Journal of Scientific & Industrial Research

VOLUME 61

                                   NUMBER 9

SEPTEMBER 2002

CONTENTS

Review Papers

667

From content-based to connectivity-based search on the world wide web: a journey trail
















M M Sufyan Beg

In searching the World Wide Web all-and-only relevant documents in a ranked order are desired in response to a query. The search with the classical content-based information retrieval techniques are popular. The commercial pressure, and spamming are major threats to facing the content-based techniques. The hypertextual structure of the web was also exploited. The number and quality of hyperlinks to a page has been taken as a measure of authority of that page. A page will be more authoritative if many pages point to it, or if some high-authority pages point to it. The authoritative value may be a basis for ranking of pages. This approach tackles spamming as the importance of a page would be determined by the hypertextual contents of other pages on the web in addition to the contents of that page which gives an unbiased factor to the ranking procedure. Hypertextual structure has proved useful in finding related pages. It also helps in situations where formulation of a query is difficult, particularly when the information space is unfamiliar to the user. If the web is seen as a directed graph, with web pages as nodes and the hyperlinks between them being as edges of the graph, then starting from a sample page, the breadth-first search to a few levels would point to a set of pages that are very much related to the sample page.

680

Melt/solution processable polyaniline and blends






























Raji K Paul & C K S Pillai

Conducting polyaniline (PANI) has important electrical, electrochemical and optical properties, with environmental stability. Want of suitable methods of preparation stand in its way to commercial exploitation. A number of strategies have been discussed for preparing melt/solution processable PANI, the processability of which has been a great concern till recently. Doping with functionalised dopants, and blending with thermoplastics are being widely adopted. Functionalised dopants possessing plasticising cum protonating abilities, synthesized from naturally existing materials, are also promising. Thus, the use of functionalised dopants possessing plasticising cum solubilizing cum protonating abilities could be of value in preparing melt/solution processable blends of thermoplastics/elastomeric polymers with PANI.

 

CONTENTS

Review Papers

690

A review on microbial alkaline proteases





P Ellaiah, B Srinivasulu & K Adinarayana

Describes the proteases that can resist extreme alkaline environments produced by a wide range of alkalophilic microorganisms. Different isolation methods which enable the screening and selection of promising organisms for industrial production are discussed. The various nutritional and environmental parameters affecting the production of alkaline proteases are delineated. The production of proteases by free and immobilized whole cells is discussed. The purification, properties, and applications of these protease are also discussed.

Papers

705

Corrosion of coated cast iron in aqueous solutions

















Rita Mehra & Aditi Soni

The effectiveness of various coatings and their combination on cast iron is studied under various experimental conditions, like period of immersion, temperature, and flow velocity of corrosive medium, using weight loss and potentiostatic polarization measurements. Hot galvanized coating (HGC) is found to provide better protection than cold galvanized coating. Half-coated specimens are corroded more and therefore are not suitable for use in water supply systems.

712

Surface parameters and corrosion inhibition of some isothiouranium derivatives
























S T Keera, N A Negm, S M Ahmed &
A M Badawi

Four alkyl isothiouronium halide compounds in which the alkyl groups are dodecyl, hexadecyl, and octadecyl, respectively, are prepared. The measured surface tension at various concentrations as aqueous solutions of each of these compounds at various temperatures enables the calculation of surface and thermodynamic parameters. The critical micelle concentrations of these compounds decreases with increase in temperature. The calculated free energy changes for micelle formation and adsorption of these compounds shows that these processes are spontaneous in nature. The corrosion inhibition properties of these compounds for mild steel in sulphuric acid as determined through potentiodynamic polarization measurements, indicates that dodecyl isothiouronium bromide exhibits better inhibitor efficiency than its higher homologues. For the same compound studied the iodide salt gives a better inhibitor efficiency than the bromide.

CONTENTS

Papers

719

Chemical and  biochemical degradation of waste cellulosic materials









A M El-Masry, M F Ghaly,
M A Khalafallah & Y A El-Fayed

Some of the agricultural wastes, such as pith bagasse, rice husk and corn maize are subjected to both chemical and biochemical degradation. Different acid concentrations as well as the cellulase-producing microorganisms are tested. Comparative studies between the chemical hydrolysis and enzymatic degradation, for the selected cellulosic materials, are discussed. Results indicate that the optimum conc. of HCl, which gives the highest yield of reducing sugars from the used cellulose materials is 5 per cent. Byproducts formed by acid degradation rather than the raw materials. Screening of cellulase producing-organisms in the soil, show that actinomycetes and fungi are predominant. The most efficient fungal isolated is identified as Aspergillus ochraceous. Occurrence of free reducing sugars in the growth medium as well as prolonged incubation times, both drastically affect cellulase(s) yield. Reduction in sugar content and cellulose remaining are found to be inversely proportional.

726

A low cost device for production of country roofing tiles





























S K Handa & C L Verma

A low cost moulding device for production of compact country roofing tiles is designed and fabricated at Central Building Research Institute (CBRI), Roorkee. Extensive trials have proven its amenability to commercialization for production rate of 500-600 tiles/d by a semi-skilled worker. The details of the low cost device for production of country roofing tiles are delineated.

729

Comparison of fixation characteristics of new acid fixing reactive dyes derived from
5, 10-phenophosphazine ring with
commercial reactive dyes on nylon 66 and wood substrates






A Mamuda, K A Bello & M K Yakubu

The traditional alkaline reactive dyes are found unsuitable  for the continuous dyeing of the polyester/cotton blends. This and other problems lead to the search for the acid fixing reactive dyes. Calcobond and Procion T dyes are thus introduced. However, these series of dyes have suffered diminishing acceptability because of the expensive application conditions. Dyes are accidentally found to form covalent bonds with cellulose at neutral pH. Application of dyes derived from the 5,10-phenophosphazine ring to wool and nylon substrates is reported. The effect of pH on exhaustion and fixation is investigated. The kinetics of dyeing is also studied and compared with some commercial alkaline fixing reactive dyes. The dyes are established to be acid fixing on wool and nylon. A reaction mechanism is also proposed.

CONTENTS

Conference Report

734

Second international conference on plants and environmental pollution (ICPEP-2) — a report


Anil K Gauniyal & J K Johri

 

Book Reviews

743

·          Bioinformatics — the machine learning approach
      Reviewer: A Krishnamachari

 

·          Sustainable human ecology
      Reviewer: S Mohan

 

·          Small business and industry — a handbook for entrepreneurs
      Reviewer: N Mrinalini

Sci-Tech Update

747

·          Knowledge is more important than petroleum

 

·          Could fuel cells be the alternative energy

 

·          Life in a hostile universe

 

·          Klez: the most virulent e-mail virus

 

·          Software engineering on internet time and with agent components

 

·          Super-secure Linux

 

·          Phone chips could provide instant warning of bioattacks

 

·          New showcase on environmental projects on CORDIS

 

·          Catalyst reduce emissions

 

·          Organic polymer developed

 

·          Newly isolated microorganisms clean hazardous wastes

 

·          Machete – an enzyme from bacteria that help nerves regrow

 

·          Stem cells do their stuff for Parkinson’s patient

 

·          Chemicals cocktails make a potent mix

766   Additions and Corrections