CONSTITUENTS OFERYTHRINA SIGMOIDEA

. The study of the secondary metabolites of the chloroform extract of the stem wood of Erythrina sigmoidea afforded a new compound a -sophoradiol (1), and the known compounds: acetate of b -amyrin (2), acetate of oleanolic acid (3), n-isocosanyl-isocosanoate (4), and n-hexatetracontanol (5). Their structures were characterised by spectroscopic methods. (Received February 12, 2001, revised July 3, 2001) Bull.Chem.Soc.Ethiop. 2001, 15(2), 151-15

Melanin production inhibitors from the West African 'Cassipourea congoensis'

Cassipourea congoensis (syn. Cassipourea malosana) is used in African countries as a skin-lightening agent. Two previously unreported cycloartane triterpenoids, 26-hydroxy-3-keto-24-methy lenecycloartan-30-oic acid 1 and 24-methylene-cycloartan-3β,26,30-triol 2 along with the known mahuannin B 3, 7-methoxymahuannin B 4, 7-methoxygeranin A 5, methyl-3-(4-hydroxy-3-methoxyphenyl)-2E-propenoate, glycerol-1-alkanoate, (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal 6, (-)-syringaresinol 7, and stigmast-5-en-3-O-β-D-glucoside, were isolated from the roots of C. congoensis. The crude extract and compounds 1 and 5 were found to inhibit the production of melanin at 10 μM with low cytotoxicity validating the ethno-medicinal use of this plan

Cytotoxic stilbenes and canthinone alkaloids from Brucea antidysenterica (Simaroubaceae)

Phytochemical study of the root and bark of Brucea antidysenterica J. F. Mill. (Simaroubaceae) afforded three new compounds including a stilbene glycoside bruceanoside A (1), and two canthinone alkaloids bruceacanthinones A (3) and B (4), as well as ten known secondary metabolites, rhaponticin (2), 1,11-dimethoxycanthin-6-one (5), canthin-6-one (6), 1-methoxycanthin-6-one (7), 2-methoxycanthin-6-one (8), 2-hydroxy-1,11-dimethoxycanthin-6-one (9), β-carboline-1-propionic acid (10), cleomiscosin C (11), cleomiscosin A (12) and hydnocarpin (13). The structures of all the compounds were determined using spectrometric and spectroscopic methods including 1D and 2D NMR, and HRSEIMS. The identity of the known compounds was further confirmed by comparison of their data with those reported in the literature. The root and bark methanolic extracts, the dichloromethane and ethyl acetate soluble fractions, as well as the isolated compounds (3–13), were assessed for their cytotoxicity against the cancer cell lines A-549, MCF-7 and PC-3. The results suggested that compounds in the extracts might possess a synergic action in their cytotoxicity

Computational analysis of the tip-gap flow of an axial ring fan

This research is focused on the study of the aerodynamic simulation of the flow recirculating through the tip-gap of an axial ring fans normally used in cooling systems of automotive engines. The aerodynamic discomfort behaves like a mechanism that generates acoustic roughness with highly significant effects; so, right out of that generated by the impact of the wake downstream of the rotor on the stator blades, it is one of the most important sources of noise at low frequencies, able to provide tonal and broadband contributions in the spectrum of SPL. This study is developed with a three-dimensional numerical modelling of an axial fan for automotive use through the application of fluid dynamics computational methods CFD. The three-dimensional modelling includes an unstructured grid and a turbulence's modelling based on RANS (Reynolds averaged Navier-Stokes) systems; thanks the commercial code called Star-CCM+ (CD-Adapco) it is possible to solve all the Navier-Stokes equations. Particularly, this study arises in continuity with the sperimental activity done in the aeroacoustic laboratory of DIME whose it is a deepening about aerodynamic deterministic phenomena involved. In fact the geometries reflect those used in the sperimental activity. The aim of this study is deepen the knowledge about the characteristics of the recirculation flow and its interactions with the flow normally evolving in the rotor. In particular the intention is pay attention to the genesis and the following evolution of turbulent structures of large scale which can generate tonal noise when meet the rotor blades

Sistema di pompaggio con pannelli fotovoltaici

la mia tesi si basa sull'idea di utilizzare l'energia solare per far funzionare un sistema motore-pompa solo quando c'è il sole, con lo scopo di prelevare l'acqua da un torrente e utilizzarla per l'irrigazione dei camp

Data collection for port noise monitoring

The impact of noise generated by harbour actives gained a very important role in the last years. While the evaluation of the noise impact of industrial plants and transportation is fully integrated in the activities of noise mapping in urban areas, a lack of regulation exists regarding the activities carried out in ports. The complaints of citizens living close to the harbours pushed the authorities to face the problem. In this context several EU Interreg Maritime research projects have been launched in last few years. Each project is focused on a specific aspect of the problem, but all of them have in common the implementation of a network of sensors aimed to the monitoring of the noise for long periods of time. Such monitoring activity will generate a huge amount of data that must be collected, integrated and stored in a proper database in order to be accessed in a second time. The data can then be used for the management of the harbour (e.g.: by changing the docking position of ships) or to support the decision making in terms of mitigation strategies. In this paper possible ways of storing and managing the data will be described. Keywords: noise monitoring; harbour noise; database; noise pollution; environmental noise