CFD simulation and optimization on airflow uniformity of material drying room used in steam blanching and hot-air vacuum drying equipment

Dong Wang,Libin Tan,Yuejin Yuan,Yuming Lu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

Airflow velocity uniformity in material drying room used in steam blanching and hot-air vacuum drying equipment is crucial for obtaining a good drying quality of fruits and vegetables. To analyze the airflow velocity uniformity and give the optimization design for improving the airflow uniformity, CFD method is used for the flow field analysis of material drying room and the velocity non-uniformity coefficient is used as the evaluation indicator for the velocity uniformity. Results show that the airflow velocity distribution in the material drying room at the original inlet airflow distribution chamber is relatively uneven and the airflow velocity nonuniformity coefficient in drying area is 34 %. For reducing the airflow velocity non-uniformity, the airflow velocity distribution of three structural modification directions with 12 designs in total are analyzed and compared. The minimum airflow velocity non-uniformity coefficient for adding a spoiler model, reducing the closed end width and adding nozzle baffles are 17.1 %, 30.2 %, 10.4 %, respectively. Through comparison, adding the nozzle baffle with a width of 11 mm at the rear end of each nozzle outlet is considered as the optimal designs to conduct the experimental validation. Experimental validation results shows the the relative error between the simulated value and the measured value is within 10 %, proving that the CFD prediction results is reliable and the research results can give a theoretical reference for the designers to evaluate and optimize the structure of inlet airflow distribution chamber for improving the airflow uniformity in drying area.

Differential Expression Profiles of Alternaria alternate Genes in Response to Carbonyl Sulfide Fumigation

Tao Liu,Li Li,Yuejin Wang,Guoping Zhan,Bo Liu 한국미생물학회 2010 The journal of microbiology Vol.48 No.4

Carbonyl sulfide (COS) is a new fumigant used in phytosanitary treatments. It was developed as a potential alternative to methyl bromide, which is being phased out because of its ozone-depletion properties. To understand the molecular and cellular mechanisms occurring in fungal pathogens in response to COS fumigation, we cloned 510 cDNA fragments of Alternaria alternata (Fr.) Keissler genes that are differentially expressed; these genes were cloned using suppression subtractive hybridization. Changes in the levels of transcripts of 79 fragments were confirmed by microarray analysis and qRT-PCR. Further homology search revealed that they are highly homologous to 41 genes of other fungi, which were related to general metabolism, growth and division, defense, cellular transport, and signal transduction. These results provide an overview of differential expression profiles of A. alternata genes following COS treatment and some new clues about the mechanism of COS fungitoxicity.

A Stability Criterion for Weighting Multiple Model Adaptive Control

Weicun Zhang,Xiaobo Wang,Yuejin Song 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

Based on virtual equivalent system concept and methodology, a criterion on the stability of weighting multiple model adaptive control (MMAC) of linear time-invariant discrete plant is presented. The obtained result indicates that the stability of weighting MMAC depends mainly on the convergence of posterior probability evaluator which represents an identification subsystem in a weighting multiple model adaptive control system. For that a general weighting MMAC with arbitrary controller design strategy and arbitrary algorithm of posterior probability evaluation is considered, we believe that virtual equivalent system concept and methodology could be a potential approach towards a general theory of weighting multiple model adaptive control.

DRA0336, Another OxyR Homolog, Involved in the Antioxidation Mechanisms in Deinococcus radiodurans

Longfei Yin,Liangyan Wang,Huiming Lu,Guangzhi Xu,Hongdan Zhan,Bing Tian,Yuejin Hua,Huan Chen 한국미생물학회 2010 The journal of microbiology Vol.48 No.4

A novel OxyR (DR0615) with one conserved cysteine that senses hydrogen peroxide in Deinococcus radiodurans had been identified in our previous work. Comparative genomics revealed that D. radiodurans possesses another OxyR homolog, OxyR2 (DRA0336). In this study, we constructed the deletion mutant of oxyR2 and the double mutant of both the OxyR homologs to investigate the role of OxyR in response to oxidative stress in D. radiodurans. Deletion of oxyR2 resulted in an obviously increased sensitivity to hydrogen peroxide, and the double mutant for oxyR and oxyR2 was significantly more sensitive than any of the two single mutants. The total catalase activity of the double mutant was lower than that of any of the single mutants, and reactive oxygen species (ROS) accumulated to a greater extent. DNA microarray analysis further suggested that oxyR2 was involved in antioxidation mechanisms. Site-direct mutagenesis and complementation analysis revealed that C228 in OxyR2 was essential. This is the first report of the presence of two OxyR in one organism. These results suggest that D. radiodurans OxyR and OxyR2 function together to protect the cell against oxidative stress.

Light scattering enhanced photoanodes for dye-sensitized solar cells prepared by carbon spheres/TiO_2 nanoparticle composites

Guangtao Yang,Jing Zhang,Peiqing Wang,Qiang Sun,Jun Zheng,Yuejin Zhu 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Incorporating scattering centers in the nanocrystalline photoanode or additional scattering layers on the nanocrystalline photoanode is an effective way to enhance the light harvest efficiency (LHE) of the photoanode and the performance of dye-sensitized solar cells (DSSCs). In this work, mesoporous photoanodes were fabricated based on the composites of anatase TiO_2 nanoparticles and carbon spheres. The holes were left after calcination thus serving as the light scattering centers in the photoanode. The size and the amounts of the holes were adjusted by changing the size (250, 500 and 700 nm) and concentration (5, 10, 15 and 20 wt% of the TiO_2 nanocrystallines) of the carbon spheres in the slurry. The light scattering ability and the dye adsorption of the photoanodes with holes of varied size and contents were investigated. The holes left by calcinating the carbon spheres increased the light scattering of the photoanode. However, the increased light scattering ability offset the dye adsorption ability of the photoanode by high amounts of carbon spheres modification. The performances of the DSSCs are investigated under the simulated sunlight and the incident light (400―780 nm). The DSSC with photoanode made from the slurry with 500 nm and 15 wt% carbon spheres exhibited the opitimized performance (Jsc = 14.8 mA cm^-2, Voc = 0.657 V, FF = 0.703 and η = 7.2%), much better than the DSSCs with photoanode made by the pure TiO_2 nanocrystalline (Jsc = 11.7 mA cm^-2, Voc = 0.645V, FF = 0.699 and η = 5.55%) and other photoanodes, indicating it best balanced the controversy of the enhanced light scattering ability and the decreased dye adsorption. The incident-photo-to-electric conversion efficiency test indicated the highest LHE of the 500 nm and 15 wt% carbon spheres modified photoanode.

Transcriptome analysis reveals molecular strategies of Bactrocera dorsalis (Hendel) larvae in response to anoxia

Deng Yufang,Jiang Fan,Hu Fan,Liang Liang,Wang Yuejin 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.4

Bactrocera dorsalis and its larvae have evolved to cope with the hypoxic environment during their lifetime. In this study, we sequenced the transcriptomes of B. dorsalis under and post anoxia stress. Our data revealed the different biological mechanisms of B. dorsalis in response to anoxia and during recovery from anoxia. The in duction of heat shock proteins (HSPs) might be one of the important mechanisms for B. dorsalis to tolerate anoxia. Furthermore, our data showed B. dorsalis acquires energy through gluconeogenesis rather than glycolysis under anoxia and upregulated its lipid metabolism post anoxia. The up-regulation of the genes involved in the Hippo signaling pathway might also play a role in eliminating damaged cells as a result of anoxia. Furthermore, the HIF system of B. dorsalis did not change in response to anoxia stress in this study. We hypothesized that the HIF system in B. dorsalis might be activated by a specific duration of anoxia.

Abnormal Seedlings Emerged during Embryo Rescue and Its Remedy for Seedless Grape Breeding

Ji, Wei,Li, Zhiqian,Yao, Wenkong,Gong, Peijie,Wang, Yuejin Korean Society of Horticultural Science 2013 원예과학기술지 Vol.31 No.4

The abnormal seedlings, a common physiological anomalies, emerged during embryo rescue severely restricted grape breeding. To enhance the efficiency of the seedless grape breeding by reducing the production of abnormal seedlings in the course of embryo rescue, we investigated the effects of genotype, media type, embryo style, pre-chilling on the deformity rate of the abnormal seedlings during embryo rescue. The abnormal seedlings were firstly classified into seven categories based on their morphology. Our results indicated that the emergence of abnormal seedlings was highly dependent on the female parent genotype. Polyembryony was advantageous to diminish the number of abnormal plantlets and the germination rate of embryo was 100%. We also found that pre-chilling treatment could reduce the number of abnormal plantlets and promote the embryo germination. The abnormal plantlets were reduced significantly by the addition of $ZnSO_4$ $10{\mu}mol{\cdot}L^{-1}$ or mashed-banana $500mg{\cdot}L^{-1}$ to either embryo development or germination media. Transferring the abnormal seedlings onto the suitable fresh media in 4 weeks after embryo germination provided an effective way to transform them into normal seedlings.

Three-Dimensional Hierarchically Ternary Iron Tungsten Nitride Nanosheets with Slight Ratio of Nickel Modulation for Oxygen Evolution Reaction

Xuyang Zhang,Hangjia Shen,Babak Rezaei Moghadam,Siqi Liu,Yuejin Zhu,Jiacheng Wang,Minghui Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Practical application of oxygen evolution reaction (OER) in energy conversion devices, such as water splitting and metal-air batteries, relies on the development of highly efficient and stable electrocatalysts and is still challengeable. Here, Nickel modulated ternary Iron tungsten nitride (Ni-FeWN2) nanosheets are synthesized through a facile hydrothermal growth method and subsequently nitriding process for boosting OER. A potential of 1.57V at the current density of 10 mA/cm2 and Tafel slope (40 mV/dec) are achieved on Ni-FeWN2, much lower than that on Ni-free FeWN2 and commercial IrO2. More importantly, Ni-FeWN2 nanosheets display high stability and electrocatalytic activity toward driving oxygen evolution efficiently in alkaline media.

Abnormal Seedlings Emerged during Embryo Rescue and Its Remedy for Seedless Grape Breeding

Wei Ji,Zhiqian Li,Wenkong Yao,Peijie Gong,Yuejin Wang 한국원예학회 2013 원예과학기술지 Vol.31 No.4

The abnormal seedlings, a common physiological anomalies, emerged during embryo rescue severely restricted grape breeding. To enhance the efficiency of the seedless grape breeding by reducing the production of abnormal seedlings in the course of embryo rescue, we investigated the effects of genotype, media type, embryo style, pre-chilling on the deformity rate of the abnormal seedlings during embryo rescue. The abnormal seedlings were firstly classified into seven categories based on their morphology. Our results indicated that the emergence of abnormal seedlings was highly dependent on the female parent genotype. Polyembryony was advantageous to diminish the number of abnormal plantlets and the germination rate of embryo was 100%. We also found that pre-chilling treatment could reduce the number of abnormal plantlets and promote the embryo germination. The abnormal plantlets were reduced significantly by the addition of ZnSO₄ 10 μmol・L<SUP>-1</SUP> or mashed-banana 500 mg・L<SUP>-1</SUP> to either embryo development or germination media. Transferring the abnormal seedlings onto the suitable fresh media in 4 weeks after embryo germination provided an effective way to transform them into normal seedlings.