Autor: Li, Jun-Yi - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Intervention effects of greenspace exposure on human microbiota : a randomized controlled trial in Chinese young adults
Autorzy:: Dong, Guang-Hui
Huang, Ji-Lin
Markevych, Iana
Dadvand, Payam
Yang, Bo-Yi
Heinrich, Joachim
Li, Jun-Yi
Chen, Chen
Browing, Matthew H.E.M.
Li, Chuang
Zheng, Zi-Han
Jiang, Jian-Cheng
Zhao, Tian-Yu
Zhu, Xiao-Qi
Wang, Zhi
Wang, Lu
Opis:: Enriching human microbiota has been proposed as a mechanism by which greenspace exposure improves human health. The existing evidence is scarce with few studies able to evaluate causality. We conducted a randomized controlled trial of 30 healthy undergraduate students to explore the intervention effects of greenspace on human gut and oral microbiota alpha-diversity, composition, differential genera and functional pathways. The study participants were divided into three groups, including outdoor greenspace (GS) group, outdoor non-greenspace (NGS) group, and indoor group, who visited a park, an open space without vegetation, and a classroom, respectively, for two hours per day over seven days. Differences in microbial alpha-diversity and composition across various groups were tested using Wilcoxon test and permutational multivariate analysis of variance, respectively. Linear discriminant analysis effect size analysis was performed to test differences in genera and functional pathways. Greenspace intervention significantly increased gut microbiota alpha-diversity, especially the observed Amplicon Sequence variant indexes and the Faith indexes (both p <0.05). In addition, the intervention substantially changed the composition of gut microbiota, of which the relative abundances of potentially beneficial bacteria increased. Further, the greenspace intervention affected several functional pathways of gut microbiota, including "substance dependence", "specific types of cancer", and "viral infectious diseases". However, we did not find any significant effect of greenspace intervention on oral microbiota. Our results suggest that greenspace intervention diversifies the gut microbiota and alters its composition. These findings could help to reinforce the potential of increasing people’s access to greenspace as a public health intervention.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 2.

Tytuł:: Effects of a water hammer and cavitation on vibration transients in a reservoir-pipe-valve system
Autorzy:: Miao, Yang
Qiu, Zaihui
Zhang, Xiaolu
Jiang, Yuncheng
Pan, Jun
Liu, Yi
Zhang, Li
Li, Kun
Tematy:: reservoir-pipe-valve system (RPV system)
water hammer
vibration
cavitation; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/2055065.pdf Link otwiera się w nowym oknie
Opis:: An extraordinary phenomenon with violent oscillation, accompanied by an abnormal “click” sound is observed during the valve closing in a fuel feeding pipe system. A fluctuation model with flow cavitation, in which time-varying stiffness, time-varying damping coefficients and flow cavitation are comprehensively considered, is proposed. On this basis, a dynamic vibration equation is established and an expression of flow pressure at the valve port is derived. The critical displacement of the flow cavitation system is defined. When the vibration amplitude reaches the critical displacement, cavitation occurs. Based on this model, simulation of vibration displacement and flow pressure is given. The simulated transient process shows the phenomena of vibration fluctuation with cavitation. The results are compared with the experimental data measured by a pressure sensor. Under our experimental conditions, the critical displacement of vibration is 1.41mm, and the average relative pressure peak error is 0.022. The comparison between the simulation and experimental results shows that they are in an acceptable agreement.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Rheological Properties of DNAN/HMX Melt-cast Explosives : Maximum Packing Density Calculation and Modified Viscosity Model
Autorzy:: Meng, Jun-jiong
Luo, Yi-ming
Wang, Wei
Jiang, Qiu-li
Wang, Hong-xing
Miao, Fei-chao
Tematy:: 2,4-dinitroanisole
DNAN
grade ratio
maximum packing density
rheological properties
empirical model; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:: https://bibliotekanauki.pl/articles/59115417.pdf Link otwiera się w nowym oknie
Opis:: The study of suspensions with high solid content and low viscosity has become a very active topic for melt-cast explosives, for both research and industry. Previous studies have described how the viscosity of high-solid-content suspensions can be decreased by optimizing the grade ratio, that is, increasing the particle packing density. This paper numerically simulates the maximum packing density (Φm) for different grade ratios at which the suspension viscosity approaches infinity, using the overlapping discrete element cluster method. According to this method, the shape of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) particles was modeled as a group of overlapping, rigidly connected hard spheres. The results showed that the numerical simulation value can be used as the real value of Φm for any grade ratio in engineering applications. The rheological properties of 2,4-dinitroanisole (DNAN)/HMX suspensions with various grade ratios of three HMX samples with different d50 values were investigated using a rotational viscometer over a range of mass solids content (ϕ = 20-75 wt.%) in the shear rate range of 0.1-100 s⁻¹. An empirical model incorporating the reduced solid content (Φ, equal to ϕ divided by Φm) and shear rate (γ) was modified to predict the relative viscosity of DNAN/HMX suspensions. This modified model has a strong correlation with the experimental data and can be used to accurately predict the viscosity of DNAN/HMX suspensions. In addition, the applicability of different classical models to DNAN/HMX suspensions is discussed.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Associations of greenness surrounding schools with blood pressure and hypertension : a nationwide cross-sectional study of 61,229 children and adolescents in China
Autorzy:: Yang, Bo-Yi
Dong, Guang-Hui
Guo, Yuming
Hu, Li-Wen
Ma, Jun
Chen, Ya-Jun
Chen, Gongbo
Luo, Ya-Na
Heinrich, Joachim
Markevych, Iana
Zou, Zhiyong
Browning, Matthew H E M
Bao, Wen-Wen
Ma, Yinghua
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 5.

Tytuł:: Greenness surrounding schools and visual impairment in Chinese children and adolescents
Autorzy:: Huang, Wen-Zhong
Dong, Guang-Hui
Gui, Zhaohuan
Markevych, Iana
Yang, Bo-Yi
Heinrich, Joachim
Xiao, Xiang
Jing, Jin
Ma, Yinghua
Bao, Wen-Wen
Li, Shanshan
Chen, Yajun
Zou, Zhiyong
Bloom, Michael S
Luo, Ya-Na
Ma, Jun
Opis:: Background: Evidence concerning the effects of greenness on childhood visual impairment is scarce. Objectives: We aimed to assess whether greenness surrounding schools was associated with visual impairment prevalence and visual acuity levels in Chinese schoolchildren and whether the associations might be explained by reduced air pollution. Methods: In September 2013, we recruited 61,995 children and adolescents 6-18 years of age from 94 schools in seven provinces/municipalities in China. Greenness exposure was assessed using the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI) from July to August 2013. Visual impairment was defined as at least one visual acuity level (dimensionless) lower than 4.9 (Snellen 5/6 equivalent). Three-year annual averages of particulate matter (PM) with an aerodynamic diameter of ≤1μm (PM1) and nitrogen dioxide (NO2) at each school were assessed using machine learning methods. We used generalized linear mixed models to estimate the associations between greenness and prevalent visual impairment and visual acuity levels and used mediation analyses to explore the potential mediating role of air pollution. Results: In the adjusted model, an interquartile range increase in NDVI500m was associated with lower odds of prevalent visual impairment [odds ratio (OR)=0.95; 95% confidence interval (CI): 0.93, 0.97]. The same increase in NDVI500m was also associated with 0.012 (95% CI: 0.008, 0.015) and 0.011 (95% CI: 0.007, 0.015) increases in visual acuity levels for left- and right-eye, respectively. Our results also suggested that PM1 and NO2 significantly mediated the association between NDVI500m and visual impairment. Similar effect estimates were observed for SAVI500m, and our estimates were generally robust in several sensitivity analyses. Discussion: These findings suggest higher greenness surrounding schools might reduce the risk of visual impairment, possibly owing in part to lower PM1 and NO2 in vegetated areas. Further longitudinal studies with more precise greenness assessment are warranted to confirm these findings.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego