Magnetocaloric Effect in (001)-Oriented MnAs Thin Film

In this paper, a phenomenological model is used to calculate magnetocaloric properties of (001)-oriented MnAs films. Based on this model, it has been predicted the values of the magnetocaloric properties from calculation of magnetization as a function of temperature under very low external magnetic field change of 0.03 T. Moreover, a control of the change of a broad range of temperature could be achieved by tuning several substrate temperatures. This advantage should result in more efficient and global cooling devices. It is suggested that (001)-oriented MnAs films are suitable candidates as refrigerants near a room-temperature region with a large temperature span.     

Springback prediction and reduction in deep drawing under influence of unloading modulus degradation

Springback is considered as one of the major problems in deep drawing of high-strength steels (HSS) and advanced high-strength steels (AHSS) which occurs during the unloading of part from the tools. With an ever increasing demand on the automotive manufactures for the production of lightweight automobile structures and increased crash performance, the use of HSS and AHSS is becoming extensive. For the accurate prediction of springback, unloading behavior of dual phase steels DP600, DP1000 and cold rolled steel DC04 for the deep drawing process is investigated and a strategy for the reduction of springback based on variable blankholder force is also presented. Cyclic tension compression tests and LS-Opt software are used for the identification of material parameters for Yoshida-Uemori (YU) model. Degradation of the Young’s modulus is found to be 28 and 26 and 14 % from the initial Young’s modulus for DP600, DP1000 and for the DC04 respectively for the saturated value. A finite element model is generated in LS-DYNA based on the kinematic hardening material model, namely Yoshida-Uemori (YU) model. The validation of numerical simulations is also carried out by the real deep drawing experiments. The springback could be predicted with the maximum deviation of 1.1 mm for these materials. For DP1000, the maximum springback is reduced by 24.5 %, for DP600 33.3 and 48.7 % for DC04 by the application of monotonic blankholder force instead of a constant blankholder force of 80 kN. It is concluded that despite the reduction of Young’s modulus, the springback can be reduced for these materials by increasing the blankholder force only in last 13 % of the punch travel.     

Optimal Scanning Protocols for Dual-Energy CT Angiography in Peripheral Arterial Stents: An in Vitro Phantom Study

Objective: To identify the optimal dual-energy computed tomography (DECT) scanning protocol for peripheral arterial stents while achieving a low radiation dose, while still maintaining diagnostic image quality, as determined by an in vitro phantom study. Methods: Dual-energy scans in monochromatic spectral imaging mode were performed on a peripheral arterial phantom with use of three gemstone spectral imaging (GSI) protocols, three pitch values, and four kiloelectron volts (keV) ranges. A total of 15 stents of different sizes, materials, and designs were deployed in the phantom. Image noise, the signal-to-noise ratio (SNR), different levels of adaptive statistical iterative reconstruction (ASIR), and the four levels of monochromatic energy for DECT imaging of peripheral arterial stents were measured and compared to determine the optimal protocols. Results: A total of 36 scans with 180 datasets were reconstructed from a combination of different protocols. There was a significant reduction of image noise with a higher SNR from monochromatic energy images between 65 and 70 keV in all investigated preset GSI protocols (p < 0.05). In addition, significant effects were found from the main effect analysis for these factors: GSI, pitch, and keV (p = 0.001). In contrast, there was significant interaction on the unstented area between GSI and ASIR (p = 0.015) and a very high significant difference between keV and ASIR (p < 0.001). A radiation dose reduction of 50% was achieved. Conclusions: The optimal scanning protocol and energy level in the phantom study were GSI-48, pitch value 0.984, and 65 keV, which resulted in lower image noise and a lower radiation dose, but with acceptable diagnostic images.     

Synthesis of reductive responsive polyphosphazenes and their fabrication of nanocarriers for drug delivery application

Reductive responsive nanovehicles have the ability to deliver the anticancer drugs to intracellular compartments. The purpose of this study was to develop reductive sensitive nanocarriers based on polyphosphazenes. Amphiphilic polyphosphazenes with hydrophilic reductive sensitive side group and different molecular weights were synthesized and characterized. The synthesized copolymers show solvent dependent self-aggregation and form spherical micelles by using THF as co-organic solvent in dialysis method with critical micelle concentration value ranging from 5.73 µg/mL to 11.24 µg/mL. Micelles can encapsulate the hydrophobic drugs such as camptothecin (CPT) and indomethacin. In in vitro release experiments, CPT-loaded micelles release 70–80% of the loaded CPT in the presence of reducing agent dithiothreitol within 15 h. The results indicate that these reductive sensitive amphiphilic polyphosphazenes may find an application as anticancer drug carriers for safe drug delivery.     

Biochemical, hematologic, and immunologic alterations following hepatic cryotherapy

BACKGROUND: Cystoid macular edema is a common clinical finding following intraocular surgery. Certain medications have been associated with an increased incidence of cystoid macular edema. This article describes the clinical findings in two eyes of two patients in whom cystoid macular edema developed directly following treatment with the anti-glaucoma medication latanoprost, and assesses the possible causal relationship. CASE REPORTS: Clinical correlative and angiographic studies of two patients in a referral practice are presented. The main outcome measurement was visual acuity and fundus examination on discontinuation of latanoprost. RESULTS: Cystoid macular edema developed in two pseudophakic patients after the use of latanoprost. CONCLUSION: Latanoprost should be used with caution in pseudophakic and aphakic patients--especially those with retinal vascular fragility, any inflammatory uveal disease, or other factors that may predispose to the breakdown of the blood-retinal barrier.     

Crystallization mechanisms of calcium phosphate cement for biological uses

Self-setting calcium phosphate cement for dental or surgical applications can be prepared by the addition of a liquid to a mixture of acidic and basic calcium phosphate. After hardening, the final compound becomes hydroxyapatite. Using an orthogonal central composite plan, the main factors which control the setting and the final hardness of the cement were defined and models are proposed. The mechanisms of crystallization, the role of free and linked water, and the nature of the final and intermediate compounds are described.This paper was accepted for publication after the 1995 Conference of the European Society of Biomaterials, Oporto, Portugal, 10–13 September.     

Cost-effective wastewater treatment and recycling in mini-plants using mass integration

This work illustrates the use of a mass integration approach to cost-effectively reduce wastewater treatment and discharge in mini-industrial plants. The approach focuses on the use of functional analysis, graphical analysis tools, and mathematical formulation to simplify the size of the problem and identify separation/interception scenarios. Sensitivity analysis is then used to compare all potential interception/separation scenarios identified by the analysis tools. The proposed approach is utilized to systematically optimize the cost of wastewater treatment in a fabric plant in Dubai, UAE. The solution involves the use of a settling tank (already exists in the process), reverse osmosis, and an evaporator to minimize the cost of wastewater treatment in the plant for the reduction of biochemical oxygen demand, chemical oxygen demand, total dissolved solids, and total suspended solids. Electronic Publication     

Influence of hydrophobe content on phase coexistence curves of aqueous two‐phase solutions of associative polyacrylamide copolymers and poly(ethylene glycol)

The influence of hydrophobe content and type on the phase coexistence curves of aqueous two‐phase polymer systems containing poly(ethylene glycol) and associative polyacrylamide copolymers has been investigated. The top phase was poly(ethylene glycol)‐rich while the bottom phase was rich in the copolymer. Increased intramolecular association resulting from increased hydrophobe content was found to increase compatibility of the two polymers in the bottom phase. Large size asymmetry was found to be an important factor in determining the binodal curve. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1351–1355, 2003