Exergy analysis of two-stage steam-water jet injector

Qin Cai,Mingwei Tong,Xiujuan Bai 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.4

Exergy analysis is used as a tool to evaluate exergy losses in the steam-water jet injector so as to improve its overall performance. What this article addresses here is mainly about a parametric study on the injector under various operating conditions, such as different inlet water temperature, inlet steam pressure, pressure ratio, entrainment ratio and flowrate ratio. In addition, the irreversible losses in the component parts of the two-stage injector were analyzed in detail. The results show that the operating parameters have great effects on exergy efficiency of the injector. The average exergy efficiency of the two-stage injector is 21% more than that of the single-stage one. Moreover, calculations based on experimental data indicate that the highest exergy losses due to irreversibility occur in the first-stage mixing chamber. In light of this comparison, the exergy losses occurring in the system are proportional to the exergy efficiency obtained by applying the system.

Survey on the Morbidity of Obesity and Analysis of Related Factors among School Children in Shanghai, China

Cai Mei-Qin,Wang Shao-Mu,Zhang Xiao-Min The Korean Society of Community Nutrition 2004 Journal of community nutrition Vol.6 No.3

Objective : To get a better understanding of obesity and etiological factors of obesity among school children. Methods : We have conducted a questionnaire survey of 4542 (2395male and 2147female) age from 7-15 in Shanghai School District to study their 24h nutrition intakes ; we have asked all our survey participating students to take a physical exam and body mass index measurement to determine the morbidity of obesity. Common statistic method was used in analyzing the data. Results : The result shows an over all morbidity (boys and girls) of $12.3\%$ among the students we have studied. Our research shows that boys have a higher rate of morbidity of obesity $17.1\%$ vs. $7.0\%$ for girls. The morbidity for boys starts under age 10, reaches the peak at age 10 ($24.3\%$), then declines after age 11 ; as for girls the morbidity starts at under age 9, reaches the peak at 9, and then declines after 10. Our study also indicates that the daily nutrition intake of protein, fat and carbohydrate by the students have satisfied Chinese Dietary Reference Intakes (DRIs), while the daily intakes of calcium, iron, zinc, and vitamin C are below the $80\%$ of the DRIs suggested value. For students who are obese, our study shows that their average daily intakes of calories and protein have reached $90\%$ of the suggested value by the RNI while the intakes of calcium, iron, and zinc are far below standards. Furthermore, our research shows that the obese students usually intake more calories, proteins and vitamin $B_1$, but less for iron and calcium compared to the normal students. Some other factors such as the education and occupation of the parents, especially the mother, the family history of obesity and the eating habits are important factors that should be closely watched. Conclusion : The morbidity of obesity among boys is higher than girls. Obesity is closely related to the family history, the diet habits and the life styles.

Preparation and photocatalytic activity of a novel BiOCl/g‑C3N4 thin film prepared via spin coating

Wei‑Qin Cai,De‑Fang Zhang,Feng‑Jun Zhang,Won‑Chun Oh 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.3

Novel BiOCl/g-C3N4 thin film photocatalysts were synthesized via a simple two-step spin coating method. The prepared photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, and ultraviolet–visible spectroscopy. The photocatalytic activity of the thin films for the degradation of rhodamine B under visible light (λ ≥ 400 nm) was investigated. The results showed that the BiOCl/g-C3N4 thin film photocatalysts exhibited significantly improved visible light absorption compared to the pure BiOCl thin film. The BiOCl/g-C3N4 film showed a rhodamine B degradation efficiency of 81.0% under visible light, which is 23.8 times higher than that of the pure BiOCl thin film. This excellent photocatalytic activity of the BiOCl/g-C3N4 film can be attributed to its efficient electron–hole separation due to the presence of g-C3N4.

Photocatalytic CO2 Reduction over g-C3N4 Based Materials

Wei-Qin Cai,Feng-Jun Zhang,Cui Kong,Chun-Mei Kai,Won-Chun Oh 한국재료학회 2020 한국재료학회지 Vol.30 No.11

Reducing CO2 into high value fuels and chemicals is considered a great challenge in the 21st century. Efficiently activating CO2 will lead to an important way to utilize it as a resource. This article reviews the latest progress of g-C3N4 based catalysts for CO2 reduction. The different synthetic methods of g-C3N4 are briefly discussed. Article mainly introduces methods of g-C3N4 shape control, element doping, and use of oxide compounds to modify g-C3N4. Modified g-C3N4 has more reactive sites, which can significantly reduce the probability of photogenerated electron hole recombination and improve the performance of photocatalytic CO2 reduction. Considering the literature, the hydrothermal method is widely used because of its simple equipment and process and easy control of reaction conditions. It is foreseeable that hydrothermal technology will continue to innovate and usher in a new period of development. Finally, the prospect of a future reduction of CO2 by g-C3N4-based catalysts is predicted.

Enhanced photocatalytic hydrogen evolution under visible light using noble metalfree ZnS NPs/Ni@Trimellitic acid porous microsphere heterojunction

Wei-Qin Cai,Feng-Jun Zhang,Ying-Rui Wang,Dong-Cai Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.5

The construction of late-model non-noble metal catalysts with above average performance and stability isthe best choice to implement visible light decomposition of water for hydrogen production and solve the problem ofclean energy. Herein, novel ZnS nanoparticles (ZnS NPs) grown in situ on the surface of porous Ni@Trimellitic acid(Ni-TA) microspheres were successfully synthesized. The structure, optical properties, element composition and othersof ZnS/Ni-TA composites were systematically analyzed by experimental characterization. The experimental resultsshowed that pure ZnS showed very weak photocatalytic performance. However, the photocatalytic performance wasgreatly increased with the addition of Ni-TA. The yield of the best sample (3% ZnS/Ni-TA) reached 1,098 mol/g/h,about 12 times higher than that of ZnS. Among them, Ni-TA not only can be used as the main body of exotic metalnanoparticles, but also the porous channels can prevent the agglomeration of nanoparticles. The enhanced H2 yield ismainly attributed to the resulting tight interface contact and well-matched band position which are conducive to effectivecarrier separation; moreover, the electrons quickly diverted to the exposed edge of Ni-TA for reducing to producehydrogen. The combination of inorganic and new organic semiconductors provides an idea for hydrogen productionunder visible light.

EGCG Blocked Phenylephrin-Induced Hypertrophy in H9C2 Cardiomyocytes, by Activating AMPK-Dependent Pathway

Cai, Yi,Zhao, Li,Qin, Yuan,Wu, Xiao-Qian The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.3

AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.

Optical performance of the Ba₅Al₃F₁₉:Eu²⁺ blue phosphors with high thermal stability

Qin, Lin,Cai, Peiqing,Chen, Cuili,Wang, Jing,Kim, Sun Il,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.738 No.-

<P><B>Abstract</B></P> <P>Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> blue-emitting phosphors were synthesized by the solid state reaction in a reductive atmosphere. The crystal structure of Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphors were characterized by using the X-ray powder diffraction (XRD) measurement. The luminescence properties are investigated systematically based on the crystal structure. Emission and excitation spectra of the Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphor along with the decay curves were characterized. Under the excitation of UV light, the phosphor exhibits a broad band emission around 410 nm ascribed to the allowed 4<I>f</I> <SUP>6</SUP>5<I>d</I>→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition, together with a sharp line at 360 nm corresponding to the forbidden 4<I>f</I> <SUP>7</SUP>(<SUP>6</SUP>P<SUB>7/2</SUB>)→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition of the Eu<SUP>2+</SUP> ions. The temperature dependent emission spectra and decay curves were measured to investigate the origins of the emission and the thermal stabilities of the as-prepared phosphors. The as-prepared Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphors display interesting and stable luminescence properties, which can act as promising blue-emitting phosphor candidates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We developed Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB> fluoride by a simple solid state method. </LI> <LI> The phosphor exhibits a bright broad band emission. </LI> <LI> 4<I>f</I> <SUP>7</SUP>(<SUP>6</SUP>P<SUB>7/2</SUB>)→4<I>f</I> <SUP>7</SUP>(<SUP>8</SUP>S<SUB>7/2</SUB>) transition of the Eu<SUP>2+</SUP> ions can be observed in this system; </LI> <LI> The Ba<SUB>5</SUB>Al<SUB>3</SUB>F<SUB>19</SUB>:Eu<SUP>2+</SUP> phosphor shows excellent thermal stability at high temperature. </LI> </UL> </P>

Preparation, characterization and luminescent properties of red-emitting phosphor: LiLa₂NbO₆ doped with Mn⁴⁺ ions

Qin, Lin,Bi, Shala,Cai, Peiqing,Chen, Cuili,Wang, Jing,Kim, Sun Il,Huang, Yanlin,Seo, Hyo Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.755 No.-

<P><B>Abstract</B></P> <P>Series of Mn<SUP>4+</SUP>-activated LiLa<SUB>2</SUB>NbO<SUB>6</SUB> red emitting phosphors were prepared by the solid state method. The structural and luminescence properties are investigated on the basis of X-ray diffraction (XRD), emission and excitation spectra, and luminescence decay curves. The LiLa<SUB>2</SUB>NbO<SUB>6</SUB>:Mn<SUP>4+</SUP> phosphors can be efficiently excited by near-UV to blue light and exhibit bright red emission at around 712 nm, which can be assigned to the <SUP>2</SUP>E<SUB>g</SUB>→<SUP>4</SUP>A<SUB>2g</SUB> transition of the 3 d<SUP>3</SUP> electrons in [MnO<SUB>6</SUB>] octahedra. Temperature dependent emission spectra and decay curves from 10 to 480 K are analyzed to understand the luminescence mechanism of Mn<SUP>4+</SUP> in LiLa<SUB>2</SUB>NbO<SUB>6</SUB> lattice. Notably, such a novel red emitting phosphor shows special anti-thermal quenching behavior.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We provide a comprehensive study of the luminescence mechanism of the Mn<SUP>4+</SUP> ion. </LI> <LI> Sharp emission lines belong to vibrational modes are observed at low temperature. </LI> <LI> The LiLa<SUB>2</SUB>NbO<SUB>6</SUB>:Mn<SUP>4+</SUP> phosphor shows special anti-thermal stability at low temperature. </LI> </UL> </P>

Electro-thermal model for lithium-ion battery simulations

Cai, Yibin,Che, Yanbo,Li, Hongfeng,Jiang, Mingda,Qin, Peijun The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.10

With the extensive application of lithium batteries and the continuous improvements in battery management systems and other related technologies, the requirements for fast and accurate modeling of lithium batteries are gradually increasing. Temperature plays a vital role in the dynamics and transmission of electrochemical systems. The thermal effect must be considered in battery models. In this paper, a simulation model of a lithium battery with thermal characteristics is established. This thermal model is coupled with a temperature-dependent 2-RC equivalent circuit model to form an electro-thermal model for lithium-ion batteries. The hybrid pulse power characterization test is used to estimate the equivalent circuit parameters. Finally, under NEDC and DST conditions, battery voltage and temperature estimation results of the electro-thermal model are analyzed to verify the correctness and accuracy of the model. The voltage error is within - 0.16~0.20 V under the NEDC condition. Moreover, under the DST condition, the maximum relative error in the electro-thermal model is within 5%.

Electroacupuncture Promotes Neural Proliferation in Hippocampus of Perimenopausal Depression Rats via Wnt/β-Catenin Signaling Pathway

Qin Jing,Lu Ren,Xue Deng,Nan Zhang,Martin Fu,Ge Wang,Xi-Rong Jiang,Shu-Ru Lin,Cai-Rong Ming 사단법인약침학회 2020 Journal of Acupuncture & Meridian Studies Vol.13 No.3

Background and Objective: Perimenopausal depression is caused by the impaired function of the ovarium before menopause and with a series of symptoms. Electroacupuncture (EA) therapy has been demonstrated to improve clinically depression. However, the mechanism underlying its therapeutic activity remains unknown. This study aimed to investigat the effects of EA treatment on the hippocampal neural proliferation through Wnt signaling pathway. Methods: Chronic unpredictable mild stress (CUMS) combined with bilateral ovariectomy (OVX) were used to establish a rat model of perimenopausal depression. The open field test (OFT) and sucrose preference test (SPT) were used to assess depression-like behaviors in rats. ELISAs were used to measure estrogen (E2), luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH) levels in the serum. RT-PCR and Western blot assay were utilized for measuring the mRNA expressions and protein expressions of GSK-3β/β-catenin. Results: Four-week EA treatment at three points including “Shenshu” (BL23), “Baihui” (GV20) and “Sanyinjiao” (SP6) simultaneously ameliorated depression-like behaviors in rats with CUMS and OVX, whereas rescued the decreased serum level of E2 and prevented the increased serum levels of GnRH and LH. EA treatment ameliorated CUMS and OVX-induced alterations of glycogen synthase kinase-3b (GSK-3β) and β-catenin mRNA levels, β-catenin and phosphorylated β-catenin (p-β-catenin) protein levels. Conclusions: The results showed that EA treatment promoted hippocampal neural proliferation in perimenopausal depression rats via activating the Wnt/b-catenin signaling pathway, indicating that EA may represent an efficacious therapy for perimenopausal depression.