Ahmed Al-Shamma’a

Flexible microwave sensors for real-time analysis of water contaminants

This paper reports on the development of novel microwave sensors for water contaminant analysis in real time. In particular, changes in the microwave part of the electromagnetic spectrum are used as an indicator of water quality. The sensing element was designed on a flexible substrate in order that it is less prone to failure due to mechanical damage, thus providing longevity. This also allows for a broad range of applications where a sensor, or sensors, could be placed in water reservoirs or water pipes. The sensing element consists of silver metal patterns which form interdigitated electrodes (IDE) in various configurations on polyimide flexible laminate substrates. The effect of IDE sensor configuration on the sensitivity of reflected signals represented by S11 parameters was studied. The developed system confirmed the viability of using microwaves for real-time water quality monitoring as the corresponding spectra for air, deionised water and tap water were unique with clearly observed shifts in the resonant frequencies of the sensors when placed in direct contact with various water samples.

Microwave spectroscopy: a potential technique to analyse bitumen dielectric and physical properties

Bitumen is a complex mixture of high molecular weight organic compounds, predominantly hydrocarbons, with carbon numbers greater than C24. It has high carbon to hydrogen ratios, and also contains small amount of metals such as nickel, iron and vanadium. The application of bitumen in the pavement industry is mainly as a binding agent for road construction/surfacing. Hence, this paper discusses the use of microwave spectroscopy (MS) as a potential technique to analyse bitumens dielectric properties to indicate change in some of its physical properties after its interaction with both treated and untreated coarse rubber in the field of pavement engineering. A comparison of the existing techniques for the quantitative and qualitative analysis of bitumen is given. The drawbacks of the existing techniques are also discussed and the paper addresses how the MS technique can overcome these drawbacks. The MS technique is investigated by analysing different bitumen samples including pure bitumen and samples taken from rubber–bitumen blends. Each of the blends used rubber with different surface properties which have different effects on the properties of the resulting bitumen. The paper highlights the novelty and advantages for the MS technique in reducing analysis time, solvent usage and potential take-up by the industry.

Microwave Spectroscopy for the Analysis of Absorption Properties of Treated Waste Rubber Aggregates

AbstractThis paper discusses for the first time the use of noninvasive and nondestructive microwave spectroscopy to analyze the effect of chemical treatment on the absorption properties of waste rubber aggregate material when it is reacted and heated with bitumen. Oxidation and cross-linking was used to treat the waste rubber aggregates. The surface properties of oxidized rubber were analyzed using scanning electron microscopy. The bitumen samples obtained from treated and untreated rubber-bitumen blends were analyzed using microwave spectroscopy. This technique was to measure instantaneously the reduction in absorption properties of rubber when it is reacted with bitumen after treatment, compared with the bitumen samples obtained from untreated rubber-bitumen blends before treatment. The results of the scanning electron microscopy analysis show that the surface properties of waste rubber have been changed, developing surface roughness after the oxidation process. This was consistent with the microwave sp...

Experimental investigations of microwave plasma UV lamp for food applications.

The food industry is keen to have new techniques that improve the safety and/or shelf life of food products without the use of preservatives. There is considerable interest in developing UVlight and ozone (O3) treatments to enhance shelf life. A microwave radiation device that is a novel source of germicidal UV and O3 suitable for the food industry has been developed, which offers speed, cost and energy benefits over existing sources. With this system comes the need to monitor a number of conditions, primarily UV intensity and ozone gas concentrations. The effectiveness of intense UV exposure for short periods of time was assessed on different microorganisms. Culture plates were exposed to a range of doses of UV-C light, and the reduction in numbers of surviving microorganisms was recorded. The results on the biocidal capacity of the microwave generated UV light are presented.

Milk Quality Monitoring Using Electromagnetic Wave Sensors

This chapter presents a novel approach to monitor the quality of milk products, based on electromagnetic wave spectroscopy. A comparative analysis is made to demonstrate the effectiveness of using microwave sensors over the other types, existing in the wide field of sensing technology. Three broadly used commercial varieties of milk, namely skimmed, semi-skimmed, and whole milk types are considered for the test measurements. The overall quality parameters of these products obtained from the market are comparatively measured in terms of their composition and spoilage with reference to ageing. The experiments carried out have illustrated that the sensor was able to distinguish one milk type from another. Moreover, it was also able to differentiate between fresh and aged milk samples of a given milk type as the number of days passes. The methodology used here employs Vector Network Analyser to capture spectral signatures in the form of scattering parameters from electromagnetic wave sensors. These data are then analysed to evaluate quality monitoring process achieved by these sensors. This work offers a potential platform for an economical, less complicated, and real-time milk quality control mechanism that can be employed outside of the laboratories at medium or large scale retailers in milk supply chain hierarchy.

Real-Time Microwave, Dielectric, and Optical Sensing of Lincomycin and Tylosin Antibiotics in Water: Sensor Fusion for Environmental Safety

Antibiotics are widely used to prevent and treat bacterial infections in livestock animals, aquaculture, and humans. However, the unconditional use of those drugs as a growth promoter for livestock animals and the wrong usage as a treatment for infections in humans has led to high antibiotics pollution, especially in water resources. The elevated presence of antibiotics in water has resulted in the phenomenon known as the bacterial antibiotics resistance. To prevent ecological catastrophe, continuous real-time monitoring of water sources is necessary. The aim of this research work is to compare the abilities of three different techniques: novel electromagnetic wave spectroscopy, UV-Vis spectrophotometry, and capacitance sensing system for the real-time detection and quantification of antibiotics in water. Tylosin and lincomycin antibiotics were selected to the study, as both are regularly found in water sources. Two novel microwave sensor configurations were used: a planar sensor with interdigitated electrode pattern and a hairpin resonator sensor, as a means of real-time water analysis. Reflected S11 power signals were analyzed in GHz frequency range for microwave sensors. In parallel, UV-Vis spectrophotometry was used, where change in the optical absorbance was used as an indicator of water pollution, whereas change in the value of a capacitance in low frequency range has signalled the change in the dielectric properties of the solution. It was found that in all cases the changes in the measured parameters were dependent on both the type of antibiotic present in water and on its concentration. Fusion of all these techniques into a comprehensive sensing platform provides adequate real-time assessment of the water pollution with antibiotics and would allow adequate management of environment for safety and sustainable development. In particular, the lowest lincomycin samples’ concentration, 0.25 μg/l, was measured with a hairpin resonator sensor, while the lowest tylosin samples’ concentration, 0.20 μg/l, was measured with an IDE sensor. Since concentration in groundwater were 0.36 μg/l of lincomycin and 1.5 μg/l of tylosin, it is demonstrating a high-sensing platform utility.

Design and implementation of a non-invasive real-time microwave sensor for assessing water hardness in heat exchangers

Abstract A non-invasive-monitoring of concentration and dielectric properties of calcium hardness in heat exchanger cooling water was conducted with a 2.5 GHz microwave cavity resonator designed and fabricated locally for the experiment. The principle of electric dipole moment theories were used to analyse the sample solution that occurs as a function of calcium ion content. Artificial difference of water hardness was prepared by mixing CaCl2 in deionised water. The sample was centrally positioned in the electric field of the TM010 mode of a resonant cylindrical cavity. COMSOL simulation package was used to compare and validate the experimental cavity resonator frequency. Transmission signal (S21) measurements via vector network analyser at different concentrations were observed a linear relationship in amplitude with different frequency changes. In addition, calcium absorption provides a first-order change in material polarisation (i.e. real permittivity), and second-order transitions associated dielectric losses (i.e. imaginary permittivity). These research findings introduce a novel technique of real-time monitoring of water hardness concentration by using non-invasive microwave sensor.

Investigation of audible carbon monoxide alarm ownership

Purpose – The purpose of this paper is to outline the level of audible carbon monoxide (CO) alarm ownership. In this particular paper the data collected by the fire and rescue services from West Midlands and Merseyside will be analysed, and discussed. Design/methodology/approach – Research was conducted in two stages. Using the indices of multiple deprivation identified whether households in the top and bottom four areas owned an audible alarm. In stage two data loggers were placed into homes to take readings every minute for a total period of three days to three weeks. Findings – There was a noticeable trend that deprived areas were less likely to own audible CO alarms than homes in non-deprived areas. All homes surveyed in stage two had CO levels >0 which further emphasises that anyone can be under health risk and that perhaps the maintenance of gas appliances and other sources is not being conducted at regular intervals. Social implications – This paper aims to raise awareness regarding not only the sy...