Characterisation and optical vapour sensing properties of PMMA thin films

The present article reports on the characterisation of spin coated thin films of poly (methyl methacrylate) (PMMA) for their use in organic vapour sensing application. Thin film properties of PMMA are studied by UV–visible spectroscopy, atomic force microscopy and surface plasmon resonance (SPR) technique. Results obtained show that homogeneous thin films with thickness in the range between 6 and 15 nm have been successfully prepared when films were spun at speeds between 1000?5000 rpm. Using SPR technique, the sensing properties of the spun films were studied on exposures to several halohydrocarbons including chloroform, dichloromethane and trichloroethylene. Data from measured kinetic response have been used to evaluate the sensitivity of the studied films to the various analyte molecules in terms of normalised response (%) per unit concentration (ppm). The highest PMMA film sensitivity of 0.067 normalised response per ppm was observed for chloroform vapour, for films spun at 1000 rpm. The high film's sensitivity to chloroform vapour was ascribed mainly to its solubility parameter and molar volume values. Effect of film thickness on the vapour sensing properties is also discussed.     

Respiratory effects in people exposed to arsenic via the drinking water and tobacco smoking in southern part of Pakistan

In this study, a survey has been conducted during 2005-2007 on surface and groundwater arsenic (As) contamination and its impact on the health of local population, of villages located on the banks of Manchar lake, southern part of Sindh, Pakistan. We have also assessed the relationship between arsenic exposure through respiratory disorders in male subjects with drinking water and smoking cigarettes made from tobacco grown in agricultural land irrigated with As contaminated lake water. The biological samples (blood and scalp hair) were collected from As exposed subjects (100% smokers) and age matched healthy male subjects (40.2% smoker and 59.8% non smokers) belong to unexposed areas for comparison purposes. The As concentration in drinking water (surface and underground water), agricultural soil, cigarette tobacco and biological samples were determined by electrothermal atomic absorption spectrometry. The range of As concentrations in lake water was 35.2-158 µg/L (average 97.5 µg/L), which is 3-15 folds higher than permissible limit of World Health Organization (WHO, 2004). While the As level in local cigarette tobacco was found to be 3-6 folds higher than branded cigarettes (0.37-0.79 µg/g). Arsenic exposed subjects (with and without RD) had significantly elevated levels of As in their biological samples as compared to referent male subject of unexposed area. These respiratory effects were more pronounced in individuals who had also As induced skin lesions. The linear regressions showed good correlations between As concentrations in water versus hair and blood samples of exposed subjects with and without respiratory problems.     

Towards stable diagnostic setups in clinical proteomics: Absolute quantitation of peptide biomarkers using MALDI‐TOF‐MS

In routine clinical diagnostics, peptide biomarkers are most commonly quantified using immunological techniques but these methods often lack sensitivity and/or specificity. Hence, quantitative mass spectrometry detection is desirable as an alternative diagnostic tool. To date, quantitative mass spectrometry is mostly based on ESI‐MS coupled to LC, requiring highly sophisticated instrumentation and knowledge and is time consuming and expensive. In contrast, MALDI‐TOF‐MS is a very simple, sensitive and rapid method for the detection of peptide biomarkers. However, the infeasibility of absolute quantification has been a tremendous handicap to the use of MS in stable clinical diagnostics. Here, we describe the development of a technical platform based on ClinProt particles and heavy‐isotope internal peptide standards for the fast and reliable preparation of samples. This combines the advantages of MALDI‐TOF as a read‐out system with absolute quantitation of peptide biomarkers. As a proof‐of‐concept, this platform was successfully employed for the absolute determination of the concentration of the highly abundant serum peptide des‐Ala‐Fibrinopeptide A in 45 serum samples from healthy donors. Such technology essentially contributes to the development of a stable MALDI‐TOF‐MS‐based clinical assay.     

Remote Laboratory Architecture for the Validation of Industrial Control Applications

The seven engineering degrees of the Higher Technical School of Design Engineering (ETSID), Technical University of Valencia, include in their formation programs, subjects, and laboratory projects to instruct students in the aspects of the design, development, and validation of applications for process control, automation, industrial informatics, and embedded systems. Moreover, the authors participate in European projects of education such as the International Network of Embedded System (INES) and the European Project Semester (EPS), where exchange students remotely perform the first phase of their projects at ETSID from their home universities. To significantly reduce the cost of installing a huge number of real prototypes in labs and to fulfill the distance requirements of the exchange students, a remote laboratory architecture, i.e., simPROCes, has been designed. simPROCes not only permits the teleoperation of simulators/real prototypes but also allows that complete control applications be remotely tested and validated. simPROCes is precisely specified to be independent of the model of computer, data acquisition card, programming language, and operating system, and is transparent to the programmer and easy to use. This system is useful both for the education and development of control application purposes. A water tank process shows the installation procedure of simPROCes to test and validate control applications. The experience of applying simPROCes in the electronic engineering degree and within the framework of INES and EPS has been successfully rated by student surveys.     

Performance of a proposed complete wetting surface counter flow channel type liquid desiccant air dehumidifier

An idea that improves the wettability over the surfaces of a cylindrical dehumidifier channel was proposed and experimentally proved. Fibrous sheets were attached to the inner surfaces of the channel. The capillary effect of fibers sustains the complete wetting of the heat and mass transfer surfaces. The air to be dehumidified and cooled flows upward in the annulus space between the two layers of fibrous sheets, which are saturated with the downward flowing desiccant solution. The permeability of the fibrous sheet was determined experimentally. It was 2.43 × 10^?10 m². The measured solution flow rate due to the capillary suction of the sheets was Γ_in,min = 1.12 kg/h m. The liquid desiccant tested was H₂O/CaCl₂ with salt concentration ratios ranging from 35 to 40%. The measured distribution of the solution flow rate along the circumference of the sheets at the outlet showed 5% deviation from the average flow rate. This is a good indication for the good wettability of walls inside the dehumidifier.Feeding the solution by this mechanism has many advantages over spray feeding. Beside sustaining complete surface wetting, it also prevents channel blockage with solution, which is a main factor in increasing the air pressure drop. About 95% of the air pressure drop is saved in this study by avoiding these problems. A simple theoretical model for the heat and mass transfer processes inside the dehumidifier was developed and experimentally validated. In general, there is good agreement between the predicted and measured data. The developed model was utilized to study the effect of the different parameters on the dehumidifier performance. For a 1 m height dehumidifier with an inlet specific humidity and air temperature of 0.0234 kg_v/kg_a, and 35 °C, respectively, the predicted outlet air specific humidity was 0.0102 kg_v/kg_k and the corresponding outlet air temperature was 27.4 °C. The inlet solution temperature and salt concentration were 25 °C and 40%, respectively.     

A Web-based integrated design system: its applications on conceptual design stage

This paper describes the development of a Web-based integrated system for collaborative product development evolving from marketing analysis to prototype generation. The proposed system encompasses a marketing information system (MIS), a human resources management (HRM) system, a supply-chain management (SCM) system, a communication media, an integrated product design studio, a user interface and databases. It enables project planners, marketing analysts, designers, suppliers, and manufacturing planners to work at the early stages to reduce any unnecessary wasted time, resources, and costs, thus increasing the total product quality, maximising the organisation resources used, and reducing the total product cost and product lead time to better face global competition. The tangible advantage of implementing this system is that it provides an integrated environment for total product development from concept to realisation. Therefore, an efficient product development process is generated. One case study is demonstrated and discussed to validate the proposed system.     

Experimental Investigation of the Grain Noise in Interferometric Detection of Ultrasonic Waves

Besides their other obvious advantages over conventional ultrasonic sensors, laser interferometers offer optical diffraction limited apertures that are far smaller than the acoustic wavelength in the specimen under inspection. This unique feature can be exploited for the purposes of super-resolution near-field acoustic microscopy, which detects the rapidly decaying evanescent vibrations produced by surface and near-surface scatterers such as small fatigue cracks, pores, anomalous grains, etc. However, higher resolution also means higher sensitivity to inherent microscopic material inhomoge-neities. In this paper, experimental results are presented for the incoherent material noise in 2024 aluminum and Ti-6Al-4V titanium alloys at two different nominal frequencies of 5 and 10 MHz. It is shown that the incoherent grain noise significantly increases as the illuminated spot size decreases. Above the acoustic wavelength, the observed phenomenon is mainly due to the increasing sensitivity of the receiver to propagating scattered waves generated in the interior of the specimen. Below the acoustic wavelength, the further increasing material noise is mainly due to evanescent vibrations caused by nearby scatterers.     

Synthesis of Smart Core-shell Nanocomposites with Enhanced Photocatalytic Efficacy

ABSTRACT

This current research represents practical synthetic protocol for novel core-shell nanocomposites (CSNCs) containing titania. TiO₂/poly(anthranilic acid, m-aminobenzoic acid, and o-phenylenediamine) (TiO₂/PANA-m-ABA-o-PDA) CSNCs were fabricated applying 2:2:1 molar ratio of the appropriate monomers and varied loads of TiO₂ via polycondensation. The fabrication of the TiO₂/PANA-m-ABA- o-PDA CSNCs was affirmed using various characterizations. The bond between TiO₂ and PANA-m-ABA-o-PDA was detected in the FTIR spectra. The CSNC’s features are having core-shell structures with sizes 12–27 nm. Under irradiation, the CSNCs exhibit intensive photocatalysis efficacy toward methylene blue degradation. Acceptable explanations of the photocatalytic efficiency consequences were substantiated. The zeta potential of a particle (ζ), the polydispersity index (PDI), and y-intercept were anticipated via dynamic light scattering (DLS) of the terpolymer colloidal system. The procedure manipulates a facile, new, beneficial as well as cheap synthetic technique to fabricate innovative CSNC as a new potential formulation.     

Steam reforming of simulated pre-reformed naphtha in a PdAu membrane reactor

Process intensification in a membrane reactor is an efficient and compact way to produce hydrogen. A methane-rich gas mixture that simulated the composition of pre-reformed naphtha (PRN; with a steam-to-carbon ratio of 2.7) was reformed at temperatures of 550 °C–625 °C and pressures up to 40 barg. The reactor contained commercial steam reforming catalyst and a 14.8 cm long, 2.6 μm thick Pd-1.8Au (wt. %) membrane on a porous alumina support. Methane conversions approaching 90% were obtained in the membrane reactor at a gas-hourly space velocity of 676 h^?1, compared to ≤30% conversion at the same conditions in conventional reactor mode (CM) without withdrawing hydrogen through the membrane. The results were compared to steam methane reforming (SMR) in the membrane reactor at similar conditions. The nitrogen leak through the membrane increased slowly during the testing, because of both pinhole formation and some leakage through the end seals.