• Title/Summary/Keyword: Wales

Search Result 478, Processing Time 0.026 seconds

Characterization of $lac^+$ $gal^+$ Strains of Zymomonas mobilis for Ethanol Production from Lactose

  • Cho, Dong-Wuk;Delaney, Stephen-F.
    • Journal of Microbiology and Biotechnology
    • /
    • v.1 no.1
    • /
    • pp.12-16
    • /
    • 1991
  • Previously RP1::Tn951 which is a derivative of RP1 containing the lactose transposon Tn951 was introduced into Z. mobilis strain ZM6l00, and RP1::Tn951 was integrated into its genome to yield ZM6306. The galactose operon was incorporated into ZM6306 to yield ZM6307 for more efficient utilization of lactose. Batch culture study has been carried out on Z. mobilis strains, ZM6306 ($lac^+$ ) and ZM6307 ($lac^+$ , $gal^+$ ), which can convert lactose directly to ethanol. Using a medium containing 80 gㆍ$1^{-1}$ glucose and 40 gㆍ$1^{-1}$ lactose, it was found that ZM6306 and ZM6307 produced maximum ethanol concentration of 40 gㆍ$1^{-1}$ and 42 gㆍ$1^{-1}$, respectively, whereas parent strain ZM6 produced 37 gㆍ$1^{-1}$.

  • PDF

Improved Flux and Torque Estimators of a Direct Torque Controlled Interior PM Machine with Compensations for Dead-time Effects and Forward Voltage Drops

  • Sayeef, Saad;Rahman, M.F.
    • Journal of Power Electronics
    • /
    • v.9 no.3
    • /
    • pp.438-446
    • /
    • 2009
  • The performance of direct torque controlled (DTC) interior permanent magnet (IPM) machines is poor at low speeds due to a few reasons, namely limited accuracy of stator voltage acquisition and the presence of offset and drift components in the acquired signals. Due to factors such as forward voltage drop across switching devices in the three phase inverter and dead-time of the devices, the voltage across the machine terminals differ from the reference voltage vector used to estimate stator flux and electromagnetic torque. This can lead to instability of the IPM drive during low speed operation. Compensation schemes for forward voltage drops and dead-time are proposed and implemented in real-time control, resulting in improved performance of the space vector modulated DTC IPM drive, especially at low speeds. No additional hardware is required for these compensators.

Systematic Review of Sustainable Knowledge Transfer Process in Government-Industry-Academia Consortium

  • Faisal, Rouhi;Chong, Aik Lee;Yee, Angelina Seow Voon
    • Asian Journal of Innovation and Policy
    • /
    • v.6 no.3
    • /
    • pp.295-312
    • /
    • 2017
  • The purpose of this case study is to understand the sustainability practices of knowledge transfer process at the Malaysian government-industry-academia consortium. At this stage in the research, the R&D consortium is defined as an established entity by two or more organizations that pool resources and shared decision making for cooperative research and development activities. In attempts to understand the formation, outcomes and sustainability of the sustainable knowledge transfer process, this paper conducted a systematic literature review based on Gough, Oliver and Thomas systematic reviews protocol. From the review, the data were enriched and enhanced with a better understanding of sustainable knowledge transfer process. The systematic review resulted in identifying six factors including internal and external perspectives. However, key sustainability factors are not only directly influencing KTP, and the consortium, but are also mediated by other organisational variables.

Free vibration analysis of multiple open-edge cracked beams by component mode synthesis

  • Kisa, M.;Brandon, J.A.
    • Structural Engineering and Mechanics
    • /
    • v.10 no.1
    • /
    • pp.81-92
    • /
    • 2000
  • This study is an investigation of the effect of cracks on the dynamical characteristics of a cantilever beam, having multiple open-edge transverse cracks. The flexibilities due to crack have been identified for several crack depths and locations. In the study the finite element method and component mode synthesis methods are used. Coupling the components is performed by a flexibility matrix taking into account the interaction forces. Each component is modelled by cantilever beam finite elements with two nodes and three degrees of freedom at each node. The results obtained lead to conclusion that, by using the drop in the natural frequencies and the change in the mode shapes, the presence and nature of cracks in a structure can be detected. There is some counter-evidence, however, that the effects due to multiple cracks may interact to make detection more difficult than for isolated cracks.

Direct Ritz method for random seismic response for non-uniform beams

  • Lin, J.H.;Williams, F.W.;Bennett, P.N.
    • Structural Engineering and Mechanics
    • /
    • v.2 no.3
    • /
    • pp.285-294
    • /
    • 1994
  • Based on a fast and accurate method for the stationary random seismic response analysis for discretized structures(Lin 1992, Lin et al. 1992), a Ritz method for dealing with such responses of continuous systems in developed. This method is studied quantitatively, using cantilever shear beams for simplicity and clarity. The process can be naturally extended to deal with various boundary conditions as well as non-uniform Bernoulli-Euler beams, or even Timoshenko beams. Algorithms for both proportionally and non-proportionally damped responses are described. For all of such damping cases, it is not necessary to solve for the natural vibrations of the beams. The solution procedure is very simple, and equally efficient for a white or a non-white ground excitation spectrum. Two examples are given where various power spectral density functions, variances, covariances and second spectral moments of displacement, internal force response, and their derivatives are calculated and analyses. Some Ritz solutions are compared with "exact" CQC solutions.

Parallel computation for transcendental structural eigenproblems

  • Kennedy, D.;Williams, F.W.
    • Structural Engineering and Mechanics
    • /
    • v.5 no.5
    • /
    • pp.635-644
    • /
    • 1997
  • The paper reviews the implementation and evaluation of exact methods for the computation of transcendental structural eigenvalues, i.e., critical buckling loads and natural frequencies of undamped vibration, on multiple instruction, multiple data parallel computers with distributed memory. Coarse, medium and fine grain parallel methods are described with illustrative examples. The methods are compared and combined into hybrid methods whose performance can be predicted from that of the component methods individually. An indication is given of how performance indicators can be presented in a generic form rather than being specific to one particular parallel computer. Current extensions to permit parallel optimum design of structures are outlined.

Computer Aided Design of RC Structures

  • Islam, S.M. Shahidul;Khennane, A.
    • International Journal of Concrete Structures and Materials
    • /
    • v.7 no.2
    • /
    • pp.127-133
    • /
    • 2013
  • After reviewing the background and motivations for using modern computational methods for the design of reinforced concrete structures, an algorithm making use of the object oriented programming language Python and professionally developed finite element software is presented for the sizing and placement of the reinforcement in RC structures. The developed method is then used to design the reinforcement of a deep beam. To validate the design, two identical deep beam specimens were manufactured with the obtained steel, and then tested in the laboratory. It was found that the experimental results corroborated those predicted with the finite element design method.

The Prediction and Verification of an Urban Air Quality Model for Ozone Forecasting over the Sydney Basin

  • Speer, Milton S.;Leslie, Lance M.
    • Proceedings of the Korean Environmental Sciences Society Conference
    • /
    • 2003.11a
    • /
    • pp.212-215
    • /
    • 2003
  • The aim of this study was to test the air quality modelling system (HIRES-AIRCHEM) of The University of New South Wales particularly with regard to forecast ozone distribution. This was achieved by assimilating the New South Wales State EPA emissions inventory consisting of road and non-road sources and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA's goal of 80ppb on several occasions. The model forecasts of ozone distribution verified well with the EPA's ozone readings. This result has important implications for possible future use of the system as a tool for routinely assessing air quality.

  • PDF

Analytical Model of Conduction and Switching Losses of Matrix-Z-Source Converter

  • You, Keping;Rahman, M.F.
    • Journal of Power Electronics
    • /
    • v.9 no.2
    • /
    • pp.275-287
    • /
    • 2009
  • This paper investigates analytical models of Conduction and Switching Losses (CASLs) of a matrix-Z-source converter (MZC). Two analytical models of the CASLs are obtained through the examination of operating principles for a Z-source inverter and ac-dc matrix converter respectively. Based on the two models, the analytical model of CASLs for a MZC is constructed and visualized over a range of exemplified operating- points, each of which is defined by the combination of power factor (pt) and modulation index (M). The model provides a measurable way to approximate the total losses of the MZC.

A Study on the Shrinkage and Dimensional Characteristics of the Weft Knitted Fabrics with Polylactic acid(PLA) Yarn (Polylactic acid(PLA) 위편성물의 수축특성과 형태안정성에 관한 연구)

  • Choi, Jae-Woo;Jang, Bong-Sik;Lee, Eun-Woo
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.16 no.2
    • /
    • pp.47-52
    • /
    • 2013
  • Aim of this study is to investigate the dimensional and shrinkage characteristics of the weft knitted fabrics with Polylactic acid(PLA) knitted yarn. This PLA knitted yarn was made of the biodegradability fiber. The structure of weft knitted fabrics that was utilized for this study is the plain stitch, which is the most basic structure among all weft knitted fabrics. As the stitch length is shorter, the stitch density, courses density, and wales density are more increasing. The stitch density increased as pre-treatment process and dyeing process progressed. On the contrary, the heat setting process made it decreasing. The MR(Machine Relaxation) and DR(Dry Relaxation) standard area shrinkage were increasing as wet process progressed and as the stitch lengths are long.