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Fulltext Non-intrusive capacitance tomography for on-line visualization gas-liquid flow in horizontal pipe

Mustapha, I., Takriff, M.S., Kamaruddin, S.K., Hassan, N.M., Zain, R.M.

Journal of Nuclear and Related Technologies, 2009;2009(2):41-48.
MyJurnal

Electrical capacitance tomography (ECT) velocimetry technique was utilized in this study to quantify the flow structure of gas-liquid based on the ECT images. A new 8 electrodes sensor ECT has been successfully developed to provide 2D images in a cross section of pipeline. The ECT has been attentively applied in the test section of the flow rig for imaging the gas-liquid distribution. The inside diameter of ECT pipeline sensor is 100mm. Meanwhile, the flow rig consists of close loop of “CPVC” pipes that includes a pipe test section, two tanks of oil and water respectively and allows the working pressure up to 5 bars. Transparent pipe is used for visual monitoring. A portable Doppler flow meter that utilizes the ultrasonic signal has also been placed at the test section to measure the velocity. The images obtained by ECT show that the different flow patterns have been observed in the horizontal pipe during the experiment. The technique enables realization of the time and position at which particle density fluctuations with respect to dominant time-space levels pass through the pipeline.

Matched MeSH terms: Ultrasonics
Fulltext Development of catalytic converter by washcoat of γ-alumina on nickel oxide (Nio) catalyst in FeCrAl substrate for exhaust emission control : proposed study

Leman, A.M., Fatin Afiqah Jajuli, Dafit Feriyanto

Journal of Occupational Safety and Health, 2015;12(2):65-70.
MyJurnal

Automobile exhaust emission control is one of the trending issues in automobile research field. It caused by high
pollution such as carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) distributed by automobile
especially form diesel engine. These pollutants give a harmful effect to the environment and human health. Therefore,
this paper proposed in reviewing methods on fabrication of modified catalytic converter. FeCrAl is used as substrate
which treated using ultrasonic bath technique which could improve the exhaust emission control. This metallic catalytic converter used as the replacement of precious metal that have high production cost.

Matched MeSH terms: Ultrasonics
Fulltext Using a syringe needle to cut dentin and dislodge and remove a metallic obstruction from the root canal

Vivekananda Pai AR, Arora V

J Conserv Dent, 2018 4 21;21(2):230-232.
PMID: 29674831 DOI: 10.4103/JCD.JCD_316_16

A metallic obstruction in the canal orifice of a maxillary right canine could not be bypassed during endodontic treatment. Aids such as ultrasonics and retrieval kits were not available for the removal of the obstruction. Therefore, a novel approach using a disposable syringe needle was employed. A 22-gauge needle was inserted into the orifice and turned in an arc with a gentle apical pressure and alternate rocking motion around the obstruction. This procedure was repeated few times to cut dentin and successfully dislodge and remove the obstruction using the sharp beveled tip of the needle. This case report demonstrates that, in the absence of other aids, the use of a disposable syringe needle is a simple, economical, and yet an effective technique for conservative removal of dentin and to dislodge and remove an obstruction from the root canal. However, its effectiveness depends on case selection and straight-line accessibility to the obstruction.

Matched MeSH terms: Ultrasonics
Low temperature followed by matrix solid-phase dispersion-sonication procedure for the determination of multiclass pesticides in palm oil using LC-TOF-MS

Sobhanzadeh E, Abu Bakar NK, Bin Abas MR, Nemati K

J Hazard Mater, 2011 Feb 28;186(2-3):1308-13.
PMID: 21177032 DOI: 10.1016/j.jhazmat.2010.12.001

A simple and effective multiresidue method based on precipitation at low temperature followed by matrix solid-phase dispersion-sonication was developed and validated to determine dimethoate, malathion, carbaryl, simazine, terbuthylazine, atrazine and diuron in palm oil using liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS). Liquid-liquid extraction (LLE) followed by low temperature method were optimized by studying the effect of type and volume of organic solvent (acetonitrile, acetonitrile:n-hexane (3:2 v/v) and acetone) and time of freezing to obtain high recovery yield and low co-extract fat residue in the final extract. The optimal conditions for matrix solid-phase dispersion (MSPD) were obtained using 5 g of palm oil, 2 g of primary secondary amine (PSA) as dispersing sorbent, 1 g of graphitized carbon black (GCB) as clean-up sorbent and 15 mL of acetonitrile as eluting solvent under conditions of 15 min ultrasonication at room temperature. Method validation was performed in order to study sensitivity, linearity, precision, and accuracy. Average recoveries at three concentration levels (25, 50 and 100 μg kg(-1)) were found in the range of 72.6-91.3% with relative standard deviations between 5.3% and 14.2%. Detection and quantification limits ranged from 1.5 to 5 μg kg(-1) and from 2.5 to 9 μg kg(-1), respectively.

Matched MeSH terms: Ultrasonics
Heat treatment effects on the characteristics and sonocatalytic performance of TiO2 in the degradation of organic dyes in aqueous solution

Abdullah AZ, Ling PY

J Hazard Mater, 2010 Jan 15;173(1-3):159-67.
PMID: 19740600 DOI: 10.1016/j.jhazmat.2009.08.060

The ambient sonocatalytic degradation of congo red, methyl orange, and methylene blue by titanium dioxide (TiO(2)) catalyst at initial concentrations between 10 and 50mg/L, catalyst loadings between 1.0 and 3.0mg/L and hydrogen peroxide (H(2)O(2)) concentrations up to 600 mg/L is reported. A 20 kHz ultrasonic processor at 50 W was used to accelerate the reaction. The catalysts were exposed to heat treatments between 400 and 1000 degrees C for up to 4h to induce phase change. Sonocatalysts with small amount of rutile phase showed better sonocatalytic activity but excessive rutile phase should be avoided. TiO(2) heated to 800 degrees C for 2h showed the highest sonocatalytic activity and the degradation of dyes was influenced by their chemical structures, chemical phases and characteristics of the catalysts. Congo red exhibited the highest degradation rate, attributed to multiple labile azo bonds to cause highest reactivity with the free radicals generated. An initial concentration of 10mg/L, 1.5 g/L of catalyst loading and 450 ppm of H(2)O(2) gave the best congo red removal efficiency of above 80% in 180 min. Rate coefficients for the sonocatalytic process was successfully established and the reused catalyst showed an activity drop by merely 10%.

Matched MeSH terms: Ultrasonics*
In-vitro evaluation of microleakage of bioceramic root-end filling materials: A spectrophotometric study

Gupta R, Kewalramani R

J Oral Biol Craniofac Res, 2021 03 10;11(2):330-333.
PMID: 33786296 DOI: 10.1016/j.jobcr.2021.03.001

Aim: To evaluate the microleakage of newer bioceramic root-end filling materials.
Material and method: Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 mm. All teeth were stored in 2% methylene blue for 72 h followed by emersion in 65% nitric acid for the next 72 h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer.
Result: Microleakage was found to be increasing in this order: Biodentin 0.01).
Conclusion: All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.

Matched MeSH terms: Ultrasonics
Ultrasonic-assisted glycosylation with κ-carrageenan on the functional and structural properties of fish gelatin

Ding K, Geng H, Guo W, Sun W, Zhan S, Lou Q, et al.

J Sci Food Agric, 2023 Aug 30;103(11):5322-5331.
PMID: 37016806 DOI: 10.1002/jsfa.12600

BACKGROUND: Fish gelatin (FG) has multifunctional properties similar to mammalian gelatin (MG), and it has been recognized as the optimal alternative to MG. While its poor surface-active and gelling properties significantly limit its application values, glycosylation has been successfully used to increase surface-active properties of FG, but the influence of ultrasonic-associated glycosylation (UAG) on the gelling and structural characteristics of FG is still rarely reported. This article explores UAG (100-200 W, 0.5-1 h) with κ-carrageenan (κC) on the functional properties (emulsifying, gelling and rheological properties) and structural characteristics of FG.
RESULTS: The longer time and higher power of ultrasonics accelerated the glycosylation reaction with an increase in glycosylation degree and browning index values. Compared with original FG, FG-κC mixture and bovine gelatin, UAG-modified FG possessed higher emulsification activity index, emulsion stability index, gel strength, hardness and melting temperature values. Among them, gelatin modified by appropriate ultrasonic conditions (200 W, 0.5 h) had the highest emulsifying and gelling properties. Rheological results showed that UAG contributed to the gelation process of gelatin with advanced gelation time and endowed it with high viscosity. Structural analysis indicated that UAG promoted κC to link with FG by the formation of covalent and hydrogen bonds, restricting more bound and immobilized water in the gels, exhibiting higher gelling properties.
CONCLUSION: This work showed that UAG with κC is a promising method to produce high gelling and emulsifying properties of FG that could replace MG. © 2023 Society of Chemical Industry.

Matched MeSH terms: Ultrasonics*
Fulltext Effect of deposition time on electrophoretic deposition of carbon nanotubes on carbon fabric

Noor Erna Fatini Mohd, Mariatti Jaafar, Tuti Katrina Abdullah

Malaysian Journal of Microscopy, 2016;12(1):54-62.
MyJurnal

Carbon fiber reinforced epoxy (CFRE) is commonly been used in automotive and aviation industries. However, CFRE composite exhibits the problem of adherence between fiber and matrix. The interface between carbon fiber (CF) and epoxy becomes a weak zone and leads to the debonding defect of fiber and low mechanical properties of composites. The main focus of this study is to fabricate CFRE using carbon nanotubes (CNTs), as the hybrid reinforcement with CF. Ultrasonic method is used to disperse CNTs in distilled water for 20 minutes, followed by deposition of CNTs on CF using electrophoretic deposition (EPD) technique. Hand lay-up assisted vacuum bagging is employed to fabricate CNTs/CF/Epoxy composite. From morphologies, surface topography and peel off testing, it can be confirmed that 30 minutes deposition allowed more CNTs to deposit on CF. The flexural properties shows that 30 minutes deposition inherited high flexural strength, 67.4 MPa and modulus, 8490 MPa.

Matched MeSH terms: Ultrasonics
Predicting the outcome of pregnancy in threatened abortion using ultrasound in detecting the viability of foetus

Gabriel R

Malays J Reprod Health, 1992 Jun;10(1):19-22.
PMID: 12345025

PIP: Between December 1990 and May 1991 in Malaysia, clinicians at the Sultanah Aminah Hospital in Johor Bahru screened 200 women with a diagnosis of threatened miscarriage with ultrasound to determine whether ultrasound could evaluate the viability of the fetus and thus the outcome of pregnancy in cases of threatened abortion. A fetal heartbeat was absent in 65% of cases with the remaining 35% of cases having a fetal heartbeat. Nonviability of the fetus or an abnormal or very early pregnancy may have accounted for an absent fetal heartbeat. The pregnancy of 46% of cases continued while 41% experienced spontaneous abortion. Just 6.2% of cases with a fetal heartbeat suffered from spontaneous abortion compared with 69.7% of those without a fetal heartbeat. 93.8% of cases with a fetal heartbeat continued their pregnancies compared with 30.3% of those without a fetal heartbeat. Inability of ultrasound to detect fetal heartbeats during early pregnancy probably accounted for the somewhat high percentage of those without a fetal heartbeat who continued their pregnancies. Among patients with a fetal heartbeat, the number of pregnancies that continued. Ultrasound detected 13% abnormal pregnancies (i.e., molar pregnancy or ectopic pregnancy). Surgery on these cases confirmed the ultrasound findings. These results showed that ultrasound should be used in every case of threatened miscarriage and that a fetal heartbeat does indicate the viability of the fetus.

Matched MeSH terms: Ultrasonics*
Fulltext Performance of Epoxy Resin Polymer as Self-Healing Cementitious Materials Agent in Mortar

Huseien GF, Sam ARM, Faridmehr I, Baghban MH

Materials (Basel), 2021 Mar 06;14(5).
PMID: 33800835 DOI: 10.3390/ma14051255

This research investigated the application of epoxy resin polymer as a self-healing strategy for improving the mechanical and durability properties of cement-based mortar. The epoxy resin was added to the concrete mix at various levels (5, 10, 15, and 20% of cement weight), and the effectiveness of healing was evaluated by microstructural analysis, compressive strength, and non-destructive (ultrasonic pulse velocity) tests. Dry and wet-dry conditions were considered for curing, and for generating artificial cracks, specimens at different curing ages (1 and 6 months) were subjected to compressive testing (50 and 80% of specimen's ultimate compressive strength). The results indicated that the mechanical properties in the specimen prepared by 10% epoxy resin and cured under wet-dry conditions was higher compared to other specimens. The degree of damage and healing efficiency index of this particular mix design were significantly affected by the healing duration and cracking age. An optimized artificial neural network (ANN) combined with a firefly algorithm was developed to estimate these indexes over the self-healing process. Overall, it was concluded that the epoxy resin polymer has high potential as a mechanical properties self-healing agent in cement-based mortar.

Matched MeSH terms: Ultrasonics
Fulltext Performance Evaluation of Modified Rubberized Concrete Exposed to Aggressive Environments

M Mhaya A, Baghban MH, Faridmehr I, Huseien GF, Abidin ARZ, Ismail M

Materials (Basel), 2021 Apr 11;14(8).
PMID: 33920340 DOI: 10.3390/ma14081900

Recycling of the waste rubber tire crumbs (WRTCs) for the concretes production generated renewed interest worldwide. The insertion of such waste as a substitute for the natural aggregates in the concretes is an emergent trend for sustainable development towards building materials. Meanwhile, the enhanced resistance of the concrete structures against aggressive environments is important for durability, cost-saving, and sustainability. In this view, this research evaluated the performance of several modified rubberized concretes by exposing them to aggressive environments i.e., acid, and sulphate attacks, elevated temperatures. These concrete (12 batches) were made by replacing the cement and natural aggregate with an appropriate amount of the granulated blast furnace slag (GBFS) and WRTCs, respectively. The proposed mix designs' performance was evaluated by several measures, including the residual compressive strength (CS), weight loss, ultrasonic pulse velocity (UPV), microstructures, etc. Besides, by using the available experimental test database, an optimized artificial neural network (ANN) combined with the particle swarm optimization (PSO) was developed to estimate the residual CS of modified rubberized concrete after immersion one year in MgSO4 and H2SO4 solutions. The results indicated that modified rubberized concrete prepared by 5 to 20% WRTCs as a substitute to natural aggregate, provided lower CS and weight lose expose to sulphate and acid attacks compared to control specimen prepared by ordinary Portland cement (OPC). Although the CS were slightly declined at the elevated temperature, these proposed mix designs have a high potential for a wide variety of concrete industrial applications, especially in acid and sulphate risk.

Matched MeSH terms: Ultrasonics
Fulltext Performance of Fly Ash Geopolymer Concrete Incorporating Bamboo Ash at Elevated Temperature

Ishak S, Lee HS, Singh JK, Ariffin MAM, Lim NHAS, Yang HM

Materials (Basel), 2019 Oct 17;12(20).
PMID: 31627479 DOI: 10.3390/ma12203404

This paper presents the experimental results on the behavior of fly ash geopolymer concrete incorporating bamboo ash on the desired temperature (200 °C to 800 °C). Different amounts of bamboo ash were investigated and fly ash geopolymer concrete was considered as the control sample. The geopolymer was synthesized with sodium hydroxide and sodium silicate solutions. Ultrasonic pulse velocity, weight loss, and residual compressive strength were determined, and all samples were tested with two different cooling approaches i.e., an air-cooling (AC) and water-cooling (WC) regime. Results from these tests show that with the addition of 5% bamboo ash in fly ash, geopolymer exhibited a 5 MPa (53%) and 5.65 MPa (66%) improvement in residual strength, as well as 940 m/s (76%) and 727 m/s (53%) greater ultrasonic pulse velocity in AC and WC, respectively, at 800 °C when compared with control samples. Thus, bamboo ash can be one of the alternatives to geopolymer concrete when it faces exposure to high temperatures.

Matched MeSH terms: Ultrasonics
Fulltext Properties of Foamed Mortar Prepared with Granulated Blast-Furnace Slag

Zhao X, Lim SK, Tan CS, Li B, Ling TC, Huang R, et al.

Materials (Basel), 2015 Jan 30;8(2):462-473.
PMID: 28787950 DOI: 10.3390/ma8020462

Foamed mortar with a density of 1300 kg/m³ was prepared. In the initial laboratory trials, water-to-cement (w/c) ratios ranging from 0.54 to 0.64 were tested to determine the optimal value for foamed mortar corresponding to the highest compressive strength without compromising its fresh state properties. With the obtained optimal w/c ratio of 0.56, two types of foamed mortar were prepared, namely cement-foamed mortar (CFM) and slag-foamed mortar (SFM, 50% cement was replaced by slag weight). Four different curing conditions were adopted for both types of foamed mortar to assess their compressive strength, ultrasonic pulse velocity (UPV) and thermal insulation performance. The test results indicated that utilizing 50% of slag as cement replacement in the production of foamed mortar improved the compressive strength, UPV and thermal insulation properties. Additionally, the initial water curing of seven days gained higher compressive strength and increased UPV values as compared to the air cured and natural weather curing samples. However, this positive effect was more pronounced in the case of compressive strength than in the UPV and thermal conductivity of foamed mortar.

Matched MeSH terms: Ultrasonics
Antibacterial and cytotoxic effect of honey mediated copper nanoparticles synthesized using ultrasonic assistance

Ismail NA, Shameli K, Wong MM, Teow SY, Chew J, Sukri SNAM

Mater Sci Eng C Mater Biol Appl, 2019 Nov;104:109899.
PMID: 31499959 DOI: 10.1016/j.msec.2019.109899

In this study, a comparative study of effect using honey on copper nanoparticles (Cu-NPs) via simple, environmentally friendly process and inexpensive route was reported. Honey and ascorbic acid act as stabilizing and reducing agents with the assistance of sonochemical method. The products were characterized using UV-visible (UV-vis) spectroscopy, X-Ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Field-Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR) spectroscopy. The reddish brown colour demonstrated the formation of Cu-NPs and UV-visible proved the plasmon resonance of Cu-NPs. XRD also confirmed a highly pure Cu-NPs obtained with absence of copper oxide in which the structure is crystalline. The spherical size of the Cu-NPs was acquire in the presence of honey which is 3.68 ± 0.78 nm with narrow particle distribution. The antibacterial activity was seen against gram-positive and gram-negative bacteria which are Enterococcus faecalis (E. faecalis) and Escherichia coli (E. coli). At higher concentration of Cu-NPs, they were more effective in killing both bacteria. The Cu-NPs without and with honey exhibited toxicities toward normal and cancerous cells. However, Cu-NPs without honey showed more potent killing activity against normal and cancer cells.

Matched MeSH terms: Ultrasonics*
Feasibility of A-mode ultrasound attenuation as a monitoring method of local hyperthermia treatment

Manaf NA, Aziz MN, Ridzuan DS, Mohamad Salim MI, Wahab AA, Lai KW, et al.

Med Biol Eng Comput, 2016 Jun;54(6):967-81.
PMID: 27039402 DOI: 10.1007/s11517-016-1480-2

Recently, there is an increasing interest in the use of local hyperthermia treatment for a variety of clinical applications. The desired therapeutic outcome in local hyperthermia treatment is achieved by raising the local temperature to surpass the tissue coagulation threshold, resulting in tissue necrosis. In oncology, local hyperthermia is used as an effective way to destroy cancerous tissues and is said to have the potential to replace conventional treatment regime like surgery, chemotherapy or radiotherapy. However, the inability to closely monitor temperature elevations from hyperthermia treatment in real time with high accuracy continues to limit its clinical applicability. Local hyperthermia treatment requires real-time monitoring system to observe the progression of the destroyed tissue during and after the treatment. Ultrasound is one of the modalities that have great potential for local hyperthermia monitoring, as it is non-ionizing, convenient and has relatively simple signal processing requirement compared to magnetic resonance imaging and computed tomography. In a two-dimensional ultrasound imaging system, changes in tissue microstructure during local hyperthermia treatment are observed in terms of pixel value analysis extracted from the ultrasound image itself. Although 2D ultrasound has shown to be the most widely used system for monitoring hyperthermia in ultrasound imaging family, 1D ultrasound on the other hand could offer a real-time monitoring and the method enables quantitative measurement to be conducted faster and with simpler measurement instrument. Therefore, this paper proposes a new local hyperthermia monitoring method that is based on one-dimensional ultrasound. Specifically, the study investigates the effect of ultrasound attenuation in normal and pathological breast tissue when the temperature in tissue is varied between 37 and 65 °C during local hyperthermia treatment. Besides that, the total protein content measurement was also conducted to investigate the relationship between attenuation and tissue denaturation level at different temperature ranges. The tissues were grouped according to their histology results, namely normal tissue with large predominance of cells (NPC), cancer tissue with large predominance of cells (CPC) and cancer with high collagen fiber content (CHF). The result shows that the attenuation coefficient of ultrasound measured following the local hyperthermia treatment increases with the increment of collagen fiber content in tissue as the CHF attenuated ultrasound at the highest rate, followed by NPC and CPC. Additionally, the attenuation increment is more pronounced at the temperature over 55 °C. This describes that the ultrasound wave experienced more energy loss when it propagates through a heated tissue as the tissue structure changes due to protein coagulation effect. Additionally, a significant increase in the sensitivity of attenuation to protein denaturation is also observed with the highest sensitivity obtained in monitoring NPC. Overall, it is concluded that one-dimensional ultrasound can be used as a monitoring method of local hyperthermia since its attenuation is very sensitive to the changes in tissue microstructure during hyperthermia.

Matched MeSH terms: Ultrasonics*
An efficient data mining framework for the characterization of symptomatic and asymptomatic carotid plaque using bidimensional empirical mode decomposition technique

Molinari F, Raghavendra U, Gudigar A, Meiburger KM, Rajendra Acharya U

Med Biol Eng Comput, 2018 Sep;56(9):1579-1593.
PMID: 29473126 DOI: 10.1007/s11517-018-1792-5

Atherosclerosis is a type of cardiovascular disease which may cause stroke. It is due to the deposition of fatty plaque in the artery walls resulting in the reduction of elasticity gradually and hence restricting the blood flow to the heart. Hence, an early prediction of carotid plaque deposition is important, as it can save lives. This paper proposes a novel data mining framework for the assessment of atherosclerosis in its early stage using ultrasound images. In this work, we are using 1353 symptomatic and 420 asymptomatic carotid plaque ultrasound images. Our proposed method classifies the symptomatic and asymptomatic carotid plaques using bidimensional empirical mode decomposition (BEMD) and entropy features. The unbalanced data samples are compensated using adaptive synthetic sampling (ADASYN), and the developed method yielded a promising accuracy of 91.43%, sensitivity of 97.26%, and specificity of 83.22% using fourteen features. Hence, the proposed method can be used as an assisting tool during the regular screening of carotid arteries in hospitals. Graphical abstract Outline for our efficient data mining framework for the characterization of symptomatic and asymptomatic carotid plaques.

Matched MeSH terms: Ultrasonics
Fulltext Compact Elliptical UWB Antenna for Underwater Wireless Communications

Alhawari ARH, Majeed SF, Saeidi T, Mumtaz S, Alghamdi H, Hindi AT, et al.

Micromachines (Basel), 2021 Apr 07;12(4).
PMID: 33917167 DOI: 10.3390/mi12040411

The increasing needs of free licensed frequency bands like Industrial, Scientific, and Medical (ISM), Wireless Local Area Network (WLAN), and 5G for underwater communications required more bandwidth (BW) with higher data transferring rate. Microwaves produce a higher transferring rate of data, and their associated devices are smaller in comparison with sonar and ultrasonic. Thus, transceivers should have broad BW to cover more of a frequency band, especially from ultra-wideband (UWB) systems, which show potential outcomes. However, previous designs of similar work for underwater communications were very complicated, uneasy to fabricate, and large. Therefore, to overcome these shortcomings, a novel compact elliptical UWB antenna is designed to resonate from 1.3 to 7.2 GHz. It is invented from a polytetrafluoroethylene (PTFE) layer with a dielectric constant of 2.55 mm and a thickness of 0.8 mm. The proposed antenna shows higher gain and radiation efficiency and stability throughout the working band when compared to recent similarly reported designs, even at a smaller size. The characteristics of the functioning antenna are investigated through fluid mediums of fresh-water, seawater, distilled water, and Debye model water. Later, its channel capacity, bit rate error, and data rate are evaluated. The results demonstrated that the antenna offers compact, easier fabrication with better UWB characteristics for underwater 5G communications.

Matched MeSH terms: Ultrasonics
Fulltext Optimization of Ultrasound-Assisted Extraction Conditions Followed by Solid Phase Extraction Fractionation from Orthosiphon stamineus Benth (Lamiace) Leaves for Antiproliferative Effect on Prostate Cancer Cells

Suhaimi SH, Hasham R, Hafiz Idris MK, Ismail HF, Mohd Ariffin NH, Abdul Majid FA

Molecules, 2019 Nov 18;24(22).
PMID: 31752230 DOI: 10.3390/molecules24224183

Primarily, optimization of ultrasonic-assisted extraction (UAE) conditions of Orthospihon stamineus was evaluated and verified using a central composite design (CCD) based on three factors including extraction time (minutes), ultrasound amplitude (A), and solvent concentration (%). The response surface methodology (RSM) was performed to develop an extraction method with maximum yield and high rosmarinic acid content. The optimal UAE conditions were as follows: extraction time 21 min, ultrasound amplitudes 62 A, and solvent composition 70% ethanol in water. The crude extract was further fractionated using solid-phase extraction (SPE), where six sequential fractions that varied in polarity (0-100% Acetonitrile in water) were obtained. Next, the six fractions were evaluated for their antioxidant and anti-cancer properties. This study found that Fraction 2 (F2) contained the highest rosmarinic acid content and showed the strongest antioxidant activity. Additionally, F2 showed an anti-proliferative effect against prostate cancer (DU145) with no harmful effect on normal cells.

Matched MeSH terms: Ultrasonics
Ultrasonic extraction of anthocyanin from Clitoria ternatea flowers using response surface methodology

Chong FC, Gwee XF

Nat Prod Res, 2015;29(15):1485-7.
PMID: 25836369 DOI: 10.1080/14786419.2015.1027892

The ultrasonic extraction (UE) method of anthocyanin from Clitoria ternatea flowers using response surface methodology (RSM) was performed in this study. By using RSM, the objective is to optimise the extraction yield of anthocyanin from C. ternatea which is influenced by various factors, including the extraction temperature, time, ratio of solvent to solid and ultrasonic power. The empirical model was investigated by performing first-level optimisation in a two-level factorial design with Design Expert 7 software. In comparison with the conventional solvent extraction, UE showed a 246.48% better extraction yield and produced an anthocyanin extract with a radical scavenging activity of 68.48% at the optimised factors of 50°C, 150 min, 15 mL/g and 240 W.

Matched MeSH terms: Ultrasonics/methods*
GC-MS analysis of metabolites from soxhlet extraction, ultrasound-assisted extraction and supercritical fluid extraction of Salacca zalacca flesh and its alpha-glucosidase inhibitory activity

Saleh MSM, Bukhari DAM, Siddiqui MJA, Kasmuri AR, Murugesu S, Khatib A

Nat Prod Res, 2020 May;34(9):1341-1344.
PMID: 30678487 DOI: 10.1080/14786419.2018.1560295

Different extraction processes were employed to extract bioactive metabolites from Salacca zalacca flesh by a range of aqueous and organic solvents. The highest extraction yield was obtained by 50% ethanol extract of SE (73.18 ± 4.35%), whereas SFE_1 showed the lowest yield (0.42 ± 0.08%). All extracts were evaluated for in vitro α-glucosidase inhibitory activity, measured by their IC50 values in comparison to that of quercetin, the positive control (IC50 = 2.7 ± 0.7 μg/mL). The lowest α-glucosidase inhibitory activity was indicated by water extract of SE (IC50 = 724.3 ± 42.9 μg/mL) and the highest activity was demonstrated by 60% ethanol extract by UAE (IC50 = 16.2 ± 2.4 μg/mL). All extracts were analysed by GC-MS and identified metabolites like carbohydrates, fatty acids, organic acids, phenolic acids, sterols and alkane-based compounds etcetera that may possess the potential as α-glucosidase inhibitor and may attribute to the α-glucosidase inhibitory activity.

Matched MeSH terms: Ultrasonics

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