bluuebunny/crossref_metadata_2025 huggingface dataset:
Trachyspermum ammi (L.) Sprague
Authors: Moein Mahmoodreza R. , Zomorodian Kamiar , Pakshir Keyvan , Yavari Farnoosh , Motamedi Marjan , Zarshenas Mohammad M.
Published: October 2014

Resistance to antibacterial agents has become a serious problem for global health. The current study evaluated the antimicrobial activities of essential oil and respective fractions of Trachyspermum ammi (L.) Sprague. Seeds of the essential oil were extracted and fractionated using column chromatography. All fractions were then analyzed by gas chromatography/mass spectrometry. Antifungal and antibacterial activities of the oil and its fractions were assessed using microdilution method. Compounds γ-terpinene (48.07%), ρ-cymene (33.73%), and thymol (17.41%) were determined as major constituents. The effect of fraction II was better than total essential oil, fraction I, and standard thymol. The greater effect of fraction II compared to standard thymol showed the synergistic effects of the ingredients in this fraction. As this fraction and also total oil were effective on the studied microorganism, the combination of these products with current antimicrobial agents could be considered as new antimicrobial compounds in further investigations.
Online Education About Herbs and Dietary Supplements
Authors: Kemper Kathi J. , Patel Sejal
Published: October 2014

Background:

Online education is increasingly used to train health professionals, but little is known about how variations in cost affect use of elective training. We assessed whether offering registration for free increased the number of modules consumed in both absolute terms (# modules consumed per person, pp) and relative terms (# modules consumed per # modules registered).

Methods:

We analyzed results of the ‘natural experiment’ on learner's use of the OSU Center for Integrative Health and Wellness online elective curriculum, Introduction Herbs and Dietary Supplements Across the Lifespan, in which costs varied based on monthly discounts for students, faculty, staff, alumni, and members of selected professional associations.

Results:

Over 7 months there were a total of 905 registrants for 8553 modules. Most (847/905, 94%) registered for free; they completed 1505 (18%) of 8344 modules for which they registered. Fewer (58/905, 6%) people paid for registration; they completed a significantly higher percentage 90/209 (43%, P < 0.001) of modules for which they registered; those who paid full, non-discount rates had the highest completion rates (62%, P < 0.001). Free and paid registrants completed about the same average number of modules per person, pp, (1.8 pp free vs.1.6 pp paid).

Conclusion:

Although it may not contribute to financial margins, offering free online elective training addresses the institutional mission of increasing the number health professionals trained and the number of modules consumed compared with charging for training. Additional research is needed to determine the impact of pricing on educational outcomes and ultimately on patient care.
Group Online Mindfulness Training
Authors: Kemper Kathi J. , Yun Jonathan
Published: October 2014

Mindfulness-based stress reduction training is attractive, but training with an expert teacher is often inconvenient and costly. This proof-of-concept project assessed the feasibility of providing a hybrid of free online mindfulness-based stress reduction training with small group peer facilitation. Six medical students asked a family medicine resident with 5 years of meditation experience but no formal training as a teacher to facilitate 8 weekly group sessions using a free online mindfulness-based stress reduction course. They completed pre- and posttraining questionnaires online. Six of the 7 trainees completed at least half the sessions. Completers and noncompleters had similar age (29 years), gender (about half male), and health status. Changes in the expected direction were observed for perceived stress, mindfulness, resilience, and confidence in providing calm, compassionate care. The hybrid of online mindfulness-based stress reduction training with peer support is feasible. Additional research is warranted to formally evaluate the impact of this approach.
A Comparison of Traditional and Alternative Certification Routes on Classroom Management
Authors: Uriegas Brian , Kupczynski Lori , Mundy Marie-Anne
Published: October 2014

In Texas, there are different ways teachers can attain certification. Thus, teachers are entering the classroom through various certification routes with varying levels of training as the traditional and alternative programs differ in their requirements. Classroom management can determine the success or failure of teachers and students. The research involved in this study attempted to determine whether university-certified teachers differ from alternatively certified teachers in the area of classroom management as determined by referrals, while controlling for level of education, years of teaching experience, age, race, and gender at both middle and high school levels. The population for this study was the middle and high school teachers in one rural south central Texas school district. Data were collected from the school district’s personnel database as well as from the campus-level administrators. Hierarchical regressions were used to test null hypotheses and recommendations were suggested.
Anesthetic Considerations for a Patient With Hereditary Hemorrhagic Telangiectasia (Osler–Weber–Rendu Syndrome) Undergoing a Five-Box Thoracoscopic Maze Procedure for Atrial Fibrillation
Authors: Robinson Dominic , Rogers Barbara , Kapoor Ritu , Swan Joseph , Speas Gaylynn , Gutmann Rebecca
Published: October 2014

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder involving the abnormal communication of vascular structures. HHT typically presents with recurrent epistaxis and telangiectasis of the nasal and buccal mucosa, tongue, and lips. More serious manifestations of this disease include cerebral, pulmonary, gastrointestinal, and hepatic arteriovenous malformations. This case report details a 55-year-old male with HHT undergoing a five-box maze procedure for curative treatment of atrial fibrillation. Particular anesthetic considerations are described to reduce morbidity and mortality in this patient population.
Improving the Rate of Sufficient Sweat Collected in Infants Referred for Sweat Testing in Michigan
Authors: Abdulhamid Ibrahim , Kleyn Mary , Langbo Carrie , Gregoire-Bottex Myrtha , Schuen John , Shanmugasundaram Krithika , Nasr Samya Z
Published: October 2014

Objective. Sweat collected for testing should have quantity not sufficient (QNS) rate of ≤10% in babies ≤3 months of age. Michigan (MI) cystic fibrosis (CF) centers’ QNS rates were 12% to 25% in 2009. This project was initiated to reduce sweat QNS rates in MI. Methods/Steps. ( a) Each center’s sweat testing procedures were reviewed by a consultant. ( b) Each center received a report with recommendations to improve QNS rates. ( c) Technicians visited other participating centers to observe their procedures. Results. A total of 778 infants were identified as positive via CF newborn screening over a 2-year period. The mean age at time of sweat test was 23.2 days (SD ± 13.0 days). The overall QNS percent decreased from 14.4% to 9.5% ( P = .04) during the study. Conclusion. This project and teamwork approach led to a decrease of sweat test QNS rates, opportunities to solve a common problem, and improved quality of care.
The same site on the integrase-binding domain of lens epithelium–derived growth factor is a therapeutic target for MLL leukemia and HIV
Authors: Murai Marcelo J. , Pollock Jonathan , He Shihan , Miao Hongzhi , Purohit Trupta , Yokom Adam , Hess Jay L. , Muntean Andrew G. , Grembecka Jolanta , Cierpicki Tomasz
Published: October 2014

Key Points

Inhibiting LEDGF interaction with a novel fragment of MLL represents an attractive approach to develop new drugs for MLL leukemias. Structural studies reveal a new pocket on the LEDGF IBD suitable for targeting by small-molecule inhibitors.
Ibrutinib treatment affects collagen and von Willebrand factor-dependent platelet functions
Authors: Levade Marie , David Elodie , Garcia Cédric , Laurent Pierre-Alexandre , Cadot Sarah , Michallet Anne-Sophie , Bordet Jean-Claude , Tam Constantine , Sié Pierre , Ysebaert Loïc , Payrastre Bernard
Published: October 2014

Key Points

Ibrutinib affects collagen and VWF-mediated platelet activation. The bleeding diathesis correlates with defects in collagen-induced platelet aggregation and firm adhesion on VWF at arterial shear rate.
Quality of diabetes care worldwide and feasibility of implementation of the Alphabet Strategy: GAIA project (Global Alphabet Strategy Implementation Audit)
Authors: Lee James D , Saravanan Ponnusamy , Varadhan Lakshminarayanan , Morrissey John R , Patel Vinod
Published: October 2014

Background

The Alphabet Strategy (AS) is a diabetes care checklist ensuring “important, simple things are done right all the time.” Current audits of diabetes care in developed countries reveal wide variations in quality with performance of care processes frequently sub-optimal. This study had three components:

• an audit to assess diabetes care quality worldwide,

• a questionnaire study seeking opinions on the merits of the AS,

• a pilot study to assess the practicality of implementation of the AS in a low socioeconomic setting.

Methods

Audit data was collected from 52 centres across 32 countries. Data from 4537 patients were converted to Quality and Outcome Framework (QOF) scores to enable inter-centre comparison. These were compared to each country’s Gross Domestic Product (GDP), and Total Health Expenditure percentage per capita (THE%). The opinions of diabetes patients and healthcare professionals from the diabetes care team at each of these centres were sought through a structured questionnaire. A retrospective audit on 100 randomly selected case notes was conducted prior to AS implementation in a diabetes outpatient clinic in India, followed by a prospective audit after four months to assess its impact on care quality.

Results

QOF scores showed wide variation across the centres (mean 49.0, range 10.2–90.1). Although there was a positive relationship between GDP and THE% to QOF scores, there were exceptions. 91% of healthcare professionals felt the AS approach was practical. Patients found the checklist to be a useful education tool. Significant improvements in several aspects of care as well as 36% improvement in QOF score were seen following implementation.

Conclusions

International centres observed large variations in care quality, with standards frequently sub-optimal. 71% of health care professionals would consider adopting the AS in their daily practice. Implementation in a low resource country resulted in significant improvements in some aspects of diabetes care. The AS checklist for diabetes care is a freely available in the public domain encompassing patient education, care plans, and educational resources for healthcare professionals including summary guidelines. The AS may provide a unique approach in delivering high quality diabetes care in countries with limited resources.
Lysozyme-coated silver nanoparticles for differentiating bacterial strains on the basis of antibacterial activity
Authors: Ashraf Sumaira , Chatha Mariyam Asghar , Ejaz Wardah , Janjua Hussnain Ahmed , Hussain Irshad
Published: October 2014

Lysozyme, an antibacterial enzyme, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles adopting various strategies. The synthesized particles were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering (DLS), and TEM to observe their morphology and surface chemistry. The silver nanoparticles were evaluated for their antimicrobial activity against several bacterial species and various bacterial strains within the same species. The cationic silver nanoparticles were found to be more effective against Pseudomonas aeruginosa 3 compared to other bacterial species/strains investigated. Some of the bacterial strains of the same species showed variable antibacterial activity. The difference in antimicrobial activity of these particles has led to the conclusion that antimicrobial products formed from silver nanoparticles may not be equally effective against all the bacteria. This difference in the antibacterial activity of silver nanoparticles for different bacterial strains from the same species may be due to the genome islands that are acquired through horizontal gene transfer (HGT). These genome islands are expected to possess some genes that may encode enzymes to resist the antimicrobial activity of silver nanoparticles. These silver nanoparticles may thus also be used to differentiate some bacterial strains within the same species due to variable silver resistance of these variants, which may not possible by simple biochemical tests.
Astrocyte-specific regulation of hMeCP2 expression in Drosophila
Authors: Hess-Homeier David L. , Fan Chia-Yu , Gupta Tarun , Chiang Ann-Shyn , Certel Sarah J.
Published: October 2014

Alterations in the expression of Methyl-CpG-binding protein 2 (MeCP2) either by mutations or gene duplication leads to a wide spectrum of neurodevelopmental disorders including Rett Syndrome and MeCP2 duplication disorder. Common features of Rett Syndrome (RTT), MeCP2 duplication disorder, and neuropsychiatric disorders indicate that even moderate changes in MeCP2 protein levels result in functional and structural cell abnormalities. In this study, we investigated two areas of MeCP2 pathophysiology using Drosophila as a model system: the effects of MeCP2 glial gain-of-function activity on circuits controlling sleep behavior, and the cell-type specific regulation of MeCP2 expression. In this study, we first examined the effects of elevated MeCP2 levels on microcircuits by expressing human MeCP2 (hMeCP2) in astrocytes and distinct subsets of amine neurons including dopamine and octopamine (OA) neurons. Depending on the cell-type, hMeCP2 expression reduced sleep levels, altered daytime/nighttime sleep patterns, and generated sleep maintenance deficits. Second, we identified a 498 base pair region of the MeCP2e2 isoform that is targeted for regulation in distinct subsets of astrocytes. Levels of the full-length hMeCP2e2 and mutant RTT R106W protein decreased in astrocytes in a temporally and spatially regulated manner. In contrast, expression of the deletion Δ166 hMeCP2 protein was not altered in the entire astrocyte population. qPCR experiments revealed a reduction in full-length hMeCP2e2 transcript levels suggesting transgenic hMeCP2 expression is regulated at the transcriptional level. Given the phenotypic complexities that are caused by alterations in MeCP2 levels, our results provide insight into distinct cellular mechanisms that control MeCP2 expression and link microcircuit abnormalities with defined behavioral deficits.
An investigation of nutrient-dependent mRNA translation in Drosophila larvae
Authors: Nagarajan Sabarish , Grewal Savraj S.
Published: October 2014

The larval period of the Drosophila life cycle is characterized by immense growth. In nutrient rich conditions, larvae increase in mass approximately two hundred-fold in five days. However, upon nutrient deprivation, growth is arrested. The prevailing view is that dietary amino acids drive this larval growth by activating the conserved insulin/PI3 kinase and Target of rapamycin (TOR) pathways and promoting anabolic metabolism. One key anabolic process is protein synthesis. However, few studies have attempted to measure mRNA translation during larval development or examine the signaling requirements for nutrient-dependent regulation. Our work addresses this issue. Using polysome analyses, we observed that starvation rapidly (within thirty minutes) decreased larval mRNA translation, with a maximal decrease at 6–18 hours. By analyzing individual genes, we observed that nutrient-deprivation led to a general reduction in mRNA translation, regardless of any starvation-mediated changes (increase or decrease) in total transcript levels. Although sugars and amino acids are key regulators of translation in animal cells and are the major macronutrients in the larval diet, we found that they alone were not sufficient to maintain mRNA translation in larvae. The insulin/PI3 kinase and TOR pathways are widely proposed as the main link between nutrients and mRNA translation in animal cells. However, we found that genetic activation of PI3K and TOR signaling, or regulation of two effectors – 4EBP and S6K – could not prevent the starvation-mediated translation inhibition. Similarly, we showed that the nutrient stress-activated eIF2α kinases, GCN2 and PERK, were not required for starvation-induced inhibition of translation in larvae. These findings indicate that nutrient control of mRNA translation in larvae is more complex than simply amino acid activation of insulin and TOR signaling.
Transgenic mouse model of cutaneous adnexal tumors
Authors: Kito Yusuke , Saigo Chiemi , Atsushi Kurabayashi , Mutsuo Furihata , Tamotsu Takeuchi
Published: October 2014

TMEM207 was first characterized as being an important molecule for the invasion activity of gastric signet-ring cell carcinoma cells. In order to unravel the pathological properties of TMEM207, we generated several transgenic mouse lines, designated C57BL/6-Tg (ITF-TMEM207), in which murine TMEM207 was ectopically expressed under a truncated (by ~200 bp) proximal promoter of the murine intestinal trefoil factor (ITF) gene (also known as Tff3). Unexpectedly, a C57BL/6-Tg (ITF-TMEM207) mouse line exhibited a high incidence of spontaneous intradermal tumors with histopathological features that resembled those of various human cutaneous adnexal tumors. These tumors were found in ~14% female and 13% of male 6- to 12-month-old mice. TMEM207 immunoreactivity was found in hair follicle bulge cells in non-tumorous skin, as well as in cutaneous adnexal tumors of the transgenic mouse. The ITF-TMEM207 construct in this line appeared to be inserted to a major satellite repeat sequence at chromosome 2, in which no definite coding molecule was found. In addition, we also observed cutaneous adnexal tumors in three other C57BL/6-Tg (ITF-TMEM207) transgenic mouse lines. We believe that the C57BL/6-Tg (ITF-TMEM207) mouse might be a useful model to understand human cutaneous adnexal tumors.
Prediction of Tower Loading of Floating Offshore Wind Turbine Systems in the Extreme Wind and Wave Conditions
Authors: Xu Nan , Ishihara Takeshi
Published: October 2014

The analytical formulae of wind-induced load, wave-induced load and their combination are proposed for the tower of floating offshore wind turbine systems by quasi-steady analysis. Sway-rocking model (SR model) is employed as the equivalent calculation model. The formulae of wind-induced load are in the same format as those of fixed-foundation wind turbine, but have different values for some critical parameters in resonant standard deviation. For wave-induced load, the standard deviations due to surge and pitch motions are proposed separately and their combination is calculated with complete quadratic combination (CQC) rule. For the total tower loading under wind and wave, the mean value depends on the wind only, and the combination without considering any correlation can predict the standard deviation accurately. The Gaussian peak factor is applicable to both wave-induced load and the total tower loading. All the proposed formulae are verified by full dynamic simulation.
Inflow Parameter Effects on Wind Turbine Tower Cyclic Loading
Authors: Smith Jamie C. , Carriveau Rupp , Ting David S-K
Published: October 2014

Wind turbine towers are fatigue-critical structures subjected to a variety of atmospheric wind regimes at onshore installations. At a commercial wind farm in Southwestern Ontario, the structural steel supporting tower of a multi-megawatt horizontal-axis turbine has been instrumented with a fiber Bragg grating strain gauge array. A nearby meteorological mast allows wind conditions to be classified on the basis of horizontal turbulence intensity and vertical wind shear. Data has been collected over a measurement campaign spanning multiple months, and a sample of the tower's cyclic loading history has been compiled. Comparisons are drawn between accumulated hourly loading cycle spectra for operation across different upwind inflow parameters.
An Iterative Method to Optimize the Twist Angle of a Wind Turbine Rotor Blade
Authors: Capellaro Mark , Cheng Po Wen
Published: October 2014

Maximizing the power output of a wind turbine is possible by ensuring the airfoils along the blade operate at an optimal angle of attack. However, blades deflect under loading but the torsional deflection of wind turbine blades is normally ignored in the blade design process. Since the power output is dependent upon the blade twist angle, an optimized blade shape must take into account the torsional deflection of the blade. The torsional deflection changes the loading of the blade. This necessitates iterative methods to determine the equilibrium loading and deflection and to optimize the blade shape. This paper explains a method to determine the equilibrium torsional deflection of the blade and a method to determine the optimal static blade twist angle to maximize power production. The results are the blade twist angle distribution that will deform to an optimal angle of attack under load, thereby changing the peak of the coefficient of power ( CP) curve to a chosen wind speed.
CFD Analysis of Oscillating Blades for Small Horizontal Axis Wind Turbines in Dynamic Stall Condition
Authors: Raeisi B. , Alighanbari H.
Published: October 2014

Unsteady aerodynamics and specifically the dynamic stall phenomenon significantly affect the aerodynamic performance of the wind turbine blades. This paper presents a 2D computational investigation on the aerodynamic characteristics of three specific airfoils for small horizontal axis wind turbines subjected to unsteady viscous flow. The unsteady incompressible Navier-Stokes equations are considered, and ANSYS-Fluent CFD code is used for the flow simulation. The simulation method is validated by calculating the aerodynamic coefficients of a pitching NACA23012 airfoil and comparing the results with the corresponding published experimental data. A complete set of dynamic simulations is then performed to find lift and drag forces acting on the airfoils in different unsteady conditions such as various Reynolds numbers and different amplitude and frequency of pitching oscillations. The results of this study emphasize that the curvature of leading edge and the thickness of the airfoil have major roles in early flow separation and dynamic stall of a pitching airfoil. The dynamic stall has wide negative effects on the performance of the blades such as lift reduction, drag increment and delay in the flow reattachment that are discussed in this paper.
A Simple Wind Model for Fast Wind Farm Simulations
Authors: Jauch Clemens
Published: October 2014

In this article a wind model is presented that allows simulation of realistic wind speeds over the area of a wind farm. The primary propose of this model is power system simulations, where fast simulation speed is crucial, and where it is undesirable to use different tools to run a simulation. The proposed wind model combines the too simple wind models commonly used in power system simulations of wind turbines and a sophisticated wind model that represents the different wind speeds that occur across a wind turbine rotor. The result is a farm wind model for simulating the power system behaviour of a wind farm.
Effects of Wake Interaction on Downstream Wind Turbines
Authors: Choudhry Amanullah , Mo Jang-Oh , Arjomandi Maziar , Kelso Richard
Published: October 2014

The present article revisits the wake studies behind the NREL (National Renewable Energy Laboratory) Phase VI wind turbine inside a virtual wind tunnel that were recently performed at the University of Adelaide using Large Eddy Simulation (LES). A notable observation has been made in the current article, through comparisons of instantaneous contours of vorticity, velocity and turbulence intensity, that the regions of velocity deficits and high turbulence intensities in the wake are restricted to the regions of high vorticity. Therefore, for a downstream wind turbine, the smaller power production, the increased unsteady loads and the noise produced can directly be associated with the turbine blades passing through the streamwise vortices generated by the upstream wind turbine. In addition, a comparative analysis has been performed between the LES and semi-empirical models, used in the industry, to better understand the development of the wake inside the wind tunnel model. Finally, in order to illustrate the effects of wake on downstream wind turbines, a dynamic stall prediction model was used to determine the regions of the turbine blade affected by dynamic stall as a function of spacing between the turbines.
Aeroelastic Control of Wind Turbine Blade Using Trailing-Edge Flap
Authors: Li Nailu , Balas Mark J.
Published: October 2014

A mathematic rotating blade model is introduced in conjunction with periodic time-varying aerodynamic load, which is described by Beddoes-Leishman dynamic stall model. The consequent aeroelastic model is utilized to analyze blade dynamics and design control strategy for blade flutter suppression application. Aeroelastic stability of rotating blade is indicated by Floquet Theory, and the stability indications show good agreement with results of open-loop simulation test for critical flutter speed study. It's shown that the Adaptive Controller is capable of restraining flutter vibration with the actuation of the trailing-edge flap. The robustness and effectiveness of the controller are shown by closed-loop tests with a wide range of aerodynamic loads. The stability analysis proves the stability of the Adaptive Controller by the Adaptive Stability Theorem.
Dynamic Voltage Restorer for Fault Ride through of Doubly Fed Induction Generator — A Solution for a Case Study at 110/11KV Substation in India
Authors: Gangatharan Sivasankar , Velu Suresh Kumar
Published: October 2014

The wind power penetration has been increasing significantly year by year. Most of the Wind Turbine Generators (WTGs) are designed with induction generators. The induction generator based wind farms have poor fault ride through capability and any system disturbance may affect the wind power generation. The disturbances are very common, if the WTGs are connected to weak grids. One such problem of frequent tripping has been encountered at Anthiyur substation in India. Subsequently, a power quality study has been undertaken in a 110/11KV substation at Anthiyur for examining the causes for tripping. From the study, it is found that frequent grid voltage disturbances have caused the tripping. Since the contribution of wind power is in predominant percentage, maintaining its stability becomes an important issue. A simulation based solution is proposed to improve the reliability of Doubly Fed Induction Generator (DFIG) based wind farms. In the proposed strategy, Dynamic Voltage Restorer (DVR) is used to compensate the grid voltage disturbances. The DVR can compensate the faulty line voltage and enhance fault ride through capability of DFIG wind farms for a stable operation as demanded in actual grid codes. Especially, vector control technique is utilizedhere to control the DVR. The proposed control scheme is very effective to protect the DFIG and DVR from disturbances and faults.
The Frequency Response of a Cavitating Hydrofoil
Authors: Jamalabadi M.Y. Abdollahzadeh
Published: October 2014

The frequency response of a hydrofoil such as the rudder and propeller is important for ship equipment design. In the present study the cavitation reaction on a hydrofoil vibrating in a viscous fluid is constructed by superposition of a potential flow solution. An analytic expression for the fluid pressure as a function of cavitation number, ship velocity, and the incidence angle is considered in solid-fluid interaction when solving the equation of motion of the hydrofoil. The first three natural frequencies of the hydrofoil are calculated as a function of the incidence angle, the aspect ratio, the cavitation index, and the free stream velocity. The results show by the increase of the incidence angle and the aspect ratio, and the decrease of the cavitation index, and the free stream velocity, the natural frequencies increased.
Wind Effects of Architectural Details on Gable-Roofed Low-Rise Buildings in Southeastern Coast of China
Authors: Huang Peng , Tao Ling , Gu Ming , Quan Yong
Published: October 2014

Gable-roofed low-rise buildings with ridges, protruding gable walls and eaves gutters are usually found on the southeastern coast of China, which are often invaded by typhoons. The wind effects due to ridges, protruding gable walls and eaves gutters on low-rise buildings as well as the wind loads on the architectural details themselves have been studied through a series of wind tunnel tests. The mean block pressure coefficient and the negative peak block pressure coefficient on different roof regions were compared, and architectural details' single tap pressure coefficients and drag coefficients were investigated. The study shows that each of the architectural details reduces roof wind load impact to various extents, and their coexistence has a most significant effect on decreasing roof wind loads, up to the reduction of 56% on the ‘Ru’ windward region for the mean block pressure coefficient, and 47% and 45% on the ‘C1’ and ‘C2’ corner regions for the worst negative peak block pressure coefficient, respectively. The worst negative peak pressure at the interior surface of the architectural details occurs when the wind blows obliquely on the exterior surface of the architectural details. This condition leads to very large peak net pressure coefficients. The worst net pressure coefficients of the protruding gable wall, ridge and eaves gutter are about 18.0, 10.5 and 6.7, respectively. Finally, the drag coefficients on the architectural details were also examined, and the results are suitable for engineering application.
Applied Element Method Simulation of Fiber Reinforced Polymer and Polypropylene Composite Retrofitted Masonry Walls
Authors: Umair Saleem M. , Numada Muneyoshi , Meguro Kimiro
Published: October 2014

In current research work, an attempt is made to simulate the behavior of a newly proposed composite material using 3-D Applied Element Method (AEM). Fiber Reinforced Polymer (FRP) being a strong material provides a significant increase in shear strength. Polypropylene band (PP-band) not only holds the masonry wall system into a single unit but also provides a fairly high deformation capacity at a very low cost of retrofitting. A composite of FRP and PP-band is proposed and applied on the surface of masonry wall. Verification of the proposed numerical model is achieved by conducting experiments on twelve masonry wallets. Out of twelve, six masonry wallets were tested in out of plane bending test and six were tested under in-plane forces in the form of diagonal compression test. Same wallet retrofitting scheme was selected for in-plane and out of plane experiments and all of them were analyzed using proposed 3-D AEM numerical simulation tool. Proposed numerical model has served satisfactory and has shown a fairly good agreement with experimental results which encourages the use of 3D-AEM to numerically simulate the behavior of non-retrofitted and retrofitted masonry wallets.
Structural Response of Timber-Concrete Composite Beams Predicted by Finite Element Models and Manual Calculations
Authors: Khorsandnia Nima , Valipour Hamid , Crews Keith
Published: October 2014

This paper presents the structural response of timber-concrete composite (TCC) beams predicted by finite element models (i.e. continuum-based and 1D frame) and manual calculations. Details of constitutive laws adopted for modelling timber and concrete are provided and application of the Hashin damage model in conjunction with continuum-based FE for capturing failure of timber under bi-axial stress state is discussed. A simplified strategy for modelling the TCC connection is proposed in which the connection is modelled by a nonlinear spring and the full load-slip behaviour of each TCC connection is expressed with a formula that can be directly implemented in the general purpose FE codes and used for nonlinear analysis of TCC beams. The developed FE models are verified by examples taken from the literature. Furthermore, the load-displacement response and ultimate loading capacity of the TCC beams are determined according to Eurocode 5 method and compared with FE model predictions.
Spectral Matching of Real Ground Motions: Applications to Horizontally Irregular Systems in Elastic Range
Authors: Roy R. , Thakur P. , Chakroborty S.
Published: October 2014

In the context of performance-based seismic design (PBSD), ground motions are often scaled to certain convenient target spectra derived from probabilistic seismic hazard analysis (PSHA). While Uniform Hazard Spectrum (UHS) is more widely used, Conditional Mean Spectrum (CMS) is recently proposed to be more desirable for scaling of real accelerograms. In this backdrop, a set of near-field and far-field ground motions are spectrally scaled, using wavelets, to both UHS and CMS. Seismic demand of horizontally irregular structures under bi-directional ground motion is assessed under both scaled and seed records in the elastic range. Spectral matching, within limits, of both the horizontal components of real records to a single hazard spectrum is observed to adequately predict the amplification in response due to asymmetry (at least for the records and target spectra relevant to soil class D). Further, such scaling effectively reduces the variability in predicted magnification from one ground motion to other. Dynamic amplification factors recommended in international codes to apply in equivalent static design of asymmetric systems are shown to be deficient.
Damage Identification in a Plate Structure Based on Strain Statistical Moment
Authors: Xiang Wei , Wang Dansheng , Zhu Hongping
Published: October 2014

The fourth strain statistical moment (FSSM) based damage detection method has been recently proposed by the authors and the results of numerical study demonstrated the proposed method is sensitive to local structural damage but insensitive to measurement noise for beam-type structure. In this paper, the method is extended to a plate structure. The method consists of two steps: damage localization and damage quantification. First, the damage is located by using the difference curved surfaces of FSSMs in one direction of a plate subjected to Gauss White Noise (GWN) excitation before and after damage. Then the model updating method based on least square algorithm is used to estimate the damage severities. Also, the numerical (finite element) simulations are carried out for a simply supported plate. The results demonstrate the proposed method can provide good prediction of both location and severity of damage at one or more sites, even under low damage severities and high measurement noise conditions.
A Genetic Algorithm Approach for 2-D Tensegrity Form Finding
Authors: Faroughi Shirko , Kamran Mehdi Abdollahi , Lee Jaehong
Published: October 2014

This paper presents a novel and versatile method for finding 2-D tensegrity structures form finding. Using this method, different possibilities for the geometry of 2-D tensegrity structures can be found with little information about the structure. As opposed to most existing procedures this method only needs the number of each member prototype, the number of tensegrity nodes and connectivity at each node to be known. The form finding is done by minimizing objective function, which considers the rank deficiencies of the geometry, the prestress coefficients and the semi-positive definite condition of the stiffness matrix. Genetic algorithm as the global search is taken into account first for generating the connectivity matrix, initial prestress coefficients and also minimizing the objective function. Several numerical examples are given to demonstrate the competence and robustness of the current study in searching new different possibility self-equilibrium configuration of tensegrity structures.
A Simple Approach for Force Finding Analysis of Suspended-Domes Based on the Superposition Principle
Authors: Guo J.M. , Yuan X.F. , Li Y.Y. , Dong S.L.
Published: October 2014

This paper proposes a simple approach for force finding analysis of suspended-domes based on the superposition principle. First, the feasibility of the superposition principle in a suspended-dome during tension is validated using an experimental model and the corresponding numerical model. Following that, a simplified computational method for force finding based on the superposition principle is presented. Taking a suspended-dome as an illustrative example, the initial strain at zero state is calculated by force finding, and the difference between the simplified computational method and the iterative method is investigated. The results show that the superposition principle is nearly feasible during tension and the proposed simple approach is accurate and can easily obtain the actual initial pre-stress of a suspended-dome.
Damage Assessment of a Building Subjected to a Terrorist Attack
Authors: Eskew E.L. , Jang S.
Published: October 2014

An increasing threat of global terrorism has led to concerns about bombings of buildings, which could cause minor to severe structural damage. After such an event, it is important to rapidly assess the damage to the building to ensure safe and efficient emergency response. Current methods of visual inspection and non-destructive testing are expensive, subjective, and time consuming for emergency responders' usage immediately after an attack. On the other hand, vibration-based damage detection methods with wireless smart sensors could provide rapid assessment of structural characteristics with low cost. For blast analysis, structural response is usually determined using a simplified SDOF version of the undamaged structure, such as used in a Pressure-Impulse (P-I) Diagram, or using more complex FEM (finite element method) models. However, the simplified models cannot take into account damage caused by blast focus at a specific location or on a specific element, which may induce local failure leading to potential progressive collapse, and the more complex FEM models take too long to derive applicable results to be effective for a rapid structural assessment. In this paper, a new method to incorporate vibration-based damage detection methods to calculate the multi degree of freedom structural stiffness for determining structural condition is provided to create a framework for the rapid structural condition assessment of buildings after a terrorist attack. The stiffness parameters are generated from the modal analysis of the measured vibration on the building, which are then used in a numerical simulation to determine its structural response from the blast. The calculated structural response is then compared to limit conditions that have been developed from ASCE blast design codes to determine the damage assessment. A laboratory-scale building frame has been employed to validate the developed use of experimentally determined stiffness by comparing the P-I diagram using the experimental stiffness with that from numerical models. The reasonable match between the P-I diagrams from the numerical models and the experiments shows the positive potential of the method. The framework and examples of how to develop a rapid condition assessment are presented.
Passive Rotation Joint Design Considerations for Lift and Thrust Generation for a Biomimetic Flapping Wing
Authors: Lindholm Garrison J. , Cobb Richard G.
Published: October 2014

Maximizing the available lift and thrust force is important for designing efficient flapping wing micro air vehicles. Research to date showed the passive rotation joint between the wing and four-bar linkage is an important design aspect. Two key hinge parameters are the angle of attack stop and passive rotation joint stiffness. In this work these design parameters were independently varied. Their impact on lift and thrust force generation, and the ratio of the first and second system resonance frequencies were measured and compared through experiments utilizing prototype hardware of varying design. The prototype hardware and flapping wing controller is based on previous work, focused on using biomimetic wings combined with a design that only requires two piezoelectric actuators, and will be briefly reviewed. The angle of attack stops tested were 30°, 40°, 45°, 50°, and 60°. Five different passive rotation joints were tested of varying stiffness. Optimal angle of attack stops and passive rotation joint designs were found from the experimental results and combined into a best design, which was tested and compared to the optimal results from the independent designs. Results show that while individual selection of angle stop and passive rotation joint stiffness can be optimized, the intersection between the two precludes simply choosing the best of both as the best combined.
Design, Performance and Testing of a Quad Rotor Biplane Micro Air Vehicle for Multi Role Missions
Authors: Hrishikeshavan Vikram , Bogdanowicz Christopher , Chopra Inderjit
Published: October 2014

It is useful to combine hover and forward flight capability of air vehicles into a hybrid design. This paper discusses the development of one such hybrid air vehicle: Quadrotor biplane. The proof-of-concept vehicle weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the propeller-wing was investigated in non-axial flow conditions through a systematic series of wind tunnel experiments. The effect of the wing on propeller slipstream and vice versa significantly changed the magnitude of vertical and horizontal forces when compared with the forces produced by an isolated propeller. Accounting for these effects, trim analysis showed that the maximum speed of 11 m/s at 0 deg shaft angle and a cruise speed of 4 m/s at 18 deg shaft angle was achievable. The cruise power was approximately one-third of that required for hover. Free flight testing of the proof-of-concept vehicle successfully showed feasibility of vehicle to achieve equilibrium transition flight. In order to improve performance, a few key design parameters such as airfoil profile, wing aspect ratio, biplane wing spacing and offset between propeller axis and wing chord were also experimentally investigated. It was found that a careful trade-off between efficiency and compactness affects the final choice of the design.
Evaluation of the Thorax of Manduca Sexta for Flapping Wing Micro Air Vehicle Applications
Authors: Cranston Brian , Palazotto Anthony
Published: October 2014

In the 1990's, DARPA awarded several contracts to companies to research, design, and construct a Flapping Wing Micro Air Vehicle (FWMAV). The tobacco hornworm hawkmoth ( Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique dynamic load device was designed and constructed to mechanically actuate the upstroke and downstroke of the M.sexta in order to achieve the full flapping motion. Additionally, the forces applied through the flight muscles were directly measured in order to attain the power requirements of the flight muscles simultaneously. The experiment yielded wing stroke values of + 60 and – 35 degrees, which is what is seen in nature during hovering. The DVM and DLM muscle groups were calculated to have a power density of 112 W/kg with the vehicle energy density being 2.5 W/kg. The power output requirement indicates the need for a lightweight and energy-dense power source/actuator combination for the development of FWMAVs.
Numerical Analysis of the Primary Breakup Applying the Embedded DNS Approach to a Generic Prefilming Airblast Atomizer
Authors: Sauer Benjamin , Sadiki Amsini , Janicka Johannes
Published: October 2014

An improved understanding of the breakup processes of two-phase flows is essential to effectively control the fuel atomization for future aircraft engines. A detailed insight into the phenomena of primary breakup is a major limitation in gaining this knowledge. Aircraft engines use airblast atomizers to provide the fuel atomization. The geometries of airblast atomizers are complex, the operating conditions are characterized by high Reynolds- and Weber numbers. Direct Numerical Simulations (DNS) of liquid breakup under realistic conditions and geometries are hardly possible. The embedded DNS (eDNS) concept aims to fill this gap. The concept consists of three steps: a geometry simplification, the generation of realistic boundary conditions for the DNS and the DNS of the breakup region. The realistic annular airblast atomizer geometry is simplified to a planar geometry. Inside this domain the eDNS is located. The eDNS domain requires the generation of boundary conditions. A zonal Large Eddy Simulation (LES) of the turbulent channel flow is performed prior to the DNS. The parameters are stored transiently on the “virtual” DNS inlet planes. These variables are then mapped to the DNS. The Volume of fluid (VOF) method is used to solve for the two-phase flow. DNS are performed for a shear-driven liquid wall film and for a generic planar prefilming airblast atomizer. As the Reynolds and Weber number for the first operating point (OP) are low (Reair = 5,333/Wefilm = 1.9), the liquid wall film as well as the liquid sheet show no surface waves. For the second case with Reair = 13,333 and We film = 11.9, the surface appears more wrinkled and streamwise waves are transported along the wall for the shear-driven wall film. Instantaneous snapshots in 2–D and 3–D illustrate the qualitative behavior of the liquid sheet in time. Leaving the prefilmer trailing edge, the liquid sheet starts to oscillate in a sinusoidal fashion. This oscillation appears crucial for the onset of primary breakup. The qualitative characterization of the breakup for OP 1 and OP 2, yield to the distinction of the stretched ligament breakup for the former, and the torn-sheet breakup for the latter O P. The breakup time for OP 1 is longer than for OP 2. This study proves the applicability of the eDNS concept for investigating breakup processes as the transient nature of the phase interface behavior can be captured. The approach offers the potential of simulating realistic annular highly-swirled airblast atomizer geometries under realistic conditions.
DNS of Dispersed Multiphase Flows with Heat Transfer and Rarefaction Effects
Authors: Ström Henrik , Sasic Srdjan
Published: October 2014

We propose a method for DNS of particle motion in non-isothermal systems. The method uses a shared set of momentum and energy balance equations for the carrier-and the dispersed phases. Measures are taken to ensure that non-deformable entities (solid particles) behave like rigid bodies. Moreover, deformable entities (e.g. bubbles) as well as rarefaction effects can be accommodated. The predictions of the method agree well with the available data for isothermal solid particles motion in the presence of walls and other particles, natural convection around a stationary particle, solid particles motion accompanied with heat transfer effects and isothermal solid particles motion under rarefied conditions. The method is used to investigate the simultaneous effects of heat transfer and rarefaction on the motion of a solid catalyst particle in an enclosure, the interaction of a solid particle and a microbubble in a flotation cell and a case with more than 1000 particles.