Impacts of pollution discharges from Dinh Vu industrial zone on water quality in the Hai Phong coastal area

The hydrodynamic and water quality models (the Delft3D model) were established based on the measured data and the estimated pollution discharges from Dinh Vu industrial zones to Nam Trieu estuary. With seven separate simulation scenarios, the results show that in case of increased wastewater with the control of pollution discharge (water and concentration), the impact of pollution is only limited to a small area around the discharge point. Their influences on water quality in other areas in Nam Trieu estuary are quite small. Meanwhile, in case of environmental risk, a strongly increasing pollution load would cause the significantly increasing pollutant concentration in this area, they have almost exceeded the value in the National Technical Regulation on surface water quality (QCVN 10-MT:2015/BTNMT), such as NH4, COD, and BOD. Dissolved oxygen in the water would also decrease significantly. The spatial influence extends from the discharge point to Nam Trieu estuary, inside Cam, Bach Dang rivers, and Cat Hai coastal area

Local Minimizers of Nonconvex Functions in Banach Spaces via Moreau Envelopes

This paper investigates the preservation of local minimizers and strong minimizers of extended-real-valued lower semicontinuous functions under taking their Moreau envelopes. We address a general setting of Banach spaces, while all the obtained results are new even for functions in finite dimensions. Our main motivation came from applications to numerical methods in nonsmooth optimization dealing with broad classes of nondifferentiable and nonconvex functions. The paper also formulates and discusses some open questions stemming from this study

Variational and Strong Variational Convexity in Infinite-Dimensional Variational Analysis

This paper is devoted to a systematic study and characterizations of the fundamental notions of variational and strong variational convexity for lower semicontinuous functions. While these notions have been quite recently introduced by Rockafellar, the importance of them has been already recognized and documented in finite-dimensional variational analysis and optimization. Here we address general infinite-dimensional settings and derive comprehensive characterizations of both variational and strong variational convexity notions by developing novel techniques, which are essentially different from finite-dimensional counterparts. As a consequence of the obtained characterizations, we establish new quantitative and qualitative relationships between strong variational convexity and tilt stability of local minimizers in appropriate frameworks of Banach spaces

Performance of DASH over Multipath TCP

Recently, dynamic adaptive streaming over HTTP (DASH) is a dominated traffic in Internet. The client requests a suitable representation depending on the current network condition. On the other hand, multipath transmission control protocols emerges as potential data transmission utilizing multiple network paths concurrently. In this paper, we conduct extensively experiments to evaluate the performance of DASH over MPTCP. Four different performance metrics are investigated, i.e., time on high quality, impactful switches, switch frequency, and average bitrate. The results show that the performance of DASH decreases when the paths of MPTCP have different bandwidths

Investment in human capital and labor productivity in Vietnam : the case study on small and medium enterprises

This paper investigates the importance of training in Small and Medium Enterprises (SMEs) in Vietnam as a basis for improving productivity. Current training courses are ineffective, and need to be associated with practical work. Trainers need appropriate experience as well as knowledge of how to organize classes. SME Support Centres are evaluated in terms of trainers and training: findings show that training organization for SMEs should be classified by types of trainees; courses for employees should focus on particular skills; and policies should encourage management skills training as well. Development of new curriculum materials is urgent

Impact of sand mining on sediment transport and morphological change of Hai Phong coastal area

The paper presents the results of simulating the impact of sand mining on sediment transport and morphological change in Hai Phong coastal area based on Delft3D model. Scenario groups are established: Present scenarios without sand mining and simulated scenarios of the present sand mining (assuming 30% sand compared to plan). The scenario groups are calculated in the dry and rainy seasons for main wind directions (NE, SE, SW) in the case of moderate wind and strong wind. The results show that sand mining reduces sediment flow alongshore (2–81%) and seawards (5–83%). Besides, the increase in depth causes morphological change in this area: Rising the deposition rate (5–10 mm/month) at the sand mining locations; decreasing accretion rate and increasing the erosion rate in the neighboring areas of sand mining location

Clinical and Microbiological Features of Pediatric Endopthalmitis After Open Globe Injury in the North of VietNam

BACKGROUND: Pediatric endophthalmitis after open-globe injury had its clinical features, microbiological profile different from those in aldults. In Viet Nam, there was no report on the clinical and microbiological characteristic of pediatric posttraumatic endophthalmitis. Therefore, we conduct this study. AIM: To describe clinical features, ultrasound results, gram stain and culture results of endophthalmitis in pediatric open globe injuries. METHODS: Prospective non-controlled study. Case series of 30 eyes presenting with post-traumatic endophthalmitis between 2015 and 2016 were reviewed. RESULTS: Mean age was 8.03 ± 3.99 years. Metallic and organic etiologies were most common causes for injuries (n = 11). 27 cases had penetrating corneal trauma. Dense opaque vitreous was seen in 25 eyes. Retinal necrosis < 1 quadrant and chorioretinal abscess > 1 quadrant were most common fundus lesions. Dense vitreous opacity on ultrasound was most common (n = 28). Gram stain bacteria positivity was 93.3%, gram-positive were isolated in 63.3%. Vitreous samples were more often positive than aqueous (P = 0,002). CONCLUSION: Posttraumatic endophthalmitis in children is more common in boys aged 6-10 years and most often caused by injury with metallic and organic matter. Culture results were very low. Vitreous samples were more often positive than aqueous. Gram-positive bacteria were the most common causative organism