[en] A novel sensor for the determination of 5-fluorouracil was constructed by electrochemical deposition of methylene blue on surface of carbon paste electrode. The electrode surface morphology was studied using Atomic force microscopy and XRD. The electrochemical activity of modified electrode was characterized using cyclic voltammetry and differential pulse method. The developed sensor shows impressive enlargement in sensitivity of 5-fluorouracil determination. The peak currents obtained from differential pulse voltammetry was linear with concentration of 5-fluorouracil in the range 4 × 10"−"5–1 × 10"−"7 M and detection limit and quantification limit were calculated to be 2.04 nM and 6.18 nM respectively. Further, the sensor was successfully applied in pharmaceutical and biological fluid sample analysis. - Highlights: • Electrochemical oxidation of 5-fluorouracil has been investigated for first time at methylene blue modified carbon paste electrode • The electrode process was irreversible and diffusion controlled • Probable electrochemical mechanism was proposed which involved two proton and two electron transfer reaction • The LOD and LOQ values were calculated to be 2.04 nM and 6.18 nM, respectively, with good selectivity and sensitivity. • Proposed method was applied to 5-Fluorouracil determination in pharmaceutical and spiked human urine samples

[en] Plastic scintillators with Wavelength Length Shifting optical fiber readouts have become very common in high energy physics experiments. After considering which plastic scintillator and which optical fiber to use, a lot of R and D goes into how to marry the scintillator to the fiber to make an efficient detector. A great constraint is usually the space available for the module in the data acquisition system. The rule of thumb is to get optimum efficiency with the minimum of fiber, ease of handling, etc

[en] This article discusses the fabrication and bending strength of five-layer functionally graded material (FGM) coated aluminum plate. The volume fractions of ceramic (Al₂O₃) and metal (SS) constituent for each layer were evaluated by a simple power law index and the rule of mixture. A homogeneous mixture of components was done by a ball mill. The FGM coating was successfully prepared on the aluminum plate by an advanced plasma spray technique. The prepared FGM coated plate was characterized by the hardness test, density test, three-point bending test and thermal shock test to prove the improvement of the bending strength of the aluminum plate. The morphology of the FGM coating was also examined by scanning electron microscope image. (paper)

[en] Graphical abstract: Multi-walled carbon nanotubes paste electrode has been successfully used for the oxidation of FUR in BR buffer solution (pH = 5.0). Based on the study, influence of several physico-chemical parameters like potential scan rate, pH and concentration were investigated. Highlights: ► CNTPE has been successfully used for the electro-oxidation of FUR. ► Cyclic and differential-pulse voltammetric techniques are used. ► Effects of E_pa, I_pa and k⁰ have been discussed. ► DPV method was developed for the determination of FUR. - Abstract: Electrochemical oxidation of loop diuretic furosemide (4-chloro-2-(furan-2-ylmethylamino)-5-sulfamoylbenzoic acid) was studied in 5.0 pH with 0.04 M Britton–Robinson buffer as supporting electrolyte at 25 ± 0.1 °C at a multi-walled carbon nanotubes-paraffin oil paste electrode (CNTPE) using cyclic and differential-pulse voltammetric (DPV) techniques. The electrochemical process was observed to be adsorption controlled, irreversible and involving two-electron oxidation. Effects of anodic peak potential (E_pa), anodic peak current (I_pa) and heterogeneous rate constant (k⁰) have been discussed. Under optimal conditions, the peak current was proportional to furosemide concentration in the range of 8.0 × 10⁻⁶ to 2.0 × 10⁻⁴ M with a detection limit of 2.9 × 10⁻⁷ M by differential pulse voltammetry. A differential pulse voltammetric method with good precision and accuracy was developed for the determination of furosemide in pharmaceutical formulations and urine as a real sample.

[en] In the present study, an attempt has been made to evaluate contribution of the Gold Nano-Particles (AuNPs) in standard Fricke chemical dosimetry solution during Gamma irradiation. Different concentrations of purified AuNPs were added to Fricke solution and absorbance was measured before and after exposing to graded doses of Gamma rays. Absorbance of un-irradiated Fricke solution with and without AuNPs was also measured and compared. Absorption spectra with peak at 303nm indicate no chemical reaction upon adding AuNPs in to Fricke solution. Further, peak observed around 555 nm clearly indicates the stability of the Nano-Particles (NPs) in Fricke solution. For a given dose, a significant increase observed in the optical intensity for Fricke solution with AuNPs, as compared to Fricke solution alone, confirms the effectiveness of AuNPs during irradiation. Study also indicates that concentration of AuNPs can also influence the absorbance significantly. (author)

[en] A versatile and automated monitoring environment has been developed to complement the data acquisition and trigger systems employed in the Kolar Gold Fields nucleon decay experiment. This article discusses the technical aspects of this environment in detail as well as the various facilities offered by it, in terms of detector maintenance and event data calibration. Novel design features, operating characteristics and capabilities of different monitors are highlighted. (orig.)

[en] We have adapted a microcomputer based data acquisition system using the concept of parallel processing. The active detector components consisting of 3800 proportional counters, are read out by a network of nine Z-80 based microprocessor modules. A look-up table concept for generating various trigger schemes has also been implemented. (orig.)

[en] Highlights: • Friction stud welding of AA 6063 and AISI 1030 was done successfully. • Ultrasonic evaluation of interfacial properties. • EDX analysis confirms intermetallic compound (FeAl) in the interfacial region. - Abstract: Friction stud welding is a promising technique in many applications related to oil and gas industries. It is used to attach grating to offshore oil platforms in areas where arc welding is not permitted because of the risk of causing a fire or explosion. Attachment of anodes inside seawater discharge pipelines in a gas processing plant is performed by this process. This solid state joining process permits metal combinations such as welding of aluminum studs to steel which would be problematic with arc welding because of the formation of thick and brittle inter-metallic compounds. In the present work, AA 6063 is joined to AISI 1030 steel using friction stud welding machine. Properties that are of interest to manufacturing applications such as Young’s modulus, longitudinal velocity, bulk modulus and shear modulus are evaluated by means of an ultrasonic flaw detector. At the interface of the joint, there is an increase of 4.4%, 1.8%, 1.15% and 4.42% is observed for the properties Young’s modulus, longitudinal velocity, bulk modulus and shear modulus respectively. This is due to the formation of intermetallic compound and increase in hardness at the interfacial region. Energy Dispersive X-ray analysis confirms the presence of FeAl as the intermetallic compound. Scanning Electron Microscope evaluation shows the presence of an unbound zone at the center of the inner region which is due to the minimum rotational speed and low axial load experienced at that point. In the unbound zone, there is an incomplete bond between dissimilar metals and it is detrimental to joint strength. Optimum value of friction time and usage of pure aluminum interlayer during the friction stud welding process hinders the formation of unbound zone and enhances the quality of AA 6063/AISI 1030 joints. The tensile strength of AA 6063/AISI 1030 joint was found to be 36.64% and 78.15% lower than that of AA 6063 and AISI 1030 respectively. Reasons for lower joint strength are attributed to low frictional pressure, non-optimal rotational speed and friction time, improper mechanical mixing, presence of oxide layer and formation of brittle intermetallic compound at the joint interface

[en] Quantification of bioactive compounds via electrochemical methods is a topic of great interest over the past decades, due to its versatility and accuracy of estimation at the trace level. In the present investigation, an antihistamine drug Cetirizine (CTZ) was quantified by the electrochemical technique using carbon sensor fabricated with coalesced ruthenium-doped titanium dioxide (Ru-TiO₂) nanoparticles and multi-walled carbon nanotubes (MWCNTs). The fabricated nanocomposite sensor offered four-folds augmented oxidation peak for CTZ compared to the nascent carbon sensor in pH 6.0 media. Electrochemical analysis of CTZ was performed by voltammetry techniques such as cyclic voltammetry (CV), square wave voltammetry (SWV) to estimate heterogeneous rate constant, a number of proton-electron transferred in the oxidation response. The method developed showed CTZ electrooxidation with a low detection limit value of 3.10 nM and hence, the method was used to evaluate CTZ in human urine as well as from the pharmaceutical formulations. (paper)

[en] Highlights: • Electrochemical behavior of thiosalicylic acid (TSA) was illustrated by using CV and SWV. • For the first time the γ-Fe₂O₃/clay-CPE was fabricated and used for TSA determination. • SEM, XRD and AFM analysis were utilized to study the modifier characteristics. • The sensor displayed high sensitivity with detection limit 5.7 nM. • This technique was applicable in the determination of TSA in spiked human urine samples. In the current work, the fabricated novel electrode achieved an enhanced sensitivity and electrocatalytic behavior towards thiosalicylic acid (TSA) detection, by coating γ-Fe₂O₃ nanoparticles and bentonite clay composite on the carbon paste matrix. The surface characteristics of modifier were studied by utilizing scanning electron microscope (SEM) and X-ray diffractometer (XRD) followed by atomic force microscopy (AFM). The electrooxidation of TSA was studied at γ-Fe₂O₃-CPE, clay-CPE and γ-Fe₂O₃/clay-CPE by cyclic voltammetry (CV) and square wave voltammetric (SWV) techniques. The γ-Fe₂O₃/clay-CPE sensitivity for TSA has shown significant augmentation compared to the other electrodes. In addition, the modified electrode processes some unique characteristics, such as appropriate charge transfer rate, enduring stability, exceptional reproducibility and antifouling effects. The parameters affecting the peak enhancement such as pH, modifier amount, accumulation time, scan rate and concentration impacts were studied. The concentration of TSA was determined by the electrode in a wide concentration range of about 0.05 μM–0.5 μM with LOD value of 5.7 nM. The practical electroanalytical application was conducted by carrying out quantification of TSA in human urine samples.