Ultraviolet Spectral Data Research Articles

Ultraviolet visible spectral water chemical oxygen demand detection method based on two deep neural network model

Water resources are precious resources around the world, but pollution is becoming increasingly severe. While the degree of damage to water caused by organic pollutants is reflected by chemical oxygen demand, which is also an important indicator for hydrological monitoring. Therefore, accurate measurement of chemical oxygen demand is necessary. The rapid development of water quality detection by ultraviolet visible spectrum analysis as an efficient, convenient, and pollution-free new water quality detection method has been achieved. When we were processing ultraviolet visible spectral absorbance data, various environmental factors can affect the chemical oxygen demand light absorption value, thus affecting the accuracy of detection. So there are some goals, such as more comprehensively extracting the feature wavelength and reducing the interference to achieve better detection results. It is expected that the model can be applied to a portable water quality detection device. It is necessary to consider detection time, reduce model training parameters, and improve detection speed. Therefore, this article proposes Competitive Adaptive Weighted Sampling-Convolutional Neural Network-Long Short-Term Memory and Competitive Adaptive Weighted Sampling-Convolutional Long Short-Term Memory models for detecting chemical oxygen demand in water. To verify the effectiveness of the proposed model, the model was trained on the experimental dataset and the detection results of all models involved in the article were compared. It can be confirmed that the application of these two proposed algorithms results in less detection time and higher accuracy in concentration detection.

ISOLATION, IDENTIFICATION AND BIOASSAY OF FLAVONOIDS FROM Bouea macrophylla GRIFF.

Bouea macrophylla Griff., a species belonging to the Anacardiaceae family is a flowering plant native to Southeast Asia and also known as kundang, kundang daun besar, and setar in Malaysia. The fruit can be eaten raw or as a pickle, while the young leaves can be consumed as salads. It has been claimed to be able to accelerate wound healing, prevent cancer, reduce the risk of stroke, and be good for blood circulation. The previous study on the plant from the same genus, known as B. oppositofolia has shown the presence of various. The present study was designed to isolate and elucidate flavonoids from this plant. The twig extract of kundang was purified by using several chromatographic techniques including Vacuum Liquid Chromatography (VLC), Column Chromatography (CC), and preparative-Thin Layer Chromatography (pTLC). The structures of isolated compounds were characterized by using spectroscopic methods including Nuclear Magnetic Resonance (NMR), infrared (IR), and ultraviolet (UV) spectral data, as well as comparison with the data reported in the literature. Five flavonoids were isolated and purified from the twigs of B. macrophylla which includes one flavanonol known as garbanzol; one flavonol which is resokaempferol; one flavandiol characterized as catechin; and two flavandiol known as mollisacacidin and guibourtacacidin. The results of the glucose uptake experiment indicated that the extract and compounds tested affected the glucose uptake rate of the insulin-resistant C2C12 cell line as compared to the standard. This is the first report describing the elucidation of the stated compounds from B. macrophylla as well as its glucose uptake study.

UV spectroscopy and HPLC combined with chemometrics for rapid discrimination and quantification of Curcumae Rhizoma from three botanical origins

Curcumae Rhizoma (Ezhu in Chinese) is a multi-origin herbal medicine with excellent clinical efficacy. For fast discrimination and quantification analysis of Ezhu from three botanical origins (Curcuma kwangsiensis, Curcuma phaeocaulis, and Curcuma wenyujin), ultra-violet (UV) spectroscopy and high performance liquid chromatography (HPLC) combined with chemometric tools were employed in this study. Firstly, the analysis method for the simultaneous determination of eleven compounds in Ezhu was developed by HPLC, and the UV spectra of thirty-eight batches of Ezhu were acquired. Then, principal component analysis (PCA), an unsupervised pattern recognition method, was applied on the HPLC and UV spectral data. PCA did not show a clear separation between C. phaeocaulis and C. wenyujin samples with HPLC data. By contrast, the supervised techniques, decision tree (DT) and linear discriminant analysis (LDA), achieved the complete discrimination for the three species of Ezhu with 100 % correct classification rate (CCR), showing excellent performance. Based on UV spectral data, PCA presented good performance for discriminating the three species of Ezhu. LDA, support vector machine (SVM) and k-nearest neighbors (KNN) models provided 96.3 % CCR for the calibration set and 100 % CCR for the validation set. Moreover, the partial least squares (PLS) and back propagation-artificial neural network (BP-ANN) quantitative models established on UV spectral data were satisfactory in predicting the contents of zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane. The residual predictive deviation (RPD) for zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane of PLS models were 3.169, 1.502 and 1.735, and that of BP-ANN models were 3.467, 2.481 and 2.370, respectively. The present work proposed a rapid and reliable method for the discrimination of Ezhu from three botanical origins and the prediction of zederone, curdione and 3,5-dihydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane contents in Ezhu, which will help a lot in the quality control of Ezhu and other multi-origin herbal medicines.

Inactive Cu2O Cubes Become Highly Photocatalytically Active with Ag2S Deposition.

Previously, Cu2O cubes have been shown to remain photocatalytically inert toward methyl orange degradation even after surface decoration with ZnO, ZnS, CdS, and Ag3PO4 nanostructures. Surprisingly, when Ag2S nanoparticles are lightly deposited on Cu2O cubes as seen through scanning electron microscopy (SEM) images, the heterostructures become highly photocatalytically active. X-ray diffraction (XRD) patterns show mainly Cu2O diffraction peaks due to lightly deposited Ag2S, but Ag2S peaks can emerge with increased Ag2S deposition. X-ray photoelectron spectroscopy (XPS) analysis also supports Ag2S formation on Cu2O crystals. The Ag2S-deposited Cu2O octahedra and rhombic dodecahedra show the expected activity enhancement. Electron paramagnetic resonance (EPR) measurements, as well as electron, hole, and radical scavenger tests, all confirmed the emergence of photocatalytic activity from the Ag2S-Cu2O cubes. Photoluminescence lifetimes are shortened after Ag2S deposition. Electrochemical impedance measurements revealed a large decrease in charge transfer resistance for Cu2O cubes after the Ag2S deposition. Unexpectedly, the separately synthesized Ag2S particles are also photocatalytically inactive. No specific lattice planes of Ag2S are formed directly over the {100} face of Cu2O. Diffuse reflectance and ultraviolet photoelectron spectral data were used to construct band diagrams of different Cu2O crystals and Ag2S nanoparticles. A Z-scheme charge transfer mechanism may be involved at the heterojunction interface to promote charge carrier separation. However, to explain the sudden appearance of photocatalytic activity from the Ag2S-deposited Cu2O cubes, a large change in the {100} surface band bending after Ag2S deposition should be used. This work illustrates that an unusual photocatalytic outcome is possible to semiconductor heterojunctions, where two photocatalytically inert components can become highly active when joined together.

Synthesis, Characterization, Antimicrobial and DNA Binding Studies of a Tetradentate N2O2 Amino Acid Schiff Base and Its Coordination Compounds

Aminoethanoic acid undergoes condensation with 1,4-benzenedicarboxaldehyde to form an O, N, N, O donor Schiff base, N,N'-di(carboxymethylene) terephthalaldehyde, Ligand L. Coordination compounds of this Schiff base using Ni (II), Cu (II), VO (IV) and Co (II) were then obtained in-situ. The Schiff base and the complexes were evaluated for their antimicrobial and DNA binding abilities. Molecular docking studies of the ligand and synthesized compounds were also carried out. Evidence for the formation of the Schiff base coordination compounds and the coordinating atoms was obtained from 1H NMR, infrared and ultraviolet spectral data, EDX, EDTA complexometric titration and magnetic susceptibility measurement. The results obtained are consistent with octahedral geometry for Ni (II) complex, the metal ion coordinating to one molecule of Ligand L and with additional coordination with two oxygen atoms of two molecules of the solvent. A square-planar geometry was suggested for both Co (II), and Cu (II) complexes and a five-coordinate, square pyramidal geometry for the VO (IV) complex. The results further indicated that the carboxylic acid of Ligand L was not deprotonated both in the free base and also the complexes. In addition, the results showed that Compound 2 elicited the best antimicrobial activity potential. Generally, the compounds exhibited considerable good affinity to CT-DNA.

SYNTHESIS AND EVALUATION OF TASTE-MASKED IONIC LIQUID SALTS OF LORATADINE

Objective: To synthesize and evaluate taste-masked ionic liquid (IL) salts of loratadine.
 Methods: In the present work, pharmaceutically active IL salts of loratadine using selected counter-ions were synthesized. The synthesized IL salts were characterized using melting point, Ultraviolet (UV) spectroscopy, Fourier Transform Infra-Red (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), and X-ray Diffraction (XRD). These salts were also evaluated for solubility, dissolution, and palatability studies.
 Results: All synthesized IL salts of loratadine exhibited melting points below 100 °C. UV spectral data and FTIR data confirmed the formation of new salt forms with selected counter-ions. The absence of sharp melting point peaks during DSC studies revealed the amorphous nature of new salt forms. During XRD studies, loratadine-indomethacin IL salt yields completely amorphous compound while the intensity of characteristic peaks of loratadine was found to be reduced with other counter-ions. Solubility studies revealed that the solubility of loratadine is reduced from 35.85 mg/ml to 3.63 mg/ml, 15.39 mg/ml, 5.31 mg/ml, and 3.71 mg/ml in case of IL-1, IL-2, IL-3, and IL-4, respectively. Dissolution studies further confirmed this finding. Except for oleate, all the IL salts were found to be palatable by subjects with the score ranging from 2.5 to 2.8, which is the standard range for palatability.
 Conclusion: Results obtained in the present work indicated that IL salts of loratadine can be synthesized successfully using selected counter-ions. This approach can be used to mask the bitter taste of pure loratadine and thus can be used for the development of drug products intended for children.

FTIR and UV spectra for the prediction of triterpene acids in Macrohyporia cocos

The aim of this study was to exploit the potential of rapid and simple spectroscopic techniques combined with partial least squares (PLS) regression using for the content prediction of five triterpene acids in Macrohyporia cocos. Ultraviolet of 80% ethanol extract (UV1), ultraviolet of ethyl acetate extract (UV2), Fourier transform mid-infrared (FT-MIR) and Fourier transform near-infrared (FT-NIR) spectra of samples were collected. The data processing methods of spectral pretreatment, feature extraction and data fusion were adopted to improve prediction performance. The results showed that: (1) UV1, UV2 and FT-MIR did work for content prediction except FT-NIR. (2) Variable importance for the projection (VIP) outperformed interval PLS in feature extraction for the prediction of triterpene acids of M. cocos. Data fusion had no distinct advantage compared with single set analysis (3) Both UV1 and FT-MIR could achieve the prediction of poricoic acid A, and UV1 outperformed FT-MIR. (4) The UV1 subjected by second-order derivative pretreatment and VIP extraction was satisfactory for predicting poricoic acid A and dehydrotumulosic acid. The UV2 preprocessed by first-order derivative could achieve approximate prediction of dehydrotrametenolic acid. This study demonstrated that ultraviolet and mid-infrared spectral data were promising techniques for the rapid prediction of poricoic acid A (UV1 and FT-MIR), dehydrotumulosic acid (UV1) and dehydrotrametenolic acid (UV2) in M. cocos, and ultraviolet spectroscopy was superior to infrared one.

Long-term Variations of Venus’s 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope

Abstract An unknown absorber near the cloud-top level of Venus generates a broad absorption feature from the ultraviolet (UV) to visible, peaking around 360 nm, and therefore plays a critical role in the solar energy absorption. We present a quantitative study of the variability of the cloud albedo at 365 nm and its impact on Venus’s solar heating rates based on an analysis of Venus Express and Akatsuki UV images and Hubble Space Telescope and MESSENGER UV spectral data; in this analysis, the calibration correction factor of the UV images of Venus Express (Venus Monitoring Camera) is updated relative to the Hubble and MESSENGER albedo measurements. Our results indicate that the 365 nm albedo varied by a factor of 2 from 2006 to 2017 over the entire planet, producing a 25%–40% change in the low-latitude solar heating rate according to our radiative transfer calculations. Thus, the cloud-top level atmosphere should have experienced considerable solar heating variations over this period. Our global circulation model calculations show that this variable solar heating rate may explain the observed variations of zonal wind from 2006 to 2017. Overlaps in the timescale of the long-term UV albedo and the solar activity variations make it plausible that solar extreme UV intensity and cosmic-ray variations influenced the observed albedo trends. The albedo variations might also be linked with temporal variations of the upper cloud SO2 gas abundance, which affects the H2SO4–H2O aerosol formation.

Rest-frame UV and optical emission line diagnostics of ionized gas properties: a test case in a star-forming knot of a lensed galaxy at z ∼ 1.7

Abstract We examine the diagnostic power of rest-frame ultraviolet (UV) nebular emission lines, and compare them to more commonly used rest-frame optical emission lines, using the test case of a single star-forming knot of the bright lensed galaxy RCSGA 032727–132609 at redshift $z$ ∼ 1.7. This galaxy has complete coverage of all the major rest-frame UV and optical emission lines from Magellan/MagE and Keck/NIRSPEC. Using the full suite of diagnostic lines, we infer the physical properties: nebular electron temperature (Te), electron density (ne), oxygen abundance (log (O/H), ionization parameter [log (q), and interstellar medium (ISM) pressure (log (P/k)]. We examine the effectiveness of the different UV, optical, and joint UV–optical spectra in constraining the physical conditions. Using UV lines alone we can reliably estimate log (q), but the same is difficult for log (O/H). UV lines yield a higher (∼1.5 dex) log (P/k) than the optical lines, as the former probes a further inner nebular region than the latter. For this comparison, we extend the existing Bayesian inference code izi, adding to it the capability to infer ISM pressure simultaneously with metallicity and ionization parameter. This work anticipates future rest-frame UV spectral data sets from the James Webb Space Telescope (JWST) at high redshift and from the Extremely Large Telescope (ELT) at moderate redshift.

Circumgalactic Gas at Its Extreme: Tidal Gas Streams around the Whale Galaxy NGC 4631 Explored with HST/COS

Abstract We present a detailed analysis of the absorption properties of one of the tidal gas streams around the “Whale” galaxy NGC 4631 in the direction of the quasar 2MASS J12421031+3214268. Our study is based on ultraviolet spectral data obtained with the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST) and 21cm-data from the HALOGAS project and the Green Bank Telescope (GBT). We detect strong H i Lyα absorption in the velocity range +550 to +800 km s−1 related to gas from a NGC 4631 tidal stream known as Spur 2. We measure a column density of log (N(H i/cm−2)) = 18.68 ± 0.15, indicating that the quasar sightline traces the outer boundary of Spur 2 as seen in the 21 cm data. Metal absorption in Spur 2 is detected in the lines of O i, C ii, Si ii, and Si iii in a complex absorption pattern that reflects the multiphase nature of the gas. We find that the average neutral gas fraction in Spur 2 toward 2MASS J12421031+3214268 is only 14%. This implies that ionized gas dominates the total mass of Spur 2, which then may comprise more than 109 M ☉. No significant depletion of Si is observed, showing that Spur 2 does not contain significant amounts of dust. From the measured O i/H i column density ratio, we determine an α abundance in Spur 2 of solar ([α/H] = −0.90±0.16), which is substantially lower than what is observed in the NGC 4631 disk. The low metallicity and low dust content suggest that Spur 2 represents metal-deficient gas stripped off a gas-rich satellite galaxy during a recent encounter with NGC 4631.

Laser ignition of CL-20 (hexanitrohexaazaisowurtzitane) cocrystals

Energetic cocrystals are a new class of materials that consist of two or more energetic molecules in a crystal structure. The multicomponent cocrystals can possess significantly different properties than either component, and therefore it is possible that their ignition behavior could be different than a physical mixture. In this paper, we report the time to ignition and reaction dynamics of various energetic materials, including select cocrystal materials under CO2 laser heating. An effort was made to minimize the amount of material used in comparison to previous laser ignition studies due to the limited availability of materials. The 1:1 molar Trinitrotoluene (TNT): Hexanitrohexaazaisowurtzitane (CL-20) produced by slurry or precipitation methods and 1:2 molar cyclotetramethylene-tetranitramine (HMX):CL-20 produced by slurry or resonant mixing methods were investigated along with the individual constituents and equivalent molar physical mixes. Pressed cylindrical pellets with diameters of 3.2 mm and heights between 1 and 2 mm were ignited at irradiances ranging from 310 to 1446 W/cm2. Visual imaging was performed with a high speed camera and ultraviolet (UV) spectral data were collected with a spectrometer coupled to a streak camera. Additionally, high speed schlieren imaging was performed to investigate the ignition dynamics prior to light generation. Specific species identified with the spectrometer include OH and CN, which coincide with the observation of the secondary flame as indicated from schlieren and first-light in the visual video record. All the cocrystallized materials ignited in a similar manner to CL-20 with comparable times to secondary flame formation, but the cocrystallized materials were found to have a shorter onset to gasification than the constituents or physical mixtures.

Synthesis, spectral LFER and antimicrobial activities of some (E)-N׳-(1-(substituted phenyl)ethylidene)benzohydrazides

<p class="IEEEAuthorAffiliation">About eleven substituted (<em>E</em>)-<em>N</em><em>׳</em>-(1-(substituted phenyl) ethylidene) benzo- hydrazides have been synthesized. They are characterized by their analytical, ultraviolet, infrared and NMR spectral data. The antibacterial and fungal activities of these chalcones have been evaluated.</p>

Real-time detection of organic contamination events in water distribution systems by principal components analysis of ultraviolet spectral data.

The detection of organic contaminants in water distribution systems is essential to protect public health from potential harmful compounds resulting from accidental spills or intentional releases. Existing methods for detecting organic contaminants are based on quantitative analyses such as chemical testing and gas/liquid chromatography, which are time- and reagent-consuming and involve costly maintenance. This study proposes a novel procedure based on discrete wavelet transform and principal component analysis for detecting organic contamination events from ultraviolet spectral data. Firstly, the spectrum of each observation is transformed using discrete wavelet with a coiflet mother wavelet to capture the abrupt change along the wavelength. Principal component analysis is then employed to approximate the spectra based on capture and fusion features. The significant value of Hotelling's T2 statistics is calculated and used to detect outliers. An alarm of contamination event is triggered by sequential Bayesian analysis when the outliers appear continuously in several observations. The effectiveness of the proposed procedure is tested on-line using a pilot-scale setup and experimental data.

Changes in the phenolic acids composition during pancake preparation: Whole and refined grain flour and processed food classification by UV and NIR spectral fingerprinting method—Proof of concept

We investigated the changes in the levels of phenolic acids during pancake preparation (flour to batter-pancake) from two refined and whole-wheat wheat varieties. In addition, we evaluated if multivariate analysis of ultraviolet (UV) and near infrared (NIR) spectral fingerprinting data can be used for classification of samples based on preparation stage, wheat varieties, and flour types (whole and refined). Results indicated that total phenolic acids did not significantly change (< 10%) during preparation of pancake from the refined and whole wheat flours. Most (> 90%) of the phenolic acids existed in insoluble bound form and ferulic acid (82–92%) was the most abundant phenolic acid. Correlation between simple UV spectral scan and HPLC analysis for the assay of phenolic acids ranged from 0.771 to 1.00. Principle component analysis (PCA) of NIR spectral data from 4900 to 5900cm−1 showed clear separation between flour, batter, and pancake. Additionally, the PCA of UV spectral data between 250 and 350nm separated two into clusters well (refined and whole-wheat samples). The results presented in this manuscript with limited number of samples illustrate the proof of concept that spectral fingerprinting techniques show promising potential for whole and refined grains sample classification and their products.

Synthesis and antimicrobial activities of some (E)-N'-1-(substituted benzylidene)benzohydrazides

About ten substituted (E)-N'-1-(substituted benzylidene) benzohydrazides have been synthesized. They are analyzed by their analytical, ultra violet (UV), Fourier transform-IR (FT-IR) and nuclear magnetic resonance (NMR) spectral data and evaluated by antimicrobial activities such antibacterial and antifungal activities.

Identification and Characterization of Metabolites of Irinotecan in-vivo and in-vitro matrixes by HPLC/LC-MS

In the present study metabolite identification and characterization has done by using HPLC and LC-MS. During method development various mobile phases have tried for identification of metabolites. The matrixes selected for in- vivo study were urine because nearly all the metabolites of irinotecan were obtained in it. The extraction mixtures have selected to retain maximum amount of analyte with less effort. During experiment four extraction solvents were used in six different concentrations out of which TBME suit our method. In-vitro study done by Human Liver microsomes by using Phosphate buffer (pH 7.4) and NADPH as co-factors for initiation of enzymatic reaction. Irinotecan is a prodrug that is converted in the liver to an active metabolite, SN-38. It is eliminate in Bile and Faeces and thus its dose reduced in Hepatic Failure. Irinotecan act by inhibiting Topoisomerase-1.It is the enzyme which nicks, introduces negative supercoils and reseals the DNA strand. Conventionally, drug metabolite identification in the past has usually been based on the comparison of ultraviolet (UV) spectral data and high-performance liquid chromatography (HPLC) retention times of isolated ‘unknown’ metabolites with those of synthesised standards. Such a method of detecting and characterising drug metabolites is an uncertain, time-consuming and expensive process, as well as affording very limited structural information. Furthermore, Phase I metabolism of a drug candidate often results in only minor structural modification of the parent compound; these minor changes can make it particularly difficult to determine suitable chromatographic conditions to effect HPLC separation of metabolites. This study describes contemporary approach to identification and characterization of xenobiotic metabolites in complex biological fluids derived from drug metabolism studies.

High-throughput identification of monoclonal antibodies after compounding by UV spectroscopy coupled to chemometrics analysis.

Monoclonal antibodies (mAbs) compounded into the hospital pharmacy are widely used nowadays. Their fast identification after compounding and just before administration to the patient is of paramount importance for quality control at the hospital. This remains challenging due to the high similarity of the structure between mAbs. Analysis of the ultraviolet spectral data of four monoclonal antibodies (cetuximab, rituximab, bevacizumab, and trastuzumab) using unsupervised principal component analysis led us to focus exclusively on the second-derivative spectra. Partial least squares-discriminant analysis (PLS-DA) applied to these data allowed us to build models for predicting which monoclonal antibody was present in a given infusion bag. The calibration of the models was obtained from a k-fold validation. A prediction set from another batch was used to demonstrate the ability of the models to predict well. PLS-DA models performed on the spectra of the region of aromatic amino acid residues presented high ability to predict mAb identity. The region corresponding to the tyrosine residue reached the highest score of good classification with 89%. To improve the score, standard normal variate (SNV) preprocessing was applied to the spectral data. The quality of the optimized PLS-DA models was enhanced and the region from the tyrosine/tryptophan residues allowed us excellent classification (100%) of the four mAbs according to the matrix of confusion. The sensitivity and specificity performance parameters assessed this excellent classification. The usefulness of the combination of UV second-derivative spectroscopy to multivariate analysis with SNV preprocessing demonstrated the unambiguous identification of commercially available monoclonal antibodies. Graphical abstract PLS-DA models on the spectra of the region of aromatic amino acid residues allows mAb identification with high prediction.

First simultaneous SST/CRISP and IRIS observations of a small-scale quiet Sun vortex

Ubiquitous small-scale vortices have recently been found in the lower atmosphere of the quiet Sun in state-of-the-art solar observations and in numerical simulations. We investigate the characteristics and temporal evolution of a granular-scale vortex and its associated upflows through the photosphere and chromosphere of a quiet Sun internetwork region. We analyzed high spatial and temporal resolution ground- and spaced-based observations of a quiet Sun region. The observations consist of high-cadence time series of wideband and narrowband images of both H-alpha 6563 A and Ca II 8542 A lines obtained with the CRisp Imaging SpectroPolarimeter (CRISP) instrument at the Swedish 1-m Solar Telescope (SST), as well as ultraviolet imaging and spectral data simultaneously obtained by the Interface Region Imaging Spectrograph (IRIS). A small-scale vortex is observed for the first time simultaneously in H-alpha, Ca II 8542 A, and Mg II k lines. During the evolution of the vortex, H-alpha narrowband images at -0.77 A and Ca II 8542 A narrowband images at -0.5 A, and their corresponding Doppler Signal maps, clearly show consecutive high-speed upflow events in the vortex region. These high-speed upflows with a size of 0.5-1 Mm appear in the shape of spiral arms and exhibit two distinctive apparent motions in the plane of sky for a few minutes: (1) a swirling motion with an average speed of 13 km/s and (2) an expanding motion at a rate of 4-6 km/s. Furthermore, the spectral analysis of Mg II k and Mg II subordinate lines in the vortex region indicates an upward velocity of up to about 8 km/s along with a higher temperature compared to the nearby quiet Sun chromosphere. The consecutive small-scale vortex events can heat the upper chromosphere by driving continuous high-speed upflows through the lower atmosphere.

Autonomous Portable Solar Ultraviolet Spectroradiometer (APSUS) – a New CCD Spectrometer System for Localized, Real‐Time Solar Ultraviolet (280–400 nm) Radiation Measurement

Terrestrial solar ultraviolet (UV) radiation has significant implications for human health and increasing levels are a key concern regarding the impact of climate change. Monitoring solar UV radiation at the earth's surface is therefore of increasing importance. A new prototype portable CCD (charge-coupled device) spectrometer-based system has been developed that monitors UV radiation (280-400nm) levels at the earth's surface. It has the ability to deliver this information to the public in real time. Since the instrument can operate autonomously, it is called the Autonomous Portable Solar Ultraviolet Spectroradiometer (APSUS). This instrument incorporates an Ocean Optics QE65000 spectrometer which is contained within a robust environmental housing. The APSUS system can gather reliable solar UV spectral data from approximately April to October inclusive (depending on ambient temperature) in the UK. In this study the new APSUS unit and APSUS system are presented. Example solar UV spectra and diurnal UV Index values as measured by the APSUS system in London and Weymouth in the UK in summer 2012 are shown.

In situ generation of trityl carbocation (Ph3C+) as a homogeneous organocatalyst for the efficient synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s

Trityl chloride (Ph 3 CCl) efficiently catalyzes the condensation of 3-methyl-1-phenyl-1 H -pyrazol-5(4 H )-one and aromatic aldehydes under mild and solvent-free conditions, affording 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1 H -pyrazol-5-ol)s in high to excellent yields and in short reaction time. The presence of the requisite organocatalytic trityl carbocation (Ph 3 C + ) species was confirmed by analysis of infrared, 1 H NMR, and ultra violet spectral data. A plausible mechanism was proposed for the reaction based on the observations and literature precedent. Efficient synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1 H -pyrazol-5-ol)s from 3-methyl-1-phenyl-1 H -pyrazol-5(4 H )-one and arylaldehydes using Ph 3 CCl under solvent-free conditions is described. A plausible reaction mechanism for the process based on the experimental data and that from similar literature studies is proposed.