Carbon dioxide - heavy oil systems: thermodynamics, transport and interfacial stability

Conventional oil recovery leaves behind around 67% of original oil in place for light oils and all of it for heavy oils. The carbon dioxide flooding process is the cheapest among the recovery methods for the next stage. The interest here lies in recovering heavy oil. When CO2 dissolves in oil, it increases the volume of oil, squeezes it out of narrow capillaries and the viscosity of oil drops by up to an order of magnitude. Starting with the available data with and without CO2 in heavy oil, the free volume theory is used to predict these physical properties. Specific volume CO2 in the solution is obtained from the swelling data. The viscosity data show us how to obtain the free volumes of CO2 in oil and hence allow prediction of the diffusivity of CO2. Separately, an analysis of the displacement process has been undertaken in a single cylindrical pore ~ 1 µm in diameter where the disjoining pressure is included and added to the Laplace pressure, besides the correlations obtained earlier. Numerical solutions have been obtained to provide the results: profile shapes, capillary numbers, and the thickness of thin oil film left behind the drive and net mass transfer rates across the interface. Finally, the viscosity of heavy crude is much higher than the viscosity of CO2 because of which the displacement process can be unstable leading to fingering or channeling. Linear stability analysis of the displacement process which is that of immiscible displacement but includes mass transfer has been investigated. We are able to provide results that lead to a stabilizing effect overcomes a large destabilizing effect of the adverse mobility ratio. The results show that in the limit that the solubility of CO2 in oil drops to zero, the above window of instability becomes infinite --Abstract, page iii

Performance of export-oriented small and medium-sized manufacturing enterprises in Viet Nam

The study recommends the formulation of policies that support the development of business linkages and networking, and which promote subcontracting arrangements between small and large enterprises or between domestic firms and foreign investment enterprises. It is also necessary to support and facilitate the direct involvement of SMMEs in exporting or indirectly through large manufacturing enterprises.Export-oriented, SME,SMME, Viet Nam

ICT and financial development: Empirical evidence from ASEAN countries

This paper empirically investigates the impact of Information and Communication Technology (ICT) on financial development proxied by Domestic credit/GDP and Money supply/GDP in ten ASEAN countries over the period 2000-2020. Results from fixed effects for panel data show that ICT stimulates financial development by both proxies. Remarkably, the impact of ICT on financial development proxied by Money supply/GDP is stronger than that proxied by Domestic credit/GDP, implying the important channel of Money supply/GDP through which ICT can stimulate financial development. In addition, other important determinants of financial development are confirmed in the context of ASEAN countries, including economic growth, trade openness, and urbanization. The findings consolidate the utilization of ICT to boost financial development in ASEAN countries

Oral Cancer: The State of the Art of Modern-Day Diagnosis and Treatment

Diagnosing and treating lesions of the mouth and gums is challenging for most clinicians because of the wide variety of disease processes that can present with similar appearing lesions and the fact that most clinicians receive inadequate training in mouth diseases. Oral cancer, a common lesion in oral cavity, is not correctly diagnosing a clinical picture of an early squamous cell carcinoma. The prevalence of oral cancer continues to rise worldwide, related to the increase in consumption of tobacco, alcohol and other carcinogenic products. However, there has also been a significant reduction in mortality due to increasing awareness, early diagnosis and advances in treatments. This chapter is an attempt to provide a comprehensive update encompassing the spectrum of etiologic/risk factors, current clinical diagnostic tools, management philosophies, and molecular biomarkers and progression indicators of oral cancer

Overview of the VLSP 2022 -- Abmusu Shared Task: A Data Challenge for Vietnamese Abstractive Multi-document Summarization

This paper reports the overview of the VLSP 2022 - Vietnamese abstractive multi-document summarization (Abmusu) shared task for Vietnamese News. This task is hosted at the 9$^{th}$ annual workshop on Vietnamese Language and Speech Processing (VLSP 2022). The goal of Abmusu shared task is to develop summarization systems that could create abstractive summaries automatically for a set of documents on a topic. The model input is multiple news documents on the same topic, and the corresponding output is a related abstractive summary. In the scope of Abmusu shared task, we only focus on Vietnamese news summarization and build a human-annotated dataset of 1,839 documents in 600 clusters, collected from Vietnamese news in 8 categories. Participated models are evaluated and ranked in terms of \texttt{ROUGE2-F1} score, the most typical evaluation metric for document summarization problem.Comment: VLSP 202

ẢNH HƯỞNG CỦA NGUỒN THỨC ĂN ĐẾN SỰ SINH TRƯỞNG CỦA GIUN ĐẤT Amynthas rodericensis (Grube, 1879) TRONG ĐIỀU KIỆN NUÔI THỬ NGHIỆM

Amynthas rodericensis is a common earthworm species in Vietnam. The feeding material and substrate affect the growth and reproduction of earthworms. The individual size, total number, weight, and gain weight of earthworms under laboratory conditions were investigated. The experiment was designed with four treatments (100% pig manure; 75% pig manure and 25% substrate; 50% pig manure and 50% substrate; 25% pig manure and 75% substrate) with six replicates in a completely randomized design; the experiments lasted ten weeks. The maximum growth and reproduction of A. rodericensis are observed with 75% pig manure and 25% substrate.Amynthas rodericensis là loài giun đất phổ biến ở Việt Nam. Nguồn thức ăn và cơ chất là những yếu tố ảnh hưởng đến sự sinh trưởng của giun đất nói chung và A. rodericensis nói riêng. Các yếu tố ảnh hưởng đến sự sinh trưởng bao gồm kích thước, khối lượng cơ thể, số lượng cá thể và tăng trọng cơ thể. Thí nghiệm có bốn nghiệm thức tương ứng với các tỷ lệ phối trộn phân lợn và chất nền khác nhau (NT1: 100% phân lợn; NT2: 75% phân lợn và 25% chất nền; NT3: 50% phân lợn và 50% chất nền; NT4: 25% phân lợn và 75% chất nền); mỗi nghiệm thức lặp lại sáu lần, bố trí theo phương pháp ngẫu nhiên hoàn toàn và được theo dõi đến 10 tuần. Kết quả cho thấy tỷ lệ phối trộn phân lợn với chất nền có ảnh hưởng khác nhau đến khả năng sinh trưởng của giun đất A. rodericensis. Sự sinh trưởng của giun cao nhất ở nghiệm thức NT2 (75% phân lợn và 25% chất nền)

Disinfection performance of an ultraviolet lamp: a CFD investigation

Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls

User Selection Approaches to Mitigate the Straggler Effect for Federated Learning on Cell-Free Massive MIMO Networks

This work proposes UE selection approaches to mitigate the straggler effect for federated learning (FL) on cell-free massive multiple-input multiple-output networks. To show how these approaches work, we consider a general FL framework with UE sampling, and aim to minimize the FL training time in this framework. Here, training updates are (S1) broadcast to all the selected UEs from a central server, (S2) computed at the UEs sampled from the selected UE set, and (S3) sent back to the central server. The first approach mitigates the straggler effect in both Steps (S1) and (S3), while the second approach only Step (S3). Two optimization problems are then formulated to jointly optimize UE selection, transmit power and data rate. These mixed-integer mixed-timescale stochastic nonconvex problems capture the complex interactions among the training time, the straggler effect, and UE selection. By employing the online successive convex approximation approach, we develop a novel algorithm to solve the formulated problems with proven convergence to the neighbourhood of their stationary points. Numerical results confirm that our UE selection designs significantly reduce the training time over baseline approaches, especially in the networks that experience serious straggler effects due to the moderately low density of access points.Comment: submitted for peer review