151 research outputs found
STUDY ON APPLICABILITY OF THE CONTACT OXIDATION PROCESS IN REMOVAL OF ORGANIC POLLUTANTS FROM TEXTILE WASTEWATER
Joint Research on Environmental Science and Technology for the Eart
Estimation of forest Carbon Stocks in Ba Be National Park, Bac Kan province, Vietnam
Climate change and an increase in the greenhouse effect are a matter of global concern. One of reasons for this phenomenon is the increase in greenhouse gases, especially CO2. Therefore, the authors investigated CO2 absorption from forests of 45 plots in Ba Be National Park, characterized by 3 forest states as rich, medium and poor forest, rehabilitated forest after exploitation to estimate carbon sequestration of the forest. In which, the carbon stock of rich forest reaches 273.17 tones/ha, the medium forest is 136.23 tones/ha and the poor forest, rehabilitated forest is 42.06 tones/ha. With a forest growth rate of 1.8% per year, the carbon sequestration in Ba Be National Park for 3 forest states is about 16,499 tones per year. This will contribute to improve environmental quality, reducing greenhouse gas emissions and creating a scientific basis for managers to develop a payment mechanism of forest carbon sequestration services
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·mLâ1) 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·mLâ1 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
Nitrite metabolism of several bacterial strains isolated from abattoir and swine wastewater after biogas treatment
In nitrogen treatment with biological methods, nitrite metabolism is an intermediate process that facilitates other processes involving different bacteria strains. In this study, we isolated two nitrite-oxidising bacteria strains from abattoir wastewater and wastewater from biogas tanks of an industrial pig farm in Ha Tinh province. The bacteria strains grow, develop, and metabolise nitrite at pH 6â8 and 30â37 °C. The samples with the nitrite concentration up to 750 mg·Lâ1 were oxidised within four days of incubation, and the nitrite metabolism rate was proportional to the concentration of nitrite tested. Under severe conditions (salinity up to 3% NaCl, a low dissolved oxygen level of 0.1 mg·Lâ1), the two isolated bacterial strains exhibited their effective growth and nitrite metabolism capacity. The results enrich the database of nitrite-oxidising bacteria and are prospective in wastewater treatment
NeCo@ALQAC 2023: Legal Domain Knowledge Acquisition for Low-Resource Languages through Data Enrichment
In recent years, natural language processing has gained significant
popularity in various sectors, including the legal domain. This paper presents
NeCo Team's solutions to the Vietnamese text processing tasks provided in the
Automated Legal Question Answering Competition 2023 (ALQAC 2023), focusing on
legal domain knowledge acquisition for low-resource languages through data
enrichment. Our methods for the legal document retrieval task employ a
combination of similarity ranking and deep learning models, while for the
second task, which requires extracting an answer from a relevant legal article
in response to a question, we propose a range of adaptive techniques to handle
different question types. Our approaches achieve outstanding results on both
tasks of the competition, demonstrating the potential benefits and
effectiveness of question answering systems in the legal field, particularly
for low-resource languages.Comment: ISAILD@KSE 202
Pulse-width modulation direct torque control induction motor drive with Kalman filter
The paper deals with application of Kalman filter in induction motor drive using pulse-width modulation direct torque control (PWM-DTC). In the ïŹrst part, the conventional PWM-DTC drive is described and Kalman ïŹlter is utilized to filter components of stator current vector those are assumed to be disturbed by white noise. The second part contains simulation results that are obtained in different cases of load torque, process and measurement noise covariances. The integral time absolute error (ITAE) performance index, undershoot, ripple of important quantities are used to compare the conventional drive structure and proposed drive structure with Kalman filter. The simulation results confirm the expected dynamic response of the proposed structure
A Large-Scale Study of a Sleep Tracking and Improving Device with Closed-loop and Personalized Real-time Acoustic Stimulation
Various intervention therapies ranging from pharmaceutical to hi-tech
tailored solutions have been available to treat difficulty in falling asleep
commonly caused by insomnia in modern life. However, current techniques largely
remain ill-suited, ineffective, and unreliable due to their lack of precise
real-time sleep tracking, in-time feedback on the therapies, an ability to keep
people asleep during the night, and a large-scale effectiveness evaluation.
Here, we introduce a novel sleep aid system, called Earable, that can
continuously sense multiple head-based physiological signals and simultaneously
enable closed-loop auditory stimulation to entrain brain activities in time for
effective sleep promotion. We develop the system in a lightweight, comfortable,
and user-friendly headband with a comprehensive set of algorithms and dedicated
own-designed audio stimuli. We conducted multiple protocols from 883 sleep
studies on 377 subjects (241 women, 119 men) wearing either a gold-standard
device (PSG), Earable, or both concurrently. We demonstrate that our system
achieves (1) a strong correlation (0.89 +/- 0.03) between the physiological
signals acquired by Earable and those from the gold-standard PSG, (2) an 87.8
+/- 5.3% agreement on sleep scoring using our automatic real-time sleep staging
algorithm with the consensus scored by three sleep technicians, and (3) a
successful non-pharmacological stimulation alternative to effectively shorten
the duration of sleep falling by 24.1 +/- 0.1 minutes. These results show that
the efficacy of Earable exceeds existing techniques in intentions to promote
fast falling asleep, track sleep state accurately, and achieve high social
acceptance for real-time closed-loop personalized neuromodulation-based home
sleep care.Comment: 33 pages, 8 figure
INFLUENCE OF CULTIVATION OF CHLORELLA VULGARIS ON MICROORGANISMS IN SEAFOOD WASTEWATER
Microalgae cultivation in wastewater for many purposes has been investigated recently decade ago. In this study, Chlorella vulgaris was chosen to culture for examination of its influences on microorganisms of seafood wastewater in particular aerobic bacteria, Coliform and E. coli. The microalgae cultivation was realized in Erlenmeyer flasks containing seafood wastewater medium. Another was also grown in original medium called Sueoka medium for control. All experiments were set up until almost all Chlorella vulgaris decanted or flocculated in the bottom of flasks. The changes of bacteria counts including aerobic bacteria, Coliform and E. coli were measured to evaluate the impact of cultivation of Chlorella vulgaris on them in this sewage. Otherwise, the growth of microalgae has been also recorded for evaluating the effect of a new medium on metabolism of Chlorella vulgaris. The results showed that the bacteria counts were significantly reduced after day 3 of microalgae culture. These results have been calculated the efficiency of aerobic bacteria, Coliform and E. coli elimination out of wastewater medium represented approximately 70%, 81% and 90% respectively. These eliminations provided evidences of difficult metabolism of bacteria under the presence of microalgae as like as Chlorella vulgaris. In other words, the symbiosis of microalgae and bacteria in sewage could prevent the raising of bacteria counts
Solving the Traveling Salesman Problem with Ant Colony Optimization: A Revisit and New Efficient Algorithms
Ant colony optimization (ACO) techniques are known to be efficient for combinatorial optimization. The traveling salesman problem (TSP) is the benchmark used for testing new combinatoric optimization algorithms. This paper revisits the application of ACO techniques to the TSP and discuss some general aspects of ACO that have been previously overlooked. In fact, it is observed that the solution length does not reflect exactly the quality of a particular edge belong to the solution, but it is only used for relatively evaluating whether the edge is good or bad in the process of reinforcement learning. Based on this observation, we propose two algorithmsâ Smoothed Max-Min Ant System and Three-Level Ant Systemâ which not only can be easily implemented but also provide better performance, as compared to the well-known Max-Min Ant System. The performance is evaluated by numerical simulation using benchmark datasets
Comparative analysis of root transcriptomes from two contrasting drought-responsive Williams 82 and DT2008 soybean cultivars under normal and dehydration conditions
The economically important DT2008 and the model Williams 82 (W82) soybean cultivars were reported to have differential drought-tolerant degree to dehydration and drought, which was associated with root trait. Here, we used 66K Affymetrix Soybean Array GeneChip to compare the root transcriptomes of DT2008 and W82 seedlings under normal, as well as mild (2h treatment) and severe (10h treatment) dehydration conditions. Out of the 38172 soybean genes annotated with high confidence, 822 (2.15%) and 632 (1.66%) genes showed altered expression by dehydration in W82 and DT2008 roots, respectively, suggesting that a larger machinery is required to be activated in the drought-sensitive W82 cultivar to cope with the stress. We also observed that long-term dehydration period induced expression change of more genes in soybean roots than the short-term one, independently of the genotypes. Furthermore, our data suggest that the higher drought tolerability of DT2008 might be attributed to the higher number of genes induced in DT2008 roots than in W82 roots by early dehydration, and to the expression changes of more genes triggered by short-term dehydration than those by prolonged dehydration in DT2008 roots vs. W82 roots. Differentially expressed genes (DEGs) that could be predicted to have a known function were further analyzed to gain a basic understanding on how soybean plants respond to dehydration for their survival. The higher drought tolerability of DT2008 vs. W82 might be attributed to differential expression in genes encoding osmoprotectant biosynthesis-, detoxification- or cell wall-related proteins, kinases, transcription factors and phosphatase 2C proteins. This research allowed us to identify genetic components that contribute to the improved drought tolerance of DT2008, as well as provide a useful genetic resource for in-depth functional analyses that ultimately leads to development of soybean cultivars with improved tolerance to drought
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