Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Publication year range
1.
Chemistry ; 23(34): 8252-8261, 2017 Jun 16.
Article in English | MEDLINE | ID: mdl-28421629

ABSTRACT

Heteroatom doping is a promising approach to improve the properties of carbon materials for customized applications. Herein, a series of Cu catalysts supported on boron-doped carbon nanotubes (Cu/xB-CNTs) were prepared for the hydrogenation of dimethyl oxalate (DMO) to ethanol. The structure and chemical properties of boron-doped catalysts were characterized by XRD, TEM, N2 O pulse adsorption, CO chemisorption, H2 temperature-programmed reduction, and NH3 temperature-programmed desorption, which revealed that doping boron into CNT supports improved the Cu dispersion, strengthened the interaction of Cu species with the CNT support, introduced more surface acid sites, and increased the surface area of Cu0 and especially Cu+ sites. Consequently, the catalytic activity and stability of the catalysts were greatly enhanced by boron doping. 100 % DMO conversion and 78.1 % ethanol selectivity could be achieved over the Cu/1B-CNTs catalyst, the ethanol selectivity of which was almost 1.7 times higher than that of the catalyst without boron doping. These results suggest that doping CNTs with boron is an efficient approach to improve the catalytic performance of CNT-based catalysts for hydrogenation of DMO. The boron-doped CNT-based catalyst with improved ethanol selectivity and catalytic stability will be helpful in the development of efficient Cu catalysts supported on non-silica materials for selective hydrogenation of DMO to ethanol.

2.
Chem Asian J ; 12(3): 366-371, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-27918648

ABSTRACT

We report a one-pot and eco-friendly synthesis of carbon-supported cobalt nanoparticles, achieved by carbonization of waste biomass (rice bran) with a cobalt source. The functionalized biomass provides carbon microspheres as excellent catalyst support, forming a unique interface between hydrophobic and hydrophilic groups. The latter, involving hydroxyl and amino groups, can catch much more active cobalt nanoparticles on surface for Fischer-Tropsch synthesis than chemical carbon. The loading amount of cobalt on the final catalyst is much higher than that prepared with a chemical carbon source, such as glucose. The proposed concept of using a functionalized natural carbon source shows great potential compared with conventional carbon sources, and will be meaningful for other fields concerning carbon support, such as heterogeneous catalysis or electrochemical fields.

3.
Ind Health ; 44(1): 161-5, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16610554

ABSTRACT

This study was conducted to clarify the characteristics of small-scale enterprises (SSEs) with fewer than 50 workers, which employ 62.2% of all Japanese workers. Subjects were 71,183 workers employed at 1,761 workplaces in Tochigi, Japan, in 2002. Frequencies of abnormal lifestyle and health check-up data were described according to the category of the enterprise. Adjusted odds ratios (ORs) of the abnormal findings were calculated by logistic regression analysis. Dose-response relationships were calculated by trend tests. The frequency of abnormal findings was higher in SSEs than in other categories of enterprises. The ORs of work intensity, alcohol consumption, current smoker, and the Brinkmann index were higher in SSEs than in large-scale enterprises (LSEs) and were also significant in trend tests. The ORs of audiometry, hypertension, glucose in urine and ECG in males and females, BMI, liver function, lipid metabolism, and blood sugar in females, chest X-ray, and anemia in males were higher in SSEs. Audiometry, hypertension, anemia, ECG in both males and females; chest X-ray, and glucose in urine in males, and liver function, lipid metabolism and blood sugar in females showed significant results in trend tests. Overall health and healthy lifestyle in SSEs were worse than in LSEs.


Subject(s)
Employment , Health Status Indicators , Life Style , Commerce , Female , Humans , Japan/epidemiology , Male
4.
Rinsho Byori ; 53(7): 599-607, 2005 Jul.
Article in Japanese | MEDLINE | ID: mdl-16104528

ABSTRACT

OBJECTIVE: To determine age- and sex-specific reference intervals for 10 health examination items in Japanese adults. METHODS: Health examination data were accumulated from 24 different prefectural health service associations affiliated with the Japan Association of Health Service. Those who were non-smokers, drank less than 7 days/week, and had a body mass index of 18.5-24.9kg/m2 were sampled as a reference population (n = 737,538; 224,947 men and 512,591 women). After classified by age and sex, reference intervals for 10 health examination items (systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, glucose, uric acid, AST, ALT, gamma-GT, and hemoglobin) were estimated using the parametric and nonparametric methods. RESULTS: In every item except for hemoglobin, men had higher reference intervals than women. Systolic blood pressure, total cholesterol, and glucose showed an upward trend in values with increasing age. Hemoglobin showed a downward trend in values with increasing age. Triglyceride, ALT, and gamma-GT reached a peak in middle age. Overall, parametric estimates showed narrower reference intervals than non-parametric estimates. CONCLUSION: Reference intervals vary with age and sex. Age- and sex-specific reference intervals may contribute to better assessment of health examination data.


Subject(s)
Data Interpretation, Statistical , Health Services , Physical Examination/standards , Adult , Age Distribution , Asian People , Female , Humans , Japan , Male , Reference Values , Sex Distribution
SELECTION OF CITATIONS
SEARCH DETAIL
...