Linear Approximation and Asymptotic Expansion of Solutions for a Nonlinear Carrier Wave Equation in an Annular Membrane with Robin-Dirichlet Conditions

This paper is devoted to the study of a nonlinear Carrier wave equation in an annular membrane associated with Robin-Dirichlet conditions. Existence and uniqueness of a weak solution are proved by using the linearization method for nonlinear terms combined with the Faedo-Galerkin method and the weak compact method. Furthermore, an asymptotic expansion of a weak solution of high order in a small parameter is established

Pellet feed improvements through vitamin c supplementation for snakehead, channa striata (Bloch 1793), culture

Vitamin C, or ascorbic acid (AA), is important in growth and physiological functions of fish. Six soybean meal-based (SBM) diets containing 0, 125, 250, 500, 1000 and 2000 mg.kg-1 of AA were fed to snakehead, Channa striata (Bloch 1793) (initial weight 6.63 + 0.16 g) for 8 weeks in the laboratory. Survival of snakehead in the 250 and 500 mg.kg-1 treatments was significantly higher (P \u3c 0.05) than the control, but not in the other treatments. Final weight and specific growth rate (SGR) of fish in all the AA-supplemented diet treatments were significantly higher (P \u3c 0.05) than the control. Feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER) also differed significantly, but not in a clearly dose-dependent manner. The requirement of AA for snakehead was calculated to be 277 mg.kg-1. No vertebral anomalies were observed. Erythrocyte count was significantly (P \u3c 0.05) higher at 1000 and 2000 mg.kg-1 than at 0 and 125 mg.kg-1. Fish in 250 mg.kg-1 had significantly (P \u3c 0.05) higher leukocyte count than those in 0, 1000, and 2000 mg.kg-1. A bacterial challenge test with Aeromonas hydrophila revealed that 500 and 1000 mg.kg-1 had the lowest cumulative mortality. In an on-farm trial, SBM-based and commercial diets augmented with 0, 500, 750, or 1000 mg.kg-1 AA were fed to C. striata for 23 weeks. All AA-supplemented SBM-based diets provided significantly (P \u3c 0.05) higher final weights and overall yield than did all the AA-supplemented commercial diets. Maximum survival (85.3 %), final fish weight (573.5 g), yield (293.3 kg.hapa-1) and profit (0.38 USD.kg fish-1), as well as minimum FCR (1.16), production cost (1.12 USD.kg fish-1) and feed cost (0.98 USD.kg fish-1) were obtained with the 500 mg.kg-1 SBM diet

Mineralogical Characterization of Di Linh Bentonite, Vietnam : A Methodological Approach of X-ray Diffraction and Transmission Electron Microscopy

Vietnam has decided to establish nuclear power as further energy option. In order to develop a Vietnamese reference bentonite as potential barrier in a final repository for high radioactive waste, a detailed mineralogical investigation of Di Linh bentonite (Lam Dong province), lacustrine clay, was carried out by different methods especially transmission electron microscopy (TEM) linked with energy-dispersive X-ray (EDX). From a sample homogenized from 5 tones of the bentonite, mineral formulae of clay particles was calculated The calculation also focuses on randomly interstratifications of two and three members. The fraction <2 μm of Di Linh bentonite is composed mainly by montmorillonite (Ca0.06Mg0.03Na0.09K0.03Al1.39Fe0.25Mg0.26(OH)2 Si3.96Al0.04O10) and regular ordering (R1) illite-smectite interstratifications with K- and charge-deficiency (Ca0.04Mg0.07Na0.18K0.16Al1.76Fe0.08Mg0.16(OH)2Si3.62Al0.38O10). Additionally, Fe-poor kaolinite-smectite-vermiculite interstratifications and trace of Fe-rich chloritesmectite- vermiculite interstatifications were identified. TEM-investigations showed analytical proofs of the sedimentary character of smectite formation in the Di Linh deposit. Parent muscovite was weathered in several steps in two different environments: (i) K-leaching and layer-wise alteration into kaolinite; (ii) further edge- controlled alteration of mica into lathlike montmorillonite particles under dissolution of kaolinite layers from former kaolinite-mica intergrowths. Mineralogical composition of the Di Linh bentonite with mainly montmorillonite and illite-rich illite-smectite interstratifications shows that the Di Linh bentonite can be a suitable barrier candidate in final repositories.Godkänd; 2014; 20150212 (svek

Use of TEM-EDX for structural formula identification of clay minerals : a case study of Di Linh bentonite, Vietnam

Transmission electron microscopy linked with energy-dispersive X-ray spectroscopy (TEM-EDX) was applied to characterize mineralogical signals ofweathering processes in the Di Linh bentonite deposit (Vietnam) and to visualize the effects of Na activation on the smectitic phases. Modelling of X ray diffraction patterns (oriented mount) was applied in order to refine the computed structural formula. X-ray diffraction, X-ray fluorescence and Fouriertransform infrared spectroscopy (FT-IR) methods were also applied to verify the TEM-EDX results. An Excel-based routine has been developed in this research to allow fast computation of structural formulae and classification of the investigated clay particles. This routine supports the acquirement of 100 300 TEM-EDX analyses as a representative set of individual particles for each sample. The Excel-based routine involves end members of different clay mineral groups and interstratifications with two or three members (e.g. illite smectite interstratifications – IS-ml; dioctahedral vermiculite–smectite interstratifications – diVS-ml; and kaolinite–montmorillonite–dioctahedral vermiculite interstratifications – KSV-ml). The routine is now freely available. According to the identification procedure, the &lt;2 mm fraction of the Di Linh bentonite (Vietnam) is composed mainly of K- and charge-deficient illite smectite interstratifications (or diVS-ml): montmorillonite-rich randomly ordered (R0) type and illite-rich regularly ordered (R1) type. Additionally, Fe-poor KSV-ml was identified.Industrial Na activation of the Di Linh bentonite resulted in an increase of theR1 diVS-ml portion and dissolution of a large part of the smectite-rich phases.The TEM-EDX approach also gave analytical proof of a sedimentary processfor Di Linh smectite. The parent muscovite was altered in two different environments: (i) K-leaching and layer-wise alteration into kaolinite (weathering), and (ii) further edge-controlled alteration of mica into lath-like montmorillonite particles associated with a dissolution of kaolinite layers from the former kaolinite–mica intergrowths by heat impact (basalt flow).Validerad;2019;Nivå 2;2019-02-06 (johcin)</p

Technical manual: Rice straw management towards circular economy and low emission in the Mekong Delta

The document “Technical manual: Rice straw management towards circular economy and low emission in the Mekong Delta” introduces readers to the characteristics of rice straw, the current status of its treatment, and the management process for using rice straw in a circular way to reduce GHG emissions in rice production. This manual will be a handbook for farmers, extension officers, cooperatives, and others who are interested in rice production that is associated with circular greenhouse gas emission reduction