Effect of cooking and drying on the thermal conductivity of rice

The transient line source technique was used to determine the thermal conductivity of rice during cooking and drying of cooked rice. A temperature range of 50‐70°C, moisture content of 10‐70% (wet basis), bulk (packing) density range of 500‐850 kg/m³ and porosity range of 0.265‐0.7 were studied. Thermal conductivity increased with increasing temperature, moisture content and bulk density, and the values were in the range 0.082‐0.543 W/m °C. This value is comparable with the literature values for granular and gelatinized starch. The data on the effect of phase change due to gelatinization have also been included. The experimental values were statistically analyzed and empirical polynomial equations were developed in terms of temperature, bulk density, porosity and moisture content of rice during cooking and drying the cooked material.     

Comparative Pharmacognostic Evaluation and HPTLC Analysis of Petals of Spiny and Non-Spiny Safflower Cultivars

To establish the identity and quality of safflower petals used as herbal tea, four spiny and non-spiny cultivars (APRR3, TSF-1, NARI-NH-01, and NARI-06) were analyzed for various pharmacognostic characters, toxic metals (As, Pb, Hg, Cr, Cd by atomic absorption spectroscopy), pesticide residue (GC-ECD/PFPD), and flavonoid constituents, like quercetin, quercetin-3-O-rutinoside, and kaempferol, by high performance thin layer chromatography. Arsenic and lead were found to be absent in the decoction of all varieties. Although mercury and chromium were detected in standard acceptable levels, cadmium was exceeding the limit except in APRR3 (0.3 mg/kg). While none of the samples contained pesticide residue and saponins, presence of tannins (19–25%), bitterness principle (1257–2200 units/g), mucilaginous substances (0.93–2.83 mL/g), and volatile matter (4–16%) were observed and estimated in all varieties. Microscopic examination of NARI-06 and APRR3 petals explored similar features having slightly thick cylindrical style with dense spikes and corolla tube with five slightly thick ridges possessing ribbon like outgrowths. High performance thin layer chromatography analysis revealed APRR3 to possess higher amount of quercetin (116.6 ng/g), quercetin-3-O-rutinoside (189.7 ng/g), and kaempferol (185.07 ng/g). Thus, the spiny APRR3 safflower petals encompassing anti-oxidative flavonoids and complying heavy metals test, was identified as a safe variety for human consumption.     

Effect of incorporating whey protein concentrate into stevia‐sweetened Kulfi on physicochemical and sensory properties

In 50% sugar replaced with 0.05% stevia‐added Kulfi, whey protein concentrate (WPC) at 0, 2, 3 and 4% levels were separately incorporated. Increase in WPC level resulted in significant (P < 0.05) decrease in freezing point, melting rate, hardness and moisture percentage and significant (P < 0.05) increase in specific gravity, protein percentage and total calorie content in the product. Among 0, 2, 3 and 4% WPC‐added Kulfi, 3% WPC‐added Kulfi was adjudged as best by a panel of judges. Above 3% WPC addition, the product was very soft and possessed undesirable whey flavour.     

Blend of sharpness and strength on a ball nose endmill geometry for high speed machining of Ti6Al4V

The applications of titanium alloys are increasingly common at marine, aerospace, bio-medical and precision engineering due to its high strength to weight ratio and high temperature-withstanding properties. However, whilst machining the titanium alloys using the solid carbide tools, even with application of high pressure coolant, reduced tool life was widely reported. The generation of high temperatures at the tool–work interface causes adhesion of work material on the cutting edges, and hence, shorter tool life was reported. In order to reduce the high tool–work interface temperature-positive rake angle, higher primary relief and higher secondary relief were configured on the ball nose endmill cutting edges. Despite of careful consideration of tool geometry, after an initial working period, the growth of flank wear accelerates the high cutting forces followed by work material adhesion on the cutting edges. Hence, it is important to blend the strength, sharpness, geometry and surface integrity on the cutting edges so that the ball nose endmill would exhibit an extended tool life. This paper illustrates the effect of ball nose endmill geometry on high speed machining of Ti6Al4V. Three different ball nose endmill geometries were configured, and high speed machining experiments were conducted to study the influence of cutting tool geometry on the metal cutting mechanism of Ti-6Al-4V alloy. The high speed machining results predominantly emphasize the significance of cutting edge features such as K-land, rake angle and cutting edge radius. The ball nose endmills featured with a short negative rake angle of value ?5° for 0.05～0.06 mm, i.e. K-land followed by positive rake angle of value 8°, has produced lower cutting forces signatures for Ti-6Al-4V alloy.     

Prediction of transient thermo-mechanical behavior of the headstock assembly of a CNC lathe

The demand for high-speed/high-precision machine tools is rapidly increasing in response to the development of production technology that requires high-precision parts and high productivity. The thermal deformation of the machine tool structure plays a critical role on the accuracy of machining. Heat generation in the bearings, chucking cylinder, and motor coil are the major sources of thermal deformation. This paper addresses the issues of the thermal displacements in the headstock assembly of a slant bed two-axis CNC lathe. Experimental and numerical investigations were carried out to gain insights into the extent of contribution made by the elements of the headstock assembly on the transient temperature rise and the resulting thermal deformation characteristics. The outcome of the work could be effectively used to improve the machine performance either by making suitable design changes or developing a robust error model for resorting to error compensation.     

Mixed convection flows of tangent hyperbolic fluid past an isothermal wedge with entropy: A mathematical study

The nonlinear, steady, and mixed convective boundary layer flow and heat transfer of an incompressible tangent hyperbolic non-Newtonian fluid over an isothermal wedge in the presence of magnetic field are analyzed numerically using the implicit Keller-Box finite-difference technique. The entropy analysis due to MHD flow of a tangent hyperbolic fluid past an isothermal wedge and viscous dissipation is also included. The numerical code is validated with previous Newtonian studies available in the literature. Graphical and tabulated results are analyzed to study the behavior of the fluid velocity, temperature, concentration, shear stress, heat transfer rate, entropy generation number, and Bejan number for various emerging thermophysical parameters, namely Weissenberg number (We), power-law index (n), mixed convection parameter (λ), pressure gradient parameter (m), Prandtl number (Pr), Biot number (γ), Hartmann number (Ha), Brinkmann number (Br), Reynolds number (Re), and temperature gradient (Π). It is observed that velocity, entropy, Bejan number, and surface heat transfer rate are reduced with the increase in the Weissenberg number, but temperature and local skin friction are increased. An increase in pressure gradient enhances velocity, entropy, local skin friction, and surface heat transfer rate, but reduces temperature and Bejan number. An increase in an isothermal power-law index (n) is observed to increase velocity, Bejan number, and surface heat transfer rate, but it decreases temperature, entropy, and local skin friction. An increase in the magnetic parameter (Ha) is found to decrease temperature, entropy, surface heat transfer rate, and local skin friction, and it increases velocity and Bejan number. The research is applicable for coating materials in chemical engineering, for instance, robust paints, production of aerosol deposition, and water-soluble solution thermal treatment.     

Evaluation of Nano Zinc (ZnO) for Surface Enhancement of ATR–FTIR Spectra of Butter and Spread

The effect of nano zinc (ZnO) particles in surface enhancement of attenuated total reflection–Fourier transform mid-infrared spectroscopy (ATR–FTIR) has been studied in butter and spread. Due to the health implications associated with consumption of trans fats, the studies also included the determination of band corresponding to trans fats of butter/spread in the nano-zinc-treated samples. The FTIR spectra of nano-zinc-treated butter showed enhancement of bands related to (―C―O, ―CH₂―) at wave number 1,238 cm⁻¹ and (O―C―C) band of esters at wave number 1,100 cm⁻¹. Shifting in wave number to 1,150 cm⁻¹ and reduction in its peak intensity was observed with the band corresponding to 1,162 cm⁻¹ (―C―O stretch). Reduction in peak intensity of the bands at about 2,915 and 2,850 cm⁻¹ (C―H groups) was also observed. In the case of spread, nano zinc reduced the peak intensities of FTIR bands at 2,915 cm⁻¹, 2,850 cm⁻¹ (―C―H― (CH₂) stretches), 1,746 cm⁻¹ (―C═O ester), 1,465 cm⁻¹ (―C―H (CH₂, CH₃)), 1,375 cm⁻¹ (―C―H (CH₃)) and 1,156 cm⁻¹ (C―O, ―CH₂). Trans fats band corresponding to ═C―H stretch (trans bonds, 966 cm⁻¹), was observed in pure butter and spread. Trans fatty acids in butter and spread were quantified with the aid of calibration/validation standards using trielaidin and triolein and by using partial least squares regression analysis. However, the band at 966 cm⁻¹ was hindered in Zn-treated butter and reduced in Zn-treated spread.     

Effects of dietary consumption of cranberry powder on metabolic parameters in growing rats fed high fructose diets

The effect of dietary consumption of a cranberry powder (CP) containing increased amounts of procyanidins and other phytochemicals on metabolic parameters associated with metabolic syndrome was investigated in growing rats fed a high fructose diet. Dietary treatments were control (starch based), high fructose (HF), and HF containing either 3.3, 6.6, or 33 g CP/kg diet. Fasting plasma glucose and triglycerides tended to be higher with HF feeding and were reduced by feeding CP. The area under curve following an oral glucose tolerance test was 35-50% higher in animals fed HF diet vs. control and was decreased to control levels by the low or medium but not high CP diet. Feeding CP tended to lower fasting plasma insulin. Homeostatic models of insulin resistance (HOMA-IR) and β-cell function (HOMA-BCF) were lowest in animals fed low or medium CP diets (p < 0.05). Rats fed the control starch diet had slightly higher food intake, final body weight, and abdominal fat compared to animals fed other diets. Kidney weight was higher in HF group and feeding CP decreased kidney weight to normal levels. In the fed state, plasma triglyceride was increased with HF diet, whereas insulin was lower in animals fed HF diet. Overall, inclusion of CP in the diet was effective in modulating some aspects of metabolic parameters associated with metabolic syndrome and the medium level of CP in the diet produced a better response than the lower and higher CP levels.     

Novel methyl cellulose‐grafted‐acrylamide/gelatin microspheres for controlled release of nifedipine

Naturally available carbohydrate polymers such as methylcellulose (MC) and gelatin (Ge) have been widely studied in the previous literature for controlled release (CR) applications. In this study, methyl cellulose‐g‐acrylamide/gelatin (MC‐g‐AAm/Ge) microspheres were prepared by water‐in‐oil (W/O) emulsion method and crosslinked with glutaraldehyde to encapsulate with nifedipine (NFD), an antihypertensive drug. The microspheres prepared were characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and laser particle size analyzer. DSC thermograms of NFD‐loaded AAm‐MC/Gel microspheres confirmed the molecular level distribution of NFD in the matrix. SEM indicated the formation of spherical particles. Swelling experiments supported the drug diffusion characteristics and release data of the matrices. Cumulative release data were analyzed using an empirical equation to understand the nature of transport of drug through the matrices. Controlled release characteristics of the matrices for NFD were investigated in pH 7.4 media. Drug was released in a controlled manner up to 12 h. Particle size and size distribution of the microspheres as studied by laser light diffraction particle size analyzer indicated their sizes to be around 120 μm. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010