Optimization of the leaching process of the printed circuit boards production’s sludge for copper recovery via electrolysis

Copper is the main component of printed circuit boards (PCBs) which is the main part of an electronic device. The manufacture of PCBs often releases huge amount of sludge which contained copper. Derived from the demand of the industrial park about the wasted sludge treatment and the reducing of the plantation of natural mineral resources, the copper recovery process from PCBs manufacture's wasted sludge was studied. The process of copper leaching by sulfuric acid solution was studied using experimental planning methods using the simulation software Modde 5.0. The parameters were calculated and simulated to evaluate the effect of the acid concentration, leaching time, and the ratio between the solid and liquid phases on the leaching efficiency. The obtained results by simulation were compared with real experimental results. The obtained results from this study are planning in the actual deployment of the Hanoi Urban Environment One Member Limited Company in Vietnam. Keywords. Printed circuit board, copper sludge, leaching

Acceptance patterns and decision-making for human papillomavirus vaccination among parents in Vietnam: an in-depth qualitative study post-vaccination

BACKGROUND: The GAVI Alliance’s decision in late 2011 to invite developing countries to apply for funding for human papillomavirus (HPV) vaccine introduction underscores the importance of understanding levels of HPV vaccine acceptance in developing country settings. In this paper, we present findings from qualitative research on parents’ rationales for vaccinating or not vaccinating their daughters (vaccine acceptance) and their decision-making process in the context of an HPV vaccination demonstration project in Vietnam (2008–2009). METHODS: We designed a descriptive qualitative study of HPV vaccine acceptability among parents of girls eligible for vaccination in four districts of two provinces in Vietnam(a). The study was implemented after each of two years of vaccinations was completed. In total, 133 parents participated in 16 focus group discussions and 27 semi-structured interviews. RESULTS: Focus group discussions and in-depth interviews with parents of girls vaccinated revealed that they were generally very supportive of immunization for disease prevention and of vaccinating girls against HPV. The involvement of the National Expanded Program of Immunization in the demonstration project lent credibility to the HPV vaccine, contributing to high levels of acceptance. For parents who declined participation, concerns about side effects, the possibility that the vaccine was experimental, and the possible impact of the vaccine on future fertility rose to the surface. In terms of the decision-making process, many parents exhibited ‘active decision-making,’ reaching out to friends, family, and opinion leaders for guidance prior to making their decision. CONCLUSION: Vietnam’s HPV vaccination experience speaks to the importance of close collaboration with the government to make the most of high levels of trust, and to reduce suspicions about new vaccines that may arise in the context of vaccine introduction in developing country settings

A new loach species of the genus Vanmanenia (Actinopterygii: Cypriniformes: Gastromyzontidae) from hill streams of Vietnam

Recent ichthyofauna surveys in Phia Oac-Phia Den National Park, Vietnam, yielded 16 specimens of loach representing the genus Vanmanenia. These specimens were uniform in morphology and distinct from known species, leading to the designation of a new species, Vanmanenia duci sp. nov. This species is distinguished from congeners by the following combination of characters: pectoral fin: I, 15; pelvic fin: I, 8; lateral line scales 77–83; the distance from the anus to the posterior insertion of the pelvic fin being greater than from the anus to the anal fin origin; a lateral black stripe from the gill opening to the caudal fin base; a black spot at the caudal fin origin equal to the eye diameter; and a lower lip with three large papillae, with the middle one being larger. The new species differs from Vanmanenia caldwelli (Nichols, 1925) by its mouth soft-tissue structures and lower morphometric values and from Vanmanenia ventrosquamata (Mai, 1978) and Vanmanenia caobangensis Nguyen, 2005 by having more lateral line scales and lower body depth. Additionally, Vanmanenia duci sp. nov. has a larger eye and wider interorbital space compared to other species in Vietnam. This species is found in the Red River basin in Vietnam and the Bang Giang River flowing into China, indicating high potential for freshwater fish diversity in these river systems

Crystallography: Deep understanding the mechanism of -form nucleation in cooling crystallization of L-glutamic acid

The mechanism of heterogeneous β-form nucleation was investigated during the phase transformation of L-glutamic acid in the stirring cooling crystallization. In the present study, a new mechanism of heterogeneous β-form nucleation was explored, where the β-form nuclei was favorably crystallized on the (001) and (011) surfaces rather than the (111) surface of α-form crystal during the phase transformation. This result was confirmed via the molecular simulation, in which the functional groups of molecule on various surfaces of α-form crystal were different, so the degree of lattice matching (E) between the α-form substrate surfaces and β-form molecule aggregate was distinguished and ordered as (001) (011) (111), meaning that the nucleation of heterogeneous β-form was more facilitated on the (001) and (011) surfaces compared to that on the (111) surface of α-form crystal. Keywords. Crystallization, crystallography, polymorphism, nucleation, crystal growth

Morphological Traits and Nuclear Genetic Diversity of Coptis sp. in Hoang Lien National Park, Lao Cai Province, Vietnam

Coptis is a medicinal plant genus in the Ranunculaceae family, and is also known as “Hoang Lien” in Vietnamese. It is a perennial herb that grows in some regions of the world. However, Coptis is endangered and faces global threats. This study aimed to characterize some main morphological characteristics and performed a phylogenetic analysis of 11 samples of Coptis sp. collected from Hoang Lien National Park using nuclear DNA sequence analyses. All sample species have unique morphological traits with distinct yellow rhizomes and basal leaves with five segments. The petiole measures 13-25 cm and is smooth, while the leaf blade is ovate, ranging from 7 to 15.5 cm in length and 5.5 to 14 cm in width. The leaves are subleathery, glabrous on the underside, and sparsely puberulous on the veins on the upper side. The molecular characterization of Coptis sp. genotypes was determined by ITS markers. The length of the ITS1-ITS2 sequences varied from 363 to 371 nucleotides. The average nucleotide composition was 17.11% A, 31.25% C, 32.247% G and 19.41% T, respectively. The comparison with the GenBank database showed that the samples had 95.71- 96.37% similarity with the species Coptis quinquesecta. The genetic distance among the 11 Coptis samples fluctuated from 0.00 to 0.017. A neighbor-joining tree was constructed to show the genetic relationships among Coptis samples. The results indicated that this endangered species had low levels of genetic diversity. The study has provided valuable information for genetic-based conservation of this rare endemic species and suggested some conservation strategies

Complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus) of Vietnam

The complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus, Dong Tao) was obtained by PCR and sequencing. The complete mitogenome was 16,783 bp in length, with the nucleotide composition for A, T, C, G was 30.29%, 23.75%, 32.48%, and 13.48%, respectively. The mitogenome of Dong Tao chicken contained a non-coding control region (D-loop), 2 rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis revealed that breed Dong Tao chicken breed was sister-close to G. gallus breed Guangxi, and paraphyletic to G. spadiceus, S. jabouillei, and a range of Chinese indigenous, ie. breeds Rugao and Taoyuan

Unexpected cases in field diagnosis of African swine fever virus in Vietnam: The needs consideration when performing molecular diagnostic tests

Background: The first confirmed case of African swine fever (ASF) in Vietnam was reported officially in February 2019. To date, ASF virus (ASFV) have been detected in 63/63 provinces in Vietnam. Currently, real-time polymerase chain reaction (PCR) is considered to be a powerful tool for viral detection in field samples, including ASFV. However, some recent reports have suggested that mismatches in primer and probe binding regions may directly affect real-time PCR qualification, leading a false-negative result.Aim: This study aims to further examine a conflicting result obtained from two OIE recommended methods, conventional PCR and real-time PCR, for ASFV detection.Methods: Two ASF suspected pigs from different provinces in the north of Vietnam were selected for this study based on clinical signs and postmortem lesions. The different results obtained by OIE-recommended conventional PCR and real-time PCR were further analyzed by the Sanger sequencing method and virus isolation in combination with hemadsorption (HAD) test using porcine alveolar macrophages cells.Results: The results showed that when the primer sequence matched perfectly with the sequences of field isolates, a mutation in probe binding region was found, indicating that a single mismatch in the probe binding site may cause a false-negative result by real-time PCR in detecting ASFV in clinical samples in Vietnam. An agreement between conventional PCR, using PPA1/PPA2 primers and two golden standard methods, virus isolation in combination with HAD assay, and sequencing method was observed in this study.Conclusion: A single mismatch in the probe binding site caused a failse-negative result by realtime PCR method in field diagnosis of ASFV. The needs consideration when selecting the appropriate molecular diagnostic methods is based on the current databases of ASFV sequences,  particularly for epidemiological surveillance of ASF. Keywords: African swine fever, PCR, Pigs, Real-time PCR, Vietna

DETERMINATION THE PRIORITY OF FACTORS INFLUENCING OVERSEAS INVESTMENT DESTINATIONS OF BUSINESSES USING AN ANALYTIC HIERARCHY PROCESS METHOD

Because of the great benefits overseas investment brings, countries and businesses are increasingly concerned with the question of an ideal investment destination. Many studies have shown that, factors of the consumption market, the infrastructure and resources, economic and political environment have a significant impact on the decision to choose an investment location, however the priority order of these factors are different for various research spaces. By studying the specific case of Viettel Group - one of the largest telecommunications groups in Vietnam that is having many international investment activities in recent years, the study has been verified the priority order of factors influencing the decision to choose an overseas investment location of this corporation. The research outcomes show that the group of factors that have the most influence on investment decisions is the group "Consumption market", more specifically, the sub-factor "Market Size" is considered more than the others.    Keywords: Investment Destinations, Foreign Investment Decision, Analytic Hierarchy Process