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The input electrical impedance behaves as a capacitive when a piezoelectric transducer is excited near its resonance frequency. In order to increase the energy transmission efficiency, a series or parallel inductor should be used to compensate the capacitive impedance of the piezoelectric transducer. In this paper, the effect of the series matching inductor on the electromechanical characteristics of the piezoelectric transducer is analyzed. The dependency of the resonance/anti-resonance frequency, the effective electromechanical coupling coefficient, the electrical quality factor and the electro-acoustical efficiency on the matching inductor is obtained. It is shown that apart from compensating the capacitive impedance of the piezoelectric transducer, the series matching inductor can also change the electromechanical characteristics of the piezoelectric transducer. When series matching inductor is increased, the resonance frequency is decreased and the anti-resonance unchanged; the effective electromechanical coupling coefficient is increased. For the electrical quality factor and the electroacoustic efficiency, the dependency on the matching inductor is different when the transducer is operated at the resonance and the anti-resonance frequency. The electromechanical characteristics of the piezoelectric transducer with series matching inductor are measured. It is shown that the theoretically predicted relationship between the electromechanical characteristics and the series matching inductor is in good agreement with the experimental results.

We have provided the first estimate of scattering and intrinsic attenuation for the Gargano Promontory (Southern Italy) analyzing 190 local earthquakes with ML ranging from 1.0 to 2.8. To separate the intrinsic Qi and scattering Qs quality factors with the Wennerberg approach (1993), we have measured the direct S waves and coda quality factors (Qβ, Qc) in the same volume of crust. Qβ parameter is derived with the coda normalization method (Aki 1980) and Qc factor is derived with the coda envelope decay method (Sato 1977). We selected the coda envelope by performing an automatic picking procedure from Tstart=1.5TS up to 30 s after origin time (lapse time TL). All the obtained quality factors clearly increase with frequency. The Qc values correspond to those recently obtained for the area. The estimated Qi are comparable to the Qc at all frequencies and range between 100 and 1000. The Qs parameter shows higher values than Qi, except for 8 Hz, where the two estimates are closer. This implies a predominance of intrinsic attenuation over the scattering attenuation. Furthermore, the similarity between Qi and Qc allows us to interpret the high Qc anomaly previously found in the northern Gargano Promontory up to a depth of 24 km, as a volume of crust characterized by very low seismic dumping produced by conversion of seismic energy into heat. Moreover, most of the earthquake foci fall in high Qi areas, indicating lower level of anelastic dumping and a brittle behavior of rocks.

High sensitivity and high quality‐factor are crucial for achieving outstanding sensing performance in photonic biosensors. However, strong optical field confinement and high light–biomolecule interactions on photonic surfaces are usually contradictory and challenging to satisfy simultaneously. Here, a distinctive configuration for addressing this issue is reported: embedding a nanophotonic metasurface inside a micro vertical cavity as a meta‐channel (metacavity) biosensor. The analyte solution serves as the cavity medium, thereby maximizing the light–analyte interaction. Simulation validation is conducted to optimize the metacavity with high structural robustness and remarkable optical and sensing properties. Large‐scale low‐cost metacavity biosensors are realized by combining anodic aluminum oxide template technique and wafer bonding. Experimentally, the metacavity biosensor demonstrates a notable quality‐factor (maximum 4140) and high bulk refractometric sensitivity (450 nm RIU−1), resulting in an unprecedented figure‐of‐merit (1670 RIU−1). Moreover, the metacavity biosensor achieves high surface sensitivity, together with a detection‐limit of 119 viral copies mL−1 for label‐free severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pseudovirus sensing, revealing remarkable performance in both bulk and surface sensing. To address the challenge of balancing strong optical field confinement with the associated decrease in sensitivity in high‐quality‐factor photonic resonator sensors, a distinct analyte medium metasurface‐enhanced microcavity (metacavity) biosensor is introduced. Owing to its ingenious design, the metacavity maintains an ultra‐high Q‐factor with a notable sensitivity, leading to an exceptional figure‐of‐merit. The overall performance surpasses that of conventional resonator sensors.

Criteria for establishing the quality of action research is of increasing interest to researchers and practitioners however, it is not known how well these criteria are used. This review addresses this issue by appraising extant measures that assess quality in action research. Taking Coghlan and Shani’s (2014, 2018) four quality factors: context, quality of relationships, quality of the action process and outcomes, this scoping review examines if and how these factors have featured as quality criteria. While all studies included in this review reported on the four quality factors, no study reported in any detail on how any of the factors were integrated with one another. Findings therefore highlight a significant gap in the monitoring and reporting on the quality of action research studies. Addressing these gaps will support the development of future action research aimed at mitigating the lack of quality associated with action research approaches.

In order to quantitatively describe the energy dissipation law of jointed rock mass, we obtained the jointed cores in laboratory conditions using marble from the roof and floor of Jinchanghe Lead–zinc mine in Baoshan. The dissipative degree of stress wave in marble jointed rock mass is measured by introducing quality factor Qs parameter. Based on the experimental principle of Split Hopkinson Pressure rod loading device (SHPB), we proposed a three-wave energy method of incident wave, reflected wave and projected wave for calculating jointed rock samples’ quality factor Qs based on stress wave energy. Using the SHPB test system for multiple specimens taken from the same piece of rock mass shock compression experiment, the three groups of specimens under different loading conditions gained incident wave and reflected wave and transmission wave experimental data, using the method of stress wave energy to deal with stress wave data, and calculate the joint sample maximum storage energy, dissipation energy and Qs quality factors. The results show that: ① The non-destructive breaking time–history strain of Dali rock mass under impact load is obtained by SHPB dynamic test system; combined with the deformation energy and dissipation energy calculation principle of quality factor, six groups of Qs experimental values are obtained. Although the Qs experimental values are discrete, the overall deviation is small with an average of 43.07. ② AUTODYN-Code was used to simulate the damage and fracture characteristics of rock mass with different quality factors under explosive dynamic load. The results showed that the radius of rock mass compression shear damage area gradually increased with the increase in porosity, but it was not obvious.

From a public health perspective, it is necessary to improve indoor air quality (IAQ) in schools. This study aims to assess the state of perceived IAQ in Slovenian school classrooms and its association with the selected IAQ factors to improve the understanding of perceived IAQ for designing public health interventions aimed to improve IAQ in schools. A national cross-sectional study was performed in all 454 Slovenian primary schools in the school year 2019/2020. The questionnaires were filled out by the 3rd-grade teachers with the support of the caretakers. Teachers rated the IAQ in the classroom as the worst in winter. We found that the teachers’ perceived IAQ in the classroom is statistically significantly associated with the micro location of the school and some of the IAQ factors. Poor IAQ is associated with reduced manual airing of classrooms due to the thermal comfort of the occupants. Interventions should be aimed at improving occupants’ adaptive behaviors to increase the frequency of natural ventilation in classrooms.

We demonstrate the design and simulation of a long range four-channel wavelength division multiplexing-passive optical network (WDM-PON) operating at 40 Gb/s (4 × 10 Gb/s) in downstream transmission for undersea wireless optical communication. The proposed model consists of two separate subsections between the optical transmitter and receiver. The first subsection consists of the central office and 50 km long feeder fiber for transmitting the optical signal from a distant base station to the 1 × 4 optical demultiplexer located at the sea shore. The second subsection comprises 500 m distributed fiber from the 1 × 4 optical demultiplexer to the terminal point placed at the bottom of the sea and 15–20 m optical wireless channel inside sea water. Simulation results confirmed successful transmission of optical signals from the 50 km distant optical transmitter to the optical receiver located maximum 15 m inside the sea water with a signal-to-noise ratio of ∼20.96 dB, bit error rate of ∼1.55 × 10 , and quality factor of ∼5.584. The eye diagram at the receiving end also exemplifies quality downstream data transmission at a rate of 10 Gb/s per channel. In addition, we compare the simulation results of the four-channel 40 Gb/s WDM-PON system with a four-channel WDM-PON system operating at 4 Gb/s (4 × 1 Gb/s). Simulation results confirm maximum reach of 17.5 m inside sea water at a cost of significant reduction in data rate. Furthermore, we analyze the system availability of the proposed WDM-PONs and find convincing results for high-speed secured data transmission under water.

The volume of health-related user-created content, especially hospital-related questions and answers in online health communities, has rapidly increased. Patients and caregivers participate in online community activities to share their experiences, exchange information, and ask about recommended or discredited hospitals. However, there is little research on how to identify hospital service quality automatically from the online communities. In the past, in-depth analysis of hospitals has used random sampling surveys. However, such surveys are becoming impractical owing to the rapidly increasing volume of online data and the diverse analysis requirements of related stakeholders. As a solution for utilizing large-scale health-related information, we propose a novel approach to identify hospital service quality factors and overtime trends automatically from online health communities, especially hospital-related questions and answers. We defined social media-based key quality factors for hospitals. In addition, we developed text mining techniques to detect such factors that frequently occur in online health communities. After detecting these factors that represent qualitative aspects of hospitals, we applied a sentiment analysis to recognize the types of recommendations in messages posted within online health communities. Korea's two biggest online portals were used to test the effectiveness of detection of social media-based key quality factors for hospitals. To evaluate the proposed text mining techniques, we performed manual evaluations on the extraction and classification results, such as hospital name, service quality factors, and recommendation types using a random sample of messages (ie, 5.44% (9450/173,748) of the total messages). Service quality factor detection and hospital name extraction achieved average F1 scores of 91% and 78%, respectively. In terms of recommendation classification, performance (ie, precision) is 78% on average. Extraction and classification performance still has room for improvement, but the extraction results are applicable to more detailed analysis. Further analysis of the extracted information reveals that there are differences in the details of social media-based key quality factors for hospitals according to the regions in Korea, and the patterns of change seem to accurately reflect social events (eg, influenza epidemics). These findings could be used to provide timely information to caregivers, hospital officials, and medical officials for health care policies.

The quality factor (Q) is formally linked to the stochastic (e.g., carcinogenic) risk of diverse ionizing radiations at low doses and/or low dose rates. Q can be a function of the non-stochastic physical quantity Linear Energy Transfer (LET) or the microdosimetric parameter lineal energy (y). These two physical quantities can be calculated either by Monte Carlo (MC) track-structure simulations or by analytic models. In this work, various generalized analytical models were utilized and combined to determine the proton lineal energy spectra in liquid water spheres of various sizes (i.e., 10–3000 nm diameter) over the proton energy range of 1–250 MeV. The calculated spectra were subsequently used within the Theory of Dual Radiation Action (TDRA) and the ICRU Report 40 microdosimetric methodologies to determine the variation of Q¯ with proton energy. The results revealed that the LET-based Q values underestimated the microdosimetric-based Q¯ values for protons with energy below ~100 MeV. At energies relevant to the Bragg peak region (<20–30 MeV), the differences were larger than 20–50%, while reaching 200–500% at ~5 MeV. It was further shown that the microdosimetric-based Q¯ values for protons below ~100 MeV were sensitive to the sphere size. Finally, condensed-phase effects had a very small (<5%) influence on the calculated microdosimetric-based Q¯ over the proton energy range considered here.

Poor indoor air quality (IAQ) in schools is associated with impacts on pupils’ health and learning performance. We aimed to identify the factors that affect IAQ in primary schools. The following objectives were set: (a) to develop a questionnaire to assess the prevalence of factors in primary schools, (b) to conduct content validity of the questionnaire, and (c) to assess the prevalence of factors that affect the IAQ in Slovenian primary schools. Based on the systematic literature review, we developed a new questionnaire to identify factors that affect the IAQ in primary schools and conducted its validation. The questionnaires were sent to all 454 Slovenian primary schools; the response rate was 78.19%. The results show that the most important outdoor factors were the school’s micro location and the distance from potential sources of pollution, particularly traffic. Among the indoor factors, we did not detect a pronounced dominating factor. Our study shows that the spatial location of schools is key to addressing the problem of IAQ in schools.