Search results for: ultrasound disintegration
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 535

Search results for: ultrasound disintegration

235 Comparison of Different Extraction Methods for the Determination of Polyphenols

Authors: Senem Suna

Abstract:

Extraction of bioactive compounds from several food/food products comes as an important topic and new trend related with health promoting effects. As a result of the increasing interest in natural foods, different methods are used for the acquisition of these components especially polyphenols. However, special attention has to be paid to the selection of proper techniques or several processing technologies (supercritical fluid extraction, microwave-assisted extraction, ultrasound-assisted extraction, powdered extracts production) for each kind of food to get maximum benefit as well as the obtainment of phenolic compounds. In order to meet consumer’s demand for healthy food and the management of quality and safety requirements, advanced research and development are needed. In this review, advantages, and disadvantages of different extraction methods, their opportunities to be used in food industry and the effects of polyphenols are mentioned in details. Consequently, with the evaluation of the results of several studies, the selection of the most suitable food specific method was aimed.

Keywords: bioactives, extraction, powdered extracts, supercritical fluid extraction

Procedia PDF Downloads 205
234 Evaluation of Pretreatment and Bioactive Compounds Recovery from Chlorella vulgaris

Authors: Marina Stramarkou, Sofia Papadaki, Konstantina Kyriakopoulou, Magdalini Krokida

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Nowadays, microalgae represent the diverse branch of microorganism that is used not only in fish farming, but also in food, cosmetics, pharmaceuticals and biofuel production as they can produce a wide range of unique functional ingredients. In the present work, a remarkable microalga Chlorella vulgaris (CV) was selected as a raw material for the recovery of multifunctional extracts. First of all, the drying of raw biomass was examined with freeze-drying showing the best behavior. Ultrasonic-assisted extraction (UAE) using different solvents was applied under the specific optimized conditions. In case of raw biomass, ethanol was the suitable solvent, whereas on dried samples water performed better. The total carotenoid, β-carotene, chlorophyll and protein content in the raw materials, extracts and extraction residues was determined using UV-Vis spectrometry. The microalgae biomass and the extracts were evaluated regarding their antiradical activity using the DPPH method.

Keywords: antioxidant activity, pigments, proteins, ultrasound assisted extraction

Procedia PDF Downloads 292
233 Study of Anti-Symmetric Flexural Mode Propagation along Wedge Tip with a Crack

Authors: Manikanta Prasad Banda, Che Hua Yang

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Anti-symmetric wave propagation along the particle motion of the wedge waves is known as anti-symmetric flexural (ASF) modes which travel along the wedge tips of the mid-plane apex with a small truncation. This paper investigates the characteristics of the ASF modes propagation with the wedge tip crack. The simulation and experimental results obtained by a three-dimensional (3-D) finite element model explained the contact acoustic non-linear (CAN) behavior in explicit dynamics in ABAQUS and the ultrasonic non-destructive testing (NDT) method is used for defect detection. The effect of various parameters on its high and low-level conversion modes are known for complex reflections and transmissions involved with direct reflections and transmissions. The results are used to predict the location of crack through complex transmission and reflection coefficients.

Keywords: ASF mode, crack detection, finite elements method, laser ultrasound technique, wedge waves

Procedia PDF Downloads 95
232 Effects of Pretreated Rice Bran on Wheat Dough Performance and Barbari Bread Quality

Authors: E. Ataye-Salehi, P. Taghinia, Z. Sheikholeslami

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In this research, roasted and sonicated rice bran were added at 0, 5%, 10%, and 15% (w/w) in wheat flour for the production of Barbari bread (semi-voluminous Iranian bread). Dough's rheological properties and textural and sensory characteristics of bread were investigated. The results showed that water absorption, development time and the degree of dough softening were increased, but dough stability was decreased by adding pretreated rice bran. Adding pretreated rice bran was increased, the moisture content and L* value of bread crust. The texture of samples which contained 10% pretreated rice bran during 3 hours after baking was less stiff than of control. But 48 hours after baking there was no significant difference between samples which contained 5%, 10% of rice bran and the sample without rice bran. Finally, the samples with 10% rice bran were selected as the best productive samples in this research by panelists.

Keywords: Barbari bread, rice bran, roasting, ultrasound

Procedia PDF Downloads 245
231 Impact of Pretreated Rice Bran on Wheat Dough Performance and Barbari Bread Quality

Authors: P. Taghinia, E. Ataye-Salehi, Z. Sheikholeslami

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In this research, roasted and sonicated rice bran were added at 0, 5%, 10%, and 15% (w/w) in wheat flour for the production of Barbari breead (semi-voluminous Iranian bread). Dough's rheological properties and textural and sensory characteristics of bread were investigated. The results showed that water absorption, development time and the degree of dough softening were increased but dough stability was decreased by adding pretreated rice bran. Adding pretreated rice bran was increased, the moisture content and L* value of bread crust. The texture of samples which contained 10% pretreated rice bran during 3 hours after baking was less stiff than of control, but 48 hours after baking there was no significant difference between samples which contained 5%, 10% of rice bran and the sample without rice bran. Finally, the samples with 10% rice bran were selected as the best productive samples in this research by panelists.

Keywords: Barbari bread, rice bran, roasting, ultrasound

Procedia PDF Downloads 361
230 The Brain’s Attenuation Coefficient as a Potential Estimator of Temperature Elevation during Intracranial High Intensity Focused Ultrasound Procedures

Authors: Daniel Dahis, Haim Azhari

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Noninvasive image-guided intracranial treatments using high intensity focused ultrasound (HIFU) are on the course of translation into clinical applications. They include, among others, tumor ablation, hyperthermia, and blood-brain-barrier (BBB) penetration. Since many of these procedures are associated with local temperature elevation, thermal monitoring is essential. MRI constitutes an imaging method with high spatial resolution and thermal mapping capacity. It is the currently leading modality for temperature guidance, commonly under the name MRgHIFU (magnetic-resonance guided HIFU). Nevertheless, MRI is a very expensive non-portable modality which jeopardizes its accessibility. Ultrasonic thermal monitoring, on the other hand, could provide a modular, cost-effective alternative with higher temporal resolution and accessibility. In order to assess the feasibility of ultrasonic brain thermal monitoring, this study investigated the usage of brain tissue attenuation coefficient (AC) temporal changes as potential estimators of thermal changes. Newton's law of cooling describes a temporal exponential decay behavior for the temperature of a heated object immersed in a relatively cold surrounding. Similarly, in the case of cerebral HIFU treatments, the temperature in the region of interest, i.e., focal zone, is suggested to follow the same law. Thus, it was hypothesized that the AC of the irradiated tissue may follow a temporal exponential behavior during cool down regime. Three ex-vivo bovine brain tissue specimens were inserted into plastic containers along with four thermocouple probes in each sample. The containers were placed inside a specially built ultrasonic tomograph and scanned at room temperature. The corresponding pixel-averaged AC was acquired for each specimen and used as a reference. Subsequently, the containers were placed in a beaker containing hot water and gradually heated to about 45ᵒC. They were then repeatedly rescanned during cool down using ultrasonic through-transmission raster trajectory until reaching about 30ᵒC. From the obtained images, the normalized AC and its temporal derivative as a function of temperature and time were registered. The results have demonstrated high correlation (R² > 0.92) between both the brain AC and its temporal derivative to temperature. This indicates the validity of the hypothesis and the possibility of obtaining brain tissue temperature estimation from the temporal AC thermal changes. It is important to note that each brain yielded different AC values and slopes. This implies that a calibration step is required for each specimen. Thus, for a practical acoustic monitoring of the brain, two steps are suggested. The first step consists of simply measuring the AC at normal body temperature. The second step entails measuring the AC after small temperature elevation. In face of the urging need for a more accessible thermal monitoring technique for brain treatments, the proposed methodology enables a cost-effective high temporal resolution acoustical temperature estimation during HIFU treatments.

Keywords: attenuation coefficient, brain, HIFU, image-guidance, temperature

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229 A Comparative Assessment of Industrial Composites Using Thermography and Ultrasound

Authors: Mosab Alrashed, Wei Xu, Stephen Abineri, Yifan Zhao, Jörn Mehnen

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Thermographic inspection is a relatively new technique for Non-Destructive Testing (NDT) which has been gathering increasing interest due to its relatively low cost hardware and extremely fast data acquisition properties. This technique is especially promising in the area of rapid automated damage detection and quantification. In collaboration with a major industry partner from the aerospace sector advanced thermography-based NDT software for impact damaged composites is introduced. The software is based on correlation analysis of time-temperature profiles in combination with an image enhancement process. The prototype software is aiming to a) better visualise the damages in a relatively easy-to-use way and b) automatically and quantitatively measure the properties of the degradation. Knowing that degradation properties play an important role in the identification of degradation types, tests and results on specimens which were artificially damaged have been performed and analyzed.

Keywords: NDT, correlation analysis, image processing, damage, inspection

Procedia PDF Downloads 507
228 The Role of Intraluminal Endoscopy in the Diagnosis and Treatment of Fluid Collections in Patients With Acute Pancreatitis

Authors: A. Askerov, Y. Teterin, P. Yartcev, S. Novikov

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Introduction: Acute pancreatitis (AP) is a socially significant problem for public health and continues to be one of the most common causes of hospitalization of patients with pathology of the gastrointestinal tract. It is characterized by high mortality rates, which reaches 62-65% in infected pancreatic necrosis. Aims & Methods: The study group included 63 patients who underwent transluminal drainage (TLD) fluid collection (FC). All patients were performed transabdominal ultrasound, computer tomography of the abdominal cavity and retroperitoneal organs and endoscopic ultrasound (EUS) of the pancreatobiliary zone. The EUS was used as a final diagnostic method to determine the characteristics of FC. The indications for TLD were: the distance between the wall of the hollow organ and the FC was not more than 1 cm, the absence of large vessels on the puncture trajectory (more than 3 mm), and the size of the formation was more than 5 cm. When a homogeneous cavity with clear, even contours was detected, a plastic stent with rounded ends (“double pig tail”) was installed. The indication for the installation of a fully covered self-expanding stent was the detection of nonhomogeneous anechoic FC with hyperechoic inclusions and cloudy purulent contents. In patients with necrotic forms after drainage of the purulent cavity, a cystonasal drainage with a diameter of 7Fr was installed in its lumen under X-ray control to sanitize the cavity with a 0.05% aqueous solution of chlorhexidine. Endoscopic necrectomy was performed every 24-48 hours. The plastic stent was removed in 6 month, the fully covered self-expanding stent - in 1 month after the patient was discharged from the hospital. Results: Endoscopic TLD was performed in 63 patients. The FC corresponding to interstitial edematous pancreatitis was detected in 39 (62%) patients who underwent TLD with the installation of a plastic stent with rounded ends. In 24 (38%) patients with necrotic forms of FC, a fully covered self-expanding stent was placed. Communication with the ductal system of the pancreas was found in 5 (7.9%) patients. They underwent pancreaticoduodenal stenting. A complicated postoperative period was noted in 4 (6.3%) cases and was manifested by bleeding from the zone of pancreatogenic destruction. In 2 (3.1%) cases, this required angiography and endovascular embolization a. gastroduodenalis, in 1 (1.6%) case, endoscopic hemostasis was performed by filling the cavity with 4 ml of Hemoblock hemostatic solution. The combination of both methods was used in 1 (1.6%) patient. There was no evidence of recurrent bleeding in these patients. Lethal outcome occurred in 4 patients (6.3%). In 3 (4.7%) patients, the cause of death was multiple organ failure, in 1 (1.6%) - severe nosocomial pneumonia that developed on the 32nd day after drainage. Conclusions: 1. EUS is not only the most important method for diagnosing FC in AP, but also allows you to determine further tactics for their intraluminal drainage.2. Endoscopic intraluminal drainage of fluid zones in 45.8% of cases is the final minimally invasive method of surgical treatment of large-focal pancreatic necrosis. Disclosure: Nothing to disclose.

Keywords: acute pancreatitis, fluid collection, endoscopy surgery, necrectomy, transluminal drainage

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227 Hierarchical Porous Carbon Composite Electrode for High Performance Supercapacitor Application

Authors: Chia-Chia Chang, Jhen-Ting Huang, Hu-Cheng Weng, An-Ya Lo

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This study developed a simple hierarchical porous carbon (HPC) synthesis process and used for supercapacitor application. In which, mesopore provides huge specific surface area, meanwhile, macropore provides excellent mass transfer. Thus the hierarchical porous electrode improves the charge-discharge performance. On the other hand, cerium oxide (CeO2) have also got a lot research attention owing to its rich in content, low in price, environmentally friendly, good catalytic properties, and easy preparation. Besides, a rapid redox reaction occurs between trivalent cerium and tetravalent cerium releases oxygen atom and increase the conductivity. In order to prevent CeO2 from disintegration under long-term charge-discharge operation, the CeO2 carbon porous materials were was integrated as composite material in this study. For in the ex-situ analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) analysis were adopted to identify the surface morphology, crystal structure, and microstructure of the composite. 77K Nitrogen adsorption-desorption analysis was used to analyze the porosity of each specimen. For the in-situ test, cyclic voltammetry (CV) and chronopotentiometry (CP) were conducted by potentiostat to understand the charge and discharge properties. Ragone plot was drawn to further analyze the resistance properties. Based on above analyses, the effect of macropores/mespores and the CeO2/HPC ratios on charge-discharge performance were investigated. As a result, the capacitance can be greatly enhanced by 2.6 times higher than pristine mesoporous carbon electrode.

Keywords: hierarchical porous carbon, cerium oxide, supercapacitor

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226 Direct Contact Ultrasound Assisted Drying of Mango Slices

Authors: E. K. Mendez, N. A. Salazar, C. E. Orrego

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There is undoubted proof that increasing the intake of fruit lessens the risk of hypertension, coronary heart disease, stroke, and probable evidence that lowers the risk of cancer. Proper fruit drying is an excellent alternative to make their shelf-life longer, commercialization easier, and ready-to-eat healthy products or ingredients. The conventional way of drying is by hot air forced convection. However, this process step often requires a very long residence time; furthermore, it is highly energy consuming and detrimental to the product quality. Nowadays, power ultrasound (US) technic has been considered as an emerging and promising technology for industrial food processing. Most of published works dealing with drying food assisted by US have studied the effect of ultrasonic pre-treatment prior to air-drying on food and the airborne US conditions during dehydration. In this work a new approach was tested taking in to account drying time and two quality parameters of mango slices dehydrated by convection assisted by 20 KHz power US applied directly using a holed plate as product support and sound transmitting surface. During the drying of mango (Mangifera indica L.) slices (ca. 6.5 g, 0.006 m height and 0.040 m diameter), their weight was recorded every hour until final moisture content (10.0±1.0 % wet basis) was reached. After previous tests, optimization of three drying parameters - frequencies (2, 5 and 8 minutes each half-hour), air temperature (50-55-60⁰C) and power (45-70-95W)- was attempted by using a Box–Behnken design under the response surface methodology for the optimal drying time, color parameters and rehydration rate of dried samples. Assays involved 17 experiments, including a quintuplicate of the central point. Dried samples with and without US application were packed in individual high barrier plastic bags under vacuum, and then stored in the dark at 8⁰C until their analysis. All drying assays and sample analysis were performed in triplicate. US drying experimental data were fitted with nine models, among which the Verna model resulted in the best fit with R2 > 0.9999 and reduced χ2 ≤ 0.000001. Significant reductions in drying time were observed for the assays that used lower frequency and high US power. At 55⁰C, 95 watts and 2 min/30 min of sonication, 10% moisture content was reached in 211 min, as compared with 320 min for the same test without the use of US (blank). Rehydration rates (RR), defined as the ratio of rehydrated sample weight to that of dry sample and measured, was also larger than those of blanks and, in general, the higher the US power, the greater the RR. The direct contact and intermittent US treatment of mango slices used in this work improve drying rates and dried fruit rehydration ability. This technique can thus be used to reduce energy processing costs and the greenhouse gas emissions of fruit dehydration.

Keywords: ultrasonic assisted drying, fruit drying, mango slices, contact ultrasonic drying

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225 Using Probabilistic Neural Network (PNN) for Extracting Acoustic Microwaves (Bulk Acoustic Waves) in Piezoelectric Material

Authors: Hafdaoui Hichem, Mehadjebia Cherifa, Benatia Djamel

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In this paper, we propose a new method for Bulk detection of an acoustic microwave signal during the propagation of acoustic microwaves in a piezoelectric substrate (Lithium Niobate LiNbO3). We have used the classification by probabilistic neural network (PNN) as a means of numerical analysis in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the Bulk waves easily. These singularities inform us of presence of Bulk waves in piezoelectric materials. By which we obtain accurate values for each of the coefficient attenuation and acoustic velocity for Bulk waves. This study will be very interesting in modeling and realization of acoustic microwaves devices (ultrasound) based on the propagation of acoustic microwaves.

Keywords: piezoelectric material, probabilistic neural network (PNN), classification, acoustic microwaves, bulk waves, the attenuation coefficient

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224 Early Age Microstructural Analysis of Cement-Polymer Composite Paste Cured at High Temperature

Authors: Bertilia L. Bartley, Ledjane S. Barreto

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As a preliminary investigation on the control of microcracking in composite cement pastes, this study explores and compares the compatibility of Tetraethyl Orthosilicate (TEOS), Ethylene Glycol (EG) and Silicone Resin (SIL) in cement pastes cured at high temperature. Pastes were prepared by incorporating ordinary Portland cement (OPC) into an additive solution, using a solution/cement ratio of 0.45. Specimens were molded for 24h at 21 ± 2°C, then cured in deionized water for another 24h at 74 ± 1°C. TEOS and EG influence on fresh paste properties were similar to the reference OPC paste yet disintegration was observed in EG and SIL specimens after the first 12h of curing. X-Ray Diffraction analysis (XRD) coupled with thermogravimetric analysis (TGA/DTG) verified that SIL addition impedes portlandite formation significantly. Backscatter Scanning Electron Microscopy (SEM) techniques were therefore performed on selected areas of each sample to investigate the morphology of the hydration products detected. Various morphologies of portlandite crystals were observed in pastes with EG and TEOS addition, as well as dense morphologies of calcium silicate hydrate (C-S-H) gel and fibers, and ettringite needles. However, the formation of portlandite aggregate and clusters of C-S-H was highly favored by TEOS addition. Furthermore, the microstructural details of composite pastes were clearly visible at low magnifications i.e. 500x, as compared to the OPC paste. The results demonstrate accelerated hydration within composite pastes, a uniform distribution of hydration products, as well as an adhesive interaction with the products and polymer additive. Overall, TEOS demonstrated the most favorable influence, which indicates the potential of TEOS as a compatible polymer additive within the cement system at high temperature.

Keywords: accelerated curing, cement/polymer composite, hydration, microstructural properties, morphology, portlandite, scanning electron microscopy (sem)

Procedia PDF Downloads 151
223 Antifungal Susceptibility of Saprolegnia parasitica Isolated from Rainbow Trout and Its Host Pathogen Interaction in Zebrafish Disease Model

Authors: Sangyeop Shin, D. C. M. Kulatunga, S. H. S. Dananjaya, Chamilani Nikapitiya, Jehee Lee, Mahanama De Zoysa

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Saprolegniasis is one of the most devastating fungal diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated fungi belong to the member of S. parasitica, supported by its typical fungal features including cotton-like whitish mycelium, zoospores (primary and secondary) and phylogenetic analysis with internal transcribed spacer (ITS) region. Pathogenicity of isolated S. parasitica was developed in embryo, larvae, juvenile and adult zebrafish as a disease model. Up regulation of host genes encoding ZfTnf-α, Zfc-Rel, ZfIl-12, ZfLyz-c, Zfβ-def, and ZfHsp-70 was identified in zebrafish larvae after experimental challenge of S. parasitica showing the host immune responses against the S. parasitica. Survival of the juveniles upon fungal infection might be due to the increased immune protection in the host. Investigation of antifungal susceptibility of S. parasitica with natural lawsone (2-hydroxy-1,4-naphthoquinone) revealed the minimum inhibitory concentration (MIC) and percentage inhibition of radial growth (PIRG %) as 200 µg/mL and 31.8%, respectively. Lawsone was able to change the membrane permeability, and cause irreversible damage and disintegration to the cellular membranes of S. parasitica which might have effect on fungi growth inhibition. Moreover, the mycelium exposed to lawsone (MIC level) changed the transcriptional responses of S. parasitica genes. Overall results indicate that lawsone could be a potential and novel anti-S. parasitica agent for controlling S. parasitica infection.

Keywords: host-pathogen interactions, lawsone, rainbow trout, Saprolegnia parasitica, Saprolegniasis, zebrafish

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222 Curcumin-Loaded Phenethyl Isothiocyanate Nano-Spheres: Preparation, Stability Study, and Its Implication for Cataract Prevention

Authors: Pankaj Dinesh Baviskar

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This study examines the impact of curcumin-loaded nano-spheres in the form of emulsions on fish eye cataracts. Curcumin nanoemulsions were prepared by using phenethyl isothiocyanate. Nanoemulsions were synthesized by ultrasound-assisted method at 150 Watt. A zeta potential measurement for curcumin-loaded nanoemulsions was found to be -30.7eV, -13.4eV, and -9.55eV, and particle size was found to be 149.3 nm, 245.3 and nm 403.5 nm using particle size analyzer respectively for different conditions. The surface morphology of nano-spheres was examined by FE-SEM analysis. The zeta potential measured indicates its stability for corresponding nano-spheres. The anti-cataract application was studied by using isolated fish eye lenses. The cataract was induced using high glucose concentrated solution. The biochemical parameters in the form of reduced glutathione were measured to interpret the anti-cataract ability of curcumin-loaded nanoemulsions.

Keywords: curcumin, nano, cataract, nanoemulsion

Procedia PDF Downloads 80
221 A FE-Based Scheme for Computing Wave Interaction with Nonlinear Damage and Generation of Harmonics in Layered Composite Structures

Authors: R. K. Apalowo, D. Chronopoulos

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A Finite Element (FE) based scheme is presented for quantifying guided wave interaction with Localised Nonlinear Structural Damage (LNSD) within structures of arbitrary layering and geometric complexity. The through-thickness mode-shape of the structure is obtained through a wave and finite element method. This is applied in a time domain FE simulation in order to generate time harmonic excitation for a specific wave mode. Interaction of the wave with LNSD within the system is computed through an element activation and deactivation iteration. The scheme is validated against experimental measurements and a WFE-FE methodology for calculating wave interaction with damage. Case studies for guided wave interaction with crack and delamination are presented to verify the robustness of the proposed method in classifying and identifying damage.

Keywords: layered structures, nonlinear ultrasound, wave interaction with nonlinear damage, wave finite element, finite element

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220 Microstructure Study of NanoCrystalline Cellulose Obtained from Cotton Linter

Authors: Farid Amidi-Fazli

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Problems and disadvantages of using conventional plastics are more apparent in recent years and have attracted researchers' attention. Polymers from natural resources or bio polymers represent a suitable replacement to overcome to the disadvantages of plastics. But due to the some flaws of bio polymers, using suitable filler almost seems necessary. Nanocrystalline cellulose with low cost and availability can be applied as appropriate filler. In this study nanocrystalline cellulose was produced from cotton Linter and was characterized. The cotton Linter was hydrolyzed in sulfuric acid then neutralized by the two different concentrations of NaOH. The resulted suspension was treated by ultrasound waves. Process efficiency was determined as 90%. The final product was studied using scanning electron microscopy and x-ray diffraction technique. The obtained diagram of XRD experiment confirmed that the produced material was nanocrystalline cellulose. Also percentage of crystallinity was calculated as 84% in the obtained material as well as the size of crystals. It can be said that the applied method is a rapid and easy method for the production of nanocrystalline cellulose.

Keywords: nanocrystalline cellulose, crystallinity, XRD, cotton linter

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219 Design and Optimization of a 6 Degrees of Freedom Co-Manipulated Parallel Robot for Prostate Brachytherapy

Authors: Aziza Ben Halima, Julien Bert, Dimitris Visvikis

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In this paper, we propose designing and evaluating a parallel co-manipulated robot dedicated to low-dose-rate prostate brachytherapy. We developed 6 degrees of freedom compact and lightweight robot easy to install in the operating room thanks to its parallel design. This robotic system provides a co-manipulation allowing the surgeon to keep control of the needle’s insertion and consequently to improve the acceptability of the plan for the clinic. The best dimension’s configuration was solved by calculating the geometric model and using an optimization approach. The aim was to ensure the whole coverage of the prostate volume and consider the allowed free space around the patient that includes the ultrasound probe. The final robot dimensions fit in a cube of 300 300 300 mm³. A prototype was 3D printed, and the robot workspace was measured experimentally. The results show that the proposed robotic system satisfies the medical application requirements and permits the needle to reach any point within the prostate.

Keywords: medical robotics, co-manipulation, prostate brachytherapy, optimization

Procedia PDF Downloads 170
218 A Portable Device for Pulse Wave Velocity Measurements

Authors: Chien-Lin Wang, Cha-Ling Ko, Tainsong Chen

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Pulse wave velocity (PWV) of blood flow provides important information of vessel property and blood pressure which can be used to assess cardiovascular disease. However, the above measurements need expensive equipment, such as Doppler ultrasound, MRI, angiography etc. The photoplethysmograph (PPG) signals are commonly utilized to detect blood volume changes. In this study, two infrared (IR) probes are designed and placed at a fixed distance from finger base and fingertip. An analog circuit with automatic gain adjustment is implemented to get the stable original PPG signals from above two IR probes. In order to obtain the time delay precisely between two PPG signals, we obtain the pulse transit time from the second derivative of the original PPG signals. To get a portable, wireless and low power consumption PWV measurement device, the low energy Bluetooth 4.0 (BLE) and the microprocessor (Cortex™-M3) are used in this study. The PWV is highly correlated with blood pressure. This portable device has potential to be used for continuous blood pressure monitoring.

Keywords: pulse wave velocity, photoplethysmography, portable device, biomedical engineering

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217 Extraction of Natural Colorant from the Flowers of Flame of Forest Using Ultrasound

Authors: Sunny Arora, Meghal A. Desai

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An impetus towards green consumerism and implementation of sustainable techniques, consumption of natural products and utilization of environment friendly techniques have gained accelerated acceptance. Butein, a natural colorant, has many medicinal properties apart from its use in dyeing industries. Extraction of butein from the flowers of flame of forest was carried out using ultrasonication bath. Solid loading (2-6 g), extraction time (30-50 min), volume of solvent (30-50 mL) and types of solvent (methanol, ethanol and water) have been studied to maximize the yield of butein using the Taguchi method. The highest yield of butein 4.67% (w/w) was obtained using 4 g of plant material, 40 min of extraction time and 30 mL volume of methanol as a solvent. The present method provided a greater reduction in extraction time compared to the conventional method of extraction. Hence, the outcome of the present investigation could further be utilized to develop the method at a higher scale.

Keywords: butein, flowers of Flame of the Forest, Taguchi method, ultrasonic bath

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216 Pilomatrixoma of the Left Infra-Orbital Region in a 9 Year Old

Authors: Zainab Shaikh, Yusuf Miyanji

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Pilomatrixoma is a benign neoplasm of the hair follicle matrix that is not commonly diagnosed in general practice. This is a case report of a 9-year-old boy who presented with a one-year history of a 19mm x 11 mm swelling in the left infra-orbital region. This was previously undiagnosed in Spain, where the patient resided at the time of initial presentation, due to the language barrier the patient’s family encountered. An ultrasound and magnetic resonance imaging gave useful information regarding surrounding structures for complete tumor excision and indicated that the risk of facial nerve palsy is low. The lesion was surgically excised and a definitive diagnosis was made after histopathology. Pilomatrixoma, although not rare in its occurrence, is rarely this large at the time of excision due to early presentation. This case highlights the importance of including pilomatrixoma in the differential diagnosis of dermal and subcutaneous lesions in the head and neck region, as it is often misdiagnosed due to the lack of awareness of its clinical presentation.

Keywords: pilomatrixoma, swelling, infra-orbital, facial swelling

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215 Preparation and Characterization of Nanocrystalline Cellulose from Acacia mangium

Authors: Samira Gharehkhani, Seyed Farid Seyed Shirazi, Abdolreza Gharehkhani, Hooman Yarmand, Ahmad Badarudin, Rushdan Ibrahim, Salim Newaz Kazi

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Nanocrystalline cellulose (NCC) were prepared by acid hydrolysis and ultrasound treatment of bleached Acacia mangium fibers. The obtained rod-shaped nanocrystals showed a uniform size. The results showed that NCC with high crystallinity can be obtained using 64 wt% sulfuric acid. The effect of synthesis condition was investigated. Different reaction times were examined to produce the NCC and the results revealed that an optimum reaction time has to be used for preparing the NCC. Morphological investigation was performed using the transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were performed. X-ray diffraction (XRD) analysis revealed that the crystallinity increased with successive treatments. The NCC suspension was homogeneous and stable and no sedimentation was observed for a long time.

Keywords: acid hydrolysis, nanocrystalline cellulose, nano material, reaction time

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214 Evaluation of Carbon Dioxide Pressure through Radial Velocity Difference in Arterial Blood Modeled by Drift Flux Model

Authors: Aicha Rima Cheniti, Hatem Besbes, Joseph Haggege, Christophe Sintes

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In this paper, we are interested to determine the carbon dioxide pressure in the arterial blood through radial velocity difference. The blood was modeled as a two phase mixture (an aqueous carbon dioxide solution with carbon dioxide gas) by Drift flux model and the Young-Laplace equation. The distributions of mixture velocities determined from the considered model permitted the calculation of the radial velocity distributions with different values of mean mixture pressure and the calculation of the mean carbon dioxide pressure knowing the mean mixture pressure. The radial velocity distributions are used to deduce a calculation method of the mean mixture pressure through the radial velocity difference between two positions which is measured by ultrasound. The mean carbon dioxide pressure is then deduced from the mean mixture pressure.

Keywords: mean carbon dioxide pressure, mean mixture pressure, mixture velocity, radial velocity difference

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213 Multiple Approaches for Ultrasonic Cavitation Monitoring of Oxygen-Loaded Nanodroplets

Authors: Simone Galati, Adriano Troia

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Ultrasound (US) is widely used in medical field for a variety diagnostic techniques but, in recent years, it has also been creating great interest for therapeutic aims. Regarding drug delivery, the use of US as an activation source provides better spatial delivery confinement and limits the undesired side effects. However, at present there is no complete characterization at a fundamental level of the different signals produced by sono-activated nanocarriers. Therefore, the aim of this study is to obtain a metrological characterization of the cavitation phenomena induced by US through three parallel investigation approaches. US was focused into a channel of a customized phantom in which a solution with oxygen-loaded nanodroplets (OLNDs) was led to flow and the cavitation activity was monitored. Both quantitative and qualitative real-time analysis were performed giving information about the dynamics of bubble formation, oscillation and final implosion with respect to the working acoustic pressure and the type of nanodroplets, compared with pure water. From this analysis a possible interpretation of the observed results is proposed.

Keywords: cavitation, drug delivery, nanodroplets, ultra-sound

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212 Nanocellulose Incorporated Polyvinyl Alcohol Hydrogel

Authors: Rosli Mohd Yunus, Zianor Azrina Zianon Abdin, Mohammad Dalour Hossen Beg, Ridzuan Ramli

Abstract:

Recently, nanocrystalline cellulose (NCC) has gained considerable interest as a promising biomaterial due to their outstanding properties such as high surface area, high mechanical properties, hydrophilicity, biocompatibility and biodegradability. The NCC also has good stability in water which is compatible for mixing of water based polymer solution or emulsions with NCC. Oil palm empty fruit bunch (EFB) contained different amount of lignocellulosic materials such as lignin, hemicellulose and cellulose. Cellulose is the most significant materials that can be extracted from EFB as nanocrystalline cellulose (NCC). In this work the nanocrystalline cellulose were produced through acid hydrolysis together with ultrasound technique. The morphology of NCC was characterized by TEM, thermal behavior has been studied with DSC, TGA analysis. Structural properties were illustrated X-Ray diffraction as well as FTIR. The hydrogel was produced using polyvinyl alcohol (PVA) with different concentration of NCC. The hydrogel composite was characterized by swelling ratio, crosslinking density, mechanical properties and morphology.

Keywords: nanocellulose, oil palm, hydrogel, water treatment

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211 Screening of Congenital Heart Diseases with Fetal Phonocardiography

Authors: F. Kovács, K. Kádár, G. Hosszú, Á. T. Balogh, T. Zsedrovits, N. Kersner, A. Nagy, Gy. Jeney

Abstract:

The paper presents a novel screening method to indicate congenital heart diseases (CHD), which otherwise could remain undetected because of their low level. Therefore, not belonging to the high-risk population, the pregnancies are not subject to the regular fetal monitoring with ultrasound echocardiography. Based on the fact that CHD is a morphological defect of the heart causing turbulent blood flow, the turbulence appears as a murmur, which can be detected by fetal phonocardiography (fPCG). The proposed method applies measurements on the maternal abdomen and from the recorded sound signal a sophisticated processing determines the fetal heart murmur. The paper describes the problems and the additional advantages of the fPCG method including the possibility of measurements at home and its combination with the prescribed regular cardiotocographic (CTG) monitoring. The proposed screening process implemented on a telemedicine system provides an enhanced safety against hidden cardiac diseases.

Keywords: cardiac murmurs, fetal phonocardiography, screening of CHDs, telemedicine system

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210 The Role of Uterine Artery Embolization in the Management of Postpartum Hemorrhage

Authors: Chee Wai Ku, Pui See Chin

Abstract:

As an emerging alternative to hysterectomy, uterine artery embolization (UAE) has been widely used in the management of fibroids and in controlling postpartum hemorrhage (PPH) unresponsive to other therapies. Research has shown UAE to be a safe, minimally invasive procedure with few complications and minimal effects on future fertility. We present two cases highlighting the use of UAE in preventing PPH in a patient with a large fibroid at the time of cesarean section and in the treatment of secondary PPH refractory to other therapies in another patient. We present a 36-year primiparous woman who booked at 18+6 weeks gestation with a 13.7 cm subserosal fibroid at the lower anterior wall of the uterus near the cervix and a 10.8 cm subserosal fibroid in the left wall. Prophylactic internal iliac artery occlusion balloons were placed prior to the planned classical midline cesarean section. The balloons were inflated once the baby was delivered. Bilateral uterine arteries were embolized subsequently. The estimated blood loss (EBL) was 400 mls and hemoglobin (Hb) remained stable at 10 g/DL. Ultrasound scan 2 years postnatally showed stable uterine fibroids 10.4 and 7.1 cm, which was significantly smaller than before. We present the second case of a 40-year-old G2P1 with a previous cesarean section for failure to progress. There were no antenatal problems, and the placenta was not previa. She presented with term labour and underwent an emergency cesarean section for failed vaginal birth after cesarean. Intraoperatively extensive adhesions were noted with bladder drawn high, and EBL was 300 mls. Postpartum recovery was uneventful. She presented with secondary PPH 3 weeks later complicated by hypovolemic shock. She underwent an emergency examination under anesthesia and evacuation of the uterus, with EBL 2500mls. Histology showed decidua with chronic inflammation. She was discharged well with no further PPH. She subsequently returned one week later for secondary PPH. Bedside ultrasound showed that the endometrium was thin with no evidence of retained products of conception. Uterotonics were administered, and examination under anesthesia was performed, with uterine Bakri balloon and vaginal pack insertion after. EBL was 1000 mls. There was no definite cause of PPH with no uterine atony or products of conception. To evaluate a potential cause, pelvic angiogram and super selective left uterine arteriogram was performed which showed profuse contrast extravasation and acute bleeding from the left uterine artery. Superselective embolization of the left uterine artery was performed. No gross contrast extravasation from the right uterine artery was seen. These two cases demonstrated the superior efficacy of UAE. Firstly, the prophylactic use of intra-arterial balloon catheters in pregnant patients with large fibroids, and secondly, in the diagnosis and management of secondary PPH refractory to uterotonics and uterine tamponade. In both cases, the need for laparotomy hysterectomy was avoided, resulting in the preservation of future fertility. UAE should be a consideration for hemodynamically stable patients in centres with access to interventional radiology.

Keywords: fertility preservation, secondary postpartum hemorrhage, uterine embolization, uterine fibroids

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209 FZP Design Considering Spherical Wave Incidence

Authors: Sergio Pérez-López, Daniel Tarrazó-Serrano, José M. Fuster, Pilar Candelas, Constanza Rubio

Abstract:

Fresnel Zone Plates (FZPs) are widely used in many areas, such as optics, microwaves or acoustics. On the design of FZPs, plane wave incidence is typically considered, but that is not usually the case in ultrasounds, especially in applications where a piston emitter is placed at a certain distance from the lens. In these cases, having control of the focal distance is very important, and with the usual Fresnel equation a focal displacement from the theoretical distance is observed due to the plane wave supposition. In this work, a comparison between FZP with plane wave incidence design and FZP with point source design in the case of piston emitter is presented. Influence of the main parameters of the piston in the final focalization profile has been studied. Numerical models and experimental results are shown, and they prove that when spherical wave incidence is considered for the piston case, it is possible to have a fine control of the focal distance in comparison with the classical design method.

Keywords: focusing, Fresnel zone plates, FZP, ultrasound

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208 Sonochemical Zinc Oxide and Layered Hydroxy Zinc Acetate Synthesis in Fenton-Like Reactions

Authors: Durata Haciu, Ozgur Birer

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Zinc acetate solution is sonicated at high power in water and in ethanol in the absence and presence of various peroxides. In the absence of peroxides, the products are zinc oxide and layered hydroxy zinc acetate in water and in ethanol, respectively. Layered basic zinc acetate are prepared for the first time using sonochemical methods. The addition of peroxides alters the reaction mechanisms. In water, insoluble peroxides produce zinc oxides while the water soluble peroxide, i.e.hydrogen peroxide, completely destroyed the structure and casted a doubt on the accepted peroxide initiated mechanism of reactions. In ethanol,peroxide addition caused the reaction mechanism to change and some oxide formation is observed. The reaction mechanism is sensitive to water/ethanol amounts as well as the peroxide to zinc ion mole ratio.Thin zinc oxide wafers (ca. 30 nm) with band gaps of 3.24 eV were obtained.

Keywords: ultrasound, zinc oxide, hydroxy zinc acetate, fenton, peroxide initiation

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207 Clinical Cases of Rare Types of 'Maturity Onset Diabetes of the Young' Diabetes

Authors: Alla Ovsyannikova, Oksana Rymar, Elena Shakhtshneider, Mikhail Voevoda

Abstract:

In Siberia endocrinologists increasingly noted young patients with the course of diabetes mellitus differing from 1 and 2 types. Therefore we did a molecular genetic study for this group of patients to verify the monogenic forms of diabetes mellitus in them and researched the characteristics of this pathology. When confirming the monogenic form of diabetes, we performed a correction therapy for many patients (transfer from insulin to tablets), prevented specific complications, examined relatives and diagnosed their diabetes at the preclinical stage, revealed phenotypic characteristics of the pathology which led to the high significance of this work. Materials and Methods: We observed 5 patients (4 families). We diagnosed MODY (Maturity Onset Diabetes of the Young) during the molecular genetic testing (direct automatic sequencing). All patients had a full clinical examination, blood samples for biochemical research, determination of C-peptide and TSH, antibodies to b-cells, microalbuminuria, abdominal ultrasound, heart and thyroid ultrasound, examination of ophthalmologist. Results: We diagnosed 3 rare types of MODY: two women had MODY8, one man – MODY6 and man and his mother - MODY12. Patients with types 8 and 12 had clinical features. Age of onset hyperglycemia ranged from 26 to 34 years. In a patient with MODY6 fasting hyperglycemia was detected during a routine examination. Clinical symptoms, complications were not diagnosed. The patient observes a diet. In the first patient MODY8 was detected during first pregnancy, she had itchy skin and mostly postprandial hyperglycemia. Upon examination we determined glycated hemoglobin 7.5%, retinopathy, non-proliferative stage, peripheral neuropathy. She uses a basic bolus insulin therapy. The second patient with MODY8 also had clinical manifestations of hyperglycemia (pruritus, thirst), postprandial hyperglycemia and diabetic nephropathy, a stage of microalbuminuria. The patient was diagnosed autoimmune thyroiditis. She used inhibitors of DPP-4. The patient with MODY12 had an aggressive course. In the detection of hyperglycemia he had complaints of visual impairment, intense headaches, leg cramps. The patient had a history of childhood convulsive seizures of non-epileptic genesis, without organic pathology, which themselves were stopped at the age of 12 years. When we diagnosed diabetes a patient was 28 years, he had hypertriglyceridemia, atherosclerotic plaque in the carotid artery, proliferative retinopathy (lacerocoagulation). Diabetes and early myocardial infarction were observed in three cases in family. We prescribe therapy with sulfonylureas and SGLT-2 inhibitors with a positive effect. At the patient's mother diabetes began at a later age (30 years) and a less aggressive course was observed. She also has hypertriglyceridemia and uses oral hypoglycemic drugs. Conclusions: 1) When young patients with hyperglycemia have extrapancreatic pathologies and diabetic complications with a short duration of diabetes we can assume they have one of type of MODY diabetes. 2) In patients with monogenic forms of diabetes mellitus, the clinical manifestations of hyperglycemia in each succeeding generation are revealed at an earlier age. Research had increased our knowledge of the monogenic forms of diabetes. The reported study was supported by RSCF, research project No. 14-15-00496-P.

Keywords: diabetes mellitus, MODY diabetes, monogenic forms, young patients

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206 Recovery of Polyphenolic Phytochemicals From Greek Grape Pomace (Vitis Vinifera L.)

Authors: Christina Drosou, Konstantina E. Kyriakopoulou, Andreas Bimpilas, Dimitrios Tsimogiannis, Magdalini C. Krokida

Abstract:

Rationale: Agiorgitiko is one of the most widely-grown and commercially well-established red wine varieties in Greece. Each year viticulture industry produces a large amount of waste consisting of grape skins and seeds (pomace) during a short period. Grapes contain polyphenolic compounds which are partially transferred to wine during winemaking. Therefore, winery wastes could be an alternative cheap source for obtaining such compounds with important antioxidant activity. Specifically, red grape waste contains anthocyanins and flavonols which are characterized by multiple biological activities, including cardioprotective, anti-inflammatory, anti-carcinogenic, antiviral and antibacterial properties attributed mainly to their antioxidant activity. Ultrasound assisted extraction (UAE) is considered an effective way to recover phenolic compounds, since it combines the advantage of mechanical effect with low temperature. Moreover, green solvents can be used in order to recover extracts intended for used in the food and nutraceutical industry. Apart from the extraction, pre-treatment process like drying can play an important role on the preservation of the grape pomace and the enhancement of its antioxidant capacity. Objective: The aim of this study is to recover natural extracts from winery waste with high antioxidant capacity using green solvents so they can be exploited and utilized as enhancers in food or nutraceuticals. Methods: Agiorgitiko grape pomace was dehydrated by air drying (AD) and accelerated solar drying (ASD) in order to explore the effect of the pre-treatment on the recovery of bioactive compounds. UAE was applied in untreated and dried samples using water and water: ethanol (1:1) as solvents. The total antioxidant potential and phenolic content of the extracts was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Folin-Ciocalteu method, respectively. Finally, the profile of anthocyanins and flavonols was specified using HPLC-DAD analysis. The efficiency of processes was determined in terms of extraction yield, antioxidant activity, phenolic content and the anthocyanins and flavovols profile. Results & Discussion: The experiments indicated that the pre-treatment was essential for the recovery of highly nutritious compounds from the pomace as long as the extracts samples showed higher phenolic content and antioxidant capacity. Water: ethanol (1:1) was considered a more effective solvent on the recovery of phenolic compounds. Moreover, ASD grape pomace extracted with the solvent system exhibited the highest antioxidant activity (IC50=0.36±0.01mg/mL) and phenolic content (TPC=172.68±0.01mgGAE/g dry extract), followed by AD and untreated pomace. The major compounds recovered were malvidin3-O-glucoside and quercetin3-O-glucoside according to the HPLC analysis. Conclusions: Winery waste can be exploited for the recovery of nutritious compounds using green solvents such as water or ethanol. The pretreatment of the pomace can significantly affect the concentration of phenolic compounds, while UAE is considered a highly effective extraction process.

Keywords: agiorgitico grape pomace, antioxidants, phenolic compounds, ultrasound assisted extraction

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