The Fe(II)- and 2-oxoglutarate (2-OG)-dependent dioxygenases comprise a large and diverse enzyme superfamily the members of which have multiple physiological roles. Despite this diversity, these enzymes share a common chemical mechanism and a core structural fold, a double-stranded β-helix (DSBH), as well as conserved active site residues. The prolyl hydroxylases are members of this large superfamily. Prolyl hydroxylases are involved in collagen biosynthesis and oxygen sensing in mammalian cells. Structural-mechanistic studies with prolyl hydroxylases have broader implications for understanding mechanisms in the Fe(II)- and 2-OG-dependent dioxygenase superfamily. Here, we describe crystal structures of an N-terminally truncated viral collagen prolyl hydroxylase (vCPH). The crystal structure shows that vCPH contains the conserved DSBH motif and iron binding active site residues of 2-OG oxygenases. Molecular dynamics simulations are used to delineate structural changes in vCPH upon binding its substrate. Kinetic investigations are used to report on reaction cycle intermediates and compare them to the closest homologues of vCPH. The study highlights the utility of vCPH as a model enzyme for broader mechanistic analysis of Fe(II)- and 2-OG-dependent dioxygenases, including those of biomedical interest.

A computational fluid dynamics model was developed to investigate the hydrodynamic characteristics of a novel orthogonal fixed-valve tray, which offers a larger effective contact perimeter under the same orifice area than its previously reported counterparts. The liquid-gas phases were simulated in the Eulerian framework, with the interphase momentum transfer source term based on the experimentally obtained liquid hold-up correlation. The simulation results were consistent with the experimental data. In addition, the gas hold-up profile of this new design was compared with its triangular cousin under the conditions of a typical run, showing that the former has a higher froth height, which indicated better interphase contact on the tray.

An optical fiber water vapor sensor based on a distributed feedback (DFB) diode laser was reported. The DFB diode laser was internally driven by a low-frequency current to realize wavelength scanning; simultaneously, laser output was externally modulated through an electro-optic modulator to realize high-frequency intensity modulation. Measurement precision of water vapor concentration could be improved by two main aspects, absolute absorption profile and high signal-to-noise ratio. The experiment was carried out at 1 atm/296 K and the recovered absolute absorption profile of water vapor at 1368.597 nm was described by Voigt profile with a difference of 1%. A well linearity was achieved with an R-square of 0.9999 and the sensitivity for a 10-cm absorption length was achieved to be 6.7 x 10(-8) Hz(-1/2).

We present a theoretical model to analyze the impact of Rayleigh noise on Raman distributed temperature sensors (RDTS), which use the anti-Stokes and Stokes light or anti-Stokes component only as the demodulation signals. Based on this model, the effects of Rayleigh noise on temperature accuracy, sensitivity, and resolution are investigated both at only one point and in a section of the fiber. The analysis indicates that for RDTS demodulated by anti-Stokes light only, the temperature accuracy, sensitivity, and resolution decrease by about 1°C, 10%, and 0.25°C on the assumption that the Rayleigh noise accounts for 10% of the anti-Stokes intensity. Moreover, for RDTS demodulated by Stokes and anti-Stokes light, the temperature accuracy, sensitivity, and resolution decrease by about 1°C, 10%, and 0.2°C assuming that the Rayleigh noise in two paths is equal to 10% of the intensity of anti-Stokes and Stokes light. The analysis demonstrates that the impact of Rayleigh noise on sensing capacities of RDTS is non-negligible, thus providing a major contribution to the elimination of Rayleigh noise in RDTS.

We proposed and demonstrated a wavelet transform modulus maxima (WTMM) de-noising method to decrease the temperature error. In this scheme, the composition scale was determined simply by the WTMM amplitude variation with the growth of the decomposition scale at 30 °C, and the signal WTMM was obtained by the wavelet decomposition modulus on every decomposition scale based on the modulus propagating difference between the signal and noise. Then, we reconstructed the signal using the signal WTMM. Experimental results show that the proposed method is effective for de-noising, allowing for a temperature error decrease of about 1 °C at 40 °C and 50 °C comparing to the original data.

The impact of microwave sweeper power fluctuation in the BOTDA system has been theoretically analyzed and experimentally tested. And a novel method comparing real-time acquisition of probe wave power with a new algorithm to realize probe wave power normalization for eliminating this impact was proposed. The principle of the proposed method was described theoretically. And the contrast test between our new method and conventional one was carried out. The experiment results indicated that the temperature accuracy was effectively improved from ±5 °C to ±2 °C.

Operation of user was defined. The weight of operation was expressed. The variable quantity of user behavior was computed by weight. 3-ary vector data definition was expanded. Data item was defined by 4-ary vector in personal dataspace. Correlation of data for user was defined by weight. Current weight of data was defined by initial weight and variable quantity of user operation. A library dataspace model was designed. The weights of data were verified by using a sample in the library dataspace for ten days. The result proved the correlation of data was very important and useful in personal dataspace. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4949

In order to eliminate the non-commutative errorwhich generatesin calculating navigationparameterbased onquaternion algorithm,the navigation algorithm based on screw theory is studied inthis paperto meet the needof high-precision navigation.Navigation solver mathematical model of SINSis established.Based on screw compensation algorithm, the simulationwith the trajectory data of the shellhad been done. And it had been compared to the quaternion rotation vector method.The simulation results show that compared to the rotation vector algorithm, the accuracy of attitude has little difference,but the accuracy ofvelocity and the accuracy of position are both relatively higher precision.

Ensuring the synchronization of backscattered Raman light and improving the sampling rate are of great importance to improve the spatial resolution of a distributed Raman temperature measurement system. To keep the synchronization of the Anti-Stokes and Stokes light and improve the sampling rate, four effective methods are proposed in this paper. First, the asynchrony caused by the difference in the hardware is eliminated by attaching a fiber to the pigtail of APD, which detects the earlier arriving signal. Next, the data acquisition card chooses different sampling rates for the Anti-Stokes and Stokes light according to the velocity of propagation. Then, a new algorithm is adopted to decrease the difference in the fiber position between the Anti-Stokes and Stokes signals. Finally, the optical switch with different length of pigtails is applied to improve the sampling rate without upgrading the hardware of data acquisition card. By theoretical analysis and experimental simulation, the proposed measures in this paper can improve the spatial resolution effectively.

The relational dataspace model was researched. A dataspace model-iDM was discussed. The advantages of dataspace model iDM were analyzed. Data model Vertical and Corespace were researched deeply. A dataspace system OrientSpace created by Vertical and Corespace was discussed, and it was analyzed.

The influence of the wavelength dispersion on the temperature accuracy of the Raman distributed temperature sensor system (RDTS) is analyzed in detail, and a simple correction algorithm is proposed to compensate the fiber position error caused by the wavelength dispersion. The principle of the proposed algorithm is described theoretically, and the correction on each point along the entire fiber is realized. Temperature simulation results validate that the temperature distortion is corrected and the temperature accuracy is effectively improved from ±5 °C to ±1 °C.

3-ary vector data definition was researched. 3-ary vector data definition was expanded. Data items were defined by 4-ary vector in dataspace. Data correlation for object was defined by weight. A library dataspace model was designed. Data weights were verified by using articles in library. The result proves weight of data can measure the correlation of data.

Dataspace integration is the basis of building dataspace. The new features of data were discussed. Theory of dataspace was researched. The structure of dataspace integration was proposed by analyzing the characters of dataspace. Dataspace integration was researched deeply by data model, correlation and relationship discovery.

A method for precise face detection and segmentation is presented combining with the particle swarm optimization. In order to extract face feature precisely, the method uses two key technologies: skin color segmentation and particle swarm search. The experimental results show that this method can eliminate the interference factor, and improve the accuracy of expression recognition, especially well for some single expression recognition.

4-ary vector expression was defined by 3-ary vector to describe subject and data item in dataspace. Association method between subject and data item was represented. Correlation of data item was defined by 4-ary vector. Correlation and association way between data items were represented by 4-ary vector. The validity of these methods was verified in technical document library.

A novel algorithm of measuring the Rayleigh noise for the optic fiber Raman distributed temperature sensor (RDTS) systems is proposed. This new algorithm is available to solve the temperature measurement inaccuracy caused by the Rayleigh noise. The impact of Rayleigh noise on the temperature measurement accuracy is revealed theoretically for the first time. Based on this novel algorithm, experiments are performed to figure out the Rayleigh noise and validate its impact on temperature measurement accuracy. The experiment results indicate that the Rayleigh noise occupies about 15% of the signal light (anti-Stokes), which is in accord with the computation result based on the device parameters, and the temperature measurement error could be reduced from about 7% to less than 2% by eliminating the Rayleigh noise.

Conveying vessels, which are widely used in pneumatic systems, feature gas–solid flow with intensive inter-phase interactions and complex flow patterns. In this study, a two-fluid model was used to simulate flow behaviors in an experimental vessel. To model the gas phase, a k-ε turbulent model and the particle phase kinetic theory of granular flow were used. Three hydraulic stages were indicated: the rising, static and declining phases. Flow regimes similar to a spouted bed were formed near the wall, which became increasingly stable over time. Unstable flow regimes that consisted of bubbles and slugs were formed near the central part of the vessel. The velocity distributions of the gas and particles, the pressure profile and the secondary flow are described. A fitted curve of the output and input was obtained, and the influences of inlet conditions, such as velocity and pressure, were also investigated.

The spherical gold nanoparticles (NPs) were synthesized by reducing aqueous chloroauri acid (HAuCl4) solution with Magnetospirillum gryphiswaldense MSR-1 at room temperature. The size of the gold NPs can be controlled by varying the pH value of the biosynthesis solution and the initial mental concentration. Transmission electron microscopy (TEM) analysis revealed that lower pH values and initial concentrations of Au (III) were individually responsible for limiting nano-gold particle size. It was also observed that the spherical gold NPs formed on the cell wall in the size range of 10-40 nm. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis of the gold NPs confirmed the formation of metallic gold. The ongoing work is to synthesize gold NPs by using Bacillus subtilis and explore the external and internal factors which may control the size and shape of them.

Washing oil, one of the important distillation cut of coal tar, consists of a series of high value-added components which can form azetropic and eutectic system, making it impossible to separate certain components completely by normal distillation. In this work, a scheme coupling distillation with crystallization to deal with this cut for pure chemicals is simulatively investigated before an industrial design. By the aid of this research, a 25Kt/a pilot scale unit was successfully designed which is now running with alpha-methyl-naphthalene, beta-methyl-naphthalene, fluorene, dibenzofuran and acenaphthylene in high purity as main products and naphthalene fraction, medium washing oil (dimethylnaphthalene) and heavy washing oil as by-products.

A low-cost single-axis temperature controlled turntable for detecting full-scale-temperature performance of FOG was developed. The eccentric shaft rotation mechanism was employed to achieve the turntable a periodic sinusoidal angular velocity swing. The turntable control system was developed using the microcontroller as the core, and the system had the functions of real-time temperature detection, swing amplitude and frequency control, temperature rise speed control and so on. The PC control software was also designed utilizing LabVIEW on the basis of the FOG test methods provided by national military standard, and the product test was implemented directly by running the control software. After the turntable parameter calibration was carried out applying the high-precision temperature control turntable and the standard gyroscope, the results of the tests on multiple gyroscopes indicated the stability of the turntable performance and the credibility of test results. With the advantages of small volume, simple operation approach, low power consumption and integrated testing approach, the turntable improved the efficiency of detection.