bluuebunny/crossref_metadata_2025 huggingface dataset:
A brachytic dwarfism trait (dw) in peach trees is caused by a nonsense mutation within the gibberellic acid receptor PpeGID1c
Authors: Hollender Courtney A. , Hadiarto Toto , Srinivasan Chinnathambi , Scorza Ralph , Dardick Chris
Published: December 2015

Little is known about the genetic factors controlling tree size and shape. Here, we studied the genetic basis for a recessive brachytic dwarfism trait (dw) in peach (Prunus persica) that has little or no effect on fruit development.

A sequencing‐based mapping strategy positioned dw on the distal end of chromosome 6. Further sequence analysis and fine mapping identified a candidate gene for dw as a non‐functional allele of the gibberellic acid receptor GID1c.

Expression of the two GID1‐like genes found in peach, PpeGID1c and PpeGID1b, was analyzed. GID1c was predominantly expressed in actively growing vegetative tissues, whereas GID1b was more highly expressed in reproductive tissues. Silencing of GID1c in plum via transgenic expression of a hairpin construct led to a dwarf phenotype similar to that of dw/dw peaches. In general, the degree of GID1c silencing corresponded to the degree of dwarfing.

The results suggest that PpeGID1c serves a primary role in vegetative growth and elongation, whereas GID1b probably functions to regulate gibberellic acid perception in reproductive organs. Modification of GID1c expression could provide a rational approach to control tree size without impairing fruit development.
Host nutritional status mediates degree of parasitoid virulence
Authors: Maure Fanny , Thomas Frédéric , Doyon Josée , Brodeur Jacques
Published: December 2015

Parasitic organisms rely on the resources of their hosts to obtain nutrients essential for growth and reproduction. Insect parasitoids constitute an extreme condition since they develop in a single host from which they typically consume all available resources. As a result, the host is killed following parasitism. However, a few intriguing cases of host survival have been reported wherein hosts resume foraging and may even reproduce following parasitoid emergence. Yet, the ultimate and proximate mechanisms responsible for host recovery remain unresolved. We tested the impact of host nutrition on host fate and parasitoid fitness, using the association between Dinocampus coccinellae and the spotted lady beetle Coleomegilla maculata. Under laboratory conditions, we fed parasitized ladybirds on different aphid diets, with or without pollen. In the field, we followed the fate of parasitized ladybirds during seasonal variations in pollen and aphid abundance. We found that ladybirds fed on aphids or a combination of aphids and pollen recovered more frequently from parasitism (from 65 to 81%) than those eating only pollen (48%). Field data suggest that the fate of parasitized ladybirds is also related to food availability. On the other hand, when hosts fed on a combination of aphids and pollen, consequences for parasitoid fitness were often ‘all‐or‐nothing’: parasitoid emergence rate was the lowest of all host nutrition regimes (∼50%), but parasitoids that did emerge were larger than individuals emerging from other host nutrition regimes. Laboratory and field results concur to show that host nutritional status during parasitoid development significantly influences both host fate and parasitoid fitness.
Religion and Comics
Authors: Brackett Jeffrey M.
Published: December 2015

Comics and graphic novels are increasingly popular today, and there are numerous ways one can incorporate them into the Religious Studies classroom. Using comics is not, however, driven solely by their popularity; rather, the ability to select wide‐ranging theoretical and methodological approaches to comics creates opportunities for instructors to meet their pedagogical goals and course outcomes in exciting new ways. This essay aims to introduce a variety of scholarly resources, as well as a sample of comics rife with religious themes, for instructors considering using comics in the classroom. One can readily adapt the secondary readings, comics, and approaches to fit one's institutional location and pedagogical preferences.
The Babylonian Theodicy: An Ancient Babylonian Discourse on Human Piety and Divine Justice
Authors: Oshima Takayoshi
Published: December 2015

The ancient Babylonian poem known by its modern title ‘Babylonian Theodicy’ is written in a dialogue form between two men. They exchange views on the meaning of worship of the gods and its benefit. Although the poem does not specify their identities, judging from the contents, it seems that the protagonists are based on ancient scribes or temple scholars. It is very likely that they were also the intended audience of this poem. The first protagonist, customarily called ‘the sufferer’, repeatedly bewails his unrewarded devotion to the gods and unmerited plight. Apparently, his worldview was moulded by the traditional Mesopotamian belief: various Sumero‐Babylonian didactic texts teach that, for demonstrating piety by means of prayers, gifts, libation and offerings, the gods will reward people with health and wealth. These ancient precepts also warn people of possible divine punishments for neglecting cultic obligations. The sufferer of the Babylonia Theodicy presents his plight and the richness of the godless as the proof of the senselessness of piety. On the other hand, the second protagonist, apparently an older and more learned man than the sufferer, advocates worship of the gods. He asserts that, unlike wild animals, humankind is capable of acknowledging the divine and, through rituals, can gain insights into the divine wisdom, no matter how incomprehensible the gods' decisions might seem. He also teaches that the true reward for one's piety is not wealth but divine grace. Judging from the fact that the sufferer eventually accepts the friend's position, it is very likely that, unlike previously suggested by various scholars, its author actually identified himself with the second protagonist, the friend.
Social Formation in the Study of Religion
Authors: Redden Jason
Published: December 2015

This article traces the development of the concept social formation in the study of religion. Beginning with the work of Burton Mack and Russell McCutcheon, two scholars who have written explicitly on the concept, the article outlines points of connection between social formation theory and other social constructivist work currently set within the discipline of religion as well as extra‐disciplinary work on ethnogenesis and the construction of ethnic identity. Lastly, with reference to the work of Tyler Roberts, the article considers some critical appraisal of the concept and speculates on how some such criticism might be addressed in an effort to enrich social formation theory.
Middle‐aged to elderly women have a higher asymptomatic infection rate with Mycobacterium avium complex, regardless of body habitus
Authors: Nishimura Tomoyasu , Fujita‐Suzuki Yukiko , Mori Masaaki , Carpenter Stephen M. , Fujiwara Hiroshi , Uwamino Yoshifumi , Tamizu Eiko , Yano Ikuya , Kawabe Hiroshi , Hasegawa Naoki
Published: December 2015

Mycobacterium avium complex (MAC) pulmonary disease is prevalent in middle‐aged to elderly women with a thin body habitus. By comparing the rate of serologically diagnosed asymptomatic MAC infection and body mass index among 1033 healthy subjects, we find that middle‐aged to elderly women became infected with MAC, regardless of their body habitus.
Study of Influence of Regional Geodynamic Background on Strata Behaviors in China's Tongxin Mine
Authors: Chen Ying , Zhang Hongwei , Yu Bin , Zhu Zhijie , Wu Wenda , Li Yunpeng
Published: December 2015

Strata behaviors are mainly affected by regional geodynamic background. The influence of rock mass stress and energy distribution on strata behaviors in the Tongxin mine is studied in terms of regional tectonic movement, seismic activity and tectonic stress field. The results show that the extrusion lifting movement of Kouquan fault adjacent to the Tongxin mine results in the stress concentration in the rock of the Carboniferous coal bed and accumulation of a large amount of elastic energy and forms structural background of Tongxin mine. Due to various seismic activities in the mine area, the strain energy is known to reach much higher levels, up to 0.5×108 J1/2. Since the stratigraphic structure is sensitive to the mining operation, the strain energy could cause strong strata behaviors. A special geological structure model of the Tongxin mine is established based on the geodynamic division method. The distribution of regional structure stress field is determined by the rock mass stress analysis system. Based on this model, Tongxin mine is divided into five areas with high stress, eight areas with low stress and eight areas with gradient stress. The strong strata behaviors mostly occur in high stress areas. These results could provide guidance to predict the strength of regional or mine pressure and control strata behavior in different areas.
Identification of a novel HLA‐A*02 allele, HLA‐A*02:432, in a Chinese individual
Authors: Jin S.‐Z. , Li Z. , Zou H.‐Y.
Published: December 2015

A*02:432 differs from A*02:07:01 by one nucleotide change at nucleotide 572 in exon 3 from G to C.
Development and application of multiple immunofluorescence staining for diagnostic cytology of canine and feline lymphoma
Authors: Sawa Mariko , Yabuki Akira , Setoguchi Asuka , Yamato Osamu
Published: December 2015

Background

Immunophenotyping of canine and feline lymphoma to determine B‐cell or T‐cell origin is important for predicting prognosis and for development of treatment protocols. For advanced diagnostic cytology tests that can be performed on smears are required to predict the immunophenotype of lymphomas.

Objectives

The aim of this study was to develop a multiple immunofluorescence (MIF) staining method for the determination of lymphocyte immunophenotype in cytologic specimens, and to evaluate its clinical utility.

Methods

B cells and T cells were detected using anti‐CD79α and anti‐CD3 antibodies, respectively, followed by specific fluorescence‐labeled secondary antibodies. The MIF staining method was first developed using fresh‐frozen sections of normal canine lymph nodes. The optimal fixative, the necessity of antigen retrieval (AR), and the optimal concentration of the antibodies were determined. The MIF method was then applied to smears of normal lymph nodes, and to clinical samples from dogs and cats with lymphoma. The MIF results were compared to genetic clonality results.

Results

B and T cells were detected based on specific fluorescence in frozen sections, using formalin fixation without AR. Specific fluorescence was also detected in smears from normal lymph nodes and lymphomas, and the immunophenotypes predicted from this MIF staining method completely corresponded to those from genetic clonality analysis.

Conclusions

The MIF staining method that we developed in this study effectively distinguished lymphocyte immunophenotypes with high specificity and sensitivity using a single smear sample, and was useful as a diagnostic tool for canine and feline lymphoma.
Traumatic tracheal diverticulum corrected with resection and anastomosis during one‐lung ventilation and total intravenous anesthesia in a cat
Authors: Sayre Rebecca S. , Lepiz Mauricio , Wall Corey , Thieman‐Mankin Kelley , Dobbin Jennifer
Published: December 2015

Objective

This report describes the clinical findings and diagnostic images of a traumatic intrathoracic tracheal avulsion with a tracheal diverticulum in a cat. Furthermore, a complete description of the tracheal resection and anastomosis using one‐lung ventilation (OLV) with total and partial intravenous anesthesia is made.

Case Summary

A 3‐year‐old neutered male domestic shorthair cat weighing 6.8 kg was presented to the University Teaching Hospital for evaluation of increased respiratory noise 3 months following unknown trauma. Approximately 12 weeks prior to presentation, the cat had been seen by the primary care veterinarian for respiratory distress. At that time, the cat had undergone a tracheal ballooning procedure for a distal tracheal stricture diagnosed by tracheoscopy. The tracheal ballooning had provided only temporary relief. At presentation to our institution, the cat had increased respiratory effort with harsh upper airway noise auscultated during thoracic examination. The remainder of the physical examination was normal. Diagnostics included a tracheoscopy and a thoracic computed tomographic examination. The cat was diagnosed with tracheal avulsion, pseudotrachea with a tracheal diverticulum, and stenosis of the avulsed tracheal ends. Surgical correction of the tracheal stricture via a thoracotomy was performed using OLV with total and partial intravenous anesthesia. The cat recovered uneventfully and at last follow‐up was active and doing well.

Unique Information Provided

This case report describes OLV using standard anesthesia equipment that is available at most private practices. Furthermore, this case describes the computed tomographic images of the intrathoracic tracheal avulsion and offers a positive outcome for tracheal resection and anastomosis.
Imaginarios urbanos y segregación socioespacial. Un estudio de caso sobre Quito
Authors: Santillán Cornejo Alfredo
Published: December 2015

El artículo expone los resultados de la aplicación del marco conceptual y metodológico de imaginarios urbanos de un estudio de caso sobre la ciudad de Quito como herramienta útil, con el fin de comprender la forma como se representa la segregación socioespacial que ha caracterizado históricamente a la capital ecuatoriana. Los hallazgos obtenidos apuntan a que la adscripción espacial constituye un elemento determinante de los imaginarios que dan sentido a las fronteras intraurbanas y, de esta manera, las producciones imaginarias permiten reconstruir, en el plano simbólico, las tensiones que conllevan las desigualdades sociales y espaciales.
Planeación en sistemas complejos: el enfoque comunicativo en la formulación de planes de desarrollo urbano
Authors: Gutiérrez Chaparro Juan José
Published: December 2015

La complejidad que caracteriza a los sistemas territoriales en la actualidad exige un cambio en la concepción de los instrumentos de conducción de su desarrollo. La experiencia demuestra que las tradicionales formas de planeación han sido superadas, entre otras razones, porque el conocimiento disponible en este campo es insuficiente para explicar la compleja problemática que caracteriza los ámbitos territoriales. Las actuaciones públicas han logrado resolver parcialmente la complejidad presente y, desde el campo de de la teoría de planeación, el análisis se dirige a explorar las contribuciones del enfoque comunicativo como paradigma emergente de nuestro campo de conocimiento y destacan sus aportaciones en materia de renovación de los actuales esquemas de intervención territorial que favorecen la participación y el consenso social.
La calidez en enfermería: formulación de constructo y variables relacionadas
Authors: Lagos Sánchez Zita Elena , De Mattos-Pimenta Cibele Andrucioli , Urrutia María Teresa
Published: December 2015

La calidez es un fenómeno subjetivo fundamental en las relaciones personales. La calidez se contagia y, así, puede ser un factor favorecedor en el cuidado, mas no existe consenso en su definición ni dominios. Medir la calidez es significativo, pues es un predictor de satisfacción usuaria; sin embargo, no se encontraron modos de medirla, lo que motivó esta revisión. Objetivos: Identificar en la revisión teórica comportamientos
que representen la calidez del enfermero y operar el constructo calidez en enfermería y variables relacionadas. Método: Revisión integrativa que abarcó la exploración y análisis de la evidencia sobre calidez, la cual corresponde a la primera etapa del proyecto de investigación titulado: Construcción y validación de una escala de medición de la calidez presente en los enfermeros, donde se pretende construir y validar una
escala que permita medir este fenómeno. Se revisaron definiciones de calidez en diccionarios, textos y artículos de diversas bases de datos. Los descriptores utilizados fueron: calidez, calidez y enfermería, en español e inglés. Para definir el constructo y sus variables se complementó el modelo de tres fases de Luiz Pasquali con los procedimientos
de Ethel Bauzer y Floyd Fowler. Resultados: Se formuló el constructo calidez en enfermería, se identificaron 2 dominios, 28 variables verbales, 9 no verbales y 93 comportamientos. Conclusiones: Los resultados de la fase teórica del modelo aplicado permitieron formular constructo, dominios y variables de calidez en enfermería. Estos aportes son de interés para la gestión del cuidado enfermero y enseñanza, pues
se relacionan directamente con la satisfacción usuaria.
Significado que construye el personal de enfermería sobre los cuidadores familiares de personas hospitalizadas
Authors: Escobar Ciro Carmen Liliana , Cardozo Garcia Yadira , Mejia Arango Olga Liliana , Muñoz Cardona Monica Johana , Cuartas Velasquez Paula Andrea
Published: December 2015

Objetivo: Conocer el significado que construye el personal de enfermería sobre los cuidadores familiares de personas hospitalizadas. Método: Cualitativa con enfoque etnográfico. Se realizaron 13 entrevistas y 50 horas de observación participante. Los participantes fueron el personal de enfermería que labora en salas de medicina interna en dos instituciones de la ciudad de Medellín, Colombia. El análisis se hizo a
partir de la lectura de relatos, observaciones y notas de campo; se extractaron códigos que se agruparon en categorías y se procedió a la interpretación de los hallazgos. Resultados: Para el personal de enfermería el cuidador es importante en el ámbito hospitalario en la medida que está pendiente, colabora, facilita el cuidado y se interesa
en aprender. En contraposición, es un obstáculo, porque no participa en las actividades de cuidado al paciente en el hospital, ya sea por miedo o falta de conocimientos. El contexto hospitalario no condiciona el significado que construye el personal de enfermería acerca del cuidador familiar, pues si bien el modelo de cuidado en ambas instituciones está centrado en el paciente y la familia, el cuidador familiar se utiliza
como recurso alternativo de cuidado, sin considerar sus necesidades y vulnerabilidad en el ambiente hospitalario. Conclusiones: El personal de enfermería construye el significado acerca del cuidador familiar en el hospital de acuerdo con su utilidad o no en el apoyo que este realiza para las actividades de cuidado.

 
Oxidation Performance Coating for Future Supercritical Power Plants
Authors: Oksa Maria , Tuurna Satu , Metsäjoki Jarkko , Penttilä Sami
Published: December 2015

For improved efficiency and reduced emissions, the future power plants need to operate at high temperatures and pressures, which however are limited by the durability of conventional materials such as ferritic steels. Steam oxidation of a number of coatings (Al slurries, thermal spraying, chemical vapor deposition siliconizing, and nickel plating) has demonstrated the feasibility of coatings to improve oxidation resistance. Al slurry coatings combine good high-temperature oxidation resistance through the growth of an Al2O3 layer and the possibility to apply the coating on an industrial scale at moderate cost. This work aimed to test the oxidation performance of coatings and reference alloys in ultra-supercritical (USC) water. The tested materials included Al slurry coating on ferritic 9%Cr steel and nickel-based A263 substrates, and bulk P92, MARBN, and A263 alloys as reference specimens. Oxidation resistance was tested by exposure to flowing supercritical water (SCW) with 125 ppb dissolved oxygen at 650°C (1202°F)/25  MPa (3625 psi) up to 1000 hr.
A Simple Constitutive Model for Prediction of Single-Peak Flow Curves Under Hot Working Conditions
Authors: Baktash Roxana , Mirzadeh Hamed
Published: December 2015

The hot flow stress of a typical stainless steel was modeled by the Hollomon equation, a modified form of the Hollomon equation, and another modified form based on the Fields–Backofen equation. The coupled effect of the deformation temperature and strain rate was also taken into account in the proposed formulae by consideration of the Zener–Hollomon parameter or dependency of the constants on temperature. The modified Fields–Backofen equation was found to be appropriate for prediction of flow stress, in which the incorporation of peak strain and consideration of temperature dependencies of the strain rate sensitivity and the stress coefficient were found to be beneficial. Moreover, the simplicity of the proposed model justifies its applicability for expressing hot flow stress characterizing dynamic recrystallization (DRX).
Experimental Investigation of the Effect of Cyclic Loading on Spudcan Extraction
Authors: Kohan Omid , Cassidy Mark J. , Gaudin Christophe , Bienen Britta
Published: December 2015

Self-elevating mobile jack-up units have been employed in offshore exploration and development in shallow waters at depths of up to approximately 150 m. Jack-ups are designed to move to a new site after operations are completed. The spudcan footings, which can be embedded up to three diameters deep in soft soil, must therefore be extracted by jacking down the hull into the water and then floating it beyond the neutral draft. This provides the maximum pull-out force to overcome the soil resistance to the jack-ups, but this force may not be sufficient. Problematic cases of this offshore are reported to take up to 10 weeks to extract, a costly exercise for the industry. A method sometimes used offshore is to cycle the spudcans vertically in an attempt to free them. This can be achieved by pushing and pulling the leg by leaving the hull afloat in the water and allowing the impact of small amplitude waves on the hull to generate cyclic loads on the spudcan. This paper reports a series of centrifuge tests investigating the ability to extract a spudcan under regular and irregular cyclic loading. Spudcan extraction tests were performed from a depth of three spudcan diameters in normally consolidated clay in a geotechnical beam centrifuge. The results demonstrate that successful extraction is dependent on the combination of mean pull-out load and the amplitude of the cycling. It is also shown that insufficient tensile static loads and prolonged small cyclic loads result in the dissipation of the negative excess pore pressure at the spudcan invert caused by the buoyancy of the hull in excess of neutral draft. It results in consolidation of soil and changes in the shear strength of the soil and consequently either extraction of the spudcan after a long period of time or unsuccessful leg extraction.
Fatigue Strength Assessment on a Multiplanar Tubular KK-Joints by Scaled Model Test
Authors: Jingxia Yue , Yuliang Liu , Chi Zhang , Qi Zeng , Zhifan Dang
Published: December 2015

Multiplanar tubular KK-joints are one of the most popular joint types in offshore structures, which are exposed to cyclic loads and fatigue damages. In this paper, a fatigue prediction method based on scaled model test is proposed. First, a scaled KK-joint, including deviations for model simplification, was designed based on sensitive analysis and similarity analysis. Then, static and fatigue tests on the scaled model under axial loading were performed, by which hot spot stress (HSS) distributions and the maximum HSS were recorded. From the test, the fatigue crack initiates from the location of the maximum HSS and propagates along the weld toe. Finally, the maximum HSS of original KK-joint was deduced by finite element analysis (FEA), and then, the fatigue life was predicted accordingly and compared with the rule-based result.
Characterization of Flow Within a Fuel Cell Manifold Subject to Asymmetric Inlet Conditions
Authors: Grega Lisa , Kothari Manthan , Specian Andrew , Voinier Steven
Published: December 2015

Achievement of flow uniformity among cells of a fuel cell stack continues to be an issue in fuel cell design and can affect performance and longevity. While many studies have sought to examine the effects of manifold and cell geometries on stack pressure drops and current density, few have provided detailed mapping of the manifold flowfield or examined the effect of reactant supply pipe bends on this flow, as these bends can introduce flow asymmetries within the pipe downstream of the bend. A simplified scaled up model of a proton exchange membrane (PEM) fuel cell was fitted with different inlet flow configurations, including straight piping and piping containing a 90 deg bend and 180 deg bend prior to entering the manifold. Particle image velocimetry (PIV) was used to obtain mean and fluctuating velocity statistics within the manifold and in individual cells. These distributions were compared with previous results using a partially developed square inlet profile, as well as available experimental and computational data in the literature. The presence of pipe bends resulted in highly skewed flow within the manifold, which also affected the flow distribution among individual cells.
A Simplified Model Predicting the Kelvin–Helmholtz Instability Frequency for Laminar Separated Flows
Authors: Simoni Daniele , Ubaldi Marina , Zunino Pietro
Published: December 2015

A semi-empirical model for the estimation of the Kelvin–Helmholtz (KH) instability frequency, in the case of short laminar separation bubbles over airfoils, has been developed. To this end, the Thwaites's pressure gradient parameter has been adopted to account for the effects induced by the aerodynamic loading distribution as well as by the Reynolds number on the separated shear layer thickness at separation. The most amplified frequency predicted by linear stability theory (LST) for a piecewise linear profile, which can be considered as the KH instability frequency, has been related to the shear layer thickness at separation, hence to the Reynolds number and the aerodynamic loading distribution through the Thwaites's pressure gradient parameter. This procedure allows the formulation of a functional dependency between the Strouhal number of the shedding frequency based on exit conditions and the dimensionless parameters. Experimental results obtained in different test cases, characterized by different Reynolds numbers and aerodynamic loading distributions, have been used to validate the model, as well as to identify the regression curve best fitting the data. The semi-empirical correlation here derived can be useful to set the activation frequency of active flow control devices for the optimization of boundary layer separation control strategies.
Self-Excited Blade Vibration Experimentally Investigated in Transonic Compressors: Rotating Instabilities and Flutter
Authors: Holzinger F. , Wartzek F. , Jüngst M. , Schiffer H.-P. , Leichtfuss S.
Published: December 2015

This paper investigates the vibrations that occurred on the blisk rotor of a 1.5-stage transonic research compressor designed for aerodynamic performance validation and tested in various configurations at Technische Universität Darmstadt. During the experimental test campaign, self-excited blade vibrations were found near the aerodynamic stability limit of the compressor. The vibration was identified as flutter of the first torsion mode and occurred at design speed as well as in the part-speed region. Numerical investigations of the flutter event at design speed confirmed negative aerodynamic damping for the first torsion mode, but showed a strong dependency of aerodynamic damping on blade tip clearance (BTC). In order to experimentally validate the relation between BTC and aerodynamic damping, the compressor tests were repeated with enlarged BTC for which stability of the torsion mode was predicted. During this second experimental campaign, strong vibrations of a different mode limited compressor operation. An investigation of this second type of vibration found rotating instabilities to be the source of the vibration. The rotating instabilities first occur as an aerodynamic phenomenon and then develop into self-excited vibration of critical amplitude. In a third experimental campaign, the same compressor was tested with reference BTC and a nonaxisymmetric casing treatment (NASCT). Performance evaluation of this configuration repeatedly showed a significant gain in operating range and pressure ratio. The gain in operating range means that the casing treatment successfully suppresses the previously encountered flutter onset. The aeroelastic potential of the NASCT is validated by means of the unsteady compressor data. By giving a description of all of the above configurations and the corresponding vibratory behavior, this paper contains a comprehensive summary of the different types of blade vibration encountered with a single transonic compressor rotor. By investigating the mechanisms behind the vibrations, this paper contributes to the understanding of flow-induced blade vibration. It also gives evidence to the dominant role of the tip clearance vortex in the fluid–structure-interaction of tip critical transonic compressors. The aeroelastic evaluation of the NASCT is beneficial for the design of next generation casing treatments for vibration control.
Full-Scale Turbine Vane Endwall Film-Cooling Effectiveness Distribution Using Pressure-Sensitive Paint Technique
Authors: Shiau Chao-Cheng , Chen Andrew F , Han Je-Chin , Azad Salam , Lee Ching-Pang
Published: December 2015

Researchers in gas turbine field take great interest in the cooling performance on the first-stage vane because of the complex flow characteristics and intensive heat load that comes from the exit of the combustion chamber. A better understanding is needed on how the coolant flow interacts with the mainstream and the resulting cooling effect in the real engine especially for the first-stage vane. An authentic flow channel and condition should be achieved. In this study, three full-scale turbine vanes are used to construct an annular-sector cascade. The film-cooling design is attained through numerous layback fan-shaped and cylindrical holes dispersed on the vane and both endwalls. With the three-dimensional vane geometry and corresponding wind tunnel design, the true flow field can thus be simulated as in the engine. This study targets the film-cooling effectiveness on the inner endwall (hub) of turbine vane. Tests are performed under the mainstream Reynolds number 350,000; the related inlet Mach number is 0.09; and the freestream turbulence intensity is 8%. Two variables, coolant-to-mainstream mass flow ratios (MFR = 2%, 3%, and 4%) and density ratios (DR = 1.0 and 1.5), are examined. Pressure-sensitive paint (PSP) technique is utilized to capture the detail contour of film-cooling effectiveness on the inner endwall and demonstrate the coolant trace. The presented results serve as a comparison basis for other sets of vanes with different cooling designs. The results are expected to strengthen the promise of PSP technique on evaluating the film-cooling performance of the engine geometries.
Modeling of Thermal Cracking Furnaces Via Exergy Analysis Using Hybrid Artificial Neural Network–Genetic Algorithm
Authors: Alizadeh M. , Sadrameli S. M.
Published: December 2015

In this study, we try to make an exergy analysis of an olefin cracking furnace more understandable by coupling it with the use of an artificial neural network–generic algorithm (ANN–GA) modeling. The presented method permits to provide an energy diagnosis of the process under a wide range of operating conditions. As a case study, one of the petrochemical complexes in Iran has been considered. The Petrosim process simulator software was used to obtain thermodynamic properties of the process streams and to perform exergy balances. The results are validated with industrial data obtained from the plant. The exergy destruction and exergetic efficiency for the main system components and the entire system were calculated. The simulation results reveal that the exergetic loss of the process increases with increasing steam ratio (SR) and decreases with coil outlet temperature (COT) and residence time (RT). The results show that the overall exergetic efficiency of the system is about 65%. The recorded and calculated data have been used as inputs for the neural network. The results show that ANN–GA is a highly effective method to optimize the performance of the neural networks, predicting the overall exergy efficiency. Comparing to phenomenological modeling based on the detailed knowledge of the furnace condition, the use of the introduced ANN–GA model saves significant amount of the time needed for the performance prediction of cracking furnaces.
A New Thermophysical Property Estimation Approach Based on Calibration Equations and Rescaling Principle
Authors: Chen Y. Y. , Keyhani M. , Frankel J. I.
Published: December 2015

A novel thermophysical property estimation method is proposed, which incorporates both calibration and rescaling principles for estimating both unknown thermal diffusivity and thermal conductivity of materials. In this process, temperature and heat flux calibration equations are developed, which account for temperature-dependent thermophysical property combinations. This approach utilizes a single in-depth temperature measurement and a known set of boundary conditions. To acquire both thermal diffusivity and thermal conductivity, two distinct stages are proposed for extracting these properties. The first stage uses a temperature calibration equation for estimating the unknown thermal diffusivity. This process determines the thermal diffusivity by minimizing the residual of the temperature calibration equation with respect to the thermal diffusivity. The second stage uses the estimated thermal diffusivity and a heat flux calibration equation for estimating the unknown thermal conductivity. This stage produces the desired thermal conductivity by minimizing the residual of the heat flux calibration equation with respect to the thermal conductivity. Results verify that the proposed estimation process works well even in the presence of significant measurement noise for the chosen two representative materials. The relative error between the exact properties and the estimated values is shown to be small. For both test materials (stainless steel 304 and a representative carbon composite), the maximum relative prediction error is approximately 2–3%. Finally, as an added benefit, this method does not require explicit knowledge of the slab thickness or sensor position which further reduces systematic errors.
Investigation of Flutter Mechanisms of a Contra-Rotating Open Rotor
Authors: Stapelfeldt Sina C. , Parry Anthony B. , Vahdati Mehdi
Published: December 2015

The growing pressure to reduce fuel consumption and cut emissions has triggered renewed interest in contra-rotating open rotor (CROR) technologies. One of their potential issues is self-excited or forced vibration of the unducted, light-weight, highly swept blades. This paper presents a numerical study into the flutter behavior of a CROR rig at take-off conditions. The study presented in this paper aimed to validate the numerical approach and provide insights into the flutter mechanisms of the open rotor under investigation. For the initial validation, pressure profiles and thrust coefficients from steady-state mixing plane calculations were compared against rig measurements. A full domain unsteady analysis predicted front rotor instability at low advance ratios. Flutter occurred in the first torsional mode in 0 and 1 nodal diameter (ND) which agreed with experimental observations. Subsequent unsteady computations focused on the isolated front rotor and first torsional mode. The flow field and aerodynamic damping over a range of advance ratios were studied. It was found that minimum aerodynamic damping occurred at low advance ratios when the flow was highly three-dimensional on the suction side. A correlation between the quasi-steady loading on the blade and aeroelastic stability was made and related to the numerical results. The effects of variations in frequency were then investigated by linking local aerodynamic damping to the unsteady pressure on the blade surface.
Single-Cell Migration in Complex Microenvironments: Mechanics and Signaling Dynamics
Authors: Mak Michael , Spill Fabian , Kamm Roger D. , Zaman Muhammad H.
Published: December 2015

Cells are highly dynamic and mechanical automata powered by molecular motors that respond to external cues. Intracellular signaling pathways, either chemical or mechanical, can be activated and spatially coordinated to induce polarized cell states and directional migration. Physiologically, cells navigate through complex microenvironments, typically in three-dimensional (3D) fibrillar networks. In diseases, such as metastatic cancer, they invade across physiological barriers and remodel their local environments through force, matrix degradation, synthesis, and reorganization. Important external factors such as dimensionality, confinement, topographical cues, stiffness, and flow impact the behavior of migrating cells and can each regulate motility. Here, we review recent progress in our understanding of single-cell migration in complex microenvironments.
Type Synthesis of a Family of Novel Four, Five, and Six Degrees-of-Freedom Sea Lion Ball Mechanisms With Three Limbs
Authors: Lin Rongfu , Guo Weizhong , Gao Feng
Published: December 2015

A family of novel mechanisms with three limbs called sea lion ball mechanisms (SLBMs) is investigated that looks like a sea lion playing with a ball. The SLBM-type mechanism is composed of an upper part and a lower part connected together by three limbs in parallel, and the translational and rotational motions are fully/partially decoupled. The end-effector position is determined by inputs of the lower part, while the posture is mainly determined by inputs of the upper part. First, two compositional principles are abstracted and the corresponding mathematical models are built for the SLBM-type mechanisms that the commutative feature of the SLBMs is found. Then, two type synthesis procedures containing five steps are proposed correspondingly. Following the procedure, a family of novel four, five, and six degrees-of-freedom (DOF) SLBM-type mechanisms is synthesized systematically. The motion patterns of the limbs are enumerated according to the given desired ones of the mechanisms and the limbs are synthesized correspondingly. Finally, several novel SLBM-type mechanisms are achieved by assembling the obtained limbs and selecting the actuated joints.
Experimental Validation of Jacobian-Based Stiffness Analysis Method for Parallel Manipulators With Nonredundant Legs
Authors: Hoevenaars Antonius G. L. , Gosselin Clément , Lambert Patrice , Herder Just L.
Published: December 2015

A complete stiffness analysis of a parallel manipulator considers the structural compliance of all elements, both in designed degrees-of-freedom (DoFs) and constrained DoFs, and also includes the effect of preloading. This paper presents the experimental validation of a Jacobian-based stiffness analysis method for parallel manipulators with nonredundant legs, which considers all those aspects, and which can be applied to limited-DoF parallel manipulators. The experimental validation was performed by comparing differential wrench measurements with predictions based on stiffness analyses with increasing levels of detail. For this purpose, two passive parallel mechanisms were designed, namely, a planar 3DoF mechanism and a spatial 1DoF mechanism. For these mechanisms, it was shown that a stiffness analysis becomes more accurate if preloading and structural compliance are considered.
Influence of residual carbon impurities in i-GaN layer on the performance of GaN-based p-i-n photodetectors
Authors: Li Xiaojing , Zhao Degang , Jiang Desheng , Chen Ping , Zhu Jianjun , Liu Zongshun , Le Lingcong , Yang Jing , He Xiaoguang , Zhang Liqun , Zhang Shuming , Liu Jianping , Yang Hui
Published: December 2015

The influence of unintentionally doped carbon impurities of i-GaN layer on the performance of GaN-based p-i-n photodetectors is investigated. The photoluminescence spectra exhibits that the carbon impurities are strongly involved in deep trap level-related yellow luminescence band. The results of secondary ion mass spectroscopy suggest that the residual carbon impurities in the i-layer have great effect on the generation of deep trap levels, and have a strong influence on the spectral responsivity and dark current of photodetectors. Thus, the way to decrease the residual carbon impurity concentration of the i-GaN layer, such as enlarging the growth pressure, can improve the performance of p-i-n photodetectors.
Toward printing molecular nanostructures from microstructured samples in ultrahigh vacuum
Authors: Nacci Christophe , Saywell Alex , Troadec Cedric , Deng Jie , Willinger Marc Georg , Joachim Christian , Grill Leonhard
Published: December 2015

Transferring molecular nanostructures from one surface to another in ultrahigh vacuum (UHV) by mechanical contact might be a possible route to avoid the severe limitations of in situ molecular synthesis on technologically relevant template surfaces. Here, transfer printing in UHV of molecular structures between metal surfaces is investigated by a combination of scanning tunneling microscopy and scanning electron microscopy/energy dispersive x-ray spectroscopy. The authors present the complete procedure of the printing and characterization process. Microstructured Au-coated MoS2 samples exhibiting a periodic pillar structure are used as stamp surfaces with Au(111) single crystals as target surface. Polymers of 1,3,5-tris(4-bromophenyl)benzene molecules and graphene nanoribbons with an armchair edge structure are grown on the pillars of the stamp surface. After bringing the two surfaces in mechanical contact, the transferred material is found on the target while decapping occurs on the stamp surface. Polymer structures are probably buried under the transferred stamp material, and in rare cases, evidence for molecular structures is found in their vicinity.
Low-frequency sound level in the Southern Indian Ocean
Authors: Tsang-Hin-Sun Eve , Royer Jean-Yves , Leroy Emmanuelle C.
Published: December 2015

This study presents long-term statistics on the ambient sound in the Southern Indian Ocean basin based on 2 years of data collected on six widely distributed autonomous hydrophones from 47°S to 4°S and 53°E to 83°E. Daily mean power spectra (10–100 Hz) were analyzed in order to identify the main sound sources and their space and time variability. Periodic signals are principally associated with the seasonal presence of three types of blue whales and fin whales whose signatures are easily identified at specific frequencies. In the low frequencies, occurrence of winter lows and summer highs in the ambient noise levels are well correlated with iceberg volume variations at the southern latitudes, suggesting that icebergs are a major sound source, seasonally contributing to the ambient noise, even at tropical latitudes (26°S). The anthropogenic contribution to the noise spectrum is limited. Shipping sounds are only present north and west of the study area in the vicinity of major traffic lanes. Acoustic recordings from the southern sites may thus be representative of the pristine ambient noise in the Indian Ocean.
Airgun inter-pulse noise field during a seismic survey in an Arctic ultra shallow marine environment
Authors: Guan Shane , Vignola Joseph , Judge John , Turo Diego
Published: December 2015

Offshore oil and gas exploration using seismic airguns generates intense underwater pulses that could cause marine mammal hearing impairment and/or behavioral disturbances. However, few studies have investigated the resulting multipath propagation and reverberation from airgun pulses. This research uses continuous acoustic recordings collected in the Arctic during a low-level open-water shallow marine seismic survey, to measure noise levels between airgun pulses. Two methods were used to quantify noise levels during these inter-pulse intervals. The first, based on calculating the root-mean-square sound pressure level in various sub-intervals, is referred to as the increment computation method, and the second, which employs the Hilbert transform to calculate instantaneous acoustic amplitudes, is referred to as the Hilbert transform method. Analyses using both methods yield similar results, showing that the inter-pulse sound field exceeds ambient noise levels by as much as 9 dB during relatively quiet conditions. Inter-pulse noise levels are also related to the source distance, probably due to the higher reverberant conditions of the very shallow water environment. These methods can be used to quantify acoustic environment impacts from anthropogenic transient noises (e.g., seismic pulses, impact pile driving, and sonar pings) and to address potential acoustic masking affecting marine mammals.
Role of Residues W228 and Y233 in the Structure and Activity of Metallo-β-Lactamase GIM-1
Authors: Skagseth Susann , Carlsen Trine Josefine , Bjerga Gro Elin Kjæreng , Spencer James , Samuelsen Ørjan , Leiros Hanna-Kirsti S.
Published: December 2015

Metallo-β-lactamases (MBLs) hydrolyze virtually all β-lactam antibiotics, including penicillins, cephalosporins, and carbapenems. The worldwide emergence of antibiotic-resistant bacteria harboring MBLs poses an increasing clinical threat. The MBL German imipenemase-1 (GIM-1) possesses an active site that is narrower and more hydrophobic than the active sites of other MBLs. The GIM-1 active-site groove is shaped by the presence of the aromatic side chains of tryptophan at residue 228 and tyrosine at residue 233, positions where other MBLs harbor hydrophilic residues. To investigate the importance of these two residues, eight site-directed mutants of GIM-1, W228R/A/Y/S and Y233N/A/I/S, were generated and characterized using enzyme kinetics, thermostability assays, and determination of the MICs of representative β-lactams. The structures of selected mutants were obtained by X-ray crystallography, and their interactions with β-lactam substrates were modeled
in silico
. Steady-state kinetics revealed that both positions are important to GIM-1 activity but that the effects of individual mutations vary depending on the β-lactam substrate. Activity against type 1 substrates bearing electron-donating C-3/C-4 substituents (cefoxitin, meropenem) could be enhanced by mutations at position 228, whereas hydrolysis of type 2 substrates (benzylpenicillin, ampicillin, ceftazidime, imipenem) with methyl or positively charged substituents was favored by mutations at position 233. The crystal structures showed that mutations at position 228 or the Y233A variant alters the conformation of GIM-1 loop L1 rather than that of loop L3, on which the mutations are located. Taken together, these data show that point mutations at both positions 228 and 233 can influence the catalytic properties and the structure of GIM-1.
Immunomodulatory Role of Clarithromycin in Acinetobacter baumannii Infection via Formation of Neutrophil Extracellular Traps
Authors: Konstantinidis Theocharis , Kambas Konstantinos , Mitsios Alexandros , Panopoulou Maria , Tsironidou Victoria , Dellaporta Erminia , Kouklakis Georgios , Arampatzioglou Athanasios , Angelidou Iliana , Mitroulis Ioannis , Skendros Panagiotis , Ritis Konstantinos
Published: December 2015

Macrolide antibiotics have been shown to act as immunomodulatory molecules in various immune cells. However, their effect on neutrophils has not been extensively investigated. In this study, we investigated the role of macrolide antibiotics in the generation of neutrophil extracellular traps (NETs). By assessing
ex vivo
and
in vivo
NET formation, we demonstrated that clarithromycin is able to induce NET generation both
in vitro
and
in vivo
. Clarithromycin utilizes autophagy in order to form NETs, and these NETs are decorated with antimicrobial peptide LL-37. Clarithromycin-induced NETs are able to inhibit
Acinetobacter baumannii
growth and biofilm formation in an LL-37-dependent manner. Additionally, LL-37 antimicrobial function depends on NET scaffold integrity. Collectively, these data expand the knowledge on the immunomodulatory role of macrolide antibiotics via the generation of LL-37-bearing NETs, which demonstrate LL-37-dependent antimicrobial activity and biofilm inhibition against
A. baumannii
.