Quantum Zeno Effect (QZE), a phenomenon where frequent measurements can inhibit the evolution of a quantum system, has garnered significant attention since its discovery by Misra and Sudarshan in 1977. This effect could advance quantum technologies, including suppressing Hawking radiation, enhancing noise sensors, and improving quantum communication and computing. In this work, we investigate the QZE in an asymmetric nonlinear coupler consisting of two distinct channel waveguides: a linear waveguide and a waveguide with second-order nonlinearity. Each waveguide supports a single light mode from a coherent laser source. The nonlinear interaction in the nonlinear waveguide produces second harmonic generation (SHG), doubling the frequency of the input mode to enhance quantum effects. In this setup, the linear waveguide serves as a probe, while the nonlinear waveguide with SHG acts as the primary system. The nonlinear coupler, with its simple structure and versatile configuration, offers an ideal platform for studying the QZE. Unlike the short-length approximation method or the analytical perturbative (AP) method, which approximate quantum system dynamics using a truncated Baker-Campbell-Hausdorff (BCH) formula for computational feasibility-thereby restricting their accuracy, especially in systems with strong interactions-the positive-P representation offers a more precise approach. This phase-space method transforms the system's Hamiltonian into a master equation for the density matrix without requiring truncation, enabling significantly more accurate analysis of the quantum dynamics, even over extended evolution distances. Our findings reveal that the QZE is strongly influenced by the nonlinear coupling magnitude, evanescent coupling strength, and frequency mismatch. These results offer a precise theoretical framework to guide practical applications of the QZE and lay the groundwork for exploring the effect in more complex quantum systems.
The present work investigates the variability of the meridional component of thermospheric winds during 189 days of moderate and high solar activity across the period of 2011-2013. In this study, the characteristics of wind velocity based on local time, season, and solar activity were examined to understand neutral dynamics of the thermosphere over Southeast Asia. The winds velocity was determined from 630nm airglow measured with Fabry-Perot interferometers located at low-latitude stations in Chiang Mai, Thailand (MLAT: 9.4 degrees N, MLON: 172.0 degrees E) and Kototabang, Indonesia (MLAT: 9.5 degrees S, MLON: 172.9 degrees E). Our comparison of the meridional (Vn) and zonal (Ve) component of winds during this time showed distinct differences between the two, with stronger Ve (60-110 m/s) primarily flowing eastward, whereas Ve was weaker (5-60 m/s) with reversals in both poleward and equatorward flow throughout the nighttime. Additionally, our further analysis of Vn reported that winds were stronger and more poleward during winter and summer seasons (75-115 m/s) compared to near equinox months (similar to 50-70 m/s), with velocities reaching peak amplitude earlier in the evening sector (1100-1300 UT) rather than at midnight hours (1600-2200 UT). In this study, there was a slight dependency on solar activity observed, resulting in more variability and reduced wind velocities of up to +/- 5-20 m/s. Fully understanding the relationship between meridional winds and solar activity in this region requires future studies that encompass a wider range of solar activity levels, including low, moderate, and high conditions. These observational results provide important constraints for improving empirical models such as the Horizontal Wind Model (HWM), particularly for low-latitude regions. Enhanced model accuracy can support better space weather forecasting and ionospheric prediction across Southeast Asia.
Gel polymer electrolytes (GPEs) have become a critical component in electrochemical devices such as batteries, supercapacitors, etc. due to their high ionic conductivity, mechanical flexibility, and enhanced safety. In this work, fish skin gelatine (FG) incorporated with varying concentrations of ammonium nitrate (NH4NO3 ) was successfully fabricated using the solution casting technique. Fourier transform infrared (FTIR) spectroscopy confirmed the interaction between FG and NH4NO3 salt. The optimum conductivity, (6.22 +/- 0.16 x 10(-3)) S cm(-1), was achieved for the GPE incorporating 15 wt.% NH4NO3 (GFG15), exhibiting the lowest crystallite size of 1.195 nm. The ion transference number (t(ion)) of GFG15 was determined to be 0.98, signifying its role as a predominantly ionic conductor. Linear sweep voltammetry (LSV) demonstrated the GFG15's suitability for application in a carbon-based symmetric electric double layer capacitor (EDLC). The highest specific capacitance (C-sp) of the electrode was recorded as 98.23 F g(-1) and 74.24 F g(-1) from cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) studies, respectively.
The present work reports the performance of FeSe(2)and Co(3)Se(4 )electrode for supercapacitor. The samples were synthesized via a two-step hydrothermal technique. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and N2 adsorption-desorption technique were implemented as the analytical approaches for material characterizations. To measure the electrochemical performance of FeSe(2 )and Co(3)Se(4 )electrode, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) have been introduced. Co(3)Se(4)electrode depicts a better electrochemical performance in terms of specific capacitance (C-sp) value and charge transfer resistance (R-ct), as compared to FeSe(2 )electrode. Co(3)Se(4 )electrode achieves a maximum C(sp )value of 274.65 F g(-1) at 1 A g(-1), investigated in a 6 M KOH electrolyte solution. The performance superiority can be attributed to the larger surface area, higher porosity and lower R-ct.
Understanding heat, water, and vapor transport in unsaturated soils is crucial for various applications, including agriculture, engineering, and environmental sciences. While existing models, such as those derived from de Vries [1] and Philip and de Vries [2], effectively describe these processes, they struggle with accurately predicting water movement in dry soil regions. Discrepancies in the vapor enhancement factor between heat and mass balance equations and experimental observation (e.g., Heitman et al. [19]; Goh [18]) suggest fundamental misalignments, leading to overestimated heat flux and underestimated water flux. This study re-derives the heat balance equation to identify and address these limitations. Key findings indicate that temperature-dependent latent heat of vaporization should be reconsidered, and the unsaturated hydraulic conductivity model by Fayer and Simmons [23] improves dry-region predictions. Additionally, the vapor volume expansion advection model by Goh and Noborio [31] offers an alternative to the vapor enhancement factor. These refinements could enhance the consistency between heat and mass transport models, improving the accuracy of soil moisture and temperature simulations. The equation improvement provides a stronger theoretical foundation for coupled heat-water transport modeling, with implications for soil management, climate modeling, and subsurface engineering.
Solid polymer electrolytes (SPEs) have garnered significant attention for their potential use in energy storage devices, owing to their safety, mechanical flexibility, and stability. Despite these advantages, enhancing their amorphous structure and electrochemical performance remains essential to fully unlock the commercial potential of SPEs. SPEs based on a chitosan-dextran polymer blend were developed for use in electrochemical double-layer capacitors (EDLCs). The polymer matrix was plasticized with honey to enhance its flexibility and ionic conductivity. Ammonium nitrate (NH4NO3) was used as the charge carrier, facilitating ion transport within the polymer matrix. The hydrogen bonding interactions between the materials were studied using Fourier transform infrared spectroscopy (FTIR). The inclusion of 10 wt.% honey in the Ch and Dx polymers successfully reduced the crystallite size and lowered the glass transition temperature (T-g) of the polymers. The optimized SPE formulation demonstrated promising ionic conductivity and stability, making it a suitable candidate for EDLC applications.
Rubber is crucial for economic development and poverty alleviation in countries like the Philippines. Despite being a major producer, the Philippines struggles with low export values due to quality issues in natural rubber. While other countries have shown that electron beam (EB) irradiation can improve natural rubber latex (NRL), there's limited research on its effects on Philippine-sourced NRL. This study examines the impact of EB irradiation on the mechanical properties of NRL from Zamboanga Sibugay, Philippines. The study used high ammonia (HA) concentrated NRL, irradiated in both liquid (ILN) and solid (ISN) forms at the PNRI Electron Beam Irradiation Facility. EB irradiation improved the mechanical properties of NRL by increasing crosslinking within the tested dose range. Both ILN and ISN samples showed a decrease in swelling ratio and an increase in gel fraction, indicating successful crosslinking. Tensile strength increased significantly: from 1.21 MPa to 8.42 MPa for ILN and from 1.56 MPa to 3.99 MPa for ISN. Stress at 300% elongation also rose, and elongation at break decreased with higher EB doses. ILN showed greater mechanical improvement than ISN due to water radiolysis. Additionally, EB irradiation enhanced the thermal stability of NRL, confirmed by changes in FTIR and Raman spectra. Despite these improvements, both raw and irradiated NRL did not meet the minimum tensile property standards for most NRL products, indicating the need for further research.
Large amplitude ion-acoustic slow mode solitons and small amplitude slow mode double layers are studied for a collisionless, unmagnetized model plasma composed of warm positive ions, warm negative ions, warm positrons and two-temperature non-isothermal electrons by the Sagdeev pseudopotential method. This method is used to investigate the ion thermal effects on the slow mode solitary wave propagation. Considering all plasma constituents as adiabatic fluids, the basic set of normalized fluid equations are reduced finally to "dispersion relation" for obtaining the phase velocities of slow (V-S) and Fast (V-F) modes.
The material properties are important to determine their potential application in industries. Hence, we developed a computerised system to measure the material properties of each layer for multilayered materials in this study. The system employs the pulse echo immersion technique to determine five material properties of each layer for three layer materials; longitudinal velocity, acoustic impedance, Young's modulus, shear modulus and bulk modulus. It consists of a pulser/receiver generator, an ultrasonic transducer acts as both a transmitter and a receiver, a digital oscilloscope, and a personal computer with a custom-developed program. The user interface of the program comprises of two parts; (1) signal acquisition and display panel, and (2) signal analysis panel. The accuracy of the developed system was validated using three multilayered poly(methyl methacrylate) samples of different thicknesses and Olympus Panametrics NDT transducers with 10 MHz center of frequencies. The findings indicated that the system produced accurate results, within a 6.54% error compared to reference values. The system offers the spontaneous results display and user-friendly interface for novice users.
The therapeutic promise of low-level laser therapy (LLLT) has garnered significant attention as a non-invasive approach with diverse applications. LLLT mainly employs low-power lasers to stimulate healing and alleviate pain. LLLT is commonly used for wound healing, hair loss treatment, neurological disorders, skin conditions, and in sports medicine. This research investigates the effects of successive lowlevel laser exposure, using a 532 nm green laser, on neuroblastoma SH-SY5Y cells cultured in vitro, with a particular focus on photobiostimulation. In the experimental setup, SH-SY5Y cells were seeded in a 96-well plate, subjected to laser treatment, and evaluated for cell viability using the MTT-assay technique. Subsequently, the seeded cells were exposed to controlled doses of a continuous 532 nm green Diode-Pumped Solid-State laser having a beam area of approximately 0.20cm2, with varying combinations of exposure durations (5, 10, and 15 minutes) and power levels (60, 120, and 180 mW) at 4cm distance from the laser beam to assess the potential effects of LLLT on these cells. The outcomes of this study demonstrated that the treated cells exhibited their highest average cell viability of 122% at the180 mW laser power exposure during the 15 minutes exposure time. These results greater than the control groups, indicates improved viability post-treatment. Conversely, some cells displayed lower viability percentages than the control groups, the lowest observed average cells viability was 87% with an exposure power of 120 mW and exposure time of 5 min. These results suggest less favorable survival outcomes. The higher cell viabilities relative to the control groups indicate that the treatment is triggering photobiostimulation, while values below the control group indicate photobioinhibition. These results underscore the overall influence of green laser exposure and low-level laser irradiation in promoting cell viability, proliferation, and metabolic activity within SH-SY5Y cells. These findings carry implications for future strategies in the treatment of neuroblastoma and related neurological disorders using non-invasive laser-based approaches.
Commercial grade aluminium was thermally annealed (0-16 hours at 500 degrees C) and subsequently anodized to investigate the effects on crystalline structure and anodic alumina characteristics. X-ray diffraction revealed a transformation from polycrystalline to near-single crystalline state, with the (200) plane becoming dominant after 8 hours of annealing. Next, lattice constant analysis showed a reduction in tensile stress from 0.073% to 0.024% above standard values after 12 hours of annealing. Then, field emission scanning electron microscopy and Fast Fourier Transform analysis demonstrated improved pore ordering in anodic alumina films produced from aluminium annealed for 8 hours. Besides that, double-step anodization following electropolishing further enhanced pore uniformity. These findings suggest that controlled thermal annealing of commercial grade aluminium can improve the structural quality and pore ordering of anodic alumina films, potentially expanding their applications in filtration and nanotechnology.
This paper focus on the application of the conjugate gradient algorithm in solving mean-variance portfolio optimization. The characteristics of the resulting optimal portfolio in both bullish and bearish market conditions were evaluated. Effective portfolio optimization is crucial in today's dynamic financial landscape, and the conjugate gradient method emerges as an efficient algorithm for tackling this problem. This paper employs a rolling window approach, utilizing one year of training data followed by one-quarter of testing. Within each window, stationary and normal daily return series are produced, portfolio selection based on correlation matrices and Sharpe ratios is performed, and the mean-variance optimization by the conjugate gradient algorithm is applied to obtain the optimal asset allocation. The study focuses on the S&P 500 index and its constituent stocks from May 1970 to October 2022, leveraging technical analysis without incorporating fundamental factors. The main findings reveal that the mean-variance portfolio is a risk-averse strategy that excels in protecting bearish market conditions but consistently underperforms in bullish environments.
Industrial Platinum Resistance Thermometers (IPRTs) are often made shorter depending on specific application requirements. When using shorter IPRTs, careful calibration is essential to ensure an optimal balance between practicality and measurement accuracy. Prior research emphasizes the effects of heat conduction errors in resistance thermometers at low immersion depths and the usage of metal bushings to improve precision. The calibration of an IPRT is carried out through the comparison method with a Standard Platinum Resistance Thermometer (SPRT), where the probes of both thermometers are immersed directly in a fluid bath. However, it is crucial that both the unit under test and the reference standard are immersed in the same depth in the fluid to prevent significant errors. This study delves into the advantages of employing a glass protective tube and metal bushings to address the limitations of calibrating short-immersion IPRTs. Several calibration techniques were tested, including immersion of the SPRT and IPRTs at the same depth in empty glass tubes, in glass tubes filled with distilled water, and in glass tubes filled with distilled water along with various bushing materials. The final procedure involved changing the bushing material between copper, aluminum, brass, and stainless steel. Results show that copper, brass, and stainless steel bushings enhance accuracy and repeatability at 20 degrees C and 40 degrees C. At 60 degrees C and 80 degrees C, glass tubes with distilled water provide better accuracy but slightly reduced precision compared to metal bushings.
Research on Deep-ultraviolet light-emitting diode (DUV-LED) has become prominent recently due to the demand for purifying and disinfecting the COVID-19 virus in the 2021 pandemic. Unfortunately, the performance of the DUV-LED has been hindered by the Quantum Confined Stark Effect (QCSE) which reduces the recombination of electrons and holes in the quantum wells, thus deteriorating the luminescence intensity. In this research, two epi-structures with different types of quantum wells grading have been investigated and compared with the conventional quantum wells. The analysis covers several important optoelectronics properties such as the band diagram, carrier concentration, electric field, wavefunction of the carrier and luminescence spectrum. It is found that one of the graded quantum wells provides 31% enhancements for luminescence intensity relative to the conventional quantum well and the emission wavelength shifted around 1 nm only.
Calixarenes as the macrocyclic structures have been frequently explored and utilised in a variety of industries. The concept of using calixarenes in drug delivery systems is relatively new, despite calixarenes and their numerous applications have been the subject of countless investigations. In order to build a PABA nanosensor, it is worthwhile to investigate the host-guest interaction between calix[4]arene (C4) and calix[6]arene (C6) with para-aminobenzoic acid (PABA). Using field emission scanning electron microscopy (FESEM), the morphology of ultrathin pure calixarenes and their complexes with PABA were investigated in this study. Moreover, Quantum ESPRESSO was used to conduct the density functional theory (DFT) calculations. Calculations were performed on the band gap and binding energy of C4, C6, PABA, and the new complexes C4-PABA and C6-PABA. In the construction of complexes, several interaction distances were utilised. The morphologies showed the formation of calixarene-PABA complexes. Our findings indicated a narrowing of the band gap for both complexes. In addition, the computed negative binding energy demonstrated the complexes' promising stability at the optimum host-guest ratio of 1:1. These findings denoted the superior detecting ability of calixarenes towards PABA, which might be utilised in future PABA drug sensor applications.
Board games are an effective method in educating the community, especially students, to understand various fields of knowledge. Astronomy, for example, is a discipline that requires knowledge of celestial objects' movements, making it a highly technical and challenging subject. This field demands theoretical understanding and practical experience. The Introduction to Astronomy and Astronomy Management courses in Malaysia are two elective courses offered by the Shariah Studies Center at the Faculty of Contemporary Islamic Studies (FKI), Universiti Sultan Zainal Abidin (UniSZA). Due to the difficulty in studying these two subjects, this study focuses on a hybrid learning technique using board games with the implementation of augmented reality (AR) technology to facilitate students' understanding of Introduction to Astronomy and Astronomy Management in Malaysia. A board game named 'Kembara Alam Hartawan Falak' (AL-KAHF) with AR technology implementation has been developed. The methodology used is both qualitative and quantitative. Qualitatively, a library research method involving documentation of relevant references and unstructured interviews with academicians knowledgeable in Astronomy and AR technology is employed. Meanwhile, quantitatively, a survey method will be distributed to students taking the Introduction to Astronomy and Astronomy Management courses in Malaysia. This aims to assess the readiness and effectiveness of the game with technology in enhancing students' understanding. This study has resulted in the creation of a board game integrated with AR technology for the first time in the field of Islamic studies, particularly in Astronomy. The development of this board game with AR technology is found to be highly relevant for learning and teaching Astronomy. Consequently, it will benefit Malaysia, particularly students of these subjects, as well as academicians and the general public interested in Astronomy.
We conducted Xray analysis on IRAS F03217+4022 and IRAS 13120-5453, two galaxies classified as non AGN previously, but are identified by us as [NeV] lambda 14.32 mu m emitting galaxies. Given the high ionization energy required to produce [NeV] emission, it is an unambiguous indicator for AGN activity. Spectra analysis shows that photon index values for the galaxies are 1.25(-1.49)(+3.53) and 1.45(-0.36)(+0.50) respectively, consistent with typical values of AGNs. Column densities measured shows N-H <= 10(22) cm(-2), suggesting unobscured AGN. Observed luminosities obtained are < 10(42) erg s(-1), lower than the typical values. Comparison of the X-ray to mid-infrared luminosities showcases that the X-rays are suppressed indicating heavily obscured AGNs, suggesting that the column density measured may be significantly underestimated. These results underscore the advantageous of [NeV] as a diagnostic tool and emphasize the need for deeper X-ray observations to confirm the presence of AGN in the future
This paper presents an initial investigation into the quantum reflection of Bose-Einstein Condensate (BEC) from a surface, focusing on the incident angle's role in mitigating saturation effects and enhancing reflection probability at low incident velocities. The research utilizes theoretical modeling of BEC dynamics, implementing the Gross-Pitaevskii equation to simulate the BEC's response to abrupt changes in potential. By adjusting the incident angle, our analysis reveals that it is possible to significantly reduce the saturation effect and improve the quantum reflection probability at low incident velocities. These findings provide new insights into the peculiar behavior of BEC during quantum reflection from a Silicon surface.
Solid electrolyte is a vital component within a battery system that functions as a separator for the migration of ions between electrodes. NASICON-like Na3Zr2(SiO4)(2)PO4 (NZSP) ceramics have garnered attention to be studied as electrolytes in the all-solid-state sodium-ion batteries mainly due to their high ionic conductivity. In this work, Na3Zr2(SiO4)(2)PO4 was chosen as a novel phosphate source to synthesize NZSP via the solid-state reaction method. Excess of sodium (Na) and phosphorus (P) are also added to compensate the loss of volatile elements at elevated temperatures. The effect of lanthanum (La) doping was investigated by fabricating a series of Na3+xLaxZr2-x(SiO4)(2)PO4 (0 <= x <= 0.15) samples. The X-ray diffraction results show that NZSP was formed with monoclinic NASICON-phase with space group C 2/ c . Formation of secondary phases such as Na6La(PO4)(3 ) and Na3La(PO4)(2) in the La-doped samples indicates that La3+ ions tend to form phosphate impurities rather than occupying the Zr(4+ )site in NZSP. Maximum total ionic conductivity value of 7.63 x 10(-4)S cm(-1) was obtained at room temperature for the Na 3.15 La (0.15) Zr (1.85) (SiO 4 ) (2) PO 4 (0.15La-NZSP) sample. It shows that the presence of phosphate impurities and increased of Na in the lattice improves the ionic conductivity by enhancing the mobility of the conducting Na+ + ions. These findings will provide a better understanding on the fabrication of high conductivity solid electrolyte which could lead to many potential benefits such as improvements in a battery operational performance.
Here we report on the impact of low annealing temperatures on the electrical properties of pn junction based on zinc oxide (ZnO as an n-type semiconductor) and p-type silicon (p-Si). Initially, ZnO was deposited over p-Si substrates through a sputtering process. Subsequently, the samples were post annealed at low temperatures in the range of 100 degrees C to 300 degrees C. Then, the samples were metalized for the contacts. The devices were characterised for their crystal structures and morphologies through X-ray diffractometer and field-effect scanning electron microscopy. Further, the current-voltage characteristics were measured as a function of annealing temperatures. The results of fabricated pn junction reveal a high rectification ratio of the prepared junctions. In addition, it was found that the annealing temperatures play a significant role in the junction parameters (namely, the barrier height and the ideality factor). The barrier height values of the prepared junction were reduced from 0.877 to 0.752 eV. The ideality factor values followed the same trend and decreased from 6.65 to 3.54. The findings of this study demonstrated that increasing the annealing temperature enhanced the electrical properties of the ZnO-based diode.
