Effect Of Ultrasonic Agitation Research Articles

Effect of ultrasonic agitation on marginal adaptation, intratubular penetration and bonding strength of calcium-silicate-based endodontic sealers: A laboratory study.

The effect of ultrasonic activation (UA) on marginal adaptation, intratubular penetration and bond strength provided by three calcium silicate-based sealers was evaluated. Ninety-six distobuccal root canals of maxillary molars were randomly divided into 8 groups (n = 12) according to the sealer and UA application: EndoSequence BC sealer (ESBC), Sealer Plus BC (SPBC) and Bio-C Sealer (BCS), using AH Plus (AH) as a control group. The specimens were sectioned at 2, 4 and 6 mm from the apex. The data were statistically analysed using Kruskall-Wallis, Dunn, Mann-Whitney and chi-squared tests. UA improved the marginal adaptation of ESBC (6 mm), SPBC (all levels), BCS (2/4 mm) and AH (4 mm) (p < 0.05); the bond strength of SBPC (2 mm) and BCS (6 mm) were also improved (p < 0.05). The UA of endodontic silicate-based sealers improved the marginal adaptation in all levels and the bond strength of SBPC and BCS sealer.

Effect of ultrasonic agitation on the penetration depth of different root canal sealers

Aim: The present in vitro study was taken to compare penetration depth of five different root canal sealers to radicular dentin by confocal laser scanning microscope. Materials and Methods: 100 extracted intact single- rooted human teeth were collected. Teeth were decoronated, shaping and cleaning was done with rotary file system till #25 number file with 0.06% taper. Half of the samples (n=50) were irrigated without ultrasonic agitation while other half (n=50) samples were irrigated with ultrasonically agitation. Teeth were obturated and divided into five groups on the basis of five different sealer used (Group A: Zinc oxide eugenol sealer (control group), Group B: Apexit Plus, Group C: AH Plus, Group D: MTA Fillapex, Group E: Bio-C sealer). Samples were sectioned horizontally at 2mm, 4mm and 6mm from the apical region and penetration depth was observed under confocal laser scanning microscope. Data obtained was statistically analysed using Independent t test and Tukey Test. Results: Among the groups, Bio- C sealer (Group E) revealed greatest penetration depth at 2mm and 4mm while zinc oxide eugenol (Group A) had the least penetration depth. Among the subgroups, samples irrigated with ultrasonic agitation showed rise in penetration depth of the sealers.

Study on the Effects of Ultrasonic Agitation on CO2 Adsorption Efficiency Improvement of Cement Paste

To realize high-efficiency CO2 absorption by fresh cement paste, ultrasonic vibration technology is introduced into the CO2 absorption test device used in this study. Influences of ultrasonic frequency on the CO2 absorption rate (CO2 AR) and the ultimate absorption amount of fresh cement paste are analyzed. Furthermore, the influencing laws of the CO2 absorption amount (CO2 AA) on the fluidity, pore distribution, and mechanical properties of cement paste under ultrasonic vibrating agitation are analyzed by measuring the variations of the CO2 AA of cement paste. Results demonstrate that ultrasonic vibrating agitation not only can increase the CO2 AR and ultimate absorption amount of fresh cement paste, but also can optimize the internal pore structure of materials and compressive strength of cement-based materials.

Using a triblock copolymer as a single additive in high aspect ratio through silicon via (TSV) copper filling

Through silicon via (TSV) is a promising interconnect technology in three-dimensional (3D) integration which has large packing density, improves efficiency and consumes less energy. Since the optimization process of multi-additives system is complicated to achieve void-free TSV copper filling, the use of a single additive become a new trend. In this paper, the using of a triblock copolymer ethylene oxide (EO) - propylene oxide (PO) - ethylene oxide (EO) as a single additive in TSV copper electrodeposition was investigated. High and low concentration of EPE (0.02 g/L and 0.002 g/L) were used for the filling experiment at different current densities. It was found that low concentration EPE had stronger inhibition ability, and achieved “V shape” filling at 0.3 ASD (A/dm2). However, EPE of high concentration would form micelles in electrolyte, resulting in the decrease of inhibition ability. We proposed a mechanism for the different EPE concentrations to explan the phenomenon. In addition, the effect of ultrasonic agitation on EPE filling performance was investigated. With the ultrasonic agitation, bottom-up filling can be achieved at 0.02 g/L, and filling rates can be increased at 0.002 g/L. This can be attributed to the cavitation of the ultrasound which can promote the mass transfer and clean the activated electrode.

Effect of Ultrasonic Agitation on the Microtensile Bond Strength for Cementing Ceramic Inlays

Effect of Ultrasonic Agitation on the Microtensile Bond Strength for Cementing Ceramic Inlays

Effect of Ultrasonic Agitation and Spin Coating Speed on the Photovoltaic Properties of Inverted Organic Solar Cell Using Solution-Dispersed Copper Iodide as Anode Buffer Layer

Previous study showed that the introduction of solution-dispersed copper iodide (CuI) as anode buffer layer has improved the performance of inverted type organic solar cell. However, the CuI preparation parameters have yet to be optimized for the inverted type organic solar cell. In this work, the effect of ultrasonic agitation of CuI solution on inverted type organic solar cell based on zinc oxide (ZnO)/poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C61-butyric acid methyl ester (PCBM) has been studied. ZnO, acting as electron transporter, was spin-coated on top of fluorine tin oxide (FTO) substrate, while the active layer consisting of P3HT:PCBM as the electron donor and electron acceptor was spin-coated onto the ZnO layer and the top electrode, silver (Ag) was then thermally evaporated. CuI dispersed in acetonitrile solution was ultrasonicated with durations of 10, 20 and 30 min and then was spin-coated on the active layer. It was found that solution-dispersed CuI with longer ultrasonic agitation duration attained a relatively higher PCE than that with shorter duration and the highest PCE was 2.13%, achieved at 30 min ultrasonic agitation due to good film surface morphology. For further optimization, the deposition of CuI was carried out using different spin coating speeds of 1000 and 3000 rpm. The optimum PCE obtained was 2.29 at a spin coating speed of 3000 rpm as a result of uniform layer of CuI.

Sonoelectrodeposition : Microstructural Studies in Aqueous and Ionic Liquid Electrolytes

Rare are the industrial examples of ultrasonic enhancement of the plating step itself. However, it has been demonstrated at laboratory scale that many advantages may be gained by use of ultrasound. Several authors such as Walker et al. (1973) [1] or Touyeras et al. [2] reported the beneficial effect of ultrasound in metal deposition and plating. This is particularly competitive as it may result in a reduction of chemical additives use, or even in their complete suppression. They also report that plating in an ultrasonic field may produce electrodeposits with an increased hardness and brightness, better adhesion to substrate, a finer grain and a reduced porosity and internal stress. Most of these properties are in direct relationship with the coating microstructure, which becomes therefore a major issue. Silver coating microstructures examined by XRD measurements reveals an important sensitivity of the crystalline preferential orientation to both current density and ultrasonic irradiation. Two main categories are identified by XRD: one poorly structured and the other following the [110] orientation, corresponding to low and high current densities. It is interesting to note that, while changing from still to mechanically stirred conditions, the value of the current density threshold moves from 2.5mA/cm² to 5mA/cm². When ultrasound is used (575 kHz or 20 kHz), this coating microstructure modification threshold occurs at higher current density values when coatings are produced under sonication, while agitation is kept at the same level (equivalent velocity). In both cases, the shift is about 15 mA/cm² [3]. It appears then as an interesting challenges to control the cavitation activity and especially the respective contribution from ultrasonic streaming vs. bubble collapse at the electrode vicinity [4]. This is possible by the use of the double reactor Besançon cell, filled with ionic liquids [5]. As ionic liquids present very low volatilities, their vaporization is reduced, and cavitation bubbles only depend on the presence of gases. Then, cavitation activity may be trigged by reactor atmosphere control. Applying severe depression within an irradiated ionic liquid medium contributes to removing dissolved gases, thus quenching progressively cavitation activity [6]. Electrolytes were prepared by dissolution of metallic salts composed by Tf2n as anion, and Copper or silver as cation in BuMIMTf2n, and deposits have been elaborated under various pressures (88, 55 and 26 kPa) to allow a progressive variation of the cavitation activity. All electrodepositions have been performed at a given potential, under the very same ultrasonic transmitted power. The charge was adapted to get the same thickness, and XRD measurements allow the comparison of crystalline preferential orientations. [1] C.T. Walker, R. Walker, Effect of ultrasonic agitation on some properties of electrodeposits, Electrodepos. Surf. Treat. 1 (1973) [2] F. Touyeras, J.Y. Hihn, X. Bourgoin, B. Jacques, L. Hallez, V. Branger, Effects of ultrasonic irradiation on the properties of coatings obtained by electroless plating and electro plating, Ultrason. Sonochem. 12 (2005) [3] A. Nevers, L. Hallez, F. Touyeras, J.-Y. Hihn, Effect of ultrasound on silver electrodeposition: Crystalline structure modification, Ultrason. Sonochem. 40 (2018) [4] J.-Y. Hihn, M.-L. Doche, A. Mandroyan, L. Hallez, B.G. Pollet, Respective contribution of cavitation and convective flow to local stirring in sonoreactors, Ultrason. Sonochem. 18 (2011) [5] C. Costa, J.-Y. Hihn, M. Rebetez, M.-L. Doche, I. Bisel, P. Moisy, Transport-limited current and microsonoreactor characterization at 3 low frequencies in the presence of water, acetonitrile and imidazolium-based ionic liquids, Phys. Chem. Chem. Phys. PCCP. 10 (2008) [6] B. Naidji, L. Hallez, A. EtTaouil, M. Rebetez, J.-Y. Hihn, Influence of pressure on ultrasonic cavitation activity in room temperature ionic liquids: An electrochemical study, Ultrason. Sonochem. 54 (2019) Figure 1

Effect of ultrasonic agitation during the activation process on the microstructure and corrosion resistance of electroless Ni-W-P coatings on AZ91D magnesium alloy

Two pretreatment method, including the normal activation and the ultrasonic agitation in acidic bath, were used during the pretreatment of AZ91D substrate, for which the electroless Ni-W-P coating was prepared. The microstructure, bonding strength and corrosion resistance were compared. The effect of different activation condition on the microstructure and corrosion resistance was investigated and discussed. Results demonstrate that ultrasonic agitation has negligible effect on the microstructure, chemical composition, but improves the bonding strength and corrosion resistance of Ni-W-P coating. The corrosion resistance of Ni-W-P coating via ultrasonic pretreatment was less dependent on the deposition time. Ultrasonic agitation facilitates the deposition of Ni on the β phase and the eutectic phase, and improves the compactness at Mg/Ni interface by decreasing the inclusion of MgF2, which are critical for improving the quality of Ni-W-P coating.

Influence of ultrasonic agitation on bond strength, marginal adaptation, and tooth discoloration provided by three coronary barrier endodontic materials.

The effect of ultrasonic agitation (UA) on bond strength and adaptation of cervical plugs prepared with MTA Angelus (MTA), MTA Repair HP (MTAHP), and Biodentine (BIO) was evaluated. Dentin discoloration caused by the materials/treatment was also assessed. Seventy-two single rooted teeth were divided into six groups depending on the materials/treatment. After cervical plug preparation, dentin discs were excised for the push-out test; additional discs were analyzed under the confocal microscope to determine adaptation (gaps occurrence). For dentin discoloration analysis (ΔE), blocks of bovine incisors had cavities prepared and filled with the materials/treatment (from 7 to 180days). Both bond strength and adaptation were positively influenced by UA (P < 0.05). Comparison between materials showed an advantage for BIO when compared to MTAHP (P < 0.05). The best and worst results were provided by BIO/UA (12.66MPa and 1.87%) and MTAHP (2.54MPa and 28.58%), respectively. For ΔE, significant differences were observed throughout the periods. Just the MTA without UA exhibited noticeable discoloration at 180days (P < 0.05). UA favored a better adaptation of the materials to the dentin root, resulting in higher bond strength and adaptation of the materials to the root canal walls. Moreover, UA reduced MTA discoloration, keeping it imperceptible over the period evaluated. The better adaptation and higher bond strength provided by UA can be considered clinically relevant due to the importance of maintaining blood clot integrity and the possible esthetic compromise provided by reparative materials when used as coronary barrier in regenerative procedures.

Process optimization of selective wet etching for fabrication of high-aspect-ratio and uniform multilayer grating reference materials

Background: The multilayer gratings are considered as the potential length-standard-traceable lateral scales for calibrating the next-generation critical dimension scanning electron microscope (CD-SEM) magnification. As a key step in the fabrication of multilayer gratings, selective wet etching determines the final grating structure formation. However, the effects of the etching process parameters on the multilayer gratings in several nanometer scales have not been reported in detail. Aim: By optimizing the process of selective wet etching, we should fabricate high-aspect-ratio and uniform multilayer gratings to obtain high-contrast secondary electron signals and stable secondary electron images while also obtaining measurement accuracy from the small line edge roughness. Approach: Based on the analysis of the important factors in the etching process and SEM and TEM measurement results, we evaluate the effects of ultrasonic agitation, HF acid concentration, etch time, and linewidth scale on the aspect-ratio and uniform of multilayer gratings. Results: We recommend to etching the multilayer films with an HF acid concentration of about 2% during the ultrasonic agitation for uniformity. Moreover, selective wet etching reaction is limited by scale when the linewidth is below 20 nm. Despite the fact that the grating structure is fragile and easy to be broken down, for linewidths of about 10 and 5 nm, the aspect ratio of multilayer gratings can reach about 3 and 2, respectively. Conclusions: By focusing on the optimum conditions of ultrasonic agitation, HF acid concentration, and linewidth scale in the selective wet etching, selective wet etching can be used to fabricate high-aspect-ratio and uniform multilayer gratings with linewidth below 20 nm.

New Insight into the Dissolution of Epoxy Resin–based Sealers

IntroductionThe purpose of this study was to evaluate the use of solvents that are not traditionally used in dentistry for the dissolution of an epoxy resin–based sealer and the effect of ultrasonic agitation (UA). MethodsThe dissolution of the AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) and the effect of UA in various solvents (eucalyptol, xylene, chloroform, EndoSolv R [Septodont, Cedex, France], EndoSolv E [Septodont], methyl ethyl ketone [MEK], and ethyl acetate) were quantified. The dissolving capacity was assessed by weight loss, Vicker microhardness, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results were compared with factorial analysis of variance using IBM SPSS Statistics 23.0 software (IBM, Armonk, NY), considering a 0.05 significance level. A preliminary ex vivo study was performed in extracted teeth, with MEK activated by UA as the final irrigation after mechanical removal of the filling material. SEM was used for assessing the cleanliness of the root canal walls. ResultsThe new solvent proposals, ethyl acetate and MEK, exhibited high dissolution ability, almost reaching chloroform. UA increased dissolution. Vicker values corroborated the dissolution assays. SEM and XRD revealed that solvents affected mainly the organic component of the sealer. Ex vivo results confirmed the immersion model findings. ConclusionsMEK and ethyl acetate proved to be excellent alternatives to chloroform or xylene solvents. MEK presented a high sealer dissolving ability in a short period, especially with UA, without the potential hazards of chloroform, suggesting it is a good approach to AH Plus sealer's dissolution empowered by UA. These results should encourage further studies in order to confirm their clinical relevance.

The effects of ultrasonic agitation on supercritical CO2 copper electroplating

Applying ultrasound to the electroplating process can improve mechanical properties and surface roughness of the coating. Supercritical electroplating process can refine grain to improve the surface roughness and hardness. However, so far there is no research combining the above two processes to explore its effect on the coating. This study aims to use ultrasound (42kHz) in supercritical CO2 (SC-CO2) electroplating process to investigate the effect of ultrasonic powers and supercritical pressures on the properties of copper films. From the results it was clear that higher ultrasonic irradiation resulted in higher current efficiency, grain refinement, higher hardness, better surface roughness and higher internal stress. SEM was also presented to verify the correctness of the measured data. The optimal parameters were set to obtain the deposit at pressure of 2000psi and ultrasonic irradiation of 0.157W/cm3. Compared with SC-CO2 electroplating process, the current efficiency can be increased from 77.57% to 93.4%, the grain size decreases from 24.34nm to 22.45nm, the hardness increases from 92.87Hv to 174.18Hv, and the surface roughness decreases from 0.83μm to 0.28μm. Therefore, this study has successfully integrated advantages of ultrasound and SC-CO2 electroplating, and proved that applied ultrasound to SC-CO2 electroplating process can significantly improve the mechanical properties of the coating.

Effects of ultrasonic agitation and surfactant additive on surface roughness of Si (1 1 1) crystal plane in alkaline KOH solution

In the silicon wet etching process, the “pseudo-mask” formed by the hydrogen bubbles generated during the etching process is the reason causing high surface roughness and poor surface quality. Based upon the ultrasonic mechanical effect and wettability enhanced by isopropyl alcohol (IPA), ultrasonic agitation and IPA were used to improve surface quality of Si (111) crystal plane during silicon wet etching process. The surface roughness Rq is smaller than 15nm when using ultrasonic agitation and Rq is smaller than 7nm when using IPA. When the range of IPA concentration (mass fraction, wt%) is 5–20%, the ultrasonic frequency is 100kHz and the ultrasound intensity is 30–50W/L, the surface roughness Rq is smaller than 2nm when combining ultrasonic agitation and IPA. The surface roughness Rq is equal to 1nm when the mass fraction of IPA, ultrasound intensity and the ultrasonic frequency is 20%, 50W and 100kHz respectively. The experimental results indicated that the combination of ultrasonic agitation and IPA could obtain a lower surface roughness of Si (111) crystal plane in silicon wet etching process.

Analysis of the effect of ultrasonic agitation on the cleaning of root canals using different periods during the final irrigation

The ultrasonic agitation was introduced as an adjuvant to conventional chemo-mechanical debridement during endodontic treatment to overcome the persistence of biofilms. Objective: To verify the cleaning of root canals irrigated with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), with or without an ultrasonic agitation, using different time periods and images obtained by scanning electron microscope (SEM). Material and methods: Forty mandibular incisors were cleaned, shaped and randomly divided into five groups according to the final irrigation protocol: SH10 group (ultrasonic agitation with NaOCl for 10 s), SH30 group (ultrasonic agitation with NaOCl for 30 s), SHE30 group (ultrasonic agitation with NaOCl and EDTA for 10 s), SHE90 group (ultrasonic agitation with NaOCl and EDTA for 30 s), and control group (NaOCl and EDTA without ultrasonic agitation). The teeth were prepared and analyzed by SEM at ×2000. The Kruskal–Wallis test was used with a 5% level of significance. Results: For the cervical and medial thirds, there was no statistically significant difference in cleaning among the protocols used (p &gt; 0.05). For the cleaning of the apical third, SHE90 group demonstrated a significant difference (p &lt; 0.05), as compared to the control and SH10 groups. Conclusion: For the final irrigation, an ultrasonic agitation with NaOCl and EDTA for 30 s allowed a better cleaning of the debris in the apical third of the root canal.

Effects of Ultrasonic Agitation on the Structural and Magnetic Properties of CoFe2O4 Nanocrystals

AbstractCobalt ferrite nanocrystals (CoFe2O4) were synthesized by means of ultrasonic agitation and afterward subjected to different annealing temperatures. The structural and morphological properties of the nanocrystals were investigated by means of X‐ray diffraction and scanning electron microscopy. The results showed that the samples were composed of CoFe2O4 monophase nanocrystals. The particle size increased with increasing annealing temperatures. Infrared spectroscopy and magnetization showed that the samples exhibited the usual features of CoFe2O4 nanocrystals. Superparamagnetism was not observed at room temperature. However, the results indicated that the samples could be considered single‐domain particles with blocking temperatures greater than 300 K. Both infrared and magnetic results indicated possible diffusion of cobalt ions from tetrahedral to octahedral sites as a function of the annealing temperature.

Effect of Various Mixing and Placement Techniques on the Flexural Strength and Porosity of Mineral Trioxide Aggregate

IntroductionThe aim of this study was to evaluate the effect of mechanical and manual mixing as well as the effect of ultrasonic agitation during placement on the flexural strength and porosity of mineral trioxide aggregate (MTA). MethodsWhite ProRoot MTA and white MTA Angelus were used. One gram of each powder was mixed with a 0.34-g aliquot of distilled water. Specimens were mixed either by mechanical mixing of capsules for 30 seconds at 4500 rpm or by a saturation technique and application of a condensation pressure of 3.22 MPa for 1 minute. The mixed slurries of all materials were loaded into 2 × 2 × 25 mm molds for testing flexural strength and 3 × 4 mm molds for evaluation of porosity. Half of the specimens were placed in the stainless steel molds by using indirect ultrasonic activation. All specimens were incubated for 4 days. Micro–computed tomography was used to determine the porosity of each specimen, and a 3-point bending test was used to evaluate flexural strength. Tukey honestly significant difference and independent t tests were carried out to compare the means at a significance level of P < .05. ResultsIrrespective of mixing and placement techniques applied, the flexural strength values of ProRoot MTA were significantly greater than those of MTA Angelus (P < .05). A medium negative correlation was found between flexural strength values and total porosity percentage. ConclusionsAlthough mechanical mixing of encapsulated cements was quicker and provided more consistent mixes, this technique along with ultrasonic agitation was not associated with a significant advantage in terms of flexural strength and total porosity over manual mixing.

The Effect of Various Mixing and Placement Techniques on the Compressive Strength of Mineral Trioxide Aggregate

IntroductionThe aim of this study was to evaluate the effect of various mixing techniques including mechanical and manual mixing as well as the effect of ultrasonic agitation during placement on the compressive strength of mineral trioxide aggregate (MTA). MethodsTooth-colored ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and white MTA Angelus (Angelus Soluções Odontologicas, Londrina, Brazil) were used. One gram of each powder was mixed with a 0.34-g aliquot of distilled water. Specimens were mixed either by mechanical mixing of capsules for 30 seconds at 4,500 rpm or by a saturation technique and the application of a condensation pressure of 3.22 MPa for 1 minute. Half of the specimens were placed in stainless steel molds and agitated using indirect ultrasonic activation. All specimens were subjected to compressive strength testing after 4 days. ResultsThe compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus (P < .05). The highest compressive strength values were recorded from ProRoot MTA samples that were mixed mechanically and placed using ultrasonic activation (mean = 101.71 MPa), whereas the lowest values were recorded for MTA Angelus samples that were mixed manually and placed without ultrasonic activation (mean = 53.47 MPa). Ultrasonically agitated groups had higher compressive strength values (P < .001). The specimens mixed mechanically had higher compressive strength values than those mixed manually (P < .05). ConclusionsThe compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus. Mechanical mixing enhanced the compressive strength of the material. Regardless of the mixing techniques applied, ultrasonic agitation improved the compressive strength of the material.

Effect of Ultrasonic on Grain Density of Electroplated Diamond Tools

Coating quality and electroplating efficiency can be improved by application of ultrasonic agitation. The nickel coatings and electroplated diamond tools were fabricated. The effects of ultrasonic agitation on tool fabrication processes were analyzed. Cathode polarization curves and coating hardness were measured. Diamond grains on tool substrate were observed with microscope. Alumina grinding experiments were carried out and grinding ratios were calculated. Experimental results show that cathode polarization degree reduced during ultrasonic electroplating processes. Before diamond grain tack-on operation, ultrasonic agitation can make grain dense and guarantee nice contact between substrate and grains. High grain density of diamond tool can be obtained in tack-on operation after above ultrasonic agitation operation. Ultrasonic agitation is not suitable for the tack-on operation of diamond grains. During buildup processes, some buildup time is needed to obtain enough thickness of nickel coating before ultrasonic agitation is applied. The diamond tools fabricated with ultrasonic agitation present better cutting ability. During tool fabricating processes, the reasonable application of ultrasonic agitation is necessary.

The effect of ultrasonic agitation on the stripping of photoresist using supercritical CO 2 and co-solvent formulation

A novel technology for removing high-dose ion-implanted photoresist (HDI PR) from semiconductor wafers using supercritical carbon dioxide (scCO 2) and several co-solvent formulations have been described. A combination of ultrasonic agitation with scCO 2/co-solvent stripping was found to be an effective method for photoresist removal. Ultrasonic agitation was an efficient technique for achieving higher stripping rates. The effects of temperature, pressure, reaction time and the type of organic co-solvent on the stripping rate of HDI PR were investigated. The microstructures of sample wafers after stripping were characterized by scanning electron microscopy and energy dispersive X-ray spectrometer.

The effects of ultrasonic agitation in laundering on the properties of wool fabrics

This paper investigates the use of ultrasonic agitation as a method for reducing felting and area shrinkage during the laundering of wool fabric. Work was conducted to evaluate the changes in fibre and fabric properties after repeated exposure to ultrasonic agitation, and also the effectiveness of ultrasonic treatment to remove common stains. Fabric colour, appearance, tensile strength, dimensional stability and thickness were measured before and after each test. Ultrasonic agitation produced fine cracks in the scale structure of the fibre, but these had negligible effects on the strength and colour when compared to hand washing. Ultrasonic agitation caused less fibre migration than hand washing, with a reduced rate of thickness increase and felting. Ultrasonic agitation increased the level of stain removed from the fabric when compared with hand washing.