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The Cassie–Baxter state of wetting explains a large equilibrium contact angle and the slippery dynamics of a water droplet on a superhydrophobic rough surface. It also causes a contact angle hysteresis (CAH) that cannot be fully described by dynamic wetting theories including the molecular kinetic theory (MKT). We analyze the contact line dynamics on a superhydrophobic surface in the framework of the MKT. Multi-body dissipative particle dynamics simulations of a capillary bridge confined between two rough surfaces under steady shear are performed. We find that, in addition to the contact line friction force from the MKT, an additional friction force contribution is needed on rough surfaces. It can be obtained by subtracting from the total friction force the force solely caused by the actual liquid–solid contact area. We find that the additional force is almost constant at all contact line velocities. Thus, it is directly related to the CAH. The CAH originates not only from contact line pinning but also from the shear flow due to the strong friction in the central region of the liquid–solid interface away from the contact line. The analysis of the particle flow inside the capillary bridge shows that liquid particles trapped in the grooves of the surface texture actually move with the same velocity as the surface and exert strong additional friction to other liquid particles. This work extends the MKT to rough surfaces, as well as to elucidate the origin of the CAH of a capillary bridge. The finding would help to better understand other situations of dynamic wetting on superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

C60 is a nanomaterial produced from the pyrolysis of hydrocarbons that needs to be extracted and purified to obtain the desired properties. Previous studies reported purification as the environmental hotspot of the C60 production process. However, no study has evaluated existing C60 purification methods and proposed alternatives based on environmental, cost, and chemical hazards. Here we used life cycle assessment (LCA) and evaluated the most common existing C60 purification methods (chromatography-crystallization, crystallization, & complexation) and identified selective complexation with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the greenest existing C60 purification technique that has less environmental (70% from chromatography-crystallization & 50% from crystallization), cost (70% from chromatography-crystallization & 80% from crystallization), and chemical (30% from chromatography-crystallization & crystallization) hazards. The solvent (1,2,4-trymethylbenzene (TMB)) was identified as the environmental hotspot contributing to more than 95% of the cumulative energy demand (CED) of the complexation process. We employed green chemistry principles and an iterative approach to assess the performance of potential replacements (linseed oil, olive oil, toluene, & xylene) for TMB. Although we evaluated solvents that are expected to be greener than petroleum-based solvents, we determined toluene as the greenest alternative. Compared to the baseline complexation method, using toluene reduced the environmental impact by 59%, cost by 85%, and chemical hazards by 42%. Identifying toluene as the alternative green solvent for C60 purification can reduce the carbon footprint of C60-containing products used for various emerging applications, such as solar cells, hydrogen storage, biofuels, etc., which aligns with current decarbonization strategies. [ABSTRACT FROM AUTHOR]

The photon upconversion (UC) is the process that has been known for a long time. Especially, lanthanide-based UC materials recently have attracted huge interest of scientific community due to their narrow visible emission bands upon near-infrared (NIR) excitation. However, the excitation in the high excitation power of NIR can cause highly bright and broad emission (B-UC). Such explosive B-UC was distinct at high excitation condition with UC wavelength encompassing the entire visible range. Previously, the proposed model of B-UC origination includes heat, multi-photon absorption, and accumulated thermal energy transfer. In this article, we will show various experimental and theoretical evidence supporting the idea that B-UC arises from photophysical pathways. Here, the key experimental evidence for photophysical pathways model of B-UC is to measure B-UC in the low-temperature environment (22 K). In addition, the density functional theory was used to regenerate energy levels which would be compared to the absorption spectral bands in Er2O3. As a result, we are confident of an electron tunneling model from 2P3/2 of Er3+ to oxygen vacancy level (VO) of Er2O3. Then, VO electrons are sequentially excited to the conduction band of Er2O3 by energy transfer from 4F9/2 of Er3+. Finally, the electrons return to the VO of Er2O3 with concomitant B-UC. [ABSTRACT FROM AUTHOR]

One distinguishing feature in terms of national curriculum revisions is the emphasis on invention education in the subject of technology. This study investigates how South Korean middle school students perceive inventors. A manufactured tool for testing and a checklist for evaluating images of inventors were created to assess drawings of 115 8th grade students. The final 108 surveys (from 52 male and 56 female students) were analyzed, and the results were quite similar to those of prior studies that examined how students picture scientists. This research confirmed that students had stereotypical images of inventors. Stereotypical elements that were not depicted in prior studies were also discovered. For example, tools such as spanners, hammers, and screwdrivers, which are used for building and fixing things, were proposed as symbols of research by students. Overcoming such stereotypical representations requires improving stereotypical images of inventors as they are presented in photos and figures of textbooks, developing and implementing educational programs that introduce relevant images of inventors, and changing teachers' recognition. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although commonly utilized treatments, no study has directly compared the effectiveness of joint mobilization and stabilization exercise in individuals with forward head posture (FHP). OBJECTIVE: This study aimed to investigate the effects of upper cervical and upper thoracic spine mobilization versus deep cervical flexors exercise (DCFE) in individuals with FHP. METHODS: Thirty-one participants with FHP were randomized into the mobilization (n = 15) or exercise (n = 16) group. The treatment period was 4 weeks with follow-up assessment at 4 weeks and 6 weeks after the initial examination. Outcomes assessed included the craniovertebral angle (CVA), numeric pain rating scale (NPRS), respiratory function, and the global rating of change (GRC). RESULTS: Participants in the mobilization group demonstrated significant improvements (p < 0.05) in CVA, NPRS, and respiratory function, as compared to those in the exercise group. In addition, 9 of 15 (60%) participants in the mobilization group, as compared to 4 of 16 participants (25%) in the exercise group, had a GRC score of + 4 or higher. CONCLUSIONS: The combination of upper cervical and upper thoracic spine mobilization indicated better overall short-term outcomes in CVA, NPRS, respiratory function, and GRC compared with DCFE in individuals with FHP. [ABSTRACT FROM AUTHOR]

Background: Although commonly used in clinical settings, evidence regarding the beneficial effectiveness of joint mobilization and therapeutic exercise in patients with stroke is still lacking.Objective: This study aimed to investigate the effects of mid-thoracic spine mobilization and therapeutic exercise on dynamic balance and inspiratory function in patients with subacute stroke.Methods: The participants included 33 patients with subacute stroke. Participants were randomly allocated to 1 of 2 groups: (1) a group that received segmental mobilization (T4-8), and (2) a group that received foam roller exercises (T4-8). Outcome measure included the limits of stability (LOS), inspiratory function, and global rating of change (GRC).Results: The improvement in inspiratory function was statistically significant at 4 and 6 weeks after the initiation of the intervention and changes in the LOS were statistically significant at 6 weeks in the mobilization group (p< 0.05). In addition, 15 of 17 (88.2%) participants in the mobilization group, compared to 9 of 16 participants (56.2%) in the exercise group, indicated a GRC score of +4 or higher at the 4-week follow-up.Conclusions: This study demonstrates that patients with subacute stroke who receive mid-thoracic spine mobilization demonstrate effective short-term improvements in LOS and GRC. [ABSTRACT FROM AUTHOR]

Background: Re-deviation of the nasal septum may occur after septoplasty. Because the cartilaginous septum grows until the age of 16-17 years, septoplasty is usually recommended thereafter. However, severely deviated septum may necessitate septoplasty in younger adolescents. Objectives: To compare the incidence of re-deviated nasal septum in patients who underwent septoplasty at ≤18 versus ≥19 years of age. Materials and methods: The medical records and endoscopic photographs of patients who underwent septoplasty between 2005 and 2015 were retrospectively reviewed. Re-deviation of the nasal septum was defined as >50% narrowing of one side of the nasal cavity compared to immediately after septoplasty. Results: The inclusion criteria were met by 52 adolescent patients and 549 adult patients. Re-deviation of the septum occurred in 11 (21.2%) and 39 (7.1%) patients, respectively; the difference was significant. Most patients had caudal and upper cartilaginous deviations. Four adolescent and 14 adult patients underwent revisional septoplasty. Conclusions and significance: Adolescent patients who underwent septoplasty had a significantly higher incidence of re-deviation of the nasal septum than adult patients. Therefore, when septoplasty is deemed necessary in adolescent patients, they and their parents should be informed about the possibility of re-deviation and the need for revisional septoplasty. [ABSTRACT FROM AUTHOR]

This study investigated the gender difference among South Korean high school students in science learning motivation, technology learning motivation, and concern related engineering, as well as the correlation between these factors. It also verified effects of the sub-factors of science learning motivation and technology learning motivation on concern related to engineering. For this study, 745 students in grade 11th at six high schools in South Korea were involved as subjects in a survey conducted using instruments developed by Glynn et al. and Hall et al. In the results, a gender difference was observed in some sub-factors related to science learning motivation and technology learning motivation, and a positive correlation was found between most of the sub-factors of science learning motivation and technology learning motivation and concern related to engineering. Moreover, intrinsic motivation and personal relevance in technology were major factors that influenced students' concern related to engineering. Based on the findings, this study demonstrates the educational implications of including engineering in high school technology curriculums. [ABSTRACT FROM AUTHOR]

A variety of linear polymer precursors with hydrogen bonding motifs at both ends enable us to design supramolecular polymer systems with tailored macroscopic properties including self-healing. In this study, we investigate thermodynamic properties of single polyethylene and polybutylene glycols with hydrogen bonding motifs. In this context, we first build a coarse-grained model of building blocks of the supramolecular polymer system based on all-atom molecular structures. The density of states of the single precursor is obtained using the stochastic approximation Monte Carlo method. Constructing canonical partition functions from the density of states, we find the transition from looped to open conformations at transition temperatures which are non-monotonously changing with an increasing degree of polymerization due to the competition between chain stiffness and loop-forming entropy penalty. In the complete range of chain length under investigation, a coexistence of the looped and open morphologies at the transition temperature is shown regardless of whether the transition is first-order-like or continuous. Polyethylene and polybutylene glycols show similar behavior in all the thermodynamic properties but the transition temperature of the more flexible polybutylene glycol is shown to change more gradually. [ABSTRACT FROM AUTHOR]

Diffusion of long ring polymers in a melt is much slower than the reorganization of their internal structures. While direct evidence for entanglements has not been observed in the long ring polymers unlike linear polymer melts, threading between the rings is suspected to be the main reason for slowing down of ring polymer diffusion. It is, however, difficult to define the threading configuration between two rings because the rings have no chain end. In this work, evidence for threading dynamics of ring polymers is presented by using molecular dynamics simulation and applying a novel analysis method. The simulation results are analyzed in terms of the statistics of persistence and exchange times that have proved useful in studying heterogeneous dynamics of glassy systems. It is found that the threading time of ring polymer melts increases more rapidly with the degree of polymerization than that of linear polymer melts. This indicates that threaded ring polymers cannot diffuse until an unthreading event occurs, which results in the slowing down of ring polymer diffusion. [ABSTRACT FROM AUTHOR]

• Evaluate organic transparent photovoltaics (TPV) for buildings in the US. • Transparent photovoltaics produce electricity and reduce energy consumption. • Life cycle assessment is used to calculate the net energy benefit. • The energy payback time varies from 51 days to 1.1 years depending on the location. Transparent photovoltaics is a new technology that can be used in buildings applications to simultaneously save energy and produce electricity. This study evaluates the potential of transparent photovoltaic (TPV) in window and skylight applications for four cities in the United States: Detroit, Los Angeles, Phoenix and Honolulu. Building energy demand simulation, photovoltaic generation, and life cycle assessment (LCA) are combined to evaluate the net energy benefit (NEB). The use of TPV on windows is evaluated for both new windows, for which the solar cell is deposited in the interior surface of the glass pane, and for the refurbishment of existing windows, for which plastic encapsulated solar cells are placed on the interior surface of existing windows. The NEB was found to be positive for all scenarios considered, and the cradle to gate energy to manufacture a transparent organic photovoltaic module was found to be negligible. The NEB was used to calculate the energy return on investment (EROI) and the energy payback time (EPBT). Both were found to be either better or comparable to other photovoltaic technologies. For glass modules, the best EROI was 102 in Phoenix for window and 208 in Honolulu for skylights. The EPBT varied from 51 days to 1.1 years, depending on the location and type of module. The use of transparent photovoltaics in the US was found to have both environmental and cost benefits due to the combined reduction in building energy consumption and electricity production. [ABSTRACT FROM AUTHOR]

Most photophysical studies in the halide perovskite have focused on the characteristics of the surface. However, the photons generated at the surface would be absorbed by the same material (re-absorption), and the photophysics of re-absorbed photons are rarely studied. Herein, we present our recent observation of the re-emission (photoluminescence after re-absorption, IR) in Cs4PbBr6, which is temporally slower than the surface-emission (IS). We performed a characterization of Cs4PbBr6, a power dependence experiment, and a lifetime measurement to reveal the emitting properties of Cs4PbBr6. However, we characterized the first re-emission (re-emission after first re-absorption, IFR) of Cs4PbBr6. The analysis of IFR revealed that the energy intervals between IS and IFR and between IFR and final re-emission (IR) are close to integer multiples. Therefore, we suggested that the least number of repeated re-absorptions required for generating IR is three. [ABSTRACT FROM AUTHOR]

Abnormally slower diffusional processes than its internal structure relaxation have been observed in ring polymeric melt systems recently. A key structural feature in ring polymer melts is topological constraints which allow rings to assume a threading configuration in the melt phase. In this work, we constructed a lattice model under the assumption of asymmetric diffusivity between two threading rings, and investigated a link between the structural correlation and its dynamic behavior via Monte Carlo simulations. We discovered that the hierarchical threading configurations render the whole system to exhibit abnormally slow dynamics. By analyzing statistical distributions of timescales of threading configurations, we found that the decoupling between internal structure relaxation and diffusion is crucial to understand the threading effects on the dynamics of a ring melt. In particular, in the limit of small but threaded rings, scaling exponents of the diffusion coefficient D and timescale τ diff with respect to the degree of polymerization N agree well with that of the annealed tree model as well as our mean-field analysis. As N increases, however, the ring diffusion abruptly slows down to the glassy behavior, which is supported by a breakdown of the Stokes–Einstein relation. [ABSTRACT FROM AUTHOR]

Objectives To our knowledge, the influence of sleep deprivation on hearing levels has yet to be assessed in animals. Therefore, we evaluated whether auditory function was affected by sleep deprivation in rats. Methods Male Wistar rats (aged 9 weeks, weighing 300–400 g) were used for the study and were randomly assigned to a control (n = 15) or sleep deprivation group (n = 12). Hearing levels were evaluated at baseline and 9 days after sleep deprivation using auditory evoked brainstem responses (ABRs) and distortion product otoacoustic emission (DPOAE) measurements. Blood was collected for the measurement of interleukin-1β and corticosterone levels. Results The ABR thresholds (at 8, 16, and 32 kHz) at 9 days were significantly elevated in the sleep deprivation group compared to the control group ( p  < 0.05, respectively). The sleep deprivation group showed a defect in the function of outer hair cells, as evidenced by decreased levels of distortion product otoacoustic emission. IL-1β was significantly increased in the sleep deprivation group. Sleep-deprived rats exhibited rupture of Reissner's membrane and morphological damage to stereocilia. Conclusion These results suggest that sleep deprivation induces damage to the cochlea and results in hearing loss in Wistar rats. [ABSTRACT FROM AUTHOR]

Background: Although upper cervical and upper thoracic spine mobilization plus therapeutic exercises are common interventions for the management of forward head posture (FHP), no study has directly compared the effectiveness of cervical spine mobilization and stabilization exercise with that of thoracic spine mobilization and mobility exercise in individuals with FHP.Methods: Thirty-two participants with FHP were randomized into the cervical group or the thoracic group. The treatment period was 4 weeks, with follow-up assessment at 4 and 6 weeks after the initial examination. Outcome measures including the craniovertebral angle (CVA), cervical range of motion, numeric pain rating scale (NPRS), pressure pain threshold, neck disability index (NDI), and global rating of change (GRC) were collected. Data were examined with a two-way repeated-measures analysis of variance (group × time).Results: Participants in the thoracic group demonstrated significant improvements (p < .05) in CVA, cervical extension, NPRS, and NDI at the 6-week follow-up compared with those in the cervical group. In addition, 11 of 15 (68.8%) participants in the thoracic group compared with 8 of 16 participants (50%) in the cervical group showed a GRC score of +4 or higher at the 4-week follow-up.Conclusions: The combination of upper thoracic spine mobilization and mobility exercise demonstrated better overall short-term outcomes in CVA (standing position), cervical extension, NPRS, NDI, and GRC compared with upper cervical spine mobilization and stabilization exercise in individuals with FHP.Trial Registration: KCT0002307 , April 11, 2017 (retrospectively registered). [ABSTRACT FROM AUTHOR]

Concentration – discharge (c-q) hysteresis loops are used to qualitatively understand solute transport pathways to streams. The majority of c-q studies involve non-urban areas in environmental settings such as the subtropics, mountains, and high latitude rivers. Only a few involve urban or urban salted watersheds. In this study, we explore c-q hysteresis plots and pollutographs for a variety of inorganic solutes (Cl − , Na + , K + , SiO 2 , NO 3 − ), dissolved organic carbon and an indicator of the aromatic fraction (SUVA 254 ), and a microbiological indicator ( E. coli ) in an urban salted watershed. The major hydrologic events are snow melts. The overarching hypothesis is that the hysteresis behavior can be explained by extending the pathway analysis (i.e., relative importance of storm event water, C SE ; groundwater C G ; and soil water, C SO ) from the Evans-Davis classification scheme that describes six behaviors to account for differences in source locations and the biogeochemical behavior of the solutes along these pathways. Data sets for the years 2013, 2014, and 2015 were assembled from a series of undergraduate and graduate research projects performed over this period. The results of these studies indicate that: 1) Cl − and Na + exhibit a combination of C2 (C SE > C SO > C G ) and C3 (C G > C SE > C SO ) behavior during salting season and A1 (C SO > G G > C SE ) and A2 (C SO > C SE > C G ) behavior in non-salting times; 2) SiO 2 shows A3 (C G > C SO > C SE ) behavior in all events, 3) K + changes from C2 to C1 (C SE > C G > C SO ) with concentration depletion over subsequent events; 4) NO 3 − changes from A2 to C1 or C2 with concentration depletion over subsequent events; 5) DOC and SUVA 254 exhibit C2 and A1 behavior, respectively; 6) E. coli changes from C2 to A2 over subsequent storms; 7) Cl − and Na + peak before the rising limb with a slight lag in the Na + peak and 8) E. coli does not exhibit first-flush behavior. An integrative pollutograph for a snow melt event shows, 1) K + and DOC peak together three times, unrelated to any additional event such as rain; 2) DOC becomes more aliphatic at its first peak, and 3) NO 3 − has a concentration decrease at the second DOC/K + peak and peaks on the declining limb after the third DOC/K + peak. These observations can be explained in terms of the c-q plots (e.g., importance of event water), environmental behavior (e.g., conservative solute), the nature of the urban landscape (e.g., pavement), and season (e.g., damped microbial activity). We interpret the multiple concentration peaks to indicate water masses originating from different compartments in the watershed are reaching the stream at different times and with different chemistries. These results extend the work of previous studies and may serve to help develop a fingerprint of solute behavior that can be used to more fully explore early season biogeochemical dynamics in an urban, salted, snow-melt dominated watershed. [ABSTRACT FROM AUTHOR]

In wafer polishing pad surface plays a crucial role in the polishing process. With the increase of friction time between pad and wafer, the pad becomes flattened or glazed with particles clogging the pores of the pad and forming a layer of slurry residue and wafer particles, leading to changes of COF, material removal rates and higher defects on the wafer surface. Thus, this study aims to determine the correlation between pad surface deformation, slurry adhesive rate and Coefficient of friction (COF) during friction between felt pad and single -crystal silicon, to analyze the relationship between pad condition and COF. The real-time COF between felt pad and single-crystal silicon wafer are tested which are sorted in groups depending on various loads and oscillation frequencies and surfaces of felt pads measuring by Scanning electron microscope (SEM) are compared. The correlation between pad surface deformation and abrasive adhesion and COF is evaluated through analyzing the experiment results. [ABSTRACT FROM AUTHOR]