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Article
Publication date: 26 August 2014

M. Batumalay, A. Lokman, H.A. Rahman, S.W. Harun and H. Ahmad

This paper aims to propose and demonstrate a simple fiber optic sensor using a tapered plastic multimode fiber as a probe for measurement of calcium nitrate concentrations…

Abstract

Purpose

This paper aims to propose and demonstrate a simple fiber optic sensor using a tapered plastic multimode fiber as a probe for measurement of calcium nitrate concentrations in de-ionized water.

Design/methodology/approach

The working mechanism is based on the observed increment in the transmission of the sensor that is immersed in calcium nitrate solution of higher concentration. The tapering of the plastic fiber is carried out by etching method using acetone, sand paper and de-ionized water.

Findings

Tapered fiber with diameter 0.45 mm gives the highest sensitivity of 0.028 mV/% due to better interaction between the evanescent field and the calcium nitrate solution with a good slope linearity of more than 98 per cent for a 1.07 per cent limit of detection in a straight probe arrangement. The use of calcium and nitrate ions within the sensing medium demonstrates the strong dependency of the sensor output trend on the electrolytic nature of the chemical solutions.

Originality/value

Demonstration of tapered plastic multimode fiber sensor probe for measurement electrolytic chemical solutions.

Details

Sensor Review, vol. 34 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 25 January 2011

H.Z. Yang, S.W. Harun and H. Ahmad

The purpose of this paper is to investigate, theoretically and experimentally, a concave mirror‐based fiber optic displacement sensor performance for three‐axes…

Abstract

Purpose

The purpose of this paper is to investigate, theoretically and experimentally, a concave mirror‐based fiber optic displacement sensor performance for three‐axes directional measurements.

Design/methodology/approach

Mathematical model is constructed based on spherical mirror properties of the concave mirror and the simulated result is found to be in good agreement with the experimental results.

Findings

Both theoretical and experimental results show that the focal length and radius of the concave mirror make significant influence to the displacement response. In the x‐axes measurement, six linear slopes are obtained with four of them are located in the vicinity of the position, two times of the focal length. The maximum measurement range of about 20 mm is obtained using a focal length of 10 mm. In the y‐ and z‐axes displacement measurements, the linear range increases as the diameter of concave mirror increases. The longest linear range of 8 mm is achieved at mirror radius of 10 mm.

Originality/value

This is the first demonstration of three axes directional displacement measurements using a concave mirror as a target

Details

Sensor Review, vol. 31 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 29 March 2011

S.W. Harun, H.Z. Yang and H. Ahmad

The purpose of this paper is to investigate, theoretically and experimentally the performance of liquid refractive index sensor (LRIS).

Abstract

Purpose

The purpose of this paper is to investigate, theoretically and experimentally the performance of liquid refractive index sensor (LRIS).

Design/methodology/approach

The proposed LRIS is based on the intensity modulation and a bundle fiber. The mathematical model is used to study the effect of inclination angle on performance of the sensor.

Findings

The theoretical result shows that the highest sensitivity can be achieved by using a probe inclined with angle 20° which is almost 13 times higher than that of 0° inclination. In the experiment, three different liquids: isopropyl alcohol, water and methanol are used to investigate the sensor response. Both theoretical and experimental results show that the peak power and the location of the displacement curve changes with refractive index. The sensitivities are obtained at 0.11/mm and 0.04/mm for the sensors with 10° and 0° inclination angles, respectively.

Originality/value

In this paper, a simple LRIS is proposed using a bundle fiber as a probe at various inclination angles.

Details

Sensor Review, vol. 31 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 22 June 2012

M. Yasin, H.A. Rahman, N. Bidin, S.W. Harun and H. Ahmad

The purpose of this paper is to demonstrate a simple design of a fiber optic displacement sensor using a multimode plastic fiber coupler based on reflective intensity…

Abstract

Purpose

The purpose of this paper is to demonstrate a simple design of a fiber optic displacement sensor using a multimode plastic fiber coupler based on reflective intensity modulation technique.

Design/methodology/approach

The performances of this sensor are investigated by correlating the detector output with different light sources, coupling ratios and various real objects with different reflectivity properties namely aluminum, brass and copper. In contrast to the output profile produced by probes with multiple fibers placed adjacently together, this sensor uses only one fiber for sending and receiving the light and therefore only the back slope exists.

Findings

Aluminum exhibit the highest performance among the real objects when coupled with a red He‐Ne laser and a coupling ratio of 50:50 with a sensitivity, linear range, resolution and dynamic range of 1.7 mV/mm, 1.5 mm, 16 μm, and 5.0 mm, respectively.

Originality/value

This is the first demonstration of a fiber optic displacement sensor using fiber coupler probe with successful examination of the correlation between the detector output, variation in coupling ratios and reflectivity properties of the tested real objects.

Details

Sensor Review, vol. 32 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 22 June 2012

H. Ahmad, M. Yasin, K. Thambiratnam and S.W. Harun

The purpose of this paper is to propose and demonstrate a simple yet accurate optical fibre based sensor capable of performing micron and sub‐micron thickness measurement.

Abstract

Purpose

The purpose of this paper is to propose and demonstrate a simple yet accurate optical fibre based sensor capable of performing micron and sub‐micron thickness measurement.

Design/methodology/approach

The proposed sensor consists of a multimode plastic probe, three He‐Ne lasers and translation stages along with a silicon photodiode and a lock‐in amplifier to measure the output voltage as the displacement of the sensor is increased.

Findings

The system operating with a source wavelength of 633 nm can provide measurements of up to 3 μm with a sensitivity of 0.0054 mV/μm.

Originality/value

The thickness of the sample can be obtained from a linear equation correlating the thickness of the sample to the displacement of the sensor at which the peak output voltage is obtained, or by correlating the thickness of the sample directly to the peak output voltage measured.

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Article
Publication date: 14 January 2014

Malathy Batumalay, F. Ahmad, Asiah Lokman, A.A. Jasim, Sulaiman Wadi Harun and H. Ahmad

A simple tapered plastic optical fiber (POF) sensor is proposed and demonstrated for measurement of uric acid concentrations in de-ionized water. The paper aims to discuss…

Abstract

Purpose

A simple tapered plastic optical fiber (POF) sensor is proposed and demonstrated for measurement of uric acid concentrations in de-ionized water. The paper aims to discuss these issues.

Design/methodology/approach

The sensor operates based on intensity modulation technique as the tapered POF probe which was coated by a single walled carbon nonotubes polyethylene oxide (SWCNT-PEO) composite is immersed into the uric acid solution. The probe was fabricated using an etching method and has a waist diameter of 0.46 mm and tapering length of 10 mm.

Findings

As the concentration varies from 0 to 500 ppm, the output voltage of the sensor increases linearly from 6.13 to 7.35 mV with a sensitivity of 0.0023 mV/% and a linearity of more than 97.20 percent. The SWCNT-PEO composite coating increases the sensitivity of the proposed sensor due to the effective cladding refractive index, which increases with the coating and thus allows more light to be transmitted from the tapered fiber.

Originality/value

This is the first demonstration of the tapered POF sensor for measurement of uric acid concentrations in de-ionized water.

Details

Sensor Review, vol. 34 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 26 July 2021

Rajae Jemghili, Abdelmajid Ait Taleb and Mansouri Khalifa

Although many researchers have widely studied additive manufacturing (AM) as one of the most important industrial revolutions, few have presented a bibliometric analysis…

Abstract

Purpose

Although many researchers have widely studied additive manufacturing (AM) as one of the most important industrial revolutions, few have presented a bibliometric analysis of the published studies in this area. This paper aims to evaluate AM research trends based on 4607 publications most cited from year 2010 to 2020.

Design/methodology/approach

The research methodology is bibliometric indicators and network analysis, including analysis based on keywords, citation analysis, productive journal, related published papers and authors indicators. Two free available software were employed VOSviewer and Bibexcel.

Findings

Keywords analysis results indicate that among the AM processes, Selective Laser Melting and Fused Deposition Modeling techniques, are the two processes ranked on top of the techniques employed and studied with 35.76% and 20.09% respectively. The citation analysis by VOSviewer software, reveals that the medical applications field and the fabrication of metal parts are the areas that interest researchers greatly. Different new research niches, as pharmaceutical industry, digital construction and food fabrication are growing topics in AM scientific works. This study reveals that journals “Materials & design”, “Advanced materials”, “Acs applied materials & interfaces”, “Additive manufacturing”, “Advanced functional materials” and “Biofabrication” are the most productive and influential in AM scientific research.

Originality/value

The results and conclusions of this work can be used as indicators of trends in AM research and/or as prospects for future studies in this area.

Details

Rapid Prototyping Journal, vol. 27 no. 7
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 27 November 2018

Sarbjit Kaur, Niraj Bala and Charu Khosla

The biomaterials are natural or synthetic materials used to improve quality of life either by replacing tissue/organ or assisting their function in medical field. The…

Abstract

Purpose

The biomaterials are natural or synthetic materials used to improve quality of life either by replacing tissue/organ or assisting their function in medical field. The purpose of the study is to analyze the hydroxyapatite (HAP), HAP-TiO2 (25 percent) composite coatings deposited on 316 LSS by High Velocity Flame Spray (HVFS) technique.

Design/methodology/approach

The coatings exhibit almost uniform and dense microstructure with porosity (HAP = 0.153 and HAP-TiO2 composite = 0.138). Electrochemical corrosion testing was done on the uncoated and coated specimens in Ringer solution (SBF). As-sprayed coatings were characterized by XRD, SEM/EDS and cross-sectional X-ray mapping techniques before and after dipping in Ringer solution. Microhardness of composite coating (568.8 MPa) was found to be higher than HAP coating (353 MPa).

Findings

During investigations, it was observed that the corrosion resistance of steel was found to have increased after the deposition of HAP and HAP-TiO2 composite coatings. Thus, coatings serve as an effective diffusion barrier to prohibit the diffusion of ions from the SBF into the substrate. Composite coatings have been found to be more corrosion resistant as compared to HAP coating in the simulated body fluid.

Research limitations/implications

It has been concluded that corrosion resistance of HAP as well as composite coating is because of the desirable microstructural changes such as low porosity high microhardness and flat splat structures in coatings as compared to bare specimen.

Practical implications

This study is useful in the selection of biomedical implants.

Social implications

This study is useful in the field of biomaterials.

Originality/value

No reported literature on corrosion behavior of HAP+ 25%- TiO2 has been noted till now using flame spray technique. The main focus of the study is to investigate the HAP as well as composite coatings for biomedical applications.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 14 January 2014

Gary Hunter

Abstract

Details

Sensor Review, vol. 34 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 25 July 2018

Mohd Rafee Baharudin, Hairul Nazmin Nasruddin, Anita Abdul Rahman, Mohd Razif Mahadi and Samsul Bahari Mohd Noor

The purpose of this paper is to design a numerical model to calculate the individual evacuation time among secondary students based on Knowledge, Attitude and Practice…

Abstract

Purpose

The purpose of this paper is to design a numerical model to calculate the individual evacuation time among secondary students based on Knowledge, Attitude and Practice (KAP), human characteristics and travel distances.

Design/methodology/approach

Validated KAP questionnaires were distributed among 290 respondents. The KAP level was obtained based on the assigned scores. During a fire drill, the individual evacuation time was calculated by using personal digital watch while the travel distances were recorded and measured. A linear numerical model was derived by using multiple linear regression to identify the significant variables and the coefficients.

Findings

The CVI, CVR and Cronbach’s α value (0.75, 0.59 and 0.7, respectively) which are greater than minimum accepted level proved the reliability and consistency of the instrument. The evacuation time prediction by the developed numerical model showed strong correlation with the actual time (R=0.95). The regression analysis found that 89 per cent proportion of variance in the evacuation time are determined by the predictors. Based on the linear equation, it found that the decrease in weight, knowledge level and walking speed while increase in BMI, flat and stair travel distances could increase evacuation time. From the six significant variables, weight, walking speed, flat and stair distances showed significant correlation in the model with p<0.001, while BMI and knowledge showed p<0.05. The integration with mobility factors expand the formula which applicable within dynamic fire scenario.

Research limitations/implications

The involvement of examination students in the study is restricted by the Ministry of Education Malaysia to avoid interruption of learning session which limited the data representation.

Originality/value

Instead of using the traditional direct measurement of the evacuation time, the developed numerical model is an alternative convenient approach which could be used as one of the pre-assessment tool to identify the level of safety among students. The low cost and shorter time application of this model become one of the greatest advantages compared to other available approaches. The calculated individual evacuation time could be used directly to develop a better fire safety policy.

Details

International Journal of Building Pathology and Adaptation, vol. 36 no. 5
Type: Research Article
ISSN: 2398-4708

Keywords

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