Catalytic Activity of Cr2O3/sepiolite in the oxidation of benzyl alcohol

Cr2O3/sepiolite samples with different loadings have been prepared through the precipitation method and characterized by several physical methods such as XRD, TEM, BET, and TGA... The as-prepared materials have large surface area, high distribution of Cr2O3 nanoxides on the nanofibrous sepiolite. The catalysts have been tested in the oxidation of benzyl alcohol with t-BuOOH. Chromium oxides were found to be active sites for the oxidation of benzyl alcohol to aldehyde. The catalytic activity varied with reaction time and temperature. The appropriate temperature is about 60-70oC with conversion of 40-60% and benzaldehyde selectivity of 90%

Fe-MCM-22 zeolites: synthesis and study about the states of iron

The Fe-MCM-22 zeolite was successfully synthesized with hexametylenimine template. Several physicochemical techniques (XRD, SEM, BET, AAS, IR and ESR) have been used to characterize this zeolite. Iron exists under three states: isolated ions in tetrahedral lattice positions, in octahedral coordination as isolated ions at cationic positions and as aggregated oxide species or hydroxide phases.Keywords: Fe-MCM-22 zeolite, synthesis, characterization, framework iron

Characteristics and reducibility of nanosized La1-xCexCoO3 perovskites synthesized by reactive grinding

Two (La,Ce)CoO3 perovskite-type oxides prepared by reactive grinding have been characterized by means of X-ray diffraction, N2 adsorption/desorption isotherms, SEM, H2-TPR. Both samples show a nanocrystalline phase and rather high surface area. The thermal stability of cobalt ions in such solids has been studied under reducing conditions. H2-TPR results indicate that the reduction of Co3+ to Co0 occurs in a multiple-step. The partial replacement of La3+ by Ce4+ has promoting effects on the reducibility of cobalt ions. A decreased reduction temperature of cobalt ions in the presence of Ce4+ leads to an increased dispersion of the reduced phase for La0.9Ce0.1CoO3 perovskite precursor. Keywords: perovskite; reduction; cobalt; La-Ce-Co; dispersion; metal

COPPER-MODIFIED MCM-22 AS CATALYSTS FOR HYDROCARBON SELECTIVE CATALYTIC REDUCTION OF NOX

Joint Research on Environmental Science and Technology for the Eart

Straightforward Procedure for Laboratory Production of DNA Ladder

DNA ladder is commonly used to determine the size of DNA fragments by electrophoresis in routine molecular biology laboratories. In this study, we report a new procedure to prepare a DNA ladder that consists of 10 fragments from 100 to 1000 bp. This protocol is a combination of routinely employed methods: cloning, PCR, and partial digestion with restriction enzymes. DNA fragments of 100 bp with unique restriction site at both ends were self-ligated to create a tandem repeat. Once being cloned, the tandem repeat was rapidly amplified by PCR and partially digested by restriction enzymes to produce a ladder containing multimers of the repeated DNA fragments. Our procedure for production of DNA ladder could be simple, time saving, and inexpensive in comparison with current ones widely used in most laboratories

Simple thermal-electrical model of photovoltaic panels with cooler-integrated sun tracker

This paper presents a simple thermal-electrical model of a photovoltaic panel with a cooler-integrated sun tracker. Based on the model and obtained weather data, we analyzed the improved overall efficiency in a year as well as the performance in each typical weather case for photovoltaic panels with fixed-tilt systems with a tilt angle equal to latitude, fixed-tilt systems with cooler, a single-axis sun tracker, and a cooler-integrated single-axis sun tracker. The results show that on a sunny summer day with few clouds, the performance of the photovoltaic panels with the proposed system improved and reached 32.76% compared with the fixed-tilt systems. On a sunny day with clouds in the wet, rainy season, because of the low air temperature and the high wind speed, the photovoltaic panel temperature was lower than the cooler’s initial set temperature; the performance of the photovoltaic panel with the proposed system improved by 12.55% compared with the fixed-tilt system. Simulation results show that, over one year, the overall efficiency of the proposed system markedly improved by 16.35, 13.03, and 3.68% compared with the photovoltaic panel with the fixed-tilt system, the cooler, and the single-axis sun tracker, respectively. The simulation results can serve as a premise for future experimental models

FIRST RECORD OF CANTHARELLUS MINOR IN VIETNAM

This species of mushroom with orange fruiting bodies and yellow flesh grows in clumps on the forest land in the coordinates 11o56'34.45" N, 108o28'33.56" E in the pine (Pinus kesiya) forest, Da Lat City, Lam Dong Province, Vietnam. The results of analysis on the morphology, both macro- and micro-morphological characteristics of this mushroom showed that, pileus: 5-15 mm wide, infundibuliform; yellowish to orange; margin incurred, wavy-liked margin, non-striate; Pileus surface: smooth, scaleless, yellowish; Lamellae: distant, decurrent, not intervenose, concolorous to pileus; Context: concolourous to the pileus, slight sweetness, aromatic flavor; Stipe: cylindrical shape, surface smooth, concolourous to pileus, 1-2 mm diameter, 20-50 mm length; Basidiospores: 6-11.5 x 4-6.5 μm, ovoid-ellipsoid with smooth surface; Basidia: 65 x 10 μm, cornuted 4-6 spores per basidium. Phylogenetic analysis of nrLSU sequence yielded consistent topology in different taxa of Cantharellus. The phylogenetic position of XC02 was obtained and accepted at sub-generic level: subgenus Parvocantharellus. This clade was suggested to be monophyletic, and separated from other sub-generic levels. Morphologically phylogenetically distinct from the other species of clade 4, such as C. appalachiensis, C. tabernensis, C. aff. Congolensis. The highly supported monophyletic group with referent Cantharellus minor was obtained with the bootstrap value of 99, indicated that XC02 was significant closely to Cantharellus minor. Phylogenetic of nrLSU analysis revealed clades with statistical support corresponding to morphological observation, thus, XC2 was concluded as Cantharellus minor

Effects of protein levels of commercial diets on the growth performance and survival rate of rabbitfish (Siganus guttatus) at the nursing stage

This study aimed to determine the effect of a commercial diet's protein level on the fry-to-fingerling stage. Thirty days-old fries having the initial length and weight of 18.25 ± 0.15 mm fish-1 and 0.036 ± 0.50 g fish-1 respectively have been used in this study. Diet having three protein levels i.e. 30% (trial 1 as control), 35% (trial 2), 40% (trial 3), and 45% (trial 4), respectively, have been used to evaluate the effect of protein, and each trial has been repeated three times. During the study, stocking density was allocated to 1000 fish per composite tank with a volume of 1 m3. After 30 days of rearing, the weight of fingerlings in trial 1 reached up to 1.50 ± 0.02 g fish-1 and it was recorded as 1.52 ± 0.01g for trial 2, these two were lower than that of trials 3 and 4, where fingerling weight was reported 1.69 ± 0.01 and 1.58g fish-1 respectively and obtained the best weight compared to others. The length of fingerlings at the end of the experimental period was also changed in different trials and it was recorded 47.12; 46.92; 50.97; and 48.89 mm fish-1 for trail 1, 2, 3, and 4 respectively, among the tested combinations lower fingerlings length was recorded for trial 2 (35% CP), but it is not significantly different for trial 1 and 2 and a significant difference (P < 0.05) was reported for trail 2, 3, and 4. The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVW) in the treatment using 40% protein (trial 3) was the highest at 72.33% (p < 0.05). The results of the study can be concluded that the level of protein has a significant effect on the various growth parameters of fingerlings

Epidemiology of forest malaria in central Vietnam: a large scale cross-sectional survey

In Vietnam, a large proportion of all malaria cases and deaths occurs in the central mountainous and forested part of the country. Indeed, forest malaria, despite intensive control activities, is still a major problem which raises several questions about its dynamics. A large-scale malaria morbidity survey to measure malaria endemicity and identify important risk factors was carried out in 43 villages situated in a forested area of Ninh Thuan province, south central Vietnam. Four thousand three hundred and six randomly selected individuals, aged 10–60 years, participated in the survey. Rag Lays (86%), traditionally living in the forest and practising "slash and burn" cultivation represented the most common ethnic group. The overall parasite rate was 13.3% (range [0–42.3] while Plasmodium falciparum seroprevalence was 25.5% (range [2.1–75.6]). Mapping of these two variables showed a patchy distribution, suggesting that risk factors other than remoteness and forest proximity modulated the human-vector interactions. This was confirmed by the results of the multivariate-adjusted analysis, showing that forest work was a significant risk factor for malaria infection, further increased by staying in the forest overnight (OR= 2.86; 95%CI [1.62; 5.07]). Rag Lays had a higher risk of malaria infection, which inversely related to education level and socio-economic status. Women were less at risk than men (OR = 0.71; 95%CI [0.59; 0.86]), a possible consequence of different behaviour. This study confirms that malaria endemicity is still relatively high in this area and that the dynamics of transmission is constantly modulated by the behaviour of both humans and vectors. A well-targeted intervention reducing the "vector/forest worker" interaction, based on long-lasting insecticidal material, could be appropriate in this environment

The use of reproductive healthcare at commune health stations in a changing health system in Vietnam

Background: With health sector reform in Vietnam moving towards greater pluralism, commune health stations (CHSs) have been subject to growing competition from private health services and increasing numbers of patients bypassing CHSs for higher-level health facilities. This study describes the pattern of reproductive health (RH) and family planning (FP) service utilization among women at CHSs and other health facilities, and explores socio demographic determinants of RH service utilization at the CHS level