T. Lalinsky´, Sˇ. Haščík, Ž. Mozolová, E. Burian, M. Krnáč, M. Tomáška, J. Škriniarová, M. Drzˇík, I. Kosticˇ and L. Matay
A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure based…
Abstract
A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure based microelectromechanical systems (MEMS) devices. Based on the micromachining technology, two different MEMS devices were designed and analyzed. The first one was micromechanical thermal converter (MTC) and the second one was a micromechanical coplanar waveguide (MCPW). The basic electro‐thermal as well as microwave properties of the MEMS devices designed are investigated. The results obtained are also supported by simulation. The advantages of the fixed micromechanical structures in the field of design of new MEMS devices are discussed.
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Mir-Hassan Moosavy and Nassim Roostaee
The composition and properties of milk are considerably important for dairy farmers, manufacturers and consumers. Despite the significant role of bovine milk in Iranian dairy…
Abstract
Purpose
The composition and properties of milk are considerably important for dairy farmers, manufacturers and consumers. Despite the significant role of bovine milk in Iranian dairy products, there is little information about the effect of production season and location on the physicochemical properties of pasteurized milk as a final product. The purpose of this study was to investigate the effects of seasonal, geographical and product brand variations on the chemical components and physical properties of Iranian pasteurized bovine milk.
Design/methodology/approach
A total of 400 samples of pasteurized milk were obtained during a 12-month period, from April 2014 to March 2015, using random sampling. Chemical components (protein, fat, lactose, dry matter and solids-not-fat) and physical properties (freezing point, extraneous water content, titratable acidity, density and pH) of the collected samples were analyzed. A one-way ANOVA was used to perform the statistical analysis of data, and results were presented as the mean ± standard deviation.
Findings
It was found that the biochemical constituents and physical properties of pasteurized milk samples were linked to seasonal and geographical variation parameters. The milk sampled during spring and summer contained significantly less fat, protein and solids-not-fat (p < 0.05) than samples in autumn and winter. Also, samples in spring had a significantly higher (p < 0.05) extraneous water (0.8 per cent) compared to milk sampled in winter (−0.4 per cent). Samples in Maragheh and Mianeh contained the highest level of fat (2.82 per cent) and protein (3.09 per cent) content in the province. The sampled milk from the south (Mianeh and Hashtrud) and the northwest (Marand) had also significantly higher (p < 0.01) freezing points than the other areas. No significant differences (p > 0.01) were found in physicochemical properties in different product brands of the milk samples.
Originality/value
Seasonal and geographical parameters are crucial factors in the diversity of physicochemical parameters of commercial pasteurized milk. In this study, unlike the other studies, differences in milk product brand were not significant. Further research will be needed to assess other factors such as the effect of management practices and feeding strategies on farms.