Fast growth of ultrananocrystalline diamond films by bias-enhanced nucleation and growth process in CH4/Ar plasma

[[abstract]]This letter describes the fast growth of ultrananocrystalline diamond (UNCD) films by bias-enhanced nucleation and growth process in CH4/Ar plasma. The UNCD grains were formed at the beginning of the film's growth without the necessity of forming the amorphous carbon interlayer, reaching a thickness of ∼380 nm in 10 min. Transmission electron microscopic investigations revealed that the application of bias voltage induced the formation of graphitic phase both in the interior and at the interface regions of UNCD films that formed interconnected paths, facilitating the transport of electrons and resulting in enhanced electron field emission properties.[[booktype]]紙本[[countrycodes]]US

An efficient computational technique for solving the Fokker–Planck equation with space and time fractional derivatives

AbstractThis paper presents numerical solutions of the linear and nonlinear Fokker–Planck partial differential equations [FPPDEs] with space and time fractional derivatives through analytical solutions. These are treated by two analytical methods, namely, fractional reduced differential transform method [FRDTM] and fractional variational iteration method [FVIM] followed by some examples. Numerical results obtained by both FRDTM and FVIM are compared with some existing methods in the literature. This comparison shows the supremacy of FRDTM over FVIM and existing methods in terms of accuracy, simplicity and reliability

Superficial venous patterns of the cubital fossa among volunteers from Hospital Kuala Lumpur

Introduction Cubital fossa is a space in anterior to the elbow which contains important vessels and nerves in the arm. Superficial veins of cubital fossa are commonly used for blood sampling, transfusions and for intravenous injections often under conditions of emergency. These veins are useful in arteriovenous fistula creation for hemodialysis. Besides that, they are used for creation of forearm flaps in plastic surgery. The arrangement of the superficial veins in the cubital fossa however is subjected to considerable variation. Different patterns of superficial cubital veins and their percentages of occurrence have been reported in various races. This prospective study among Malaysians from three races (Malays, Chinese and Indians) was planned since the superficial veins in the cubital fossa are important clinically and their arrangements are subject to racial variation. Objectives The aim of the study is to observe and describe the distribution of anatomical variations of the superficial veins of the cubital fossa among Malay, Chinese and Indian volunteers from Hospital Kuala Lumpur. Methodology and Study Design The study is designed as a descriptive cross-sectional survey involving a simple examination of the superficial veins of cubital fossa among volunteers from Hospital Kuala Lumpur. My sample is composed of three hundred volunteers from three major ethnicities Malays, Chinese and Indians aged from eighteen and above. I, myself performed the duplex ultrasound assessment with the guidance from my supervisors in the vascular unit HKL. The patterns of the veins were drawn onto a survey form. Results Based on my analysis, the commonest type of anastomosis seen was type 1 in both genders with female having 33.3% and male having 34.0% on the right cubital fossa and 32.0% in female and 34.0% in male on the left cubital fossa. Type 1 was the commonest among Malays and Indians. It was 40.0% and 37.0% of right and left cubital fossa in Malays. Indians meanwhile had 36.0% and 41.0% on the right and left cubital fossa. While in Chinese type 3 of anastomosis observed the most. It was 38.0% and 40.0% on right and left cubital fossa. The mixed type combination on both right and left cubital fossa was the highest prevalence in all 3 major ethnicities. There was no significant difference between gender and patterns but there was a significant difference in between ethnicities and patterns of cubital fossa. Conclusion Superficial veins of cubital fossa have their clinical importance. The understanding of patterns in genders, ethnicities and combination patterns of both cubital fossas will assist in clinical procedures. Duplex ultrasound has provided a great understanding of the anatomy of superficial veins of cubital fossa

LC-MS/MS STUDY OF THE TRACE LEVEL IMPURITIES OF IRBESARTAN AN ANGIOTENSIN II RECEPTOR ANTAGONIST MOLECULE TO ITS ORIGIN THROUGH nMS2 TECHNIQUE

Objective: The mass characterization of five trace level related impurities of Irbesartan was performed through the “nMS2” technique of triple quadrupole mass spectrometer and also to Correlated to the impurity origin. Methods: A simple and effective patented process was applied to get the impurity profile, and mass characterization was performed through the “nMS2” technique of triple quadrupole mass spectrometer analyser. Results: The simple production scan in differential collision energies is coined as “nMS2” technique of the triple quadrupole analyzer. The molecular ion fragmentation occurs with multiple collision energies and provides meaningful MSMS fragments for characterizing five trace level impurities less than 0.5% of angiotensin II receptor antagonist-Irbesartan. The origin of the impurity formation in the synthetic process was successfully related to the Spiro ketones. Conclusion: The results obtained in this research clearly indicates the approach of “nMS2” technique was very useful in the identification and structural prediction of trace level related impurities of Irbesrtan

Implementation of Deduplication on Encrypted Big-data using Signcryption for cloud storage applications

As Big Data Cloud storage servers are getting widespread the shortage of disc space within the cloud becomes a major concern. The elimination of duplicate or redundant data, particularly in computer data is named deduplication. Data deduplication is a method to regulate the explosive growth of information within the cloud storage, most of the storage providers are finding more secure and efficient methods for their sensitive method. Recently, a noteworthy technique referred to as signcryption has been proposed, in which both the properties of signature (ownership) and encryption are simultaneously implemented with better performance According to deduplication, we introduce a method that can eliminate redundant encrypted data owned by different users. Furthermore, we generate a tag which will be the key component of big data management. We propose a technique called digital signature for ownership verification. Convergent encryption also called for a content hash key cryptosystem. Convergent encryption is an encryption approach that supports deduplication. With this encryption technique, the encryption key is generated out of a hash of plain text. Therefore applying this technique, identical plaintexts would turn out the same ciphertext

Multiband monopole antenna for mobile applications

— In this paper, a multiband monopole antenna has been proposed for mobile applications. The monopole antenna has simple structure with a physical size of 15 cm × 7 cm. The antenna consists of monopole shape loaded by a set of folded arms with a varying length which lead to a better impedance matching result and multiband performance. The simulated results show that the proposed antenna provide multiband frequency operation of 0.8 GHz, 1.8 GHz 2.1 GHz, 2.6 GHz and 3.5 GHz which covers the range from 0 to 4 GHz. The antenna is designed to operate at sub-6 GHz which proposed as lower frequency band to deliver 5G in early stage. The designed antenna has been fabricated and measured to validate the simulated results. RF Coaxial U.FL Connector was used as the port connector. The measurement results agrees well with the simulated ones for all frequency bands

Understanding different factors affecting Supersonic Particle Deposition (SPD) repaired Al 7075-T651 plate for structural restoration

One of the main challenges in maintaining aging aircraft is to find a reliable, effective and economic repair process, for both non-structural and structural repairs. Supersonic particle technology (SPD) aka Cold Spray (CS) has proved to be an effective geometry restoration technology and has the potential to repair/restore/enhance the airworthiness of aging aircraft. Al 7075-T651 is highly susceptible for stress crossing cracking compared to –T7351 temper. Mechanism involved in environment assisted cracking (EAC) such as corrosion fatigue primarily in conventional product forms such as rolled plate, extrudate or forging in Al 7075 is complex. Fundamental research concerning the driving force and micro-mechanism involved in EAC is still not matured, and, not completely understood in Al alloys. In addition, the effect of different factors such as high strain rate deformed layers, residual stress in the coating and substrate and presence of micro defects makes more complex in understanding the EAC in SPD repair subjects. In light of the complex nature of the SPD structure, systematic evaluation was carried out to determine various factors affecting the EAC behavior of the SPD repair. Thus, this presentation focuses on a brief overview on the application of this technology for corrosion repair followed by experimental study and fractographic analysis of SPD repaired Al 7075-T651 0.25” plate aimed at restoring the structural functionality. To study the structural behavior of the SPD coated 7075 Al, both static and fatigue performance were evaluated in ambient and humid environment. The study involves simulating a 20% thickness loss by milling Al 7075 master plates (9.1” x 8.75”) followed by depositing Al 7075 spray atomized powder using SPD process. Test coupons were extracted from this master plate; orientation and location of the individual test specimen origin were tracked. The presentation includes factors affecting the quality of the SPD coating specifically for structural application and how to exploit these factors in qualifying a SPD coating. Test results are validated and supported by detailed fractographic studies. Emphasis will be given to failure modes and mechanism involved on these SPD coated specimens tested under cyclic loads, and, under ambient and humid environments will be discussed

Prediction of Stability and Thermal conductivity of MgO Nanofluids using CCRD Statistical Design Analysis

Magnesium oxide nanopowders were synthesized by chemical reduction method in which sodium hydroxide solution was used as a reducing agent. Magnesium nitrate (MgNO3.6H2O) precursor was used for the synthesis of MgO nanopowders. Solid state characterizations of synthesized nanopowders were carried out by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. Using two step method, synthesized nanopowders were prepared as nanofluids by adding water and ethylene glycol (55:45). Thermal conductivity measurements of prepared nanofluids were studied using transient hot wire apparatus in which maximum thermal conductivity enhancement was observed in nanofluid. CCRD design has been applied to optimize the performance of nanofluid systems. In this regard, the performance was evaluated by measuring the stability and thermal conductivity ratio based on the critical independent variables such as temperature, particle volume fraction and the pH of the solution. A total of 20 experiments were accomplished for the construction of second-order polynomial equations for both target outputs. All the influential factors, their mutual effects and their quadratic terms were statistically validated by analysis of variance (ANOVA). The optimum stability and thermal conductivity of MgO nanofluids with various temperature, volume fraction and particle fraction were studied and compared with experimental reults. The results revealed that, at increase in particle concentration and pH of nanofluids at certain point would increase thermal conductivity and become stable at nominal temperature.  According to the results, the predicted values were in reasonable agreement with the experimental data as more than 95%  of the variation could be predicted by the CCRD model for thermal conductivity ratio and zeta potential