Fat and protein contents, acidity and somatic cell counts in bulk milk of Holstein cows in the Khorasan Razavi Province, Iran

Relationships between total bulk milk somatic cell score (SCS) and milk fat and protein contents and acidity were investigated in the Khorasan Razavi Province, a region that contributes 6.83% of total milk production in Iran. A total of 1476 samples were analysed. Data were obtained by randomly collecting 123 samples of bulk tank milk from 41 dairy farms during April 2006 to March 2007, every month. Milk was analysed for titratable acidity, protein and fat contents and somatic cell counts (direct microscopic cell count and with Somatos, Russia). Microscopic and Somatos somatic cell counts were comparable. Results showed that the season of raw milk production did not have a significant effect on acidity. Milk fat content increased gradually from spring to winter and there were significant differences ( P <  0.05) between spring and other seasons. Higher levels of milk protein fractions were observed during the autumn and winter than in other seasons. The highest total bulk milk somatic cell counts were observed in July. Total bulk milk SCS had significant effects ( P <  0.05) on acidity and fat and protein contents. Moreover, the level of acidity and fat in milk decreased with increasing SCS. A significant positive relationship was observed between total bulk milk SCS and the protein content of milk. Elevated SCS were associated with lowered milk quality in Holsteins in the Khorasan Razavi Province.     

The effect of Lallemantia royleana (Balangu) seed, palmate-tuber salep and carboxymethylcellulose gums on the physicochemical and sensory properties of typical soft ice cream

This study was aimed primarily at determining the suitability of two Iranian sources of hydrocolloid, Balangu seed and palmate-tuber salep (PTS), for the production of ice cream mix. For this purpose, the effect of these gums and carboxymethylcellulose (CMC) on some physicochemical and sensory characteristics of a typical soft ice cream was investigated. In comparison with carboxymethylcellulose, Balangu seed did not make a significant difference ( P  > 0.05) to most characteristics and could be used as a suitable stabiliser. Although products prepared using only the palmate-tuber salep showed more differences from the corresponding ones with carboxymethylcellulose, the variations were not significant.     

ANTIMICROBIAL PROPERTIES OF NISIN-COATED POLYMERIC FILMS AS INFLUENCED BY FILM TYPE AND COATING CONDITIONS

Polymeric films were coated with nisin, an antimicrobial peptide, for potential application in shelf-life extension of food. Five commercial packaging films with varying surface energies were compared. The highest antimicrobial activity was observed on the most hydrophobic nisin-coated films (surface energy ± 32 dyne/cm). The binding affinity of nisin to the surface of ethylene acrylic acid copolymer (surface energy = 32 dyne/cm) was investigated. Films were coated in nisin solutions under varying conditions including nisin concentration, contact time, solution's volume to film area ratio, pH of coating solution and temperature during coating. Stronger nisin activity was detected on films as the coating time increased from 30 s to 2 h. Higher nisin coating concentration also promoted the binding of nisin to films with saturation level observed at 250 μg/mL. Films coated with nisin using a higher solution to film area ratio (0.84 compared to 0.14 and 0.28 mL/cm²) also exhibited higher nisin activity.     

Nonlinear control techniques for an atomic force

Two nonlinear control techniques are proposed for an atomic force microscope system. Initially ,a learning- based control algorithm is developed for the microcantilever-sample system that achieves asymptotic cantilever tip tracking for periodic trajectories. Specifically ,the control approach utilizes a learning- based feedforward term to compensate for periodic dynamics and high- gain terms to account for non-periodic dynamics. An adaptive control algorithm is then developed to achieve asymptotic cantilever tip tracking for bounded tip trajectories despite uncertainty throughout the system parameters. Simulation results are provided to illustrate the efficacy and performance of the control strategies.     

叠后地震数据的自相似分段和多重分形

地质分层是石油工程中的一项重要的基础工作.叠后地震数据和测井数据的时间序列能反映地下分层.由于地层的非均质性和不同成因特性,它们表现出具有复杂模式的多重分形特性.在多重分形结构中,序列中的任何部分都具有不同的赫斯特(Hurst)指数,可反映其性质,并可用于分区检测.时间序列是井眼附近的叠后地震道和测井数据.自相似自回归...     

A Novel Approach for Energy and Water Conservation by Using Silver-Carbon Quantum Dots Hybrid Nanofluids in Wet Cooling Towers Systems

This study presents the use of Silver-Carbon Quantum Dots (Ag-CQD) hybrid nanofluids,prepared by a facile wet chemical method,for heat transfer enhancement of w...