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The current disposal of fish processing waste is causing environmental problems that have become an issue of public concern. Fish waste could be utilized for production of animal feed, biodiesel, natural pigments, food products and pharmaceuticals.Major attention was also directed to the recovery of valuable biomolecules such as collagen ω,-3 fatty acid, trypsin, chymotrypsin and elastase. Among these molecules, pepsin is one of the most beneficial and useful biomolecule that can be recovered from fish wastes.Pepsin is important aspartic proteases with many unique characteristics. It has several industrial applications including collagen extraction, cheese making, fish silage making, fish processing as well as use in medical research. Fish pepsin is primarily present in fish stomach and has a characteristic pH optimum of 2.0-4.0, distinct pH stability ≤ 6.0, a distinct optimum temperature of 30-55ºC and specific thermal stability ≤ 40-50ºC. Pepstatin A can strongly inhibit the pepsin activity while PMSF, E-64 and EDTA have a negligible impact. SDS, cysteine and aliphatic alcohols, have been identified as effective inhibitors while ATP, molybdate, NaCl, MgCl 2 , and CaCl 2 do not inhibit the activity of pepsin. Pepsin is widely applied in collagen extraction, in digestibility therapy,as rennet substitute and. At present, conventional method and innovative method have been developed for fish pepsin recovery. In the conventional method (ammonium sulfate), the partition of pepsinogen (PG) is mainly based on (a) crude enzyme extraction by homogenization and centrifugation, (b) purification of PG by gel filtration and anion exchange chromatography and (c) activation of PG under the acidic condition. The innovative recovery is based on aqueous two-phase system (ATPS). The conventional method is used for high purification while the ATPS is used for partial purification. Enzyme activity and concentration, specific activity (SA), purification factor (PF), molecular weight, and homogeneity, isoelectric point (pI) and are used to assay fish pepsin.

The sudden enhancements of magnetic strength, named magnetic peaks (MPs), are often observed in the magnetosheath of magnetized planets. They are usually identified as flux ropes (FRs) or magnetic mirror mode structures. Previous studies of MPs are mostly on the magnetohydrodynamics (MHD) scale. In this study, an electron scale MP is reported in the Earth magnetosheath. We present a typical case with a scale of ~7 electron gyroradii and a duration of ~0.18 s. A strong magnetic disturbance and associated electrical current are detected. Electron vortex is found perpendicular to the magnetic field line and is self‐consist with the peak. We use multipoint spacecraft techniques to determine the propagation velocity of the MP structure and find that the magnetic peak does propagate relative to the plasma (ion) flow. This is very different from the magnetic mirror mode that does not propagate relative to the plasma flow. Furthermore, we developed an efficient method that can effectively distinguish “magnetic bottle like” and “FRs like” structures. The MP presented in this study is identified as magnetic bottle like type. The mechanism to generate the electron scale magnetic bottle like structure is still unclear, suggesting that new theory needs to be developed to understand such small‐scale phenomena.

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The advancement in science and technology has led to luffa sponge (LS) being widely used as a natural material in industrial application because of its polyporous structure and light texture. To enhance the utility of LS fibers as the reinforcement of lightweight composite materials, the current study investigates their water absorption, mechanical properties, anatomical characteristics and thermal performance. Hence, moisture regain and tensile properties of LS fiber bundles were measured in accordance with American Society for Testing and Materials (ASTM) standards while their structural characteristics were investigated via microscopic observation. Scanning electron microscopy (SEM) was used to observe the surface morphology and fractured surface of fiber bundles. The test results show that the special structure where the phloem tissues degenerate to cavities had a significant influence on the mechanical properties of LS fiber bundles. Additionally, the transverse sectional area occupied by fibers in a fiber bundle (SF), wall thickness, ratio of wall to lumen of fiber cell, and crystallinity of cellulose had substantial impact on the mechanical properties of LS fiber bundles. Furthermore, the density of fiber bundles of LS ranged within 385.46–468.70 kg/m3, significantly less than that of jute (1360.40 kg/m3) and Arenga engleri (950.20 kg/m3). However, LS fiber bundles demonstrated superior specific modulus than Arenga engleri.