Search Results

You are looking at 11 - 20 of 27 items for :

  • "Continuous measurement" x
  • Chemistry and Chemical Engineering x
  • Refine by Access: All Content x
Clear All

Biotransformation of l-phenylalanine (l-1a) and five unnatural substrates (rac-1bf) by phenylalanine ammonia-lyase (PAL) was investigated in a novel microfluidic device (Magne-Chip) that comprises microliter volume reaction cells filled with PAL-coated magnetic nanoparticles (MNPs). Experiments proved the excellent reproducibility of enzymecatalyzed biotransformation in the chip and the excellent reusability of the enzyme layer during 14 h continuous measurement (>98% over 7 repetitive measurements with l-1a). The platform also enabled fully automatic multiparameter measurements with a single biocatalyst loading of about 1 mg PAL-MNP. Computational fluid dynamics (CFD) calculations were used to study the flow field in the chambers and the effect of unintended bubble formation. Optimal flow rate for l-1a reaction and specific activities for rac-1bf under these conditions were determined.

Restricted access

Abstract  

Continuous measurements of atmospheric222Rn were made for the past three years by the Environmental Measurements Laboratory (EML) at the Atmosphere/Ocean Chemistry Experiment site located at Tudor Hill, Bermuda and at the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory Mauna Loa Observatory. The222Rn analyzer is based on the two-filter tube method. At the Bermuda site, monthly median222Rn concentration range from 50 to 700 mBq m–3, and the concentrations vary seasonally, with a maximum in the winter and a minimum in the summer. The concentrations are significantly elevated when local winds traverse the island. At MLO, monthly median222Rn concentrations range from 100 mBq m–3 during the fall months to 400 mBq m–3 during the spring months. The springtime maximum values correspond to periods of rapid transport in the free troposphere from the Asian continent, corroborated by backward air mass trajectories. The222Rn data are also used to help decipher local daily upslope/downslope conditions present at MLO. This study illustrates the value of atmospheric222Rn monitoring, when screened through the filter of local meteorology, in studying the transport of continental air to the oceans, as well as the dynamics of local meteorological effects.

Restricted access

A very low level temperature derivative apparatus is described. It is able to give a true and continuous measurement of heating or cooling rate from room temperature up to 900° with a detection threshold as low as 30μ°Cs−1. This apparatus can be used for derivative thermal analysis and as slope temperature generator.

Restricted access

Summary  

There is an increasing need in industry, arising from both economic and environmental considerations, to reduce costs and improve product quality through the use of automation. The use of on-line analysis instrumentation provides plant operators with a means for continuous measurement and rapid response. This can result in better control of process efficiency, product quality and resource utilization, all of which produce significant economic and environmental benefits. On-line measurement of bulk elemental composition is important in many industrial applications and is best achieved with highly penetrating neutron-gamma techniques. This paper presents recent work by CSIRO Minerals on the development and implementation of such a technique, NITA (neutron inelastic-scattering and thermal-capture analysis). NITA is distinct from the more common PGNAA (prompt neutron gamma activation analysis) technique in its use of fast neutron sources to generate inelastic scattering reactions, and in its consequent ability to excite gamma-rays from industrially important elements such as carbon and oxygen. The paper will compare the features of NITA and PGNAA analysers and will discuss applications of NITA in industry, including the on-line analysis of composition in pyrometallurgical applications and the on-conveyor belt monitoring of cement raw meal and coal.

Restricted access

Application of microcalorimetry and chemometric analysis

Effects evaluation of angle and nail animal drugs on Bacillus subtilis growth

Journal of Thermal Analysis and Calorimetry
Authors: Xiaoyan Xing, Yanling Zhao, Weijun Kong, Yanwei Zhong, Dan Yan, Ping Zhang, Yumei Han, Lei Jia, Cheng Jin, and Xiaohe Xiao

tool for many biological investigations, the isothermal microcalorimetric technique directly determines the biological activity of a living system and provides a continuous measurement of heat production, which was important to evaluate the effects of

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Yumei Han, Dan Yan, Yanling Zhao, Cheng Peng, and Xiaohe Xiao

curves of living cells are obtained, which reflects the information of the metabolic processes [ 1 , 2 ]. Microcalorimetry can be employed to directly determine the biological activity of a living system and provide continuous measurement of heat

Restricted access

the sensor of movement to the data logger linked with computer. In such a way the continuous measurements were possible. The pastes prepared at water to solid ratio 0.40 (w/s; lowered from standard 0.5 to avoid bleeding), mixed in special blender to

Open access

sufficiently sensitive microcalorimeter, the metabolic processes of living cells can be studied by a direct method. Microcalorimetry can directly determine the biological activity of a living system and provide a continuous measurement of the heat production

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: X. X. Han, X. M. Jiang, Z. G. Cui, J. W. Yan, and J. G. Liu

thermogravimetric analyzer provided for the continuous measurement of sample mass as a function of temperature, and the rate of mass loss, namely derivative thermogravimetric (DTG) curve, was thus obtained as well. The Q5000IR thermogravimetric analyzer

Restricted access

Results observed for compressive strength shows the same trend as previously described in the evolution of heat released, with the advantage that this property allows continuous measurement of the influence of each variable on the hydration of cement with

Restricted access