A new organic–inorganic compound, bis(4-acetylanilinium) tetrachlorocadmiate, has been synthesized and characterized by single-crystal X-ray diffraction, thermal analysis and dielectric measurements. ...The title compound crystallizes at room temperature in the orthorhombic system (Cmca space group) with the following unit cell parameters: a=19.9803(5)Å, b=15.3829(3)Å, c=13.8168(3)Å and Z=8. Display omitted
The new organic inorganic compound C8H10NO2CdCl4 crystallizes at room temperature in the orthorhombic system (CmCa space group) with the following unit cell parameters: a=19.9803(5)Å, b=15.3829(3)Å, c=13.8168(3)Å and Z=8. The atomic arrangement can be described as an alternation of organic/inorganic layers along the a direction. The organic layer is built up by one type of C8H10NO+ cation and the inorganic layer is built up by isolated and distorted tetrahedral CdCl42− anions. The TGA–DTA curves revealed two endothermic peaks. The first peak may be due to a phase transition, while the second peak corresponds to the decomposition point. Additionally analysis of the dielectric constants ε′ and ε″ versus temperature at several frequencies shows a relaxation process which could be due to disorder in the lattice.
The increasing presence of contaminants of emerging concern in wastewater and their potential environmental risks require improved monitoring and analysis methods. Direct toxicity assessment (DTA) ...using bioassays can complement chemical analysis of wastewater discharge, but traditional in vivo tests have ethical considerations and are expensive, low-throughput, and limited to apical endpoints (mortality, reproduction, development, and growth). In vitro bioassays offer an alternative approach that is cheaper, faster, and more ethical, and can provide higher sensitivity for some environmentally relevant endpoints. This study explores the potential benefits of using whole water samples of wastewater and environmental surface water instead of traditional solid phase extraction (SPE) methods for in vitro bioassays testing. Whole water samples produced a stronger response in most bioassays, likely due to the loss or alteration of contaminants during SPE sample extraction. In addition, there was no notable difference in results for most bioassays after freezing whole water samples, which allows for increased flexibility in testing timelines and cost savings. These findings highlight the potential advantages of using whole water samples in DTA and provide a framework for future research in this area.
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•Adaption of in vitro bioassays of ecologically relevant endpoints for WET.•Freezing as a way of sample preservation is generally acceptable.•Samples were compared in whole water form to traditional SPE.•Samples in whole water were up to 50× more toxic than the corresponding extract.
•Two new curcumin derivatives with excellent chemical, physical, and biological properties were synthesised.•The obtained crystals were characterized and analysed using NMR, UV–vis, FTIR, and PL ...spectra and TG/DTA thermograms.•The compounds were also screened for their anti-bacterial activity and found to exhibit activity almost the same as that of the antibiotic Ampicillin was used as a reference drug.•The derived results were highly promising and can be used as lead materials for industrial and pharmaceutical applications.
Two chemically and biologically important curcumin derivatives, namely (3E, 5E)-3, 5- bis (3-ethoxy-4-methoxybenzylidene)-1-methylpiperidine-4-one and (3E, 5E) -3, 5-bis (2, 4 -dimethoxybenzylidine) -1-methylpiperidine - 4 - one was synthesised from the mixture of 3-ethoxy-4-methoxybenzaldehyde and 1-methyl piperidone (EMPM) and 2,4-dimethoxybenzaldehyde with 1-methyl piperidone (MBMP). The resultant compounds were chemically characterised using X-ray techniques. Both the compounds were crystallised in a triclinic crystal system with space group Pī and their 3D structures were stabilised by the weak CH···O, CH···π, and π… π intermolecular interactions. The title materials were also analysed for their optical properties via NMR, UV–vis, FTIR, and PL spectra. TG and DTA thermograms of the compounds were investigated to derive melting points, thermal stability, and other associated thermal processes. Information about short contacts such as CH…π, and π…π molecular interactions was studied using Hirshfeld surfaces analysis. In vitro screening of the compounds has been performed for their antibacterial activity, which discloses their highly promising antibacterial properties against the tested microorganisms.
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This study develops the headway control framework in a fully automated road network, as we believe headway of Automated Vehicles (AVs) is another influencing factor to traffic dynamics in addition to ...conventional vehicle behaviors (e.g. route and departure time choices). Specifically, we aim to search for the optimal time headway between AVs on each link that achieves the network-wide system optimal dynamic traffic assignment (SO-DTA). To this end, the headway-dependent fundamental diagram (HFD) and headway-dependent double queue model (HDQ) are developed to model the effect of dynamic headway on roads, and a dynamic network model is built. It is rigorously proved that the minimum headway could always achieve SO-DTA, yet the optimal headway is non-unique. Motivated by these two findings, this study defines a novel concept of maximin headway, which is the largest headway that still achieves SO-DTA in the network. Mathematical properties regarding maximin headway are analyzed and an efficient solution algorithm is developed. Numerical experiments on both a small and large network verify the effectiveness of the maximin headway control framework as well as the properties of maximin headway. This study sheds light on deriving the desired solution among the non-unique solutions in SO-DTA and provides implications regarding the safety margin of AVs under SO-DTA.
•A headway-dependent double queue (HDQ) model for links.•SO-DTA can be achieved under minimum headway with proof.•Maximin headway still achieves SO-DTA with larger headway.•Maximin headway is solved analytically.
A new metal-organic NLO single crystal of 2-Aminopyridinium bishexaaqua(cobalt(II)) sulfate monohydrate (2APCS) has been obtained by the reaction of aqueous solution of 2-Aminopyridine and cobalt(II) ...sulfate heptahydrate and by room temperature slow evaporation process. Single crystal X-ray diffraction study of the grown single crystal confirms the P1¯ space group of a triclinic structure. The crystalline molecules are stabilized by elaborate OH⋯O and NH⋯O classical three dimensional hydrogen bonding network. The functional groups in the 2APCS were established by the FT-IR and Laser Raman spectroscopy. The obtained crystals were also characterized for thermal stability, dielectric, optical and nonlinear optical properties. Z-Scan technique was employed to observe the third order nonlinear optical susceptibility and was observed to be high. The optical limiting behaviour of the grown crystal is recognized mainly to nonlinear refraction.
A new organometallic NLO single crystals of 2-Aminopyridinium bishexaaqua (cobalt(II)) sulfate monohydrate was synthesized by slow evaporation method and the molecular structure was confirmed by single crystal X-ray diffraction study. From Z-scan study, nonlinear refractive index, nonlinear absorption and third order nonlinear susceptibility values were calculated. The optical limiting behaviour observed with the crystal is attributed mainly to nonlinear refraction. Display omitted
•A new metal-organic single crystals of 2-Aminopyridinium bis hexaaqua(cobalt(II)) sulfate monohydrate has been grown by slow evaporation solution growth technique.•The structure is reported for the first time in the literature.•The optical quality and thermal stability of the 2APCS crystal was studied by UV–Vis–NIR and TG/DTA.•The electrical conductivity, dielectric loss and dielectric constant have been investigated.•The grown crystal exhibited high third order optical nonlinearity which was determined by Z-Scan technique.
Summary
Oxy‐fuel (OF) combustion is considered as one of the promising carbon capture and storage technologies for reducing CO2 emissions from power plants. In the current work, the thermal behaviour ...of Estonian oil shale (EOS) and its semicoke (SC), pine saw dust, and their blends were studied comparatively under model air (21%O2/79%Ar) and OF (30%O2/70%CO2) conditions using thermogravimetric analysis. Mass spectrometry analysis was applied to monitor the evolved gases. The effect of SC and pine saw dust addition on different combustion stages was analysed using kinetic analysis methods. In addition, different co‐firing cases were simulated using the ASPEN PLUS V8.6 (APV86) software tool to evaluate the effects of blending EOS with different biomass fuels of low and high moisture contents. The specific boiler temperatures of each simulated case with the same adjusted thermal fuel input were calculated while applying the operation conditions of air and OF combustion. According to the experiment and process simulation results, the low heating value and high carbonate content of SC brings along endothermic decomposition of carbonates, which negatively affects the heat balance during the conventional co‐combustion of EOS with SC. Instead, firing of EOS with SC and biomass in OF process can be an effective solution to reduce the environmental impact in terms of the reduction of CO2 emissions and ash. Furthermore, the sensible heat from SC can positively affect the energy balance of the system as the endothermic effect of decomposition of CaCO3 (for both EOS and SC) can be avoided in OF combustion.
Firing of oil shale with semicoke and biomass in oxy‐fuel combustion process can give an effective solution for the use of the heating value of semicoke. Furthermore, multifuel combustion with the optimum ratios can be a promising alternative to meet future emission targets and reduce the environmental impact in terms of the reduction of CO2 and waste ash emissions from oil shale processing and oil shale‐based power sector.
•Novel 3-methylbenzylammonium trioxonitrate compound was synthesized at room temperature.•Optimized geometry and vibrational studies were computed by using B3LYP/6-311++G(d,p) theory.•The atomic ...arrangement of the synthesized compound shows two-dimensional network.•Determination of band gap energy using the energy difference between HOMO and LUMO (Eg = 5.34 eV).
This paper shall address the synthesis and characterization of the novel non-centrosymmetric inorganic-organic hybrid material 3-methylbenzylammonium nitrate with general chemical formula C8H12N(NO3) (3MBAN), this compound has been synthesized via slow evaporation method at room temperature and it is structurally characterized by single-crystal X-ray diffraction, crystallized to the monoclinic system with space group Cc and the following parameters 7.574(3), 29.494(10), 5.1894(15), β = 128.669(11)°, Z = 4, V = 905.1(5) Å3 at 150 K and its crystal structure was determined and refined down to R = 0.057 and wR = 0.140. The monoprotonated 3-methylbenzylammonium cations are linked to the trigonal (NO3−) anions by multiple bifurcated N—H…(O,O) and weak C—H…O hydrogen bonds forming R44(12) and R32(6) motifs. The paper discusses also quantitatively the intermolecular interactions using the Hirshfeld surfaces (HS) associated with 2D fingerprint plots. The optimized molecular structure and the vibrational spectra were calculated by the density functional theory (DFT) method using the B3LYP function. Good consistency is found between the calculated results and the experimental structure; IR spectra confirmed the presence of the principal bands assigned to the internal modes of the organic cation and nitrate anion. Topological approaches such as reduced density gradient (RDG), atoms in molecules (AIM), electron localization function (ELF), endorse the occurrence of intermolecular hydrogen bonds that are responsible for the stabilization of the title compound leading to high nonlinear optical (NLO) activity. The analyses of HOMO and LUMO have been used to explain the charge transfer within the molecule. The thermal analysis of the title compound indicates its melting at 395 K follows a rapid decomposition appearing around 495 K. Finally Optical absorption reveals an important band gap energy indicating stability of the title compound.
Data on the thermal stability of energetic materials such as nitrocellulose was required in order to obtain safety information for handling, storage and use. In the present study, the thermal ...stability of four nitrocellulose samples containing various amount of nitrate groups was determined by differential scanning calorimetery (DSC) and simultaneous thermogravimetery-differential thermal analysis (TG-DTA) techniques. The results of TG analysis revealed that the main thermal degradation for the nitrocellulose occurs in the temperature ranges of 192–209
°C. On the other hand, the TG-DTA analysis of compounds indicates that nitrate content of nitrocellulose could has affect on its thermal stability and its decomposition temperature decrease by increasing its nitrogen percent. The influence of the heating rate (5, 10, 15 and 20
°C/min) on the DSC behaviour of the nitrocellulose was verified. The results showed that, as the heating rate was increased, decomposition temperature of the compound was increased. Also, the kinetic parameters such as activation energy and frequency factor for the compound was obtained from the DSC data by non-isothermal methods proposed by ASTM E696 and Ozawa.
Solid biofuels derived from microalgae represent a low-cost, high-volume bioproduct opportunity with excellent CO2 biofixation capability, contributing significantly to the attainment of net zero. ...Oxidative torrefaction also offers a more economical pretreatment to upgrade its solid fuel properties. This study investigates the thermo-kinetics aspect of oxidative torrefaction of microalgae with varying O2 concentrations using thermogravimetric and differential thermal analysis (TGA-DTA). Isoconversional kinetic modeling is applied to mass-loss data and shows average activation energies of 172.57, 174.68, 199.42, and 209.03 kJ‧mol−1 at 0, 3, 12, and 21 % O2 concentrations, respectively. The effect of O2, especially at 12 vol%, significantly reduces the calculated activation energy at lower conversion. DTA also reveals lower heat flow values under oxidative than inert torrefaction. Thermo-kinetics data are then utilized to conduct machine learning approaches. Regression via artificial neural networks shows that the prediction of conversion and heat flow values are predominantly dictated by the temperature, followed by heating rate and O2 concentration. Finally, classification using the k-nearest neighbors algorithm highlights the effects of factors at specific ranges of conversion and heat flow responses. The O2 concentration is significant only at early conversion (X<0.1) and contributes to generally lower heat flow values.
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•Microalgae oxidative torrefaction can be reduced to a one-step reaction mechanism.•12 vol% O2 has similar activation energy as inert torrefaction at low conversion.•Lower heat flow values are associated with higher O2 concentrations until 12 %.•Performance accuracy of above 99 % were attained for machine learning tasks.•Artificial neural network and k-nearest neighbors quantified the effects of factors.
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