Development and validation of consensus machine learning-based models for the prediction of novel small molecules as potential anti-tubercular agents

Molecular Diversity - Tuberculosis (TB) is an infectious disease and the leading cause of death globally. The rapidly emerging cases of drug resistance among pathogenic mycobacteria have been a...     

Experimental study on novel phase change composites for thermal energy storage

Journal of Thermal Analysis and Calorimetry - In this study, beeswax is studied as a phase change material (PCM) to store heat due to its high latent heat. The disadvantages of using beeswax were...     

Fine‐Tuning of Lewis Acidity: The Case of Borenium Hydride Complexes Derived from Bis(phosphinimino)amide Boron Precursors

Reactions of bis(phosphinimino)amines LH and L′H with Me₂S ? BH₂Cl afforded chloroborane complexes LBHCl ( 1 ) and L′BHCl ( 2 ), and the reaction of L′H with BH₃ ? Me₂S gave a dihydridoborane complex L′BH₂ ( 3 ) (LH=[{(2,4,6‐Me₃C₆H₂N)P(Ph₂)}₂N]H and L′H=[{(2,6‐iPr₂C₆H₃N)P(Ph₂)}₂N]H). Furthermore, abstraction of a hydride ion from L′BH₂ ( 3 ) and LBH₂ ( 4 ) mediated by Lewis acid B(C₆F₅)₃ or the weakly coordinating ion pair [Ph₃C][B(C₆F₅)₄] smoothly yielded a series of borenium hydride cations: [L′BH]⁺[HB(C₆F₅)₃]^? ( 5 ), [L′BH]⁺[B(C₆F₅)₄]^? ( 6 ), [LBH]⁺[HB(C₆F₅)₃]^? ( 7 ), and [LBH]⁺[B(C₆F₅)₄]^? ( 8 ). Synthesis of a chloroborenium species [LBCl]⁺[BCl₄]^? ( 9 ) without involvement of a weakly coordinating anion was also demonstrated from a reaction of LBH₂ ( 4 ) with three equivalents of BCl₃. It is clear from this study that the sterically bulky strong donor bis(phosphinimino)amide ligand plays a crucial role in facilitating the synthesis and stabilization of these three‐coordinated cationic species of boron. Therefore, the present synthetic approach is not dependent on the requirement of weakly coordinating anions; even simple BCl₄^? can act as a counteranion with borenium cations. The high Lewis acidity of the boron atom in complex 8 enables the formation of an adduct with 4‐dimethylaminopyridine (DMAP), [LBH ? (DMAP)]⁺[B(C₆F₅)₄]^? ( 10 ). The solid‐state structures of complexes 1 , 5 , and 9 were investigated by means of single‐crystal X‐ray structural analysis.     

Effect of cost-free energy storage material and saline water depth on the performance of square pyramid solar still: a mathematical and experimental study

Journal of Thermal Analysis and Calorimetry - Low productivity of single-slope solar still is the main barrier for its worldwide usability. An attempt has been conducted to enhance the distillate...     

Dye-dependent studies on droplet pattern and electro-optic behaviour of polymer dispersed liquid crystal

In order to study the droplet pattern and electro-optic (EO) behaviour of polymer dispersed liquid crystal (PDLC) with the addition of dye, dichroic polymer dispersed liquid crystal (DPDLC) films were prepared using a nematic liquid crystal (NLC), photo-curable polymer (NOA 65) and anthraquinone blue dichroic dye (B2), in equal ratio (1:1) of polymer and liquid crystal (LC) by polymerisation induced phase separation (PIPS) technique. Dichroic dye was taken in different concentration (wt./wt. ratio) as 0.0625%, 0.125%, 0.25%, 0.5% and 1% of the LC mixture in DPDLC films. Initially, in an open circuit when there is no proviso for external electric field (0 V), LC droplets in polymer matrix exhibited bipolar pattern, though on closing the circuit with the increase of electric field pattern of droplets starts changing, LC molecules align along the direction of applied electric field and aligned completely relatively at higher field (30 V), which illustrate vertical radial pattern. Further, results show that the DPDLC film containing 0.0625% dye concentration with consistent average droplet size ~4.30 μm, exhibits the best transmission at lower operating voltage.     

Effect of seasonal variation on dust samples of a winter fog affected urban environment of India,South East Asia

Physical and chemical characteristics of leaf dust (LD) samples, collected between 2011 and 2013, of a severely winter fog affected and polluted urban environment (Allahabad, India) of Indo-Gangetic plain are presented in this study. The weather changes in the study area are grouped into three effective annual seasonal periods – winter fog, pre-monsoon and post-monsoon. The pronounced impact of seasonal variations is observed in LD characteristics, as ~46% of the winter fog period samples ranges in size between 2.5 and 20 µm with high magnetic susceptibility (up to 938.22 × 10^?8 m³ kg^?1). In comparison, 35% of the LD from pre-monsoon period occurs in the size range of 100–300 µm with low magnetic susceptibility (up to 43.29 × 10^?8 m³ kg^?1). The fractal analysis involving submicroscopic clast dimension of LD also reveals a seasonal influence. The toxic metals (Pb, Zn, Cd, Cr and Ni) in LD belonging to winter fog and post-monsoon periods increase in comparison to samples from pre-monsoon time. Multivariate statistical analysis of trace element data suggests that the LD collected from winter fog and post-monsoon periods originate predominantly from anthropogenic source, whereas those collected during pre-monsoon owe their origin to crustal and anthropogenic sources, mainly. The present study has demonstrated the role of seasonal variation in controlling the physical and chemical properties of particulate matter based on multiple parameter analyses, and the derivation of the dust load from a mixed source (upper continental crust, anthropogenic and vehicular) for the study area for the first time.     

Ionic conductivity enhancement of PVA: carboxymethyl cellulose poly-blend electrolyte films through the doping of NaI salt

Cellulose - In this paper, we report the effect of doping sodium iodide (NaI) salt into a polymer blend matrix of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Solution...     

Thermal studies of hypervalent iodine reagents

The use of unconventional synthesis methods in the formation of CaO·2Al₂O₃ (CA₂) is justified because it reduces the formation temperature of the compound. CA₂ is formed by classical method at temperatures above 1,400 °C. The polymeric precursor method allows a significant temperature decrease in CA₂ synthesis reaching temperatures of 1,000 °C. This paper deals with CA₂ synthesis by “citrate” method which is often presented as Pechini method, starting from a mixture of citric acid, ethylene glycol and calcium, and aluminum nitrates. A method based on the formation of a polymeric precursor was also used, starting from a mixture of acrylic acid and nitrates of calcium and aluminum. The results showed a net difference in favor of samples obtained from acrylic acid, which by annealing at 800 °C for 1 h, contain pure CA₂. The samples obtained from citric acid, after annealing at 800 °C are amorphous. After annealing at 900 °C in all samples CA₂ is single phase.     

Nanocomposite blend gel polymer electrolyte for proton battery application

A proton-conducting nanocomposite gel polymer electrolyte (GPE) system, [35{(25 poly(methylmethacrylate) (PMMA) + 75 poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP))?+?xSiO₂}?+?65{1 M NH₄SCN in ethylene carbonate (EC) + propylene carbonate (PC)}], where x?=?0, 1, 2, 4, 6, 8, 10, and 12, has been reported. The free standing films of the gel electrolyte are obtained by solution cast technique. Films exhibit an amorphous and porous structure as observed from X-ray diffractometry (XRD) and scanning electron microscopy (SEM) studies. Fourier transform infrared spectrophotometry (FTIR) studies indicate ion–filler–polymer interactions in the nanocomposite blend GPE. The room temperature ionic conductivity of the gel electrolyte has been measured with different silica concentrations. The maximum ionic conductivity at room temperature has been observed as 4.3?×?10^?3?S?cm^?1 with 2 wt.% of SiO₂ dispersion. The temperature dependence of ionic conductivity shows a typical Vogel-Tamman-Fulcher (VTF) behavior. The electrochemical potential window of the nanocomposite GPE film has been observed between ?1.6 V and 1.6 V. The optimized composition of the gel electrolyte has been used to fabricate a proton battery with Zn/ZnSO₄·7H₂O anode and PbO₂/V₂O₅ cathode. The open circuit voltage (OCV) of the battery has been obtained as 1.55 V. The highest energy density of the cell has been obtained as 6.11 Wh?kg^?1 for low current drain. The battery shows rechargeability up to 3 cycles and thereafter, its discharge capacity fades away substantially.