Quantification of the energy required for the destruction ofBalanus amphitritelarva by ultrasonic treatment

2010 ◽  
Vol 90 (7) ◽  
pp. 1475-1482 ◽  
Author(s):  
Nishant Seth ◽  
Piyul Chakravarty ◽  
Lidita Khandeparker ◽  
Arga Chandrashekar Anil ◽  
Aniruddha B. Pandit
Keyword(s):  
Power Density ◽  
Ultrasonic Treatment ◽  
Bacterial Abundance ◽  
Treatment Time ◽  
Power Level ◽  
Acoustic Power ◽  
Water Disinfection ◽  
Balanus Amphitrite ◽  
Marine Fouling ◽  
System Operating

Ultrasonic treatment, a relatively less explored technology in water disinfection, was used to quantify the energy required for the destruction of larvae of barnacleBalanus amphitrite, which is a major marine fouling and a potential invasive organism. Since the power used and treatment time for disinfection are economically, and practically, the most important parameters, the energy required to pulverize the larvae into pieces ≤30 µm was determined as a function of the acoustic power density. The present investigation suggests that an ultrasonic system operating at 20 kHz and 0.0975 W/cm3can effectively pulverize barnacle larvae having length (~440 µm) and breadth (~350 µm) within 45 seconds using 0.1 mJ/larva of pulverization energy. It was also observed that following pulverization of the larvae, the bacterial abundance increased and the rate of release of bacteria was dependent on power level and treatment time, which in turn decided the pulverization rate and hence the rate of release of bacteria.

scholarly journals Skarn-scheelite ores beneficiation stimulation using ultrasonic treatment

2018 ◽  
Vol 56 ◽  
pp. 03009 ◽  
Author(s):  
Elena Shepeta ◽  
Luiza Samatova
Keyword(s):  
Ultrasonic Treatment ◽  
Treatment Time ◽  
Heating Temperature ◽  
Chemical Properties ◽  
Sound Intensity ◽  
Acoustic Power ◽  
Circulating Water ◽  
Plant Processing ◽  
Physical And Chemical ◽  
The Impact

The impact of acoustic vibrations on physical and chemical properties of circulating water, heterogenic systems of pulps of sulphide and scheelite cycles flotations, collectors (IMA-I413p (potassium butyl xanthate), sodium oleate of commercial acid B-115) have been studied on skarn scheelite-quartz-sulphide ore of Vostok-2 deposit. Ultrasonic treatment has been performed using UZDN-2T apparatus. Working frequency 22 kHz, absorbed acoustic power average for radiator Pak = 46 W, sound intensity average Ius = 1 W/cm2 (rated Ius= 2-3 W/cm2). During all experiments, ultrasonic treatment time was constant - 5 minutes, insonation solutions volume - 250-100 ml, solutions heating temperature in the course of insonation - 25-35 °С. The flotation tests patterns, reagent scheme are approximate to process regulation of Primorskaia oreprocessing plant processing ores of given deposit. Utmost increment of extraction in case of collctors ultrasonic treatment has been reached on dialkyldithiophosphate (IMA-I413p), the increment of extraction of chalcopyrite into bulk sulphide concentrate 0.98 %. The best results of testing of ultrasonic treatment impact on scheelite ores beneficiation have been obtained in case of ultrasound impact on circulating water. In consequence of stimulation of precious minerals flotation increment of extraction of chalcopyrite into copper concentrate by 1.4 % and scheelite into bulk rough concentrate by 2.5 % has been obtained.

scholarly journals Finish drying and surface sterilization of bay leaves by microwaves

2018 ◽  
Author(s):  
Parag Prakash Sutar ◽  
Ashish Kapoor
Keyword(s):  
Microwave Heating ◽  
Power Density ◽  
Water Activity ◽  
Treatment Time ◽  
Color Change ◽  
Power Level ◽  
Colour Change ◽  
Microwave Treatment ◽  
Microbial Reduction ◽  
Surface Sterilization

Bay leaves (Laurus nobilis L.) refers to aromatic leaves which are native to minor regions of Asia. In order to extend the shelf life of the bay leaves its water activity and the surface micro-organisms were reduced using microwave heating at different power densities in the range 32.14 to 142.85 Wg-1. Treatment time at each power level was maintained constant at 150 s. The maximum reduction in water activity and moisture content occurred at highest power density. The heating time-temperature profile was obtained at all  power levels. TPC, color change and browning index (BI) of bay leaves were measured in order to determine the effect of microwave treatment on microbial reduction and quality. The highest reduction in TPC was found in leaves heated at 142.85 Wg-1 power density along with acceptable quality parameters of the treated bay leaves. Keywords: Bay leaves; Microwave heating; TPC; Colour change 

Microstructure and Mechanical Properties of Mg-6Zn-1.4Y Alloy Produced by Rheo-Squeeze Casting Process

2016 ◽  
Vol 879 ◽  
pp. 530-535
Author(s):  
Xiao Gang Fang ◽  
Shu Sen Wu ◽  
Shu Lin Lü
Keyword(s):  
Mechanical Properties ◽  
Power Density ◽  
Squeeze Casting ◽  
Casting Process ◽  
Acoustic Power ◽  
Icosahedral Quasicrystal ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Grain Size And Shape ◽  
Semi Solid

Mg-Zn-Y alloys containing a thermally stable icosahedral quasicrystal phase (I-phase) will have wide application future on condition that primary α-Mg dendrite and the I-phase can be refined during the casting process. In this research, the microstructure and mechanical properties of the rheo-squeeze casting (RSC) Mg-6Zn-1.4Y alloys have been investigated. The Mg alloy melt was exposed to ultrasonic vibration (USV) with different acoustic power densities from 0 W/mL to 9 W/mL, and then the slurry was formed by squeeze casting. The results show that good semi-solid slurry with fine and spherical α-Mg particles could be obtained with the acoustic power density of 6 W/mL, and the average grain size and shape factor of primary α-Mg were 32 μm and 0.76, respectively. Meanwhile the coarse eutectic I-phase (Mg3Zn6Y) was refined obviously and dispersed uniformly. Compared with the samples without USV, the tensile strength and elongation of the RSC casting samples with 6 W/mL acoustic power density were elevated by 10.6% and 55.5%, respectively.

scholarly journals Supersonic Windtunnel Noise Attenuation

2021 ◽  
Author(s):  
William Wai Lim Wong
Keyword(s):  
Wind Tunnel ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Power Level ◽  
Mesh Size ◽  
Acoustic Power ◽  
Pressure Level ◽  
Supersonic Wind Tunnel ◽  
Acoustic Treatment

The aerodynamic generated noise in the supersonic wind tunnel during operation at Ryerson University has exceeded the threshold of hearing damage. An acoustic silencer was to be designed and added to the wind tunnel to reduce the noise level. The main sources of noise generated from the wind tunnel with the silencer were identified to be located at the convergent divergent nozzle and the turbulent region downstream of the shock wave at the diffuser with the maximum acoustic power level of the entire wind tunnel at 161.09 dB. The designed silencer provided an overall sound pressure level reduction of 21.41 db which was considered as acceptable. Refinement to the mesh size and changes to the geometry of the mixing chamber was suggested for a more accurate result in noise output as well as flow conditions would match up to the physical flow. Additional acoustic treatment should be applied to the wind tunnel to further reduce sound pressure level since the noise level still exceeded the threshold of hearing loss.

scholarly journals Enhancement of flaky graphite cleaning by ultrasonic treatment

2019 ◽  
Vol 6 (12) ◽  
pp. 191160 ◽  
Author(s):  
Wenze Kang ◽  
Huijian Li
Keyword(s):  
Carbon Content ◽  
Ultrasonic Treatment ◽  
Treatment Time ◽  
Treatment Technique ◽  
Particle Sizes ◽  
Cleaning Process ◽  
Flotation Concentrate ◽  
Metal Impurities ◽  
Pre Treatment ◽  
Ultrasound Power

In this study, the aim is to simplify the graphite cleaning process. In order to achieve flotation for graphite effectively, ultrasonic treatment was used as a pre-treatment technique. Flotation tests were conducted using different ultrasound power and ultrasonic treatment time. The influences of ultrasonic treatment on particle sizes, morphologies, wettability, the content of surface elements and on the flotation effect of flaky graphite were investigated. The results of ultrasonic treatment for graphite flotation were compared with the results of conventional flotation. The results showed that ultrasonic treatment not only changed the size of flaky graphite, but also eliminated impurities on the graphite surface. Additionally, the ultrasonic treatment improved the hydrophobicity of graphite. It was observed that ultrasound can remove not only silicate impurities but also most other metal impurities. The yield, carbon content and recovery of flotation concentrate were 91.46%, 95.17% and 96.12% after ultrasonic treatment for 4 min with ultrasound power 1600 W, which were 5.83%, 2.86% and 8.84% higher than that of conventional flotation, respectively. The graphite after ultrasonic treatment was conducted only one times flotation, the carbon content in concentrate products had reached 95%. This study indicates that intensifying graphite flotation by ultrasonic treatment can shorten the graphite cleaning process.

scholarly journals A comprehensive investigation of acoustic power level in a moderate or intense low oxygen dilution in a jet-in-hot-coflow under various working conditions

2019 ◽  
Vol 93 ◽  
pp. 105339 ◽  
Author(s):  
Seyed Mahmood Mousavi ◽  
Reza Kamali ◽  
Freshteh Sotoudeh ◽  
Reza Pourabidi ◽  
Nader Karimi ◽  
...  
Keyword(s):  
Working Conditions ◽  
Power Level ◽  
Acoustic Power ◽  
Low Oxygen ◽  
Comprehensive Investigation

Factors Influencing the Settling of the Principal Marine Fouling Organisms in Sydney Harbour

1959 ◽  
Vol 10 (1) ◽  
pp. 30 ◽  
Author(s):  
B Wisely
Keyword(s):  
Surface Water ◽  
Test Site ◽  
Horizontal Distance ◽  
Accurate Assessment ◽  
Balanus Amphitrite ◽  
Bugula Neritina ◽  
Marine Fouling ◽  
Factors Influencing ◽  
Sydney Harbour ◽  
Fouling Organisms

The macrofouling organisms most commonly encountered during intermittent plate exposures in Sydney Harbour over 10 years (1947-57) comprised a barnacle (mainly Balanus (Balanus) amphitrite var. cirratus Darwin), several serpulids and bryozoans (Hydroides norvegica Gunnerus, Spirorbis sp.; Bugula neritina L., Bugula avicularia L., Watersipora cucullata (Busk)), a mussel (Mytilus planulatus Lamarck), and an oyster (Crassostrea commercialis Iredale & Roughley). With the exception of the mussel, settlement was heaviest during the summer months. Surface water temperatures averaged from about 15°C in midwinter to 24� in midsummer and were over 20°C for 6 months of the year. Two cases where freshwater dilution apparently affected biological populations are recorded. The effects of colour, surface texture, depth, aspect, and horizontal distance on settling were investigated using paired series of plates. The results were treated statistically and compared with those reported by others. It is suggested that during antifouling raft tests at this locality the control plates for any group of experimental plates need to be placed at the same site, same depth, facing the same way, and 5-10 ft apart horizontally. Providing the most common macrofouling organisma settling at the station were considered as a whole, this arrangement seemed to give a reasonably accurate assessment of their settling intensity at the test site.

Effects of Process Parameters on the Particle Size Distribution of Graphene Oxide Aqueous Dispersion

2013 ◽  
Vol 750-752 ◽  
pp. 1113-1116 ◽  
Author(s):  
Xue Bing Hu ◽  
Yun Yu ◽  
Jian Er Zhou ◽  
Li Xin Song
Keyword(s):  
Particle Size ◽  
Graphene Oxide ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ultrasonic Treatment ◽  
Treatment Time ◽  
Aqueous Dispersion ◽  
Centrifugal Separation ◽  
Effective Particle Size ◽  
Effective Particle

During graphene oxide separation process, the effects of the process parameters such as centrifugal separation time and ultrasonic treatment time on the particle size distribution of graphene oxide aqueous dispersion were studied. The results show graphene oxide has the narrower particle size distribution and the smaller nominal effective particle size with increasing the centrifugal separation time from 20 min to 160 min. And there is a critical time in the ultrasonic treatment to obtain the narrower particle size distribution and smaller nominal effective particle size of graphene oxide. Graphene oxide has the narrower particle size distribution and the smaller nominal effective particle size when the ultrasonic treatment time is 4 h.

Superlattice Thin-film Thermoelectric Materials and Devices

2003 ◽  
Vol 793 ◽  
Author(s):  
Rama Venkatasubramanian ◽  
Brooks O'Quinn ◽  
Edward Siivola ◽  
Kip Coonley ◽  
Pratima Addepally ◽  
...  
Keyword(s):  
Thin Film ◽  
Power Density ◽  
Power Efficiency ◽  
Power Level ◽  
Active Device ◽  
Structured Materials ◽  
Conversion Unit ◽  
Small Footprint ◽  
Near Term ◽  
P Type

ABSTRACTThin-film nano-structured materials offer the potential to enhance the performance of thermoelectrics, with near-term capabilities like small-footprint coolers for lasers and microprocessors. Our recent focus has been to transition the enhanced figure-of-merit (ZT) in p-type Bi2Te3/Sb2Te3 and n-type Bi2Te3/Bi2Te3-xSex superlattices to performance at the module level with several device demonstrations. We have been able to obtain a best ZT of ∼2 in a p-n couple, the fundamental cooling or power conversion unit in an operational module. In addition, we have been able to demonstrate p-n couple ZT of as much as 1.6 from heat-to-power efficiency data. The thermal interface resistances between the active device and the external heat source have been optimized. A power level of 38 mW per couple for a ΔT of about 107K, with 4-micron-thick element, was obtained. This translates to an active power density of ∼54 W/cm2 and a mini-module power density of ∼10.5 W/cm2. In short, power devices with thin-film superlattices are a real possibility. In the cooling arena, we have been able to obtain over 50K active cooling with thin-film modules, useable in several laser and microprocessor cooling needs. This is in spite of severe thermal management issues that had to be overcome noting that the “true” hot-side temperature, and hence the “true” ΔT, across the device are much higher. Even so, we have p-n superlattice couples that show twice the cooling ΔTmax, compared to the best bulk p-n couples at cryogenic temperatures. Some of the challenges that remain to be addressed in the full development of this materials technology and thoughts on further progress in nano-structured materials are presented.

Ultrasonic Treatment of Nanostructured Powders for the Production of Zirconia Ceramics

1998 ◽  
Vol 520 ◽  
Author(s):  
O.L. Khasanov ◽  
Yu.P. Pokholkov ◽  
V.M. Sokolov ◽  
E.S. Dvilis ◽  
V.K. Strutz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Ultrasonic Treatment ◽  
Power Level ◽  
Volumetric Shrinkage ◽  
Zirconia Ceramics ◽  
Elastic Aftereffect ◽  
Nanostructured Powders

ABSTRACTThe structure and mechanical properties of Y-TZP nanoceramics produced by ultrasonic (US) action on nanostructured ZrO2 – 5.4wt% Y2O3 powder have been analyzed. The influence of powder US-treatment on elastic aftereffect of a compact, uniformity of ceramics volumetric shrinkage, on ceramic nanostructure forming and as a result on its density, hardness, impact strength was shown. The optimum of power level of US-action was defined.

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