We consider a model describing Bose-Josephson junction (BJJ) coupled to a single bosonic mode exhibiting quantum phase transition (QPT). Onset of chaos above QPT is observed from semiclassical ...dynamics as well from spectral statistics. Based on entanglement entropy, we analyze the ergodic behavior of eigenstates with increasing energy density which also reveals the influence of dynamical steady state known as π-mode on it. We identify the imprint of unstable π-oscillation as many body quantum scar (MBQS), which leads to the deviation from ergodicity and quantify the degree of scarring. Persistence of phase coherence in nonequilibrium dynamics of such initial state corresponding to the π -mode is an observable signature of MBQS which has relevance in experiments on BJJ.
The development of various metal oxide semiconductor materials has resulted in better performance of the gas sensors in terms of selectivity, sensitivity, and response time. Different types of ...nanostructured materials, i.e., 2D materials, carbon nanotubes, and metal oxides, are used in the gas sensing applications. Generally, the metal oxide-based gas sensor operates at higher temperature to activate the adsorption process between the material surface and the target gas. The higher operating temperature of the gas sensor leads to more power consumption and produces defects in the grain boundary of metal oxide. To improve the selectivity and minimize the power consumption, nanoparticle-based p-type semiconductor materials are being developed. P-type metal oxide-based semiconductor materials have the ability to produce a hole accumulation layer which can chemisorb the oxygen molecules of higher concentration and these materials are not affected by humidity. The structure of p-type nanomaterial-based gas sensor depends upon the fabrication techniques which can affect the sensing properties of semiconductor materials. The hole accumulation layer is also known as conduction layer which is developed in the outer shell of p-type semiconductor material and the sensing mechanism is controlled by grain boundaries which is different from the n-type semiconductor material. This paper reviews the preparation methods, morphological analysis, and sensing mechanisms of nanomaterial-based p-type metal oxide-based gas sensors.
•Anovel hybridnanostructure (Ag-Cu2O@TNTs) highly sensitive cholesterol biosensor was fabricated.•The biosensor showed great sensitivity, good stability, and selectivity along with a low detection ...limit.•The optimization of process parameters, including pH, and temperature was successfully conducted during the electrochemical sensing procedures.•The developed electrode accurately detected cholesterol in human blood serum.
We developed a highly sensitive non-enzymatic biosensor based on hybrid Ag-Cu2O@TNTs nanostructure aggregate for the detection of cholesterol. A facile anodization process on a thin titanium alloy (Ti6Al4V) plate was achieved to deposit TiO2 nanotubes (TNTs). Subsequently, TNTs was decorated with Cu2O nanomaterials (NM) using wet chemical bath deposition (CBD) technique. The electro-deposition of silver (Ag) nanoparticles on Cu2O@TNTs hybrid aggregate produced high electroactive surface area which enhanced the electron transfer rate. The structure of Ag-Cu2O@TNTs was examined using X-ray diffraction (XRD), transmission emission microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). Cyclic voltammetry (CV) and amperometry techniques were utilized to study the electrochemical behaviour of nanostructures. The hybrid nanostructure demonstrated great sensitivity (12140.06 μAmM−1cm−2) compared to pure TNTs and Cu2O@TNTs with low detection limit (0.057 mM) and fast response. This study highlights exciting potential of nanocomposites in advancement of reproducible and selective biosensor applications.
In the present investigation, CoCrCuFeNi based multicomponent nano-scale Y2O3–Ti dispersed oxide dispersion strengthened (ODS) alloys were prepared by mechanical alloying followed by spark plasma ...sintering (SPS) at three different temperatures (900 °C, 1000 °C and 1100 °C). The microstructures of the as processed SPS samples primarily consist of a combination of F1 and F2 based FCC phases in the matrix in addition to a minor amount of second (Co14·2Cr2·7Y2) phase. Further TEM analysis indicates bimodal grain size distribution with an increasing trend in grain size from 0.110 μm to 0.883 μm with an increase in sintering temperature. The best combination of ultimate compressive strength (1555 MPa) and hardness (468 HV) of the SPS processed bulk ODS-HEA has been obtained when sintered at 1000 °C. The contribution in yield strength has been estimated using three strengthening mechanisms and the Orowan strengthening model is the most dominating strengthening mechanism in the present ODS-HEA.
•CoCrCuFeNi −1 wt. % of Y2O3–Ti based ODS multicomponent alloy were prepared through a combined MA and SPS approach.•The ODS-HEA alloy shows the highest compressive strength and hardness values, which was obtained for sintered at 1000 °C.•The contribution of the Orowan strengthening model in the enhancement of yield strength is most dominant.
Medical attention is needed to overcome the haemocompatibility of Ti alloy implants, where nanotechnology is one of the concerned subjects. In the present study, a combined electrochemical approach ...was employed to access
in-vitro
studies on Ti6Al4V alloy (Ti64). A higher bath temperature with specific field potential was used for the formation of nanotubes.
In-vitro
haemocompatibility (platelet adhesion (PA) and staining) study had been conducted on TiO
2
nanotube composite samples, which were derived by varying electrochemical parameters 51 nm (high pore density), 61 nm (moderate pore density), and 72 nm (lowest pore density) with divergent topography in fresh electrolytes. Platelet adhesion and composition were observed under FE-SEM and EDS. Image J software was used to analyse the various topographies. Haemolysis rate (HR) and PA tests were conducted to evaluate biocompatibility. Topography of 61 and 72 nm TiO
2
nanotube (TNT) had shown better HR. Additionally, the MTT assay had shown higher cell viability. Besides, fluorescence microscopy had revealed maximum staining of adhered platelets on 51 nm TNT, obtained with the highest pore density.
In this research, Y2O3-reinforced (0, 1, 2, 3 wt%) AlCoCrFeNi high entropy alloys (HEAs) were synthesized using mechanical alloying (MA) and spark plasma sintering (SPS) technique. After 40 h of ...milling, the phase aggregate combines a body centred cubic (BCC) solid solution structure and face centred cubic (FCC) for all the four alloys and minor presence of Al4FeO12Y3 garnet phase in the alloys containing Yttria (1–3 wt%). After the consolidation by SPS method at 1000 °C, σ phase was also observed. Meanwhile, the Garnet phase was retained during consolidation. With the help of X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis, it was observed that the inclusion of Yttria particles has a constricting outcome on the grain growth of alloy during SPS. The average grain size measured varies from 203 nm to 151 nm for 0 and 3 wt% dispersed alloy respectively. The present Yttria dispersed alloys show improved hardness and yield strength of 879 ± 4 HV and 1032 ± 11 MPa respectively for 3 wt% Yttria dispersion. The novelty of Yttria dispersed alloys resides in the microstructure containing the Al4FeO12Y3 particles with uniform distribution.
Cholesterol and triglycerides are crucial essential materials in human anatomy for ensuring the stability and fluidity of cell membranes, as well as operating as a precursor for the formation of ...vital compounds such as hormones in the body, bile acids, and vitamin D. Although once the total cholesterol levels exceed some critical value, particularly in the form of the low-density lipoprotein, it can readily create massive blockage in the wall of the arteries resulting in the complications arising from coronary or ischemic heart disease and peripheral arterial disease. An ideal biocompatible electrochemical cholesterol biosensor should satisfy the criterions concerning with detection in the wide linear range of concentration, a low detection limit, superior sensitivity, a fast reaction time, and a decent reproducibility. The current review provides a brief legacy of a broad range of micro/nanostructured metal oxides (MOx) and their subsequent use for improving the analytical performance of electrochemical cholesterol biosensors over the last few decades. Pristine or hybrid metal oxides with micro/nanostructure morphology arising from ZnO, CuO
2
, CeO
2
, MnO
2
, TiO
2
, Co
2
O
3
, etc. show great promises as biosensors owing to their excellent electrical, electrochemical, and biocompatible characteristics. The enormous surface area of nanostructured-based MOx materials could offer an enhanced matrix for the immobilization of preferred enzyme, resulting in improved enzyme absorption per unit mass of constituents. In addition to highlighting recent achievements in this field, the inherent gaps associated with real-time applications of micro/nanostructured metal oxides (MOx) electrochemical biosensors, as well as their future prospects in clinical applications.
Titania nanotubes fabricated over grade V medical Ti6Al4V alloys (Ti64) in fresh pure electrolytes EG and EGD in order to meet the requirements of a significant implant material for biomedical ...application. Wettability and contact angle hysteresis is a matter of concern for the nano-textured surface that needs to be understand for its biological activity in correlation to surface properties. Therefore, titania nanotubes have been fabricated in two different electrolytes to understand the wetting behaviour. The present study shows an increment in the wettability from hydrophilic to hydrophobic compared to emery-polished Ti-Alloy. Topographical change of TiO
2
nanotubes has also been observed in two different electrolytes. Additionally, change in the wall thickness has been identified in the TiO
2
nano fabricated on fresh electrolytes.
•We report a simple route for the synthesis of pure and Sn-doped ZnO nanostructures.•A possible formation mechanism of the 1D-ZnO nanostructures has been proposed.•These nanostructured sensors show ...great promise for detecting NH3 vapors.•Our synthesized materials exhibit outstanding repeatability and reproducibility.
Randomly oriented Sn-doped ZnO (Zn1−xSnxO) nanofibers have been synthesized by a facile evaporation and re-condensation technique using metallic Sn and Zn as precursors in Ar–2% O2 atmosphere at 850°C on Si substrates. The dimension of the Zn1−xSnxO nanofibers ranges from 100nm to 200nm in diameters and lengths up to few mm. The XRD patterns reveal a set of distinct diffraction peaks indexed as the wurtzite hexagonal ZnO phase. The growth mechanism is dominated by a catalyst-free vapor solid process and the preferred growth direction of Sn-doped ZnO nanofibers is along the 0001 direction. The NH3 sensing properties of the as-deposited nanostructures are investigated for different vapor concentrations (10, 25, 50, 100 and 200ppm) and working temperatures (200, 250, 300, 350°C). Zn1−xSnxO nanofibers are found to possess better sensitivity toward the ammonia vapor as compared to pristine or undoped ZnO nanowires at identical experimental conditions. The gas sensing mechanism of the nanostructures has been discussed in detail. The high sensitivity and dynamic reproducibility of these sensor materials reveal that this composition and morphology can be applied to fabricate sensing devices for detecting ammonia vapor at low to medium concentration range.
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