Miracle-dz/UniFAR-FTUs huggingface dataset:
N‐bromosuccinimide reactions of some heterocycles in the presence or absence of water: An overview of ring versus side chain bromination for the synthesis of important brominated heterocyclic synthons

Reactions of various heterocycles 1–6 with N-bromosuccinimide in the presence or absence of water have been studied for side chain versus ring bromination to afford some new and important heterocyclic synthons. Interestingly, the N-bromosuccinimide reaction in the presence of perchloric acid, a new condition, affords exclusively the new dibromo aminopicoline 1f, which is not obtained by other presently studied methods.
New software for finding transition states by probing accessible, or ergodic, regions

An automated, iterative approach to finding the lowest energy, ionic diffusion paths through a periodic structure has been developed within our new code (written in FORTRAN 77 and named Bubble). The approach is quite general in that it can be applied to find, at a chosen temperature, the accessible (ergodic) regions of a hyper-surface, which is defined across a uniform grid [1]. We describe both our implementation within the Bubble code and its application to locating the approximate transition states for Mg interstitial diffusion in forsterite, which can then be refined using standard transition state searching [2].
Presenting Analytical Performances of Electrochemical Sensors. Some Suggestions

A description of the performances of new electrochemical sensors is important for evaluating their novelty and potential applicability to the analysis of real samples. However, it was noticed that quite often some figures of merit were ill-defined or reported in an inadequate format. Based on some well-known books and guidelines, some simple approaches are briefly reviewed which allow a better estimation of the most frequently reported figures of merit. Adopting these approaches implies a certain increase of cost and time of the given investigations. But the results would benefit from an easier acceptance by the scientific community.
Micronutrient supplying power of pyrite and fly ash

Abstract Bush bean plants (Phaseolus vulgaris L. cv Improved Tendergreen) were grown in nutrient solution with added waste mine tailings pyrite and also coal fly ash to test their ability to supply micronutrients to plants. The ability of fly ash to supply K was also tested. The pyrite was a satisfactory source of Fe, Mn, Zn, B and Cu to the solution cultures. The pyrite also supplied Ca. The fly ash supplied inadequate Fe and Mn but adequate quantities of Zn, B and Cu. It supplied adequate Ca and inadequate K. Both pyrite and fly ash supplied some Cd (when solution was acid), Cr and Pb to roots but not in detectable amounts to shoots. In another experiment, fly ash also failed to supply K to bush bean plants and failed to supply Zn. Iron, B, Si, Cu, Mo, Sr, Ba and some Ni and Cr were supplied to leaves; Si, Sr, Ba, Ni and Cr were supplied to roots by the fly ash. None of these elements seemed to result in phytotoxicity. A suggestion is made that fly ash and pyrite could be blended for soil application of.
Initial lithography results from the digital electrostatic e-beam array lithography concept

The Digital Electrostatically focused e-beam Array direct-write Lithography (DEAL) concept is currently under development at Oak Ridge National Laboratory (ORNL). This concept incorporates a digitally addressable field-emission array (DAFEA) built into a logic and control integrated circuit to function as the write head for an e-beam lithography tool. The electrostatic focusing is integrated on the DAFEA and consists of additional grids lithographically aligned above the emitters and extraction grid, each separated by a dielectric (nominally low-temperature SiO2) layer. Prototypes of the DAFEA have been fabricated and used to test the focusing of the electron beams and to pattern lines in PMMA resist. First lithography tests have used electron energies of 500 eV to pattern lines less than 1 μm wide at a working distance of 500 μm which extrapolates to <300nm at the nominal DEAL design working distance of 100 μm. Aspects of the DEAL lithography testing and further development are discussed.
Synthesis and properties of poly(methyl methacrylate)/clay nanocomposites using natural montmorillonite and synthetic Fe‐montmorillonite by emulsion polymerization

In this article, Fe-montmorillonite (Fe-MMT) was synthesized by hydrothermal method. For the first time, Fe-MMT was modified by cetyltrimethyl ammonium bromide (CTAB), and poly(methyl methacrylate)(PMMA)/Fe-MMT nanocomposites were synthesized by emulsion polymerization. Then poly(methyl methacrylate)(PMMA)/natural montmorillonite (Na-MMT) and PMMA/Fe-MMT nanocomposites were compared by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) patterns, transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). By XRD and TEM, it was found out that the morphology of PMMA/Fe-MMT nanocomposites was different from that of the PMMA/Fe-MMT nanocomposites when the content of two types of clay was same in the PMMA matrix. It was possible that the presence of iron may lead to some radical trapping, which enhances intragallery polymerization to be developed to improve layer dispersion in PMMA/Fe-MMT systems. In TGA curves, the thermal stability and residue at 600°C of PMMA/Fe-MMT nanocomposites were higher than those of PMMA/Na-MMT nanocomposites. Those dissimilarities were probably caused by structural Fe ion in the lattice of Fe-MMT. POLYM. COMPOS. , 27:49–54, 2006. © 2005 Society of Plastics Engineers
A study of 732.0 nm dayglow emission at the equator under varying atomic oxygen density conditions for equinox and solstice cases

A comprehensive model is developed to compute the volume emission rate of O+(2P) 732.0 nm dayglow emission. The modeled volume emission rates are compared with the measurements as provided by Atmosphere Explorer C satellite and Dynamics Explorer 2 spacecraft. It is found that the model explains quite well the measured emission profiles. The present model is used to study the effect of atomic oxygen abundance on the volume emission rate of 732.0 nm dayglow emission at the equator for equinox and solstice. To study the effect of atomic oxygen abundance on 732.0 nm dayglow emission, the atomic oxygen number densities obtained from the NRLMSISE‐00 model are increased (or decreased) in an increment (or decrement) of 20% and are incorporated into the model to compute volume emission rate profiles. The present study shows that the peak emission rate (PER) varies linearly below the reference level of atomic oxygen number density and does not vary linearly above the reference level of atomic oxygen number density. The atomic oxygen number density at reference level corresponds to that value which is obtained from the NRLMSISE‐00 model. It is found that the altitude of peak emission rate moves upward as the F10.7 solar index increases. On average the upward movement of altitude of PER is about 9 km for both the equinox and solstice cases. The upward movement of the altitude of peak emission rate is due to the enhancement in atomic oxygen number density with increase in F10.7 solar index.
Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Despite the acknowledged relevance of aerosol-derived water-soluble organic carbon (WSOC) to climate and biogeochemical cycling, characterization of aerosol WSOC has been limited. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was utilized in this study to provide detailed molecular level characterization of the high molecular weight (HMW; m/z>223) component of aerosol-derived WSOC collected from rural sites in Virginia and New York, USA. More than 3000 peaks were detected by ESI FT-ICR MS within a m/z range of 223–600 for each sample. Approximately 86% (Virginia) and 78% (New York) of these peaks were assigned molecular formulas using only carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S) as elemental constituents. H/C and O/C molar ratios were plotted on van Krevelen diagrams and indicated a strong contribution of lignin-like and lipid-like compounds to the aerosol-derived WSOC samples. Approximately 1–4% of the peaks in the aerosol-derived WSOC mass spectra were classified as black carbon (BC) on the basis of double bond equivalents calculated from the assigned molecular formulas. In addition, several high-magnitude peaks in the mass spectra of samples from both sites corresponded to molecular formulas proposed in previous secondary organic aerosol (SOA) laboratory investigations indicating that SOAs are important constituents of the WSOC. Overall, ESI FT-ICR MS provides a level of resolution adequate for detailed compositional and source information of the HMW constituents of aerosol-derived WSOC.
A Study On High Dimensional Clustering By Using Clique

In real life clustering of high dimensional data is a big problem. To find out the dense regions from increasing dimensions is one of them. We have already studied the clustering techniques of low dimensional data sets like k-means, k-mediod, BIRCH, CLARANS, CURE, DBScan, PAM etc. If a region is dense then it consists with number of data points with a minimum support of input parameter ø other wise it cannot take into clustering. So in this approach we have implemented CLIQUE to find out the clusters from multidimensional data sets. In dimension growth subspace clustering the clustering process start at single dimensional subspaces and grows upward to higher dimensional ones. It is a partition method where each dimension divided like a grid structure. The grid is a cell where the data points are present. We check the dense units from the structure by applying different algorithms. Finally the clusters are formed from the high dimensional data sets. KeywordsCLIQUE, APRIORI, DENSE UNIT
Conversion of rice hull ash into soluble sodium silicate

Sodium silicate is used as raw material for several purposes: silica gel production, preparation of catalysts, inks, load for medicines, concrete hardening accelerator, component of detergents and soaps, refractory constituent and deflocculant in clay slurries. In this work sodium silicate was produced by reacting rice hull ash (RHA) and aqueous sodium hydroxide, in open and closed reaction systems. The studied process variables were time, temperature of reaction and composition of the reaction mixture (expressed in terms of molar ratios NaOH/SiO2 and H2O/SiO2). About 90% silica conversion contained in the RHA into sodium silicate was achieved in closed system at 200 °C. The results showed that sodium silicate production from RHA can generate aggregate value to this residue.
Advances in Sampling and Analysis for Aflatoxins in Food and Animal Feed

Advances in analytical methods and novel detection systems are reviewed from publications from 1995 onwards. The review covers aflatoxins B1, B2, G1, G2, and their metabolites in food, animal feed and biological matrices such as blood and urine. Improved extraction techniques, new clean‐up methods and optimized methods for specific matrices are summarized. This review highlights methods such as thin layer chromatography (TLC) and high performance‐TLC (HPTLC), which are particularly suited to developing countries, and advances that have been made in TLC quantification through low cost detection and scanning systems. Novel developments in detection of aflatoxins are assessed such as the application of surface plasmon resonance biosensors, flow injection monitoring, fibre optic sensors, capillary electrokinetics, electrochemical transduction, and immunological‐based rapid test kits. Recent advances in confirmatory techniques such as liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (MS/MS) for aflatoxins are also covered. This review summarizes performance data from recent collaborative studies, and assesses the overall quality of analytical data for aflatoxins being produced worldwide, as evidenced by results from various proficiency testing schemes. Although there are only a few recent studies on sampling for aflatoxins, the recent progress in this area is also assessed.
Kinetic Spectrophotometric Analysis and Spectrofluorimetric Analysis of Ciprofloxacin Hydrochloride and Norfloxacin in Pharmaceutical Preparations Using 4‐Chloro‐7‐Nitrobenzo‐2‐Oxa‐1,3‐Diazole (NBD‐Cl)

Simple, reliable, sensitive and accurate kinetic spectrophotometric and spectrofluorimetric methods were proposed for the determination of ciprofloxacin hydrochloride (CPX) and norfloxacin (NRX) in pure form and in pharmaceuticals. The methods are based on coupling the studied drugs with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in the presence of alkaline borate buffer. Spectrophotometric measurement was achieved by recording the absorbance at 477 nm after a fixed time of 20 and 15 min on a water bath adjusted at 70 ± 1 °C for CPX and NRX, respectively. The same product exhibited emission peaks at 540 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The absorbance concentration plots were linear over the ranges 3-18 and 2.5-15.0 μg/mL for CPX and NRX, respectively, while the fluorescence concentration plots were linear over the ranges 0.06-0.36 and 0.05-0.30 μg/mL for CPX and NRX, respectively. The limit of detection of the kinetic method was about 0.2 μg/mL for both drugs while the fluorescence measurement enabled their detection at a concentration of about 0.012 μg/mL. The proposed methods were successfully applied for the assay of the two drugs in their commercial products. The results obtained were statistically compared with those obtained by reference HPLC and spectrophotometric methods. The stoichiometry of the reaction was determined and the reaction pathway was postulated.
Temperature control of a cyclotron magnet for stabilization of the JAERI AVF cyclotron beam

Frequent corrections of the magnetic field of the JAERI AVF cyclotron were required for keeping a beam current constant during long time operation. We observed correlation between the magnetic field and the temperature of the cyclotron magnet yoke by measuring the magnetic field with an NMR probe and the temperature with platinum resistance thermometers. As a result, this instability of a cyclotron beam was induced by temperature-change of the magnet yoke caused mainly by thermal conduction from the main coil. To restrain the thermal conduction to the yoke, we have inserted temperature-controlled copper plates between the yoke and the main coil. In addition, a temperature control system for the cooling water of the trim coils has been installed, which is independent of the total cooling system for controlling the pole tip temperature. An optimum condition of the temperature control systems for stabilizing the magnetic field has been investigated.
Flexible Janus Nanofibers: Facile Electrospinning Construction and Enhanced Luminescent–Electrical–Magnetic Trifunctionality

Flexible luminescent–electrical–magnetic trifunctional Janus nanofibers have been successfully fabricated through electrospinning technology by using specially designed parallel spinnerets. The terbium complex [Tb(ba)3(phen)] (BA=benzoic acid, phen=1,10-phenanthroline), polyaniline (PANI), and Fe3O4 nanoparticles (NPs) were incorporated into polyvinyl pyrrolidone (PVP) and electrospun into Janus nanofibers with [Tb(ba)3(phen)]/PVP as one strand of the nanofiber and PANI/Fe3O4/PVP as another. The morphologies and properties of the final products were investigated in detail by XRD, SEM, TEM, fluorescence spectroscopy, Hall effect measurement system, and vibrating sample magnetometry. The [[Tb(ba)3(phen)]/PVP]//[PANI/Fe3O4/PVP] Janus nanofibers, with an average diameter of 180 nm, simultaneously possess enhanced luminescent performance, electrical conduction, and magnetism. Fluorescence emission peaks of Tb3+ are observed in the [[Tb(ba)3(phen)]/PVP]//[PANI/Fe3O4/PVP] Janus nanofibers and assigned to the 5D45F6 (λ=491 nm), 5D45F5 (λ=544 nm), 7D45F4 (λ=585 nm), and 5D47F3 (λ=620 nm) energy-level transitions of Tb3+ ions; the 5D45F5 hypersensitive transition at λ=544 nm is the predominant emission peak. The electrical conductivity of Janus nanofibers reaches up to the order of 10−3 S cm−1. The luminescent intensity, electrical conductivity, and magnetic properties of Janus nanofibers can be tunable by adjusting the amounts of rare-earth complex, PANI, and Fe3O4 NPs present. This new type of luminescent–electrical–magnetic trifunctional Janus nanofiber holds potential for a variety of applications, including molecular electronics, microwave absorption, and future nanodevices, owing to their excellent fluorescence, electrical conduction, and magnetism.
Soil organic carbon stock variability in the Northern Gangetic Plains of India: interaction between agro‐ecological characteristics and cropping systems

Soil organic carbon (SOC) content and its spatial distribution in the Northern Gangetic Plain (NGP) Zone of India were determined to establish the cause–effect relationship between agro‐ecological characteristics, prevailing crop management practices and SOC stock. Area Spread Index (ASI) approach was used to collect soil samples from the NGP areas supporting predominant cropping systems. Exponential ordinary kriging was found most suitable geo‐statistical model for developing SOC surface maps of the NGP. Predicted surface maps indicated that 43.7% area of NGP had 0.5–0.6% SOC, while the rest of the area was equally distributed with high (0.61–0.75%) and low (< 0.5%) SOC content levels. Averaged across cropping systems, maximum SOC content was recorded in Bhabar and Tarai Zone (BTZ), followed by Central Plain Zone (CPZ), Mid‐Western Plain Zone (MWPZ), Western Plain Zone (WPZ) and South‐Western Plain Zone (SWPZ) of the NGP. The SOC stock was above the optimum threshold (> 12.5 Mg/ha) in 97.8, 57.6 and 46.4% areas of BTZ, CPZ and MWPZ, respectively. Only 9.8 and 0.4% area of WPZ and SWPZ, respectively, had SOC stock above the threshold value. The variation in SOC stock was attributed largely to carbon addition through recycling of organic sources, cropping systems, tillage intensity, crop or residue cover and land‐use efficiency, nutrient‐use pattern, soil texture and prevailing ecosystem. Adoption of conservation agriculture, balanced use of nutrients, inclusion of legumes in cropping systems and agro‐forestry were suggested for enhancing SOC stock in the region.
An Atomistic Modeling and Quantum Mechanical Approach to the Hydrolytic Degradation of Aliphatic Polyesters

This paper reports computational simulations at two different scales employed to investigate the hydrolytic degradation of two homopolyesters: polyglycolide, PGA and poly(L-lactide), PLLA. Atomistic bulk models were used to investigate the dry and various hydrated states of the two systems. In addition, the first moments of contact between the polymers and water were studied employing atomistic interface models. A higher affinity of water to polyglycolide in comparison with poly(L-lactide) was observed, while diffusion of water was found to be lower in the first polymer. Quantum chemical calculations for the first step of the water-assisted hydrolysis revealed a higher resistance to hydrolytical scission of the L-lactyl units in comparison to glycolyl units.
Water auditing: the case for statutory requirements

Drought across swathes of Australia, highlights our need for water conservation in addition to seeking new sources of water (demand and supply-side resource options). Water conservation or efficiency improvement is currently a non-systematic process along the lines of ‘if we do such and such then we will save so much water’. Such an approach is ad-hoc and only has the appearance of being ‘quantitative’. We would class it as qualitative, or maybe advanced qualitative water conservation. True quantitative or structured water auditing of non-domestic water consumption is an iterative, systematic and documented process of obtaining reliable use data, validated by a closure approach. Opportunities are identified for water use reduction, water reuse, recycling and for water resource substitution. Financial assessment of savings in cost against cost of measures will provide a payback period. A water management strategy or Water Management Plan (WMP) as it is known in Victoria, Australia, is devised which is consistent with legal requirements, the enterprise9s environmental policy and its movement towards sustainable development. Regulators have legislated for mandatory WMPs and audits in Victoria, but this is the only state so far to do this. Mandatory water auditing should be an uncontested choice as it can only provide a win:win situation regulation to the private sector. We argue that only the systematic process provided by structural water auditing constitutes quantitative water conservation. Further, statutory obligation for water users to engage in the water auditing process will give the broad, systematic quantitative information, and based upon which optimal water management strategies or WMPs can be devised. This will ensure a rational approach to our future water needs and the needs of our environment. It is anticipated that voluntary auditing in the arenas not mandated will increase in the long term if this is done.
Synthesis, Absorption, and Fluorescence‐Emission Properties of 1,3,6,8‐Tetraethynylpyrene and Its Derivatives

The synthesis of several 1,3,6,8-tetraethynylpyrene derivatives is reported. The effect of extended acetylenic conjugation on their absorption and fluorescence-emission properties is studied. Significant bathochromic shifts of both the absorption and fluorescence emission bands are observed. These derivatives emit fluorescence in the visible (400–550 nm) region. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A high-resolution mass spectrometer to measure atmospheric ion composition

Abstract. In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG). Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools) were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm−3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (poly)alkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.