Plasmonic metasurfaces of cellulose nanocrystal matrices with quadrants of aligned gold nanorods for photothermal anti-icing.

Cellulose nanocrystals (CNCs) are intriguing as a matrix for plasmonic metasurfaces made of gold nanorods (GNRs) because of their distinctive properties, including renewability, biodegradability, non-toxicity, and low cost. Nevertheless, it is very difficult to precisely regulate the positioning and orientation of CNCs on the substrate in a consistent pattern. In this study, CNCs and GNRs, which exhibit tunable optical and anti-icing capabilities, are employed to manufacture a uniform plasmonic metasurface using a drop-casting technique. Two physical phenomena-(i) spontaneous and rapid self-dewetting and (ii) evaporation-induced self-assembly-are used to accomplish this. Additionally, we improve the CNC-GNR ink composition and determine the crucial coating parameters necessary to balance the two physical mechanisms in order to produce thin films without coffee rings. The final homogeneous CNC-GNR film has consistent annular ring patterns with plasmonic quadrant hues that are properly aligned, which enhances plasmonic photothermal effects. The CNC-GNR multi-array platform offers above-zero temperatures on a substrate that is subcooled below the freezing point. The current study presents a physicochemical approach for functional nanomaterial-based CNC control.

Enhancing the reliability of particulate matter sensing by multivariate Tobit model using weather and air quality data.

Low-cost particulate matter (PM) sensors have been widely used following recent sensor-technology advancements; however, inherent limitations of low-cost monitors (LCMs), which operate based on light scattering without an air-conditioning function, still restrict their applicability. We propose a regional calibration of LCMs using a multivariate Tobit model with historical weather and air quality data to improve the accuracy of ambient air monitoring, which is highly dependent on meteorological conditions, local climate, and regional PM properties. Weather observations and PM2.5 (fine inhalable particles with diameters ≤ 2.5 µm) concentrations from two regions in Korea, Incheon and Jeju, and one in Singapore were used as training data to build a visibility-based calibration model. To validate the model, field measurements were conducted by an LCM in Jeju and Singapore, where R2 and the error after applying the model in Jeju improved (from 0.85 to 0.88) and reduced by 44% (from 8.4 to 4.7 µg m-3), respectively. The results demonstrated that regional calibration involving air temperature, relative humidity, and other local climate parameters can efficiently correct the bias of the sensor. Our findings suggest that the proposed post-processing using the Tobit model with regional weather and air quality data enhances the applicability of LCMs.

Nonlinear Dynamic Analysis of a Piezoelectric Energy Harvester with Mechanical Plucking Mechanism.

In this study, we propose an analytical approach based on the modified differential transform method to investigate the dynamic behavior of a plucking energy harvester. The harvester consists of a piezoelectric cantilever oscillator and a rotating plectrum. The analytical approach provides a closed-form solution that helps determine the starting and ending points of the contact phase between the piezoelectric cantilever and the plectrum. This analytical approach is valuable for simulating complex dynamic interferences in multiple or periodic plucking processes. To evaluate the effects of plucking speed and overlap length of the plectrum on single and periodic plucking, a series of simulations were carried out. The output voltage of the piezoelectric energy harvester increases as the overlap length of the plectrum increases. On the other hand, increasing the plucking speed tends to amplify the magnitude of the contact force while reducing the duration of the contact phase. Therefore, it is crucial to optimize the plucking speed to achieve the maximum linear impulse. For periodic plucking, successful synchronization between the motions of the piezoelectric energy harvester and the rotating plectrum must occur within a limited contact zone. Otherwise, dynamic interferences often cause the plectrum to fail to pluck the energy harvester exactly within the contact zone. Additionally, reducing the plucking speed of the plectrum and increasing the overlap length would be more advantageous for successful periodic-plucking energy harvesting.

Effects of Exercise Intervention (with and without Joint Mobilization) in Patients with Adhesive Capsulitis: A Systematic Review and Meta-Analysis.

This review aimed to investigate the effects of exercise and exercise with joint mobilization on shoulder range of motion (ROM) and subjective symptom recovery in patients with adhesive capsulitis (AC). Related Studies published from 2000 to 2021 that were peer-reviewed and for which pre-and post-values could be calculated were extracted from PubMed, CINAHL, SPORTDiscus, and Web of Science. Nine studies met our inclusion criteria. As a result of calculating the standard mean difference (SMD) and 95% confidence intervals (CI), both exercise and exercise with joint mobilization showed a large effect on shoulder ROM and subjective outcomes. The combination showed a more significant effect than exercise alone on shoulder flexion (SMD = -1.59 [-2.34, -0.65]), extension (SMD = -1.47 [-2.05, -0.89]), internal rotation (SMD = -1.77 [-2.17, -1.36], external rotation (SMD = -2.18 [-2.92, -1.44]), and abduction ROM (SMD = -1.99 [CI -3.86, -0.12]). Patients who performed exercise alone showed a higher effect of improvement in subjective function (SMD = 3.15 [2.06, 4.24]) and pain (SMD = 4.13 [1.86, 6.41]). Based on these results, an AC rehabilitation exercise program should be developed by adjusting the amount of exercise and joint mobilization by identifying the patient's needs, subjective symptoms, and ROM.

Tearing down the barriers to exercise after mastectomy: a qualitative inquiry to facilitate exercise among breast cancer survivors.

OBJECTIVE: Proper exercise immediately after breast cancer surgery (BCS) may prevent unnecessary physical and psychological decline resulting from the surgery; however, patients' attitude, barriers and facilitators for exercise during this period have not been studied. Hence, this study aims to explore the barriers and facilitators of exercise among patients with breast cancer through multiple interviews immediately after surgery through 4 weeks after BCS. METHODS: We conducted three in-depth interviews of 33 patients with breast cancer within 1 month after BCS. RESULTS: We identified 44 themes, 10 codes and 5 categories from interview results. Physical constraints and psychological resistance were identified as the barriers to exercise, while a sense of purpose and first-hand exercise experience were identified as the facilitators of exercise. By conducting the interviews over the course of 4 weeks after surgery, we monitored patterns of changes in barriers and facilitators over time. Overall, our analyses identified that professional intervention based on the time since surgery and the physical state after BCS is essential. The intervention would counteract the overwhelming psychological resistance in the early weeks by developing a sense of purpose in the later weeks. CONCLUSIONS: We made suggestions for future research and exercise intervention programmes that can benefit breast cancer survivors based on the categories, codes and themes identified in this study.

Spherical Micro/Nano Hierarchical Structures for Energy and Water Harvesting Devices.

Three-dimensional (3D) hierarchical structures have been explored for various applications owing to the synergistic effects of micro- and nanostructures. However, the development of spherical micro/nano hierarchical structures (S-HSs), which can be used as energy/water harvesting systems and sensing devices, remains challenging owing to the trade-off between structural complexity and fabrication difficulty. This paper presents a new strategy for facile, scalable S-HS fabrication using a thermal expansion of microspheres and nanopatterned structures. When a specific temperature is applied to a composite film of microspheres and elastomers with nanopatterned surfaces, microspheres are expanded and 3D spherical microstructures are generated. Various nanopatterns and densities of spherical microstructures can thereby be quantitatively controlled. The fabricated S-HSs have been used in renewable electrical energy harvesting and sustainable water management applications. Compared to a triboelectric nanogenerator (TENG) with bare film, the S-HS-based TENG exhibited 4.48 times higher triboelectric performance with high mechanical durability. Furthermore, an S-HS is used as a water harvesting device to capture water in a fog environment. The water collection rate is dramatically enhanced by the increased surface area and locally concentrated vapor diffusion flux due to the spherical microstructures.

Harmonic balance analysis of magnetically coupled two-degree-of-freedom bistable energy harvesters.

Because a magnetically coupled two-degree-of-freedom bistable energy harvester (2-DOF MCBEH) shows the rich, complicated nonlinear behaviors caused by its coupled cubic nonlinearities, understanding the dynamics remains challenging. This paper reports and investigates the important nonlinear dynamical phenomena of the 2-DOF MCBEHs by performing the harmonic balance analysis (HBA). All periodic solution branches are identified in order to study and comprehend the complicated dynamics of the 2-DOF MCBEHs. This end requires care when truncating the harmonic balance solution. For a 1-DOF MCBEH, which is the conventional type, the fundamental harmonic is able to approximately describe the steady-state periodic response. However, high-order harmonics are significant for the 2-DOF MCBEH. This paper demonstrates that the harmonic balance solution should involve the high-order terms instead of using the oversimplified single-harmonic solution. By performing the proposed HBA, important solution branches are reported, and their dynamical behaviors are studied. Moreover, the complete architecture of the frequency response of the 2-DOF MCBEH is disclosed across the entire frequency range. The HBA also reveals the underlying physics of building a bridge between the first and second primary resonant areas under a strong excitation. In the future, the findings in the present report can be utilized in the design process of the 2-DOF MCBEHs.

Evaluation of eye response using a wearable display with automatic interpupillary distance adjustment.

In this study, we introduce a design for a near-eye, wearable display (HMD: head mounted display) that can automatically control the user's interpupillary distance (IPD). In addition, we demonstrate a test-bed module for the wearable AR display based on proposed design. Both the adjustment accuracy and the viewing effect through distance matching between the user's eyes are evaluated by the user's experience in actual wearing of the module. We demonstrate that the distance between the left and right eye pupils can be measured and adjusted using a set of IR camera sensors and a micro-actuator module that we proposed. A half-mirror unit to be mechanically controlled for each eye is designed to combine the image displayed from the projector and an image taken by the IR camera, leading to fine adjustment of the user's IPD. A set of images taken by the IR camera sensors is image-processed in real time to determine each pupil's position with high accuracy under infrared light illumination. Based on the measured information, a micro-actuator module we fabricated for the test bed can automatically adjust the binocular distance to fit each viewer's IPD. The maximum movement distance of each micro-actuator motor is ±10 mm with precision control of at least 0.5 mm. It takes about 18 seconds to calculate the user's IPD from two IR photographs and then to accurately adjust the actual binocular distance of the module that the participant wears. Using the demonstrated test bed, a total of 50 subjects participated to confirm the accuracy in the automatic IPD adjustment with an error of 0.25% as well as the improvement of the displayed image quality and 3D immersive experience.

Machine learning-assisted optimization of TBBPA-bis-(2,3-dibromopropyl ether) extraction process from ABS polymer.

The increasing amount of e-waste plastics needs to be disposed of properly, and removing the brominated flame retardants contained in them can effectively reduce their negative impact on the environment. In the present work, TBBPA-bis-(2,3-dibromopropyl ether) (TBBPA-DBP), a novel brominated flame retardant, was extracted by ultrasonic-assisted solvothermal extraction process. Response Surface Methodology (RSM) achieved by machine learning (support vector regression, SVR) was employed to estimate the optimum extraction conditions (extraction time, extraction temperature, liquid to solid ratio) in methanol or ethanol solvent. The predicted optimum conditions of TBBPA-DBP were 96 min, 131 mL g-1, 65 °C, in MeOH, and 120 min, 152 mL g-1, 67 °C in EtOH. And the validity of predicted conditions was verified.

Development of a 24-Hour Movement Behavior Questionnaire for Youth: Process and Reliability Testing.

OBJECTIVE: To develop and evaluate the reliability of a 24-hour movement behavior questionnaire for physical activity, sedentary behavior, and sleep for youth in South Korea. DESIGN: Mixed-methods study using literature review, expert panels, pilot tests, and test-retest reliability. SETTING: Seoul and Gyeongg-do, South Korea. PARTICIPANTS: A convenience sample of middle and high school students for a pilot test (n = 120) and reliability testing (n = 147). MAIN OUTCOME MEASURES: The reliability of a 24-hour movement behavior questionnaire. ANALYSIS: Cohen's kappa, Spearman, and intraclass correlation coefficients for test-retest reliability testing. RESULTS: The questionnaire consisted of 19 questions in 5 categories: general information, sleep and nap, active transportation-related activity, school life, and free-time activities. The 24-hour movement behavior questionnaire achieved moderate reliability for all sleep, physical activity, and sedentary (r = 0.79, 0.61, 0.56). The amount of sleep, physical activity, and sedentary behavior indicated moderate-to-good rest-retest reliability, with intraclass correlation coefficients ranging from 0.54 to 0.79 (P < 0.01). CONCLUSIONS AND IMPLICATIONS: The 24-hour movement behavior questionnaire was reliable for measuring sleep, physical activity, and sedentary behavior in Korean adolescents aged 13-17 years. The development of this questionnaire could facilitate more accurate and useful measurements of adolescent's activities and lifestyles in South Korea.

Hygroscopic properties of particulate matter and effects of their interactions with weather on visibility.

The hygroscopic property of particulate matter (PM) influencing light scattering and absorption is vital for determining visibility and accurate sensing of PM using a low-cost sensor. In this study, we examined the hygroscopic properties of coarse PM (CPM) and fine PM (FPM; PM2.5) and the effects of their interactions with weather factors on visibility. A censored regression model was built to investigate the relationships between CPM and PM2.5 concentrations and weather observations. Based on the observed and modeled visibility, we computed the optical hygroscopic growth factor, [Formula: see text], and the hygroscopic mass growth, [Formula: see text], which were applied to PM2.5 field measurement using a low-cost PM sensor in two different regions. The results revealed that the CPM and PM2.5 concentrations negatively affect visibility according to the weather type, with substantial modulation of the interaction between the relative humidity (RH) and PM2.5. The modeled [Formula: see text] agreed well with the observed [Formula: see text] in the RH range of the haze and mist. Finally, the RH-adjusted PM2.5 concentrations based on the visibility-derived hygroscopic mass growth showed the accuracy of the low-cost PM sensor improved. These findings demonstrate that in addition to visibility prediction, relationships between PMs and meteorological variables influence light scattering PM sensing.

How the saline water intrusion has reshaped the agricultural landscape of the Vietnamese Mekong Delta, a review.

Once a key factor behind Vietnam's successful Doi Moi (restoration) economic reforms, the rice-centered agriculture of the VMD is now confronted by the new pressure of climate change impacts, including the intensifying salinity intrusion (SI). The SI menace has partly triggered the delta-wide emergence of new adaptive livelihood models across the VMD, including the prawn rice rotational crop (PRRC) that is arguably the most prominent. Research on the SI-driving factors is rapidly increasing in numbers, yet little synthesis has been done. Likewise, several studies have investigated the economic benefits of PRRC; less emphasis has placed on environmental and societal aspects, hence the questionable sustainability. This study, therefore, contributes a composite literature review, targeting two SI-related aspects: (i) key factors driving the intensification of SI in recent years across the Mekong Delta, and (ii) current understanding of the sustainability of PRRC. Results from the first review assignment highlight the four key SI-driving factors: riverbed incision, land subsidence, upstream dams, and sea-level rise. Also remarked are the critical absence of studies addressing multiple drivers and the need for a decoupling model to quantify the relative importance of each factor to strategize the adaptive measures. For PRRC, we reveal that while economic benefits have been widely reported, potential negative impacts of this model related to environmental and social aspects are lacking. Therefore, while the lucrative prawn trade might financially benefit the farmers', the economic benefit is marred by the underlying negative environmental impacts and social inequalities, limiting overall sustainability. This study also provides a case study to notify the spatial-temporal trends of PRRC in the last three decades and evaluate the associated geographical and social factors. Kien Giang province was selected as the study site since it is the largest PRRCacross the VMD. The lessons from Kien Giang can also be applied to other transformative agricultural models in both Mekong Delta and other deltas worldwide.

TiO2 Nanorods and Pt Nanoparticles under a UV-LED for an NO2 Gas Sensor at Room Temperature.

Because the oxides of nitrogen (NOx) cause detrimental effects on not only the environment but humans, developing a high-performance NO2 gas sensor is a crucial issue for real-time monitoring. To this end, metal oxide semiconductors have been employed for sensor materials. Because in general, semiconductor-type gas sensors require a high working temperature, photoactivation has emerged as an alternative method for realizing the sensor working at room temperature. In this regard, titanium dioxide (TiO2) is a promising material for its photocatalytic ability with ultraviolet (UV) photonic energy. However, TiO2-based sensors inevitably encounter a problem of recombination of photogenerated electron-hole pairs, which occurs in a short time. To address this challenge, in this study, TiO2 nanorods (NRs) and Pt nanoparticles (NPs) under a UV-LED were used as an NO2 gas sensor to utilize the Schottky barrier formed at the TiO2-Pt junction, thereby capturing the photoactivated electrons by Pt NPs. The separation between the electron-hole pairs might be further enhanced by plasmonic effects. In addition, it is reported that annealing TiO2 NRs can achieve noteworthy improvements in sensing performance. Elucidation of the performance enhancement is suggested with the investigation of the X-ray diffraction patterns, which implies that the crystallinity was improved by the annealing process.

Load Resistance Optimization of a Magnetically Coupled Two-Degree-of-Freedom Bistable Energy Harvester Considering Third-Harmonic Distortion in Forced Oscillation.

In this study, the external load resistance of a magnetically coupled two-degree-of-freedom bistable energy harvester (2-DOF MCBEH) was optimized to maximize the harvested power output, considering the third-harmonic distortion in forced response. First, the nonlinear dynamic analysis was performed to investigate the characteristics of the large-amplitude interwell motions of the 2-DOF MCBEH. From the analysis results, it was found that the third-harmonic distortion occurs in the interwell motion of the 2-DOF MCBEH system due to the nonlinear magnetic coupling between the beams. Thus, in this study, the third-harmonic distortion was considered in the optimization process of the external load resistance of the 2-DOF MCBEH, which is different from the process of conventional impedance matching techniques suitable for linear systems. The optimal load resistances were estimated for harmonic and swept-sine excitations by using the proposed method, and all the results of the power outputs were in excellent agreements with the numerically optimized results. Furthermore, the associated power outputs were compared with the power outputs obtained by using the conventional impedance matching technique. The results of the power outputs are discussed in terms of the improvement in energy harvesting performance.

A rotationally focused flow (RFF) microfluidic biosensor by density difference for early-stage detectable diagnosis.

Label-free optical biosensors have received tremendous attention in point-of-care testing, especially in the emerging pandemic, COVID-19, since they advance toward early-detection, rapid, real-time, ease-of-use, and low-cost paradigms. Protein biomarkers testings require less sample modification process compared to nucleic-acid biomarkers'. However, challenges always are in detecting low-concentration for early-stage diagnosis. Here we present a Rotationally Focused Flow (RFF) method to enhance sensitivity(wavelength shift) of label-free optical sensors by increasing the detection probability of protein-based molecules. The RFF is structured by adding a less-dense fluid to focus the target-fluid in a T-shaped microchannel. It is integrated with label-free silicon microring resonators interacting with biotin-streptavidin. The suggested mechanism has demonstrated 0.19 fM concentration detection along with a significant magnitudes sensitivity enhancement compared to single flow methods. Verified by both CFD simulations and fluorescent flow-experiments, this study provides a promising proof-of-concept platform for next-generation lab-on-a-chip bioanalytics such as ultrafast and early-detection of COVID-19.

Understanding Interdependencies between Mechanical Velocity and Electrical Voltage in Electromagnetic Micromixers.

Micromixers are critical components in the lab-on-a-chip or micro total analysis systems technology found in micro-electro-mechanical systems. In general, the mixing performance of the micromixers is determined by characterising the mixing time of a system, for example the time or number of circulations and vibrations guided by tracers (i.e., fluorescent dyes). Our previous study showed that the mixing performance could be detected solely from the electrical measurement. In this paper, we employ electromagnetic micromixers to investigate the correlation between electrical and mechanical behaviours in the mixer system. This work contemplates the "anti-reciprocity" concept by providing a theoretical insight into the measurement of the mixer system; the work explains the data interdependence between the electrical point impedance (voltage per unit current) and the mechanical velocity. This study puts the electromagnetic micromixer theory on a firm theoretical and empirical basis.

Exploring the Formation of Exercise Habits with the Latent Growth Model.

This study investigated the antecedent factors affecting exercise preparation and performance habits and provides basic data for the development of health promotion interventions, based on what was found to be most effective in improving intention and habit. The participants were 114 university students who were willing to participate regularly in exercise and physical activities and interested in forming exercise habits. After coding, we analyzed the complete data set through frequency analysis, reliability, and latent growth model analysis. The provision of early rewards positively affected an initial exercise preparation habit. Both initial consistency and development of consistency also positively affected the development of exercise preparation, and initial behavioral complexity positively affected initial exercise preparation. However, no factors influenced an exercise performance habit. Thus, forming an exercise preparation habit requires fun, personal control, and repetitive behavior while forming an exercise performance habit is particularly challenging. These results may help construct a program for continuous exercise participation.

Mechanism of bone-conducted hearing: mathematical approach.

For better understanding of bone-conducted (BC) hearing, a mechanical BC model is formulated using the Wentzel-Kramers-Brillouin (WKB) method. The BC hearing can be generally described by three main mechanisms: (1) cochlear fluid inertia, (2) in-phase motion of the outer bony shell, and (3) out-of-phase motion of the outer bony shell. Specifically, the second and third mechanisms can be identically explained by symmetric pressure compression-expansion and anti-symmetric compression-expansion, respectively. In this study, simulation results show that both the symmetric and anti-symmetric compression-expansion modes become significant at frequencies above 7 kHz while the fluid inertial mode is dominant at lower frequencies. The density difference between the scala fluid and soft cells of basilar membrane and the amplitude of the anti-symmetric compression-expansion input are identified as the difference between the air conduction and bone conduction. The natural frequency of the cochlear duct wall determines the magnitudes between the three mechanism and is approximated to be in the order of 10 MHz and above.

Recent Progress in the Chemistry of Pyridazinones for Functional Group Transformations.

While N-hetereocycles have received significant attention in organic synthesis and other research fields, the chemistry of pyridazine, a six-membered aromatic ring with two adjacent nitrogen atoms, and its derivatives has been relatively little understood. This Synopsis describes recent progress made in the synthesis of pyridazine derivatives-particularly, pyridazin-3(2H)-ones-and their utility as efficient and recyclable functional group carriers for various important organic reactions.

The Effect of Backpack Load Carriage on the Kinetics and Kinematics of Ankle and Knee Joints During Uphill Walking.

The purpose of this study was to investigate the effect of load carriage on the kinematics and kinetics of the ankle and knee joints during uphill walking, including joint work, range of motion (ROM), and stance time. Fourteen males walked at a self-selected speed on an uphill (15°) slope wearing military boots and carrying a rifle in hand without a backpack (control condition) and with a backpack. The results showed that the stance time significantly decreased with backpack carriage (p < .05). The mediolateral impulse significantly increased with backpack carriage (p < .05). In the ankle joints, the inversion-eversion, and dorsi-plantar flexion ROM in the ankle joints increased with backpack carriage (p < .05). The greater dorsi-plantar flexion ROM with backpack carriage suggested 1 strategy for obtaining high plantar flexor power during uphill walking. The result of the increased mediolateral impulse and inversion-eversion ROM in the ankle joints indicated an increase in body instability caused by an elevated center of mass with backpack carriage during uphill walking. The decreased stance time indicated that an increase in walking speed could be a compensatory mechanism for reducing the instability of the body during uphill walking while carrying a heavy backpack.