Analysis of umami taste and their contributing compounds in edible fungi based on electronic tongue, sensory evaluation, and chemical analysis.

Edible fungi are rich in nutrients and have unique umami taste, which varies with genotypes, growth conditions, and harvest time. In this study, umami compounds in 12 species of edible fungi are analyzed and identified by electronic tongue. Through principal component analysis and discriminant factor analysis, these 2 methods could be successfully distinguished the variety of 12 edible fungi. Besides, the umami intensity of edible fungi soup is also evaluated by sensory and chemical analysis methods, for example, Tricholoma matsutake is 5.60 ± 0.34 and 5.17 ± 0.38, Coprinus comatus is 7.70 ± 0.23 and 9.83 ± 0.34 through sensory evaluation and electronic tongue respectively, followed by establishing the correlation from the response data by PLS (partial least squares analysis). According to the PLS model, with a correlation coefficients of calibration models greater than 0.7 and the low root mean square error of calibration and root mean square error of prediction values, the results correlate well with each other. Therefore, we can indicate that the electronic tongue is able to analyze and evaluate the umami intensity of edible fungi to some extent.

Effect of Copper Sulfate and Sulfuric Acid on Blind Hole Filling of HDI Circuit Boards by Electroplating.

Here, in a certain high density interconnect (HDI) printed circuit board, the effect of copper sulfate and sulfuric acid on the filling effect of a blind hole with a certain diameter and depth was investigated by making a blind hole using a CO2 laser drilling machine, filling the blind hole via electroplating by simulating the electroplating line in a Halin cell, and observing the cross-section of a micro blind hole after polishing using metallographic microscope, as well as the effect of hole filling, are evaluated. The results show that, under the conditions of a certain plating solution formula and electroplating parameters (current density and electroplating time), the sag degree decreases with the increase in the copper sulfate concentration. When the concentration of copper sulfate increases from 210 g/L to 225 g/L, the filling effect is good and the sag degree is about 0. However, with the increase in sulfuric acid concentration, the sag increases gradually. When the sulfuric acid concentration is 25-35 g/L, both the sag and copper coating thickness are in a small range. Under appropriate electroplating conditions, a better blind hole filling effect can be obtained. The volume of blind hole has a certain effect on the diffusion and exchange of copper sulfate and sulfuric acid, as well as on the concentration distribution of additives.

A fleeting glimpse of the dual roles of SiB4 in promoting the hydrogen storage performance of LiBH4.

In this study, the positive effects and dual roles of SiB4 on the dehydrogenation and rehydrogenation performance of the LiBH4-SiB4 system are reported. Characterizations were performed through temperature programmed desorption mass spectrometry (TPD-MS), isothermal kinetics measurements, and XRD and FTIR analyses. For the hydrogen desorption from LiBH4, SiB4 played the role of a catalyst to kinetically facilitate the structural destabilization of LiBH4 and its intermediate phase Li2B12H12. Accordingly, a dehydrogenation capacity of 2.24 at. H/f.u. LiBH4 (close to 10.3 wt% H) was attained at a relative temperature of 350 °C. For hydrogen absorption to generate LiBH4, SiB4 was unexpectedly found to act as a reactant to thermodynamically improve the rehydrogenation process by reacting with LiH under moderate conditions of 10 MPa H2 and 400 °C, and a superior reversible capacity of 2.16 at. H/f.u. LiBH4 was achieved. These experimental results remind us to take into account the explicit role(s) of the employed components during the dehydrogenation and rehydrogenation reactions when designing a desirable LiBH4-based system.

Correlation between structural stability of LiBH4 and cation electronegativity in metal borides: an experimental insight for catalyst design.

Nanosized metal borides MBx (M = Mg, Ti, Fe, Si) are found to play an important role in enhancing the hydrogen storage performance of LiBH4 in this work. The hydrogen storage behavior and mechanism of these modified systems are investigated through TPD-MS, XRD, FTIR and SEM characterization methods. By introducing these metal borides into LiBH4 through ball milling, the systems display three dehydrogenation stages disclosing their similarity and distinction. The 1st stage starts at 190 °C, the 2nd stage ranges from 280 °C to 400 °C and the 3rd stage ends at 550 °C with a peak at round 440 °C similar to that of pristine LiBH4. Distinguishing features exist at the 2nd stage revealing the effectiveness of MBx in an order of MgB2 < TiB2 < FeB < SiB4. Significantly, reversibility up to 9.7 wt% is achieved from LiBH4 with assistance of SiB4. The catalytic effect of MBx is influenced by the Pauling electronegativity of M in MBx and the interfacial contact characteristic between LiBH4 and MBx. The larger electronegativity leads to an enhanced catalytic effect and consequently lower temperature at the major stage. In contrast to the components in the solid state, the molten LiBH4 promotes a catalytic effect due to a superior interfacial contact. These results provide an insight into designing high-performance catalysts applied to LiBH4 as a hydrogen storage material.