Mixing and segregation in a liquid fluidized bed of particles with different size and density

Experimental studies have been carried out on fluidization of irregular particle mixtures of different size and density. The mixing and segregation phenomena could be interpreted on the basis of the diffusion model of Kennedy and Bretton. The dependence of computed particle dispersion coefficient on liquid velocity, particle density and size has been discussed.     

A Halogen-Bonded Organic Framework (XOF) Emissive Cocrystal for Acid Vapor and Explosive Sensing,and Iodine Capture

There is a strong and urgent need for efficient materials that can capture radioactive iodine atoms from nuclear waste. This work presents a novel strategy to develop porous materials for iodine capture by employing halogen bonding, mechanochemistry and crystal engineering. 3D halogen-bonded organic frameworks (XOFs) with guest-accessible permanent pores are exciting targets in crystal engineering for developing functional materials, and this work reports the first example of such a structure. The new-found XOF, namely TIEPE-DABCO , exhibits enhanced emission in the solid state and turn-off emission sensing of acid vapors and explosives like picric acid in nanomolar quantity. TIEPE-DABCO captures iodine from the gas phase (3.23 g g⁻¹ at 75 °C and 1.40 g g⁻¹ at rt), organic solvents (2.1 g g⁻¹), and aqueous solutions (1.8 g g⁻¹ in the pH range of 3–8); the latter with fast kinetics. The captured iodine can be retained for more than 7 days without any leaching, but readily released using methanol, when required. TIEPE-DABCO can be recycled for iodine capture several times without any loss of storage capacity. The results presented in this work demonstrate the potential of mechanochemical cocrystal engineering with halogen bonding as an approach to develop porous materials for iodine capture and sensing.     

Nanoscopic Characterisation of Individual Endogenous Protein Aggregates in Human Neuronal Cells

The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson's and Alzheimer's diseases. These aggregates are highly heterogeneous in structure, generally of low abundance and typically smaller than the diffraction limit of light (≈250 nm). To overcome the challenges these characteristics pose to the study of endogenous aggregates formed in cells, we have developed a method to characterise them at the nanometre scale without the need for a conjugated fluorophore. Using a combination of DNA PAINT and an amyloid‐specific aptamer, we demonstrate that this technique is able to detect and super‐resolve a range of aggregated species, including those formed by α‐synuclein and amyloid‐β. Additionally, this method enables endogenous protein aggregates within cells to be characterised. We found that neuronal cells derived from patients with Parkinson's disease contain a larger number of protein aggregates than those from healthy controls.     

Regime Transition and Holdup in Pulsed Sieve-Plate and Pulsed Disc-and-Doughnut Columns: A Comparative Study

This study reports a detailed comparison of dispersed-phase holdup and onset of different operating regimes in PSPC (pulsed sieve-plate column) and PDDC (pulsed disc-and-doughnut column) for 3 N nitric acid–30% tributyl phosphate (TBP) in dodecane system. Experiments are performed in a 3-inch glass column with SS internals for aqueous-continuous mode of operation keeping O/A ratio at 1:3. The effects of column throughput (0.0097–0.0219 m/s) and pulsing velocity (0.011–0.039 m/s) on holdup and onset of operating regimes are studied and compared. Holdup in PDDC is found to be consistently more than that in PSPC. Onset of dispersion regime is found to be delayed in PDDC in comparison to PSPC. Insights into the movement of a typical dispersed-phase drop under pulsatile flow in PSPC have been provided. Additionally, a sensitivity analysis of the effect of pulsing velocity on holdup in PDDC and PSPC is reported. For the phase system and O/A ratio used in the experiments, holdup in PSPC is observed to be more sensitive to variation in pulsing velocity as compared to PDDC. Efficacy of several previously reported correlations to predict dispersed-phase holdup in PSPC and PDDC is evaluated using the experimental data generated in this study.     

Design and Analysis of 150° Bend SIW and Corrugated SIW Bandpass Filter with Multiple Transmission Zeroes Using Reactive Periodic Structures Suitable for Microwave Integrated Circuits (MICs)

Keller SYMplus CNC which is developed by Germany’s Keller company is a software which used for NC programming and simulation. This paper described and analyzed the characteristics of Keller SYMplus CNC software in NC programming and simulation from four aspects, model design, rapid manufacturing, machining simulation and post processing. Then compares Keller SYMplus CNC with commonly used NC programming and simulation software UG, MasterCAM, and CAXA from the profile milling and teaching function.     

Facile preparation of light-weight biodegradable and electrically conductive polymer based nanocomposites for superior electromagnetic interference shielding effectiveness

Harmful electromagnetic radiations that are generated from different electronic devices could be absorbed by a light weight and mechanically flexible good electromagnetic interference (EMI) shielding polymer nanocomposite. On the other hand, different electronic wastes (“e-wastes”) which are generally polymer building materials generated from wastes of dysfunctional electronic devices are not naturally biodegradable. Our recent effort has been employed to produce bio-degradable EMI shielding polymer nanocomposite. For that purpose, we had prepared a 50:50 ratio polylactic acid/thermoplastic polyurethane polymer nanocomposite by mixing the conducting carbon black with the blend following the facile and industrially feasible solution mixing method. Morphological characterizations by scanning electron microscopy and transmission electron microscopy analysis revealed the co-continuous morphology of the neat blend as well as polymer nanocomposites with the preferential distribution of conductive filler on a particular polymer phase. The polymer nanocomposites gave good mechanically with improved thermal properties. We got EMI shielding effectiveness around −27 dB with a low percolation threshold at around 30 wt% filler loading in the polymer nanocomposite at the X-band frequency domain (8.2–12.4 GHz). Later we had studied the biodegradability of the PLA/TPU along with their composites (T_XP_XC_X) by employing the respirometry method and got a satisfactory result to ensure their biodegradability.     

A lab-scale spinning basket membrane module for the assessment of humic acids ultrafiltration with effect of sonication on membrane fouling

In the current study, humic acids ultrafiltration was explored using spinning basket membrane module at different transmembrane pressure drops (207, 276, 345, and 414?kPa), rotational speeds (10.47, 20.99, 31.41, 52.36, and 73.30?rad?s^?1) and different concentration of HAs (50, 150, and 250?mg?L^?1). The internal pore blocking characteristics was investigated using modified Hermia’s pore clogging models like complete, standard, intermediate pore blocking, and the cake filtration model. After ultrafiltration of 50?mg?L^?1 solution, the cleaning process of fouled membrane was carried out using a system inbuilt back rotation of the membrane basket (10.47–52.36?rad?s^?1) and compared with the effect of ultrasonication (ultrasound power: 120?W, frequency: 50?kHz) for the same fouled membrane at the different sonication time interval (5–25?min). The maximum cleaning efficiency of 88% was observed at 25?min of ultrasonication of fouled membrane.     

A FREQUENCY DOMAIN APPROACH FOR THE ESTIMATION OF PARAMETERS OF SPATIO‐TEMPORAL STATIONARY RANDOM PROCESSES

A frequency domain methodology is proposed for estimating parameters of covariance functions of stationary spatio‐temporal processes. Finite Fourier transforms of the processes are defined at each location. Based on the joint distribution of these complex valued random variables, an approximate likelihood function is constructed. The sampling properties of the estimators are investigated. It is observed that the expectation of these transforms can be considered to be a frequency domain analogue of the classical variogram. We call this measure frequency variogram. The method is applied to simulated data and also to Pacific wind speed data considered earlier by Cressie and Huang (1999). The proposed method does not depend on the distributional assumptions about the process.     

Scandium ion doped yttrium oxide transparent ceramic from nitrate alanine microwave combustion synthesized nanopowders

One atomic percent Neodymium ion doped Yttrium oxide, with 25 at% scandium ion (Nd_0.02Sc_0.5Y_1.48O₃), was synthesized by nitrate alanine microwave gel combustion followed by calcinations at 1000 °C for 2 h. Phase purity of nanopowder was characterized by X-Ray Diffraction (XRD). Neodymium and scandium ion doping was confirmed by cell parameter calculation and Scanning Electron Microscope-Electron Dispersive X-ray (SEM-EDX) analysis. Particles with size range 25–35 nm with close to spherical shape were obtained as observed by Transmission Electron Microscopy (TEM). Powder on compaction followed by vacuum sintering at 1765 °C for 40 min led to the formation of ceramic with 76% transmission at 2500 nm compared to translucent ceramic obtained without scandium ion doping. This indicates formation of highly sinterable neodymium doped yttrium oxide nanopowders by nitrate alanine microwave gel combustion route with scandium ion additive. Further the absorption and emission bands of Nd_0.02Sc_0.5Y_1.48O₃ are inhomogeneously broadened and fluorescence lifetime is longer than Nd_0.02Y_1.98O₃.