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The polymerization of amino acids leading to the formation of peptides and proteins is a significant problem for the origin of life. This problem stems from the instability of amino acids and the difficulty of their oligomerization in aqueous environments, such as seafloor hydrothermal systems. We investigated the stability of amino acids and their oligomerization reactions under high-temperature (180-400°C) and high-pressure (1.0-5.5 GPa) conditions, based on the hypothesis that the polymerization of amino acids occurred in marine sediments during diagenesis and metamorphism, at convergent margins on early Earth. Our results show that the amino acids glycine and alanine are stabilized by high pressure. Oligomers up to pentamers were formed, which has never been reported for alanine in the absence of a catalyst. The yields of peptides at a given temperature and reaction time were higher under higher-pressure conditions. Elemental, infrared, and isotopic analyses of the reaction products indicated that deamination is a key degradation process for amino acids and peptides under high-pressure conditions. A possible NH(3)-rich environment in marine sediments on early Earth may have further stabilized amino acids and peptides by inhibiting their deamination.

Novel ternary nitride semiconductor MgSnN2 was synthesized using the metathesis reaction under high pressure (P = 5.5 GPa/T = 850 °C/1 h). MgSnN2 obtained in this study showed a rocksalt structure, although we have reported that ZnSnN2 synthesized using a similar method has a wurtzite structure. The (111) plane of MgSnN2 with a rocksalt structure is expected to match well with GaN (0001). The band gap of MgSnN2 is estimated to be 2.3 eV and it shows a distinct cathodoluminescence peak at room temperature. MgSnN2 can find potential use in photovoltaic absorber, in the emitting layer of a light‐emitting device, and photocatalyst or opaque pigment because the elements composing MgSnN2 are nontoxic and earth‐abundant. MgSnN2 powder synthesized in this study showed excellent crystallinity, proving that metathesis reaction under high pressure is a superior method for synthesizing novel multicomponent nitrides. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to examine the extractive, holocellulose, alpha cellulose, lignin, starch, and sugar contents of oil palm biomass and to evaluate its suitability in binderless particleboard production. In this study, bark, leaves, fronds, mid-parts and core-parts of the trunks were used to produce experimental binderless particleboard panels. Binderless particleboard panels were made with a target density of 0.80g/cm3 at a temperature of 180°C and a pressure of 12MPa in a computer controlled hot press. The modulus of rupture, the internal bond strength, the thickness swelling and the water absorption of the panels were evaluated. Fourier transform infrared spectroscopy and field emission scanning electron microscopy were used to characterize the properties of the raw materials and the manufactured panels. The chemical composition of the oil palm biomass consisted of high holocellulose, lignin, starch and sugar contents that have been found to aid in the production of binderless particleboard. The core-part of the trunk contained the highest amount of starch and total sugar. Samples made from the core-parts and fronds had sufficient modulus of rupture and internal bond strength to meet the Japanese Industrial Standard. The internal bond strength of the mid-part panels also met the standard. However, binderless board prepared from bark and leaves showed poor modulus of rupture and internal bond strength. Samples from the core-parts had the lowest thickness swell and water absorption but did not meet the above standard. The Fourier transform infrared spectroscopy spectra did not show any substantial difference between the raw materials and the manufactured panels. Field emission scanning electron microscopy indicated that the compressed cells varied between raw material types and showed the presence of compressed cells with some starch granules that facilitated adhesion. Based on the findings of this study, oil palm has the potential to be used to manufacture binderless panel products, and further study is required to improve its dimensional stability. [Copyright &y& Elsevier]