Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet

[EN] In the present work, we experimentally investigated the effect of initial liquid droplet size on the evaporation in the heterogeneous droplet. Spherical carbon and water were used for particle and liquid droplet comprising the heterogeneous droplet. four initial droplet volumes of 1, 2, 3 and 4 μl were considered when the diameter of the particle was 5 mm. The heterogeneous droplet was suspended with a rod at 20 cm away from the radiator which surface temperature was fixed to 473 K. Ambient temperature and relative humidity remained 296 K and 40 %, respectively, during the experiment. As the results, the evaporation rate of 4 μl case increased about 1.8 times compared with that of 1 μl case. The evaporation rate increased almost linearly with the volume ratio, and that is related closely with the contact surface between particle and water droplet. Contact surface area remained almost constantly with time, whereas it increased with the initial volume of water droplet. The energy from radiator can be accumulated at the contact surface at the side of particle, thereby intensifying the evaporation of water droplet because more heat transfers from particle to droplet through the contact surface. Consequently, the initial volume of liquid droplet is one of the influence factors on the evaporation rate in the heterogenous droplet.This research was supported by the Fire Fighting Safety & 119 Rescue Technology Research and Development Program funded by the Ministry of Public Safety and Security (NEMA-NG-2014-46) and Research Project of Air Sampling Detector funded by Alllitelife co. Inc..Sung, KH.; Nam, JS.; Hong, GB.; Ryou, HS. (2017). Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 290-295. https://doi.org/10.4995/ILASS2017.2017.4744OCS29029

Relationships of walking activity with depressed mood and suicidal ideation among the middle-aged Korean population: a nationwide cross-sectional study

IntroductionThe suicide rate of middle-aged adults has increased rapidly, which is a significant public health concern. A depressed mood and suicidal ideation are significant risk factors for suicide, and non-pharmacological interventions such as exercise therapy have been suggested as potential treatments. Walking is a feasible and accessible form of exercise therapy for middle-aged adults.MethodsWe conducted a study based on the Seventh Korea National Health and Nutrition Examination Survey (2016–2018) data of 6,886 general middle-aged adults in South Korea to investigate the relationships of walking exercise with depressed mood and suicidal ideation. Multiple logistic regression analysis was used to adjust for confounding variables. Sampling weights were applied to obtain estimates for the general Korean population.ResultsParticipants who walked ≥5 days per week had a significantly lower odds ratio (OR) for depressed mood [OR = 0.625, 95% confidence interval (CI): 0.424–0.921, p = 0.018] and suicidal ideation (OR = 0.252, 95% CI: 0.125–0.507, p < 0.001) compared to those who never walked, regardless of the duration of exercise. The same results were obtained for males after stratifying the data by sex and suicidal ideation was associated with walking in females.ConclusionRegular walking exercise was associated with diminished mental health problems in middle-aged adults. Light walks may serve as a useful starting point for patients with serious mental health issues, such as suicidal ideation

A Wearable Wrist Band-Type System for Multimodal Biometrics Integrated with Multispectral Skin Photomatrix and Electrocardiogram Sensors

Multimodal biometrics are promising for providing a strong security level for personal authentication, yet the implementation of a multimodal biometric system for practical usage need to meet such criteria that multimodal biometric signals should be easy to acquire but not easily compromised. We developed a wearable wrist band integrated with multispectral skin photomatrix (MSP) and electrocardiogram (ECG) sensors to improve the issues of collectability, performance and circumvention of multimodal biometric authentication. The band was designed to ensure collectability by sensing both MSP and ECG easily and to achieve high authentication performance with low computation, efficient memory usage, and relatively fast response. Acquisition of MSP and ECG using contact-based sensors could also prevent remote access to personal data. Personal authentication with multimodal biometrics using the integrated wearable wrist band was evaluated in 150 subjects and resulted in 0.2% equal error rate ( EER ) and 100% detection probability at 1% FAR (false acceptance rate) ( PD.1 ), which is comparable to other state-of-the-art multimodal biometrics. An additional investigation with a separate MSP sensor, which enhanced contact with the skin, along with ECG reached 0.1% EER and 100% PD.1 , showing a great potential of our in-house wearable band for practical applications. The results of this study demonstrate that our newly developed wearable wrist band may provide a reliable and easy-to-use multimodal biometric solution for personal authentication

Seasonal Variations of Wind and Temperature at the Mesopause

The Mesopause (85km) is the boundary between the Mesosphere and the Thermosphere and is a very interesting region because there ate active fluid dynamic motions arid airglow phenomena due to various chemical reactions. But there have been not many studies due to the difficulties of insitu measurement. Bowever in this study we have obtained the Doppler temperatures and winds through the observing Hydroxyl(OH) emission at 843nm using a ground-based Fabry-Perot interferometer. Due to the 2 years of long term observation, we can confirm the seasonal Mesopause temperature variation, which is the opposite trend against the temperature at the ground level, and reveal annual and biannual variations for meridional arid zonal wind respectively. These seasonal variations might be the result of the inter-hemispheric circulation

Erdheim–Chester Disease Involving the Biliary System and Mimicking Immunoglobulin G4-Related Disease: A Case Report

First described in 1930 as a lipoid granulomatosis, Erdheim-Chester disease (ECD) is a rare histiocytosis encompassing a group of disorders caused by overproduction of histiocytes, a subtype of white blood cells. This disease most commonly involves the bones and can affect organs in the abdomen; however, biliary involvement is rarely reported. We report a case of ECD with biliary involvement, which rendered it difficult to radiologically distinguish ECD from immunoglobulin G4-related disease

New possibilities in polymer binder jetting additive manufacturing via infiltration and warm isostatic pressing

Binder jetting (BJ) leads to low mechanical properties and high porosity because it uses binders to selectively bind powder materials. To overcome the poor characteristics of BJ parts, infiltration is a generally applied post-process; however, it results in a low infiltration volume and large number of residual voids in the uninfiltrated section. This study aims to effectively improve the mechanical properties, microstructure, and density of polymer-based BJ parts by overcoming limitations of infiltration process via warm isostatic pressing (WIP) that applies heat and pressure. The infiltrated specimens with epoxy are vacuum-packed, and the WIP process is performed at a target temperature of 130 °C and pressure of 8 MPa. Consequently, the infiltration volume increases by up to 195.2%, and the number of residual voids in the uninfiltrated section, where the infiltrants do not reach, is significantly reduced. Further, in terms of the mechanical properties, the tensile strength increases by 1215%, compressive strength by 1280%, and flexural strength by 535%. In addition, the results of transmission, scanning electron microscopy, and microcomputer X-ray tomography reveal a clear decrease in the number of voids

Effects of cashew nut testa levels as an alternative to wheat bran in gestating sow diets

Objective This study was conducted to evaluate the effects of dietary cashew nut testa (CNT) as an alternative feed ingredient to wheat bran on reproductive performance, litter performance, milk composition, and blood profiles of gestating sows. Methods Forth multiparous sows (Yorkshire×Landrace) were fed experimental diets starting at 35 days of pregnancy and an initial average body weight (BW) of 211.53±8.86 kg. Each sow was assigned to a treatment based on BW, backfat thickness (BF) and parity with 10 sows per treatment. Treatments were as follows: i) corn-soybean meal based diet with 6% of wheat bran (C0); ii) basal diet with 2% of CNT and 4% of wheat bran (C2); iii) basal diet with 4% of CNT and 2% of wheat bran (C4); and iv) basal diet with 6% of CNT (C6). Results There were no statistically significant differences in BW and BF of gestating sows throughout the experimental period. However, changes in BF (p = 0.09) and the daily feed intake of sows (p = 0.09) tended to linearly increase during the lactation period. The weaning to estrus interval (WEI) showed a quadratic response to CNT treatment (p = 0.02), and the C2 diet showed the shortest WEI. Litter birth weight (p = 0.04) and piglet birth weight (p = 0.06) were linearly decreased with increase in CNT. Furthermore, there had no significant differences in piglet weight and litter weight in 21 day. Insulin concentration at day 70 of gestation was linearly reduced with increasing CNT level in diets (p = 0.03). Conclusion When 6% CNT replaced wheat bran in gestating sow diets, there were no negative effects on sow performance, but litter birth weight and piglet birth weight were decreased when CNT level increased in gestating sow diets

Potential Therapeutic Effect of Continuous Positive Airway Pressure on Laryngopharyngeal Reflux in Obstructive Sleep Apnea Patients

To investigate the potential therapeutic effect of continuous positive airway pressure (CPAP) treatment on laryngopharyngeal reflux in obstructive sleep apnea (OSA) patients, we performed a retrospective analysis of data prospectively collected from patients who underwent CPAP therapy after being diagnosed with moderate to severe OSA between January 2019 and May 2020. Subjects were asked to complete the reflux symptom index (RSI) questionnaire before and after CPAP. Additionally, a laryngoscopic examination was performed to evaluate objective endoscopic findings and determine reflux finding score (RFS). A total of 46 patients were included in the analysis. Overall, significant decreases in mean RSI score (10.85 ± 6.40 vs. 8.80 ± 7.99, p < 0.001) and RFS (7.41 ± 3.32 vs. 4.65 ± 2.12, p < 0.001) were observed after CPAP treatment. Within subdomains of the RSI, throat clearing, postnasal drip, breathing difficulty, troublesome cough, and foreign body sensation were significantly improved by CPAP treatment. All subdomains of RFS, with the exception of posterior commissure hypertrophy and granuloma, showed significant differences after CPAP treatment. There were no differences between subgroups according to body mass index or severity of OSA. CPAP treatment in OSA potentially reduces laryngeal reflux symptoms and improves laryngeal examination findings