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1.
The problems related to our strong dependency on fossil fuels, i.e. greenhouse effect, energy dependency, urban pollution, are of growing importance in recent years. European Union (EU) Action plan of 2003, which had originated from Kyoto Agreement, defined a strategy for substitution of 20% of conventional fuel with the alternative one by 2020. Proved advantages of biodiesel usage in the system of public transport of passengers, with regard to exhaust gases emission above all, have been the decisive determinants for the actual promotion of biodiesel as ecologically “clean” fuel, while its wider usage gives important contribution to sustainable development of cities. This paper presents results of biodiesel-test run in Belgrade, as a part of the project BIO-PEX, which relates to the usage of this alternative fuel in real operating conditions in urban public transport system, with special emphasis on technical, ecological and operational aspects of biofuel usage. 相似文献
2.
Summary. A 1,1'-binaphthol based optically active oligomer 6 with 3,3'-acetylene spacer was prepared from 2,2'-dimethoxy-1,1'-binaphthalene 3 through the palladium-catalyzed Stille coupling reaction. The high optical rotation and CD spectrum varified the main chain
chirality of the oligomer. The photophysical properties of 6, absorption, excitation and fluorescent spectra, demonstrated that the oligomer molecule had a conjugated structure, but
twisting and rigid conformation would reduce the delocalization along the backbone. 相似文献
3.
Vasomotor, somatic, and psychological symptoms associated with menopause are often treated with hormone replacement therapy (HRT), but the role of nonpharmacological interventions has received little attention. Two studies used the Profile of Mood States (POMS) and Women's Health Questionnaire (WHQ) to examine the effects of exercise among 4 groups of Australian women: premenopausal, perimenopausal, postmenopausal without HRT, and postmenopausal with HRT. Study 1, a comparison of exercisers and nonexercisers, showed that exercisers' moods were significantly more positive than sedentary women's moods, regardless of menopausal state. Exercising women also scored lower on somatic symptoms and memory-concentration difficulties. Study 2 examined the acute effects of aerobic exercise (premenopausal, postmenopausal without HRT, and postmenopausal with HRT) and found significant enhancements in mood and reductions in reported somatic and vasomotor symptoms immediately following an aerobic class. Exercise may assist in the alleviation of some menopausal symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Slaven Jurić Marina Jurić Giovanna Ferrari Anet Režek Jambrak Francesco Donsì 《International Journal of Food Science & Technology》2021,56(10):4907-4914
Tomato processing residues are still rich in bioactive compounds that may be recovered and reused, with environmental and economic benefits. This short communication discloses for the first time that the high-pressure homogenisation (HPH) treatment of tomato residues in the presence of water and sunflower oil is able to promote the extraction of bioactive compounds concurrently to the formation of an oil-in-water emulsion stabilised by the micronized residues. The mechanical disruption effect of HPH improved the mass transfer of lycopene into the oil phase, and formed fine fibrous debris, improving stabilisation and visual appearance of the emulsion. Results showed a progressive increase of lycopene concentration in the cream phase up to 5 HPH passes and a concurrent reduction of its content in the pellet. Total polyphenols content and antioxidant activity in the aqueous phase gradually decreased when increasing the number of passes, suggesting their progressive transfer in the cream phase. The proposed process that relies on a purely physical treatment and uses only water/sunflower oil as extraction media resulted in the production of a lycopene-rich cream of potential use as a functional food ingredient. 相似文献
5.
Darikha Kudasova Botagoz Mutaliyeva Kristina Vlahovi
ek-Kahlina Slaven Juri Marijan Marijan Svetlana V. Khalus Alexander V. Prosyanik Suzana egota Nikola pani Marko Vincekovi 《International journal of molecular sciences》2021,22(5)
A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture 相似文献
6.
Steady-state kinetics on the reaction catalyzed by the beta-glucosidase of Aspergillus niger were carried out to evaluate the kinetic parameters, Km and ko, for phenyl beta-D-glucosides. The ko/Km values, which may relate to productive binding at subsites, were found to correlate with the substituent constant pi (hydrophobicity), suggesting that subsite 2 has a hydrophobic character. A "hydrophobic-driven" mechanism is considered to contribute to the productive E-S complex for recognition of the substrate. 相似文献
7.
Graphene synthesis by ion implantation 总被引:1,自引:0,他引:1
We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with controllable thickness. Thermally annealing polycrystalline nickel substrates that have been ion implanted with carbon atoms results in the surface growth of graphene films whose average thickness is controlled by implantation dose. The graphene film quality, as probed with Raman and electrical measurements, is comparable to previously reported synthesis methods. The implantation synthesis method can be generalized to a variety of metallic substrates and growth temperatures, since it does not require a decomposition of chemical precursors or a solvation of carbon into the substrate. 相似文献
8.
This study examines the utility of a sleeve anastomosis with comparison to conventional end to end anastomosis. Thirty New Zealand white rabbits were randomized to sleeve (n = 15) or end-to-end (n = 15) small bowel anastomosis. Five rabbits of each group were sacrificed at 3 days, 7 days, and 6 weeks. Anastomoses were assessed for integrity, bursting strength, and stenosis and examined histologically. Ten control specimens of small bowel were tested for bursting pressure. Three rabbits died postoperatively (1 sleeve and 2 end-to-end). A fourth rabbit (sleeve) was sacrificed early at 3 weeks and had a total stenosis at the anastomosis. The remaining 26 rabbits were reoperated at the prescribed times. There was no evidence of infection or dehiscence in any of these rabbits. Both end-to-end and sleeve anastomoses were equivalent for bursting pressure at all times and, at 7 days and 6 weeks, were similar to controls. The stenotic index revealed no evidence of proximal dilation suggestive of obstruction in the 26 rabbits. For sleeve anastomoses the length of the projected bowel into the lumen persisted at the 6-week stage. Histologically there was good evidence of healing in both the sleeve and end-to-end anstomoses and the serosal surface of the sleeved bowel had epithelialized. Sleeve anastomosis has been demonstrated to heal well and to be as strong as conventional end-to-end anastomosis. Further studies are warranted to determine its role in intestinal anastomosis and potential as a valve. 相似文献
9.
Joseph O’Neil Marilyn J. Bull James E. Slaven Judith L. Talty 《Accident; analysis and prevention》2012
Purpose
This study compares child passenger safety (CPS) practices of grandparents versus parents and determines grandparents’ opinions on car safety seats (CSS), barriers to use, and ways to transport grandchildren safely.Methods
Observational surveys were conducted on a convenience sample of drivers transporting children younger than sixteen years at 25 locations by certified child passenger safety technicians observing children in motor vehicles and recorded use of child passenger restraints. The drivers were surveyed on their knowledge, attitudes, beliefs, and practices regarding CPS. Data from drivers identifying themselves as grandparents were analyzed; also, three grandparent focus groups provided opinions on CPS practices.Results
During the study 1758 parents transporting 2713 children and 284 grandparents transporting 391 grandchildren were included. While most drivers were restrained and used child occupant restraints, almost 25% of parents and grandparents chose the incorrect seat to transport the child, and greater than 68% had at least one harness error. Grandparents were more likely to have looser lower anchor straps or seat belts and have children younger than thirteen years in the front seat.The focus group-grandparents had a favorable attitude toward CSS. Grandparents acknowledged the need for CSS but opined that CSS were difficult to use. Physical barriers included arthritis, back pain, mobility, decreased strength, and vision problems.Conclusions
Grandparents and parents were equally likely to use CSS and choose correct seats. Compared to parents, grandparents were more likely to travel with their grandchildren with CSS installed with looser harnesses or an installed CSS with looser seat belt or lower anchors. Additionally, grandparents were more likely to have a child younger than thirteen years in the front seat. The use of community resources such as permanent fitting stations could help grandparents improve a grandchild's travel safety. 相似文献10.
This paper presents a study of lossless image compression of fullband and subband images using predictive coding. The performance of a number of different fixed and adaptive predictors are evaluated to establish the relative performance of different predictors at various resolutions and to give an indication of the achievable image resolution for given bit rates. In particular, the median adaptive predictor is compared with two new classes of predictors proposed in this paper. One is based on the weighted median filter, while the other uses context modelling to select the optimum from a set of predictors. A graphical tool is also proposed to analyse the prediction methods. Simulations of the different predictors for a variety of real world and medical images, evaluated both numerically and graphically, show the superiority of median based prediction over this proposed implementation of context model based prediction, for all resolutions. The effects of different subband decomposition techniques are also explored. 相似文献