Performance Optimization of a Large Geometry High Resolution-Secondary Ion Mass Spectrometer (HR-SIMS) for High Precision Measurements of Oxygen Isotopic Composition (δO) and U-Pb Geochronology in Zircon.

A large geometry high resolution secondary ion mass spectrometer (HR-SIMS) has been established as a part of the National Geochronology Facility (NGF) at Inter-University Accelerator Centre (IUAC), New Delhi. The performance of the instrument related to high spatial resolution, high mass resolving power (MRP), sensitivity of the instrument to measure low abundant isotopes, and sensitivity of the instrument for Pb signal under different conditions are optimized and presented in this paper. We report the precision of the order of ~ 0.

Unraveling the Augmented Field Emission Performance of Molybdenum Disulfide-Praseodymium Sulfide (MoS@PrS) Heterostructure: A Combined Experimental and First Principles-Based Study.

The molybdenum disulfide-praseodymium sulfide (MoS-PrS) heterojunctions are optimally synthesized through a sophisticated three-step procedure. Initially, MoS rods are synthesized using the micellar route followed by a solid-state reaction, forming well-defined structures. Subsequently, PrS nanoparticles are synthesized using the same method.

Study on damage of GdO-CeO under electronic energy loss: comparison between bulk-like and nanostructure.

To understand the physical phenomena responsible for radiation damage of the materials used in nuclear reactors, and thus study their operation life and/or efficiency, it is required to simulate the conditions by exposing the materials to energetic ions. Ceria (CeO) has been proposed as one of the inert matrices for the transmutation of minor actinides in the futuristic inert matrix fuel (IMF) concept. The inert matrix should also contain burnable poison to compensate for the initial reactivity of fuel.

Hydrogeochemical Processes Governing Uranium Mobility: Inferences from the Anthropogenically Disturbed, Semi-arid Region of India.

Khetri Copper Belt, Rajasthan, is anthropogenically active and geologically belongs to the Delhi super-group. A study was designed to understand the geochemical processes controlling the elemental mobility in the groundwater. Sampling sites were divided into three zones, i.

Design and development of a compact ion implanter and plasma diagnosis facility based on a 2.45 GHz microwave ion source.

A project on developing a 2.45 GHz microwave ion source based compact ion implanter and plasma diagnostic facility has been taken up by the Central University of Punjab, Bathinda. It consists of a double-wall ECR plasma cavity, a four-step ridge waveguide, an extraction system, and an experimental beam chamber.

Local structure investigation of Co-Fe-Si-B ribbons by extended X-ray absorption fine-structure spectroscopy.

In the present work, extended X-ray absorption fine-structure (EXAFS) investigations of CoFeSiB (x = 3, 5, 7) glassy ribbons were performed at the Co K-edge. The magnitude of the first peak of the Fourier transforms of the EXAFS signals is found to increase monotonically with increasing Si concentrations indicating the formation of the localized ordered structure at the atomic scale. The Co-Si coordination number (CN) increases at the expense of the CN of Co/Fe.

Curie temperature engineering in a novel 2D analog of iron ore (hematene) strain.

As a newly exfoliated magnetic 2D material from hematite, hematene is the most far-reaching ultrathin magnetic indirect bandgap semiconductor. We have carried out a detailed structural analysis of hematene prefacing strain by means of first-principles calculations based on density functional theory (DFT). Hematene in the pristine form emerges out to be a magnetic semiconductor with a bandgap of 1.

Ion beam modified TiO nanotubular bio-interface for electrochemical detection of L-tyrosine towards smart bandage application.

One of the common complications diagnosed in Diabetes Mellitus (DM) patients is Diabetic Foot Ulcers (DFUs). It is a condition wherein the deep tissues located in the lower limb undergo inflammation and infection due to neurological abnormalities (neuropathy) and various degrees of vascular diseases (angiopathy). The concentration of l-tyrosine (Tyr) rises abruptly in DFUs, and therefore may be used as an indicator for early monitoring of the patient's condition during the onset of diabetic foot disease.

Medium Energy Carbon and Nitrogen Ion Beam Induced Modifications in Charge Transport, Structural and Optical Properties of Ni/Pd/n-GaN Schottky Barrier Diodes.

The irradiation effects of carbon and nitrogen medium energy ions (MEI) on charge transport, structural and optical properties of Ni/Pd/n-GaN Schottky barrier diodes are reported. The devices are exposed to 600 keV C and 650 keV N ions in the fluence range of 1 × 10 to 1 × 10 ions cm. The SRIM/TRIM simulations provide quantitative estimations of damage created along the trajectories of ion beams in the device profile.

Enhanced visible light photodegradation activity of RhB/MB from aqueous solution using nanosized novel Fe-Cd co-modified ZnO.

A series of novel Fe-Cd co-doped ZnO nanoparticle based photocatalysts are successfully synthesized by sol-gel route and characterized using scanning electron microscopy (SEM), energy dispersive X-ray emission (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) techniques. The photocatalytic activity of ZnO nanoparticles doped with various atomic weight fraction of Fe and Cd has been investigated under visible light irradiation using the Methylene Blue and Rhodamine B dye in aqueous solution. The FeCd (2%):ZnO (ZFC-1) exhibit the highest photocatalytic activity in terms of rate constant as K = 0.

A fast response, low heat generating activation method for LHe level sensors.

A superconducting liquid helium (LHe) level sensor of length 300 mm has been fabricated based on the principle of differential heat transfer characteristic in helium gas compared to that in liquid. The sensor wire used has a diameter of 38 μm, and the wire was obtained from a pack of multifilament wires. A full thermo-electrical characterisation of the sensor was carried out in a dedicated setup.

Facile Synthesis of Semiconducting Ultrathin Layer of Molybdenum Disulfide.

In this paper, we have reported a simple and efficient method for the synthesis of uniform, highly conducting single or few layer molybdenum disulfide (MoS2) on large scale. Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM) have been used for the confirmation of mono or few layered nature of the as-synthesized MoS2 sheets. X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD) and Raman Spectroscopy have also been used to study the elemental, phase, and molecular composition of the sample.

Complex coacervation in charge complementary biopolymers: Electrostatic versus surface patch binding.

In this review, a number of systems are described to demonstrate the effect of polyelectrolyte chain stiffness (persistence length) on the coacervation phenomena, after we briefly review the field. We consider two specific types of complexation/coacervation: in the first type, DNA is used as a fixed substrate binding to flexible polyions such as gelatin A, bovine serum albumin and chitosan (large persistence length polyelectrolyte binding to low persistence length biopolymer), and in the second case, different substrates such as gelatin A, bovine serum albumin, and chitosan were made to bind to a polyion gelatin B (low persistence length substrate binding to comparable persistence length polyion). Polyelectrolyte chain flexibility was found to have remarkable effect on the polyelectrolyte-protein complex coacervation.

Experimental helium liquefier with a GM cryocooler.

A helium liquefier has been developed with a Gifford-McMahon cryocooler using the cold enthalpy available at the first stage, the inter-stage, and the second stage of the cryocooler. Most of the enthalpy of the helium gas at 300 K is absorbed in the first stage by a coaxial heat exchanger and inter-stage region of the cryocooler. Pre-cooled helium gas is liquefied at the second stage heat exchanger where the final cooldown and condensation happens.

Mesoporous polyaniline nanofiber decorated graphene micro-flowers for enzyme-less cholesterol biosensors.

In the present work, we have studied a nanocomposite of polyaniline nanofiber-graphene microflowers (PANInf-GMF), prepared by an in situ rapid mixing polymerization method. The structural and morphological studies of the nanocomposite (PANInf-GMF) were carried out by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) and Raman spectroscopy. The mesoporous, nanofibrous and microflower structures were observed by scanning electron microscopy.

Topography evolution of 500 keV Ar(4+) ion beam irradiated InP(100) surfaces - formation of self-organized In-rich nano-dots and scaling laws.

We report the formation of self-organized nano-dots on the surface of InP(100) upon irradiating it with a 500 keV Ar(4+) ion beam. The irradiation was carried out at an angle of 25° with respect to the normal at the surface with 5 different fluences ranging from 1.0 × 10(15) to 1.

Influence of Structure, Charge, and Concentration on the Pectin-Calcium-Surfactant Complexes.

Polymer-surfactant complex formation of pectin with different types of surfactants, cationic (cetyltrimethylammonium bromide, CTAB and dodecyl trimethylammonium bromide, DTAB), anionic (sodium dodecyl sulfate, SDS), and neutral (Triton X-100, TX-100), was investigated at room temperature in the presence and absence of cross-linker calcium chloride using light scattering, zeta potential, rheology, and UV-vis spectroscopic measurements where the surfactant concentration was maintained below their critical micellar concentration (CMC). Results indicated that the interaction of cationic surfactant with pectin in the presence and absence of calcium chloride was much stronger compared to anionic and neutral surfactants. The neutral surfactant showed identifiable interaction despite the absence of any charged headgroup, while anionic surfactant showed feeble or very weak interaction with the polymer.

Characterization of microstructure, viscoelasticity, heterogeneity and ergodicity in pectin-laponite-CTAB-calcium nanocomposite hydrogels.

In order to customize the viscoelastic properties of pectin gels, it is necessary to work on a composite platform. Herein, the gelation kinetics, and viscoelastic characterization of anionic polysaccharide pectin dispersion prepared in presence of nanoclay laponite are reported using dynamic light scattering and rheology measurements. The ratio Rg/Rh (Rg and Rh are radius of gyration and hydrodynamic radius respectively) determined from light scattering data revealed the presence of random coils of pectin chains inside the gel matrix.

Internal structure and thermo-viscoelastic properties of agar ionogels.

Ionic liquids (IL) can alter the physical properties of agar hydrogels. Rheology studies show that gels with wide range of storage moduli (gel strength) G0 values ranging from 1 to 20 KPa could be made in imidazolium based IL solutions where the IL concentration may not exceed 5% (w/v). Gelation and gel melting temperatures (tgel and Tm) could be altered by as much as ≈ 10 °C.

Interaction of Globular Plasma Proteins with Water-Soluble CdSe Quantum Dots.

The interactions between water-soluble semiconductor quantum dots [hydrophilic 3-mercaptopropionic acid (MPA)-coated CdSe] and three globular plasma proteins, namely, bovine serum albumin (BSA), β-lactoglobulin (β-Lg) and human serum albumin (HSA), are investigated. Acidic residues of protein molecules form electrostatic interactions with these quantum dots (QDs). To determine the stoichiometry of proteins bound to QDs, we used dynamic light scattering (DLS) and zeta potential techniques.

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses.

We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt-Si thin film with medium-energy neon ions at constant fluence (1.0 × 10(17) ions/cm(2)). Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (S e/S n) from 1 to 10.