VAPOR-LIQUID EQUILIBRIA OF TOLUENE + n-BUTANOL AND TOLUENE + n-BUTANOL + CALCIUM CHLORIDE AT 94.0kPa

Vapor-liquid equilibrium data of toluene + n-butanol and toluene+ n-butanol + CaCl₂ (at saturation) were measured at a pressure of 94.0 kPa, using a modified Malanowski equilibrium still. The salt investigated in this work, i.e., CaCl₂, exhibits a slight salting-out effect on toluene. The experimental results of the salt-free binary were compared with those obtained from NRTL, ASOG, and UNIFAC models. The latter two models predicted the bubble-point temperatures within 0.5 K (as a root mean square deviation, RMSD) whereas the NRTL model, which was employed to establish thermodynamic consistency by directly fitting the experimental data, correlated the bubble-point temperatures with an RMSD of 0.2 K. On the other hand, the experimental data of toluene+n-butanol+CaCl₂ were compared with those predicted by the NRTL-Tan model for the effect of the electrolyte. This model predicted the bubble-point temperatures with an RMSD of 0.5 K. Calcium chloride has been shown not to have a sensible effect on the azeotropic composition.     

Electrical and optical measurements in the early hydrogen discharge of GLAST-III

This work presents the first electrical and optical measurements of the initial phase of hydrogen discharge in the upgraded spherical tokamak GLAST-III, initiated with electron cyclotron heating (ECH). Diagnostic measurements provide insights into expected and unexpected physics issues related to the initial phase of discharge. A triple Langmuir probe (TLP) has been developed to measure time series of the floating potential, plasma electron temperature and number density over the entire discharge, allowing monitoring of the two phases of the discharge: the ECH pre-ionization phase following by the plasma current formation phase. A TLP has the ability to give time-resolved measurements of the floating potential (V_float), electron temperature (T_e) and ion saturation current (I_sat∝ n_e√kT_e). The evolution of the ECH-assisted pre-ionization and subsequent plasma current phases in one shot are well envisioned by the probe. Intense fluctuations in the plasma current phase advocate for efficient equilibrium and feedback control systems. Moreover, the emergence of some strong impurity lines in the emission spectrum, even after only a few shots, suggests a crucial need for improvements in the base vacuum level. A noticeable change in the shape of the temporal profiles of the floating potential, electron temperature, ion saturation current (I_sat) and light emission has been observed with changing hydrogen fill pressure and vertical magnetic field.     

Application of machine learning algorithms for the evaluation of seismic soil liquefaction potential

This study investigates the performance of four machine learning (ML) algorithms to evaluate the earthquake-induced liquefaction potential of soil based on the cone penetration test field case history records using the Bayesian belief network (BBN) learning software Netica. The BBN structures that were developed by ML algorithms-K2, hill climbing (HC), tree augmented naive (TAN) Bayes, and Tabu search were adopted to perform parameter learning in Netica, thereby fixing the BBN models. The performance measure indexes, namely, overall accuracy (OA), precision, recall, F-measure, and area under the receiver operating characteristic curve, were used to evaluate the training and testing BBN models’ performance and highlight the capability of the K2 and TAN Bayes models over the Tabu search and HC models. The sensitivity analysis results showed that the cone tip resistance and vertical effective stress are the most sensitive factors, whereas the mean grain size is the least sensitive factor in the prediction of seismic soil liquefaction potential. The results of this study can provide theoretical support for researchers in selecting appropriate ML algorithms and improving the predictive performance of seismic soil liquefaction potential models.     

Microwave-assisted pre-ionization experiments on GLAST-Ⅲ

GLAss Spherical Tokamak(GLAST-Ⅲ) is a spherical tokamak with an insulating vacuum vessel that has a unique single-passage capability for incident microwaves.In this work,electron cyclotron resonance heating(ECRH)-assisted plasma pre-ionization in GLAST-Ⅲ is explored for three radio-frequency(RF) polarizations(the O-,X-,and M-modes) at different toroidal-field(TF) strengths and filled gas pressures.The optimum hydrogen pressure is identified for efficient plasma pre-ionization.A comparison of the plasma pre-ionizations initiated by the O-,X-,and M-modes shows prominent differences in the breakdown time,location,and wave absorption.In the case of O-mode polarization,microwave absorption occurs for a relatively shorter duration,resulting in a bell-shaped electron-temperature(T_e) temporal profile.Microwave absorption is dominant in the case of the X-mode,leading to a broader T_e temporal profile.The M-mode discharge contains features of both the X-and O-modes.Efficient plasma pre-ionization is achieved in the X-mode polarization for the intermediate TF strengths(with a central toroidal magnetic field B_0=0.075 T).Traces of the electron-number density show a similar tendency,as revealed by T_e.These results suggest that the X-mode is the best candidate for efficient plasma pre-ionization at low filled gas pressures(~10~(-2) Pa) in small tokamaks.     

V2O3-Polymer Composite Thermistors

V₂O₃ was incorporated into polymer matrices to produce composite materials with low room-temperature resistivities and sizable positive temperature coefficient (PTC) resistance effects. In addition, a negative temperature coefficient effect, associated with the semiconductor-to-metal phase transition in V₂O₃, was also observed. The resistivity vs temperature curve for these composites resembles a square well with three temperature regimes in which the composite behaves like a semiconductor, a metal, and an insulator. The intensity of the PTC effect for these composites was found to be as large as 10 orders of magnitude.     

Migration of existing software systems to mobile computing platforms: a systematic mapping study

Mobile computing has fast emerged as a pervasive technology to replace the old computing paradigms with portable computation and context-aware communication. Existing software systems can be migrated (while preserving their data and logic) to mobile computing platforms that support portability, context-sensitivity, and enhanced usability. In recent years, some research and development efforts have focused on a systematic migration of existing software systems to mobile computing platforms.To investigate the research state-of-the-art on the migration of existing software systems to mobile computing platforms. We aim to analyze the progression and impacts of existing research, highlight challenges and solutions that reflect dimensions of emerging and futuristic research.We followed evidence-based software engineering (EBSE) method to conduct a systematic mapping study (SMS) of the existing research that has progressed over more than a decade (25 studies published from 1996–2017).We have derived a taxonomical classification and a holistic mapping of the existing research to investigate its progress, impacts, and potential areas of futuristic research and development.The SMS has identified three types of migration namely Static, Dynamic, and State-based Migration of existing software systems to mobile computing platforms.Migration to mobile computing platforms enables existing software systems to achieve portability, context-sensitivity, and high connectivity. However, mobile systems may face some challenges such as resource poverty, data security, and privacy. The emerging and futuristic research aims to support patterns and tool support to automate the migration process. The results of this SMS can benefit researchers and practitioners–by highlighting challenges, solutions, and tools, etc., –to conceptualize the state-ofthe- art and futuristic trends that support migration of existing software to mobile computing.     

Landslide damage to the board river water supply pipeline,Bromley Hill,Jamaica: Case study of a landslide caused by hurricane Gilbert (1988)

This case study highlights the importance of geotechnical investigations in the site selection, design and maintenance of life-line structures in multiple hazard prone areas. The Boar River Pipeline, carrying part of Kingston’s water supply, was damaged by a debris flow originating on the eastern slope of Bromley Hill, following the passage of hurricane Gilbert over Jamaica on September 12, 1988. Regional and site-specific geotechical investigations indicate that landslides are ubiquitous in the region, especially on east-facing slopes, and that the slide which damaged the pipelnine is a relatively shallow failure. The slide may stabilize itself in the due course of time provided there are no extreme weather events. Artificial measures of slope stabilization are recommended as a short-term solution. However, since the entire slope is involved in sliding and favourable conditions for future failures exist in the area, the better approach would be to avoid the failed slope altogether and relocate the pipeline.     

Separation of rare earth elements from sulfate leach liquor by heterocyclic nitrogen compound

Separation of rare earth dements by solvent extraction has actually been widely used in various fields from analytical chemistry to hydrometallurgy. A representative ore sample obtained from Kadabora Batholiths-Eastern Desert of Egypt, containing the multiple oxides rare earth minerals： Samarskite, Fergusonite, Betafite, and Pyrochlore, was subjected to sulfuric acid leaching. Different sets of equilibrium loading experiments were carded out on a bench scale for the extraction of rare earths （cerium and yttrium） from the sulfate leach liquor using 8,9-dihydro[1,2,4]triazolo[1,5-a]quinazolin-6（TH）-one {TQ} dissolved in methylene chloride. Stripping was carded out by 20% sodium hydroxide. A rare earth cake was produced by oxalic acid precipitation. Its purity reached 87.3%.     

Growth and characterization of V2O5 thin film on conductive electrode

Vanadium pentoxide V₂O₅ thin films were grown at room temperature on ITO coated glass substrates by electrochemical deposition. The resulting films were annealed at 300, 400 and 500°C for 1 h in ambient environment. The effect of heat treatment on the films properties such as surface morphology, crystal structure, optical absorption and photoluminescence were investigated. The x‐ray diffraction study showed that the films are well crystallized with temperatures. Strong reflection from plane (400) indicated the film's preferred growth orientation. The V₂O₅ films are found to be highly transparent across the visible spectrum and the measured photoluminescence quenching suggested the film's potential application in OPV device fabrication.