Search results

Compilation of numeric data has been of interest to mankind since ancient times. Collections of astronomic observations permitted the production of systematic calendars for great nations like the Mayans, Egyptians, Babylonians and Jews. Extensive sets of data were available to early navigators and pioneer physicists of medieval times. A well known example of data compilation was the celebrated Alfonsine Tables. The tables were completed in 1252 under the direction of Isaac ben Said and Yehuda ben Moshe Cohen during the rule of Alfonso X. of Castile. For three hundred years this was considered to be the best planetary data collection. Another famous astronomical data compilation was Caroline Herschel's Catalogue of Stars published in 1798. In the last decade there has been an increased need for precise information by government agencies, private industries, the business world and academic institutions. The continuing acknowledgement of the need for quantitative data contributed to the quick development and marketing of many databases that contain numerical and other factual information.

At all times engineers have needed to know something of the properties of materials, but of late for a reason that is new. The materials of the nineteenth century were lew and traditional: brick and stone, timber, wrought and cast iron, copper and its alloys with zinc and tin, all these had been used for generations, their properties were familiar, and machines had changed the tempo rather than the methods of their fabrication. Mild steel came to replace wrought iron in structural work. Steel castings were found, for certain purposes, preferable to castings in iron. Reinforced concrete showed how the merits of two materials could be combined. But the engineer, though quick to accept and use these novelties, still maintained his traditional attitude. Only in recent years, by the work of the chemist and the physicist, has his successor been given glimpses of a future in which his problems of fabrication will be solved (the italics are Dr. Houwink's) by the deliberate synthesis of materials with definite clastic and plastic properties. Already his list of constructional materials is lengthened by the addition of plastic resins, cellulose and protein products, artificial rubbers: what is more significant, the macroscopic studies of the nineteenth century (only towards its close was the microscope employed for the elucidation of finer structure) have been largely superseded by methods incomparably more refined, in which the individual crystal as unit is replaced by the complex molecule, the crystalline micro‐structure by the crystal lattice as revealed by X‐rays. We are passing, in materials, from an age of acceptance to an age of control, and henceforth engineering will demand a knowledge of materials both wider and deeper than what sufficed before the War.

This work aims to synthesize a series of novel acyclic and/or heterocyclic systems, as precursors for dyes with potential antimicrobial activity that could be used for simultaneous dyeing and antimicrobial textile finishing. Thus, a series of novel pyridine, thiophene and pyrazolo[3,4-b]pyridine derivatives were synthesized, and their antimicrobial and textile finishing properties were studied and evaluated.

The synthesis, structure elucidation and antimicrobial activities of the newly synthesized compounds based on 4,4-dicyano-3-phenyl-but-3-enoic acid phenylamide (1) were demonstrated. The minimal inhibitory concentration in μg/mL of the compounds showed significant antimicrobial activity against most of the tested organisms. On the other hand, their spectral characteristics and fastness properties were measured and evaluated. Antimicrobial activities of the dyed fabrics in terms of inhibition zones (mm) were measured and evaluated.

A series of novel heterocyclic compounds (Schemes 1-3) were synthesized based on starting material (1). Compounds (1), 2, 4a, 8a and 9c exhibited comparable or even higher antibacterial activities than the selected standards (ampicillin), while compounds 2, 3c, 3d, 4a and 8b revealed higher antifungal activities than the selected standard (cycloheximide). On the other hand, some dyes showed high antimicrobial evaluation on the dyed fabrics (nylon 66, acetate and polyester) expressed as size (mm) of inhibition zones (Tables I-IV).

Results revealed that many hydrazo and azo derivatives were synthesized from some pyridines and thiophenes. The antimicrobial evaluation and textile finishing of the newly synthesized products revealed significant and potent values of antimicrobial activity.

All the synthesized compounds were novel and most of them exhibited higher antimicrobial activities than the selected standards antibiotics, thus are valuable for simultaneous dyeing and antimicrobial functional finishing of textile fabrics.

Success in research – or ‘mastery’ as we call it – can lead to interdisciplinarity arising among the increasingly fragmented disciplines of science: researchers in molecular biology can be assisted by advances in the physics of atomic imaging, when they become aware of a development's potential and feel motivated to take advantage of it. The unpredictability of advances in scientific research makes the location and nature of interdisciplinarity largely unpredictable. This unpredictability means that organisational structures in which scientific research takes place – and in which our students are trained – are likely to lag behind interdisciplinary synergies developing in the laboratory. The lag time suggested by our model explains the challenges faced by leaders of interdisciplinary programmes in higher education. One can conclude that opportunities for interdisciplinarity in science are held back by discipline-bound institutions.

Information exchange is of primary importance in any scientific discipline but particularly so in such an information‐rich domain as chemistry. Chemists have developed a language of their own for representing information which is essentially graphical in nature: structure diagrams and reaction equations. Methods of converting this graphical language into a computer representation have been developed and efforts have been made to standardise such representations. This paper reports on these achievements and points out where further work has to be done.

The purpose of this paper is to synthesise, characterise and find out properties of some new bifunctional reactive azo dyes using pyrazolo[1,2‐a]pyrazole 3‐carboxylic acid fused systems as the chromophoric moiety, bearing good colour strength, lightfastness, and other favourable properties.

The dyes are synthesised by diazotisation, coupling and cyclisation reactions. Firstly, synthesised 4‐arylazo‐1,5‐dioxopyrazolo[1,2‐a]pyrazole 3‐carboxylic acid chromophoric moieties and coupled with diazonium salts having the aforementioned reactive groups, thus yielding the new target reactive. The synthesised dyes were applied to cotton and wool fabrics under the typical exhaust dyeing conditions and their dyeing properties were investigated. The structures of these dyes are characterised and confirmed by melting point, elemental analysis, infrared, ultraviolet‐visible spectroscopy (UV/VIS) and nuclear magnetic resonance (1H‐NMR) data.

The wavelength of maximum absorptions, molar extinction coefficients are strongly dependent on the electron donating ability of the substituents on the coupling moiety. The absorption bands of these dyes move towards longer wavelength as the polarity of the solvents and electron density of substituents on the coupling moiety increase. The dyes applied on cotton and wool showed higher exhaustion and fixation values, colour yields and fastness properties.

The method developed provided a simple producing fused pyrazolo[1,2‐a]pyrazole disazo chromophoric systems based on 4‐arylazo‐1,5‐dioxopyrazolo[1,2‐a]pyrazole 3‐carboxylic acid as well as reactive dyes applied on wool and cotton dyes.

In this paper, three series of pyrazolo[1,2‐a]pyrazole derivatives dyes are synthesised and characterised. They have not been registered in the literature previously.

The paper describes the plasma polymerisation process for depositing ultrathin films. Such films, deposited from monomers containing hydrophobic elements such as hexafluorobenzene and hexamethyldisiloxane, showed excellent water vapour barrier properties, due to dense, highly crosslinked and rigid structures of the films. The composition and structure of the plasma polymerised films have been elucidated by ESCA and infra‐red spectroscopy.

This study is aimed to develop a novel intuitionistic fuzzy P-graph with Gaussian membership function to help decision-makers deal with complex process network systems.

Two fuzzy P-graph case studies of the cogeneration system were selected, and relevant data were collected, including the structure and flow sequence of the system, and the rate of material and product transitions between the operating units. Gaussian function membership was set according to the restriction of fuzzy upper and lower bounds. Then the α-cut was used to obtain different upper and lower bound restrictions of each membership degree. After finding the optimal and suboptimal solutions for different membership degrees, the results of non-membership and hesitation were calculated.

The proposed method will help the decision maker consider the risk and provide more feasible solutions to choose the optimal and suboptimal solutions based on their own or through experience. The proposed model in this study has more flexibility in operation and decision making.

This study is the first to propose a novel intuitive fuzzy P-graph and demonstrates the effectiveness and flexibility of the method by two case studies of the cogeneration system. However, the addition of hesitation can increase the error tolerance of the system. Even for the solutions with a high degree of membership, optimal and suboptimal solutions still exist for the decision maker to select. Since decision makers expect the higher achievement of the target requirements; thus, it is important to have more feasible solutions with a high degree of membership.

This paper aims to synthesise, characterise and find out the properties of a model dye for convenient union dyeing of wool, polyester and wool/polyester blend fabric compared with C.I. Disperse Yellow 23. The reactive disperse dye was prepared containing sulphatoethylsulphone (SES) as a reactive group. The dye was synthesised by diazotization and coupling reaction. Firstly, we synthesized azo dye intermediate I using 1-aminobenzene-4-sulphatoethylsulphone diazotized and then coupled it with aniline. The synthesized azo dye intermediate I was diazotized and coupled with phenol to give dye 2. Different factors affecting the dyeability and fastness properties of SES dye 2 were thoroughly investigated on wool, polyester and wool/polyester blend fabrics in comparison with C.I. Disperse Yellow 23 dye 1. Maximum exhaustion and total fixation yield using sulphatoethylsulphone (SES) dye 2 were achieved on wool fabric at neutral pH 7. The dye showed high dyeing performance due to its nonionic reactive VS derivative. The dyeing results indicate high quality dyeing properties

This is a description of the first stage of an attempt to improve a thesaurus by providing it with new terms derived by computer analysis of semantic proximity between concepts from a large file of 20,000 documents. At the first stage the semantic proximity between concept and core words was established on the level of a set of higher complexity. This set is defined when making the qualitative and quantitative choice of the concepts capable of being grouped into classes. The second stage will be the classification of terms belonging to that coherent set by clustering.