Miracle-dz/UniFAR-FTUs huggingface dataset:
Structure and Properties of Nanocomposites Based on Nylon-11 and -12 Compared with Those Based on Nylon-6

An in-depth analysis was made on the effect of polyamide repeat structure on the morphology and mechanical properties of nanocomposites based on nylon-6, nylon-11, and nylon-12. Special care was taken to make comparisons under fixed thermal and rheological conditions. Increasing the aliphatic content relative to nylon-6 results in a decrease in the extent of organoclay exfoliation as revealed by transmission electron photomicrographs. The extent of platelet separation as judged by low-angle X-ray scattering is more complicated for nylon-11 and -12 nanocomposites than those based on nylon-6 due the presence of crystalline peaks associated with the polyamide matrix. An “exfoliation index” is used to compare stiffness effects observed in the different nanocomposites due to the large difference in the modulus of nylon-6 as compared to nylon-11 and -12. Interestingly, the exfoliation efficiency parallels morphological trends in that nylon-6 exhibits higher efficiencies than the more aliphatic nylon-11 and -12 .
Visual detection of Maize chlorotic mottle virus using unmodified gold nanoparticles

Maize chlorotic mottle virus causes corn lethal necrosis disease, and can be transmitted via infected maize seeds. It remains a challenge to detect this virus to prevent its introduction, infection and its transmission throughout fields. For this purpose, visual detection of Maize chlorotic mottle virus was investigated using unmodified gold nanoparticles (AuNPs). Detection relies on the fact that the dispersed AuNP solution is red due to the intense surface plasmon absorption band at 520 nm, whereas the AuNP solution in the presence of the species-specific probes and RT-PCR target products of Maize chlorotic mottle virus is grey blue after saline induction. After optimization of the size of the AuNPs, concentration of NaCl, probes in the reaction system and evaluation of the specificity and sensitivity of a novel assay, visual detection of Maize chlorotic mottle virus using unmodified AuNPs has been developed with simple preparation of samples in our study. Through this assay, as low as 30 pg μL−1 of RNA of Maize chlorotic mottle virus was detected visually, by the naked eye, without the need for any sophisticated, expensive instrumentation and biochemical reagents. The specificity was 100% and the assay exhibited good reproducibility in 15 sample viruses. The results indicate that this assay is highly species-specific, simple, low-cost, and visual for easy detection of Maize chlorotic mottle virus in plant tissues. Therefore, visual detection of Maize chlorotic mottle virus is a potentially useful tool for middle or small-scale corporations and entry-exit inspection and quarantine bureaus to detect Maize chlorotic mottle virus in maize seeds or plant tissues.
A COMPUTATIONAL STUDY ON SOME SELENIUM-CONTAINING NAPHTHALENE DERIVATIVES

A quantum chemical study, based on DFT theory is presented which considers certain selenium-containing naphthalene derivatives, including a keto group together with a Se atom embedded in either a five- or six-membered ring fused with naphthalene moiety. The corresponding enol structures also are considered. The quantum chemical and IR data collected are analyzed and NICS(0) values have been obtained.
Enhanced Photocatalytic Activity using Layer‐by‐Layer Electrospun Constructs for Water Remediation

Endocrine disruptors such as bisphenol A (BPA) are environmental pollutants that interfere with the body's endocrine system because of their structural similarity to natural and synthetic hormones. Due to their strong oxidizing potential to decompose such organic pollutants, colloidal metal oxide photocatalysts have attracted increasing attention for water detoxification. However, achieving both long‐term physical stability and high efficiency simultaneously with such photocatalytic systems poses many challenges. Here a layer‐by‐layer (LbL) deposition approach is reported for immobilizing TiO2 nanoparticles (NPs) on a porous support while maintaining a high catalytic efficiency for photochemical decomposition of BPA. Anatase TiO2 NPs ≈7 nm in diameter self‐assemble in consecutive layers with positively charged polyhedral oligomeric silsesquioxanes on a high surface area, porous electrospun polymer fiber mesh. The TiO2 LbL nanofibers decompose approximately 2.2 mg BPA per mg of TiO2 in 40 h of illumination (AM 1.5G illumination), maintaining first‐order kinetics with a rate constant (k) of 0.15 h−1 for over 40 h. Although the colloidal TiO2 NPs initially show significantly higher photocatalytic activity (k ≈ 0.84 h−1), the rate constant drops to k ≈ 0.07 h−1 after 4 h of operation, seemingly due to particle agglomeration. In the BPA solution treated with the multilayered TiO2 nanofibers for 40 h, the estrogenic activity, based on human breast cancer cell proliferation, is significantly lower than that in the BPA solution treated with colloidal TiO2 NPs under the same conditions. This study demonstrates that water‐based, electrostatic LbL deposition effectively immobilizes and stabilizes TiO2 NPs on electrospun polymer nanofibers for efficient extended photochemical water remediation.
Struktur Komunitas dan Kelimpahan Fitoplankton serta Keterkaitannya dangan Paramater Fisik Kimia di Perairan Pesisir Banyuasin Kabupaten Banyuasin

Changes in water quality is closely related to the abundance and phytoplankton community structure so that the presence of phytoplankton in the waters can provide information about the condition of a body of water. The purpose of this study was to evaluate the physical and chemical parameters of coastal Banyuasin, analyze the abundance and community stucture of phytoplankton abundance of phytoplankton and analyzing linkages with physico-chemical associations with chemical physics parameters in the coastal waters of South Sumatera Banyuasin was held on June 15, 2015. The determination of the research station using purposive sampling method. Phytoplankton samples taken using plankton nets (Plankton net) with a mesh size of 25 μm. Identification of phytoplankton are carried out in the laboratory by observing under a microscope and using phytoplankton identification book. The influence of enviromental parameters on the abundance of phytoplankton processed by PCA using STATISTICA software. The result showed that the phytoplankton were found composed of there classes which Bacillariophyceae, Dinophyceae and Cyanophyceae. The most common genus is Skeletonema. Value abundance of phytoplankton ranged from 78 cells/1-329 cells/1, Diversity Index (H’) ranged from 0,377 to 1,785, Index Uniformity (E) ranges from 0,234 to 0,772, and the index Dominance (C) ranges between 0214-0851. Principal Component Analysis of phytoplankton abundance correlated positively with nitrate (NO3+), salinity and pH, whreas phospate (PO4+), DO, temparature, brightness and speed of flow showed a negative correlation.
Position transitions of polymer-grafted nanoparticles in diblock-copolymer nanocomposites

Self-assembly of block copolymer/nanoparticle blends has promising applications in the design and fabrication of novel functional nanomaterials. Precise control of the spatial positions of nanoparticles within block copolymer-based nanomaterials is crucial to achieve some special physical properties and functions. Here, we employ the self-consistent field method to theoretically investigate the self-assembly of polymer grafted-nanoparticles in a diblock copolymer. It is found that by varying the size and selectivity of nanoparticles, one can not only produce various self-assembled nanostruc- tures but also modulate the spatial positions of the nanoparticles, either at the copolymer interfaces or in the center of one copolymer phase, within the nanostructures. A denser grafted polymer brush plays a role of shielding effect on nanoparti- cles and can position them into the center of one copolymer phase. The nanostructural transition we observed is dictated by the competition between entropy and enthalpy. On the basis of a number of simulations, two phase diagrams of self-assem- bled nanostructures are constructed. This study may be helpful for optimal design of advanced materials with desired nanostructures and enhanced performance.
Nanowire Interconnects for Printed Large‐Area Semitransparent Organic Photovoltaic Modules

Semitransparent organic photovoltaic (OPV) cells promise applications in various transparent architectures where their opaque counterparts cannot contribute. Realizing practical applications of this technology requires the manufacturing of large‐area modules without significant performance loss compared to the lab‐scale devices. In this work, efficient semitransparent OPV modules based on ultrafast laser patterning on both glass and flexible substrates are reported. Solution‐processed metallic silver nanowires (AgNWs) are used as transparent top electrodes. The efficient low‐ohmic contact of the interconnects between the top AgNWs and the bottom electrode in combination with high‐precision laser beam positioning system allow to fabricate semitransparent modules with high electrical fill factor of ≈63% and a remarkable geometric fill factor exceeding 95%, respectively. These results represent an important progress toward upscaling of high‐performance OPV modules with reduced production costs.
Computational studies on the infrared vibrational spectra, thermodynamic properties, detonation properties, and pyrolysis mechanism of octanitrocubane

The molecular geometries, infrared vibrational spectra, and thermodynamic properties of octanitrocubane (ONC) are calculated using the density functional theory (DFT) method at the B3LYP/6-31G* level. The IR frequency scaling factor 0.9501 suitable for polynitrocubanes is obtained at the B3LYP/6-31G* level, and the calculated IR frequencies of ONC are scaled. The accurate heat of formation 726.47 kJ/mol of ONC in gas phase is obtained via designed isodesmic reaction in which the cubane cage skeleton has been kept. The sublimation enthalpy, density, and heat of formation for ONC crystal are also calculated, and they are 220.63 kJ/mol, 2.189 g/cm3, and 505.84 kJ/mol, respectively. In addition, the estimated detonation velocity and detonation pressure of ONC are 10.26 mm/ms and 520.86 kbar, respectively. Finally, the pyrolysis mechanism of ONC is studied using various theoretical methods, i.e., MP2, DFT, and selected MINDO/3 semiempirical MO, based on the unrestricted Hartree–Fock model. The calculated resul.
Comparative ecosystem–atmosphere exchange of energy and mass in a European Russian and a central Siberian bog II. Interseasonal and interannual variability of CO2 fluxes

Abstract Net ecosystem–atmosphere exchange of CO2 (NEE) was measured in two boreal bogs during the snow-free periods of 1998, 1999 and 2000. The two sites were located in European Russia (Fyodorovskoye), and in central Siberia (Zotino). Climate at both sites was generally continental but with more extreme summer–winter gradients in temperature at the more eastern site Zotino. The snow-free period in Fyodorovskoye exceeded the snow-free period at Zotino by several weeks. Marked seasonal and interannual differences in NEE were observed at both locations, with contrasting rates and patterns. Amongst the most important contrasts were: (1) Ecosystem respiration at a reference soil temperature was higher at Fyodorovskoye than at Zotino. (2) The diurnal amplitude of summer NEE was larger at Fyodorovskoye than at Zotino. (3) There was a modest tendency for maximum 24 h NEE during average rainfall years to be more negative at Zotino (−0.17 versus −0.15 mol m−2 d−1), suggesting a higher productivity during the summer months. (4) Cumulative net uptake of CO2 during the snow-free period was strongly related to climatic differences between years. In Zotino the interannual variability in climate, and also in the CO2 balance during the snow-free period, was small. However, at Fyodorovskoye the bog was a significant carbon sink in one season and a substantial source for CO2-C in the next, which was below-average dry. Total snow-free uptake and annual estimates of net CO2-C uptake are discussed, including associated uncertainties.
Establishing the spatial variability of ambient nitrogen dioxide in Windsor, Ontario

This study is aimed at identifying the determinants of intra‐urban variation in ambient concentrations of nitrogen dioxide (NO2) in Windsor, Ontario, Canada, and to develop a model to predict NO2 in the city. NO2 samples were collected over a two‐week period during winter 2004 by using passive samplers in 50 locations across Windsor. A land use regression (LUR) model was constructed to generate independent variables that could best predict NO2 concentrations across the city. We tested 71 variables of land use, traffic, road characteristics, population and dwelling counts, and physical geographic variables such as elevation. The final model contained five variables: distance to the Ambassador Bridge, daily traffic on Class 1 and Class 2 arterial roads within 400 m, industry within 600 m, and total population within 700 m. All the variables were statistically significant and had the expected direction of correlation. The final regression model yielded a coefficient of determination, R 2, of 0.88. The spatial variations captured in this analysis are being used to guide the selection of participants for a number of Health Canada studies.
Synthesis and Crystal Structure of 3-(4-Methoxyphenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one

Synthesis of the title compound from 4-methoxyaniline was accomplished in three steps. The structure was supported by spectroscopic data and unambiguously confirmed by single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21 with unit cell dimensions α = 9.9349(8), b = 6.3377(5), c = 10.5783(10) A, β = 97.752(3)°, V = 659.97(10) A3, Z = 2.
Hydrogen Generation from Highly Activated Al–Ce Composite Materials in Pure Water

The reaction of aluminum with pure water is an eco-friendly approach to generate hydrogen. The main difficulty associated with this approach is that an oxide or hydroxide protective film around aluminum particles prohibit the hydrogen generation. In this article, a kind of highly activated Al–Ce composite material has been developed via a convenient ball milling method. Typically, Al–13 wt% Ce has a total hydrogen production of 1134 mL/g and a conversion yield of 92.42% within 60 min. The influences of the cerium concentration and ball milling time on the hydrogen production efficiency are discussed based on XPS, XRD, FESEM, and BET techniques. In addition, the hydrogen production efficiency can be improved by adding alkali chloride (NaCl or KCl) to the Al–Ce composite materials.
Geographical Characterization of Greek Olive Oils Using Rare Earth Elements Content and Supervised Chemometric Techniques

Different ANNs models [Multi-layer Perceptrons (MLPs) and Radial Basis Function (RBF)] were developed and evaluated for the discrimination of olive oils produced in four Greek regions according to their geographical origin. For this purpose, ninety-seven samples were analyzed for 10 rare earth elements (REE) by ICP-MS. Moreover, two additional supervised techniques, discriminant analysis (DA) and classification trees (CTs), were applied to the same set for the data pre-treatment and for comparison purposes. In addition, two approaches were used for models' training and evaluation: the classical random choice of samples for the learning data set and an innovative one, which used the two linear discriminant functions (LDFs) of the preceding DA to choose the most representative learning sample set. The results were very satisfactory for the new ANNs classifiers. Over-fitting phenomena were overcome and the prediction ability was 73%, as evaluated by an independent test sample set. The results are encouraging for the ANNs efficiency even in demanding data bases, as the one under consideration. [Supplementary materials are available for this article. Go to the publisher's online edition of Analytical Letters for the following free supplemental resources: Additional figures and tables. ]
Trace Detection of Explosives Vapours by Molecularly Imprinted Polymers for Security Measures

In view of the recent terror acts for example against aviation or underground transportation systems, it is obvious that the detection techniques used today for explosives are inadequate and have to be improved. In concern with national security there is need for inexpensive, rapid, highly sensitive and selective sensors. In this respect, mass-sensitive devices coated with substance specific molecularly imprinted polymers (MIPs) look promising to achieve low-cost detection devices capable of detecting gaseous explosives traces fast, sensitively and reliably. Preliminary results and possible concepts for MIP-based low-cost sensors are presented in this paper.
Synthesis and characterization of Fe‐doped LiNbO3 nanocrystals from a triple‐alkoxide method

Nanocrystals of Fe/LiNbO3 were synthesized from Li(OC2H5), Nb(OC2H5)5, and Fe(OC2H5)3 using a triple alkoxide sol–gel method with Fe‐dopings of 0.5 and 1 mol%, respectively. X‐ray diffraction proves the samples to be phase‐pure and crystalline. The size of the crystals as determined by Scherrer equation and transmission electron microscopy is below 50 nm. Iron is distributed homogeneously within the crystals as shown with energy‐dispersive X‐ray spectroscopy. Ferroelectricity is verified by piezoresponse force microscopy. Vacuum annealing enables to control the Fe2+/Fe3+‐concentration ratio from 0.1 to 0.9 with a reduction onset temperature of 200 °C.
Permeâmetro de carga decrescente associado a programa computacional para a determinação da condutividade hidráulica do solo saturado

The soil saturated hydraulic conductivity (Kθs) is a property with great variability, which requires the use of a greater number of determinations so that they can be described by the normal probability density function. Consequently, there is an increase in time and labor to obtain Kθs results if determined by conventional equipment. The use of more practical equipment and computational tools allows a faster and more accurate analysis. With this aim a falling head permeameter was built and a software for data acquisition was developed. Values of Kθs obtained with this equipment in Hapludalf samples showed less variability, as assessed by the coefficient of variation, resulting in more precise measurements. Moreover, the time of analysis was reduced by 30 %.
Microwave‐Assisted Synthesis of 1‐Methyl‐2,4,5‐trinitroimidazole

The synthesis of 1-methyl-2,4,5-trinitroimidazole (6) in good yields starting from imidazole (1) via nitrodeiodination under microwave irradiation is reported herein. The synthesized compounds were characterized by IR and NMR spectroscopy, mass spectrometry, and CHN analyses.
Biotic uptake and release of phosphorus by a wetland sediment

Currently there is considerable controversy about the role of bacteria in the direct uptake and release of phosphorus by sediments. This paper reports work aimed at testing the hypothesis that microbial uptake and release of phosphorus by sediments is an important process in wetlands and that this process is influenced by the type of organic matter in the sediment. Experiments were undertaken with a wetland sediment to which was added both a carbon source (glucose or acetate) and orthophosphate (P). The carbon sources were chosen to represent a simple available carbon source (glucose) and a fermentation product (acetate). Control experiments were also undertaken using a sterilised sediment with P added and an unsterilised sediment without added P. Under aerobic conditions, 100% of the added orthophosphate was taken up biologically by both the organic carbon-amended sediments, with 34–45% of this estimated to be microbial uptake. A smaller amount (ca. 9%) of the added phosphorus was taken up biotically by .
Copper(I) and silver(I) coordination frameworks involving extended bipyridazine bridges

1,4-(Pyridazin-4-yl)benzene (bpph), a new N-donor tetradentate ligand, was prepared by inverse electron demand cycloaddition reacting 1,4-diethynylbenzene and 1,2,4,5-tetrazine. In combination with Cu(I) and Ag(I) ions, it affords coordination framework topologies that were dominated by assembly of dinuclear metal–pyridazine “secondary building blocks” [M2(μ-pdz)2] supporting further polymeric connectivity. In structures [Cu2(bpph)(CH3CN)2{S2O6}] (1) and [Ag6(bpph)3(H2O)6{C6H4(COO)2}2]C6H4(COO)2·4H2O (8) interconnection of the dinuclear nodes occurs with anionic dithionate and isophthalate bridges, while [Ag2(bpph){C6H5CO2}2]·2H2O (7) adopts a linear chain structure incorporating disilver(I) pyridazine units and terminal benzoate anions. [Cu4(bpph)5](BF4)4·4CHCl3 (2) has a 3D supramolecular structure involving polycatenation of the 2D “bilayer” metal–organic topologies built up of five-connected dinuclear nodes. Frameworks of [Ag(bpph){NO3}]·CHCl3 (3) and [Ag(bpph){C2F5COO}] (5) exist as 2D square-grids nets supported with sets of tetra- and bidentate bipyridazine bridges, while closely related [Ag4(bpph)3{CF3COO}4]·CH3CN (4) is a 1D “ladder” polymer. The three-fold interpenetrated 3D diamondoid framework of [Ag4(bpph)3{CH3SO3}4]·2CHCl3 (6) was based upon more complicated tetranuclear nodes [Ag4(μ-pdz)4(pdz)2].
Bottom-up growth of Ag/a-Si@Ag arrays on silicon as a surface-enhanced Raman scattering substrate with high sensitivity and large-area uniformity

In this work, we demonstrated a bottom-up growth of Ag/a-Si@Ag nanosphere arrays on Si to work as a high performance SERS substrate. By a solid-state dewetting process, high density Ag nanoparticle arrays were formed on the Si substrate with large-area uniformity. With well-controlled thicknesses of a-Si and Ag outer-layer coating, the SERS properties can be optimized with the inter-particle spacing of the Ag/a-Si@Ag NSs limited to several nanometers. Based on the analysis of optical properties and SERS activities to p-Tc molecules, we concluded that the optimized SERS substrate performed with both high sensitivity and large-area uniformity. A detection limit as low as 10−14 M and an enhancement factor (EF) up to 108 were obtained. Furthermore, the wafer scale large-area uniformity and reproducibility of the SERS signal were confirmed with small standard deviation, e.g., 8% at 1076 cm−1 and 9% at 1593 cm−1. The generic approach presented here can be extended to create a new class of highly sensitive SERS sensors with large-area output, and may play an important role in device design and the corresponding diverse chemical and biological detection tasks.
Cleanup of Oily Wastewater by Froth Flotation: Effect of Microemulsion Formation

ABSTRACT This study showed that the efficiency of removal of σdichlorobenzene from water by batch froth flotation increases as changes in salinity cause the system to vary from a Winsor Type I microemulsion to a Winsor Type III microemulsion. The cationic surfactant studied is more effective than either the monosulfate or the disulfonate anionic surfactants studied. The oil flotation efficiency increasesas the initial surfactant concentration increases, as the salinity increases (causing a Winsor Type I to III transition for these systems), and as the oil/water ratio decreases.
Titanocene‐Catalysed Electron Transfer‐Mediated Opening of Epoxides

The use of epoxides as substrates for radical reactions via electron transfer is described. The discussion of the evolution of stoichiometric reagents focuses on recent developments in the field of titanocene(III) reagents. Special attention is devoted to the emergence of catalytic conditions for this useful procedure that has led to the discovery of reagent-controlled radical reactions by variations of the cyclopentadienyl ligands.