Identification of Quaternary Shape Memory Alloys with Near‐Zero Thermal Hysteresis and Unprecedented Functional Stability

Improving the functional stability of shape memory alloys (SMAs), which undergo a reversible martensitic transformation, is critical for their applications and remains a central research theme driving advances in shape memory technology. By using a thin‐film composition‐spread technique and high‐throughput characterization methods, the lattice parameters of quaternary Ti–Ni–Cu–Pd SMAs and the thermal hysteresis are tailored. Novel alloys with near‐zero thermal hysteresis, as predicted by the geometric non‐linear theory of martensite, are identified. The thin‐film results are successfully transferred to bulk materials and near‐zero thermal hysteresis is observed for the phase transformation in bulk alloys using the temperature‐dependent alternating current potential drop method. A universal behavior of hysteresis versus the middle eigenvalue of the transformation stretch matrix is observed for different alloy systems. Furthermore, significantly improved functional stability, investigated by thermal cycling using differential scanning calorimetry, is found for the quaternary bulk alloy Ti_50.2Ni_34.4Cu_12.3Pd_3.1.     

Effect of process parameters on circulating fluidized bed coal gasification using 3D full-loop CFD simulation

This article presents a 3D full-loop computational fluid dynamics (CFD) simulation of a circulating fluidized bed gasifier (CFBG). The simulation results are validated against the experimental data and found to be in good agreement. Thereupon, the effect of the process parameters, ie, temperature, pressure, air/coal (A/C) ratio, and steam/coal (S/C) ratio, on the performance of the gasifier is analyzed. The effect of temperature on the hydrodynamics was found to be small. The CO and H₂ increase, whereas the CO₂ and H₂O decrease with an increase in temperature. While the effect of pressure on the outlet species mole fraction is negligible, the gas and solid axial velocity decrease with an increase in pressure. With an increasing A/C ratio or decreasing S/C ratio, the combustion products (CO₂ and H₂O) increase, whereas the gasification products (CO and H₂) decrease due to the increase in the O₂ concentration. In addition, temperature increases with an increase in the A/C ratio or a decrease in the S/C ratio. The feed velocity increases with an increasing A/C or S/C ratio, and, accordingly, the pressure increases and bed height decreases. The CH₄ decreases in all of the cases as it is being consumed in gasification as well as combustion reactions.     

Microstructural Characteristics and Mechanical Properties of CNT/Ni Coated CNT–Dispersed Al Alloys Produced by High Energy Ball Milling and Hot Extrusion

Metals and Materials International - The effect of dispersion of carbon nanotubes (CNT) and Ni coated CNT in Al alloy (AA) on the evolution of microstructure and resultant mechanical properties are...     

Linearity improvement of gain enhanced op-amp using cross-coupled architecture

Microsystem Technologies - A novel design structure for high gain linearized operational amplifier using cross coupled differential pair is presented in the current article. This proposed circuit...     

Comprehensive survey on haze removal techniques

Image haze removal techniques are extensively used in several outdoor applications. Lack of sufficient knowledge that is required to restore hazy images, the existing techniques usually use various attributes and assign constant values to these attributes. Unsuitable assignment to these attributes does not provide desired dehazing results. The primary objective of this review paper is to provide a structured outline of some well-known haze removal techniques. This paper also focuses on the methods which can assign optimal values to image dehazing attributes. The review has revealed that the meta-heuristic techniques can attain the optimistic haze removal parameters and also concurrently develops an optimistic objective function to estimate the depth map efficiently. Finally, this paper describes the various issues and challenges of image dehazing techniques, which are required to be further studied.

     

Intradermal and follicular delivery of adapalene liposomes

Abstract

Background: Adapalene is a widely used topical anti-acne drug; however, it has many side effects. Liposomal drug delivery can play a major role by targeting delivery to pilosebaceous units, reducing side effects and offering better patient compliance.

Objective: To prepare and evaluate adapalene-encapsulated liposomes for their physiochemical and skin permeation properties.

Methods: A liposomal formulation of adapalene was prepared by the film hydration method and characterized for shape, size, polydispersity index (PDI), encapsulation efficiency and thermal behavior by techniques such as Zetasizer®, differential scanning calorimetry and transmission electron microscopy. Stability of the liposomes was evaluated for three months at different storage conditions. In vitro skin permeation studies and confocal laser microscopy were performed to evaluate adapalene permeation in pig ear skin and hair follicles.

Results: The optimized process and formulation parameters resulted in homogeneous population of liposomes with a diameter of 86.66?±?3.5?nm in diameter and encapsulation efficiency of 97.01?±?1.84% w/w. In vitro permeation studies indicated liposomal formulation delivered more drug (6.72?±?0.83?μg/cm²) in hair follicles than gel (3.33?±?0.26?μg/cm²) and drug solution (1.62?±?0.054?μg/cm²). Drug concentration delivered to the skin layers was also enhanced compared to other two formulations. Confocal microscopy images confirmed drug penetration in the hair follicles when delivered using the liposomal formulation.

Conclusion: Adapalene was efficiently encapsulated in liposomes and led to enhanced delivery in hair follicles, the desired target site for acne.     

Bubble Dynamics and Heat Transfer during Pool and Flow Boiling

A large number of studies of bubble growth rate and departure diameter have been reported in the literature. Because of uncertainty in defining the shape of an evolving interface, empirical constants are invariably used to match the model predictions with data. This is especially true when force balance is made on a vapor bubble to determine the departure diameter. In this paper, the results of an alternate approach based on a complete numerical simulation of the process are given. Single and multiple bubbles are considered for both pool and flow boiling. The simulations are based on the solution of the conservation equations of mass, momentum, and energy for both phases. Interface shape is captured through a level set function. A comparison of bubble shape during evolution, bubble diameter at departure, and bubble growth period is made with data from well-controlled experiments. Among other variables, the effect of magnitude of gravity and contact angle is explicitly investigated.