Effect of heat treatments on the meltability of cheeses

The effect of heat treatments on the meltability of cheese was investigated. Cheddar cheeses of different composition and low-moisture, part-skim Mozzarella cheese were studied at 1, 3, 6, and 12 wk of aging. Cheese samples were heated to 60 degrees C and held for 0, 10, and 20 min before allowing the melted cheese to flow. Mean meltabilities, over all ages, of both Cheddar and Mozzarella cheeses decreased significantly as holding time increased. Meltability of young cheese was scarcely affected by the holding time, in sharp contrast to that of the old cheese where increasing the holding time greatly reduced meltability.     

Influence of mineral phase in mineralization of a biocomposite containing chitosan,demineralized bone matrix and bone ash—in vitro study

A resorbable composite which acts as a active barrier in guided bone regeneration was fabricated using chitosan, demineralized bone matrix and bone ash. Its potential to form bone like apatite in simulated body fluid was assessed in this study. The mechanical strength of these composites was correlated with bone ash ratios and composites with better tensile strength were studied for their acellular bioactivity by incubating in simulated body fluid for 21 days. Composites without bone ash did not show acellular bioactivity which was confirmed by thermogravimetric analysis. In case of biocomposites with bone ash, there was an increase in residual weight indicating the mineralization of the composite. The composite containing bone ash has shown the peaks related to phosphate vibrations in its Fourier-transform infrared spectrum. Scanning micrographs revealed formation of apatite like crystals on its surface. Ca/P ratio was found to be 1·7 which is nearer to that of natural bone. Thus, prepared composites can be used as resorbable biocomposite in maxillofacial and oral defects.     

A new bistable laser diode configuration for all optical switching

A new bistable laser diode configuration for all optical switching has been suggested and its equivalent circuit model is developed. For switching the device to the high state (set) a TE mode optical pulse is required, which is the oscillating mode of the laser, whereas a TM mode pulse is used to bring the output to a low state (reset). But the wavelength of the set and reset pulses are the same as that of the lasing wavelength of the device. The static and dynamic characteristics are studied by simulating the equivalent circuit model using the circuit simulation program PSPICE. It is found that as the carrier lifetime τ_a of the absorption section increases, the width of the optical pulse required for reset increases nonlinearly. The rise and fall times are found to be 0.15 and 0.16 ns, respectively, for a τ _a, of 3 ns     

Electrochemical impedance study of thermally sprayable polyethylene coatings

In the present work low density poly ethylene (LDPE) and maleic acid grafted LDPE (LDPE-g-MAc) were pigmented with red iron oxide at three different concentrations (i.e., 20, 30 and 40 wt%). The pigmented compositions were prepared in extruder and then cryogenically grounded to bring them in powder form. These compositions were applied on grit blasted mild steel specimen by flame spray technique. Corrosion resistance of red iron oxide based compositions was studied by electrochemical impedance spectroscopy (EIS). The grafted LDPE containing 30 wt% red iron oxide showed maximum resistance to corrosion compared to 20 and 40 wt% red iron oxide based compositions.     

Mechanical spectra and calorimetric evaluation of gelatin–xanthan gum systems with high levels of co-solutes in the glassy state

Mechanical properties of gelatin–xanthan gum (XG) mixtures with high levels of co-solutes were examined by dynamic mechanical analysis (DMA). The mechanical spectra of the samples were modeled according to the Williams–Landel–Ferry (WLF) equation/free-volume theory, which requires an entropic lightly cross-linked network. For the α dispersion, E′ and E′′ superposed with the horizontal shift factor a_T, which was temperature-dependent according to the WLF equation; no other secondary dispersion mechanism was detected. The addition of XG to gelatin networks with high levels of co-solutes changed the glass transition temperature (T_g) and kinetics of glass transition and glassy states. In the glassy state, the WLF equation was unable to follow progress in the mechanical properties, which were better described by the Andrade equation. The calorimetric measurements of the gelatin–XG systems were made using a modulated temperature differential scanning calorimetry (MTDSC) to improve the determination of T_g. The samples were exposed to two cooling and heating cycles to provide a controlled recent thermal history in the temperature range of 40 °C to −70 °C. The T_g values of the samples were determined from the second heating cycle in the reversing heat signal. The calorimetric T_g values increased with increasing glucose syrup:sucrose ratio due to increased crosslinking, whereas mechanical T_g decreased with increased XG content due to network formation.     

Rheological evaluation of gelatin–xanthan gum system with high levels of co-solutes in the rubber-to-glass transition region

Effects of moisture content, xanthan gum (XG) addition, and glucose syrup (GS):sucrose ratio on the gelation of gelatin-XG systems with high levels of co-solutes were investigated in the rubbery and the glass transition regions. Frequency sweep tests were performed between 0.1 and 100 rad and the storage (G′) and loss (G″) moduli of the system were measured in the temperature range of 60 to −15 °C. The onset of glass transition region increased with decreasing moisture content. The time–temperature superposition yielded master curves of G′ and G″ as a function of timescale of measurement. G″ and G″ were superimposed with the horizontal shift factor a_T, which was temperature dependent according to the Williams–Landel–Ferry (WLF) equation. Glass transition temperature (T_g) of the samples were determined by dynamic mechanical analysis (DMA) from the peak of tan δ. T_g decreased with XG addition. The energy of vitrification of samples with XG increased compared to samples containing only gelatin. Relaxation spectra of the samples were calculated from rheological measurements using the first and second approximations. The Rouse theory was more closely followed with the second approximation.     

Development of a Tool Database Management System

This paper describes a systematic approach to the design and development of a tool management system for the valve production unit of Bharat Heavy Electricals Limited (BHEL) located in Trichirapalli, India. The salient features of the design and development of a centralised database for tools that contains information regarding tooling, tool location, allo-cation, tool flow, tool storage and retrieval, parts, machines, etc. are discussed. It is estimated that the system being developed will significantly reduce the downtime of machines due to unavailability of the appropriate tools.     

Design and Implementation of Computer Integrated Manufacturing in Small and Medium-Sized Enterprises: A Case Study

* , Company A, to develop a practical framework for the implementation of CIM in SMEs.