Variants of individual filter samplers and various ways of controlling the speed of the air passing through the filter under different conditions of samplers’ application are considered. Prerequisites for improving reliability of the results obtained, as well as conditions of the samplers’ optimization and application have been analyzed. Pros and cons of their speed control were pointed out. Emphasis is made as to the importance and adequacy of the respiratory signals or their imitation as a means of controlling the true speed of the air passing through the sampler filter.

Optical properties of quasi one-dimensional binary thin films made of interchanging Ag and Ni layers are investigated in this work. For this purpose we applied the so called matrix method implementing Maxwell equations for electromagnetic waves propagation thru 11 layers of Silver and Nickel thin layers (20nm and 30nm respectively) separated by one Ni layer with variable thickness. Study showed that by changing only one middle layer dimensions it is possible to tune optical properties in wide range, both by the means of transmission intensity band minimum location and depth. This approach will result in simplification of manufacturing process.

Technological control of nitration of organic compounds needs data about a composition of acid nitrating mixture before and after nitration. Content of water is a crucial factor for efficiency and safety of the nitration process. The industrial laboratories demands for fast, accurate, precise, low cost and easy to maintain analytical methods. This paper presents the development of a protocol for determination of composition of acid nitrating mixture. The determination of nitric acid is based on redox back titration. Determination of sulfuric acid is based on direct precipitation titration. Water content is determined by calculation. The proposed method showed good accuracy, precision and selectivity, with recoveries (99.80±0.06)% H2SO4 and (98.91±0,80)% HNO3,and total analysis time 20 min.

The work reported herein is about a study to establish the best combination of injection moulding parameters in minimising warpage over a front panel housing using a simulation software. The warpage in x and y directions were analysed using Autodesk Moldflow Insight (AMI) software where specifications of injection moulding machine (Nessei NEX 1000) and P20 as a mould material were set in this analysis. On top of that, Acrylonitrile Butadiene Styrene (ABS) was adopted as the plastic material. Four process parameters were taken as variable factors which are mould temperature, melt temperature, packing pressure and packing time. Design Expert 7.0 software was used to optimise warpage obtained from AMI analysis. The mathematical model was obtained from Design of Experiment (DOE) integrated with Response Surface Methodology (RSM) along with Center Composite Design (CCD) method. Results showed that packing pressure and melt temperature is the most significant factor leading to warpage whilst mould temperature and packing time demonstrated the least significant in both directions.

This study focuses on the optimisation of the injection moulding parameters to minimise the shrinkage and warpage on moulded parts using Autodesk Moldflow Insight (AMI) 2012 software. The shrinkage and warpage of the parts were analysed in x and y axis. Mould temperature, melt temperature, packing pressure and packing time were selected as variable process parameters. Design Expert software was used as a means to analyse and optimise the selected parameter setting in order to reduce shrinkage and warpage on front panel housing. A polynomial model using Design of Experiment (DOE) was integrated with Response Surface Method (RSM) using Centre Composite Design (CCD) method and an anticipative RSM was interfaced with an effective Genetic Algorithm (GA) to find the optimum value of process parameters. The shrinkage and warpage of the moulded parts has been reduced down to 56 % and 68 % respectively after the optimisation

In this study, the polycaprolactone diol (PCL), 4,4’-diphenylmethane diisocyanate (MDI) and 2,6-Pyridimthanol (2,6-PDM) were reacted in the N,N-dimethyl acetamid (DMAc) solvent to form the polyurethane (PU). Finally, the silver nitrate was added into the polyurethane. The silver ion was reacted with 2,6-Pyridimthanol to form the metal coordinate bond in PU/AgNO3. Various addition ratios of silver nitrate were studied to understand the influence on the properties of polyurethane containing the pyridine ring. The characteristic peak was identified to determine the structure of polyurethane. The residue of thermal decomposition could be used to determine the addition of silver nitrate, and the variation of degradation temperature could be observed. When the content of silver nitrate was increased, the glass transition temperature (Tg) would be increased significantly. The stress-strain test showed that when the content of silver nitrate was increased, the elongation at break of PU/AgNO3 would be reduced significantly. The NaOH aqueous solution was used to decompose PU/AgNO3, and the degradation rate of PU/AgNO3 was observed in a short time. The scanning electron microscope (SEM) was used to observe the pore and crack of PU/AgNO3 after hydrolytic reaction