Performance of Electropun Polyacrylonitrile Nanofibrous Phases, Shown for the Separation of Water-Soluble Food Dyes via UTLC-Vis-ESI-MS

Research in the miniaturization of planar chromatography led to various approaches in manufacturing ultrathin-layer chromatography (UTLC) layers of reduced thickness (<50 µm) along with smaller instrumentation, as targeted in Office Chromatography. This novel concept merges 3D print & media technologies with miniaturized planar chromatography to realize an all-in-one instrument, in which all steps of UTLC are automated and integrated in the same tiny device. In this context, the development of electrospun polyacrylonitrile (PAN) nanofiber phases was investigated as well as its performance. A nanofibrous stationary phase with fiber diameters of 150–225 nm and a thickness of ca. 25 µm was manufactured. Mixtures of water-soluble food dyes were printed on it using a modified office printer, and successfully separated to illustrate the capabilities of such UTLC media. The separation took 8 min for 30 mm and was faster (up to a factor of 2) than on particulate layers. The mean hRF values ranging from 25 to 90 for the five food dyes were well spread over the migration distance, with an overall reproducibility of 7% (mean %RSD over 5 different plates for 5 dyes). The individual mean plate numbers over 5 plates ranged between 8286 and 22,885 (mean of 11,722 over all 5 dyes). The single mean resolutions RS were between 1.7 and 6.5 (for the 5 food dyes over 5 plates), with highly satisfying reproducibilities (0.3 as mean deviation of RS). Using videodensitometry, different amounts separated in parallel led to reliable linear calibrations for each dye (sdv of 3.1–9.1% for peak heights and 2.4–9.3% for peak areas). Coupling to mass spectrometry via an elution head-based interface was successfully demonstrated for such ultrathin layers, showing several advantages such as a reduced cleaning process and a minimum zone distance. All these results underline the potential of electrospun nanofibrous phases to succeed as affordable stationary phase for quantitative UTLC

Lopsided galaxies: the case of NGC 891

It has been known for a long time that a large fraction of disc galaxies are lopsided. We simulate three different mechanisms that can induce lopsidedness: flyby interactions, gas accretion from cosmological filaments and ram pressure from the intergalactic medium. Comparing the morphologies, HI spectrum, kinematics and m=1 Fourier components, we find that all of these mechanisms can induce lopsidedness in galaxies, although in different degrees and with observable consequences. The timescale over which lopsidedness persists suggests that flybys can contribute to ~20 per cent of lopsided galaxies. We focus our detailed comparison on the case of NGC 891, a lopsided, edge-on galaxy with a nearby companion (UGC 1807). We find that the main properties of NGC 891 (morphology, HI spectrum, rotation curve, existence of a gaseous filament pointing towards UGC 1807) favour a flyby event for the origin of lopsidedness in this galaxy.Comment: 12 pages, 12 figures, MNRAS, accepte

Response of Green Gram (Vigna Radiata (L.))Wilczek to Inter Row Spacing and Phosphorus under Semi-arid Conditions of Eritrea

Green gram (Vigna radiata (L.) wilczek,) commonly known as moong or mung bean or golden gram was introduced to Eritrea as a pulse crop by Ministry of Agriculture at its National Agricultural Research Institute (NARI) in collaboration with Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA) in 2012. But its agronomic practices for semi-arid conditions of Eritrea are not yet standardised. Therefore, to find the optimum inter row spacing and phosphorus dose for its higher productivity, a field experiment was conducted at the experimental farm of Hamelmalo Agricultural College, Keren, Eritrea during summer 2015 and 2016. The experiment was conducted in randomised complete block design (RCBD) with 12 treatment combinations of two factors consisting of four inter row spacing (Broadcast, 18 cm, 30 cm, and 45 cm) and three phosphorus levels (0, 20 and 40 kg P2O5 ha-1) each replicated thrice. The results of the study revealed that sowing of K-26 bold seeded variety either by broadcast method or at 18 cm inter row spacing at10 cm plant to plant spacing fertilized with 40 kg P2O5 ha-1 through DAP fertilizer drilled at the time of sowing proved significantly superior to increase growth, yield attributes and seed yield of green gram

Evaluation of Germplasm of Pearl Millet (Penissetum glaucum L.) for Agronomic, Physiological and Biochemical Traits under Semi-arid Conditions of Hamelmalo

A field experiment was conducted at the experimental farm of Hamelmalo Agricultural College during summer 2017, to evaluate the agronomic, physiological, and biochemical performance of the collected Eritrean germplasm of pearl millet. A total of 16 accessions were tested, out of which 2 were improved varieties included as a check. The experiment was laid out in 4 x 4 Simple Lattice Design with Randomized Block using 4 replications with a gross plot size of 3.0 m x 1.2 m, row to row spacing of 75 cm and plant to plant spacing of 30 cm. The data collected were Agronomic parameters (growth, development, yield, and yield contributing characters); Physiological parameters (Relative water content and Water Use Efficiency); and Biochemical parameters (crude fat, crude fiber, protein content, TSS, and ash content). The data were analyzed using GENSTAT software and correlation analysis was worked to see the positive and negative contribution of agronomic, physiological, and biochemical attributes. The results of the study showed that Bariyay908 and Kona being statistically at par with Bariyay 910, Hagaz, Zibedi, Shleti, Delkata, Tokroray, and Kunama produced significantly higher grain yield. However, among these Baryay908 because of its superior agronomic characteristics, lower incidence of downy mildew, relatively higher water use efficiency and higher crude protein content were found to be comparatively superior to the check improved varieties Kona and Hagaz. Grain yield has shown a positive and significant correlation with harvest index, number of seeds per panicle, panicle length, leaf area and water use efficiency. These promising accessions need to be further tested for future breeding programs to develop varieties higher in productivity and resistant to downy mildew under semiarid conditions of Eritrea

Evaluation of Sorghum (Sorghum bicolor) Landraces for Drought Tolerance Using Morphological and Yield Characters under Rainfed Conditions of Sub Region Hagaz, Eritrea

Sorghum is an important food crop in Eritrea where it is widely grown in the mid and low lands, of semi-arid regions. Eritrea being the center of origin of sorghum, a large variability exist in its landraces being grown by the farmers since generations. In order to improve the productivity of sorghum under moisture stress conditions, it is imperative to evaluate these landraces for drought tolerant characteristics and their use for further crop improvement programmes. Therefore, a field study was conducted in a randomized complete block design with three replications to estimate the extent of genetic variability of 20 sorghum genotypes for moisture stress tolerance using various morphological, phenological, yield and yield related parameters under rainfed conditions at Hagaz Research Station. Significant difference was observed for almost all the characters in the individual analysis of variance suggesting that these sorghum accessions were highly variable. Accessions EG 537, EG 1257, EG 849, EG 791, EG 783 and EG 813 showed promising results for post flowering drought tolerance, grain yield and stay green traits. Higher PCV and GCV were also obtained in parameters like plant height, leaf area, biomass, peduncle exertion, panicle length, and grain yield and panicle weight. The genotypes also exhibited varying degrees of heritability estimates. Characters such as plant height, panicle length, days to flowering and maturity showed higher heritability. Cluster analysis revealed that sorghum landraces were grouped on the basis of their morphological traits and geographical sites. 77.3% of the total variation of sorghum landraces was contributed by the first four principal components analysis having Eigen value > 1. Overall, the current study confirmed that EG 537, EG 849, EG 1257, EG 791, and EG 813 are drought tolerant sorghum landraces during post flowering stage

Effect of Dates and Methods of Sowing with and without Hydropriming on Growth, Phenology and Yield of Sorghum under Semi Arid Conditions of Eritrea

A study was carried out at the research farm of Hamelmalo Agricultural College during summer 2015 to study the effect of dates and methods of sowing with and without hydro-priming on growth, development and yield of sorghum. The experiment consisted of 2 factors- three dates of sowing viz. D0 (Sowing before the onset of first summer rain, June 30), D1 (Sowing with the onset of first summer rains, July 7) and D2 (Sowing after the onset of summer rains, July 14) and three methods of sowing viz. SP (Direct sowing with hydro seed priming), TR (Transplanting) and DS (Direct sowing without hydro seed priming). The experiment was conducted in split plot design with 4 replications by keeping dates of sowing in the main plots and methods of sowing in the sub plots. The data on growth parameters, crop phenology, yield components and yield were recorded. The data were analysed using GENSTAT software and inferences were drawn by using LSD at 5% level of significance. Sowing methods significantly affected leaf area and leaf area index but sowing dates and their interaction with sowing methods did not show significant difference. Stand count, plant height, phenological parameters, thousand grain weight, grain and biomass yield were significantly affected by the sowing dates and methods but no significant difference in their interaction on all the parameters except in stand count and phenological parameters. Sowing before the onset of first summer rains (D0) resulted in significantly highest grain yield. Among the sowing methods, transplanting resulted in significantly higher grain yield seconded by direct sowing with hydro seed priming. Transplanting is less profitable and practicable as it is more laborious and difficult to apply in larger areas

Spatial and Kinematical Lopsidedness of Atomic Hydrogen in the Ursa Major Group of Galaxies

We have carried out the harmonic analysis of the atomic hydrogen (HI) surface density maps and the velocity fields for 11 galaxies belonging to the Ursa Major group, over a radial range of 4-6 disc scalelengths in each galaxy. This analysis gives the radial variation of spatial lopsidedness, quantified by the Fourier amplitude A$_1$ of the m=1 component normalised to the average value. The kinematical analysis gives a value for the elongation of the potential to be $\sim 10$. The mean amplitude of spatial lopsidedness is found to be $\sim 0.14$ in the inner disc, similar to the field galaxies, and is smaller by a factor of $\sim 2$ compared to the Eridanus group galaxies. It is also shown that the the average value of A$_1$ does not increase with the Hubble type, contrary to what is seen in field galaxies. We argue that the physical origin of lopsidedness in the Ursa Major group of galaxies is tidal interactions, albeit weaker and less frequent than in Eridanus. Thus systematic studies of lopsidedness in groups of galaxies can provide dynamical clues regarding the interactions and evolution of galaxies in a group environment.Comment: 12 pages, 7 figures, 3 tables. Accepted for publication by MNRA

Optical band gap of cross-linked, curved, and radical polyaromatic hydrocarbons.

In this work, the optical band gaps of polycyclic aromatic hydrocarbons (PAHs) crosslinked via an aliphatic bond, curved via pentagon integration and with radical character were computed using density functional theory. A variety of different functionals were benchmarked against optical band gaps (OBGs) measured by ultraviolet-visible spectroscopy with HSE06 being most accurate with a percentage error of 6% for a moderate basis set. Pericondensed aromatics with different symmetries were calculated with this improved functional providing new scaling relationships for the OBG versus size. Further calculations showed crosslinks cause a small decrease in the OBG of the monomers which saturates after 3-4 crosslinks. Curvature in PAHs was shown to increase the optical band gap due to the resulting change in hybridisation of the system, but this increase saturated at larger sizes. The increase in OBG between a flat PAH and a strained curved one was shown to be equivalent to a difference of several rings in size for pericondensed aromatic systems. The effect of σ-radicals on the optical band gap was also shown to be negligible, however, π-radicals were found to decrease the band gap by ∼0.5 eV. These findings have applications in understanding the molecular species involved in soot formation

An Ontology and Semantic Web Service for Quantum Chemistry Calculations.

The purpose of this article is to present an ontology, termed OntoCompChem, for quantum chemistry calculations as performed by the Gaussian quantum chemistry software, as well as a semantic web service named MolHub. The OntoCompChem ontology has been developed based on the semantics of concepts specified in the CompChem convention of Chemical Markup Language (CML) and by extending the Gainesville Core (GNVC) ontology. MolHub is developed in order to establish semantic interoperability between different tools used in quantum chemistry and thermochemistry calculations, and as such is integrated into the J-Park Simulator (JPS)-a multidomain interactive simulation platform and expert system. It uses the OntoCompChem ontology and implements a formal language based on propositional logic as a part of its query engine, which verifies satisfiability through reasoning. This paper also presents a NASA polynomial use-case scenario to demonstrate semantic interoperability between Gaussian and a tool for thermodynamic data calculations within MolHub.This project is supported by the National Research Foundation (NRF), Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme, and by the Alexander von Humboldt foundation

Predicting Power Conversion Efficiency of Organic Photovoltaics: Models and Data Analysis.

Funder: Cambridge TrustFunder: National Research Foundation SingaporeFunder: Alexander von Humboldt-StiftungFunder: China Scholarship CouncilIn this paper, the ability of three selected machine learning neural and baseline models in predicting the power conversion efficiency (PCE) of organic photovoltaics (OPVs) using molecular structure information as an input is assessed. The bidirectional long short-term memory (gFSI/BiLSTM), attentive fingerprints (attentive FP), and simple graph neural networks (simple GNN) as well as baseline support vector regression (SVR), random forests (RF), and high-dimensional model representation (HDMR) methods are trained to both the large and computational Harvard clean energy project database (CEPDB) and the much smaller experimental Harvard organic photovoltaic 15 dataset (HOPV15). It was found that the neural-based models generally performed better on the computational dataset with the attentive FP model reaching a state-of-the-art performance with the test set mean squared error of 0.071. The experimental dataset proved much harder to fit, with all of the models exhibiting a rather poor performance. Contrary to the computational dataset, the baseline models were found to perform better than the neural models. To improve the ability of machine learning models to predict PCEs for OPVs, either better computational results that correlate well with experiments or more experimental data at well-controlled conditions are likely required