Quality Factor Research Articles

Angled fiber-coupled mgf[formula omitted] microcavities for nonlinear optics in 1.5 and [formula omitted] bands

A versatile angled fiber coupling platform for magnesium fluoride whispering gallery mode resonators is used to investigate nonlinear frequency conversion across 1.5 and 2 μm bands. We characterize MgF2 microcavities of varying sizes (4.3 mm, 1.9 mm, and 0.73 mm in diameter), achieving quality factors up to 2×109 at 1.55μm and 5×108 at 1.94μm. In the telecom regime, we observe rich nonlinear phenomena including Kerr comb generation, Brillouin lasing, and Raman lasing. Extending to the 2 μm band, we demonstrate four-wave mixing in a sub-millimeter cavity, highlighting the platform’s potential for the 2 μm band mid-infrared nonlinear optics.

Achieving low thermal conductivity and high quality factor in sextuple-doped TiS2

Transition-metal dichalcogenide TiS2 stands out as a sustainable candidate for room- and medium-temperature thermoelectric materials due to its affordability, non-toxicity, eco-friendly nature and use of non-critical elements. However, its light element compositional nature results in a large thermal conductivity, which is the main limitation of the thermoelectric performance of TiS2. Here, we report a multi-element doping strategy by incorporating equivalent (Se, Zr) elements and introducing higher-valence (Nb, Ta) and lower-valence (Y, La) elements in pairs to minimize its lattice thermal conductivity, κlat. The findings indicate a nearly 50% decrease in κlat across the entire temperature range, attributed to the presence of strong point-defect scattering after multi-element doping. Additionally, we observed a reduced dependency of κlat on temperature in multi-element doped TiS2, as point defects can effectively scatter phonons at room temperature. As a result, the multi-element doped TiS2 attained its highest ZT value of approximately 0.4 at 625 K. Incorporating higher-valence and lower-valence elements in pairs proves to be an effective method for decreasing lattice thermal conductivity without compromising too much of its large Seebeck coefficient.

Design of IoT-based monitoring system for temperature and dissolved oxygen levels in catfish aquaculture pond water

<span>One of the fish in Indonesian waters that has been successfully bred and cultivated is the catfish (Pangasius sp.). In catfish farming, there are several water quality factors that need to be considered, such as temperature and dissolved oxygen levels. Based on the existing description, it is very important to pay attention to the water quality of aquaculture ponds, especially temperature and dissolved oxygen levels for fish survival. This study aims to create an internet of things (IoT) based monitoring system for temperature and dissolved oxygen levels in catfish aquaculture pond water based on NodeMCU ESP8266. Monitoring system is using SEN0237 gravity analog dissolved oxygen sensor, DS18B20 sensor module, NodeMCU ESP8266, 20×4-character liquid-crystal display (LCD), micro secure digital (SD) card module, internet modem. Data from measurements of temperature and dissolved oxygen levels are stored online in the Adafruit.io database in the .csv format and on a micro secure digital (SD) card in the device in the .txt format. The lowest value of dissolved oxygen levels and temperature are 3.4 mg/L or 3.4 ppm and a temperature of 27.9 °C, respectively. Meanwhile, the highest value of dissolved oxygen levels and temperature are 4.6 mg/L or 4.6 ppm and temperature of 30.9 °C, respectively.</span>

A closed-loop sustainable method for the fabrication of electrospun nanofiber using food waste for filtration of particulate matters (PMs) and volatile organic matter (VOCs) from air

Indoor air pollution significantly impacts human health and the environment. Humans suffer the greatest health burden due to inefficient combustion technologies and polluted fuels. Therefore, air filtration is essential for a healthy and prosperous household. This study aims to develop a sustainable approach for the fabrication of biodegradable electrospun nanofibers (ENs) as air filters from food waste materials and offer a closed-loop circular solution and potential replacement for non-biodegradable HEPA air filters. We have tested banana peel extract (BPE), eggshell membrane, chitosan, and starch blended with polyvinyl alcohol (PVA) for fabricating ENs. Among the nanofibers investigated for air filtration application, BPE/PVA nanofiber shows the best performance in terms of maximum particulate matter (PM) removal efficiency and minimum pressure drop while incorporating > 50 % of the food waste into the electrospinning solution. Adding BPE into a 10 % PVA solution leads to a reduction in the hydrophilic behavior of the BPE/PVA nanofiber as compared to neat 10 % PVA ENs. The BPE/PVA nanofiber shows minimum pressure drop (156–160 Pa) and highest quality factor (Qf) in comparison with other waste-derived nanofibers with > 98 % filtration efficiency of PM2.5. Further, BPE/PVA nanofiber shows the highest adsorption of xylene vapor among other food waste derived nanofibers studied. Based on the above results, it can be concluded that BPE based nanofiber shows the best performance as air filter media among all other food waste-based ENs. The study demonstrates a successful regeneration and reuse of the BPE/PVA filter up to 3 cycles. The leftover material from banana peels after BPE extraction was utilized as a soil ameliorant. It showed 55 % soil water retention (SWR) capacity, making it possible to apply in arid regions or crops with high water requirements.

Characterization of temperature-dependent full-matrix constants of [001]c-poled Mn-doped 28PIN-43PMN-29PT single crystals using one sample

[001]c-poled Mn-doped xPb(In1/2Nb1/2)O3–(1–x–y)Pb(Mg1/3Nb2/3)O3–yPbTiO3 (PIN–PMN–PT:Mn) single crystals (SCs) in the rhombohedral phase possess not only excellent piezoelectric properties but also a high mechanical quality factor, which make them suitable for fabricating high-performance piezoelectric devices. Characterizing the temperature dependence (TD) of full-matrix constants is indispensable for their use in device design. However, there is a significant lack of relevant data. In this study, the TD of the clamped dielectric properties of [001]c-poled 28PIN-43PMN-29PT:Mn SCs was characterized using a dielectric temperature spectroscopy measurement system from 0 to 60 °C. Their elastic and piezoelectric constants were measured using resonant ultrasound spectroscopy in the same temperature range. With an increase in the temperature, all the elastic stiffness constants decreased, whereas all the clamped dielectric constants and the absolute values of all the piezoelectric stress constants increased. The characterization process required only a single sample, which ensured the consistency of the results. Furthermore, the electrical impedance spectra of the sample at 30 and 50 °C were measured and compared with those simulated using the finite-element method with the characterization results. The close agreement between them confirmed the reliability of the characterization results.

915 nm pumping kilowatt fiber oscillator with high optical-to-optical efficiency

We demonstrate an all-fiber oscillator with high optical-to-optical efficiency using laser diodes working at 915nm as the pump sources to reduce the demand for thermal management. When the output power of the bidirectional pumped oscillator is 1.16kW, the optical-to-optical efficiency is as high as 75.4%. In this working state, the output characteristics of the oscillator are observed. The Raman suppression ratio is 41.23dB and the beam quality factor Mx2 = 1.14, My2 = 1.29. Analyzing the time trajectory of the highest power output, there are no significant characteristic peaks in the time domain signal and the frequency domain signal, which indicates that the oscillator has good stability.Improving the output characteristics of the 915nm pumping lasers has a positive significance for the application of non-strict ambient temperature control.

Band edge modulation for high-performance LL-SAW resonators on LiNbO3/SiC by introducing an ultra-thin intermediate oxide layer

With the exploding demand of rapid information transmission, high-frequency acoustic filtering devices are becoming an immediate need. Longitudinal leaky surface acoustic wave (LL-SAW) devices with unique advantages can be a promising platform. In this paper, we introduce a 100 nm intermediate oxide layer into the X-cut lithium niobate on silicon carbide (LiNbO3/SiC) to improve the in-band performance of LL-SAW resonators. First, the dispersion curves of the structures are analyzed by finite element method. In this part, we successfully interpret the intrinsic low quality factor (Q) of LL-SAW on LiNbO3/SiC in general design, and predict the enhancement of Q by introducing an intermediate oxide layer without degradation on spurious response. Then, one port resonators considered in the simulation are fabricated and measured. As a result, enhancements in Bode Q among the whole passband are confirmed. Compared with devices state of art, resonators with leading performances are demonstrated. The fabricated resonators have peak-valley admittance ratio of 63.87 dB, Bode Q of ∼300 at fr and ∼530 at far, keff2of 15.66 % and phase velocity of 6187.3 m/s. Additionally, the resonant frequency of SH1 mode shifts to higher frequency. This work enables the design of next generation high frequency mobile communication filters.

Energy harvesting properties for potassium-sodium niobate piezoceramics through synergistic effect of phase structure and texturing engineering

In order to address the energy dilemma and meet environmental protection requirements, it is an urgent need to develop lead-free piezoelectric energy harvesters (PEHs). However, the low output power density has seriously hindered the application of lead-free piezoceramics as high efficiency energy harvesters. To solve above question, the combination of phase structure regulation and texturing technique in the K0.5Na0.5NbO3-xBi0.5Na0.5ZrO3-0.5%wtBiFeO3 (KNN-xBNZ) ceramics was adopted in this work. Because of both the Rhombohedral-Orthorhombic-Tetragonal (R-O-T) multiphases coexistence and texturing engineering, an ultrahigh piezoelectric activity quality factor d33×g33 ∼ 18324 ×10-15 m2·N-1 was achieved in the textured KNN-0.05BNZ (T-KNN-0.05BNZ) ceramics, which is about third times higher than that of random KNN-0.05BNZ (R-KNN-0.05BNZ) (d33×g33 ∼ 6672 ×10-15 m2·N-1) ones. A high output power of ∼ 0.32 mW was also obtained in the T-KNN-0.05BNZ ceramics by cantilever beam-based energy harvester devices under the resonance frequency of 75 Hz and matched RL of 1.2 MΩ, suggesting that the T-KNN-0.05BNZ ceramics have a great potential for application in the PEHs devices. This result also reveals that the combination of phase structure regulation and texturing technique is an effective way to achieved a high energy harvesting performances.

A Study on the Impact of Quality and HCI Factors of a Deep Learning-Based Makeup Recommendation System on Acceptance Intention: Focusing on the Mediating Effects of Users’ Perceived Trust and Immersion

This study analyzed the impact of system quality and HCI factors on user acceptance intention, mediated by perceived trust and immersion, in the context of a deep learning-based makeup recommendation system. The results indicate that system quality and HCI factors significantly influence user acceptance intention through perceived trust and immersion. This underscores the importance of system quality and HCI factors for the successful application of makeup recommendation systems. In particular, factors such as diversity, accuracy, anthropomorphism, and realism enhance user trust and immersion, leading to higher acceptance intention. However, it was found that certain factors, such as personalization, do not significantly influence acceptance intention through immersion. This suggests that the impact of specific factors should be considered in the design of recommendation systems. The study is limited by its focus on a specific age group and gender in the survey, which may restrict the generalization of the results. Additionally, there is a lack of research on users with different cultural backgrounds, necessitating an understanding of the global market applicability. Future research should extend to users with diverse demographic characteristics to derive universal design principles for makeup recommendation systems. Furthermore, the impact of factors such as personalization on user experience should be explored in depth to enhance user-centered, customized beauty services. This research provides a theoretical and practical foundation for the effective design and implementation of makeup recommendation systems and is expected to contribute to the digital transformation of the beauty industry.

Silicon rich nitride: a platform for controllable structural colors

Abstract High refractive index dielectric materials like silicon rich nitride (SRN) are critical for constructing advanced dielectric metasurfaces but are limited by transparency and complementary metal oxide semiconductor (CMOS) process compatibility. SRN’s refractive index can be adjusted by varying the silicon to nitride ratio, although this increases absorption, particularly in the blue spectrum. Dielectric metasurfaces, which utilize the material’s high dielectric constant and nano-resonator geometry, experience loss amplification due to resonance, affecting light reflection, light transmission, and quality factor. This study explores the impact of varying the silicon ratio on structural color applications in metasurfaces, using metrics such as gamut coverage, saturation, and reflection amplitude. We found that a higher SRN ratio enhances these metrics, making it ideal for producing vivid structural colors. Our results show that SRN can produce a color spectrum covering up to 166 % of the sRGB space and a resolution of 38,000 dots per inch. Fabricated samples vividly displayed a parrot, a flower, and a rainbow, illustrating SRN’s potential for high-resolution applications. We also show that SRN can provide a better CIE diagram coverage than other popular metasurfaces materials. These findings highlight the advantages of SRN for photonic devices, suggesting pathways for further material and application development.

A microsystem for in vivo wireless monitoring of plastic biliary stents using magnetoelastic sensors.

With an interest in monitoring the patency of stents that are used to treat strictures in the bile duct, this paper reports the investigation of a wireless sensing system to interrogate a microsensor integrated into the stent. The microsensor is comprised of a 28-μm-thick magnetoelastic foil with 8.25-mm length and 1-mm width. Magnetic biasing is provided by permanent magnets attached to the foil. These elements are incorporated into a customized 3D polymeric package. The system electromagnetically excites the magnetoelastic resonant sensor and measures the resulting signal. Through shifts in resonant frequency and quality factor, the sensor is intended to provide an early indication of sludge accumulation in the stent. This work focuses on challenges associated with sensor miniaturization and placement, wireless range, drive signal feedthrough, and clinical use. A swine specimen in vivo experiment is described. Following endoscopic implantation of the sensor enabled plastic stent into the bile duct, at a range of approximately 17 cm, the signal-to-noise ratio of ~106 was observed with an interrogation time of 336 s. These are the first reported signals from a passive wireless magnetoelastic sensor implanted in a live animal.

The Implementation of Service Quality, Perception of Price, Location Towards Purchasing Decisions (Case Study of Coffee Shops in North Bekasi)

The purpose of this study is to ascertain how price perception, location, and service quality affect customers' decisions to buy from Identiq Coffee Shop. This kind of study is quantitative in nature. This study's population is unknown. Purposive sampling combined with non-probability sampling is a sampling strategy. There were 96 responders in the study's sample. methods for gathering data by sending out surveys with Google Form. Multiple Linear Regression analysis was used in this work to test hypotheses. A number of coffee shops in North Bekasi are the topic of the study. The study's findings show that the factors of location, price perception, and service quality all significantly and concurrently positively affect the purchasing decision variable.

Formation of quasi-bound states in the continuum in a single deformed microcavity

Bound states in the continuum (BICs) hold significant promise in manipulating electromagnetic fields and reducing losses in optical structures, leading to advancements in fundamental research and practical applications. Despite their observation in various optical systems, the behavior of BIC in whispering-gallery-modes (WGMs) optical microcavities, essential components of photonic integrated chips, has yet to be thoroughly explored. In this study, we propose and experimentally identify a robust mechanism for generating quasi-BIC in a single deformed microcavity. By introducing boundary deformations, we construct stable unidirectional radiation channels as leaking continuum shared by different resonant modes and experimentally verify their external strong mode coupling. This results in drastically suppressed leaking loss of one originally long-lived resonance, manifested as more than a threefold enhancement of its quality (Q) factor, while the other short-lived resonance becomes more lossy, demonstrating the formation of Friedrich–Wintgen quasi-BICs as corroborated by the theoretical model and experimental data. This research will provide a practical approach to enhance the Q-factor of optical microcavities, opening up potential applications in the area of deformed microcavities, nonlinear optics, quantum optics, and integrated photonics.

Elastic Wave Scattering off a Single and Double Array of Periodic Defects

The scattering problem of elastic waves impinging on periodic single and double arrays of parallel cylindrical defects is considered for isotropic materials. An analytic expression for the scattering matrix is obtained by means of the Lippmann–Schwinger formalism and analyzed in the long-wavelength approximation. It is proved that, for a specific curve in the space of physical and geometrical parameters, the scattering is dominated by resonances. The shear mode polarized parallel to the cylinders is decoupled from the other two polarization modes due to the translational symmetry along the cylinders. It is found that a relative mass density and relative Lamé coefficients of the scatterers give opposite contributions to the width of resonances in this mode. A relation between the Bloch phase and material parameters is found to obtain a global minimum of the width. The minimal width is shown to vanish in the leading order of the long wavelength limit for the single array. This new effect is not present in similar acoustic and photonic systems. The shear and compression modes in a plane perpendicular to the cylinders are coupled due to the normal traction boundary condition and have different group velocities. For the double array, it is proved that, under certain conditions on physical and geometrical parameters, there exist resonances with the vanishing width, known as Bound States in the Continuum (BSC). Necessary and sufficient conditions for the existence of BSC are found for any number of open diffraction channels. Analytic BSC solutions are obtained. Spectral parameters of BSC are given in terms of the Bloch phase and group velocities of the shear and compression modes.

Tunable enhancement of the cylindrical Luneburg lens focusing ability with the aid of a conformal graphene strip

We consider the plane wave focusing characteristics of the layered cylindrical Luneburg lens equipped with a conformal strip of graphene, in the H-polarization case. The angular width and location of the strip is arbitrary, and its surface impedance is characterized with the aid of the quantum-physics Kubo formalism. We use a mathematically accurate full-wave analytical regularization technique, which is based on the explicit inversion of the problem static part and yields a Fredholm second-kind matrix equation. This guarantees the convergence of the resulting meshless numerical algorithm. We compute the focusing ability of a microsize lens as a function of the frequency in the wide range up to 60 THz. This analysis shows that a graphene strip, placed into the focal area of the Luneburg lens, enhances its focusing ability at the resonance frequency of the strip plasmon mode proportionally to the quality factor. This frequency is defined by the strip width and is tunable with the aid of graphene’s chemical potential.

Evaluating the general V(λ), mismatch spectral quality factor index ƒ₁ and the uncertainty of photometers

The general term photometry refers to the measurement of light and its perceived brightness; it can be applied to various purposes, including lighting design, display calibration, and the setting of safety standards. A device used for measuring light is called a light meter or photometer. Ideally, such devices should have a spectral responsivity-that is, they should respond to light in a way which mimics the human eye's sensitivity to different wavelengths. The sensitivity of the human eye is described by the Commission Internationale de l'Éclairage, CIE, luminous efficiency function, V(λ), a plot of the sensitivity of the eye versus wavelength over the visible region, from violet, approximately 380 nm, through red, approximately 780 nm. In practical applications, it is usually preferable to detect light with silicon or selenium photodetectors and measure the electrical current generated. These photodetectors are sensitive to a wide range of wavelengths, including those outside of the visible spectrum: ultraviolet (UV) and infrared (IR). However, due to its nature, the spectral responsivity of silicon and selenium photodetectors is also different from that of the human eye. For example, silicon photodetectors are much more sensitive to infrared radiation, which is imperceptible to human vision. This in turn leads to erroneous light measurements when using the direct raw response of the detector. The spectral quality factor and , indicating the mismatch between the spectral responsivity and the CIE luminous efficiency function V(λ), is the most crucial characteristic of photometers. The general mismatch index , denoted as V(λ), delineates the disparity between a photometer's relative spectral responsivity and the spectral luminous efficiency function for photopic vision, V(λ). It's highly probable that photometers will adopt white light-emitting diode (LED) sources as calibration references going forward. This transition may necessitate refining the general V(λ) mismatch index's definition, possibly through alternative normalization methods for or by introducing a different assessment function for evaluating mismatches . In this research, spectral quality factor for the photometer NIS-2 has been determined with value 3.8%. This percentage value is classified the photometer NIS-2 as medium quality. The uncertainty was determined through a calculation performed using my Microsoft Excel program, and the final value obtained is 0.010.

The Influence of External Audit Quality on Discretionary Accruals and Real Earnings Management Practices: An Analysis of Malaysian Firms

This paper aims to analyse the mitigating effects of external audit quality (EAQ) factors on earnings management (EM) practices. Data were collected from firms listed on Bursa Malaysia’s main market, covering the years 2011 through 2022. Panel regression was employed to analyse the data. The findings of this study confirmed a significant negative association between audit reputation, audit quality, audit opinions, and EM of listed firms in Malaysia. Audit fees and audit tenure were found to be not significant in relation to EM. The study included five control variables in the analysis, and only economic value added (EVA) was found to be significant. The findings suggest that a number of audit quality factors are indicative of EM among listed firms. The authors extend, as well as contribute to, the growing literature on the EAQ, and therefore, wider corporate governance literature. Thus, it provides originality by presenting empirical evidence and outcomes to fully understand how discretionary accrual and real EM affect EAQ in the Malaysian context. Therefore, stakeholders should place higher concern on the selection of an external auditor, and investors should take into account the external audit factors when making investment decisions. Measuring the effectiveness of EAQ allows decision-makers to evaluate how effective employed governance measures are in improving shareholders’ perceptions of financial information quality and mitigating EM practices.

Application of active piezoresistive cantilevers in high-eigenmode surface imaging

Abstract One of the most important limitations of the atomic force microscopy (AFM) is scanning speed, whose high values are required for contemporary high-resolution, long-range diagnostic applications. The measurement bandwidth of an AFM depends on several factors, but usually results from the time constant of the oscillating cantilever, which is correlated with its resonance frequency and quality factor. We propose a method to overcome this problem by performing the surface measurements when the cantilever is vibrating in higher eigenmodes. In this paper we demonstrate the application of active piezoresistive cantilevers operating in this mode. The active piezoresistive cantilever comprises a piezoresistive deflection sensor, a deflection actuator and a nanotip. It is a complete micro-electro-mechanical system (MEMS), ensuring the highest reliability of cantilever vibration control and detection. Higher eigenmode operations are usually difficult to implement as they usually result in lower deflection and lower sensitivity of the probe vibration deflection. Here we present an experimental modification of the structure of an active piezoresistive cantilever using focused ion beam (FIB) machining that mitigates both weaknesses. This has enabled the cantilever to scan the surface at a scanning rate of 10 lines/s with a maximum speed of 500 μm/s and a data acquisition rate of 10 kS/s, when the probe is vibrating at 380 kHz in the second eigenmode. We also describe a traceable calibration routine (based on analysis of the response of the piezoresistive detector, the output of the HeNe interferometer and precise control of the deflection actuator), together with the cantilever modification process and the development of the measurement setup. We show measurement results of dedicated calibration samples and silicon carbide crystal lattice references.

Navigating the digital tax landscape: The impact of service quality factors on E-filing adoption among individual taxpayers in Jakarta

Tax administration digitization improves taxpayer experience through e-filing, supported by service quality, trust, and information technology. This study integrates electronic service quality to understand the decision to use E-filing, offering a comprehensive approach with the E-Filling model to create digital records that are easily accessible. This study analyzes the effect of quality factors on the use of E-filing, with mediation from perceived ease of use and perceived usefulness. The study design uses an explanatory with a causal approach to confirm the relationship between variables related to the use of e-filing by taxpayers in Jakarta. Samples were taken from 10,580,475 taxpayers, with 150 respondents based on certain criteria. Primary data were collected through an online survey using a Likert scale. The measurement model was tested for validity and reliability, as well as structural analysis to assess the relationship between variables using path coefficients and bootstrapping analysis for significance. The coefficient of determination (R²) and path analysis were also conducted to measure the impact of mediating variables. The study shows that of the various service quality factors, only responsiveness has a significant effect on the perception of e-filing usefulness with a T-statistic of 3.253 and a P value of 0.001. Meanwhile, the informativeness, reliability, and system availability factors do not show a significant effect on the perception of ease and usefulness, indicating the need for improvement in information delivery and system reliability. High responsiveness is very important in supporting positive perceptions of the usefulness of the e-filing system. Path analysis shows that neither perceived ease of use nor perceived usefulness affect the actual use of e-filing, with R Square only explaining 2.6% of the variation in use. Although the research model shows an adequate fit with an NFI of 0.786, improvements are still needed to increase e-filing adoption. Thus, focusing on improving responsiveness and optimizing other factors is needed to improve user experience. It is necessary to improve the responsiveness of the e-filing system and improve informativeness, reliability, and system availability to improve user perception. Future research is suggested to develop interventions for service factors that are not yet significant and explore other elements that influence e-filing adoption.

Effect of institute and LMS service quality on HEI Brand Equity: an empirical investigation

Purpose The purpose of this paper is to examine the education service quality factors, for online education context, that drive the brand equity of a higher education institute. In the times of emerging online education programmes by otherwise traditional institutes, assessing the service quality of educational institutions and its effect on the institute’s brand represents an extant research gap. Design/methodology/approach This study addresses the gap by empirically measuring higher education institution (HEI) service quality and explores its impact on student engagement, satisfaction and brand equity. This research analyses structured data from 250 students, through partial least squares-based structural equation modelling, to test the proposed hypotheses. Findings Within the overall service quality of an HEI, all components of institutional service quality are found to affect student engagement strongly; however, only some dimensions of learning management system service quality do. Student engagement is found to positively impact student satisfaction which, in turn, strongly affects all elements of HEI brand equity. Originality/value This study adds value to the extant research in higher education service quality by adding a layer of online platform service quality and offers actionable insights for HEI administrators.