Tensile strength of wood polylactic acid composite: A meta-analysis

Lei Lv,Zhenhua Guo,Hongdi Wang 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.5

It is worth mentioning that polylactic acid (PLA) is extracted from plants and it can be considered a renewable resource. Thesustainable development of resources can be achieved by turning PLA and wood production into wood plastic composite(WPC). In this study, the mechanical properties of WPC were compared in a meta-analysis that focused on WPC made withPLA because the tensile strength (TS) of WPC compared with PLA was unclear. We assessed changes in the mechanicalproperties of PLA and wood used to make WPC by identifying 1919 peer-reviewed manuscripts, of which 15 articles wereincluded in this analysis. We found that adding 10%–50% wood flour reduced the TS, breaking elongation, and impactstrength of WPC. This did not affect the bending modulus. More work is required to solve the compatibility issues betweenwood fiber and plastics as well as to better understand the degradability of PLA-WPC. Additionally, the cost reduction forWPC synthesis must be addressed.

A regression for estimating metabolizable glucose in diets of weaned piglets for optimal growth performance

Lv, Liangkang,Feng, Zhi,Zhang, Dandan,Lei, Long,Zhang, Hui,Liu, Zhengya,Ren, Ying,Zhao, Shengjun Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.10

Objective: Two experiments were conducted to provide a new approach for evaluating feed nutritional value by metabolizable glucose (MG) in piglet diets with different levels of starch and crude fiber. In Exp 1, a regression equation for MG was generated. In Exp 2, the equation was verified, and the optimal growth performance of piglets under appropriate MG levels was tested. Methods: In Exp 1, 20 weaned piglets (7.74±0.81 kg body weight [BW]) were randomly assigned to 1 of 4 treatments, including the basal diet containing different levels of MG (starch, 25.80%, 31.67%, 45.71%, 49.36%; crude fiber, 1.23%, 1.35%, 1.80%, 1.51%). The piglets were implanted with an ileal fistula, cannulation of the carotid artery, portal vein, and mesenteric artery. The chyme from the ileum fistula and blood samples were collected. In Exp 2, 30 weaned piglets (8.96±0.50 kg BW) were randomly assigned to 1 of 5 treatments, including the experimental diets with different levels of MG (37.6, 132.5, 300.0, 354.3, and 412.5 g/kg). The piglets' BW, and feed consumption were recorded to calculate growth performance during the 28-d experiment. Results: In Exp 1, the MG levels in 4 diets were 239.62, 280.68, 400.79, and 454.35 g/kg. The regression equation for the MG levels and dietary nutrients was: Y (MG) = 12.13×X₁ (starch)+23.18×X₂ (crude fiber)-196.44 (R² = 0.9989, p = 0.033). In Exp 2, treatments with 132.5 and 300.0 g/kg MG significantly (p<0.05) increased average daily gain and feed conversion efficiency of weaned piglets, increased digestibility of crude fat, and had no effect on digestibility of crude protein compared to 300.0 to 412.5 g/kg MG. Conclusion: The pig model combining the ileum fistula and cannulation of blood vessels was successfully used to determine the dietary MG levels. The recommended MG level in weaned pig diets is 132.5 to 300.0 g/kg.

한반도 식생의 녹색화에 대한 시계열적 분석

Lv, Guan Ting,ZHUYONGYAN,Liu, Wei Qi,Huang, Xiao,Li, Cheng Lei,Cui, Gui Shan 한국기후변화학회 2019 한국기후변화학회지 Vol.10 No.4

The vegetation is feedback on environmental change due to global warming. Also, the growth status of vegetation and the coverage area of vegetation are greatly affected by the environmental changes. The quantitative change of vegetation growth status is the primary task of vegetation response to environmental changes. In this study, the Global Inventory Modeling and Mapping Studies (GIMMS) based Normalized Difference Vegetation Index (NDVI) and CRU climate data are used to analyze the spatio‐temporal characteristics of vegetation greening evolution and its response to climate change from 1982 to 2015 in the Korean Peninsula by applying the partial correlation and trend analysis. The results show that the average NDVI value of the Korean Peninsula in the period 1982‐2015 was 0.68, among which the average NDVI in North Korea and South Korea was 0.69 and 0.67, respectively. The NDVI of the Korean Peninsula between 1982 and 2015 increased by 0.6x10‐3 year‐1. The increasing trend prior to and after 1998 was 2.5×10‐3 year‐1 and 0.9×10‐3 year‐1, respectively. During the 1982‐2015 years, the NDVI of DPRK and South Korea have grown mainly with the trend of 0.2×10‐3 year‐1 and 1.1×10‐3 year‐1, respectively. According to the analysis of NDVI and climatic factors, the distribution of NDVI in the three‐time series of Korean Peninsula is consistent in spatial distribution. According to the results of partial correlation analysis of climate factor and NDVI distribution in Korean Peninsula, the region has significant partial correlation with temperature change. The climate factor of temperature is the main driver of NDVI change, which plays a key role in controlling NDVI change accumulation.

Effects of three main sugars in cane molasses on the production of butyric acid with Clostridium tyrobutyricum

Lei Huang,Zhinan Xu,Yijuan Xiang,Jin Cai,Ling Jiang,Zhengbing Lv,Yaozhou Zhang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.12

The effects of three main sugars in cane molasses were investigated systematically to prepare a cost-effective medium for butyric acid bioproduction. Additionally, 30 g/L corn steep liquor was screened out as the suitable nitrogen source. In the batch fermentation of free cells, when 60 g/L glucose was the only carbon source, 21.28 g/L butyric acid was achieved after 30 h cultivation. Similar product concentration, productivity and yield were obtained when 60 g/L fructose was applied. The utilization of sucrose would bring about lower productivity (0.29 g/L·h) and product concentration (18.15 g/L), but the yield of butyric acid/sucrose (0.34 g/g) is almost the same as that from glucose or fructose (0.35 g/g). Finally, the sugar mixture (15 g/L glucose, 20 g/L fructose and 35 g/L sucrose) was employed to produce butyric acid in a fibrous-bed bioreactor (FBB), and 40.11 g/L butyric acid was produced with one simple fed-batch strategy.

Age quadratically affects intestinal calcium and phosphorus transporter gene expression in broiler chickens

Lv, Xianliang,Hao, Junfang,Wu, Lihua,Liu, Mengyuan,He, Lei,Qiao, Yingying,Cui, Yanyan,Wang, Guan,Zhang, Chunmei,Qu, Hongxia,Han, Jincheng Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.12

Objective: This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. Methods: A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Results: Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. Conclusion: These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.

Bonding Behavior of TRC-Confined Concrete and Reinforcement under Chloride Erosion Environment

Lei Jing,Shiping Yin,Henglin Lv 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.3

The improved effect of the bonding behavior of concrete and reinforcement is a critical indicator for estimating the validity of strengthening measures. The bonding behavior of unconfined or textile reinforced concrete (TRC)-confined concrete and a plain or deformed reinforcement was comparatively analyzed via the pull-out tests, and the influence of chloride wet-dry cycles also was considered on the bonding behavior. Moreover, the bonding behavior was further revealed from the view of energy. The study results indicated that the bonding failure of specimens with a deformed reinforcement was changed after TRC confinement, showing a certain ductile failure characteristic, and the integrity of the confined specimens was ensured at failure. The impact of chloride attack on the bonding behavior of concrete and a plain or deformed reinforcement was different under the unconfined or TRC-confined condition. The deterioration mechanism of the bonding behavior needs to be further investigated when the reinforcement is corroded seriously. The results from the energy analysis are consistent with the pull-out test results.

Phenolic features and anthocyanin profiles in winemaking pomace and fresh berries of grapes with different pedigrees

Lei Zhu,Xin Wu,Xixi Hu,Xinyue Li,Shanshan Lv,Chuan Zhan,Yunhua Chen,Changyuan Wang,Jingyu Xu 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.2

The total contents and antioxidant activities of phenolic compounds as well as anthocyanin profiles were analyzed and compared in fresh berries and fermented pomace of three grape cultivars with different pedigrees. The phenolic contents and antioxidant activities decreased significantly in skins (p < 0.05), while relatively large amounts of them were retained in seeds after fermentative maceration. Fermentative maceration also had a significant impact on the anthocyanin compositions. The proportions of anthocyanins with more stable structures, such as malvidin derivatives, methylated, diglucosides and nonacylated anthocyanins, increased significantly in the pomace skins (p < 0.05). There were obvious differences in phenolic features and anthocyanin profiles among the three cultivars. ‘NW196’, a wine hybrid of Vitis vinifera and V. quinquangularis, was characterized by the highest total anthocyanin contents and degree of diglucosylation. The results obtained in this study could contribute to the primary data for the development and utilization of winemaking pomace, especially from local non-Vitis vinifera grapes.

Methylation-associated silencing of BASP1 contributes to leukemogenesis in t(8;21) acute myeloid leukemia

Lei Zhou,Lin Fu,Na Lv,Jing Liu,Yan Li,Xiaosu Chen,Qingyu Xu,Guofeng Chen,Baoxu Pang,Lili Wang,Yonghui Li,Xiaodong Zhang,Li Yu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

The AML1-ETO fusion protein (A/E), which results from the t(8;21) translocation, is considered to be a leukemiainitiating event. Identifying the mechanisms underlying the oncogenic activity of A/E remains a major challenge. In this study, we identified a specific down-regulation of brain acid-soluble protein 1 (BASP1) in t(8;21) acute myeloid leukemia (AML). A/E recognized AML1-binding sites and recruited DNA methyltransferase 3a (DNMT3a) to the BASP1 promoter sequence, which triggered DNA methylation-mediated silencing of BASP1. Ectopic expression of BASP1 inhibited proliferation and the colony-forming ability of A/E-positive AML cell lines and led to apoptosis and cell cycle arrest. The DNMT inhibitor decitabine up-regulated the expression of BASP1 in A/E-positive AML cell lines. In conclusion, our data suggest that BASP1 silencing via promoter methylation may be involved in A/E-mediated leukemogenesis and that BASP1 targeting may be an actionable therapeutic strategy in t(8;21) AML.

An Experimental and Numerical Study of Corona in a Cage with Sandy and Dusty Flow in High Altitude Area

Lv, Yukun,Ge, Zekun,Liu, Yunpeng,Zhu, Lei,Wei, Shaoke The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

In order to study the effect of the high-altitude and dusty weather in northwest of China on the corona characteristics of transmission lines, a corona caged based experimental system with sandy and dusty flow condition is numerically investigated and designed. This system overcomes the difficulties caused by harsh environment and offers easy usage for off-site tests. The design parameters are mainly determined by the characteristics of strong sandstorm in northwest region and test requirements. By the comparison of numerical simulation of the particle diffusion in four programs with rectangular or circular air-duct, a practical technology, which introduces swirl to control the particle diffusion length, is obtained. Accordingly, the structure of round air-duct with swirl elbow in inlet and outlet of high level segment is selected as final program. Systems of control and measurement are designed at the same time. Field tuning results show that the test system could ensure the range of sandy and dusty coverage. The wind speed, sandy and dusty concentration could be controlled and meet the requirements of accuracy. The experimental system has many features, such as simple structure, easy to be assembled, disassembled, transported and operated, small space occupied.

Pattern Recognition of Partial Discharge in Power Transformer Based on InfoGAN and CNN

Lv Fangcheng,Liu Guilin,Wang Qiang,Lu Xiuquan,Lei Shengfeng,Wang Shenghui,Ma Kang 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

As an important equipment in the power system, it has a significant meaning in scientifically diagnosing the insulation state of oil-immersed power transformers. At present, the pattern recognition of partial discharge (PD) in a transformer has the problem of the insufficient generalization ability of the classifier due to scarcity and imbalance of samples, resulting in low recognition accuracy. To solve this problem, this paper proposes a pattern recognition of the PD method based on information maximizing generative adversarial nets (InfoGAN) and convolutional neural networks. In this method, phase-resolved partial discharge (PRPD) maps, constructed from pulse current waveforms, are chosen as the training samples. First, the InfoGAN is trained to generate new samples which expanded the original sample database, then various classifiers are trained by using the expanded sample database to realize the pattern recognition. Results of the test show that the proposed method can generate new highly similar samples more stable than other data enhancement methods, and effectively enrich the data diversity. In addition, the classifier trained by the expanded sample database has better generalization ability and is applicable to different classifiers, while residual network 18 has the highest recognition rate of 99.0%. This method can effectively balance and expand PRPD samples, and improve the recognition accuracy of the classifier to a certain extent. It has a good application prospect in PD diagnosis engineering.