Monitoring Enzymes Activity During Vermicomposting of Rural Garbage dosed with Composting Promoter

Chunji Jin,Mengmeng Zhao,Ping Yang 대전대학교 환경문제연구소 2012 환경문제연구소 논문집 Vol.16 No.-

본 연구에서는 물리, 화학, 생물적 처리과정 중 서로 다른 용량의 퇴비가 농촌쓰레기처리공정에서의 수치를 검측하였다. 그 결과, 농촌쓰레기의 5‰ EM 해결시, 지렁이의 생장에 유익했고 34일이 지나면 예비 비료화가 되고, 35일에는 벌레가 자랐다. 5‰ EM 처리 샘플의 C/N비, NH4+-N농도, 활성화 우레아제, 섬유소와 삭카라아제는 다른 그룹보다 낮았지만 NO3-N 농도는 다른 그룹보다 선명하게 높았다. The physical, chemical and biological prarameters during composting process of rural garbage with different dosage of composting promoter were monitored. The results indicated that the addition of 5‰ EM solution to rural garbage was beneficial to growth and reproduction of earthworms after 34 days of pre-composting and 35 days of vermicomposting. C/N ratio, NH4+-N concentration, and the activity of urease, cellulose and sucrase in treatment sample of 5‰EM were lower than that of other groups, while the NO3—N concentration was significantly higher than the other treatment groups.

Development of Multifunctional Folate-Poly(ethylene glycol)-Chitosan-Coated Fe3O4 Nanoparticles for Biomedical Applications

Shuifan Zhou,Zhenqing Hou,Yang Li,Fei Cui,Mengmeng Jia,Xiangrui Yang,Yange Wang,Liya Xie,Qiqing Zhang 한국고분자학회 2014 Macromolecular Research Vol.22 No.1

The efficacy of magnetic nanoparticles (MNPs) for biomedical applications depends on the specic targetingcapacity, blood circulation time and magnetic susceptibility. Functionalized chitosan-coated Fe3O4 nanoparticles(CS-coated Fe3O4 NPs) were synthesized by a non-solvent-aided coacervation procedure followed by a chemicalcrosslinking procedure. The surfaces of CS-coated Fe3O4 NPs were successfully functionalized with folate-poly(ethyleneglycol)-COOH (FA-PEG) to obtain novel FA-PEG-CS-coated Fe3O4 NPs endowed with long blood circulationand specic targeting capacity. The as-synthesized NPs were characterized by dynamic light scattering, transmissionelectron microscope, X-ray diffraction, thermal gravimetric analysis, vibration sample magnetometer, Fourier transforminfrared spectroscopy, and confocal laser scanning microscopy. As a result, the novel FA-PEG-CS-coated Fe3O4 NPsshowed excellent biocompatibility, magnetic properties, good dispersibility, and proper hydrodynamic sizes in an aqueousmedium. The specific targeting capacity of the as-synthesized NPs to cancer cells was also investigated. It wasobserved that the uptake of the FA-PEG-CS-coated Fe3O4 NPs by HeLa cells was significantly enhanced comparedto the CS-coated Fe3O4 NPs and mPEG-CS-coated Fe3O4 NPs. These results clearly indicate that our novel FA-PEGCS-coated Fe3O4 NPs with remarkable specific targeting capacity, long blood circulation, and superparamagnetismhold great promise for biomedical applications, including targeted drug delivery and hyperthermia therapy.

Distributed Topology Control With Lifetime Extension Based on Non-Cooperative Game for Wireless Sensor Networks

Mengmeng Xu,Qinghai Yang,Kyung Sup Kwak IEEE 2016 IEEE SENSORS JOURNAL Vol.16 No.9

<P>In a large and complex distributed sensor network, the individual sensor directly communicates only with its neighboring sensors. Despite being restricted to such local communications, the network itself should be self-organizing to maintain certain desirable properties, such as network connectivity and lifetime maximization. Topology control is a technique to determine the optimal transmit parameters for each sensor, such that the network topology has the best possible network performance. In this paper, we investigate a dynamic topology control scheme to improve the network lifetime for wireless sensor networks in the presence of selfish sensors. A non-cooperative game aided topology control approach is developed for designing energy-efficient and energy balanced network topologies dynamically. Each sensor in the topology control game tries to minimize its unwillingness for constructing a connected network according to its residual energy and transmit power. We prove the existence of Nash equilibrium (NE) and demonstrate that the NE is Pareto optimal as well. Specifically, a fully distributed algorithm-topology control with lifetime extension (TCLE)-is proposed to construct dynamic network topologies. The topologies derived by TCLE algorithm can improve the network lifetime significantly as compared with existing algorithms. Simulations demonstrate the efficiency of our TCLE algorithm.</P>

Assessment of Myocardial Bridge by Cardiac CT: Intracoronary Transluminal Attenuation Gradient Derived from Diastolic Phase Predicts Systolic Compression

Mengmeng Yu,Yang Zhang,Yuehua Li,Minghua Li,Wenbin Li,Jiayin Zhang 대한영상의학회 2017 Korean Journal of Radiology Vol.18 No.4

Objective: To study the predictive value of transluminal attenuation gradient (TAG) derived from diastolic phase of coronary computed tomography angiography (CCTA) for identifying systolic compression of myocardial bridge (MB). Materials and Methods: Consecutive patients diagnosed with MB based on CCTA findings and without obstructive coronary artery disease were retrospectively enrolled. In total, 143 patients with 144 MBs were included in the study. Patients were classified into three groups: without systolic compression, with systolic compression < 50%, and with systolic compression ≥ 50%. TAG was defined as the linear regression coefficient between intraluminal attenuation in Hounsfield units (HU) and length from the vessel ostium. Other indices such as the length and depth of the MB were also recorded. Results: TAG was the lowest in MB patients with systolic compression ≥ 50% (-19.9 ± 8.7 HU/10 mm). Receiver operating characteristic curve analysis was performed to determine the optimal cutoff values for identifying systolic compression ≥ 50%. The result indicated an optimal cutoff value of TAG as -18.8 HU/10 mm (area under curve = 0.778, p < 0.001), which yielded higher sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (54.1, 80.5, 72.8, and 75.0%, respectively). In addition, the TAG of MB with diastolic compression was significantly lower than the TAG of MB without diastolic compression (-21.4 ± 4.8 HU/10 mm vs. -12.7 ± 8 HU/10 mm, p < 0.001). Conclusion: TAG was a better predictor of MB with systolic compression ≥ 50%, compared to the length or depth of the MB. The TAG of MB with persistent diastolic compression was significantly lower than the TAG without diastolic compression.

Energy-Connectivity Tradeoff through Topology Control in Wireless Ad Hoc Networks

Mengmeng Xu,Qinghai Yang,곽경섭 한국전자통신연구원 2017 ETRI Journal Vol.39 No.1

In this study, we investigate topology control as a means of obtaining the best possible compromise between the conflicting requirements of reducing energy consumption and improving network connectivity. A topology design algorithm capable of producing network topologies that minimize energy consumption under a minimum-connectivity constraint is presented. To this end, we define a new topology metric, called connectivity efficiency, which is a function of both algebraic connectivity and the transmit power level. Based on this metric, links that require a high transmit power but only contribute to a small fraction of the network connectivity are chosen to be removed. A connectivity-efficiency-based topology control (CETC) algorithm then assigns a transmit power level to each node. The network topology derived by the proposed CETC heuristic algorithm is shown to attain a better tradeoff between energy consumption and network connectivity than existing algorithms. Simulation results demonstrate the efficiency of the CECT algorithm.

A Trajectory Data Clustering Method Based On Dynamic Grid Density

Junhuai Li,Mengmeng Yang,Na Liu,Zhixiao Wang,Lei Yu 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.2

Monitoring Enzymes Activity During Vermicomposting of Rural Garbage dosed with Composting Promoter

Chunji Jin,Mengmeng Zhao,Ping Yang 대전대학교 환경문제연구소 2012 환경문제연구소 논문집 Vol.16 No.-

The physical, chemical and biological prarameters during composting process of rural garbage with different dosage of composting promoter were monitored. The results indicated that the addition of 5‰ EM solution to rural garbage was beneficial to growth and reproduction of earthworms after 34 days of pre-composting and 35 days of vermicomposting. C/N ratio, NH₄+-N concentration, and the activity of urease, cellulose and sucrase in treatment sample of 5‰EM were lower than that of other groups, while the NO₃—N concentration was significantly higher than the other treatment groups. 본 연구에서는 물리, 화학, 생물적 처리과정 중 서로 다른 용량의 퇴비가 농촌쓰레기처리공정에서의 수치를 검측하였다. 그 결과, 농촌쓰레기의 5‰ EM 해결시, 지렁이의 생장에 유익했고 34일이 지나면 예비 비료화가 되고, 35일에는 벌레가 자랐다. 5‰ EM 처리 샘플의 C/N비, NH₄+-N농도, 활성화 우레아제, 섬유소와 삭카라아제는 다른 그룹보다 낮았지만 NO₃-N 농도는 다른 그룹보다 선명하게 높았다.

Patterning-Induced Ferromagnetism of Fe₃GeTe₂ van der Waals Materials beyond Room Temperature

Li, Qian,Yang, Mengmeng,Gong, Cheng,Chopdekar, Rajesh V.,N’Diaye, Alpha T.,Turner, John,Chen, Gong,Scholl, Andreas,Shafer, Padraic,Arenholz, Elke,Schmid, Andreas K.,Wang, Sheng,Liu, Kai,Gao, Nan,Admas American Chemical Society 2018 NANO LETTERS Vol.18 No.9

<P>Magnetic van der Waals (vdW) materials have emerged as promising candidates for spintronics applications, especially after the recent discovery of intrinsic ferromagnetism in monolayer vdW materials. There has been a critical need for tunable ferromagnetic vdW materials beyond room temperature. Here, we report a real-space imaging study of itinerant ferromagnet Fe<SUB>3</SUB>GeTe<SUB>2</SUB> and the enhancement of its Curie temperature well above ambient temperature. We find that the magnetic long-range order in Fe<SUB>3</SUB>GeTe<SUB>2</SUB> is characterized by an unconventional out-of-plane stripe-domain phase. In Fe<SUB>3</SUB>GeTe<SUB>2</SUB> microstructures patterned by a focused ion beam, the out-of-plane stripe domain phase undergoes a surprising transition at 230 K to an in-plane vortex phase that persists beyond room temperature. The discovery of tunable ferromagnetism in Fe<SUB>3</SUB>GeTe<SUB>2</SUB> materials opens up vast opportunities for utilizing vdW magnets in room-temperature spintronics devices.</P> [FIG OMISSION]</BR>

Study on Static and Dynamic Reliability of Main Girder of Cable-stayed Bridge Based on Subset Simulation Method

Zhenhao Zhang,Mengmeng Tao,Fuming Wang,Yi Yang,Lu Ke 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

For failure probability analysis of complex structures, the Monte Carlo method (MC) needs alarge number of samples and it is more inefficient in the case of small failure probability. Basedon the Subset Simulation (SS) and Subset Simulation Significant Sampling (SSIS), this paperanalyzes the static and dynamic reliability of main girder of cable-stayed bridge and realizesthe efficient solution of the failure probability of complex cable-stayed bridge. According toSS, MC sampling is performed on random variables. Finally, the critical values of intermediatefailure events are solved and automatically stratified, and then the failure probability of eachfailure mode is obtained by counting the number of samples in the failure domain. Accordingto SSIS method, SS method is optimized by introducing important sampling density function,which can make the sample points to fall in the structural failure areas as many as possible. The failure probability of main girder of cable-stayed bridge can be calculated more efficiently. Meanwhile, ANSYS-PDS template technique is used to perform the reliability and sensitivityanalysis of main girder of cable-stayed bridge. The failure probabilities obtained are very closeto the results of SS. The example analysis shows that for the reliability analysis of cable-stayedbridges, the sample size of SS and SSIS is 0.3% of MC, and the maximum relative difference isless than 3%. In addition the main beam section bending moment and wind speed have thegreatest impact on the reliability of the main beam of cable-stayed bridges.

Modified graphite paper treated by anionic intercalation for manganese removal via electrochemical deposition in water treatment

Tianfei Chu,Mengmeng Cheng,Shifeng Hou,Yanzhao Yang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Effective removal of excess manganese ions (Mn2+) from water is urgently needed to maintain humanhealth and ecological balance. To date, electrochemical deposition (ED) techniques have been widelyused for their simplicity and flexibility, while the active surface area and reliability of electrodes are stillmajor issues. Herein, modified graphite papers (MGP) fabricated by the anionic intercalation methodwere used as the working electrode to remove Mn2+ from wastewater via the electrochemical depositionmethod. The results showed that the highest removal of Mn2+ by MGP-E was achieved when the voltagewas 1.0 V, the deposition time was 6 h, and the pH value of the wastewater was 3.0. Under the aboveparameters, the removal rate of Mn2+ in simulated wastewater can reach over 99.73 %, while the removalrates in industrial wastewater and groundwater can reach 96.20 % and 99.27 %, respectively, which canmeet the standard of water treatment. The related tests confirmed that the deposition process had excellentcycling stability and low energy consumption. This study may provide an economical, sustainableand efficient electrode material for Mn2+ removal from industrial wastewater and groundwater via electrochemicaldeposition technology.