Interplanetary trajectory optimization with swing-bys using evolutionary multi-objective optimization

Interplanetary trajectory optimization studies mostly considered a single objective of minimizing travel time between two planets or launch velocity of spacecraft at the departure planet or maximizing delivered payload at the destination planet. Despite a few studies, in this paper, we have considered a simultaneous minimization study of both launch velocity and time of travel between two specified planets with and without the use of gravitational advantage (swing-by) of some intermediate planets. Using careful consideration of a Lambert's approach with the Newton-Raphson based root finding procedure of developing a trajectory dictated by a set of variables, a number of derived parameters, such as time of flight between arrival and destination planet, date of arrival, and launch velocity, are computed. A commonly-used evolutionary multi-objective optimization algorithm (NSGA-II) is then employed to find a set of trade-off solutions. The accuracy of the developed software (we called GOSpel) is demonstrated by matching the trajectories with known missions

Eco-friendly and versatile brominating reagent prepared from a liquid bromine precursor

Facile bromination of various organic substrates has been demonstrated with a 2 : 1 bromide:bromate reagent prepared from the alkaline intermediate of the conventional bromine recovery process. The reagent is acidified in situ to generate HOBr as the reactive species, which effects bromination. Aromatic substrates that have been successfully brominated under ambient conditions without use of any catalyst include phenols, anilines, aromatic ethers and even benzene. Non-aromatic compounds bearing active methylene group were monobrominated selectively with the present reagent and olefinic compounds were converted into the corresponding bromohydrins in moderate yields. By obtaining the present reagent from the liquid bromine precursor, the twin advantages of avoiding liquid bromine and producing the reagent in a cost-effective manner are realised. When coupled with the additional advantage of high bromine atom efficiency, the present protocol becomes attractive all the way from "cradle to grave"

So1ar Powered Unmanned Surface Vehic1e for Survei11ance

The unmanned surface vehic1e is more popu1ar because of its 1ow cost, f1exibi1ity and a1so it he1ps to reduce the danger to human beings. In this artic1e we describe measurement of environmenta1 monitoring app1ications using integrated sensors and a1so water ph. 1eve1, enemy monitoring using wire1ess camera. So1ar pane1 is used power the mode1. It can f1oat on the water and can a1so run on the surface of earth using servo motor. Using ESP8266 node MCU can send the data to c1oud

So1ar Powered Unmanned Surface Vehic1e for Survei11ance

The unmanned surface vehic1e is more popu1ar because of its 1ow cost, f1exibi1ity and a1so it he1ps to reduce the danger to human beings. In this artic1e we describe measurement of environmenta1 monitoring app1ications using integrated sensors and a1so water ph. 1eve1, enemy monitoring using wire1ess camera. So1ar pane1 is used power the mode1. It can f1oat on the water and can a1so run on the surface of earth using servo motor. Using ESP8266 node MCU can send the data to c1oud

Homocoupling of terminal alkynes catalysed by ultrafine copper nanoparticles on titania

Copper nanoparticles on titania effectively catalyse the oxidative homocoupling of terminal alkynes in the presence of piperidine as a base in tetrahydrofuran (THF) or under solvent-free conditions. A wide range of diynes have been synthesised in high yields using low catalyst loading (1 mol-% Cu). The copper catalyst (mainly as Cu2O) has been characterised by different means, is easy to prepare, can be reutilised several times, works either in air or under inert atmosphere and was shown to be superior to other commercially available copper sources.This work was generously supported by the Spanish Ministerio de Ciencia e Innovación [(MICINN) (grant number CTQ2007-65218) and Consolider Ingenio (grant number 2010-CSD2007-00006)], the Generalitat Valenciana (grant no. PROMETEO/2009/039), and the Fondos Europeos para el Desarrollo Regional (FEDER)

Micellar Promoted Multi-Component Synthesis of 1,2,3-Triazoles in Water at Room Temperature

Micellar media in water provide a simple and efficient environment to favor the multi-component synthesis of 1,2,3-triazoles from organic bromides, sodium azide and terminal alkynes in the presence of [Cu(IMes)Cl] 1 catalyst at room temperature within few hours. The micellar medium favors both the in situ formation of the organic azide and its metal promoted cycloaddition with the alkyneMicellar media in water provide a simple and efficient environment favoring the multi-component synthesis of 1,2,3-triazoles from organic bromides, sodium azide and terminal alkynes in the presence of [Cu(IMes)Cl] 1 catalyst at room temperature within a few hours. The micellar medium favors both the in situ formation of the organic azide and its metal promoted cycloaddition with the alkyne