Plasma prefractionation methods for proteomic analysis and perspectives in clinical applications

Plasma is a rich source of biomarkers with clinical relevance. However, the wide dynamic range of protein concentration hinders the detection of low abundance proteins. Plasma prefractionation methods serve as indispensable tools to reduce plasma complexity, allowing the opportunity to explore tissue‐derived proteins which leak into the circulation. This review summarizes common approaches in plasma prefractionation methods for proteomic analysis and then discusses some considerations in plasma prefractionation for clinical applications, reviewing some examples of its use in clinical situations.     

Experimental study of dual fixed bed biochar-catalytic gasification with simultaneous feed of O2-steam-CO2 for synthesis gas or hydrogen production

The catalytic gasification of biochar was investigated in the presence of a Ni/SiO₂ catalyst in a fixed bed reactor with an O₂-steam-CO₂ gas feed. The effects of operating temperature, catalyst nickel loading and composition of O₂-steam-CO₂ feed gas on biochar carbon conversion and gas products were investigated. The results indicate that the highest biochar carbon conversion could be obtained at approximately 800 °C, whilst the 10% Ni/SiO₂ catalyst was shown to produce the greatest syngas yields. The presence of O₂ in the feed gas can result in slightly more CO in the gas product, whilst a higher steam content leads to more H₂ in the gas product. The CO₂ offered a benefit as an adjusting agent for achieving a desired H₂/CO ratio. No evidence of coke deposition on the catalyst was found under any of the tested conditions.     

Improvement of solid oxide fuel cell performance by using non-uniform potential operation

Theoretical study was carried out to investigate the possible improvement of SOFC performance by using a non-uniform potential operation (SOFC-NUP) in which the operating voltage was allowed to vary along the cell length. Preliminary results of a simple SOFC-NUP with a cell divided into two sections of equal size in term of range of fuel utilization (U_f) indicated that the SOFC-NUP can offer higher power density than an SOFC with uniform potential operation (SOFC-UP) without a reduction of the electrical efficiency. In this work, voltages and section splits were optimized to obtain the maximum power density of the SOFC-NUP. At the optimum splits (S_p,1 = 0.55 and S_p,2 = 0.45), the power density improvement as high as 9.2% could be achieved depending on the level of electrical efficiency. It was further demonstrated that the increase in the number of separated section (n) of the cell could increase the achieved maximum power density but the improvement became less pronounced after n > 3.     

Influence of stack arrangement on performance of multiple-stack solid oxide fuel cells with non-uniform potential operation

The performance of multiple-stack solid oxide fuel cells (SOFCs) with different stack arrangements is compared with respect to the presence of an in-stack pressure drop. It was demonstrated in our previous work that when a multiple-stack SOFC is arranged in series and the operating voltages are allowed to vary among the different stacks, an improved performance over a conventional SOFC (stacks arranged in parallel and operated under the same operating voltage) can be realized. Nevertheless, the differences in pressure drop and the required power for compression among the different operations were not taken into account. In the study reported here, it is demonstrated that the pressure drop in the stack depends not only on the feed rate and operating voltage, but also on the stack arrangement. The pressure drop in the anode channels is about half that in the cathode channels. The configuration of stacks in series with compressors installed only at the inlets of the first stack is the best option as it shows the highest electrical power generation. The pressure drops in the anode and cathode channels are about 4.7 and 3.75 times those in the corresponding channels of the conventional case with the stacks arranged in parallel. In addition, when considering the net obtained electrical power, it appears that multiple-stack SOFCs with stacks arranged in series are not as attractive as the conventional SOFC because they require much higher compression power. Therefore, it is suggested that a new stack design with a low pressure drop is required for the concept of multiple-stack SOFC with non-uniform potential operation to become practical.     

Field analysis of PSA O2–ozone production process for water recycling

The use of an oxygen generator based on pressure swing adsorption technology (PSA) has been investigated as an alternative method for supplying oxygen for onsite ozone production. During the investigation period of 1040 h, the oxygen purity from the PSA process fluctuated within a range of 90.5–93 O₂% (v/v). Using the working ratio of 2.8 mol of O₂ to 1 m³ of raw water, the PSA process in series with a corona discharge ozone generator yielded an oxidation–reduction potential of ca. 200 mV and a concentration of 22.8 mg/L dissolved oxygen. The average efficiency of the raw water treatment was as follows: 47% chemical oxygen demand removal, 78% biological oxygen demand removal, 36% sulphide removal and 34% colour removal. The operating cost of the PSA O₂ generation was reduced 3 times compared with the cost of high‐pressure oxygen cylinders.     

Thermodynamic analysis of combined unit of biomass gasifier and tar steam reformer for hydrogen production and tar removal

A combined unit of biomass gasifier and tar steam reformer (CGR) was proposed in this study to achieve simultaneous tar removal and increased hydrogen production. Tar steam reforming calculations based on thermodynamic equilibrium were carried out by using Aspen Plus software. Thermodynamic analysis reveals that when selecting appropriate operating conditions, exothermic heat available from the gasifier could sufficiently supply to the heat-demanding units including feed preheaters, steam generator and reformer. The effects of gasification temperature (T_gs), reforming temperature (T_ref) and steam-to-biomass ratio (S:BM) on percentages of tar removal and improvement of H₂ production were investigated. It was reported that the CGR system can completely remove tar and increase H₂ production (1.6 times) under thermally self-sufficient condition. The increase of H₂ production is mainly via the water–gas shift reaction.