Simulating of Biofuel Production from Rice Husks

In the context of energy crisis and environmental damage due to rapid depletion and overuse of fossil fuel, alternative renewable energy resources such as biomass have been being significantly studied recently. In Southeast Asia countries like Malaysia, one of the abundant biomass feed stocks is rice husk which is a residue from rice production process. Rice husk can be transformed into gasoline through a series of fast pyrolysis and catalytic cracking processes. However, there is limited work on simulating the whole process. The objective of this project is to develop a mathematical simulation for the production of gasoline from rice husk using MATLAB. From the developed model, parametric studies have been conducted to identify the operating conditions which give the highest yield of product. The mathematic model was based on kinetic equations for the two main processes together with basic mass and energy balance for other subprocesses in the flowsheet. As a result, the model has shown that from 1000kg of rice husk, 191 liters of gasoline would be obtained. Within the studied range, the operating conditions at temperature of 783K and residence time of 5s for pyrolysis and at 723K in 1.25h for catalytic cracking are proposed to get the highest gasoline yield. The developed model can be considered as a basis for further research on simulating the production process of biofuel from rice husk

Simulating of Biofuel Production from Rice Husks

In the context of energy crisis and environmental damage due to rapid depletion and overuse of fossil fuel, alternative renewable energy resources such as biomass have been being significantly studied recently. In Southeast Asia countries like Malaysia, one of the abundant biomass feed stocks is rice husk which is a residue from rice production process. Rice husk can be transformed into gasoline through a series of fast pyrolysis and catalytic cracking processes. However, there is limited work on simulating the whole process. The objective of this project is to develop a mathematical simulation for the production of gasoline from rice husk using MATLAB. From the developed model, parametric studies have been conducted to identify the operating conditions which give the highest yield of product. The mathematic model was based on kinetic equations for the two main processes together with basic mass and energy balance for other subprocesses in the flowsheet. As a result, the model has shown that from 1000kg of rice husk, 191 liters of gasoline would be obtained. Within the studied range, the operating conditions at temperature of 783K and residence time of 5s for pyrolysis and at 723K in 1.25h for catalytic cracking are proposed to get the highest gasoline yield. The developed model can be considered as a basis for further research on simulating the production process of biofuel from rice husk

USING RUBRIC TO ASSESS PRIMARY SCHOOL STUDENTS' COMPETENCE IN TEACHING SCIENCE IN VIETNAM

Vietnam is in the early stages of implementing the reform of the curriculum and textbooks. Vietnam's general education is changing strongly from content-based teaching to competence-building teaching [1]. That change has been implemented by researchers and teachers in all elements of the teaching process, including testing and evaluation. Evaluation of educational outcomes needs to shift from testing memorization to assessing the ability to apply knowledge to solve practical problems, attaching importance to both assessment of learning outcomes and assessment in the learning process. In this situation, testing and assessment in teaching Science in primary schools are also interesting to many teachers, and assessment of scientific competence in teaching this subject is considered an important factor contributing to improving the quality of Science and the quality of subject teaching in the direction of developing students' ability. The article mentions some theoretical foundations and the actual situation of using Rubric in assessing the scientific competence of students in grades 4 and 5 when teachers teach Science, thereby proposing some measures to improve the effectiveness of assessment in teaching this subject.  Article visualizations

Assessment of blasted excavation inaccuracy at tunnel face and influences on tunnelling effectiveness

Blasting has been the most effective solution for tunnel excavation in hard rock. The accuracy of the blasting works is demonstrated by the similarity between the design and the actual excavation boundary. Hence, the overbreak and underbreak of the tunnel boundary are used to evaluate the tunnel excavation. Widely applied for rock tunnelling, New Austrian Tunnelling Method (NATM) has been used for almost all highway tunnels in Vietnam. The assessment of the previous projects is essential since it provides learnt experiences and enriches the knowledge to handle the tunnelling technology. With this aim, the paper studied the case of a 500m NATM tunnel located on the N01 national highway in Central Vietnam. The practical excavation zone was examined, and the overbreak and underbreak of the tunnel boundary during the excavation by explosive was investigated. The dependences of the overbreak and underbreak on the geological and technical conditions were indicated. The tunnelling effectiveness was then assessed through the additional materials and works for the face correction activities

Assessment of blasted excavation inaccuracy at tunnel face and influences on tunnelling effectiveness

Blasting has been the most effective solution for tunnel excavation in hard rock. The accuracy of the blasting works is demonstrated by the similarity between the design and the actual excavation boundary. Hence, the overbreak and underbreak of the tunnel boundary are used to evaluate the tunnel excavation. Widely applied for rock tunnelling, New Austrian Tunnelling Method (NATM) has been used for almost all highway tunnels in Vietnam. The assessment of the previous projects is essential since it provides learnt experiences and enriches the knowledge to handle the tunnelling technology. With this aim, the paper studied the case of a 500m NATM tunnel located on the N01 national highway in Central Vietnam. The practical excavation zone was examined, and the overbreak and underbreak of the tunnel boundary during the excavation by explosive was investigated. The dependences of the overbreak and underbreak on the geological and technical conditions were indicated. The tunnelling effectiveness was then assessed through the additional materials and works for the face correction activities

IDENTIFICATION AND CHARACTERIZATION OF A PURPLE NONSULFUR BACTERIUM ISOLATED FROM COASTAL AREA OF HAI PHONG FOR USING IN PRODUCTION OF UNSATURATED FATTY ACID (OMEGA 6, 7, 9)

Purple nonsulfur bacteria are a group that has so much biotechnological applications, particularly in producing of functional food rich with unsaturated fatty acids. A purple nonsulfur bacterium (named HPB.6) was chosen based on its strong growth, high lipid and synthesis of unsaturated fatty acid (omega 6,7,9). Studying on basic biological characteristics showed that the cells of HPB.6 were observed as ovoid-rod shape, none motility, Gram negative staining. The diameter of single bacterium was about 0.8-1.0 µm. The cells divide by binary fission and had bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0% (optimum 3%), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 4.0 - 5.2 mM. Based on morphological, physiological properties and 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum

CFD model-supported design of monodisperse co-current spray dryers

[EN] In this study the operation of spray drying chambers fitted by the multi-stream monodisperse atomizer was simulated by the previously developed CFD model of skim milk spray drying. A series of CFD simulations of skim milk monodisperse spray drying were performed. The influence of different nozzle positions, initial droplet diameters (180 μm and 167 μm) and the way of air introduction (vertical or swirling with 30° or 60° angle) on the drying process were checked. Parameters like drying air and particle residence time, wall deposition, inter-particle collisions, protein thermal deactivation, air velocity and temperature profiles were compared for each case.The research leading to these results has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement n°613732 – project ENTHALPY.Jaskulski, M.; Tran, TTH.; Tsotsas, E. (2018). CFD model-supported design of monodisperse co-current spray dryers. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 213-220. https://doi.org/10.4995/IDS2018.2018.7274OCS21322

Factors contributing to household-resilience capacity to farming risks: Case study of clam farming in Thai Binh province, Vietnam

Despite coastal endowment is a unique opportunity for coastal farmers it may be embedded with some risks. Vietnam was ranked 18th in world risk index in 2015 with the vulnerability index of 50.87% (Garschagen, Hagenlocher et al. 2016). In this context, Vietnamese clam farmers have been experiencing increased difficulties. This research focuses on clam production in Thai Binh province which has the largest clam area in northern and northern central coastal Vietnam. The central question of the research was “which factors contributing to farmer’s resilience to clam farming risks”. Results of the research indicated that there are several factors, which altogether explained 66% of variance of resilience among the households, formed three groups including (1) farmer’s ability in gaining experiences from failures and harnessing new opportunities; (2) farmer’s perception toward clam farming risks and its impacts; (3) farmer’s confidence about financial capacity and incomes from diversifying activities which can be used to invest in clam farming. From these research results, several support strategies have been suggested to enhance this capacity of the clam farmers, in order to minimize the losses while maximizing the benefit when people seek for sustainable livelihood

Ammonia oxidation capacity of bacillus bacteria in swine wastewater after biogas treatment

Nitrogen removal with biological methods plays a crucial role in wastewater treatment technology. The treatment begins with the oxidation of ammonia to nitrite to facilitate the subsequent nitrification and denitrification. Various strains of ammonia-oxidising bacteria have been reported. In this study, we use three Bacillus bacteria isolated from swine wastewater to oxidise ammonia. Different initial densities (103, 104, 105, and 106 CFU·mL–1) of each strain were examined. The results show that the combination of all the bacteria at a ratio of 1:1:1 and a density of 105 CFU·mL–1 exhibits the most effect. The findings contribute to the diversity of ammonia-oxidising bacterial species and pose a great potential for applying these strains in wastewater treatment

Effects of oil and grape seed tannin extract on intakes, digestibility, milk yield and composition of Saanen goats

An experiment was conducted as a 4×4 Latin square design using 4 lactating Saanen goats, 19 months old and 47.9±1.04 kg of body weight, to evaluate the effect of oil and grape seed tannin extract (GSTE) supplementation on feed intake, digestibility, milk yield and milk composition. Each experimental period lasted for 21 days including 16 days for adjustment and 5 days for sampling. Goats were fed a control diet (Ctrl) consisting of 60% concentrate and 40% fresh Para grass (dry matter, DM, basis) while other 3 treatments were supplementation of 2.5% soybean oil (SO); 2.5% soybean oil + tuna fish oil at 3:2 w:w (SFO); 2.5% soybean oil + tuna fish oil at 3:2 w:w + 0.8% GSTE (OCT). The results showed that oil and GSTE did not affect feed intake, digestibility, milk yield and composition of goats (P > 0.05). However, digestibility of EE was higher (P < 0.05) in SFO and OCT diets (85.4% and 84.7%, respectively) compared with Ctrl (76.2%). Combined data suggested that feeding 2.5% oil blend with or without 0.8% GSTE increased EE digestibility in goats without affecting intake, animal performance and milk composition