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Bitter cassava (Manihot glaziovii) has the potential to be converted into bioethanol. However, the distillation process can only purify it to 95% bioethanol. Therefore, it is necessary to carry out an adsorption process to obtain 99.8% bioethanol. This study aimed to investigate the effect of bitter cassava starch hydrolysis time and coral rock in the distillation column on glucose and bioethanol concentrations, respectively. Additionally, the study discussed the effect of adsorbent height (60, 80, 100, or 120 cm) in the adsorption column on bioethanol concentration. There are three main stages for obtaining fuel-grade bioethanol: (i) bitter cassava hydrolysis, (ii) bioethanol production, and (iii) bioethanol purification (distillation and adsorption). Zeolite 4A and natural zeolite were used as adsorbents in this study. The results showed that the best fermentation was obtained at 90 hours, resulting in an ethanol concentration of 13.82% (v/v), which could be purified up to 95.64% through distillation. Furthermore, further purification (adsorption) could extend fuel-grade bioethanol (99.62% and 98.42%). Another analysis also indicated that zeolite 4A was more feasible than natural zeolite for producing fuel-grade bioethanol.

Coral rock of biological origin exhibits distinctive mechanical behavior compared to that of conventional mineral rocks. Quasi-static and impact loading tests were conducted to investigate the mechanical properties of coral rock using a servo-hydraulic device and a split Hopkinson pressure bar (SHPB) apparatus. The dependence of the dynamic compressive strength, elastic modulus and energy absorption were quantitatively analyzed with respect to loading strain rate. The coral rock is characterized by a high porosity of 50.99 (± 5.60)% and a low bulk density of 1.31 (± 0.07) g cm−3 because of biological sedimentary. Both the quasi-static and dynamic stress–strain curves contain more pronounced compaction portion than dense rocks due to its special porous skeleton structure. The dynamic increase factor (DIF) of strength increases from 1.88 to 3.76 with the strain rate increasing from 117 to 334 s−1, which could be expressed with a parabolic function. The dynamic elastic modulus exhibits an overall linear increasing trend with loading strain rate. The ratio of reflected energy to incident energy is positively related with the strain rate while the absorbed ratio is roughly negatively correlated with strain rate with a value less than 0.08. The specific energy absorption (SEA) is found to be proportional to the logarithm of the loading strain rate. It seems that the failure mode of coral rock under both quasi-static and dynamic compression is more dependent on inherent flaws like pre-existing pores, growth lines, weak bonding areas than loading strain rate. Nevertheless, the dominant failure mode in microscopic scale for coral rock at higher strain rate is still trans-granular fracture by means of SEM. [ABSTRACT FROM AUTHOR]

The present paper reports the first record of the narrowbar reefgoby, Priolepis profunda (Weber, 1909) from the Indian coast. Two specimens (33.5 and 38.5 mm of TL), were caught during a demersal trawling survey conducted in the area between 9°40.7′N, 76°05.8′E and 9°45.1′N, 76°03.9′E at 33 m in June 2017. The specimens were collected from a coral rock which entered in the trawl net during the demersal resources survey. The morphological descriptions of the specimens collected are compared with those of existing records.

The present paper reports the first record of the narrowbar reefgoby, Priolepis profunda (Weber, 1909) from the Indian coast. Two specimens (33.5 and 38.5 mm of TL), were caught during a demersal trawling survey conducted in the area between 9°40.7′N, 76°05.8′E and 9°45.1′N, 76°03.9′E at 33 m in June 2017. The specimens were collected from a coral rock which entered in the trawl net during the demersal resources survey. The morphological descriptions of the specimens collected are compared with those of existing records. [ABSTRACT FROM AUTHOR]

Coral rock is characterized by a high porosity of 48.51 ± 5.43% and a low compressive strength of 9.91 MPa due to its biological origin. To experimentally investigate the uniaxial compressive behaviors of both air-dried and fully saturated coral rocks, the quasi-static and dynamic compression tests were performed employing an electro-hydraulic servo-controlled device and a split Hopkinson pressure bar (SHPB) apparatus. The combined effects of strain rate and water saturation on the mechanical properties of coral rock were assessed in terms of the uniaxial compressive strength, Young's modulus, brittleness, energy dissipation as well as the failure pattern. The dynamic uniaxial compressive strength and Young's modulus of saturated coral rocks is consistently lower than those under dry condition, while the losses in them reduces with an increase in stain rate. The coral rock behaves in a more brittle manner in dry state than in saturated state, which is validated by the digital image correlation (DIC) in conjunction with high-speed camera images. Likewise, the change in brittleness or specific energy absorption (SEA) with strain rate under dry and saturated conditions exhibits a similar trend to the dynamic compressive strength. Furthermore, the dynamic failure of dry coral rock appears to be more dependent on the inherent flaws and defects than the saturated one, as the failure pattern doesn't follow a fixed shearing or splitting fracture mode. Overall, the difference of dynamic behaviors between dry and saturated coral rocks are mainly controlled by the coupling weakening and strengthening effects induced by free water. The strengthening effect of water saturation is manifested by making the strength and deformability of coral rock more sensitive to the loading strain rate. • The characteristic physical parameters of coral rocks are measured statistically. • Effects of strain rate and water saturation on mechanical properties are assessed quantitatively. • Failure modes of dry and saturated specimens at different scales are studied. • Underlying mechanisms of water on mechanical properties and failure modes are demonstrated. [ABSTRACT FROM AUTHOR]