Quantifying herbicide dose-response and resistance in <i>Echinochloa</i> spp. by measuring root length in growth pouches

Zhang, C. J.,Lim, S. H.,Kim, J. W.,Song, J. S.,Yook, M. J.,Nah, G.,Valverde, B. E.,Kim, D. S. Canadian Science Publishing 2015 Canadian journal of plant science. Revue canadienn Vol.95 No.6

<P> Zhang, C. J., Lim, S. H., Kim, J. W., Song, J. S., Yook, M. J., Nah, G., Valverde, N. E. and Kim, D. S. 2015. Quantifying herbicide dose-response and resistance in Echinochloa spp. by measuring root length in growth pouches. Can. J. Plant Sci. 95: 1181-1192. The aim of the presented study was to develop a bioassay for rapid diagnosis of herbicide dose-response and resistance in Echinochloa. Pre-germinated seeds of Echinochloa spp. were incubated in growth pouches (18 cm×16.5 cm) containing herbicide solutions in a range of concentrations. Shoot and root lengths were measured after 6 d of incubation. Dose-responses estimated by measuring root lengths in the growth pouches were well-described by the log-logistic dose-response model and similar to those estimated by a whole-plant assay. Accurate dose-response curves were successfully generated for several herbicides with different modes of action, suggesting that the growth pouch method can be used for herbicide bioassays. The suitability of the growth pouch method for rapid diagnosis of acetyl coenzyme-A carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor resistance in Echinochloa spp. was also tested. For cyhalofop-butyl, resistant and susceptible biotypes were discriminated at 180-300 mg a.i. L<SUP>−1</SUP> and 80-120 mg a.i. L<SUP>−1</SUP> for barnyardgrass (E. crus-galli) and late watergrass (E. oryzicola), respectively. For penoxsulam, the discriminatory dosage was 350-500 mg a.i. L<SUP>−1</SUP> for barnyardgrass and 650-1000 mg a.i. L<SUP>−1</SUP> for late watergrass. The method was further used to identify late watergrass biotypes resistant and susceptible to two other ALS inhibitors, azimsulfuron and bispyribac-sodium. Our results show that the growth pouch method can be reliably used in herbicide dose-response studies and to diagnose herbicide resistance in Echinochloa spp., with significant time and cost savings compared with conventional whole-plant assays. </P>

J-Sim: a simulation and emulation environment for wireless sensor networks

Sobeih, A.,Hou, J.C.,Lu-Chuan Kung,Ning Li,Honghai Zhang,Wei-Peng Chen,Hung-Ying Tyan,Hyuk Lim IEEE 2006 IEEE wireless communications Vol.13 No.4

<P>Wireless sensor networks have gained considerable attention in the past few years. They have found application domains in battlefield communication, homeland security, pollution sensing, and traffic monitoring. As such, there has been an increasing need to define and develop simulation frameworks for carrying out high-fidelity WSN simulation. In this article we present a modeling, simulation, and emulation framework for WSNs in J-Sim - an open source, component-based compositional network simulation environment developed entirely in Java. This framework is built on the autonomous component architecture and extensible internetworking framework of J-Sim, and provides an object-oriented definition of target, sensor, and sink nodes, sensor and wireless communication channels, and physical media such as seismic channels, mobility models, and power models (both energy-producing and energy-consuming components). Application-specific models can be defined by subclassing classes in the simulation framework and customizing their behaviors. We also include in J-Sim a set of classes and mechanisms to realize network emulation. We demonstrate the use of the proposed WSN simulation framework by implementing several well-known localization, geographic routing, and directed diffusion protocols, and perform performance comparisons (in terms of the execution time incurred and memory used) in simulating WSN scenarios in J-Sim and ns-2. The simulation study indicates the WSN framework in J-Sim is much more scalable than ns-2 (especially in memory usage). We also demonstrate the use of the WSN framework in carrying out real-life full-fledged Future Combat System (FCS) simulation and emulation</P>

Logarithmically completely monotonic functions and Gurland's ratio for the gamma function

Y. J. Wei,S. L. Zhang,C. P. Chen 장전수학회 2007 Advanced Studies in Contemporary Mathematics Vol.15 No.2

Two logarithmically completely monotonic functions involving gamma function are proved. As an application, bounds for the ratio T(x;y) = ( x)(y)= 2((x+y)=2) is established and the corresponding result by J. D. keckic and P. M.Vasic is refined.

Tailoring the defects and carrier density for beyond 10% efficient CZTSe thin film solar cells

Li, J.,Kim, S.,Nam, D.,Liu, X.,Kim, J.,Cheong, H.,Liu, W.,Li, H.,Sun, Y.,Zhang, Y. North-Holland ; Elsevier Science Ltd 2017 Solar energy materials and solar cells Vol.159 No.-

The defects states and carrier density of CZTSe absorber layers are two of the crucial factors that decide the photovoltaic performance of CZTSe thin film solar cells. Fine tailoring the defects and carrier density is a key to push the power conversion efficiency of CZTSe solar cells to a more competitive level. In this work, the phase properties, defect states, and carrier density of CZTSe thin film are well controlled by fine tuning the ratio of Zn/Sn in the range from 0.75 to 1.27. Capacity-Voltage measurements and Admittance Spectroscopy are used to characterize the carrier density, depletion region width, and defect states of the CZTSe solar cells. The results indicate that the defects states and carrier density of CZTSe layer are very sensitive to the ratio of Zn/Sn. Combining experimental results and numerical simulation, the statistic regularities of the photovoltaic parameters of the CZTSe solar cells with different ratios of Zn/Sn is well explained. The increase of V<SUB>OC</SUB> of CZTSe solar cells with the ratio of Zn/Sn is related to both the increased carrier density and the decreased deep level defects states. The decline of J<SUB>SC</SUB> of the Zn-rich solar cells is caused by both the shrunken depletion region width and a large barrier caused by ZnSe phase. This barrier is the cause for a low fill factor in the Zn-rich solar cells. Overall, the CZTSe solar cells with a stoichiometric ratio of Zn/Sn=1.02 have favorable defects property and carrier density, thus resulting in the highest photovoltaic efficiency of 10.21%.

Relativistic jet activity from the tidal disruption of a star by a massive black hole

Burrows, D. N.,Kennea, J. A.,Ghisellini, G.,Mangano, V.,Zhang, B.,Page, K. L.,Eracleous, M.,Romano, P.,Sakamoto, T.,Falcone, A. D.,Osborne, J. P.,Campana, S.,Beardmore, A. P.,Breeveld, A. A.,Chester, Nature Publishing Group, a division of Macmillan P 2011 Nature Vol.476 No.7361

Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.

Ultimate strength behavior of steel-concrete-steel sandwich beams with ultra-lightweight cement composite, Part 2: Finite element analysis

Jia-Bao Yan,J.Y. Richard Liew,Min-Hong Zhang 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.4

Ultra-lightweight cement composite (ULCC) with a compressive strength of 60 MPa and density of 1,450 kg/㎥ has been developed and used in the steel-concrete-steel (SCS) sandwich structures. This paper investigates the structural performances of SCS sandwich composite beams with ULCC as filled material. Overlapped headed shear studs were used to provide shear and tensile bond between the face plate and the lightweight core. Three-dimensional nonlinear finite element (FE) model was developed for the ultimate strength analysis of such SCS sandwich composite beams. The accuracy of the FE analysis was established by comparing the predicted results with the quasi-static tests on the SCS sandwich beams. The FE model was also applied to the nonlinear analysis on curved SCS sandwich beam and shells and the SCS sandwich beams with J-hook connectors and different concrete core including ULCC, lightweight concrete (LWC) and normal weight concrete (NWC). Validations were also carried out to check the accuracy of the FE analysis on the SCS sandwich beams with J-hook connectors and curved SCS sandwich structure. Finally, recommended FE analysis procedures were given.

Leakage Currents of a Fast Switching Thyristor Made by Proton Irradiation Method

E.D. Kim,C.L. Zhang,S.C. Kim,N.K. Kim,J.Z. Zhu,B.F. Yang 전력전자학회 2004 ICPE(ISPE)논문집 Vol.- No.-

A thyristor with a VRRM of 1,600V was made with 200μm of N-base width from 60Ω·cm NTD-Si wafer and the proton irradiation was employed for improving its switching performance. This study showed that 4.7MeV-proton irradiation gives a narrow distribution of induced defects in the middle of N-drift region with its width of 10μm, which resulted in a superior trade-off relation between its static and dynamic characteristics. It was found that 3.7MeV and 5.9MeV protons remarkably increased the forward leakage current IDRM and the reverse leakage current IRRM, respectively. The increased IDRM and IRRM are attributed to the induced defects in the depletion layers of thyristor junctions J2 and J1, respectively.

Experimental Study of the Runaway Current in the J-TEXT Tokamak

Y. H. Luo,Z. Y. Chen,X. Q. Zhang,D. W. Huang,W. Jin,Y. H. Huang,Y. Tang,J. C. Li,R. H. Tong,W. Yan,G. Zhuang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.3

Major plasma disruptions in tokamaks often generate runaway currents, which contain electronswith energies of several tens of megaelectron-volts (MeV). These currents can cause substantialdamage when control is lost and the current hits the limiters or the vessel wall. The interactionbetween the runaway electrons and the impurities inside the plasma results in soft X-ray emission,which can provide detailed information about the runaway generation process and the confinementof runaway electrons. A vertical soft X-ray array at the top of Joint Texas Experimental Tokamak(J-TEXT) was used to study the runaway beams resulting from major disruptions. Runawayelectron production and confinement of runaway current were observed by using soft X-ray images.

Sensitivity of surface characteristics on the simulation of wind-blown-dust source in North America

Park, S.H.,Gong, S.L.,Gong, W.,Makar, P.A.,Moran, M.D.,Stroud, C.A.,Zhang, J. Pergamon Press ; Elsevier [distribution] 2009 Atmospheric environment Vol.43 No.19

Recently, a wind-blown-dust-emission module has been built based on a state-of-the-art wind erosion theory and evaluated in a regional air-quality model to simulate a North American dust storm episode in April 2001 (see Park, S.H., Gong, S.L., Zhao, T.L., Vet, R.J., Bouchet, V.S., Gong, W., Makar, P.A., Moran, M.D., Stroud, C., Zhang, J. 2007. Simulation of entrainment and transport of dust particles within North America in April 2001 (''Red Dust episode''). J. Geophys. Res. 112, D20209, doi:10.1029/2007JD008443). A satisfactorily detailed assessment of that module, however, was not possible because of a lack of information on some module inputs, especially soil moisture content. In this paper, the wind-blown-dust emission was evaluated for two additional dust storms using improved soil moisture inputs. The surface characteristics of the wind-blown-dust source areas in southwestern North America were also investigated, focusing on their implications for wind-blown-dust emissions. The improved soil moisture inputs enabled the sensitivity of other important surface characteristics, the soil grain size distribution and the land-cover, to dust emission to be investigated with more confidence. Simulations of the two 2003 dust storm episodes suggested that wind-blown-dust emissions from the desert areas in southwestern North America are dominated by emissions from dry playas covered with accumulated alluvial deposits whose particle size is much smaller than usual desert sands. As well, the source areas in the northwestern Texas region were indicated to be not desert but rather agricultural lands that were ''activated'' as a wind-blown-dust sources after harvest. This finding calls for revisions to the current wind-blown-dust-emission module, in which ''desert'' is designated to be the only land-cover category that can emit wind-blown dust.

Hsp70 and HSF-1 expression is altered in the tissues of pigs transported for various periods of times

Miao Zhang,Zhenhua Yue,Zhijun Liu,Ali Islam,Buriro Rehana,Shu Tang,Jörg Hartung,Endong Bao 대한수의학회 2012 JOURNAL OF VETERINARY SCIENCE Vol.13 No.3

The aim of this study was to assess changes of Hsp70 and HSF-1 protein and mRNA expression in stress-sensitive organs of pigs during transportation for various periods of time. Twenty pigs were randomly divided into four groups (0 h, 1 h, 2 h, and 4 h of transportation). A significant increased activity of AST and CK was observed after 1 h and 2 h of transportation. Histopathological changes in the heart, liver, and stomach indicated that these organs sustained different degrees of injury. Hsp70 protein expression in the heart and liver of transported pigs did not change significantly while it increased significantly (p < 0.05) in the stomach. Hsp70 mRNA levels decreased significantly (p < 0.05) in the heart after 4 h of transportation. However, mRNA expression increased significantly in the liver after 1 (p < 0.05) and 4 h (p < 0.01) of transportation, and increased significantly in the stomach of the transported pigs after 1, 4 (p < 0.01), and 2 h (p < 0.05). HSF-1 levels were reduced at 1 and 4 h (p < 0.05) only in the hearts of transported pigs. These results indicate that Hsp70 mediates distinct stress-related functions in different tissues during transportation.