443 research outputs found
Zooplankton from Can Giuoc River in Southern Vietnam
In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43-), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment.
The results showed that pH ranged from 6.7 to 7.6 during the monitoring. The TSSs were between 34â117 mg/L. The DO and BOD5 were from 0.6 to 3.8 mg/L and from 6.3 to 13.2 mg/L, respectively. The NH4+ and PO43- concentrations ranged from 0.44 to 3.23 and from 0.08 to 1.85 mg/L, respectively. The coliform number was between 9.3x103â9.3x104 MPN/100 mL. The zooplankton analyses showed that there were 31 species of coelenterates, rotatoria, oligochaetes, cladocerans, copepods, ostracods, mysidacea, and 8 larval types. Thereof, the species of copepods were dominant in the species number. The zooplankton density ranged from 9 500 to 23 600 individuals/m3 with the main dominant species of Moina dubia (Cladocera), Thermocyclops hyalinus, Acartia clausi, Oithona similis (Copepoda), and nauplius copepods. The biodiversity index values during the monitoring were from 1.47 to 1.79 characteristic of mesotrophic conditions of the aquatic environment. Besides, the species richness positively correlated with pH, TSS, DO, BOD5, NH4+, PO43-, and coliform, while the zooplankton densities got a positive correlation with DO, BOD5, NH4+, PO43-, and coliform. The results confirmed the advantage of using zooplankton and its indices for water quality assessment
MATERIAL FLOW ANALYSIS (MFA) AND ENERGY BALANCE ANALYSIS (EBA) AS TECHNICAL TOOLS FOR WASTEWATER POLLUTION CONTROL IN TEXTILE AND DYEING INDUSTRY â A CASE STUDY
The textile and dyeing industry consumes a large amount of water and discharges to the environment many pollutants including dyestuffs, auxiliaries, others. In this study, a selected textile and dyeing company was representing modern factory in Vietnam. Using STAN software, the authors have quantified and analyzed the material flows of the production lines and of the main pollutants in wastewater. Comparing with âbusiness as usualâ scenario, a new scenario with treatment and reuse of wastewater has been introduced. The discharge volume of wastewater from company was about 3,608.96 m3/day (or 1,317,270.4 m3/year). Loadings of the main pollutants in wastewater as COD, TSS, T-P and T-N were 1419.95, 1571.36, 17.77 and 50.16 ton/year, respectively. One meter of produced fabric consumes 0.025 m3 of water. Energy consumption of the wastewater treatment station was analyzed by SANKEY software. The energy consumption rate was 1.695 kWh per m3 of wastewater. Reuse of wastewater could save 1,129.05 kWh per day of electricity and 1,804.48 m3 per day of fresh water to be taken from the river source. Ozonation was the most consuming energy process at the wastewater treatment station, accounting for 58.88% of total wastewater treatment energy consumption
Adsorption Isotherm Measurement and Correlation of Toluene and n-Hexane on Activated Carbon in an Aqueous Solution / by Nguyen My Anh Hoa, QD 501 .H678 2005
Thenumber of hazardous waste disposals reported has increased in recentyearsdue to improper
management of chemical generated by chemical and petrochemical industries. Volatile organic
compounds are one of the major pollutants to the environment. Two of the volatile organics
compounds selected for this study are toluene and n-hexane are The adsorption measurement in
aqueous solutions has been carried out by using batch system at 35°C, 55°C and 65°C with the
range of initial concentration between 10 to 200ppm. There are three types of activated carbon
that have been used, which are Granular Activated Carbon (GAC) 2.5mm, Granular Activated
Carbon 0.25mm, and Powder Activated Carbon.
The objectives of this study are to determine the adsorption isotherms of toluene and n-hexane
on activated carbon through the adsorption process, to investigate the effect of temperature on
the adsorption capacity of toluene and n-hexane, and to model the experimental adsorption
isotherm databy using the established adsorption isotherm equations on activated carbon.
The equilibrium concentrations have been analyzed using UV-Vis Spectrophotometer and Gas
Chromatography with Purge and Trap after the solutions were adsorbed for 24 hours.
The toluene adsorption isotherm has the S-shaped form and of type V isotherm based on the
classification of Brunaeur, Deming, Deming and Teller (BDDT). Among the three temperature
conditions, it is found that the adsorption favors the lowest temperature (35°C). This indicates
that adsorption process is exothermic, lower the temperature will shift the adsorption
equilibrium to adsorption rather than desorption. GAC 2.5 mm is found to have the highest
adsorption capacityamongthe others. It is impossible to carry out the experimentwith n-hexane
due to its high volatility. The amount of n-hexane is considered negligible in aqueous solution
and adsorption process does not require.
Freundlich isotherm is the most popular model which is widely used in the correlation of liquid
adsorption. Sips isotherm which is the combination between Langmuirand Freundlichequation
is an alternative model. However, the techniques were not successful with toluene isotherm
measurement
La perturbation du locus Nr2f1-K12 entraine une différenciation gliale précoce dans un nouveau modÚle murin de mégacÎlon aganglionnaire
La maladie de Hirschsprung est une affection congĂ©nitale de la motilitĂ© intestinale caractĂ©risĂ©e par un segment aganglionnaire dans le cĂŽlon terminal. Un criblage gĂ©nĂ©tique par mutation insertionnelle alĂ©atoire chez la souris nous a permis dâidentifier la lignĂ©e transgĂ©nique Spot dont les homozygotes souffrent de mĂ©gacĂŽlon aganglionnaire. Lâanalyse dâintestins dâembryons mutants a rĂ©vĂ©lĂ© une baisse de prolifĂ©ration et un dĂ©lai de migration des cellules de la crĂȘte neurale entĂ©riques (CCNe) progĂ©nitrices dus Ă leur diffĂ©renciation gliale prĂ©coce, entrainant un dĂ©faut de colonisation de lâintestin et une aganglionose du cĂŽlon. Le sĂ©quençage du gĂ©nome Spot indique que le transgĂšne sâest insĂ©rĂ© Ă lâintĂ©rieur du locus K12-Nr2f1 sur le chromosome 13, une rĂ©gion dĂ©pourvue de gĂšnes prĂ©alablement associĂ©s Ă la maladie, perturbant Ă©galement une sĂ©quence non-codante trĂšs conservĂ©e dans lâĂ©volution. K12 est un gĂšne dâARN long non codant (ARNlnc) et antisens du gĂšne Nr2f1, lui-mĂȘme impliquĂ© dans la gliogĂ©nĂšse du systĂšme nerveux central. Le sĂ©quençage du transcriptome des CCN a montrĂ© une surexpression de Nr2f1 et des formes courtes de K12 chez Spot et des essais lucifĂ©rase ont rĂ©vĂ©lĂ© lâactivitĂ© rĂ©pressive de lâĂ©lĂ©ment conservĂ©. Nous avons observĂ© lâexpression de K12 dans les CCNe et sa localisation subcellulaire dans des zones transcriptionnellement actives du noyau. Avec lâĂ©mergence des ARNlnc rĂ©gulateurs, ces donnĂ©es nous permettent de pointer deux nouveaux gĂšnes candidats associĂ©s Ă une diffĂ©renciation gliale prĂ©maturĂ©e du SNE menant au mĂ©gacĂŽlon aganglionnaire, en supposant que la rĂ©gulation de Nr2f1 se fait par son antisens, K12.Hirschsprung disease is a congenital intestinal motility disorder characterized by an aganglionic segment in the distal colon. A genetic screen performed via random insertional mutagenesis in mice allowed identifying the Spot line, whose homozygotes suffer from an aganglionic megacolon. The analysis of mutant embryonic intestines revealed a decreased proliferation rate and a delay in migration of the enteric neural crest cell (eNCC) progenitors, secondary to their early glial differentiation, resulting in failure to properly colonize the intestine. Sequencing of the Spot genome indicated that the transgene was inserted into the K12-Nr2f1 locus on chromosome 13, a region devoid of genes associated with the disease, and disrupted in addition a highly conserved non-coding sequence. K12 is an uncharacterized long non-coding RNA (LncRNA) gene antisense to the Nr2f1 gene, which is involved in gliogenesis in the central nervous system. Sequencing of the eNCC transcriptome revealed an overexpression of Nr2f1 and short forms of K12 in Spot, and luciferase assays showed repressive activity of the conserved element. We observed the expression of K12 in the eNCC and its subcellular localization in transcriptionally active zones of the nucleus. With the recent emergence of LncRNA regulators and supposing that the regulation of Nr2f1 is done by its antisense K12, these data allowed us identifying two new candidate genes associated with a premature glial differentiation leading to aganglionic megacolon
Adsorption Isotherm Measurement and Correlation of Toluene and n-Hexane on Activated Carbon in an Aqueous Solution / by Nguyen My Anh Hoa, QD 501 .H678 2005
The application of green YPO4:Ce3+,Tb3+ and red LiLaO2:Eu3+ layers to remote phosphor LED
Remote phosphor structure is commonly limited in color quality, but has greater luminous flux when comparing to structures with in-cup or conformal coating. From this dilemma, various researches with advance modifications have been proposed to perfect the chromatic performance of remote structure. In this research, we reach higher color quality by obtaining better values in quality indcators such as color rendering index (CRI) and color quality scale (CQS) with the dual-layer phosphor in our remote white light-emitting diodes (WLEDs). The idea is to ultize WLEDs with 7000 K correlated color temperature (CCT) and create dual-layer configuration with yellow phosphor YAG:Ce3+ under green phosphor YPO4:Ce3+,Tb3+ or red phosphor LiLaO2:Eu3+. After that, we search for suitable concentration of LiLaO2:Eu3+ for addition in order to acquire the finest color quality. The result shows that WLED with LiLaO2:Eu3+ has better CRI and CQS as the higher the concentration of LiLaO2:Eu3+, the larger CRI and CQS due to increased light scattered in WLEDs. Meanwhile, the green phosphor layer YPO4:Ce3+,Tb3+ give advantages to luminous flux. However, the reduction in luminous flux and color quality occurs when the concentration of LiLaO2:Eu3+ and YPO4:Ce3+,Tb3+ over increase. Results are verified by Mie theory and Beerâs Law and can be applied to practical manufacturing of high quality WLEDs
The application of green YF3:Er3+,Yb3+ and red MgSr3Si2O8:Eu2+,Mn2+ layers to remote phosphor LED
White light-emitting diodes (WLEDs) with quantum dots (QDs) and phosphor have pulled in huge consideration because of their incredible shading rendering capacity. In the bundling procedure, a QDs film and a phosphor silicone layer will in general be isolated for lessening the reabsorption misfortunes and keeping the QDs surface molecules in a good condition. This examination explored the bundling succession of QDs and phosphor layers to the optical and warm exhibitions of WLEDs. The emitted optical power and PL spectra were estimated and dissected, while an infrared warm imager was utilized to reenact and approve tentatively the temperature fields. The results reveal that at 60 mA, WLEDs with green QDs-on-phosphor type accomplished lumen output (LO) of 1578 lm, with shading rendering record (CRI) of Ra = 60, while the red QDs-on-phosphor type WLEDs exhibited lower LO of 1000 lm, with Ra = 82. In addition, the QDs-onphosphor type WLEDs generated less warmth than the other, and as a result, the most noteworthy temperature in this packaged type was lower than the other. Additionally, its temperature contrast can arrive at 12.3°C. Along these lines, regarding bundling arrangement, the QDs-on-phosphor type is an ideal bundling design to better the optical productivity and shading rendering capacity, as well as lower gadget temperature
Acquiring higher lumen efficacy and color rendering index with green NaYF4:Er3+Yb3+ and red α-SrO·3B2O3:Sm2+ layers for designing remote phosphor LED
Lighting devices that apply diodes to create white light-emitting diodes (WLEDs) can achieve remarkable results in color quality, especially those containing quantum dots (QDs) and phosphor. The technique to create an appropriate package is providing spaces between the QDs and phosphor components which helps decrease the ratio of the reabsorption losses and keeps the QDs surface ligands constant. The research aims to perfect the constructing method of remote phosphor configuration containing quantum dots and phosphor materials that based on lighting properties and temperature feature of WLEDs. The infrared thermography is the tool to measure and analyze total emitted light and emission ranges of the device. This device is also used in temperature simulation and experimental verification. At the given mA of 60, the WLEDs structure with green QDs layer above the phosphor layer results in 996 lm luminous flux (LF), and Ra = 57 in color rendering ability. Meanwhile, luminous flux of WLEDs with red QDs-on-phosphor structure is 632, and Ra = 70. Furthermore, comparing with the green QDs-on-phosphor type, the red QDs-on-phosphor type emitted less LF. However, the red QDs-on-phosphor type can be the most effective package design to achieve color rendering ability
Improving optical properties of remote phosphor LED using green Y2O3:Ho3+ and red Mg4(F)(Ge, Sn)O6:Mn2+ layers
The lighting device that employs diodes to create white light (WLEDs) with quantum dots (QDs) and phosphor layers is a promising lighting method that is increasingly used in many fields on account of the remarkable color expressing ability. The QDs film is usually placed apart from the phosphor layer according to the packaging configuration to prevent light loss due to backscattering as well as preserve the consistency of the ligands on the QDs surface. The article also conducted experiments to compare the lighting properties and thermal output of the two packaging orders of QDs and phosphor. The heat discharing ranges were simulated with thermography technology, moreover, other parameters such as light energy emission and PL spectra are acquired to evaluate the efficiency of the packaging order. The results from the practical experiment show that while under 10% wt., the luminous output (LO) of green QDs-on-phosphor structure reaches 1130 lm, higher than the red QDs-on-phosphor structure with 878 lm, and the color rendering value in the configuration with red QDs on phosphor is Ra = 74 are higher than Ra = 68 index of the green QDs-on-phosphor structure. As a result, the QDs-on-phosphor is determined as the better packaging configuration to choose to achieve an overall improvement in lighting efficiency, color rendering inde
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