Effect of ultrasonic amplitude on the general properties of w/o emulsion controlled-release coagulant and the quality enhancement of brine tofu

Barramundi skin, a by-product of the fish processing industry, has shown potential as an alternative collagen source. However, the commonly used acid extraction method to produce collagen rendered a low yield requires a lengthy time and is not environmentally friendly. As a result, the adoption of greener technology, such as ultrasound, to improve the conventional extraction process is emerging. This study aimed to investigate the effect of different ultrasonication amplitudes on collagen recovery from barramundi skin. The resulting collagens were evaluated for their protein, hydroxyproline and moisture content, colour, molecular weight distribution, and FTIR spectra. Ultrasound-assisted extraction (UAE) was performed at 40 (UAE40), 60 (UAE60) and 80 (UAE80) % amplitude for 20 min. For comparison, acetic acid extraction was also carried out to produce acid-soluble collagen (ASC). UAE increased the yield (p<0.05) of collagen from barramundi skin, with UAE80 exhibiting a 7-fold increment compared to ASC. Increasing the ultrasonic amplitude increased the yield considerably but decreased the hydroxyproline content, indicating a reduction in collagen quality. Furthermore, the protein content and SDS-PAGE profile of the extracted collagens revealed that UAE promoted protein degradation. FTIR spectra indicated that despite slightly varying wavenumbers, no detrimental effect on the triple helical structure was seen following UAE with the presence of amides A, B, I, II, and III. Also, the α1, α2 and ß-chains were found in all samples, although the band intensity reduced as the amplitude increased. In conclusion, given the right conditions, UAE could improve the extraction yield without influencing the collagen structure.

Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It is a simple and low cost method to produce bioactive material. This work describes the effect of ultrasonic amplitude on the surface properties of anodised titanium. Specifically, high purity titanium foils were anodised in mixture of 0.04 M β-glycerophosphate disodium salt pentahydrate (β-GP) and 0.4 M calcium acetate monohydrate (CA) at 350 V and 70 mA.cm-2 for 10 minutes. The ultrasonic amplitude was varied from 20-60 μm. Next, field emission scanning electron microscopy (FESEM) glancing angle X-ray diffractometer (GAXRD) and atomic force microscopy (AFM) were used to characterise the anodised titanium. The results showed that application of sonication is able to remove the entrapped bubbles on the anode surface and enhance the oxidation process. The pores size and surface roughness were increased as increasing of ultrasonic amplitude. At ultrasonic amplitude ≥ 50 μm, rutile TiO2 was formed on the surface of oxide layer. It was found that the sonication is a simple method to improve the surface properties of anodised titanium for implant applications.

Effects of kernel hardness and moisture content on wheat breakage in the single kernel characterisation system

Iron particles in air burn in heterogeneous combustion mode and the flame speed is very sensitive to particle size. Previous numerical work on the propagation of flames in iron dust was based on average particle sizes. However, in practice, experiments are conducted with particle size distributions (PSD). This makes it challenging to compare different experiments as the samples used in those studies vary (the average particle size might be similar but not the particle size distribution). It is the aim of the current work to provide insight into the effect of particle size distribution on flame propagation. This involves identifying the minimum number of discrete averaged particle sizes (bins) required in the simulations to capture the burning characteristics of the PSD. Then, flame speed and flame structure for a narrow and broad distribution are investigated. It is shown that the equivalence ratio at which the maximum flame speed occurs for certain mean particle sizes varies with the width of the particle size distribution. The difference in the flame speed between the same average particle size but different standard deviation varies as a function of β (ratio between standard deviation and average particle size), not just the average particle size itself. For a constant β at a particular equivalence ratio, the difference in the flame speed between PSD and mono-dispersed aerosols is approximately the same irrespective of the particle size. The effects of the smaller and bigger particles in the PSD on the flame speed and flame structure are also systematically investigated. The findings in this study confirm that the particle width of the PSD plays a crucial role and that experiments and simulations can not be readily compared if different PSDs are used.

Cashew nut shell liquid based polymer latexes of narrow size distribution and average particle sizes ranging from 0.1 to 0.4 µm were prepared by base catalysed emulsion polycondensation of cashew nut shell liquid of 820 centipoises viscosity with formaldehyde. The influence of emulsifier concentration, sodium hydroxide concentration and stirring rate on average particle size and size distribution was studied for the given geometry of the reactor and the stirrer. It was found that these variables have a significant effect on the particle size and particle size distribution and that average particles size can be predicted and controlled by the choice of these experimental variables. Interrelationships between these variables appear to be complex, however the apparent monotonic variation of average particle size with emulsifier concentration makes emulsifier concentration the most convenient parameter of controlling particle size. The influence of the type of mixers and various reaction kettle designs on the polymer particles' sizes should be studied. Tanzania Journal of Science Vol. 31 (1) 2005: pp. 35-44

In this study, waste ITO target is dissolved into hydrochloric acid to generate a complex acid solution. Nano-sized ITO powder with the average particle size below 50 nm is generated from this complex solution by spray pyrolysis process. This study also examines the influences of reaction parameters such as nozzle tip size and air pressure on the properties of the generated ITO powder. When the nozzle tip size is at 1 mm, the particle size distribution becomes more uniform in contrast to the case of other tip sizes, and the average particle size is around 50 nm. When the nozzle tip size increases up to 5 mm, the average particle size increases slightly, yet the particle size distribution becomes extremely irregular. Along with the change of nozzle tip size, the changing tendencies of XRD peak intensity and specific surface area are almost consistent with that of average particle size. Along with the increase of air pressure, the average particle size of the ITO powder gradually decreases, and the particle size distribution becomes more uniform. When the air pressure is at 0.1 kg/cm2, the particle size distribution appears extremely irregular, yet the average particle size is around 70 nm. When the air pressure is at 3 kg/cm2, the average particle size decreases down to 40 nm. Along with the increase of air pressure, the XRD peak intensity gradually decreases and the specific surface area increases.

ABSTRACTThe particle size analysis of maize, sorghum and millet under wet grinding conditions was studied with a burr grinding mill (the type commonly used in the locality). Some constants regarding particle size and size distribution of the wet ground products such as the distribution modulus, the size modulus, and the geometric mean diameter were determined.The ground material was wet seived in BS410 sieves with the aid of a dispersing agent, Calgon, which improved sieving, especially in the lower sieves.The results of the dried sieve fractions were plotted as cumulative percent by weight versus particle diameter on a log‐probability paper for the study of the particle size and size distribution characteristics. The geometric mean diameter (average particle size) of the ground product was observed to decrease with increase in moisture content, except that for maize which showed an initial rise before decrease. The size modulus, too, decreased with increase in moisture content but maize showord the usual deviation at the sian of soaking in water. The distribution modulus in maize and sorghum was seen to decrease with increase in moisture content but that of millet increased slightly.

The preparation of nano size nickel oxide powder by spray pyrolysis process

Acceleration mechanism of abrasive particle in ultrasonic polishing under synergistic physical vibration and cavitation: Numerical study

Shielding gas is an important parameter in Gas Metal Arc Welding (GMAW). Nevertheless, the influence of shielding gas on particle composition and size distribution of welding aerosols is not clearly understood. Increasing the O2 or CO2 content of Ar-based shielding gases resulted in an increase in the average particle size. For binary and ternary Ar, CO2, O2 mixtures, increasing CO2 had a greater impact than raising O2 on particle size. Variations in Ar–He–CO2 mixtures had the least influence. For 100% CO2, the particle size distribution was altered significantly due to the change of the weld transfer mode to globular and particle size coarsened with increasing arc voltage. Shielding gas composition had no observable influence on particle composition and only a slight variation of composition with particle size was observed. Particles were identified as (Fe,Mn)3O4 with trace additions of Si.

Due to the differences in mechanical properties of Al and SiC particles, the problems of SiC particle pullout and high surface roughness will occur in the processing of SiCp/Al composites. However, the ultrasonic vibration-assisted grinding of SiCp/Al can effectively decrease the appearance of such problems. A comparative experimental study of the ultrasonic vibration-assisted and ordinary grinding of SiCp/Al is conducted. First, the effect of ultrasonic amplitude on the removal form of SiC is summarized by observing the surface morphology of the sample. Then, the primary reasons for the pullout of SiC particles and high surface roughness in SiCp/Al processing are analyzed. The variation law of the surface roughness of SiCp/Al under different ultrasonic amplitudes and grinding parameters is summarized through a single-factor experiment. The results show that ultrasonic vibration-assisted grinding is beneficial for reducing the surface roughness of SiCp/Al. When grinding linear speed of grinding wheel vs increases from 2.512 m/s to 7.536 m/s, surface roughness Ra decreases from 0.25 µm to 0.16 µm. when feed rate vw increases from 100 mm/min to 1700 mm/min, surface roughness Ra increases from 0.13 µm to 0.20 µm. When grinding depth ap increases from 0.01 mm to 0.05 mm, surface roughness Ra increases from 0.13 µm to 0.19 µm. When ultrasonic amplitude A is increased from 0 µm to 2 µm, surface roughness Ra decreases from 0.26 µm to 0.15 µm. When ultrasonic amplitude A is increased from 2 µm to 4.4 µm, surface roughness Ra increases from 0.15 µm to 0.18 µm.

Effect of ultrasonic amplitude and riveting speed on mechanical properties of Ti-45Nb riveted lap joints

A novel EDM method using longitudinal-torsional ultrasonic vibration (LTV) electrodes to improve machining performance for micro-holes

In this study, nano-sized indium oxide powder with the average particle size below 100 nm is fab-ricated from the indium chloride solution by the spray pyrolysis process. The effects of the reaction temperature, the concentration of raw material solution and the inlet speed of solution on the properties of powder were studied. As the reaction temperature increased from 850 to 1000°C, the average particle size of produced powder increased from 30 to 100 nm, and microstructure became more solid, the particle size distribution was more irregular, the intensity of a XRD peak increased and specific surface area decreased. As the indium concentration of the raw material solution increased from 40 to 350 g/l, the average particle size of the powder gradually increased from 20 to 60 nm, yet the particle size distribution appeared more irregular, the intensity of a XRD peak increased and spe-cific surface area decreased. As the inlet speed of solution increased from 2 to 5 cc/min., the average particle size of the powder decreased and the particle size distribution became more homogeneous. In case of the inlet speed of 10 cc/min, the average particle size was larger and the particle size distribution was much irregular compared with the inlet speed of 5 cc/min. As the inlet speed of solution was 50 cc/min, the average particle size was smaller and microstructure of the powder was less solid compared with the inlet speed of 10 cc/min. The intensity of a XRD peak and the variation of specific area of the powder had the same tendency with the variation of the average par-ticle size.

In our recent work, we synthesize several spherical rutile TiO2 powders with different average particle size though hydrothermal method using TiCl4 under lower temperature in a shorter reaction period. Afterwards, solar heat-reflection coatings were prepared by using the TiO2 as pigment. The TiO2 powders were characterized by XRD to determine the phase of crystal. The morphology and particle size were observed by using SEM, and the spectral reflectance of the powder samples and coatings were measured using UV/VIS/NIR spectrophotometer. In order to measure the temperature on the back of coatings, the self-assembled equipment which consisted of solar lamps and surface temperature sensors connected to a data logging system was invented. The test results showed that the shape, average particle size and size distribution were closed-packed state and a bigger mean particle size had higher reflectance intensity. Meanwhile, the reflectance was closely connected to the particle size distribution. Actually, the coatings dispersed TiO2 powder with desired size distribution had excellent performance.