Metabolic engineering of S. pombe via CRISPR-Cas9 genome editing for lactic acid production from glucose and cellobiose

We constructed D-lactic acid (D-LA) producing Schizosaccharomyces pombe using CRISPR-Cas9 system. Two PDC genes, intact L-LDH, a minor gene of alcohol dehydrogenase (SPBC337.11) were disrupted to attenuate ethanol production pathway. To increase the cellular supply of acetyl-CoA, an important metabolite for growth, we introduced bacterial acetylating acetaldehyde dehydrogenase enzyme genes. Two kinds of acetaldehyde dehydrogenase genes from Escherichia coli, mhpF and eutE, were expressed. D-LA production was achieved by expressing D-lactate dehydrogenase gene from Lactobacillus plantarum. The engineered strains efficiently consumed glucose and produced 25.2 g/liter of D-LA from 35.5 g/liter of consumed glucose with the yield of 0.71 g-D-LA / g-glucose. Finally, we expressed beta-glucosidase by cell surface display techniques, and the resultant strain produced 24.4 g/L of D-LA from 30 g/L of cellobiose in minimal medium with the yield of 0.68 g-D-LA / g-glucose. This is the first report to generate metabolically engineered S. pombe strain using CRISPR-Cas9 system and we showed the possibility of S. pombe for the production host cell of value-added chemicals

Improved Analysis of Manganese in Steel Samples Using Collinear Long–Short Double Pulse Laser-Induced Breakdown Spectroscopy (LIBS)

A long-short double pulse laser-induced breakdown spectroscopy (long-short DP-LIBS) method was employed to improve the performance of LIBS for the measurement of manganese in steel samples. The long pulse was generated by a Nd:YAG laser which was operated at free runing (FR) mode. To investigate the detection ability without sample preparation, the steel washers were tested using SP-LIBS and long-short DP-LIBS, respectively. The measurement results show that the long-short DP-LIBS method was able to record clear spectra from the rusty steel washers. The steel washers were also measured after the polishing process. The measurement results show that the signal intensity was enhanced by long-short DP-LIBS. Through the observation with scanning electron microscope (SEM) on the laser craters, the results suggest that the improvement of detection ability can be attributed to the pre-radiation effect of long-pulse laser beam. Next, the analytical performance for quantitative measurement of manganese was evaluated by employing ten standard steel samples. The results show that the linearty fit (R2) of calibration curve is 0.988 for long-short DP-LIBS, whereas, R2 is only 0.810 for SP-LIBS under the same measurement conditions. The five times repeated measurement results show that the average Relative Standard Deviation (RSD) of the tested samples is 29.3% for SP-LIBS and is 10.5% for long-short DP-LIBS. The prediction results also show that the average Relative Error of Prediction (REP) is 94.9% for SP-LIBS and it 4.9% for long-short DP-LIBS. The experimental results in current work demonstrate that long-short DP-LIBS is promising for the on line measurement of steel in the steelmaking plant

Variations in Δ14C of POC in Waters from the Upper to Lower Ishikari River

[研究報告

Feasibility Investigation for Online Elemental Monitoring of Iron and Steel Manufacturing Processes using Laser-Induced Breakdown Spectroscopy

The metallurgical industries are very important for social development. In order to improve the metallurgical techniques and quality of products, the real-time analysis and monitoring of iron and steel manufacturing processes are very significant. Laser-induced breakdown spectroscopy (LIBS) has been studied and applied for the contents measurement of iron and steel. In this paper, the remote open-path LIBS measurement was studied under different sample temperature, lens to target distance (LTD), sample angle conditions to clarify its online measurement features. The 3D profile measurement system of parallel laser beam fringes projection was also developed to measure the sample profile at different sample temperature. The measurement results demonstrated the robustness of remote open-path LIBS system and 3D profile measurement system. However, the correction is necessary to enhance the detection ability of LIBS online measurement. In order to improve the precision and accuracy of real-time elemental measurement, an innovative co-axial laser beam measurement system combining LIBS and 3D profile techniques is proposed to automatically adjust the focus unit and measure the sample components. The further study of this promising method will be developed for online application of iron and steel manufacturing processes

Detection Improvement of Unburned Carbon Content in Fly Ash Flow Using LIBS with a Two-Stage Cyclone Measurement System

Fly ash contents can be considered as a basis for optimal and stable boiler combustion control and fly ash quality control in power plant, especially the unburned carbon in fly ash. The real-time and quantitative measurement of contents in fly ash was studied using a constructed two-stage cyclone measurement system and detected using laser-induced breakdown spectroscopy(LIBS) technique. The surrounding gas effect, such as CO2 effect on unburned carbon content, was studied comprehensively in this paper. The CO2 effect was eliminated using this proposed combination method of two-stage cyclone measurement system and LIBS with 1ns pulse-width laser according to the efficient gas-particle separation and the controlled laser-induced plasma processes of particle flow. The quantitative analysis was improved using the plasma temperature correction method with the intensity ratio of the emission pair from magnesium as a plasma temperature indicator. The measurement of unburned carbon content in fly ash with temperature correction method presented the concordant results analyzed by chemical analysis method. It is demonstrated the feasibility and improved detection ability for the real-time measurement of fly ash contents in power plant

Quantitative Elemental Analysis Using Long-Short Double-Pulse Laser Induced Breakdown Spectroscopy

鉄鋼プロセス，ボイラなどの様々な産業プロセスにおいて，物質の元素組成をリアルタイムで計測可能な技術が求められている．鉄鋼プロセスでは，鉄鉱石，コークス，石灰石などを原料として，鋼板などを製造する過程で各プロセス中の成分組成を計測することが求められ，溶融金属の組成などをリアルタイム制御することなどが重要となる．しかし，現在まで，これらの産業プロセスで元素組成をリアルタイムで計測可能な技術や装置は実用化されていない．レーザーを用いた非接触，リアルタイム計測方法として，レーザー誘起ブレークダウン分光法(Laser Induced Breakdown Spectroscopy，LIBS)がある．本研究では，LIBSを用いた元素組成の定量計測を目的に，ロング・ショートダブルパルスLIBSの開発を行った．本手法を鋼材中のマンガン及び炭素計測に適用し，計測の安定性，定量性に優れた特性を有することを実証した．The understanding of the controlling factors is becoming more important to improve the efficiency of industrial systems including steel-making processes, boilers and so on. Laser diagnostics such as laser-induced breakdown spectroscopy (LIBS) makes it possible to monitor these parameters due to their fast response, high sensitivity, and non-contact features. In this study, a new collinear long and short double pulse LIBS method was developed to improve the detection ability and the measurement accuracy by the control of the plasma cooling process using the long pulse-width laser radiation. The plasma generated by the short pulse-width laser is stabilized and maintained at high temperature during the plasma cooling process by long pulse-width laser radiation. The method was demonstrated to have better measurement stability and quantitative measurement characteristics for Manganese and Carbon measurement in the steel samples compared to the normal single pulse LIBS method

Matrix-POL architecture for integrated power supply

In this study, integrated H-bridge converter with the Matrix-POL power supply system is proposed. From the simulation results, the validity of the Matrix-POL is revealed. The results revealed that the fast response to the load current and the voltage change can be done with duty and parallel number control by the proposed system.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201

Unburned carbon measurement in fly ash using laser-induced breakdown spectroscopy with short nanosecond pulse width laser

The unburned carbon in fly ash is one of the important factors for the boiler combustion condition. Controlling the unburned carbon in fly ash is beneficial for fly ash recycle and to improve the combustion efficiency of the coal. Laser-induced breakdown spectroscopy (LIBS) technology has been applied to measure the fly ash contents due to its merits of non-contact, fast response, high sensitivity, and real-time measurement. In this study, experimental measurements have been adopted for fly ash flows with the surrounding gases of N2 and CO2, while the CO2 concentration varified to evaluate the CO2 effect on the unburned carbon signal from fly ash powder. Two kinds of pulse width lasers, 6ns and 1ns, were separately adopted to compare the influence of laser pulse width. Results showed that compared with 6ns pulse width laser, plasma temperature was lower and had less dependence on delay time when using 1ns pulse width laser, and spectra had more stable background. By using 1ns pulse width laser, the emission signal from surrounding CO2 also decreased because of the less surrounding gas breakdown. The solid powder breakdown signals also became more stable when using 1ns pulse width laser. So it is demonstrated that 1ns pulse width laser has the merits for fly ash flow measurement using LIBS