1,022 research outputs found

    Recent advances in the chemistry of metal carbamates

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    Following a related review dating back to 2003, the present review discusses in detail the various synthetic, structural and reactivity aspects of metal species containing one or more carbamato ligands, representing a large family of compounds across all the periodic table. A preliminary overview is provided on the reactivity of carbon dioxide with amines, and emphasis is given to recent findings concerning applications in various fields

    Non-precious metal carbamates as catalysts for the aziridine/CO2coupling reaction under mild conditions

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    The catalytic potential of a large series of easily available metal carbamates (based on thirteen different non-precious metal elements) was explored for the first time in the coupling reaction between 2-aryl-aziridines and carbon dioxide, working under solventless and ambient conditions and using tetraalkylammonium halides as co-catalysts. The straightforward synthesis of novel [NbCl3(O2CNEt2)2],NbCl, and [NbBr3(O2CNEt2)2],NbBr, is reported. The niobium complexNbCl, in combination with NBu4I, emerged as the best catalyst of the overall series to convert aziridines with smallN-alkyl substituents into the corresponding 5-aryl-oxazolidin-2-ones

    Integrating Optical Wireless Communication Into an Optical Bifocal Metrology for Aerospace

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    Recently an innovative bifocal optical metrology method was proposed for space applications (e.g., rendez-vous and docking), based on unmodulated white LEDs. Here we design, realize, and test a solution that upgrades the metrology to include a digital communication feature, with no modification of the optical elements of the original system: indeed, the scheme exploits the same optical sources that are needed for metrology, which are now also working as optical antennas as their intensity is now modulated. At the receiver side, the conventional camera is now sided by a common photodiode. The system provides unidirectional data communication at 10 kbit/s speed. It is designed to support manoeuvres up to 400 m distance. The lab tests confirm the effectiveness of the proposed solutions, showing correct data transfer without any noticeable degradation of the metrology system

    Promotion of E-bikes for delivery of goods in European urban areas: an Italian case study

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    The paper presents the first results of some tasks of Pro-E-Bike, an Intelligent Energy Europe (IEE) funded project, started on March 2013 ending in February 2016. Pro-E-Bike promotes clean and energy efficient vehicles, analyses the performance of electric bicycles and electric scooters (Light Electric Vehicle, LEV) for the delivering of goods in urban areas and tests the use of these vehicles in seven European countries with twenty five companies, both delivering ones and companies that deliver their own products. Pilots will enable the demonstration of measurable effects in terms of reduction of CO2 emissions and energy savings in urban transport: related data about environmental, economic and social effects resulted by the introduction of e-bikes and e-scooters in the pilot cities will be collected. The paper will give an overlooks of the Italian pilot, that will take place in Genova, describing the subjects involved and the expected results

    Effects of the current financial and economic crisis on the rural landscape as well as the agri-food sector in Europe and Central Asia

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    This paper reviews the expected effects of the current financial crisis and subsequent recession on the rural landscape, in particular the agri-food sector in Europe and Central Asia (ECA) on the basis of the structure of the rural economy and of different organisations and institutions. Empirical evidence suggests that the crisis has hit the ECA region the hardest. Agriculture contributes about 9% to gross domestic product (GDP) for the ECA region as a whole with 16% of the population being employed in the agricultural sector. As far as the impact of the financial crisis on the agri-food sector is concerned, there are a few interconnected issues: (1) reduction in income elastic food demand and commodity price decline, (2) loss of employment and earnings of rural people working in urban centres, implying also costly labour reallocation, (3) rising rural poverty originating mainly from lack of opportunities in the non-farm sector and a sizable decline of international remittances, (4) tightening of agricultural credit markets, and the (5) collapse of sectoral government support programs and social safety-net measures in many countries. The paper reveals how the crisis hit farming and broader agri-business differently in general and in the ECA sub-regions

    Synthesis of α-alkylidene cyclic carbonatesviaCO2fixation under ambient conditions promoted by an easily available silver carbamate

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    The simple and cost-effective compound [Ag(O2CNEt2)], in combination with PPh3, works as an effective catalytic precursor in the carboxylation of propargyl alcohols at ambient temperature and atmospheric CO2pressure, and in most cases under solventless conditions. The silver carbamate revealed a better performance than commercial silver oxide, Ag2O, and allowed to obtain a series of α-alkylidene cyclic carbonates in high yields

    Measurement of transfer of colostral passive immunity in dairy calves

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    The administration of high quality colostrum reduces preweaning morbidity, mortality and, therefore, economic losses related to replacement animals. It also stimulates and improves calf growth, increasing milk production and longevity of the future dairy cows. The aim of the present study was to evaluate the influence of breed and parity of the dam on colostrum quality, and of breed and gender of the calf, and time from calf birth to the administration of the first colostrum meal on the transfer of passive immunity to the calf by the field test of the Failure of Passive Transfer (FPT) on calf serum. A further objective was to improve the diagnostic accuracy of the field FPT test through a second laboratory phase improving the turbidity evaluation. The amount of IgG fed to calves (IgG concentration multiplied by the volume of colostrum administered) was influenced by dam parity as significant differences (P < 0.05) were detected between first- and fourth-parity cows, and between second- and fourth-parity cows. The administration of good quality colostrum (IgG > 50 mg/ml) between 5 and 9 h of life was able to reduce the risk of FPT more effectively than the administration performed within the first 4 h of life. However, further studies on larger sample size is needed to confirm the present findings. The spectrophotometric measurements confirmed the results obtained by the field turbidity test at 14% sodium sulphite dilution. It would be interesting in future to expand the dataset and validate the spectrophometric method
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