Commercial production of thermoelectric (TE) modules features energy-intensive and time-consuming processes. Here, we propose a rapid, facile and low cost fabrication process for n-type single phase Bi 2 Te 2.7 Se 0.3 that combines self-propagating high-temperature synthesis (SHS) with the laser nonequilibrium 3D printing method based on selective laser melting (SLM). The optimal SLM processing window for high quality single layers has been determined. Results show that the chemical composition of the sample is very sensitive to the laser energy density (E V ) due to the selective vaporization of Se and Te. For energy densities E V of less than 33.3 J mm
À3, the composition of the SLM-processed samples is relatively stable. However, as E V exceeds 33.3 J mm À3 and increases further, the vaporization rate of Te and Se significantly increases and is much higher than that of Bi. Empirical formulae relating the chemical composition of the resulting materials with the values of E V are obtained and are used to predict the composition of the SLM-processed material. Most importantly, the temperature dependent TE properties of the SLM-fabricated bulk sample result in a maximum ZT value of 0.84 at 400 K, which is comparable to that of the commercially available material. The work has laid a foundation for the future utilization of this technique for the fabrication of Bi 2 Te 3 -based thermoelectric modules.
A comprehensive two-dimensional (2-D) separation system, coupling capillary reverse-phase liquid chromatography (cRPLC) to capillary isoelectric focusing (CIEF), is described for protein and peptide mapping. cRPLC, the first dimension, provided high-resolution separations for salt-free proteins. CIEF, the second dimension with an orthogonal mechanism to cRPLC afforded excellent resolution capability for proteins with efficient protein enrichment. Since all sample fractions in cRPLC effluents could be transferred to the CIEF dimensions, the combination of the two high-efficiency separations resulted in maximal separation capabilities of each dimension. Separation effectiveness of this approach was demonstrated using complex protein/peptide samples, such as yeast cytosol and a BSA tryptic digest. A peak capacity of more than 10 000 had been achieved. A laser-induced fluorescence (LIF) detector, developed for this system, allowed for high-sensitive detection, with a fmol level of peptide detection for the BSA digest. FITC and BODIPY maleimide were used to tag the proteins, and the latter was found better both for separation and detection in our 2-D system.
The manufacturing cost has been a bottle neck for broader applications of thermoelectric (TE) modules. We have developed a rapid, facile, and low cost method that combines noncontact dispenser printing with selective laser melting (SLM) and we demonstrate it on n-type Bi 2 Te 3 -based materials. Using this approach, single phase n-type Bi 2 Te 2.7 Se 0.3 thin layers with the Seebeck coefficient of À152 mV K À1 at 300 K have been prepared. Assembling such thin layers on top of each other, the performance of thus prepared bulk sample is comparable to Bi 2 Te 3 -based materials fabricated by the conventional techniques. Dispenser printing combined with SLM is a promising manufacturing process for TE materials.
Based on array CIEF (ACIEF) and a novel whole column imaging detection (WCID), a comprehensive 2-D system with laser-induced fluorescence was developed for protein mapping. By coupling capillary RPLC (CRPLC) as the first dimension and ACIEF as the second dimension, a high-throughput and high-resolution proteomic expression profiling was obtained. An array of up to 60 capillaries was assembled, with electrical connections made through filling small breaks, created on each capillary at positions of buffer reservoirs, with a porous polymer. A whole column image system with laser-induced fluorescence (LIF) was devised. Spot excitation was performed with a laser converted to produce linear light, and a CCD camera was employed to take images of the protein fluorescence during line laser scanning of the capillary array. Quantitative detection of thousands of focusing protein bands in the capillary array was achieved. Details on the capillary array fabrication and scanning LIF detection system devices are discussed. The efficiency of this CRPLC-ACIEF-LIF-WCID system was further demonstrated using samples of soluble proteins extracted from liver cancer tissue. The overall peak capacity was estimated to be around 18 000 in an analysis time of less than 3 h. The reproducibility of consecutive runs and different columns were assessed as having an RSD of 1.5% and 2.2% in focusing positions, respectively.
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