases.ConclusionsWe expect the application of spectrographic techniques to phonocardiography to grow substantially as ongoing research demonstrates its utility in various clinical settings. Our evaluation of a simple, low-cost phonocardiographic recording and analysis system to assist in determining the characteristic features of heart murmurs shows promise in helping distinguish innocent systolic murmurs from pathological murmurs in children and is expected to useful in other clinical settings as well.

Speaker identification: Effects of noise, telephone bandwidth, and word count on accuracy.

It is of great interest by the legal system to identify individuals by their voice. Controversy in this area has continued for nearly five decades with states divided with regard to the merits of voice identification. The American Board of Recorded Evidence [ABRE (1999)] has established standards for the determination of identification or elimination of speakers. Digital spectrographic techniques, including formant tracking and finer descriptive measures of speech, are dramatic improvements and allow a test of the ABRE standards using improved technology embodying similar principles set forth in an aural and spectrographic method. Ten speakers recorded synthetic sentences at two different times. Words were distorted by mixing with noise or by telephone bandwidth reduction. All possible speaker pairs of “elimination” were presented to qualified listeners as well as equal probability of “identification.” For the comparison, subjects were presented spectrograms, formant tracks, fundamental frequency, and the ability to listen to single words. Confidence ratings and determinations (elimination or identification) for each comparison word were made with the addition of added words(<20). The results will be discussed with regard to correct classification based upon the number of words required and the reduction of correct classification based upon the distorted conditions.

Estudo eletropalatográfico das seqüências /s s/ e /s S/ em português brasileiro

This paper analyses coarticulation process that occurs when onevoiceless alveolar fricative follows another alveolar voiceless fricativewith a word boundary between them and when one alveolar voicelessfricative follows a voiceless post-alveolar fricative with also a wordboundary between them. In order to do that, we utilized theelectropalatographic and spectrographic techniques. The resultsindicate that, in the context /s # s/, the sequence had the same acousticand electropalatographic characteristics as the voiceless alveolarfricative in initial syllable position, but the sequence /s # S/ presenteddifferent characteristics from both the voiceless alveolar fricativeand the voiceless post-alveolar fricatives.

Age-related psychomotor slowing as an important component of verbal fluency

Generalized psychomotor slowing is a characteristic of normal aging, and there is evidence suggesting that this feature is also central in dementia. The present article aims to evaluate the importance of psychomotor slowing as a factor underlying changes in the performance of verbal fluency tasks in normal and pathological aging. In study 1 reading and handwriting speed were used to predict performance on written and oral verbal fluency tasks (VFTs) in healthy elderly subjects (n = 20) and in patients of the Alzheimer type disease (n = 20). In study 2, spectrographic techniques were used to obtain reaction times, average of voice intensity and duration of single word production in young individuals (n = 20), healthy elderly subjects (n = 20), and in patients of the Alzheimer type disease (n = 7). Additionally, duration of single word production were also obtained. The results suggest that age-related psychomotor decline in word production speed is an important determinant of VFT.