My Talks

Internal Singapore Synchrotron Light Source seminar series, season 4. Exploring Human Teeth Growth Patterns through Micro X-ray Fluorescence Mapping

Internal Singapore Synchrotron Light Source seminar series, season 3. Classification of the Residues after High and Low Order Explosions using Machine Learning Techniques on Fourier Transform Infrared (FTIR) spectra

In Session: Open Science and dissemination of knowledge

Brief introduction of using infrared spectroscopy for fuel fraud detection. Presentation of available sampling techniques for liquid samples (flow cells, ATR mode). Pointing the key issues in the experiment design and data processing for the reproducible research.

Internal Singapore Synchrotron Light Source seminar series, season 2. Presentation of the scientific method for contemporary experiment design.

Talk at ICAVS conference presenting application of 2D correlation spectroscopy method for the results obtained during propolis drying experiment

Internal Singapore Synchrotron Light Source seminar, season 1. Presenting the fundamentals of 2D correlation spectroscopy for time trials of liquid samples measured in open environment (air drying)

Counterfeit and Substandard Pesticides: The potential harm emanating from the ingestion of pesticide residues is a serious public health threat. Illicit pesticides trafficking is carried out by organized criminal networks, which exploit international shipping routes to disseminate five product categories,i.e. expired, counterfeit, mislabeled and unauthorized pesticides imports, and refilled product containers. Fuel Fraud: In importing countries, fuel fraud is driven by disparities in tax rates applied in domestic jurisdictions. It may take the form of purchasing fuel in a State with relatively low tariffs and VATs and selling it in a neighboring country with higher rates or misrepresenting a type of fuel taxed at a lower rate as a fuel taxed at a higher rate. It also gives rise to ‘cocktailing’, or chemically altering fuels so that they mimic hydrocarbons products assessed for lower tariffs or VATs, and then selling them as higher-taxed fuels.

Carbon nanotube reinforced composite materials are promising materials for the multiple potential applications in high-tech industry. Gaining the insight into the chemical composition of such materials at nanometer spatial resolution may provide a way for the improvement of manufacturing process. By combining infra-red spectroscopy (IR) and atomic force microscopy (AFM) it is possible to perform the chemical mapping with the spatial resolution down to 30 nm. The CNT nanocomposites were investigated by means of nanoIR2 and nanoIR3 systems. Infrared signal intensity measured in this method is influenced by the topography features of the investigated sample. Discussion of the correlations between the parameters recorded during the experiments will be presented in this contribution. Special attention will be given to data-processing work-flow with the help of open source software suites: R environment, ImageJ and Gwydion in order to ensure interpretability and reproducibility of the collected data. Particularly the problem of obtaining topography-free infrared absorbance signal is discussed and some possible solutions will be suggested.

Edible birds’ nest (EBN) is a traditional Chinese cuisine and medicine made by cavedwelling birds called swiftlets; Aerodramus, Hydrochous, Schoutedenapus and Collocalia. It is a culinary delicacy, which can retail at over 4000 USD per kilogram. EBN has been scientifically proven to have nutritional properties; improvement in bone strength cell division, anti-aging and antiviral, to name a few. While EBN has been demonstrated to have many health benefits, recent studies have highlighted its health risks. High nitrite content was found in EBN collected inside caves. This increases the risk of cancer due to the increased production of carcinogenic nitrosamines. In 2013, to combat this, China imposed a trade ban on EBN with some South East Asian countries like Malaysia until healthier harvesting practices were adopted. Only a few Malaysian producers were able to meet requirement. The low supply drove up the prices of EBN. Some producers, in order to meet demand, allegedly used adulteration techniques to add impurities to increase the weight. Adulterated or fake EBN may be hazardous to the consumers. A total of 8 samples pieces of original EBN sourced from 5 different provinces in Vietnam, together with various materials such as tremella fungus, pork skin, karaya gum, fish swimming bladder, jelly, agar, monosodium glutamate and egg white used to adulterate EBN have been analyzed. The main goal of our work was to establish a reliable and robust model for fast identification and detection of counterfeited EBN products by using FTIR microspectroscopy in conjunction with R Platform for statistical computing. This model can be distributed later among Health Regulatory Authorities (HSA) and food industry laboratories.

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abstract

Nanostructural composites reinforced with carbon nanotube assemblies, such as CNT fibres and mats are interesting materials for the multiple potential applications: from avionics to high-tech industry. Possibility to gain insight into the chemical composition of such materials may provide a way for their further development and improvement of manufacturing process. By combining infra-red spectroscopy (IR) and atomic force microscopy (AFM) it is possible to perform the chemical mapping with the spatial resolution down to 30 nm. The CNT nanocomposites were analysed by means of nanoIR2 system (Anasys Instruments, USA). Due to technique specific method of the detection of the infrared signal special attention must be paid during data-processing stage. Obtained results were evaluated with the help of R - open source environment for statistical analysis in order to ensure interpretability and reproducibility of the collected data. Various modes of measurements were processed, visualised and correlated to gain a better understanding of the system under investigation. Particularly the problem of obtaining topography-free infrared absorbance signal is discussed and some possible solutions are suggested in this contribution.

Analysis of hyperspectral data sets very often requires application of repetitive procedures. Proposed solution based on the R open source Environment has a number of advantages including cost-effectiveness, transferability and scalability. Code-driven analysis complies with the reproducible research requirements. R platform can be used for the analysis of infrared spectra of various types of food samples allowing for dimension reduction, clustering and finally identification and visualization.

The main goal of this project is to establish a reliable and robust model for fast identification and detection of counterfeited food products by using FTIR spectroscopy in conjunction with R Platform for statistical computing. FTIR preliminary analysis will be performed on samples which adulterations are quite often in recent years due to the high economic value and limited supply. Collecting the spectral data is important but only first step in the analysis of samples. Next, crucial for achieving the goal of the project, is data evaluation stage. Proposed in this contribution work-flow is employing open source R Environment for pre-processing and statistical analysis of the spectral data. In order to enable user-friendly interface Shiny package will be used. In this way power and flexibility of R is hidden for the end-user. Scalability of this solution - even by implementing Big Data algorithms gives high degree of freedom while Open Source license will help to disseminate the work-flow procedures to developing countries without extra costs, and additionally can be used to interpret straightforwardly analyzed samples even by non-specialized person.

poster

Modern technique combining infra-red spectroscopy and atomic force microscopy (AFM) allows the chemical mapping with the spatial resolution down to 30 nm. However, due to specific detection of the infrared signal special attention must be paid to data-processing stage. In this contribution evaluation of the nanoscale chemical mapping results of carbon nanotube composite materials will be presented. Nanostructural composites reinforced with carbon nanotube assemblies, such as CNT fibres or mats are promising materials for the numerous applications from avionics to high-tech industry. Ability to gain insight into the chemical composition of such composite materials may provide a way for their further improvement.

Gleason grade is the most popular system used to classify different stages of prostate cancer. However, this method is highly dependent on experience of the histopathologists as the assessment is based only on microscopic appearance of analysed tissue sections. Complimentary system is needed that integrates tissue architecture and its biochemistry. SRIXE (Synchrotron Radiation Induced X-ray Emission) is powerful, yet not destructive technique used to determine the elemental make-up of a sample. As very often valuable information is hidden in a huge number of variables, that is why dedicated multivariate statistical method has to be applied for straightforward analysis. Comprehensive comparison of classification models based on elemental concentrations in prostate tissue is presented in this poster.