Zero resistance states in modified Y-Ba-Cu-O system with transition temperatures above 135 K

Superconducting transition of minor-dispersed phase in modified YBa₂Cu₃O_7?δ samples is found to occur at around 140K. The amount of this minor phase is enough to provide zero resistivity above 135 K. The measurements of the electrical resistivity indicated that the material is stable, thermally recyclable and reproducible. X-ray analysis of the sample with the highestT _c shows a major phase with perovskite-like structure witha=3·820(1) Å;b=3·873(1) Å andc=11·659(2) Å along with several unidentified weak peaks. Magnetic measurements confirmed the mixed-phase nature with diamagnetic transition temperatures at 137,91 and 86 K. The minor phase responsible for superconductivity with zero resistivity above 135 K is about 0·4% of the bulk and its nature is still unidentified. The details of the preparation and chemical modification process and the results are presented.     

Nephrotoxicity of cadmium-metallothionein: protection by zinc and role of glutathione

BACKGROUND: In vitro studies have shown an antiproliferative effect of tumor necrosis factor (TNF) against various nonsmall cell lung carcinoma (NSCLC) cell lines. However, clinical trials of combined interleukin-2 and TNF-alpha in patients with advanced NSCLC have demonstrated both conflicting and disappointing results. METHODS: Immunohistochemical (IHC) staining was performed on formalin fixed, paraffin embedded tissues from 39 bronchogenic adenocarcinomas and 32 squamous cell carcinomas using polyclonal antibodies against TNF-alpha, TNF-beta, TNF-R1, and TNF-R2 proteins. IHC positivity was correlated with tumor stage, grade, and patient survival. RESULTS: Significant coexpression of TNF-alpha, TNF-beta, TNF-R1, and TNF-R2 was observed in NSCLC (significance range, P < 0.001-0.02). Although immunoreactivity for TNFs remained high in all tumor stages, a loss of TNF-R expression was found in advanced NSCLC (P < 0.006 for TNF-R1 and P < 0.003 for TNF-R2), suggesting down-regulation of TNF-Rs in the process of tumor progression. When all stages were considered together, immunoreactivity for TNF-beta(P < 0.001), TNF-R1, and TNF-R2 (both P < 0.001) significantly correlated with favorable outcome in univariate analysis. However, when stages were studied separately, an association between immunopositivity for TNF-Rs and favorable prognosis was found only in NSCLC without distant metastasis (P < 0.04 and P < 0.005 for TNF-R1 and TNF-R2 in Stage I [according to the American Joint Committee on Cancer staging system] disease, and P < 0.03 and P < 0.02 for TNF-R1 and TNF-R2 in Stage III disease). On multivariate analysis, increased expression of TNF-R1 (P < 0.003) and TNF-R2 (P < 0.001) as well as tumor stage (P < 0.001) independently predicted favorable outcome in patients with NSCLC. CONCLUSIONS: Although NSCLC exhibits strong coexpression of TNF-alpha, TNF-beta, TNF-R1, and TNF-R2, there is a loss/down-regulation of TNF receptors in high stage tumors. TNF-R1 and TNF-R2 positivity independently predicts favorable outcome in NSCLC, particularly in tumors with no clinically distant metastasis. The current study supports a role for TNFs and their receptors in the evolution and progression of NSCLC.     

Electrochemical behaviour of lead chloride (PbCl2) in dimethylsulphoxide (DMSO)—II. a chronopotentiometric study

In our earlier electrode kinetic studies (chronopotentiometric) of lead chloride (PbCl₂) in dimethylsulfoxide (DMSO), the points in the plot of E, vs log (τ^1/2 ? t^1/2) were linear in the form of a wave. This situation was similar to that observed by Delahay in the chronopotentionmetric reduction of chromate ion (aqueous medium) and thought to be due to a prekinetic step. To verify the presence of a prekinetic step in our case a survey of iτ^1/2vs i for a wider range of lead chloride concentration was started. But a distortion observed in the initial part of the curve (from 4·0 mM PbCl₂) was another point of similarity with that of chromate ion. This led us to consider the polarographic and chronopotentiometric reduction behaviour of CrO^2?₄ in two different electrolytes sodium hydroxide and sodium carbonate. Such considerations justify the presence of a prekinetic step in electrochemical reduction of chromate. Such a prekinetic step, probably the dissociation of PbCl₂, is verified and Kk^1/2₂ values for this coupled chemical reaction are determined according to the transition time expressions of Delahay and Dracka.     

A neuroplasticity-inspired neural circuit for acoustic navigation with obstacle avoidance that learns smooth motion paths

Neural Computing and Applications - Acoustic spatial navigation for mobile robots is relevant in the absence of reliable visual information about the target that must be localised. Reactive robot...     

Evaluation of Failure Capacity of Offshore Riser Protectors Under Vessel Impact

Conventional riser protectors, also known as riser-guards, are installed on fixed offshore platforms to protect risers from vessel impact. These space frame structures made of hollow mild steel tubular sections are mainly designed using the approach of boat fenders which may result in over- or under-protection provided to risers. Lack of in-depth study on the dynamic behavior and capacity of conventional riser-guards is considered to be the primary challenge for creative and efficient design of conventional riser protectors. This paper presents a detailed numerical investigation on the dynamic response, damage and failure mechanics of conventional steel riser-guards during accidental vessel collision using nonlinear finite element analysis. Collision forces equivalent to vessel collision with riser-guards for different spans were estimated to provide information for load-based design. Variation in damage patterns for broadside and bow impacts is presented for riser protectors with different spans. The actual capacity of a typical riser-guard in terms of maximum impact energy sustainable prior to failure was also determined from dynamic pushover analysis. The structural response and damage parameters presented in this study can be used for better understanding of damage mechanism and failure capacity of riser protectors which can act as a baseline for further design optimization, as well as the development of other alternative riser protection systems.     

Compact and High Speed Architectures of KASUMI Block Cipher

Wireless Personal Communications - This paper proposes highly compact and high speed hardware architectures of 64-bit KASUMI block cipher for wide range of wireless applications. A novel...     

HMX based enhanced energy LOVA gun propellant

Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 degrees C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 microm HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.     

A study of cloud classification with neural networks using spectraland textural features

The problem of cloud data classification from satellite imagery using neural networks is considered. Several image transformations such as singular value decomposition (SVD) and wavelet packet (WP) were used to extract the salient spectral and textural features attributed to satellite cloud data in both visible and infrared (IR) channels. In addition, the well-known gray-level cooccurrence matrix (GLCM) method and spectral features were examined for the sake of comparison. Two different neural-network paradigms namely probability neural network (PNN) and unsupervised Kohonen self-organized feature map (SOM) were examined and their performance were also benchmarked on the geostationary operational environmental satellite (GOES) 8 data. Additionally, a postprocessing scheme was developed which utilizes the contextual information in the satellite images to improve the final classification accuracy. Overall, the performance of the PNN when used in conjunction with these feature extraction and postprocessing schemes showed the potential of this neural-network-based cloud classification system.     

Thermotropic liquid crystalline behavior of cholesterol‐linked hydroxyethyl cellulose

A series of monocholesterylsuccinate (ChMS) derivatives of hydroxyethyl cellulose (HEC) were prepared with degree of substitution ranging from 0.6 to 2.0. They were characterized by ChMS content, infrared spectroscopy, polarizing microscopy, and differential scanning calorimetry. All these polymers displayed thermotropic liquid crystalline behavior on heating as well as on cooling. The transformation temperature was found to be influenced by the degree of substitution. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 763–770, 1999     

A Robust Wearable Point-of-Care CNT-Based Strain Sensor for Wirelessly Monitoring Throat-Related Illnesses

Point-of-care testing (POC) has the ability to detect chronic and infectious diseases early or at the time of occurrence and provide a state-of-the-art personalized healthcare system. Recently, wearable and flexible sensors have been employed to analyze sweat, glucose, blood, and human skin conditions. However, a flexible sensing system that allows for the real-time monitoring of throat-related illnesses, such as salivary parotid gland swelling caused by flu and mumps, is necessary. Here, for the first time, a wearable, highly flexible, and stretchable piezoresistive sensing patch based on carbon nanotubes (CNTs) is reported, which can record muscle expansion or relaxation in real-time, and thus act as a next-generation POC sensor. The patch offers an excellent gauge factor for in-plane stretching and spatial expansion with low hysteresis. The actual extent of muscle expansion is calculated and the gauge factor for applications entailing volumetric deformations is redefined. Additionally, a bluetooth-low-energy system that tracks muscle activity in real-time and transmits the output signals wirelessly to a smartphone app is utilized. Numerical calculations verify that the low stress and strain lead to excellent mechanical reliability and repeatability. Finally, a dummy muscle is inflated using a pneumatic-based actuator to demonstrate the application of the affixed wearable next-generation POC sensor.