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1 – 10 of over 20000
Article
Publication date: 7 June 2013

L. Rickenbacher, T. Etter, S. Hövel and K. Wegener

Selective laser melting (SLM) is being investigated by Alstom and IWF due to its flexibility, cost‐ and lead‐time reduction potential for reconditioning of hot gas path…

3763

Abstract

Purpose

Selective laser melting (SLM) is being investigated by Alstom and IWF due to its flexibility, cost‐ and lead‐time reduction potential for reconditioning of hot gas path components used in today's heavy‐duty gas turbines. This paper aims to address this issue.

Design/methodology/approach

Tensile tests as well as relaxation and creep tests were carried out to assess SLM processed IN738LC for use in high temperature applications. To evaluate potential anisotropic material behaviour resulting from the layer‐wise build up process, all specimens were built in two directions: parallel and perpendicular to the build direction, respectively. Furthermore, extensive metallurgical investigations were made to analyse the chemical homogeneity as well as the correlation between microstructure and high temperature properties of SLM processed IN738LC.

Findings

Tensile tests showed that strength properties superior to cast IN738LC can be achieved by processing this material by SLM alternatively. Due to differences in grain size, grain orientation as well as γ′size and morphology the relaxation behaviour of SLM specimens is inferior compared to cast material. However, creep tests have shown that values within the lower scatter band of cast material can still be achieved along the build direction.

Originality/value

Very limited knowledge exists regarding the processing of γ′precipitation‐strengthened nickel‐base superalloys by SLM and the resulting high temperature material properties. Layered manufacturing and any lack‐of‐fusion porosity influences them as well as high temperature gradients, occurring during the process. This article presents the latest insights from material testing of selective laser molten IN738LC at elevated temperatures.

Article
Publication date: 31 July 2009

Chien‐Yi Huang, Ming‐Shu Li, Chen‐Liang Ku, Hao‐Chun Hsieh and Kung‐Cheng Li

The purpose of this paper is to discuss the chemical characterization of failures and process materials for microelectronics assembly.

Abstract

Purpose

The purpose of this paper is to discuss the chemical characterization of failures and process materials for microelectronics assembly.

Design/methodology/approach

The analytical techniques used for chemical structures and compositions including Fourier transform infrared spectrometer (FTIR), scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy are conducted.

Findings

The residues on the golden finger are identified to be the flux used in the assembly processes. Besides, the contaminants on the processed and incoming connector pins are verified to be polyamides (–CONH functional groups) from housing material's residue. Three liquid fluxes used in wave soldering are analyzed by their chemical structure. One flux showing the OH groups at 3430 cm−1 indicates higher acid contents. This consists with the acidic values specified by the supplier. Also, the solder mask under study has ever appeared peeled‐off issue. The FTIR spectra results indicated 62.2 percent degree of curing while vendor's spec is above 70 percent.

Originality/value

The establishment of the Infrared spectra database for fluxes and process materials help determine the root cause of the contaminants to reduce re‐occurrence of similar problems and thus enhance the manufacturing capability. The infrared spectrophotometry technique can be used by professional original design manufacturing and/or electronics manufacturing service, providers to investigate board/component defects during product pilot run stage and volume production.

Details

Microelectronics International, vol. 26 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 May 1965

B.E. HOLM

The Institution of Chemical Engineers sponsored this series of lectures on the information programmes of the American Institute of Chemical Engineers, the Engineers Joint…

Abstract

The Institution of Chemical Engineers sponsored this series of lectures on the information programmes of the American Institute of Chemical Engineers, the Engineers Joint Council, and other organizations of interest to those in science and technology. The Institution has been interested in these developments and wants to assess what role it should play in the processing of technical information. From the trends of these organizations and from the developments in equipment and microforms patterns are emerging which will help the information officer in his work.

Details

Aslib Proceedings, vol. 17 no. 5
Type: Research Article
ISSN: 0001-253X

Article
Publication date: 11 September 2007

V. Dunkwal, S. Jood and S. Singh

This article aims to focus on the food value of the mushroom. Because of its low calorific value and very high content of proteins, vitamins and minerals, mushrooms may…

1003

Abstract

Purpose

This article aims to focus on the food value of the mushroom. Because of its low calorific value and very high content of proteins, vitamins and minerals, mushrooms may contribute significantly in overcoming protein deficiency in developing countries like India.

Design/methodology/approach

Oyster (Pleurotus sajor caju) mushroom cultivated on two substrates i.e. wheat straw and brassica straw were procured. Freshly harvested and washed mushrooms were cut into small pieces. Sliced mushrooms were divided into four portions. Two portions were left untreated and dried using sun and oven drying methods. The third portion was blanched in boiling water at 100 °C for two mins, cooled immediately and drained. The blanched samples were divided into two portions. One portion was sun dried and another was oven dried. The fourth portion was soaked in solution of citric acid (0.25 percent) for 30 mins and drained. The steeped samples were divided into two portions. One portion was sun dried and another was oven dried. Each sample was dried from initial moisture content of 91 percent on fresh weight basis of the final moisture content 10 percent on dry weight basis. All the samples were ground to make fine powder. The untreated and treated samples were analysed for physico‐chemical properties and sensory evaluation by using standard methods.

Findings

Treated and untreated powders prepared from oyster (Pleurotus sajor caju) mushrooms grown on two substrates i.e. wheat and brassica straw were analysed for physical and chemical characteristics. Among the powders, T6 (steeped in 0.25 percent citric acid and oven dried) powder exhibited highest yield followed by untreated and blanched powders. On the other hand, untreated samples T1 (sun dried) and T4 (oven dried) showed higher browning index as compared to pretreated powders. Steeped samples (T3 and T6) from both type of mushrooms, irrespective of drying methods exhibited higher values of water retention capacity and swelling index as well as sensory attributes (colour, aroma and texture) In terms of chemical analysis, steeped samples from both types of mushrooms, irrespective of drying methods, exhibited higher contents crude protein, crude fibre and ash as compared to blanched powders. Blanching in hot water may cause leaching out of nutrients.

Practical implications

With regard to healthy benefits and medicinal value of mushroom, its production and consumption should be increased. However, mushroom production does not demand land, but helps in the bioconversion of potential pollutants like agro‐wastes to useful and nutritive food for human consumption, which is essential to a developing country like India.

Originality/value

The findings of this article may contribute significantly in overcoming protein deficiency in developing countries like India. Mushrooms have a low carbohydrate content, no cholesterol and are almost fat free. Therefore, they form an important constituent of a diet for a population suffering from atherosclerosis.

Details

British Food Journal, vol. 109 no. 9
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 6 January 2012

Teofil Jesionowski, Magdalena Nowacka and Filip Ciesielczyk

The purpose of this paper is to characterise the electrokinetic properties of pigments supported on both unmodified and modified silica. The paper describes the…

Abstract

Purpose

The purpose of this paper is to characterise the electrokinetic properties of pigments supported on both unmodified and modified silica. The paper describes the preparation of hybrid pigments via adsorption of organic dyes on silica supports and determination of the zeta potential and electrophoretic mobility of the materials obtained.

Design/methodology/approach

The materials studied were hybrid pigments obtained as a result of adsorption of two basic dyes: C.I. Basic Red 1 and C.I. Basic Orange 14 and one acidic dye C.I. Mordant Red 3 from solutions of concentrations of 500, 2,000 and 3,000 mg/dm3 on the surface of both unmodified and modified silica supports. The agent used for modification of the silica surface was N‐2‐(aminoethyl)‐3‐aminopropyltrimethoxysilane.

Findings

The modification of the silica surface with aminosilane was found to change, significantly, the electrokinetic character of the inorganic support. This change was interpreted as being due to the ionisation of −NH2 groups from the modifier molecule, which changes the surface charge. Electrokinetic curves of the pigment composites changed considerably as a function of the type and concentration of the organic dye adsorbed.

Research limitations/implications

Only SiO2 supports (unmodified and aminosilane‐grafted) and C.I. Basic Red 1, C.I. Basic Orange 14 or C.I. Mordant Red 3 dyes adsorbed on its surface were evaluated. Other dyes could also be studied.

Practical implications

Measurements of the zeta potential were used to characterise the stability of colloidal dispersions of paints or dyes and to control the stability of paints on storage and their performance on painting and drying.

Originality/value

The paper demonstrates that the measurements of zeta potential permit determination of the optimum conditions for the use of a given pigment. The finding of the change of the zeta potential of a given pigment and so, also its application properties as a result of different functional groups in the dye or the modifying agent molecules.

Details

Pigment & Resin Technology, vol. 41 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 11 September 2009

Jianlong Yuan, Zhenhua Gao and Xiang‐Ming Wang

The purpose of this paper is to evaluate the effect of different amounts of sodium hydroxide (NaOH) introduced during the resin synthesis on the properties of

Abstract

Purpose

The purpose of this paper is to evaluate the effect of different amounts of sodium hydroxide (NaOH) introduced during the resin synthesis on the properties of bark‐phenol‐formaldehyde (BPF) adhesives aims at achieving a balance between storage life and other properties of BPF adhesives.

Design/methodology/approach

Based on the best synthetic technologies for the production of BPF adhesives obtained in a previous study, a new synthetic technology is developed for the production of BPF adhesives that involve a three‐step addition of NaOH using different amounts of NaOH in the third charge. Gel permeation chromatography is used to evaluate properties of the phenol‐formaldehyde (PF) and BPF adhesives.

Findings

The amount of NaOH in the third charge has an important influence on many BPF adhesive properties. The paper determines that the synthetic technology involving three‐step NaOH additions with only water introduced in the third charge of NaOH produces a BPF adhesive with the longest storage life and best bonding strength.

Research limitations/implications

BPF adhesives are very complex systems with many unknown variables.

Practical implications

The improved storage life of the BPF adhesive prepared with the new synthetic technology is comparable to that of a commercial PF adhesive, which indicates that this new technology shows greater potential for commercial applications.

Originality/value

A new synthetic technology is developed to produce a BPF adhesive that is more comparable to commercial PF adhesives than other BPF adhesives in terms of storage life and other resin properties.

Details

Pigment & Resin Technology, vol. 38 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 21 June 2011

Imtiaz Ahmad, M. Shakirullah, M. Ishaq, M. Arsala Khan and Jan ullah

The purpose of this paper is to investigate some cheap and highly stable additives to improve the quality of lubricating oil.

234

Abstract

Purpose

The purpose of this paper is to investigate some cheap and highly stable additives to improve the quality of lubricating oil.

Design/methodology/approach

The study was performed using phenol, p‐cresol and pyrogallol as antioxidants. The concentration of each antioxidant was varied between 0 and 1 per cent. Sample (50 ml) blended with the antioxidant was taken in the same trap. The trap was placed on water both maintained at a temperature of 50°C. Air was bubbled for the time duration of 6 h. After 6 h, the contents of the trap were carefully collected and characterized. The oxidation was performed in a specially designed glass made U‐shaped trap in the absence and presence of antioxidants. The trap containing sample was tied with an iron stand. Air was bubbled through the sample. The bubbling was assisted by the suction pump at room temperate (24°C). The sample was aerated for time duration of 6 h. After 6 h, the contents of the trap were carefully collected in a dried bottle for physicochemical tests.

Findings

The results indicate that phenol is the best antioxidant in concentration of 0.5 per cent amongst the three antioxidants used at room temperature as well as at 50°C. Amongst the antioxidants used, the order of suitability is phenol > pyrogallol > p‐creosol.

Originality/value

The antioxidants studied will help increase the service time of the lubricant to save money and to avoid environmental problems arising from careless disposal of used lubricating oils.

Details

Industrial Lubrication and Tribology, vol. 63 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 6 November 2007

S.O. Babalola, O. Taylor, A.O. Babalola and O.A. Ashaye

Yam flour (YMF) is an important staple food in the tropics but its utilization is limited by low nutrient and consumer acceptability. The aim of this paper is to…

351

Abstract

Purpose

Yam flour (YMF) is an important staple food in the tropics but its utilization is limited by low nutrient and consumer acceptability. The aim of this paper is to investigate the effect of substituting yam flour with grain amaranth on chemical and sensory properties.

Design/methodology/approach

YMF and grain amaranth flour (GAF) were prepared on a dry matter basis; GAF was mixed with YMF at ratio 1:3. All flour samples were subjected to chemical (moisture, protein, fat, ash, crude fibre, carbohydrate and minerals) evaluation and sensory evaluation of the stiff gel was conducted by a ten‐member panel consisting of five adult males and five females.

Findings

GAF increased the protein content of YMF significantly at p < 0.05 from 1.8 to 9.63 per cent. There was a decrease in carbohydrate content of YAF when substituted with GAF. There was a significant increase (at p < 0.05) in phosphorus and sodium elements when YMF was substituted with GAF. There was no significant difference in acceptability of gel from grain amaranth and yam flour (GAF–YMF) compared with whole YMF gel on colour, texture, flavour and overall acceptability.

Originality/value

It was apparent that substitution of YMF with GAF improved nutrient composition without affecting the acceptability. This will further improve the nutritional status of people in YMF‐consuming areas.

Details

Nutrition & Food Science, vol. 37 no. 6
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 1 February 2013

B.A. Akinwande, O.A. Abiodun and I.A. Adeyemi

The aim of the study is to compare the effect of steaming method and time on the physico‐chemical properties of underutilized Dioscorea dumetorum with three more commonly…

200

Abstract

Purpose

The aim of the study is to compare the effect of steaming method and time on the physico‐chemical properties of underutilized Dioscorea dumetorum with three more commonly consumed Dioscorea rotundata, Dioscorea cayenensis and Dioscorea alata.

Design/methodology/approach

Raw and pre‐gelatinized flour were produced from the yam species. Pre‐gelatinization was done by steaming diced cubes in autoclave at 68,950 Nm‐2 for 5 min and in Barlett steamer at 98±2°C for 10, 20 and 30 min. Flour samples were analyzed for amylose content, swelling index, consistency, solubility, water absorption capacity, and iodine affinity for starch.

Findings

The physico‐chemical properties of the flours were affected by both species and steaming time. Pre‐gelatinization of the tuber reduced amylose content in all the yam species, which reduced further with increase in steaming time. Except for amylose content and iodine affinity for starch, D. dumetorum compared with D. rotundata and D. cayenensis in the parameters that were measured. Samples autoclaved for 5 min had value similar to those steamed in Barlett steamer for 10 and 20 min for all the parameters that were measured, except consistency.

Practical implications

It is very important to encourage the cultivation and utilization of D. dumetorum because of the high yield and nutritional composition to enhance the nutritional and financial well‐being of the populace.

Originality/value

Pre‐gelatinization is important as pre‐treatment for yam tubers. Underutilized D. dumetorum could be useful in ingredient formulation for product development, especially as a thickening agent.

Details

Nutrition & Food Science, vol. 43 no. 1
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 24 May 2011

Zheng Jin, Yuxi Liu, Xuduo Bai, Xiaomin Ren, Chuanli Qin and Yunhua Wang

The purpose of this paper is to develop a facile method to synthesise nitrogen‐doped carbon aerogels to increase the capacity of supercapacitors.

Abstract

Purpose

The purpose of this paper is to develop a facile method to synthesise nitrogen‐doped carbon aerogels to increase the capacity of supercapacitors.

Design/methodology/approach

Nitrogen‐doped carbon aerogels are prepared as electrode materials through sol‐gel method, using resorcinol, formaldehyde and aniline as raw materials. A series of symmetric supercapacitors are assembled by putting Ni‐MH battery separator between two carbon aerogels electrodes. The electrochemical performances of carbon aerogels and supercapacitors are studied.

Findings

The results show that the optimal molar percentage of aniline in the total molar ratio of resorcinol and aniline is 15 per cent, the mass specific capacitance of which is supposed to be about three times that of RF carbon aerogels. This result could be attributed to the pseudocapacitive effect of nitrogen heteroatoms. Moreover, the nitrogen‐doped carbon aerogels are found to exhibit lower charge transfer resistance at the electrolyte/carbon aerogels interface and lower Warburg impedance.

Practical implications

The supercapacitors can be used in the field of automobile and can solve the problems of energy shortage and environmental pollutions.

Originality/value

For the first time, nitrogen‐doped carbon aerogels are prepared through sol‐gel method, using resorcinol, formaldehyde and aniline as raw materials.

Details

Pigment & Resin Technology, vol. 40 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

1 – 10 of over 20000