Carbon nanotube array as a van der Waals two-dimensional hyperbolic material

We use an ab-initio approach to design and study a novel two-dimensional material - a planar array of carbon nanotubes separated by an optimal distance defined by the van der Waals interaction. We show that the energy spectrum for an array of quasi-metallic nanotubes is described by a strongly anisotropic hyperbolic dispersion and formulate a model low-energy Hamiltonian for its semi-analytical treatment. Periodic-potential-induced lifting of the valley degeneracy for an array of zigzag narrow-gap nanotubes leads to the band gap collapse. In contrast, the band gap is opened in an array of gapless armchair tubes. These unusual spectra, marked by pronounced van Hove singularities in the low-energy density of states, open the opportunity for interesting physical effects and prospective optoelectronic applications

Histopatology of Mystus Nemurus of Liver That Immersed with Curcuma Xanthorrhiza Roxb Extract and Were Infected by Edwardseilla Tarda

This study was conducted over three months in the laboratory of Fish Diseases and Parasites, Faculty of Fisheries and Marine Sciences University of Riau Pekanbaru. The purpose of this research was to determine the structure of (Mystus nemurus) liver that were immersed with Curcuma xanthorrhiza ROXB extract and were infected by Edwardseilla tarda and to find out best dose Curcuma xanthorrhiza ROXB extract for the prevention of Edwardsiella tarda infections. The method used is an experimental method at a dose of treatment and analyzed descriptive. The treatment used is an extract of Curcuma xanthorrhiza ROXB with different concentrations, they were: Kn (Fishes were not receive any treantent), Kp (Fishes were not receive any treatment but were infected with E. tarda), P1 (immersed in curcuma with concentration 0,2 g/l), P2 (immersed in curcuma with concentration 0,4 g/l), P3 (immersed in curcuma with concentration 0,6 g/l) and were infected with E. tarda (0.1 ml of 108 of E. tarda), Fish organ (liver) were processed for histological studied (formalin fixed, alcohol series, 6 sliced and HE Stained). Result indicate that the structure of liver of the treated fish showing abnormality symptoms, such as necrosis, congestion, fatted degeneration and hemorrhage. From these, it can be concluded that immirsion in Curcuma with 0.6 g / l concentration is capable of inhibiting bacterial Edwardsiella tarda

Histopathology of Gill and Brain of Tilapia (Oreochromis Niloticus) That Were Infected with Streptococcus Iniae

This research was conducted on July until Desember 2015 at Parasite and Fish Disease Laboratory, Faculty of Fisheries and Marine Sciences, University of Riau. The aims of this research was to determine a gill and brain tissue changes of Tilapia (O. niloticus) infected by S. iniae with different concentration. This research used experimental method, infected with according to treatment and were analyzed. The treatments applied were intraperitoneal infection by S. iniae with different concentration, they were ; Kn (negative control, were not infected by S. iniae), P1 (infection by S. iniae with concentration 109 CFU/mL), P2 (infected by S. iniae with concentration 107 CFU/mL), P3 (infected by S. iniae with concentration 105 CFU/mL), and than fishes were reared for 7 days. Gill tissue showed hyperplasia, fusion in lamella and haemorrhage, gill tissue condition in P1 and P2 suffered in the same destruction with moderate category, and gill tissue condition in P3 in light category. The brain tissue showed haemorrhage, congestion and necrosis. Damage to the gill and brain tissue of tilapia due to S. iniae infected

Histopathology of Mystus Nemurus Liver That Were Fed with Feed Added with Psidium Guajava and Andrographis Paniculata Ness

This research was conducted on June to August 2014 in the Laboratory of Parasitesand Diseases of Fisheris and Marine Science of Faculty Riau University Pekanbaru. Thepurpose of this research was to determine the structure of (Mystus nemurus) liver that werefed with feed added with Psidium guajava and Andrographis paniculata Ness. The methodused is an experimental using 3 treatments with 3 replicated. The treatment used in thisresearch was Kn (Fishes were not receive any treantent), Kp (Fishes were not receive anytreatment but were infected with A. hydrophila), P1 ( Fishes were fed with feed added with10 g of Psidium guajava and 10 g of Andrographis paniculata Ness and were infected withA. hydrophila (0.1 ml of 108 of A. hydrophila culture), P2 (Fishes were fed with feed addedwith 20 g of Psidium guajava and 20 g of Andrographis paniculata Ness and were infectedwith A. hydrophila (0.1 ml of 108 of A. hydrophila culture), P3 (Fishes were fed with feedadded with 30 g of Psidium guajava and 30 g of Andrographis paniculata Ness and wereinfected with A. hydrophila (0.1 ml of 108 of A. hydrophila culture). Fish organ (liver) wereprocessed for histological studied (formalin fixed, alcohol series, 6 sliced and HE Stained).Result indicate that the structure of liver of the treated fish showing abnormality symptoms,such as necrosis, fatted degeneration and hemorrhage. It can be concluded that feeding offish with 30 g of Psidium guajava and 30 g of Andrographis paniculata Ness is able to treatA. hydrophila infection on Mystus nemurus

Survival Rate of Pangasius Hypopthalmus That Are Immersed in Curcumin (Curcuma Domestica V) and Were Infected by Aeromonas Hydrophila

This research was held in June-November 2015 in Parasites and Fish Diseases Laboratory, Faculty of Fisheries and Marine Science, University of Riau Pekanbaru. This research aimed to determine survival rate of Pangasius hypopthalmus that are immersed in curcumin (Curcuma domestica V) and infected by Aeromonas hydrophila. This research used five treatment such as; Kn (negative control): were not immersed of curcumin and were not infected A. hydrophila, Kp (positive control): were not immersed of curcumin and infected by A. hydrophila), P1: immersed with curcumin 0,5g/L, P2 immersed with curcumin 0,7g/L and P3: immersed with curcumin 0,9 g/L. The fish were immersed with curcumin for two minutes each once a week and they were reared for 28 days. The result showed P1 ( immersion with curcumin solution in a dose of 0,5 g/L) were the best treatment with survival rate of 93,33% and total of leucocytes 16,1167x104 cell/mm3. It was concluded that curcumin can be used for prevention of A. hydrophilla and increase the survival rate of Pangasius hypopthalmus

Cathode Active Material Recycling from Spent Lithium Batteries: A Green (Circular) Approach Based on Deep Eutectic Solvents

The transition to a circular economy vision must handle the increasing request of metals required to satisfy the battery industry; this can be obtained by recycling and feeding back secondary raw materials recovered through proper waste management. Here, a novel and green proof-of-concept was developed, based on deep eutectic solvents (DESs) to fully and easily recover valuable metals from various cathode active materials, including LiMn2O4, LiNi0.5Mn1.5O4, and LiNi0.8Co0.2O2. DES composed of choline chloride and lactic acid could leach Li, Mn, Co, and Ni, achieving efficiency of 100 % under much milder conditions with respect to the previous literature. For the first time, to our best knowledge, a two-step approach was reported in the case of LiNi0.8Co0.2O2 for selective recovery of Li, Co, and Ni with high yield and purity. Furthermore, other cathode components, namely aluminum current collector and binder, were found to be not dissolved by the proposed DES, thus making a simple separation from the active material possible. Finally, this strategy was designed to easily regenerate and reuse the leaching solvents for more than one extraction, thus further boosting process sustainability

An in-situ synchrotron XAS methodology for surface analysis under high temperature, pressure and shear

The complex tribochemical nature of lubricated tribological contacts is inaccessible in real time without altering their initial state. To overcome this issue, a new design of a pin-on-disc tribological apparatus was developed and combined with synchrotron X-ray absorption spectroscopy (XAS). Using the designed apparatus, it is possible to study in situ the transient decomposition reactions of various oil additives on different surfaces under a wide range of realistic operating conditions of contact pressure (1.0–3.0 GPa), temperature (25–120 °C), and sliding speed (30–3000 rpm or 0.15–15 m/s). To test the apparatus, several tribological tests were performed at different shearing times ranging from 2.5 to 60 min. These tests were carried out under helium atmosphere at a temperature of 80  °C, contact pressure of 2.2 GPa, and sliding speed of 50 rpm. The XAS experiments indicate that the zinc dialkyldithiophosphate antiwear additive decomposes in the oil to form a tribofilm on the iron surface at different reaction kinetics from the ones of the thermal film. The tribofilm composition evolves much faster than the one of the thermal film, which confirms that the formation of the tribofilm is a thermally activated process similar to the one of the thermal film but accelerated by shear. Furthermore, the results indicate that the sulfur of the formed film, whether a tribofilm or a thermal film, appears initially in the form of sulfate, with some sulfide, which under heat or shear is reduced into mainly sulfide