Synthesis of novel tri- and tetrasubstituted C<Subscript>18</Subscript> furan fatty esters

A methylene-interrupted C₁₈ keto-acetylenic fatty ester (methyl 12-oxo-9-octadecynoate) was obtained from methyl ricinoleate by bromination-dehydrobromination followed by oxidation. Reaction of methyl 12-oxo-9-octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide furnished methyl 8-[5-hexyl-3-allyl-furan-2-yl]-octanoate (1, 56%) or methyl 8-[5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (2, 55%). Reaction of methyl 12-oxo-11-chloro-or 11-fluoro-9-octadeyynoate (prepared from methyl santalbate-methyl 11-E-9-octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (3, 50%) or methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (4, 50%), respectively. And when methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide, the reaction yielded tetrasubstituted C₁₈ furan derivatives, viz, methyl 8-(3-allyl-4-chloro-5-hexyl-furan-2-yl)-octanoate (5, 54%), methyl 8-[4-chloro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl)-octanoate (6, 54%), methyl 8-(3-allyl-4-fluoro-5-hexyl-furan-2-yl]-octanoate (7, 10%), and methyl 8-[4-fluoro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the ¹³C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.     

Nutritional constituents and antioxidant properties of indigenous kembayau (Dacryodes rostrata (Blume) H. J. Lam) fruits

The nutritional and antioxidant properties of peels, pulp and seeds of kembayau (Dacryodes rostrata) fruits were evaluated. Kembayau seeds and pulp were rich in fat, while peels had the highest ash contents. Potassium was the most prevalent mineral in peels (380.72-1112.00 mg/100 g). In kembayau fruits, total flavonoid content (1012.74-28,022.28 mg rutin equivalent/100 g) was higher than total phenolic and total monomeric anthocyanin contents. Kembayau seeds exhibited high flavonoid and phenolic contents compared to the contents in peels and pulp. Antioxidant capacities were also higher in seeds as typified by trolox equivalent antioxidant capacity assay (51.39-74.59 mmol TE/100 g), ferric reducing antioxidant power assay (530.05-556.98 mmol Fe²⁺/100 g) and by 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity (92.18-92.19%) when compared to peels and pulp. Pulp and peels of kembayau fruit may be an important source of energy and minerals for human consumption, while seeds have a good potential as antioxidants.     

Application of Matrix Solid-Phase Dispersion and Liquid Chromatography–Ion Trap Mass Spectrometry for the Analysis of Pesticide Residues in Fruits

This study presents an application of rapid and sensitive multiresidue method for the analysis of acephate, acetamipride, atrazine, carbendazim, carbaryl, carbofuran, dimethoate, imidacloprid, linuron, malathion, monocrotophos, monuron, propazine, simazine, and tebufenozide in fruits. The method involves an extraction procedure based on matrix solid-phase dispersion using diatomaceous earth as a dispersant and dichloromethane as the eluent. The target pesticides were determined using liquid chromatography–ion trap mass spectrometry. Quantification of the analytes was carried out using the most sensitive ion transition. Ion trap parameters, like activation q and time, were found to have a prominent influence on method sensitivity for some pesticides and they were optimized accordingly. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional ion transitions besides the ones used for quantification. The method was validated for accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as the relative standard deviation, was in general lower than 20 %. The applicability of the method to routine analysis was tested in real fruit samples with good performance.     

Study of Low-Temperature Thermocompression Bonding in Ag-In Solder for Packaging Applications

Low-temperature solders have wide applications in integrated circuits and micro-electromechanical systems packaging. In this article, a study on Ag-In solder for chip-to-chip thermocompression bonding was carried out. The resulting joint consists of AgIn₂ and Ag₉In₄ phases, with the latter phase having a melting temperature higher than 400°C. Complete consumption of In solder into a Ag-rich intermetallic compound is achieved by applying a bond pressure of 1.4 MPa at 180°C for 40 min. We also observe that the bonding pressure effect enables a Ag-rich phase to be formed within a shorter bonding duration (10 min) at a higher pressure of 1.6 MPa. Finally, prolonged aging leads to the formation of the final phase of Ag₉In₄ in the bonded joints.     

Implementation of Two-Dimensional Polycrystalline Grains in Object Oriented Micromagnetic Framework

In response to the growing need for a more accurate micromagnetic model to understand switching phenomenon in nanoscale magnets, we developed the capability to simulate two-dimensional polycrystalline grains using the Object Oriented Micromagnetic Framework (OOMMF). This addition allows users full flexibility in determining the magnetocrystalline anisotropy and axe in each grain as well as the inter- and intragranular exchange coupling strength.     

Analysis of Echoes in Single-Image Random-Dot-Stereograms

Three-dimensional depth information of a surface can be encoded in a two-dimensional image called autostereograms. The encoded surface can be reconstructed from an autostereogram by using the correspondences between pixels in human brains or computer algorithms. However, in some cases, the reconstructed surface is not unique because of echoes. In the presence of echoes, reconstruction of the original surface from the autostereogram cannot be guaranteed since no cue of the original surface is available in autostereograms. In this paper, the causes of echoes are investigated and conditions for echo-free reconstruction are derived. Based on these conditions, autostereogram generation algorithm is revised to guarantee echo-free autostereograms. Besides, the surface reconstruction algorithm is modified such that original surfaces encoded are always reconstructed from echo-free autostereograms.     

Design of a RFID case-based resource management system for warehouse operations

In the past, the selection of resources to execute various warehouse operation services was done solely by experts. In this paper, a RFID-based Resource Management System (RFID-RMS) is designed to help users to select the most suitable resource usage packages for handling warehouse operation orders by retrieving and analysing useful knowledge from a case-based data warehouse for solutions in both time saving and cost effective manner. In addition, a pure integral-linear programming model using a branch and bound algorithm to define the optimum travel distance of forklifts is also developed and embedded in the proposed system. The proposed system, which is suitable for usage in a warehouse operation environment, enhances the effectiveness in formulating resource usage package and managing resource operation by integrating the Radio Frequency Identification (RFID), case-based reasoning (CBR) technologies and the programming model for forklift route optimization. Through applying RFID-RMS in the GENCO Distribution System, a multinational logistics company, the utilization of warehouse resources is expected to be maximized while work efficiency will be greatly enhanced.     

Automatic generation of artistic chinese calligraphy

Chinese calligraphy is among the finest and most important of all Chinese art forms and an inseparable part of Chinese history. Its delicate aesthetic effects are generally considered to be unique among all calligraphic arts. Its subtle power is integral to traditional Chinese painting. A novel intelligent system uses a constraint-based analogous-reasoning process to automatically generate original Chinese calligraphy that meets visually aesthetic requirements. We propose an intelligent system that can automatically create novel, aesthetically appealing Chinese calligraphy from a few training examples of existing calligraphic styles. To demonstrate the proposed methodology's feasibility, we have implemented a prototype system that automatically generates new Chinese calligraphic art from a small training set.     

Low complexity Byzantine-resilient consensus

The application of the tolerance paradigm to security - intrusion tolerance - has been raising a reasonable amount of attention in the dependability and security communities. In this paper we present a novel approach to intrusion tolerance. The idea is to use privileged components - generically designated by wormholes - to support the execution of intrusion-tolerant protocols, often called Byzantine-resilient in the literature.The paper introduces the design of wormhole-aware intrusion-tolerant protocols using a classical distributed systems problem: consensus. The system where the consensus protocol runs is mostly asynchronous and can fail in an arbitrary way, except for the wormhole, which is secure and synchronous. Using the wormhole to execute a few critical steps, the protocol manages to have a low time complexity: in the best case, it runs in two rounds, even if some processes are malicious. The protocol also shows how often theoretical partial synchrony assumptions can be substantiated in practical distributed systems. The paper shows the significance of the TTCB as an engineering paradigm, since the protocol manages to be simple when compared with other protocols in the literature.Published online: 29 October 2004This work was partially supported by the EC, through project IST-1999-11583 (MAFTIA), and by the FCT, through the Large-Scale Informatic Systems Laboratory (LASIGE) and projects POSI/1999/CHS/33996 (DEFEATS) and POSI/CHS/39815/2001 (COPE).