Search results for: turbulent spectrum
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1726

Search results for: turbulent spectrum

1186 Unraveling the Complexities of Competitive Aggressiveness: A Qualitative Exploration in the Oil and Gas Industry

Authors: Salim Al Harthy, Alexandre A. Bachkirov

Abstract:

This study delves into the complexities of competitive aggressiveness in the oil and gas industry, focusing on the characteristics of the identified competitive actions. The current quantitative research on competitive aggressiveness lacks agreement on the connection between antecedents and outcomes, prompting a qualitative investigation. To address this gap, the research utilizes qualitative interviews with CEOs from Oman's oil and gas service industry to explore the dynamics of competitive aggressiveness. Using Noklenain's typology, the study categorizes and analyzes identified actions, shedding light on the spectrum of competitive behaviors within the industry. Notably, actions predominantly fall under the "Bring about" and "Preserve" elements, with a notable absence in the "Forebear" and "Destroy" categories, possibly linked to the study's focus on service-oriented businesses. The study also explores the detectability of actions, revealing that "Bring about" actions are detectable, while those in "Preserve" and "Suppress" are not. This challenges conventional definitions of competitive aggressiveness, suggesting that not all actions are readily detectable despite being considered competitive. The presence of non-detectable actions introduces complexity to measurement methods reliant on visible empirical data. Moreover, the study contends that companies can adopt an aggressive competitive approach without directly challenging rivals. This challenges traditional views and emphasizes the innovative and entrepreneurial aspects of actions not explicitly aimed at competitors. By not revealing strategic intentions, such actions put rivals at a disadvantage, underscoring the need for a nuanced understanding of competitive aggressiveness. In summary, the lack of consensus in existing literature regarding the relationship between antecedents and outcomes in competitive aggressiveness is addressed. The study reveals a spectrum of detectable and undetectable actions, posing challenges in measurement and emphasizing the need for alternative methods to assess undetectable actions in competitive behavior. This research contributes to a more nuanced understanding of competitive aggressiveness, acknowledging the diverse actions shaping a company's strategic positioning in dynamic business environments.

Keywords: competitive aggressiveness, qualitative exploration, noklenain's typology, oil and gas industry

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1185 Sensory Integration for Standing Postural Control Among Children and Adolescents with Autistic Spectrum Disorder Compared with Typically Developing Children and Adolescents

Authors: Eglal Y. Ali, Smita Rao, Anat Lubetzky, Wen Ling

Abstract:

Background: Postural abnormalities, rigidity, clumsiness, and frequent falls are common among children with autism spectrum disorders (ASD). The central nervous system’s ability to process all reliable sensory inputs (weighting) and disregard potentially perturbing sensory input (reweighting) is critical for successfully maintaining standing postural control. This study examined how sensory inputs (visual and somatosensory) are weighted and reweighted to maintain standing postural control in children with ASD compared with typically developing (TD) children. Subjects: Forty (20 (TD) and 20 ASD) children and adolescents participated in this study. The groups were matched for age, weight, and height. Participants had normal somatosensory (no somatosensory hypersensitivity), visual, and vestibular perception. Participants with ASD were categorized with severity level 1 according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and Social Responsiveness Scale. Methods: Using one force platform, the center of pressure (COP) was measured during quiet standing for 30 seconds, 3 times first standing on stable surface with eyes open (Condition 1), followed by randomization of the following 3 conditions: Condition 2 standing on stable surface with eyes closed, (visual input perturbed); Condition 3 standing on compliant foam surface with eyes open, (somatosensory input perturbed); and Condition 4 standing on compliant foam surface with eyes closed, (both visual and somatosensory inputs perturbed). Standing postural control was measured by three outcome measures: COP sway area, COP anterior-posterior (AP), and mediolateral (ML) path length (PL). A repeated measure mixed model Analysis of Variance was conducted to determine whether there was a significant difference between the two groups in the mean of the three outcome measures across the four conditions. Results: According to all three outcome measures, both groups showed a gradual increase in postural sway from condition 1 to condition 4. However, TD participants showed a larger postural sway than those with ASD. There was a significant main effect of condition on three outcome measures (p< 0.05). Only the COP AP PL showed a significant main effect of the group (p<0.05) and a significant group by condition interaction (p<0.05). In COP AP PL, TD participants showed a significant difference between condition 2 and the baseline (p<0.05), whereas the ASD group did not. This suggests that the ASD group did not weight visual input as much as the TD group. A significant difference between conditions for the ASD group was seen only when participants stood on foam regardless of the visual condition, suggesting that the ASD group relied more on the somatosensory inputs to maintain the standing postural control. Furthermore, the ASD group exhibited significantly smaller postural sway compared with TD participants during standing on the stable surface, whereas the postural sway of the ASD group was close to that of the TD group on foam. Conclusion: These results suggest that participants with high functioning ASD (level 1, no somatosensory hypersensitivity in ankles and feet) over-rely on somatosensory inputs and use a stiffening strategy for standing postural control. This deviation in the reweighting mechanism might explain the postural abnormalities mentioned above among children with ASD.

Keywords: autism spectrum disorders, postural sway, sensory weighting and reweighting, standing postural control

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1184 Sensory Weighting and Reweighting for Standing Postural Control among Children and Adolescents with Autistic Spectrum Disorder Compared with Typically Developing Children and Adolescents

Authors: Eglal Y. Ali, Smita Rao, Anat Lubetzky, Wen Ling

Abstract:

Background: Postural abnormalities, rigidity, clumsiness, and frequent falls are common among children with autism spectrum disorders (ASD). The central nervous system’s ability to process all reliable sensory inputs (weighting) and disregard potentially perturbing sensory input (reweighting) is critical for successfully maintaining standing postural control. This study examined how sensory inputs (visual and somatosensory) are weighted and reweighted to maintain standing postural control in children with ASD compared with typically developing (TD) children. Subjects: Forty (20 (TD) and 20 ASD) children and adolescents participated in this study. The groups were matched for age, weight, and height. Participants had normal somatosensory (no somatosensory hypersensitivity), visual, and vestibular perception. Participants with ASD were categorized with severity level 1 according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and Social Responsiveness Scale. Methods: Using one force platform, the center of pressure (COP) was measured during quiet standing for 30 seconds, 3 times first standing on stable surface with eyes open (Condition 1), followed by randomization of the following 3 conditions: Condition 2 standing on stable surface with eyes closed, (visual input perturbed); Condition 3 standing on a compliant foam surface with eyes open, (somatosensory input perturbed); and Condition 4 standing on a compliant foam surface with eyes closed, (both visual and somatosensory inputs perturbed). Standing postural control was measured by three outcome measures: COP sway area, COP anterior-posterior (AP), and mediolateral (ML) path length (PL). A repeated measure mixed model analysis of variance was conducted to determine whether there was a significant difference between the two groups in the mean of the three outcome measures across the four conditions. Results: According to all three outcome measures, both groups showed a gradual increase in postural sway from condition 1 to condition 4. However, TD participants showed a larger postural sway than those with ASD. There was a significant main effect of the condition on three outcome measures (p< 0.05). Only the COP AP PL showed a significant main effect of the group (p<0.05) and a significant group by condition interaction (p<0.05). In COP AP PL, TD participants showed a significant difference between condition 2 and the baseline (p<0.05), whereas the ASD group did not. This suggests that the ASD group did not weigh visual input as much as the TD group. A significant difference between conditions for the ASD group was seen only when participants stood on foam regardless of the visual condition, suggesting that the ASD group relied more on the somatosensory inputs to maintain the standing postural control. Furthermore, the ASD group exhibited significantly smaller postural sway compared with TD participants during standing on a stable surface, whereas the postural sway of the ASD group was close to that of the TD group on foam. Conclusion: These results suggest that participants with high-functioning ASD (level 1, no somatosensory hypersensitivity in ankles and feet) over-rely on somatosensory inputs and use a stiffening strategy for standing postural control. This deviation in the reweighting mechanism might explain the postural abnormalities mentioned above among children with ASD.

Keywords: autism spectrum disorders, postural sway, sensory weighting and reweighting, standing postural control

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1183 Numerical Analysis of Roughness Effect on Mini and Microchannels: Hydrodynamics and Heat Transfer

Authors: El-Ghalia Filali, Cherif Gadouche, Mohamed Tahar

Abstract:

A three-dimensional numerical simulation of flow through mini and microchannels with designed roughness is conducted here. The effect of the roughness height (surface roughness), geometry, Reynolds number on the friction factor and the Nusselt number is investigated. The study is carried out by employing CFD software, CFX. Our work focuses on a water flow inside a circular mini-channel of 1 mm and microchannels of 500 and 100 μm in diameter. The speed entry varies from 0.1 m/s to 20 m/s. The general trend can be observed that bigger sizes of roughness element lead to higher flow resistance. It is found that the friction factor increases in a nonlinear fashion with the increase in obstruction height. Particularly, the effect of roughness can no longer be ignored at relative roughness height higher than 3%. A significant increase in Poiseuille number is detected for all configurations considered. The same observation can be done for Nusselt number. The transition zone between laminar and turbulent flow depends on the channel diameter.

Keywords: hydrodynamics, heat transfer, minichannel, microchannel, roughness

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1182 Study of the Relationship between the Roughness Configuration of Channel Bottom and the Creation of Vortices at the Rough Area: Numerical Modelling

Authors: Youb Said, Fourar Ali

Abstract:

To describe the influence of bottom roughness on the free surface flows by numerical modeling, a two-dimensional model was developed. The equations of continuity and momentum (Naviers Stokes equations) are solved by the finite volume method. We considered a turbulent flow in an open channel with a bottom roughness. For our simulations, the K-ε model was used. After setting the initial and boundary conditions and solve the equations set, we were able to achieve the following results: vortex forming in the hollow causing substantial energy dissipation in the obstacle areas that form the bottom roughness. The comparison of our results with experimental ones shows a good agreement in terms of the results in the rough area. However, in other areas, differences were more or less important. These differences are in areas far from the bottom, especially the free surface area just after the bottom. These disagreements are probably due to experimental constants used by the k-ε model.

Keywords: modeling, free surface flow, turbulence, bottom roughness, finite volume, K-ε model, energy dissipation

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1181 Communication Barriers and Challenges for Accessing Autism Care: Conventional Versus Alternative Medicine

Authors: M. D. Antoine

Abstract:

Despite the widespread use of complementary and alternative medicine (CAM) for autistic children, little is known about the communication flow between the different parties involved in autism care (e.g., parents/caregivers, conventional providers, alternative practitioners). This study aimed to describe how communication occurs through the first year following an autism spectrum disorder (ASD) diagnosis to identify challenges and potential barriers to communication within the healthcare system in Ottawa, Canada. From an ecological perspective, we collected qualitative data through 12 semi-structured interviews with six parents/caregivers, three conventional providers (e.g., family doctor, neurodevelopmental pediatrician, psychologist), and three alternative practitioners (e.g., naturopath, occupational therapist, speech and language pathologist) operating in Ottawa. We interpreted the data using thematic analysis. Findings revealed communication challenges between the parents/caregivers and conventional providers while they experience better communication flow with fewer challenges in alternative care settings. However, parents/caregivers are the only links between the health professionals of both streams. From the five contexts examined: organizational, interpersonal, media, cultural, and political-legal, we found four themes (provider knowledge, care integration, flexible care, and time constraints) underlining specific barriers to communication flow between the parties involved in the care of autistic children. The increasing interest in alternative medicine is forcing changes in the healthcare system. Communications occur outside the norms making openings for better communication and information-sharing increasingly essential. Within the identified themes in the current study, the necessity for better communication between all parties involved in the care of autistic children is evident. More ASD and CAM-related training for providers would support effective parent/caregiver-provider communication. The findings of the current study contribute to a better understanding of the role of communication in the care management of autism, which has implications for effective autism care.

Keywords: alternative medicine, autism care management, autism spectrum disorder, conventional medicine, parent-provider communication

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1180 Europium Chelates as a Platform for Biosensing

Authors: Eiman A. Al-Enezi, Gin Jose, Sikha Saha, Paul Millner

Abstract:

Rare earth nanotechnology has gained a considerable amount of interest in the field of biosensing due to the unique luminescence properties of lanthanides. Chelating rare earth ions plays a significant role in biological labelling applications including medical diagnostics, due to their different excitation and emission wavelengths, variety of their spectral properties, sharp emission peaks and long fluorescence lifetimes. We aimed to develop a platform for biosensors based on Europium (Eu³⁺) chelates against biomarkers of cardiac injury (heart-type fatty acid binding protein; H-FABP3) and stroke (glial fibrillary acidic protein; GFAP). Additional novelty in this project is the use of synthetic binding proteins (Affimers), which could offer an excellent alternative targeting strategy to the existing antibodies. Anti-GFAP and anti-HFABP3 Affimer binders were modified to increase the number of carboxy functionalities. Europium nitrate then incubated with the modified Affimer. The luminescence characteristics of the Eu³⁺ complex with modified Affimers and antibodies against anti-GFAP and anti-HFABP3 were measured against different concentrations of the respective analytes on excitation wavelength of 395nm. Bovine serum albumin (BSA) was used as a control against the IgG/Affimer Eu³⁺ complexes. The emission spectrum of Eu³⁺ complex resulted in 5 emission peaks ranging between 550-750 nm with the highest intensity peaks were at 592 and 698 nm. The fluorescence intensity of Eu³⁺ chelates with the modified Affimer or antibodies increased significantly by 4-7 folder compared to the emission spectrum of Eu³⁺ complex. The fluorescence intensity of the Affimer complex was quenched proportionally with increased analyte concentration, but this did not occur with antibody complex. In contrast, the fluorescence intensity for Eu³⁺ complex increased slightly against increased concentration of BSA. These data demonstrate that modified Affimers Eu³⁺ complexes can function as nanobiosensors with potential diagnostic and analytical applications.

Keywords: lanthanides, europium, chelates, biosensors

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1179 Design, Synthesis and in-vitro Antitumor Evaluation of Some Novel Substituted Quinazoline Derivatives

Authors: Adel S. El-Azab, Alaa A. M. Abdel-Aziz, Ibrahim A. Al-Suwaidan, Amer M. Alanazi

Abstract:

A novel series of 2,3,6-trisubstitute quinazolinone were designed, synthesized, and evaluated for their in-vitro antitumor activity. 3 (Benzylideneamino)-6-chloro-2-p-tolylquinazolin-4(3H)-One, 2-[(4-oxo-3-phenethyl-3,4-dihydroquinazolin-2-yl)thio]-N-(3,4;5-trimethoxyphenyl) acetamide and 3-(3-benzyl-6-methyl-4-oxo-3, 4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl) propanamide have shown amazing broad spectrum antitumor activity with mean GI50; 15.8, 3.16, and 7.4 μM respectively compared to known Quinazoline Derivatives antitumor drug 5-FU mean GI50=22.6 μM.

Keywords: quinazoline derivatives, in vitro antitumor, synthesis, 5-FU, NCI

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1178 Numerical Simulation of Structured Roughness Effect on Fluid Flow Characteristics and Heat Transfer in Minichannels

Authors: R. Chouatah, E. G. Filali, B. Zouzou

Abstract:

It has been well established that there are no differences between microscale and macroscale flows of incompressible liquids. However, surface roughness has been known to impact the transport phenomena. The effect of structured roughness on the dynamics and heat transfer of water flowing through minichannel was numerically investigated in this study. Our study consists in characterizing the dynamic field and heat transfer aspect of a flow in circular minichannel equipped with structured roughness using CFD software, CFX. The study is performed to understand the effect of various roughness elements (rectangular, triangular), roughness height and roughness pitch on the friction factor and heat transfer coefficient. Our work focuses on a water flow inside a circular mini-channel of 1 mm in diameter and 10 cm in length. The speed entry into the mini-channel varies from 0.1 m/s to 25 m/s. The wall of the mini-channel is submitted to a constant heat flux; q=100,000 W/m². The simulations results are compared to those obtained with smooth minichannel and the existing experimental and numerical results in the literature.

Keywords: heat transfer, laminar and turbulent flow, minichannel, structured roughness

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1177 MR Imaging Spectrum of Intracranial Infections: An Experience of 100 Cases in a Tertiary Hospital in Northern India

Authors: Avik Banerjee, Kavita Saggar

Abstract:

Infections of the nervous system and adjacent structures are often life-threatening conditions. Despite the recent advances in neuroimaging evaluation, the diagnosis of unclear infectious CNS disease remains a challenge. Our aim is to evaluate the typical and atypical neuro-imaging features of the various routinely encountered CNS infected patients so as to form guidelines for their imaging recognition and differentiation from tumoral, vascular and other entities that warrant a different line of therapy.

Keywords: central nervous system (CNS), Cerebro Spinal Fluid (Csf), Creutzfeldt Jakob Disease (CJD), progressive multifocal leukoencephalopathy (PML)

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1176 Principal Component Analysis Combined Machine Learning Techniques on Pharmaceutical Samples by Laser Induced Breakdown Spectroscopy

Authors: Kemal Efe Eseller, Göktuğ Yazici

Abstract:

Laser-induced breakdown spectroscopy (LIBS) is a rapid optical atomic emission spectroscopy which is used for material identification and analysis with the advantages of in-situ analysis, elimination of intensive sample preparation, and micro-destructive properties for the material to be tested. LIBS delivers short pulses of laser beams onto the material in order to create plasma by excitation of the material to a certain threshold. The plasma characteristics, which consist of wavelength value and intensity amplitude, depends on the material and the experiment’s environment. In the present work, medicine samples’ spectrum profiles were obtained via LIBS. Medicine samples’ datasets include two different concentrations for both paracetamol based medicines, namely Aferin and Parafon. The spectrum data of the samples were preprocessed via filling outliers based on quartiles, smoothing spectra to eliminate noise and normalizing both wavelength and intensity axis. Statistical information was obtained and principal component analysis (PCA) was incorporated to both the preprocessed and raw datasets. The machine learning models were set based on two different train-test splits, which were 70% training – 30% test and 80% training – 20% test. Cross-validation was preferred to protect the models against overfitting; thus the sample amount is small. The machine learning results of preprocessed and raw datasets were subjected to comparison for both splits. This is the first time that all supervised machine learning classification algorithms; consisting of Decision Trees, Discriminant, naïve Bayes, Support Vector Machines (SVM), k-NN(k-Nearest Neighbor) Ensemble Learning and Neural Network algorithms; were incorporated to LIBS data of paracetamol based pharmaceutical samples, and their different concentrations on preprocessed and raw dataset in order to observe the effect of preprocessing.

Keywords: machine learning, laser-induced breakdown spectroscopy, medicines, principal component analysis, preprocessing

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1175 Thermal Performance Analysis of Nanofluids in a Concetric Heat Exchanger Equipped with Turbulators

Authors: Feyza Eda Akyurek, Bayram Sahin, Kadir Gelis, Eyuphan Manay, Murat Ceylan

Abstract:

Turbulent forced convection heat transfer and pressure drop characteristics of Al2O3–water nanofluid flowing through a concentric tube heat exchanger with and without coiled wire turbulators were studied experimentally. The experiments were conducted in the Reynolds number ranging from 4000 to 20000, particle volume concentrations of 0.8 vol.% and 1.6 vol.%. Two turbulators with the pitches of 25 mm and 39 mm were used. The results of nanofluids indicated that average Nusselt number increased much more with increasing Reynolds number compared to that of pure water. Thermal conductivity enhancement by the nanofluids resulted in heat transfer enhancement. Once the pressure drop of the alumina/water nanofluid was analyzed, it was nearly equal to that of pure water at the same Reynolds number range. It was concluded that nanofluids with the volume fractions of 0.8 and 1.6 did not have a significant effect on pressure drop change. However, the use of wire coils in heat exchanger enhanced heat transfer as well as the pressure drop.

Keywords: turbulators, heat exchanger, nanofluids, heat transfer enhancement

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1174 Detection of Autism Spectrum Disorders in Children Aged 4-6 Years by Municipal Maternal and Child Health Physicians: An Educational Intervention Study

Authors: M. Van 'T Hof, R. V. Pasma, J. T. Bailly, H. W. Hoek, W. A. Ester

Abstract:

Background: The transition into primary school can be challenging for children with an autism spectrum disorder (ASD). Due to the new demands that are made to children in this period, their limitations in social functioning and school achievements may manifest and appear faster. Detection of possible ASD signals mainly takes place by parents, teachers and during obligatory municipal maternal and child health centre visits. Physicians of municipal maternal and child health centres have limited education and instruments to detect ASD. Further education on detecting ASD is needed to optimally equip these doctors for this task. Most research aims to increase the early detection of ASD in children aged 0-3 years and shows positive results. However, there is a lack of research on educational interventions to detect ASD in children aged 4-6 years by municipal maternal and child health physicians. Aim: The aim of this study is to explore the effect of the online educational intervention: Detection of ASD in children aged 4-6 years for municipal maternal and child health physicians. This educational intervention is developed within The Reach-Aut Academic Centre for Autism; Transitions in education, and will be available throughout The Netherlands. Methods: Ninety-two participants will follow the educational intervention: Detection of ASD in children aged 4-6 years for municipal maternal and child health centre physicians. The educational intervention consists of three, one and a half hour sessions, which are offered through an online interactive classroom. The focus and content of the course has been developed in collaboration with three groups of stakeholders; autism scientists, clinical practitioners (municipal maternal and child health doctors and ASD experts) and parents of children with ASD. The primary outcome measure is knowledge about ASD: signals, early detection, communication with parents and referrals. The secondary outcome measures are the number of ASD related referrals, the attitude towards the mentally ill (CAMI), perceived competency about ASD knowledge and detection skills, and satisfaction about the educational intervention. Results and Conclusion: The study started in January 2016 and data collection will end mid 2017.

Keywords: ASD, child, detection, educational intervention, physicians

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1173 Photoprotective and Antigenotoxic Effects of a Mixture of Posoqueria latifolia Flower Extract and Kaempferol Against Ultraviolet B Radiation

Authors: Silvia Ximena Barrios, Diego Armando Villamizar Mantilla, Raquel Elvira Ocazionez, , Elena E. Stashenko, María Pilar Vinardell, Jorge Luis Fuentes

Abstract:

Introduction: Skin overexposure to solar radiation has been a serious public health concern, because of its potential carcinogenicity. Therefore, preventive protection strategies using photoprotective agents are critical to counteract the harmful effect of solar radiation. Plants may be a source of photoprotective compounds that inhibit cellular mutations involved in skin cancer initiation. This work evaluated the photoprotective and antigenotoxic effects against ultraviolet B (UVB) radiation of a mixture of Posoqueria latifolia flower extract and Kaempferol (MixPoKa). Methods: The photoprotective efficacy of MixPoka (Posoqueria latifolia flower extract 250 μg/ml and Kaempferol 349.5 μM) was evaluated using in vitro indices such as sun protection factor SPFᵢₙ ᵥᵢₜᵣₒ and critical wavelength (λc). The MixPoKa photostability (Eff) at human minimal erythema doses (MED), according to the Fitzpatrick skin scale, was also estimated. Cytotoxicity and genotoxicity/antigenotoxicity were studied in MRC5 human fibroblasts using the trypan blue exclusion and Comet assays, respectively. Kinetics of the genetic damage repair post irradiation in the presence and absence of the MixPoka, was also evaluated. Results: The MixPoka -UV absorbance spectrum was high across the spectral bands between 200 and 400 nm. The UVB photoprotection efficacy of MixPoka was high (SPFᵢₙ ᵥᵢₜᵣₒ = 25.70 ± 0.06), showed wide photoprotection spectrum (λc = 380 ± 0), and resulted photostable (Eff = 92.3–100.0%). The MixPoka was neither cytotoxic nor genotoxic in MRC5 human fibroblasts; but presented significant antigenotoxic effect against UVB radiation. Additionally, MixPoka stimulate DNA repair post-irradiation. The potential of this phytochemical mixture as sunscreen ingredients was discussed. Conclusion: MixPoka showed a significant antigenotoxic effect against UVB radiation and stimulated DNA repair after irradiation. MixPoka could be used as an ingredient in a sunscreen cream.

Keywords: flower extract, photoprotection, antigenotoxicity, cytotoxicity, genotoxicit

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1172 Numerical Modeling of Flow in USBR II Stilling Basin with End Adverse Slope

Authors: Hamidreza Babaali, Alireza Mojtahedi, Nasim Soori, Saba Soori

Abstract:

Hydraulic jump is one of the effective ways of energy dissipation in stilling basins that the ‎energy is highly dissipated by jumping. Adverse slope surface at the end stilling basin is ‎caused to increase energy dissipation and stability of the hydraulic jump. In this study, the adverse slope ‎has been added to end of United States Bureau of Reclamation (USBR) II stilling basin in hydraulic model of Nazloochay dam with scale 1:40, and flow simulated into stilling basin using Flow-3D ‎software. The numerical model is verified by experimental data of water depth in ‎stilling basin. Then, the parameters of water level profile, Froude Number, pressure, air ‎entrainment and turbulent dissipation investigated for discharging 300 m3/s using K-Ɛ and Re-Normalization Group (RNG) turbulence ‎models. The results showed a good agreement between numerical and experimental model‎ as ‎numerical model can be used to optimize of stilling basins.‎

Keywords: experimental and numerical modelling, end adverse slope, flow ‎parameters, USBR II stilling basin

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1171 Seismic Analysis of Vertical Expansion Hybrid Structure by Response Spectrum Method Concern with Disaster Management and Solving the Problems of Urbanization

Authors: Gautam, Gurcharan Singh, Mandeep Kaur, Yogesh Aggarwal, Sanjeev Naval

Abstract:

The present ground reality scenario of suffering of humanity shows the evidence of failure to take wrong decisions to shape the civilization with Irresponsibilities in the history. A strong positive will of right responsibilities make the right civilization structure which affects itself and the whole world. Present suffering of humanity shows and reflect the failure of past decisions taken to shape the true culture with right social structure of society, due to unplanned system of Indian civilization and its rapid disaster of population make the failure to face all kind of problems which make the society sufferer. Our India is still suffering from disaster like earthquake, floods, droughts, tsunamis etc. and we face the uncountable disaster of deaths from the beginning of humanity at the present time. In this research paper our focus is to make a Disaster Resistance Structure having the solution of dense populated urban cities area by high vertical expansion HYBRID STRUCTURE. Our efforts are to analyse the Reinforced Concrete Hybrid Structure at different seismic zones, these concrete frames were analyzed using the response spectrum method to calculate and compare the different seismic displacement and drift. Seismic analysis by this method generally is based on dynamic analysis of building. Analysis results shows that the Reinforced Concrete Building at seismic Zone V having maximum peak story shear, base shear, drift and node displacement as compare to the analytical results of Reinforced Concrete Building at seismic Zone III and Zone IV. This analysis results indicating to focus on structural drawings strictly at construction site to make a HYBRID STRUCTURE. The study case is deal with the 10 story height of a vertical expansion Hybrid frame structure at different zones i.e. zone III, zone IV and zone V having the column 0.45x0.36mt and beam 0.6x0.36mt. with total height of 30mt, to make the structure more stable bracing techniques shell be applied like mage bracing and V shape bracing. If this kind of efforts or structure drawings are followed by the builders and contractors then we save the lives during earthquake disaster at Bhuj (Gujarat State, India) on 26th January, 2001 which resulted in more than 19,000 deaths. This kind of Disaster Resistance Structure having the capabilities to solve the problems of densely populated area of cities by the utilization of area in vertical expansion hybrid structure. We request to Government of India to make new plans and implementing it to save the lives from future disasters instead of unnecessary wants of development plans like Bullet Trains.

Keywords: history, irresponsibilities, unplanned social structure, humanity, hybrid structure, response spectrum analysis, DRIFT, and NODE displacement

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1170 Industrial Revolution: Army Production

Authors: M. Şimşek

Abstract:

Additive manufacturing (AM) or generally known as three dimensional (3D) printing provides great opportunities for both civilian and military applications by which 3D has become the biggest nominee of breakthrough of 21th century. When properly used, it has a wide spectrum of applications that make production easier and more profitable. Considering the advantages of AM, every firm has an intention of catching up with this new trend. As well as reducing costs and thus increasing benefits, 3D printing provides opportunities for national armies by reducing maintenance and repair time and increasing operational readiness.

Keywords: additive manufacturing, operational cost, operational readiness, supply chain, three dimensional printing

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1169 Calibration of Mini TEPC and Measurement of Lineal Energy in a Mixed Radiation Field Produced by Neutrons

Authors: I. C. Cho, W. H. Wen, H. Y. Tsai, T. C. Chao, C. J. Tung

Abstract:

Tissue-equivalent proportional counter (TEPC) is a useful instrument used to measure radiation single-event energy depositions in a subcellular target volume. The quantity of measurements is the microdosimetric lineal energy, which determines the relative biological effectiveness, RBE, for radiation therapy or the radiation-weighting factor, WR, for radiation protection. TEPC is generally used in a mixed radiation field, where each component radiation has its own RBE or WR value. To reduce the pile-up effect during radiotherapy measurements, a miniature TEPC (mini TEPC) with cavity size in the order of 1 mm may be required. In the present work, a homemade mini TEPC with a cylindrical cavity of 1 mm in both the diameter and the height was constructed to measure the lineal energy spectrum of a mixed radiation field with high- and low-LET radiations. Instead of using external radiation beams to penetrate the detector wall, mixed radiation fields were produced by the interactions of neutrons with TEPC walls that contained small plugs of different materials, i.e. Li, B, A150, Cd and N. In all measurements, mini TEPC was placed at the beam port of the Tsing Hua Open-pool Reactor (THOR). Measurements were performed using the propane-based tissue-equivalent gas mixture, i.e. 55% C3H8, 39.6% CO2 and 5.4% N2 by partial pressures. The gas pressure of 422 torr was applied for the simulation of a 1 m diameter biological site. The calibration of mini TEPC was performed using two marking points in the lineal energy spectrum, i.e. proton edge and electron edge. Measured spectra revealed high lineal energy (> 100 keV/m) peaks due to neutron-capture products, medium lineal energy (10 – 100 keV/m) peaks from hydrogen-recoil protons, and low lineal energy (< 10 keV/m) peaks of reactor photons. For cases of Li and B plugs, the high lineal energy peaks were quite prominent. The medium lineal energy peaks were in the decreasing order of Li, Cd, N, A150, and B. The low lineal energy peaks were smaller compared to other peaks. This study demonstrated that internally produced mixed radiations from the interactions of neutrons with different plugs in the TEPC wall provided a useful approach for TEPC measurements of lineal energies.

Keywords: TEPC, lineal energy, microdosimetry, radiation quality

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1168 Effect of Submerged Water Jet's Cross Section Shapes on Mixing Length

Authors: Mohsen Solimani Babarsad, Mohammad Rastgoo, Payam Taheri

Abstract:

One of the important applications of hydraulic jets is used for discharge industrial, agricultural and urban wastewater into the rivers or other ambient water to reduce negative effects of pollutant water. Submerged jets due to turbulent condition can mix large amount of dense pollutant water with ambient flow. This study is conducted to investigate the distribution and length of the mixing zone in hydraulic jet's flow field with change in cross section shapes of nozzle. Toward this end, three shapes of cross section (square, circle and rectangular) and three saline densities current with different concentration are considered in a flume with 600 cm as long, 100 cm as high and 150 cm in width. Various discharges were used to evaluate mixing length for a wide range of densimetric Froude numbers, Frd, from 100 to 550 that is defined at the nozzle. Consequently, the circular nozzle, in comparison with other sections, has a densimetric Froude number 11% higher than square nozzle and 26% higher than rectangular nozzle.

Keywords: hydraulic jet, mixing zone, densimetric Froude number, nozzle

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1167 Assessment of Modern RANS Models for the C3X Vane Film Cooling Prediction

Authors: Mikhail Gritskevich, Sebastian Hohenstein

Abstract:

The paper presents the results of a detailed assessment of several modern Reynolds Averaged Navier-Stokes (RANS) turbulence models for prediction of C3X vane film cooling at various injection regimes. Three models are considered, namely the Shear Stress Transport (SST) model, the modification of the SST model accounting for the streamlines curvature (SST-CC), and the Explicit Algebraic Reynolds Stress Model (EARSM). It is shown that all the considered models face with a problem in prediction of the adiabatic effectiveness in the vicinity of the cooling holes; however, accounting for the Reynolds stress anisotropy within the EARSM model noticeably increases the solution accuracy. On the other hand, further downstream all the models provide a reasonable agreement with the experimental data for the adiabatic effectiveness and among the considered models the most accurate results are obtained with the use EARMS.

Keywords: discrete holes film cooling, Reynolds Averaged Navier-Stokes (RANS), Reynolds stress tensor anisotropy, turbulent heat transfer

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1166 Numerical Study on the Effect of Obstacle Structure on Two-Phase Detonation Initiation

Authors: Ding Yu, Ge Yang, Wang Hong-Tao

Abstract:

Aiming at the detonation performance and detonation wave propagation distance of liquid fuel detonation engine, the kerosene/oxygen-enriched air mixture is chosen as the research object; its detonation initiation and detonation wave propagation process by mild energy input are numerically studied by using Euler-Lagrange method in the present study. The effects of a semicircular obstacle, rectangular obstacle, and triangular obstacle on the detonation characteristic parameters in the detonation tube are compared and analyzed, and the effect of the angle between obstacle and flame propagation direction on flame propagation characteristics and detonation process when the blocking ratio is constant are studied. The results show that the flame propagation velocity decreases with the increase of the angle in the range of 0-90°, and when the angle is 0° which corresponds to the semicircle obstacle gets the highest detonation wave propagation velocity. With the increase of the angle in the range of 0-90°, DDT (Deflagration to detonation transition) distance decreases first and then increases.

Keywords: deflagration to detonation transition, numerical simulation, obstacle structure, turbulent flame

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1165 Examining Influence of The Ultrasonic Power and Frequency on Microbubbles Dynamics Using Real-Time Visualization of Synchrotron X-Ray Imaging: Application to Membrane Fouling Control

Authors: Masoume Ehsani, Ning Zhu, Huu Doan, Ali Lohi, Amira Abdelrasoul

Abstract:

Membrane fouling poses severe challenges in membrane-based wastewater treatment applications. Ultrasound (US) has been considered an effective fouling remediation technique in filtration processes. Bubble cavitation in the liquid medium results from the alternating rarefaction and compression cycles during the US irradiation at sufficiently high acoustic pressure. Cavitation microbubbles generated under US irradiation can cause eddy current and turbulent flow within the medium by either oscillating or discharging energy to the system through microbubble explosion. Turbulent flow regime and shear forces created close to the membrane surface cause disturbing the cake layer and dislodging the foulants, which in turn improve the cleaning efficiency and filtration performance. Therefore, the number, size, velocity, and oscillation pattern of the microbubbles created in the liquid medium play a crucial role in foulant detachment and permeate flux recovery. The goal of the current study is to gain in depth understanding of the influence of the US power intensity and frequency on the microbubble dynamics and its characteristics generated under US irradiation. In comparison with other imaging techniques, the synchrotron in-line Phase Contrast Imaging technique at the Canadian Light Source (CLS) allows in-situ observation and real-time visualization of microbubble dynamics. At CLS biomedical imaging and therapy (BMIT) polychromatic beamline, the effective parameters were optimized to enhance the contrast gas/liquid interface for the accuracy of the qualitative and quantitative analysis of bubble cavitation within the system. With the high flux of photons and the high-speed camera, a typical high projection speed was achieved; and each projection of microbubbles in water was captured in 0.5 ms. ImageJ software was used for post-processing the raw images for the detailed quantitative analyses of microbubbles. The imaging has been performed under the US power intensity levels of 50 W, 60 W, and 100 W, in addition to the US frequency levels of 20 kHz, 28 kHz, and 40 kHz. For the duration of 2 seconds of imaging, the effect of the US power and frequency on the average number, size, and fraction of the area occupied by bubbles were analyzed. Microbubbles’ dynamics in terms of their velocity in water was also investigated. For the US power increase of 50 W to 100 W, the average bubble number and the average bubble diameter were increased from 746 to 880 and from 36.7 µm to 48.4 µm, respectively. In terms of the influence of US frequency, a fewer number of bubbles were created at 20 kHz (average of 176 bubbles rather than 808 bubbles at 40 kHz), while the average bubble size was significantly larger than that of 40 kHz (almost seven times). The majority of bubbles were captured close to the membrane surface in the filtration unit. According to the study observations, membrane cleaning efficiency is expected to be improved at higher US power and lower US frequency due to the higher energy release to the system by increasing the number of bubbles or growing their size during oscillation (optimum condition is expected to be at 20 kHz and 100 W).

Keywords: bubble dynamics, cavitational bubbles, membrane fouling, ultrasonic cleaning

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1164 A Numerical Study on the Flow in a Pipe with Perforated Plates

Authors: Myeong Hee Jeong, Man Young Kim

Abstract:

The use of perforated plate and tubes is common in applications such as vehicle exhaust silencers, attenuators in air moving ducts and duct linings in jet engines. Also, perforated plate flow conditioners designed to improve flow distribution upstream of an orifice plate flow meter typically have 50–60% free area but these generally employ a non-uniform distribution of holes of several sizes to encourage the formation of a fully developed pipe flow velocity distribution. In this study, therefore, numerical investigations on the flow characteristics with the various perforated plates have been performed and then compared to the case without a perforated plate. Three different models are adopted such as a flat perforated plate, a convex perforated plate in the direction of the inlet, and a convex perforated plate in the direction of the outlet. Simulation results show that the pressure drop with and without perforated plates are similar each other. However, it can be found that that the different shaped perforated plates influence the velocity contour, flow uniformity index, and location of the fully developed fluid flow. These results can be used as a practical guide to the best design of pipe with the perforated plate.

Keywords: perforated plate, flow uniformity, pipe turbulent flow, CFD (Computational Fluid Dynamics)

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1163 Numerical Analysis of Various V- rib Cross-section to Optimize Thermal Performance of the Rocket Engine

Authors: Hisham Elmouazen, Xiaobing Zhang

Abstract:

In regenerative-cooled rocket engines, understanding the coolant behaviour within cooling channels is essential to enhance engine performance and maintain chamber walls at low temperatures. However, modelling and testing the rocket engine's cooling channels is challenging due to the high temperature of the chamber walls, supercritical flow, and high Reynolds number. Therefore, a numerical analysis of five different V-rib cross-sections to optimize rocket engine cooling channels' performance is developed and validated in this work. Three-dimensional CFD simulations are employed by the Shear Stress Transport (k- ω) turbulent model at Reynolds number 42,500. The study findings illustrate that the V-ribbed channel performance is optimized by 59.5% relative to the plain/flat channel. Additionally, the chamber wall temperature is decreased to 726.4 K, and the right-angle trapezoidal V-rib (Case 4) improves thermal augmentation up to 74.3 % with a slightly high friction factor.

Keywords: computational fluid dynamics CFD, regenerative-cooled system, thermal performance, V-rib cross-sections

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1162 Language Skills in the Emergent Literacy of Spanish-Speaking Children with Autism Spectrum Disorders

Authors: Adriana Salgado, Sandra Castaneda, Ivan Perez

Abstract:

Learning to read and write is a complex process involving several cognitive skills, contextual, and cultural environments. The basis of this development is linguistic skills, such as the ability to name and understand vocabulary, retell a story, phonological awareness, letter knowledge, among others. In children with autism spectrum disorder (ASD), one of the main concerns is related to language disorders. Nevertheless, most of the children with ASD are able to decode written information but have difficulties in reading comprehension. The research of these processes in the Spanish-speaking population is limited. However, the increasing prevalence of this diagnosis (1 in 115 children) in Mexico has implications at different levels. Educational research is an important area of interest in ASD children, such as emergent literacy. Reading and writing expand the possibilities of academic, cultural, and social information access. Taking this information into account, the objective of this research was to identify the relationship between language skills, alphabet knowledge, phonological awareness, and early reading and writing in ASD Spanish-speaking children. The method used for this research was based on tasks that were selected, adapted and in some cases designed to measure initial reading and writing, as well as language skills (naming, receptive vocabulary, and narrative skills), phonological awareness (similar phonological word pairs, beginning sound awareness and spelling) and letter knowledge, in a sample of 45 children (38 boys and 7 girls) with prior diagnosis of ASD. Descriptive analyses, as well as bivariate correlations, cluster analysis, and canonical correspondence, were obtained for the data results. Results showed that variability was large; however, it was possible to characterize the sample in low, medium, and high score groups regarding children performance. The low score group (46.7% of the sample), had a null or deficient performance in language skills and phonological awareness, some could identify up to five letters of the alphabet, showed no early reading skills but they could scribble. The middle score group was characterized by a highly variable performance in different tasks, with better language skills in receptive and naming vocabulary, some narrative, letter knowledge, and phonological awareness (beginning sound awareness) skills. The high score group, (24.4% of the sample) had the best performance in language skills in relation to the sample data, as well as in the rest of the measured skills. Finally, scores were canonically correlated between naming, receptive vocabulary, narrative, phonological awareness, letter knowledge and initial learning of reading and writing skills for the high score group and letter knowledge, naming and receptive vocabulary for the lower score group, which is consistent with previous research in typical and ASD children. In conclusion, the obtained data is consistent with previous studies. Despite large variability, it was possible to identify performance profiles and relations based on linguistic, phonological awareness, and letter knowledge skills. These skills were predictor variables of the initial development of reading and writing. The above has implications for a future program and strategies development that may benefit the acquisition of reading and writing in ASD children.

Keywords: autism, autism spectrum disorders, early literacy, emergent literacy

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1161 CFD Study of Free Surface Flows Resulting from a Dam-Breaking

Authors: Sonia Ben Hamza, Sabra Habli, Nejla Mahjoub Saïd, Hervé Bournot, Georges Le Palec

Abstract:

Free surface flows caused by dam breaks in channels or rivers is an attention-getting subject to the engineering practice, however, the studies are few to be reported. In this paper, a numerical investigation of unsteady free surface flows resulting from a dam-breaking in a rectangular channel is studied. Numerical computations were carried out using ANSYS Fluent which is based on the finite volume approach. The air/water interface was modeled with the volume of fluid method (VOF). Verification for a typical dam-break problem is analyzed by comparing the present results with others and very good agreement is obtained. The present approach is then used to predict the characteristics of free surface flow due to the dam breaking in channel. The characteristics of complex unsteady free surface flow in these examples are clearly explained. The numerical results show that the flow became more disturbed after impacting the vertical wall, then a recirculation zone, as well as turbulence phenomena, were created. At this instant, a cavity of air was included on the flow. The results agree well with the experimental data found in the literature.

Keywords: CFD, dam-break, free surface, turbulent flows, VOF

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1160 Entrepreneurial Education in the European Union

Authors: Marko Kolaković, Mladen Turuk

Abstract:

Entrepreneurship is a valuable discipline important for the competitiveness of the European economy. The European Union's economy is constantly changing, and there is an increased demand for special knowledge and skills to help actors cope in a turbulent business environment. By promoting entrepreneurship in education, the citizens of the European Union are encouraged to be enterprising, innovative, and creative in designing solutions to perceived commercial and social problems in the form of offered products and services created as a result of the entrepreneurial process. The European Union has developed a series of guidelines to encourage entrepreneurship in education and training, and it supports entrepreneurship itself through various activities such as Erasmus + and other programs. A number of tools have been developed to support the development of entrepreneurial spirit among the citizens of the European Union. Special emphasis is placed on the methods of developing creativity, critical thinking, and the development of digital competencies. The aim of this paper is to investigate the initiatives of the European Union in the field of entrepreneurship education and to analyze the concept of entrepreneurship education in selected EU member states. Also, an overview of the desired learning outcomes acquired as a result of the successfully completed entrepreneurship education process will be provided.

Keywords: entrepreneurship, entrepreneurial education, EU, croatia

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1159 Cicadas: A Clinician-assisted, Closed-loop Technology, Mobile App for Adolescents with Autism Spectrum Disorders

Authors: Bruno Biagianti, Angela Tseng, Kathy Wannaviroj, Allison Corlett, Megan DuBois, Kyu Lee, Suma Jacob

Abstract:

Background: ASD is characterized by pervasive Sensory Processing Abnormalities (SPA) and social cognitive deficits that persist throughout the course of the illness and have been linked to functional abnormalities in specific neural systems that underlie the perception, processing, and representation of sensory information. SPA and social cognitive deficits are associated with difficulties in interpersonal relationships, poor development of social skills, reduced social interactions and lower academic performance. Importantly, they can hamper the effects of established evidence-based psychological treatments—including PEERS (Program for the Education and Enrichment of Relationship Skills), a parent/caregiver-assisted, 16-weeks social skills intervention—which nonetheless requires a functional brain capable of assimilating and retaining information and skills. As a matter of fact, some adolescents benefit from PEERS more than others, calling for strategies to increase treatment response rates. Objective: We will present interim data on CICADAS (Care Improving Cognition for ADolescents on the Autism Spectrum)—a clinician-assisted, closed-loop technology mobile application for adolescents with ASD. Via ten mobile assessments, CICADAS captures data on sensory processing abnormalities and associated cognitive deficits. These data populate a machine learning algorithm that tailors the delivery of ten neuroplasticity-based social cognitive training (NB-SCT) exercises targeting sensory processing abnormalities. Methods: In collaboration with the Autism Spectrum and Neurodevelopmental Disorders Clinic at the University of Minnesota, we conducted a fully remote, three-arm, randomized crossover trial with adolescents with ASD to document the acceptability of CICADAS and evaluate its potential as a stand-alone treatment or as a treatment enhancer of PEERS. Twenty-four adolescents with ASD (ages 11-18) have been initially randomized to 16 weeks of PEERS + CICADAS (Arm A) vs. 16 weeks of PEERS + computer games vs. 16 weeks of CICADAS alone (Arm C). After 16 weeks, the full battery of assessments has been remotely administered. Results: We have evaluated the acceptability of CICADAS by examining adherence rates, engagement patterns, and exit survey data. We found that: 1) CICADAS is able to serve as a treatment enhancer for PEERS, inducing greater improvements in sensory processing, cognition, symptom reduction, social skills and behaviors, as well as the quality of life compared to computer games; 2) the concurrent delivery of PEERS and CICADAS induces greater improvements in study outcomes compared to CICADAS only. Conclusion: While preliminary, our results indicate that the individualized assessment and treatment approach designed in CICADAS seems effective in inducing adaptive long-term learning about social-emotional events. CICADAS-induced enhancement of processing and cognition facilitates the application of PEERS skills in the environment of adolescents with ASD, thus improving their real-world functioning.

Keywords: ASD, social skills, cognitive training, mobile app

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1158 Despiking of Turbulent Flow Data in Gravel Bed Stream

Authors: Ratul Das

Abstract:

The present experimental study insights the decontamination of instantaneous velocity fluctuations captured by Acoustic Doppler Velocimeter (ADV) in gravel-bed streams to ascertain near-bed turbulence for low Reynolds number. The interference between incidental and reflected pulses produce spikes in the ADV data especially in the near-bed flow zone and therefore filtering the data are very essential. Nortek’s Vectrino four-receiver ADV probe was used to capture the instantaneous three-dimensional velocity fluctuations over a non-cohesive bed. A spike removal algorithm based on the acceleration threshold method was applied to note the bed roughness and its influence on velocity fluctuations and velocity power spectra in the carrier fluid. The velocity power spectra of despiked signals with a best combination of velocity threshold (VT) and acceleration threshold (AT) are proposed which ascertained velocity power spectra a satisfactory fit with the Kolmogorov “–5/3 scaling-law” in the inertial sub-range. Also, velocity distributions below the roughness crest level fairly follows a third-degree polynomial series.

Keywords: acoustic doppler velocimeter, gravel-bed, spike removal, reynolds shear stress, near-bed turbulence, velocity power spectra

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1157 Pathology of Explanted Transvaginal Meshes

Authors: Vladimir V. Iakovlev, Erin T. Carey, John Steege

Abstract:

The use of polypropylene mesh devices for Pelvic Organ Prolapse (POP) spread rapidly during the last decade, yet our knowledge of the mesh-tissue interaction is far from complete. We aimed to perform a thorough pathological examination of explanted POP meshes and describe findings that may explain mechanisms of complications resulting in product excision. We report a spectrum of important findings, including nerve ingrowth, mesh deformation, involvement of detrusor muscle with neural ganglia, and polypropylene degradation. Analysis of these findings may improve and guide future treatment strategies.

Keywords: transvaginal, mesh, nerves, polypropylene degradation

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