Planckian Scattering Beyond the Eikonal Approximation in the Functional Approach

In the framework of functional integration the non-leading terms to leading eikonal behavior of the Planckian-energy scattering amplitude are calculated by the straight-line path approximation. We show that the allowance for the first-order correction terms leads to the appearance of retardation effect. The singular character of the correction terms at short distances is also noted, and they may be lead ultimately to the appearance of non-eikonal contributions to the scattering amplitudes.Comment: 15 pages, no figure

EFFECT OF ORGANIC LOADING RATE ON SIMULTANEOUS REMOVAL OF NITROGEN AND PHOSPHORUS FROM AQUATIC PRODUCT PROCESSING WASTEWATER BY ADVANCED A2/O – BAF SYSTEM

Combined system of Anaerobic/Anoxic/Oxic reactor with Biological Aerated Filter (A2/O – BAF) is used to enhance simultaneous removal of nitrogen and phosphorus on aquatic product processing wastewater treatment. A2/O reactor was operated with short solids retention time employed mainly for removal of organic matter and phosphorus together with denitrification and BAF with long solids retention time employed mainly for nitrification. The model of combined A2/O – BAF system made from polyacrylic with the capacity of 49.5 liters was operated with hydraulic retention time decreased from 19.2 to 9.6 hours and organic loading rates increased from 0.50 to 1.0 kgCOD/m3/day.  The results showed that the model not only treated organic matter well but also removed nearly completely both nitrogen and phosphorus. For loading rate of 0.75 kgCOD/m3/day, treatment efficiencies of COD, NH4+-N, TN, TP of the model were the highest as 91.02, 96.82, 84.08, 86.66  %, respectively and output values of these parameters were within the limits of QCVN 11:2008/BTNMT, column A

Selection of suitable fragment from rbcL gene for DNA barcode analysis of family Halymeniaceae, Rhodophyta

Among the members of Halymeniaceae family, Grateloupia sensu lato occupies the largest composition in species. Classification based on morphological traits is difficult due to the highly variable terete to blade-like thalli among the members of this genus that usually leads to misidentification. Molecular systematics has been applied to classify Grateloupia sensu lato so that the taxonomists acquire a better understanding of the species diversity in general. The plastid gene encoding the large subunit of ribulose-1,5-bisphosphate-carboxylase-oxygenase (rbcL) was the focus of numerous marine algal studies concerning phylogeny and molecular evolution. However, using the full length of rbcL showed disadvantages such as cost and time consuming due to two times of sequencing and two times of PCR. In the present study, the shorter sequence, fragment 773 bp at 5’ end and fragment 579 bp at 3’ end of rbcL were applied and compared for the phylogenetic analysis of Halymeniaceae members. The results indicated there are no differences of topological phylogenetic trees, species resolution within genus and genus resolution within the family between fragment 773 bp at 5’ and the full length of rbcL. Therefore, we conclude that fragment 773 bp at 5’ should be used as DNA barcodes for the Halymeniaceae to reduce the cost and time during phylogenetic analysis. Two taxa Grateloupia newly collected in Vietnam were grouped to the known Phyllymenia, a new genus in Vietnam

Modeling of milling forces in facing process of aluminum alloy AL7075 using the square inserts

Cutting forces play very important in designing the tool machine, cutting tool, and in optimization of machining processes. Modeling and prediction of cutting forces by theoretical methods are quite difficult, so, this study was focused on modeling the cutting force in face milling process using combination of theoretical and experimental methods. This study was performed to model the milling forces (MFs) and determine the milling force coefficients (MFCs) in the face milling process of aluminum alloy Al7075 using square inserts. From theoretical and experimental methods, the relationship of average milling forces (AMFs) and feed per flute (ft) were determined as the linear regression. Using experimental data, the linear regressions of AMFs and feed per flute were determined with high values of determination coefficients (larger than 95 %). MFCs were determined including shear and edge MFCs (tangential shear MFC (Ktc) of 538.127 N/mm2, radial shear MFC (Krc) of 185.967 N/mm2, axial shear MFC (Kac) of -691.297 N/mm2, tangential edge MFC (Kte) of 11.253 N/mm, radial edge MFC (Kre) of 6.991 N/mm, and axial edge MFC (Kae) of –32.971 N/mm. The MF models were successfully verified by comparing the measured and predicted MFs in face milling process of Al7075. The tendency and shape of predicted MFs were quite close to the measured ones. The differences between the predicted and the measured MFs can be due to the several reasons such as the influence of vibrations, the influence of cutting heat, etc., and these are also the limitations of this study. The modeling and prediction methods of this study can be used to model and predict the cutting forces in face milling of other milling types and other pairs of cutting tool and workpiece material as wel

Analysis of rDNA reveals a high genetic diversity of Halophila major in the Wallacea region

The genus Halophila shows the highest species diversity within the seagrass genera. Southeast Asian countries where several boundary lines exist were considered as the origin of seagrasses. We hypothesize that the boundary lines, such as Wallace’s and Lydekker’s Lines, may act as marine geographic barriers to the population structure of Halophila major. Seagrass samples were collected at three islands in Vietnamese waters and analyzed by the molecular maker ITS. These sequences were compared with published ITS sequences from seagrasses collected in the whole region of interest. In this study, we reveal the haplotype and nucleotide diversity, linking population genetics, phylogeography, phylogenetics and estimation of relative divergence times of H. major and other members of the Halophila genus. The morphological characters show variation. The results of the ITS marker analysis reveal smaller groups of H. major from Myanmar, Shoalwater Bay (Australia) and Okinawa (Japan) with high supporting values. The remaining groups including Sri Lanka, Viet Nam, the Philippines, Thailand, Malaysia, Indonesia, Two Peoples Bay (Australia) and Tokushima (Japan) showed low supporting values. The Wallacea region shows the highest haplotype and also nucleotide diversity. Non-significant differences were found among regions, but significant differences were presented among populations. The relative divergence times between some members of section Halophila were estimated 2.15–6.64 Mya

The role of orographic effects on occurrence of the heavy rainfall event over Central Vietnam in November 1999

In this study, the WRF model is used to investigate the role of Central Vietnam terrain on occurrence of the heavy rainfall event in November 1999 over Central Vietnam. Two model experiments with and without terrain were performed to examine the orographic blocking effects during the event. In the terrain experiment, the results from a three-day simulation show that the model reasonably well captures northeast monsoon circulation, tropical cyclones and the occurrence of heavy rainfall in Central Vietnam. The topography causes a high pressure anomaly intensifying northeast monsoon. When the terrain is removed, the three-day accumulated rainfall decreases approximately 75% in comparison with that in the terrain experiment. The terrain blocking and lifting effects in strong wind and moisture laden conditions combined with convergence circulation over open ocean are the main factors for occurrence of the heavy rainfall event

Applying convolutional neural networks for limited-memory application

Currently, convolutional neural networks (CNN) are considered as the most effective tool in image diagnosis and processing techniques. In this paper, we studied and applied the modified SSDLite_MobileNetV2 and proposed a solution to always maintain the boundary of the total memory capacity in the following robust bound and applied on the bridge navigational watch & alarm system (BNWAS). The hardware was designed based on raspberry Pi-3, an embedded single board computer with CPU smartphone level, limited RAM without CUDA GPU. Experimental results showed that the deep learning model on an embedded single board computer brings us high effectiveness in application

Effects of perceived corporate social responsibility practices on customers’ satisfaction and perceived value – A study in the food industry in Vietnam

The main purpose of this study is to investigate the effects of perceived Corporate Social Responsibility (CSR) practices on customers’ satisfaction and perceived value. According to the result of the literature review, the studied CSR practices include environmental protection, customer protection, community, HR policies, price, product quality, relationship selling, empathy, and fulfill expectations. To address the research objective, the present study proposed two following research questions: (1) What are factors of CSR practices impacting customers’ satisfaction?; and (2) How do these factors influence customer satisfaction and perceived value? The study approached 236 customers of the food industry to conduct a survey empirically and tested the proposed hypotheses using structural equation modeling. The research findings show that (1), in Vietnamese customers perceptions, Perceived price, Perceived quality and Empathy are three components of CSR practices; (2) these components have positive impacts on Customer satisfaction; and (3) Customer satisfaction has a positive relationship with customers’ perceived value. These findings help to enrich the CSR literature in developing countries like Vietnam, and to confirm the findings of previous studies. Moreover, from the research findings, the present study suggested some managerial implications for firms in the food industry relating to price, product quality and empathy