Simulation Investigation of Bulk and Surface Properties of Liquid Benzonitrile: Ring Stacking  Assessment and Deconvolution

This manuscript is devoted to classical molecular dynamics (MD) simulation studies of the bulk and surface properties of liquid benzonitrile (BZN) in the temperature range of 293-323K. The content and the simulation-analysis are inspired by our recent ab initio calculation on benzonitrile, whereas present results are to expand and develop macroscopic documentation involving data verification. We investigate the molecular stacking that involves phenyl ring, which is notably absent in the counterpart acetonitrile solvent. MD simulations of the bulk liquid unravel the hydrogen bond (C≡N⋯H) formation and strength, in the order of ortho-H >> meta-H ~>para-H. The possibility for ortho-H’s to get involved in the formation of two bonds simultaneously confirms each having - and -bonding features. The singularity centered at about 313 K found in the trend of the simulated temperature-dependent viscosity and diffusion coefficient of liquid BZN goes alongside the reported experiment, and the phenomenon may root from a change in the internal frictional motion of the molecular cluster in stacking modes. Accordingly, we used vast efforts for analysis particularly based on the deconvolution of the corresponding complex correlation functions. Specific angle-dependent correlation functions led to the recognition of the stacking molecules and their strict orientational character by utilizing relative molecular twist angles. Recognition of the strict orientational character of the stacking molecules, as a clue to the singularity in the viscosity trend, will be discussed based on specific angle-dependent correlation functions.

Enrichment of Components at Vapour-Liquid Interfaces: A Study by Molecular Simulation and Density Gradient Theory

In separation processes not only thermodynamic bulk but also interfacial properties play a crucial role. Inclassical theory, a vapour-liquid interface is a two-dimensional object. In reality it is a region in whichproperties change over a few nanometres and the density changes continuously from its liquid bulk to its gasbulk value. Many mixtures show unexpected effects in that transition region. While the total density changesmonotonously from the bulk vapour to the bulk liquid, this does not hold for the molarities of the components.The molarities of the light boiling component can have a distinct maximum at the interface. That maximumwould be an insurmountable obstacle to mass transfer according to Fickian theory. Even if that argument isnot adopted, it shows that there is good reason to believe that the maximum may affect mass transfer and,hence, fluid separation processes like absorption or distillation. Unfortunately, there are currently noexperimental methods that can be used for direct studies of density profiles in such interfacial regions. Butsuch data can be obtained with theoretical methods, namely with molecular dynamics simulations (MD) aswell as with density gradient theory (DGT) or with density functional theory (DFT) combined with an equationof state (EOS).Studies from our group on the vapour-liquid interface of several real mixtures and a model fluid using thesemethods yield consistent results and reveal an important enrichment in some cases. Strong enrichment isfound at vapour-liquid interfaces in the systems in which one of the components is supercritical. These resultsindicate that mixtures, which are typical for absorption processes usually show an important enrichment,whereas this is not the case for mixtures that are typically separated by distillation. Possible consequences ofthis finding for the modelling of these separation processes are discussed.

Surveying a Swarm: Experimental Techniques to Establish and Examine Bacterial Collective Motion

The survival and successful spread of many bacterial species hinges on their mode of motility. One of the most distinct of these is swarming, a collective form of motility where a dense consortium of bacteria employ flagella to propel themselves across a solid surface. Surface environments pose unique challenges, derived from higher surface friction/tension and insufficient hydration. Bacteria have adapted by deploying an array of mechanisms to overcome these challenges. Beyond allowing bacteria to colonize new terrain in the absence of bulk liquid, swarming also bestows faster speeds and enhanced antibiotic resistance to the collective. These crucial attributes contribute to the dissemination, and in some cases pathogenicity, of an array of bacteria. This mini-review highlights; 1) aspects of swarming motility that differentiates it from other methods of bacterial locomotion. 2) Facilitatory mechanisms deployed by diverse bacteria to overcome different surface challenges. 3) The (often difficult) approaches required to cultivate genuine swarmers. 4) The methods available to observe and assess the various facets of this collective motion, as well as the features exhibited by the population as a whole.

Effects of process factors on performances of liquid membrane-based transfer of indole-3-acetic acid

The paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10–4–10–3 kmol/m3), of TOA in the membrane phase, cL,M0 (10–2 and 10–1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10–2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex = 0.02–1 × 10–4 kmol/m3, cIAA,Sf,ex = 0.22–2.58 × 10–3 kmol/m3, EF,ex = 90.0–97.9%, KD,ex = 9.0–46.6, and ER,ex = 66.5–94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.82–11.5 × 10–7 m/s) and extraction constant (1033.9–1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

Experimental and Analytical Investigation for Reduction in Cost of Polyurethane Waste Disposal at Adani Hazira Port Pvt. Ltd.

Adani hazira Port handles all types of cargo including bulk, break-bulk, bulk liquid chemicals, petroleum products & edible oil, containers, automotive and crude. project includes to investigation and estimation of reduction in cost of pig foam by experimental data collection and analysis of the pig foam for manufacturing of foam squeezing machine. and study the property of same.Adani is facing issue of more use of polyurethane foam, high disposal cost of polyurethane, higher time of reutilization. pipeline clearance is done with pigging operation. work plan is to Reduction in cost of foam pig utilization per annum, reduction in cost of polyurethane foam disposal. Keyword: 1. Project Management , 2. Waste Management, 3. Pipeline management , 4. Mechanical Engineering.

Transport and Separation of the Silver Ion with n–decanol Liquid Membranes Based on 10–undecylenic Acid, 10–undecen–1–ol and Magnetic Nanoparticles

This paper presents a transport and recovery of silver ions through bulk liquid membranes based on n–decanol using as carriers 10–undecylenic acid and 10–undecylenyl alcohol. The transport of silver ions across membranes has been studied in the presence of two types of magnetic oxide nanoparticles obtained by the electrochemical method with iron electrodes in the electrolyte with and without silver ions, which act as promoters of turbulence in the membrane. Separation of silver ions by bulk liquid membranes using 10–undecylenic acid and 10–undecylenyl alcohol as carriers were performed by comparison with lead ions. The configuration of the separation module has been specially designed for the chosen separation process. Convective-generating magnetic nanoparticles were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy dispersive spectroscopy analysis (EDAX), Fourier Transform InfraRed (FTIR) spectroscopy, thermal gravimetric analysis (TGA), differential scanning calorimetry and magnetization. The process performance (flux and selectivity) was tested were tested for silver ion transport and separation through n–decanol liquid membranes with selected carriers. Under the conditions of the optimized experimental results (pH = 7 of the source phase, pH = 1 of the receiving phase, flow rate of 30 mL/min for the source phase and 9 mL/min for the receiving phase, 150 rot/min agitation of magnetic nanoparticles) separation efficiencies of silver ions of over 90% were obtained for the transport of undecenoic acid and about 80% for undecylenyl alcohol.

Dynamics of macro- and micro-bubbles induced by nanosecond discharge in liquid water

Gaseous micro-bubbles dispersed in liquid water represent perturbations of the homogeneity of the liquid and influence the onset of electrical discharge in the bulk liquid. In this study, we systematically examined shadowgraph images to analyse the gaseous structures occurring in response to nanosecond micro-discharges produced in deionised water. The images revealed the dynamics of resolved bubbles and unresolved sub-micrometric structures starting from nanoseconds after the onset of discharge. We provide absolute counts and the radii distributions of micro-bubbles that occur near the anode needle and show how this depends on the amplitude and repetition frequency of the applied high-voltage pulses, when the latter varies between 0.1 and 100 Hz. A systematic statistical analysis showed that the probability of producing bubble-assisted nanosecond discharge in the liquid phase rapidly increases with the discharge repetition rate (>0.5 Hz). Although the cavitation bubble formed around the anode disintegrates and disappears from the anode region within the first millisecond, the sub-micrometric structures remain for tens of milliseconds, and fragmented micro-bubbles survive even for hundreds of milliseconds. Our findings impose strict limitations on the experimental setups used to investigate the mechanisms of direct discharge in liquid water.

Effect of voltage polarity and supply frequency on properties of plasma contacting liquid electrode and gold nanoparticle synthesis

Plasma contacting with liquid provides many charged particles and reactive species into the liquid. The difficulty in controlling or selecting each specific species has significantly limited its applications in industry. Here, we present a study on using voltage polarity to regulate the type of charged particles absorbing from plasma into liquid. Detailed understanding of the processes at the plasma-liquid interface, electrolysis due to switching in voltage polarity was investigated via a visual pH observation, measuring the concentration of H2O2 and solvated electrons. The results indicated that changing in voltage polarity strongly affects the plasma properties, chemical properties, and electrolysis process in liquid, and further in the types of reducing species for gold nanoparticle synthesis. The results also showed using a suitable frequency could improve the efficiency of absorption of H2O2from plasma into the bulk liquid and the yield in the production of gold nanoparticles. The results provide a way to select desired species from plasma into the liquid for a distinct purpose and accompanying other properties in the system of plasma contacting with liquid.