Rapid Oscillations in Cataclysmic Variables. XV. HT Camelopardalis (= RX J0757.0+6306)

We present photometry and spectroscopy of HT Camelopardalis, a recently discovered X-ray-bright cataclysmic variable. The spectrum shows bright lines of H, He I, and He II, all moving with a period of 0.059712(1) d, which we interpret as the orbital period. The star's brightness varies with a strict period of 515.0592(2) s, and a mean full amplitude of 0.11 mag. These properties qualify it as a /bona fide/ DQ Herculis star (intermediate polar) -- in which the magnetism of the rapidly rotating white dwarf channels accretion flow to the surface. Normally at V=17.8, the star shows rare and very brief outbursts to V=12-13. We observed one in December 2001, and found that the 515 s pulse amplitude had increased by a factor of ~100 (in flux units). A transient orbital signal may also have appeared.Comment: PDF, 19 pages, 3 tables, 6 figures; accepted, in press, to appear June 2002, PASP; more info at http://cba.phys.columbia.edu

Dairy foods and dairy protein consumption is inversely related to markers of adiposity in obese men and women

A number of intervention studies have reported that the prevalence of obesity may be in part inversely related to dairy food consumption while others report no association. We sought to examine relationships between energy, protein and calcium consumption from dairy foods (milk, yoghurt, cheese, dairy spreads, ice-cream) and adiposity including body mass index (BMI), waist (WC) and hip circumference (HC), and direct measures of body composition using dual energy X-ray absorptiometry (% body fat and abdominal fat) in an opportunistic sample of 720 overweight/obese Australian men and women. Mean (SD) age, weight and BMI of the population were 51 ± 10 year, 94 ± 18 kg and 32.4 ± 5.7 kg/m2, respectively. Reduced fat milk was the most commonly consumed dairy product (235 ± 200 g/day), followed by whole milk (63 ± 128 g/day) and yoghurt (53 ± 66 g/day). Overall dairy food consumption (g/day) was inversely associated with BMI, % body fat and WC (all p < 0.05). Dairy protein and dairy calcium (g/day) were both inversely associated with all adiposity measures (all p < 0.05). Yoghurt consumption (g/day) was inversely associated with % body fat, abdominal fat, WC and HC (all p < 0.05), while reduced fat milk consumption was inversely associated with BMI, WC, HC and % body fat (all p < 0.05). Within a sample of obese adults, consumption of dairy products, dairy protein, and calcium was associated with more favourable body composition

Comparison of batch and continuous ultrasonic emulsification processes

AbstractBatch and continuous ultrasonic emulsification processes on both lab and pilot scales were investigated using Tween 80 or milk protein isolate (MPI) as emulsifiers. The process parameters of processing volume, residence time and ultrasonic amplitude, as well as emulsion formulations, emulsifier type and concentration, were studied for the effect on emulsion droplet size. Emulsions prepared with ultrasound yielded submicron droplets, ∼200nm, with Tween 80 and MPI, utilising all processing methodologies. Inverse power laws were obtained correlating emulsion droplet size with respect to energy density, highlighting the efficiency of the continuous over batch processing. This efficiency is ascribed to the smaller processing volumes, associated with continuous ultrasonic emulsification. Longer processing times were required for MPI to achieve submicron droplets (<200nm) in comparison to Tween 80 as greater times are necessary for interfacial adsorption and surface stabilisation, shown by interfacial tension measurements

The effect of ultrasound treatment on the structural, physical and emulsifying properties of animal and vegetable proteins

AbstractThe ultrasonic effect on the physicochemical and emulsifying properties of three animal proteins, bovine gelatin (BG), fish gelatin (FG) and egg white protein (EWP), and three vegetable proteins, pea protein isolate (PPI), soy protein isolate (SPI) and rice protein isolate (RPI), was investigated. Protein solutions (0.1–10 wt.%) were sonicated at an acoustic intensity of ∼34 W cm−2 for 2 min. The structural and physical properties of the proteins were probed in terms of changes in size, hydrodynamic volume and molecular structure using DLS and SLS, intrinsic viscosity and SDS-PAGE, respectively. The emulsifying performance of ultrasound treated animal and vegetable proteins were compared to their untreated counterparts and Brij 97.Ultrasound treatment reduced the size of all proteins, with the exception of RPI, and no reduction in the primary structure molecular weight profile of proteins was observed in all cases. Emulsions prepared with all untreated proteins yielded submicron droplets at concentrations ≤1 wt.%, whilst at concentrations >5 wt.% emulsions prepared with EWP, SPI and RPI yielded micron sized droplets (>10 μm) due to pressure denaturation of protein from homogenisation. Emulsions produced with sonicated FG, SPI and RPI had the similar droplet sizes as untreated proteins at the same concentrations, whilst sonicated BG, EWP and PPI emulsions at concentrations ≤1 wt.% had a smaller droplet size compared to emulsions prepared with their untreated counterparts. This effect was consistent with the observed reduction in the interfacial tension between these untreated and ultrasound treated proteins