Search results for: surface displacement history

Authors: Temesgen Geremew

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Functionalized nanoparticles have emerged as a revolutionary class of materials with immense potential in various biomedical applications. These engineered nanoparticles possess unique properties tailored to interact with biological systems, offering unprecedented opportunities in drug delivery, imaging, diagnostics, and therapy. This research delves into the design, synthesis, and characterization of functionalized nanoparticles for targeted biomedical applications. The primary focus lies on developing nanoparticles with precisely controlled size, surface chemistry, and biocompatibility for specific medical purposes. The research will also explore the crucial interaction of these nanoparticles with biological systems, encompassing cellular uptake, biodistribution, and potential toxicity evaluation. The successful development of functionalized nanoparticles holds the promise to revolutionize various aspects of healthcare. This research aspires to contribute significantly to this advancement by providing valuable insights into the design and application of these versatile materials within the ever-evolving field of biomedicine.

Keywords: nanoparticles, biomedicals, cancer, biocompatibility

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Authors: Lian Wu, Mervyn Merrilees

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Chronic Obstructive Pulmonary Disease (COPD) is a worldwide problem, characterized by irreversible and progressive airflow obstruction. In New Zealand, it is currently the 4th commonest cause of death and exacerbations of COPD are a frequent cause of admission to hospital. Serum levels of Clara cell secretory protein-16 (CC-16) are believed to represent Clara cell toxicity. More recently, CC-16 has been found to be associated with smoker COPD. It is produced almost exclusively by non-ciliated Clara cells in the airways, and its primary function is to protect the lungs against oxidative stress and carcinogenesis. After acute exposure to cigarette smoke, serum levels of CC-16 become elevated. CC16 is a potent natural immune-suppressor and anti-inflammatory agent. In vitro, CC16 inhibits both monocyte and polymorphonuclear neutrophils chemotaxis and phagocytosis. CC16 also inhibits fibroblast chemotaxis. However, the role of CC-16 in non-smoking related COPD is still not clear. In this study, we investigated serum CC-16 levels in non-smoking related COPD. Methods: We compared non-smoker patients with COPD (FEV1<60% of predicted, FEV1/FVC <0.7, n=100) and individuals with normal lung function FEV1≥ 80% of predicted and FEV1/FVC≥ 0.7, n=80). All subjects had no smoking history. CC-16 was measured by ELISA. Results and conclusion: Serum CC-16 levels are reduced in individuals with non-smoking related COPD, and there is a weak correlation with disease severity in non-smoking related COPD group compared to non-smoker controls.

Keywords: COPD, CC-16, ELISA, non-smoking-related COPD

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Authors: Jenny Kwon

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Following the outbreak of the COVID-19 pandemic globally, another type of pandemic, ageism, appeared on the surface. Ageism, the stereotypes, prejudice, and discrimination directed towards others or oneself based on chronological age, has adversely impacted older adults' lives during the pandemic. In the short term, older adults struggled with health issues (e.g., high rate of infection and mortality) and experienced social disconnection (e.g., loneliness and depression). Ultimately, older adults' self-perceptions of aging, self-esteem and intergenerational relationships were negatively influenced. To closely look into the impact of ageism during the pandemic on U.S. older adults' aging process, the current study has three specific purposes. First, the study introduces a theoretical foundation (i.e., stereotype embodiment theory) in the development of ageism research. Second, the study reports on examples of ageism toward U.S. older adults manifested in the context of COVID-19. Finally, collective responsibilities and future research directions are proposed to fight against ageism.

Keywords: ageism, COVID-19, older adults, pandemic, stereotype embodiment

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Authors: Rudzani Lusunzi, Frans Waanders, Elvis Fosso-Kankeu, Robert Khashane Netshitungulwana

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The Sabie Goldfield has a history of gold mining dating back more than a century. Acid mine drainage (AMD) from the Nestor mine tailings storage facility (MTSF) poses a serious threat to the nearby ecosystem, specifically the Sabie River system. This study aims at developing mitigation measures for the AMD emanating from the Nestor MTSF using materials from the Glynns Lydenburg MTSF. The Nestor MTSF (NM) and the Glynns Lydenburg MTSF (GM) each provided about 20 kg of bulk composite samples. Using samples from the Nestor MTSF and the Glynns Lydenburg MTSF, two mixtures were created. MIX-A is a mixture that contains 25% weight percent (GM) and 75% weight percent (NM). MIX-B is the name given to the second mixture, which contains 50% AN and 50% AG. The same static test, i.e., acid–base accounting (ABA), net acid generation (NAG), and acid buffering characteristics curve (ABCC) was used to estimate the acid-generating probabilities of samples NM and GM for MIX-A and MIX-B. Furthermore, the mineralogy of the Nestor MTSF samples consists of the primary acid-producing mineral pyrite as well as the secondary minerals ferricopiapite and jarosite, which are common in acidic conditions. The Glynns Lydenburg MTSF samples, on the other hand, contain primary acid-neutralizing minerals calcite and dolomite. Based on the assessment conducted, materials from the Glynns Lydenburg are capable of neutralizing AMD from Nestor MTSF. Therefore, the alkaline tailings materials from the Glynns Lydenburg MTSF can be used to rehabilitate the acidic Nestor MTSF.

Keywords: Nestor Mine, acid mine drainage, mitigation, Sabie River system

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Authors: Elin Linder

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Ethnographic endeavors feature a long history of creative modes of engagements, and anthropology an equally long critique of its disciplinary attention to worded representations of beyond worded experiences. Curious and critical as our research comes about, takes place, unfolds, and develops, processes of documenting, exploring, experiencing, and producing knowledge commonly evolve as intrinsic parts of our situated wishes to make sense of the worlds we study. We may imagine to do one thing and to use a specific mode of fieldnoting, only to end up doing something else, such as to capture dynamics and dimensions otherwise not attentively engaged or even lost. This paper builds on such an experience, and it acts window to open the conversation for doing and representing ethnographic work as creatively as it was undertaken. Expressively and actively undertaken by means of sensuous scholarship, fieldworking in the world of olivicoltura in Apulia intriguingly advanced into resourcefully embodied research using a drone. While the drone first and foremost allowed perspectives that one as a human is largely and physically incapable of exploring, it rapidly emerged into a mode of engagement that probed critical question how one comes to learn how to see that which one watches, listen to that which one hears, smell that which one scents, feel that which one touch, and gather that which one experience. This paper develops how the drone incorporated a transition of a particularly situated ethnographic sense of attention, all while visualizing how imaginative conceptualizations enable unexpected modes of multimodal knowing in much multisensorial worlds of being.

Keywords: drone, multimodality, sensuous scholarship, critical creativity, ethnographic practice

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Authors: Mohamad Saeed Ahrari-Khafi, Abutorab Tabatabai-Naini, Niloofar Ajvadi

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Scapular fracture is not common in horses, due to the proper protection of scapular muscles. However, if it happens, it can cause lameness in horses. Because of the overlapping of the scapula on the contralateral scapula and the thorax, usually radiography cannot be helpful in evaluation, except in small amount of its ventral part. Although ultrasonography is mainly used for diagnosis of soft tissue injuries, it also can be used for evaluation of bone surface abnormalities. This study was intended to document the normal ultrasonographic appearance of the equine scapula. Right forelimb of six horses was used. To facilitate the image assessment, a zoning system was developed. Ultrasonography was performed by using a 5-11 MHz linear array transducer. Ultrasonographic anatomy of scapula in different parts and planes was imaged and documented, hoping to help practitioners to diagnose fractures and injuries. Results showed that ultrasonography is capable to depict different parts of the scapula and regional muscles, and can be used for detecting fractures and other abnormalities.

Keywords: horse, scapula, scapular fracture, ultrasonography

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Authors: Kritsada Pipitthapan

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WO3/SiO2 catalysts were modified by an ion exchange method with sodium hydroxide or potassium hydroxide solution. The performance of the modified catalysts was tested in the metathesis of ethylene and trans-2-butene to propylene. During ion exchange, sodium and potassium ions played different roles. Sodium modified catalysts revealed constant trans-2-butene conversion and propylene selectivity when the concentrations of sodium in the solution were varied. In contrast, potassium modified catalysts showed reduction of the conversion and increase of the selectivity. From these results, potassium hydroxide may affect the transformation of tungsten oxide active species, resulting in the decrease in conversion whereas sodium hydroxide did not. Moreover, the modification of catalysts by this method improved the catalyst stability by lowering the amount of coke deposited on the catalyst surface.

Keywords: acid sites, alkali metal, isomerization, metathesis

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Authors: Mahla Zabet, Navid Zanganeh, Hafez Balavi, Farbod Sharif

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Electrodeposition is a method for applying coatings with uniform thickness on complex objects. A conductive surface can be produced using the electrical current in this method. Carbon nanotubes are known to have high electrical conductivity and mechanical properties. In this report, NH2-multiwalled carbon nanotubes (MWCNTs) were used in epoxy resin with different weight percent. The weight percent of incorporated MWCNTS into the matrix was changed in the range of 0.6-3.6 wt% to obtain a series of electrocoatings. The electrocoats were then applied on steel substrates by a cathodic electrodeposition technique. Scanning electron microscopy (SEM) and optical microscopy were used to characterize the electrocoated films. The results illustrated the increase in conductivity by increasing of MWCNT load. However, at the percolation threshold, throwing power was dropped with increase in recoating ability.

Keywords: electrodeposition, carbon nanotube, electrical conductivity, throwing power

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Authors: Gansukh Erdenedelger, Doljinsuren Sukhbaatar, Trung Dung Dao, Byeong-Kyu Lee, Han Mo Jeong

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Two kinds of carboxylated thermally reduced graphenes (C-TRGs) having different lateral sizes are examined as a Pickering stabilizer in the suspension polymerization of methyl methacrylate. The size and the shape of the prepared composite particles are irregular due to agglomeration, more evidently when the larger C-TRG is used. In addition, C-TRG is distributed not only on the surface but also inside the composite particles. It indicates that the C-TRG alone is not a stable Pickering agent. However, a very small dosage of acrylic acid remedies all these issues, because acrylic acid interacts with C-TRG and synergizes the stabilizing effect. The compression molded composite of the core/shell poly(methyl methacrylate)/C-TRG particles exhibits a very low percolation threshold of electrical conductivity of 0.03 vol%. It demonstrates that the C-TRG shells of the composite particles effectively form a segregated conductive network throughout the composite.

Keywords: pickering, graphene, polymerization, PMMA

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Authors: Natasa Todorovic, Jovana Nikolov

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Guard detector efficiency, cosmic background, and its variation were determinate using ultra low-level liquid scintillation spectrometer Quantulus 1220, equipped with an anti-Compton guard detector, in the surface laboratory at the University of Novi Sad, Serbia, Atmospheric pressure variation has an observable effect on the anti-Compton guard detector count rate. and the cosmic muon flux is lower during a high-pressure period. Also, the guard detector Compton continuum provides a good view of the level of gamma radiation in the laboratory environment. The efficiency of the guard detector in the channel interval from 750 to 1024 was assessed to 93.45%; efficiency in the entire window (channels 1 to 1024) was 75.23%, which is in good agreement with literature data.

Keywords: cosmic radiation, background reduction, liquid scintillation counting, guard detector efficiency

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Authors: Azim Hilmy Mohamad Yusof, Muhamad Iqbal Mubarak Faharul Azman, Nur Azwin Ismail, Noer El Hidayah Ismail

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Infiltration is the process by which precipitation or water soaks into subsurface soils and moves into rocks through cracks and pore spaces. This paper explains how the water infiltration will be identified using 2-D resistivity imaging. Padang Minden, in Universiti Sains Malaysia, Penang has been chosen as the survey area during this study. The study area consists of microcline granite with grain size of medium to coarse. 2-D Resistivity Imaging survey is used to detect subsurface layer for many years by making measurements on the ground surface. The result shows that resistivity value of 0.015 Ωm - 10 Ωm represent the salt water intrusion zone while the resistivity value of 11 Ωm - 100 Ωm is suggested as the boundary zone between the salt water intrusion zone and low saturated zone.

Keywords: 2-D resistivity imaging, microcline granite, salt water intrusion, water infiltration

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Authors: Vanessa Roulet, Marc Turini, Juliane Hey, Stéphanie Bord-Romeu, Emilie Bonzom, Mahmoud Badawi, Mohammed-Amine Chakir, Valérie Simon, Vanessa Viotti, Jérémie Gautier, Françoise Le Boulaire, Catherine Coignard, Claire Vincent, Sandrine Greaume, Isabelle Voisin

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Background: Beckman Coulter, Inc. has recently developed fully automated assays for the detection of HBsAg on a new immunoassay platform. The objective of this European multicenter study was to evaluate the performance of the ACCESS HBsAg and ACCESS HBsAg Confirmatory assays† on the recently CE-marked DxI 9000 ACCESS Immunoassay Analyzer. Methods: The clinical specificity of the ACCESS HBsAg and HBsAg Confirmatory assays was determined using HBsAg-negative samples from blood donors and hospitalized patients. The clinical sensitivity was determined using presumed HBsAg-positive samples. Sample HBsAg status was determined using a CE-marked HBsAg assay (Abbott ARCHITECT HBsAg Qualitative II, Roche Elecsys HBsAg II, or Abbott PRISM HBsAg assay) and a CE-marked HBsAg confirmatory assay (Abbott ARCHITECT HBsAg Qualitative II Confirmatory or Abbott PRISM HBsAg Confirmatory assay) according to manufacturer package inserts and pre-determined testing algorithms. False initial reactive rate was determined on fresh hospitalized patient samples. The sensitivity for the early detection of HBV infection was assessed internally on thirty (30) seroconversion panels. Results: Clinical specificity was 99.95% (95% CI, 99.86 – 99.99%) on 6047 blood donors and 99.71% (95%CI, 99.15 – 99.94%) on 1023 hospitalized patient samples. A total of six (6) samples were found false positive with the ACCESS HBsAg assay. None were confirmed for the presence of HBsAg with the ACCESS HBsAg Confirmatory assay. Clinical sensitivity on 455 HBsAg-positive samples was 100.00% (95% CI, 99.19 – 100.00%) for the ACCESS HBsAg assay alone and for the ACCESS HBsAg Confirmatory assay. The false initial reactive rate on 821 fresh hospitalized patient samples was 0.24% (95% CI, 0.03 – 0.87%). Results obtained on 30 seroconversion panels demonstrated that the ACCESS HBsAg assay had equivalent sensitivity performances compared to the Abbott ARCHITECT HBsAg Qualitative II assay with an average bleed difference since first reactive bleed of 0.13. All bleeds found reactive in ACCESS HBsAg assay were confirmed in ACCESS HBsAg Confirmatory assay. Conclusion: The newly developed ACCESS HBsAg and ACCESS HBsAg Confirmatory assays from Beckman Coulter have demonstrated high clinical sensitivity and specificity, equivalent to currently marketed HBsAg assays, as well as a low false initial reactive rate. †Pending achievement of CE compliance; not yet available for in vitro diagnostic use. 2023-11317 Beckman Coulter and the Beckman Coulter product and service marks mentioned herein are trademarks or registered trademarks of Beckman Coulter, Inc. in the United States and other countries. All other trademarks are the property of their respective owners.

Keywords: dxi 9000 access immunoassay analyzer, hbsag, hbv, hepatitis b surface antigen, hepatitis b virus, immunoassay

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Authors: Selamawit Dires, Solomon Tesfamariam, Thomas Tannert

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Modern earthquake engineering and design encompass performance-based design philosophy. The main objective in performance-based design is to achieve a system performing precisely to meet the design objectives so to reduce unintended seismic risks and associated losses. Energy-based earthquake-resistant design is one of the design methodologies that can be implemented in performance-based earthquake engineering. In energy-based design, the seismic demand is usually described as the ratio of the hysteretic to input energy. Once the hysteretic energy is known as a percentage of the input energy, it is distributed among energy-dissipating components of a structure. The hysteretic to input energy ratio is highly dependent on the inherent damping of a structural system. In numerical analysis, damping can be modeled as stiffness-proportional, mass-proportional, or a linear combination of stiffness and mass. In this study, the effect of mathematical modeling of damping on the estimation of seismic energy demands is investigated by considering elastic-perfectly-plastic single-degree-of-freedom systems representing short to long period structures. Furthermore, the seismicity of Vancouver, Canada, is used in the nonlinear time history analysis. According to the preliminary results, the input energy demand is not sensitive to the type of damping models deployed. Hence, consistent results are achieved regardless of the damping models utilized in the numerical analyses. On the other hand, the hysteretic to input energy ratios vary significantly for the different damping models.

Keywords: damping, energy-based seismic design, hysteretic energy, input energy

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Authors: Zaw Z Aung

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Background: High-risk groups for hepatitis B infection (HBV) are people who injected drugs (PWID), men who have sex with men (MSM), people living with HIV (PLHIV) and persons with hepatitis C (HCV), etc. HBV/HCV coinfected patients are at increased risk of cirrhosis, hepatic decompensation and hepatocellular carcinoma. To the best of author’s knowledge, there is currently no data for hepatitis B vaccine utilization in HCV positive patients and their antibody response. Methodology: From February 2018 to May 2018, consented participants at or above 18 years who came to the clinic in Mandalay were tested with the anti-HCV rapid test. Those who tested HCV positive (n=168) were further tested with hepatitis B profile and asked about their previous hepatitis B vaccination history and risk factors. Results: Out of 168 HCV positive participants, three were excluded for active HBV infections. The remaining 165 were categorized into previously vaccinated 64% (n=106) and unvaccinated 36% (n=59) There were three characteristics groups- PWID monoinfected (n=77), General Population (GP) monoinfected (n=22) and HIV/HCV coinfected participants (n=66). Unvaccinated participants were highest in HIV/HCV, with 68%(n=45) followed by GP (23%, n=5) and PWID (12%, n=9). Among previously vaccinated participants, the highest percentage was PWID (88%, n=68), the second highest was GP (77%, n=17) and lowest in HIV/HCV patients (32%, n=21). 63 participants completed third doses of vaccination (PWID=36, GP=13, HIV/HCV=14). 53% of participants who completed 3 dose of hepatitis B were non-responders (n=34): HIV/HCV (86%, n=12), PWID (44%, n=16), and GP (46%, n=6) Conclusion: Even in the presence of effective and safe hepatitis B vaccine, uptake is low among high risk groups especially PLHIV that needs to be improved. Integration or collaboration of hepatitis B vaccination program, HIV/AIDS and hepatitis C treatment centers is desirable. About half of vaccinated participants were non-responders so that optimal doses, schedule and follow-up testing need to be addressed carefully for those groups.

Keywords: Hepatitis B vaccine, Hepatitis C, HIV, Myanmar

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Authors: S. Nouri

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In this study, the Si-aluminide coating was prepared on gamma-TiAl [Ti-45Al-2Nb-2Mn-1B (at. %)] via liquid-phase slurry procedure. The high temperature oxidation resistance of this diffusion coating was evaluated at 1100 °C for 400 hours. The results of the isothermal oxidation showed that the formation of Si-aluminide coating can remarkably improve the high temperature oxidation of bare gamma-TiAl alloy. The identification of oxide scale microstructure showed that the formation of protective Al₂O₃+SiO₂ mixed oxide scale along with a continuous, compact and uniform layer of Ti₅Si₃ beneath the surface oxide scale can act as an oxygen diffusion barrier during the high temperature oxidation. The other possible mechanisms related to the formation of Si-aluminide coating and oxide scales were also discussed.

Keywords: Gamma-TiAl alloy, high temperature oxidation, Si-aluminide coating, slurry procedure

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Authors: Leping Chen, Daoxiang An, Xiaotao Huang

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Automatic vehicle detection using synthetic aperture radar (SAR) image has been widely researched, as well as using optical remote sensing images. However, most researches treat the detection as an independent problem, failing to make full use of SAR data information. In circular SAR (CSAR), the two long borders of vehicle will shrink if the imaging surface is set higher than the reference one. Based on above variance, an automatic vehicle detection using CSAR image is proposed to enhance detection ability under complex environment, such as vehicles’ closely packing, which confuses the detector. The detection method uses the multiple images generated by different height plane to obtain an energy-concentrated image for detecting and then uses the maximally stable extremal regions method (MSER) to detect vehicles. A result of vehicles’ detection is given to verify the effectiveness and correctness of proposed method.

Keywords: circular SAR, vehicle detection, automatic, imaging

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Authors: Andrea Alfaro Barajas, Arturo I. Martinez

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3D photothermal structure of carbon was synthesized using PET bottles waste and sodium chloride through controlled carbonization. Characterization techniques such as X-ray photoelectron spectroscopy, X-ray diffraction, BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, spectrophotometry, and mechanical compression were carried out. The carbon showed physical integrity > 90%, an absorbance > 90% between 300-1000nm of the solar spectrum, and a high specific surface area from 450 to 620 m2/g. The X-ray was employed to examine the phase structure; the obtained pattern shows an amorphous material. A higher intensity of band D with respect to band G was confirmed by Raman Spectroscopy. C-OH, COOH, C-O, and C-C bonds were obtained from the deconvolution of the high-resolution C1s orbital. Macropores of 160 to 180µm and micropores of 0.5 to 2nm were observed by SEM and TEM images, respectively. Such combined characteristics of carbon confer efficient evaporation of water under 1 sun irradiation > 60%.

Keywords: solar-absorber, carbon, water-evaporation, interfacial

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Authors: Mohamed R. Al-Mulla, Bader Al-Bader, Firouz K. Ghaaedi, Francisco Sepulveda

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Surface electromyography (sEMG) is utilised in numerous studies on muscle activity. In the beginning, single electrodes were utilised; however, the newest approach is to use an array of electrodes or a grid of electrodes to improve the accuracy of the recorded reading. This research focuses on electrode placement on the biceps brachii, using an array of electrodes placed longitudinal and diagonally on the muscle belly. Trials were conducted on four healthy males, with sEMG signal acquisition from fatiguing isometric contractions. The signal was analysed using the power spectrum density. The separation between the two classes of fatigue (non-fatigue and fatigue) was calculated using the Davies-Bouldin Index (DBI). Results show that higher separability between the fatigue content of the sEMG signal when placed longitudinally, in the same direction as the muscle fibers.

Keywords: array electrodes, biceps brachii, electrode placement, EMG, isometric contractions, muscle fatigue

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Authors: Moon Hee Jung, Dae Seung Kim, Sang-Myung Jung, Gwang Heum Yoon, Hoo Cheol Lee, Hwa Sung Shin

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Scaffolds are an important part to support growth and differentiation of osteoblast for regeneration of injured bone in bone tissue engineering. We utilized tunicate cellulose nanowhisker (CNW) as scaffold and developed complex system that can enhance differentiation of osteoblast by applying mechanical stimulation. CNW, a crystal form of cellulose, has high stiffness with a large surface area and is useful as a biomedical material due to its biodegradability and biocompatibility. In this study, CNW was obtained from tunicate extraction and was confirmed for its adhesion, differentiation, growth of osteoblast without cytotoxicity. In addition, osteoblast was successfully differentiated under mechanical stimulation, followed by calcium dependent signaling. In conclusion, we verified suitability of CNW as scaffold and possibility of bone substitutes.

Keywords: osteoblast, cellulose nanowhisker, CNW, mechanical stimulation, bone tissue engineering, bone substitute

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Authors: Roswati Md. Amin, Nurul Asmera Mudiman, Muhammad Faisal Abd. Rahman, Md-Suffian Idris, Noor Hazwani Mohd Azmi

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Distribution of picophytoplankton from two genera, Synechococcus and Prochlorococcus at the surface water (0.5m) were observed from coastal to offshore area of the southeastern coast of Peninsular Malaysia, for a six day cruise in August 2014 during SouthWest monsoon. The picophytoplankton was divided into two different size fractions (0.7-2.7μm and <0.7 μm) by filtering through GF/D (2.7 μm) and GF/F (0.7 μm) filter papers and counted by using flow cytometer. Synechococcus and Prochlorococcus contribute higher at 0.7-2.7μm size range (ca. 90% and 95%, respectively) compared to <0.7 μm (ca. 10% and 5%, respectively). Synechococcus (>52%) dominated the total picophytoplankton compared to Prochlorococcus (<26%) for both size fractions in southeastern coast of Peninsular Malaysia. Total density (<2.7 μm) of Synechococcus was ranging between 1.72 x104 and 12.57 x104 cells ml-1, while Prochlorococcus varied from 1.50 x104 to 8.62 x104. Both Synechococcus and Prochlorococcus abundance showed a decreasing trend from coastal to offshore.

Keywords: Peninsular Malaysia, prochlorococcus, South China Sea, synechococcus

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Authors: Sanjay Kumar Behera, Kanhu Charan Patra

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A GIS-based method has been applied for the determination of soil erosion and sediment yield in a small watershed in Ong River basin, Odisha, India. The method involves spatial disintegration of the catchment into homogenous grid cells to capture the catchment heterogeneity. The gross soil erosion in each cell was calculated using Universal Soil Loss Equation (USLE) by carefully determining its various parameters. The concept of sediment delivery ratio is used to route surface erosion from each of the discretized cells to the catchment outlet. The process of sediment delivery from grid cells to the catchment outlet is represented by the topographical characteristics of the cells. The effect of DEM resolution on sediment yield is analyzed using two different resolutions of DEM. The spatial discretization of the catchment and derivation of the physical parameters related to erosion in the cell are performed through GIS techniques.

Keywords: DEM, GIS, sediment delivery ratio, sediment yield, soil erosion

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Authors: M. H. Alhajeri, Hamad M. Alhajeri, A. H. Alenezi

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Computational fluid dynamics (CFD) investigation of heat transfer in U-duct with turbulators is presented in this paper. The duct passages used to cool internally the blades in gas turbine. The study is focused in the flow behavior and the Nusselt number (Nu) distributions. The model of the u-duct contains two square legs that are connected by 180* turn. Four turbulators are located in each surface of the leg and distributed in a staggered arrangement. The turbulator height and width are equal to 0.1 of the duct width, and the turbulator height is 0.1 of the distance between the turbulators. The Reynolds number (Re) used in this study is 95000 and the inlet velocity is 10 m/s. It was noticed that, after the flow resettles from the interruptions generated by the first turbulator or the turn, the flow construct two eddies, one large and the other is small after and before the turbulator, respectively. The maximum values of the Nu are found at a distance of approximately one turbulator width w before of the flow reattachment point.

Keywords: computational fluid dynamics, CFD, rib, heat transfer, blade

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Authors: El Hadi Zouaoui, Djamel Nibou, Mohamed Haddouche, Wan Azlina Wan Ab Karim Ghani, Samira Amokrane

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In this study, CH₄ adsorption isotherms on NaX or Faujasite X and exchanged zeolites with Li⁺(LiX), and K⁺(KX) at different temperatures (298, 308, 323 and 353 K) has been investigated, using high pressure (3 MPa (30 bar)) thermo-gravimetric analyser. The experimental results were then validated using several isothermal kinetics models, namely Langmuir, Toth, and Marczewski-Jaroniec, followed by a calculation of the error coefficients between the experimental and theoretical results. It was found that the CH₄ adsorption isotherms are characterized by a strong increase in adsorption at low pressure and a tendency towards a high pressure limit value Qₘₐₓ. The size and position of the exchanged cations, the spherical shape of methane, the specific surface, and the volume of the pores revealed the most important influence parameters for this study. These results revealed that the experimentation and the modeling, well correlated with Marczewski-Jaroniec, Toth, and gave the best results whatever the temperature and the material used.

Keywords: CH₄ adsorption, exchange cations, exchanged zeolite, isotherm study, NaX zeolite

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Authors: Xia Chen, Hua-Quan Yang, Shi-Hua Zhou

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Alkali-active sandstone aggregate was ground by vertical and ball mill into particles with residue over 45 μm less than 12%, and investigations have been launched on particles distribution and characterization of ground sandstone powder, fluidity, heat of hydration, strength as well as hydration products morphology of pastes with incorporation of ground sandstone powder. Results indicated that ground alkali-active sandstone powder with residue over 45 μm less than 8% was easily obtainable, and specific surface area was more sensitive to characterize its fineness with extension of grinding length. Incorporation of sandstone powder resulted in higher water demand and lower strength, advanced hydration of C₃A and C₂S within 3days and refined pore structure. Based on its manufacturing, characteristics and influence on properties of pastes, it was concluded that sandstone powder was a good selection for use in concrete as mineral admixture.

Keywords: concrete, mineral admixture, hydration, structure

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Authors: Pedro Rubio

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Antonio Romero y Andía, was one of the most active and interesting figures in 19th century Spanish music. He was not only an exceptional clarinetist, he was also a publisher, a brilliant oboist, a music critic, and he revitalized Madrid’s musical scene by promoting orchestras and a national opera. In 1849, Romero was appointed Professor of Clarinet at the Conservatory of Madrid. Shortly after, Romero introduced to Spain the Boehm-System clarinet recently appeared in France. However, when initial interest in that system waned, he conceived his own system in 1853. The clarinet was manufactured in Paris by Lefêvre, who registered its first patent in 1862. In 1867 a second version was patented, and a year earlier, in 1866, the Romero clarinet was adopted as an official instrument for teaching the clarinet at the Conservatory of Madrid. The Romero-System clarinet mechanism has incorporated numerous additional devices and several extra keys, its skillful combination in a single instrument represents not only one of the pinnacles in the manufacture of musical instruments of the 19th century, but also an authentic synthesis of knowledge and practice in an era in which woodwind instruments were shaped as we know them today. Through the description and analysis of the data related to the aforementioned historical period, this lecture will try to show a crucial time in the history of all woodwind instruments, a period of technological effervescence in which the Romero-System clarinet emerged. The different stages of conception of the clarinet will be described, as well as its manufacturing and marketing process. Romero played with his clarinet system over twenty-five years. The research has identified the repertoire associated with this instrument whose conclusions will be presented in its case in the Congress.

Keywords: Antonio Romero, clarinet, keywork, 19th century

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Authors: Iris Käppler, Paul Matthäi, Chokri Cherif

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In the scope of application of technical textiles, Non-Crimp Fabrics are increasingly used. In general, NCF exhibit excellent load bearing properties, but caused by the manufacturing process, there are some remaining disadvantages which have to be reduced. Regarding to this, a novel technique of processing NCF was developed substituting the binding-thread by an adhesive. This stitch-free method requires new manufacturing concept as well as new basic methods to prove adhesion of glue at fibres and textiles. To improve adhesion properties and the wettability of carbon-fibres by the adhesive, oxyfluorination was used. The modification of carbon-fibres by oxyfluorination was investigated via scanning electron microscope, X-ray photo electron spectroscopy and single fibre tensiometry. Special tensile tests were developed to determine the maximum force required for detachment.

Keywords: non-crimp fabric, adhesive, stitch-free, high-performance fibre

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Authors: Emre Kara, Metehan Demir, Şura Karakuzu, Kadir Koç, Ahmet F. Geylan, Halil Aykul

Abstract:

While the polymeric foam cored sandwiches have been realized for many years, recently there is a growing and outstanding interest on the use of sandwiches consisting of aluminum foam core because of their some of the distinct mechanical properties such as high bending stiffness, high load carrying and energy absorption capacities. These properties make them very useful in the transportation industry (automotive, aerospace, shipbuilding industry), where the "lightweight design" philosophy and the safety of vehicles are very important aspects. Therefore, in this study, the sandwich panels with aluminum alloy foam core and various types and thicknesses of glass fiber reinforced polymer (GFRP) skins produced via Vacuum Assisted Resin Transfer Molding (VARTM) technique were obtained by using a commercial toughened epoxy based adhesive with two components. The aim of this contribution was the analysis of the bending response of sandwiches with various glass fiber reinforced polymer skins. The three point bending tests were performed on sandwich panels at different values of support span distance using a universal static testing machine in order to clarify the effects of the type and thickness of the GFRP skins in terms of peak load, energy efficiency and absorbed energy values. The GFRP skins were easily bonded to the aluminum alloy foam core under press machine with a very low pressure. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, collapse mechanisms and the influence of the support span length and GFRP skins. The obtained results of the experimental investigation presented that the sandwich with the skin made of thicker S-Glass fabric failed at the highest load and absorbed the highest amount of energy compared to the other sandwich specimens. The increment of the support span distance made the decrease of the peak force and absorbed energy values for each type of panels. The common collapse mechanism of the panels was obtained as core shear failure which was not affected by the skin materials and the support span distance.

Keywords: aluminum foam, collapse mechanisms, light-weight structures, transport application

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Authors: Katsuya Takasaki, Manabu Takao, Toshiaki Setoguchi

Abstract:

Effect of 3-dimensional (3D) blade on the turbine characteristics of Wells turbine for wave energy conversion has been investigated experimentally by model testing under steady flow conditions in the study, in order to improve the peak efficiency and the stall characteristics. The aim of the use of 3D blade is to prevent flow separation on the suction surface near the tip. The chord length is constant with radius and the blade profile changes gradually from mean radius to tip. The proposed blade profiles in the study are NACA0015 from hub to mean radius and NACA0025 at the tip. The performances of Wells turbine with 3D blades has been compared with those of the original Wells turbine, i.e. the turbine with 2-dimensional (2D) blades. As a result, it was concluded that although the peak efficiency of Wells turbine can be improved by the use of the proposed 3D blade, its blade does not overcome the weakness of stalling.

Keywords: fluid machinery, ocean engineering, stall, wave energy conversion, wells turbine

Procedia PDF Downloads 299

Authors: Ali A. Aldosari

Abstract:

Change detection of Earth surface features is extremely important for better understanding of our environment in order to promote better decision making. Al-Jawf is remarkable for its abundant agricultural water where there is fertile agricultural land due largely to underground water. As result, this region has large areas of cultivation of dates, olives and fruits trees as well as other agricultural products such as Alfa Alfa and wheat. However this agricultural area was declined due to the reduction of government supports in the last decade. This reduction was not officially recorded or measured in this region at large scale or governorate level. Remote sensing data are primary sources extensively used for change detection in agriculture applications. This study is applied the technology of GIS and used the Normalized Difference Vegetation Index (NDVI) which can be used to measure and analyze the spatial and temporal changes in the agriculture areas in the Aljouf region.

Keywords: spatial analysis, geographical information system, change detection

Procedia PDF Downloads 398

Authors: Ragy Raafat Gaber Attaalla

Abstract:

Background: We looked at acute poisonings brought on by illegal drugs and pharmaceuticals that influence the nervous system at Assiut University Hospitals. Methods: Between January 2010 and December 2015, we conducted a retrospective examination of patient records from the largest tertiary toxicology referral center in Assiut. We examined the frequency, pattern, and distribution of ages and genders of acute nervous system agent poisoning. Results: 29,083 individuals total—16,657 (57.27%) males and 12,426 (42.73%) females—were included in the current study. Men's and women's median ages were 29 and 26, respectively (p < 0.0001). 10,326 (83.10%) women and 12,071 (72.47%) men under 40 were present (p < 0.001). 44.10% of cases had a history of poisoning, and the majority of cases (69.38% in men and 79.00% in women, p<0.001) were purposeful. Between various age groups and nervous system agents, there were notable variations in the ratios of men and women. The most often used agent for women was alprazolam, whereas methadone was more popular for men. Overall, there was a rising tendency in acute poisoning associated with alcohol and opioids used to treat addiction disorders, but a declining trend with benzodiazepines and antidepressants. Conclusion: Addiction to methadone was widespread, particularly in young males, and the majority of these cases were self-inflicted. Alprazolam and clonazepam poisoning most commonly affect women and males in the 20–29 age range, respectively. Opium was utilized by men over 30 and women over 60. Over half of the deaths were related to illicit narcotics, with opium being the most common. This research could raise awareness and lead to the development of gender- and age-specific local programs for education and prevention.

Keywords: acute poisonings, illegal drugs, pharmaceuticals, nerve system

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