bluuebunny/crossref_metadata_2025 huggingface dataset:
“I Like it!” Preference Actions Separated from Hedonic Reactions
Authors: Booth David A.
Published: March 2016

In 1952–1957, Peryam and colleagues developed nine ordinal phrases of liking and dislike to assess consumers' dispositions to accept or reject a food or drink. They named their questionnaire a Food Preference Scale. Others called it the Hedonic Scale, which means assessment of pleasure, not choice. It is still widely assumed that the word “like” distinguishes felt pleasure from observed wanting to consume the sample. The quantitative results presented here complement an earlier qualitative finding that preference scores do not provide evidence of the experiencing of pleasure. Rather, “I like it!” simply indicates high acceptance of the sampled variant of a product. Nevertheless, in this experiment, some assessors did also get a convulsive thrill from oral stimulation, as distinct from just enjoying the mouthful, or being pleased by it. However, this sensual pleasure came only from strongly disliked levels of stimulation and is probably unique to samples sensed as intensely sweet.

Practical Applications

This experiment's separation of preference from pleasure depended on overcoming practitioners' division between sensory vocabulary and preference scores. Instead of seeking statistical patterns that bridge the supposed gap between sensory concepts and acts of acceptance, sensory studies should design test samples capable of measuring the impact of specified variations in the product range, first on a fully integrative judgment such as match to the personal ideal, or to the most familiar or usual brand. Second, if analytical characterization might help to test the specification, samples can be rated on vocabulary learned in life or in the laboratory, with one anchor on the standard to be matched, such “exactly as I like it” or “just right” (not “like extremely” or “just about right”), and only one other anchor, such as “neither like nor dislike” or “just too wrong to be tolerable.” Existing data collection and analysis software are easily adapted this way.
Morphology of congenital portosystemic shunts involving the left colic vein in dogs and cats
Authors: White R. N. , Parry A. T.
Published: March 2016

OBJECTIVE

To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats.

METHODS

Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required.

RESULTS

Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication.

CLINICAL SIGNIFICANCE

The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery.
The good, the bad, and the ugly: which Australian terrestrial mammal species attract most research?
Authors: Fleming Patricia A. , Bateman Philip W.
Published: March 2016

The Australian mammalian fauna is marked by high endemism and evolutionary distinctiveness and comprises monotreme, marsupial, and eutherian (‘placental’) native species. It has suffered the highest extinction rate of any mammalian fauna in any global region; surviving species are threatened by competition and predation from a range of introduced mammal species, and receive low levels of conservation‐oriented funding compared with species in many other countries.

We investigated research foci on this unique fauna by using species h‐indices (SHI), and identified both taxonomic bias and subject bias in research effort and research impact for 331 Australian terrestrial mammal species. Species broadly fell into categories we labelled as the ‘good’, the ‘bad’, and the ‘ugly’.

The majority of studies on monotremes and marsupials (the ‘good’) are directed towards their physiology and anatomy, with a smaller ecological focus. By contrast, introduced eutherians (the ‘bad’) have attracted greater attention in terms of ecological research, with greater emphasis on methods and technique studies for population control. Despite making up 45% of the 331 species studied, native rodents and bats (the ‘ugly’) have attracted disproportionately little study.

While research on invasive species is directed towards problem solving, many Australian native species of conservation significance have attracted little research effort, little recognition, and little funding. Current global and national conservation funding largely overlooks non‐charismatic species, and yet these species may arguably be most in need of scientific and management research effort.
Cold curation of pristine astromaterials: Insights from the Tagish Lake meteorite
Authors: Herd Christopher D. K. , Hilts Robert W. , Skelhorne Aaron W. , Simkus Danielle N.
Published: March 2016

The curation and handling of volatile‐bearing astromaterials is of prime importance in current and future plans for sample return missions to targets containing organic compounds, ices, or other volatile components. We report on the specific curation constraints required for the preservation of the Tagish Lake meteorite, a C2 ungrouped chondrite that contains significant concentrations of organic matter, including compounds of prebiotic interest or volatile in character, and which was recovered from a frozen lake surface a few days after its fall. Here, we review the circumstances of the meteorite's handling, its complement of intrinsic and contaminant organic compounds, and an unusual reaction between some of the specimens and the Al foil in which they were enclosed. From our results, we derive the requirements for curation of the meteorite, and describe a specialized facility that enables its curation and handling. The Subzero Facility for Curation of Astromaterials consists of a purified Ar glove box enclosed within a freezer chamber, and enables investigations relevant to curation of samples at or below −10 °C. We provide several recommendations based on insights obtained from the commissioning and initial use of the facility that are relevant to collection of freshly fallen meteorites, curation of volatile‐bearing meteorites and other astromaterials, and planning and implementation of curation plans for future sample return missions to volatile‐bearing targets.
Private Versus Public Sector Wage Gap: Does Origin Matter?
Authors: Berson Clémence
Published: March 2016

The integration of immigrants and their children is a burning issue in France. Governments mainly build their integration policies on the labour market. The public sector is reputed to better assimilate minorities because of its entrance exams and pay scales. In this article, using a switching model, a comparison of the public and private sectors shows that second‐generation immigrants are not treated equally in both sectors. A wage gap is observed between workers of French origin and those of Southern European origin. The wage differential between workers of French and North African origins is mostly explained by observable variables.
The putative phospholipase Lip2 counteracts oxidative damage and influences the virulence of Ustilago maydis
Authors: Lambie Scott C. , Kretschmer Matthias , Croll Daniel , Haslam Tegan M. , Kunst Ljerka , Klose Jana , Kronstad James W.
Published: March 2016

Ustilago maydis is an obligate biotrophic fungal pathogen which causes common smut disease of corn. To proliferate in host tissue, U. maydis must gain access to nutrients and overcome plant defence responses, such as the production of reactive oxygen species. The elucidation of the mechanisms by which U. maydis meets these challenges is critical for the development of strategies to combat smut disease. In this study, we focused on the contributions of phospholipases (PLs) to the pathogenesis of corn smut disease. We identified 11 genes encoding putative PLs and characterized the transcript levels for these genes in the fungus grown in culture and during infection of corn tissue. To assess the contributions of specific PLs, we focused on two genes, lip1 and lip2, which encode putative phospholipase A2 (PLA2) enzymes with similarity to platelet‐activating factor acetylhydrolases. PLA2 enzymes are known to counteract oxidative damage to lipids in other organisms. Consistent with a role in the mitigation of oxidative damage, lip2 mutants were sensitive to oxidative stress provoked by hydrogen peroxide and by increased production of reactive oxygen species caused by inhibitors of mitochondrial functions. Importantly, mutants defective in lip2, but not lip1, were attenuated for virulence in corn seedlings. Finally, a comparative analysis of fatty acid and cardiolipin profiles in the wild‐type strain and a lip2 mutant revealed differences consistent with a protective role for Lip2 in maintaining lipid homeostasis and mitochondrial health during proliferation in the hostile host environment.
Peroxisomal fission is induced during appressorium formation and is required for full virulence of the rice blast fungus
Authors: Chen Xiao‐Lin , Shen Mi , Yang Jun , Xing Yunfei , Chen Deng , Li Zhigang , Zhao Wensheng , Zhang Yan
Published: March 2016

Peroxisomes are involved in various metabolic processes and are important for virulence in different pathogenic fungi. How peroxisomes rapidly emerge in the appressorium during fungal infection is poorly understood. Here, we describe a gene, PEF1, which can regulate peroxisome formation in the appressorium by controlling peroxisomal fission, and is required for plant infection in the rice blast fungus Magnaporthe oryzae. Targeted deletion of PEF1 resulted in a reduction in virulence and a delay in penetration and invasive growth in host cells. PEF1 was particularly expressed during appressorial development, and its encoding protein was co‐localized with peroxisomes during appressorial development. Compared with the massive vesicle‐shaped peroxisomes formed in the wild‐type appressorium, the Δpef1 mutant could only form stringy linked immature peroxisomes, suggesting that PEF1 was involved in peroxisomal fission during appressorium formation. We also found that the Δpef1 mutant could not utilize fatty acids efficiently, which can improve significantly the expression level of PEF1 and induce peroxisomal fission. As expected, the Δpef1 mutant showed reduced intracellular production of reactive oxygen species (ROS) during appressorium formation and induced ROS accumulation in host cells during infection. Taken together, PEF1‐mediated peroxisomal fission is important for fungal infection by controlling the number of peroxisomes in the appressorium.
OPTIMAL HARVESTING AND SPATIAL PATTERNS IN A SEMIARID VEGETATION SYSTEM
Authors: UECKER HANNES
Published: March 2016

We consider an infinite time horizon spatially distributed optimal harvesting problem for a vegetation and soil water reaction diffusion system, with rainfall as the main external parameter. By Pontryagin's maximum principle, we derive the associated four‐component canonical system (CS), and numerically analyze this and hence the optimal control problem in two steps. First, we numerically compute a rather rich bifurcation structure of flat (spatially homogeneous) canonical steady states and patterned canonical steady states (FCSS and PCSS, respectively), in 1D and 2D. Then, we compute time‐dependent solutions of the CS that connect to some FCSS or PCSS. The method is efficient in dealing with nonunique canonical steady states, and thus also with multiple local maxima of the objective function. It turns out that over wide parameter regimes the FCSS, i.e., spatially uniform harvesting, are not optimal. Instead, controlling the system to a PCSS yields a higher profit. Moreover, compared to (a simple model of) private optimization, the social control gives a higher yield, and vegetation survives for much lower rainfall. In addition, the computation of the optimal (social) control gives an optimal tax to incorporate into the private optimization.
Berliner Mauerfall und Grenzüberschreitungen im urbanen Raum
Authors: Ege Müzeyyen
Published: March 2016

Literarische Großstadtschilderungen können als diskursive Stadtansichten analysiert werden, denen eine spezifische Funktion für Prozesse der Identitätsbildung und ‐auflösung zukommt. Mit seiner wechselvollen Geschichte bietet das multikulturelle Berlin mit dem Mauerfall und der Wende einen Schauplatz vielfältiger Übergänge. Zur Aufarbeitung der Wiedervereinigung und der dadurch erneut in das Bewusstsein eingebrochenen Vergangenheit reagierten zahlreiche deutschsprachige Autoren mit der „Wendeliteratur“. Der urbane Raum stellt hierbei einen imaginären Erzählraum in einer „postmigrantischen“ Gesellschaft dar, in der die Auflösung der Mauer als topographische wie auch historisch‐politische Grenze die Protagonisten auch mit persönlichen Grenzen konfrontiert. Die Mauer selbst tritt damit als sich wiederholende Metapher der Grenze oder Schwelle in den beiden im vorliegenden Beitrag untersuchten „Wenderomanen“ der Autoren Yadé Kara und Peter Schneider auf, die daraufhin befragt werden, inwiefern Berlin den Protagonisten als polyvalenter Raum des Wandels und der Übergänge und damit als Projektionsfläche für eigene Transformationsprozesse und Identitätsenwürfe dient und welche Narrative dafür verwendet werden.
Selectivity of conditioned fear of touch is modulated by somatosensory precision
Authors: Harvie Daniel S. , Meulders Ann , Reid Emily , Camfferman Danny , Brinkworth Russell S. A. , Moseley G. Lorimer
Published: March 2016

Learning to initiate defenses in response to specific signals of danger is adaptive. Some chronic pain conditions, however, are characterized by widespread anxiety, avoidance, and pain consistent with a loss of defensive response specificity. Response specificity depends on ability to discriminate between safe and threatening stimuli; therefore, specificity might depend on sensory precision. This would help explain the high prevalence of chronic pain in body areas of low tactile acuity, such as the lower back, and clarify why improving sensory precision may reduce chronic pain. We compared the acquisition and generalization of fear of pain‐associated vibrotactile stimuli delivered to either the hand (high tactile acuity) or the back (low tactile acuity). During acquisition, tactile stimulation at one location (CS+) predicted the noxious electrocutaneous stimulation (US), while tactile stimulation at another location (CS−) did not. Responses to three stimuli with decreasing spatial proximity to the CS+ (generalizing stimuli; GS1–3) were tested. Differential learning and generalization were compared between groups. The main outcome of fear‐potentiated startle responses showed differential learning only in the hand group. Self‐reported fear and expectancy confirmed differential learning and limited generalization in the hand group, and suggested undifferentiated fear and expectancy in the back group. Differences in generalization could not be inferred from the startle data. Specificity of fear responses appears to be affected by somatosensory precision. This has implications for our understanding of the role of sensory imprecision in the development of chronic pain.
Modeling fear‐conditioned bradycardia in humans
Authors: Castegnetti Giuseppe , Tzovara Athina , Staib Matthias , Paulus Philipp C. , Hofer Nicolas , Bach Dominik R.
Published: March 2016

Across species, cued fear conditioning is a common experimental paradigm to investigate aversive Pavlovian learning. While fear‐conditioned stimuli (CS+) elicit overt behavior in many mammals, this is not the case in humans. Typically, autonomic nervous system activity is used to quantify fear memory in humans, measured by skin conductance responses (SCR). Here, we investigate whether heart period responses (HPR) evoked by the CS, often observed in humans and small mammals, are suitable to complement SCR as an index of fear memory in humans. We analyze four datasets involving delay and trace conditioning, in which heart beats are identified via electrocardiogram or pulse oximetry, to show that fear‐conditioned heart rate deceleration (bradycardia) is elicited and robustly distinguishes CS+ from CS−. We then develop a psychophysiological model (PsPM) of fear‐conditioned HPR. This PsPM is inverted to yield estimates of autonomic input into the heart. We show that the sensitivity to distinguish CS+ and CS− (predictive validity) is higher for model‐based estimates than peak‐scoring analysis, and compare this with SCR. Our work provides a novel tool to investigate fear memory in humans that allows direct comparison between species.
A log‐normal spectral analysis of inorganic grain‐size distributions from a Canadian boreal lake core: Towards refining depositional process proxy data from high latitude lakes
Authors: Gammon Paul R. , Neville Lisa A. , Patterson R. Timothy , Savard Martine M. , Swindles Graeme T.
Published: March 2016

Better methods for interpreting grain‐size spectra will enhance current understanding of past transport–depositional processes. A high‐resolution inorganic grain‐size dataset has been measured from a freeze core extracted from ‘Alberta Lake E’ a boreal fresh water lake 40 km east of the Athabasca Oil Sands in north‐eastern Alberta, Canada. The grain‐size spectra are remarkably consistent throughout the core, exhibiting a structure comprising six persistent grain‐size distributions below ca 250 μm, plus a rare medium‐sand distribution. Automated deconvolution of the grain‐size spectra produced poor results. Constraining the modes of two of the distributions produced deconvolution solutions that were statistically excellent and consistent with the structure of each spectrum. Statistical analysis of the ‘constrained’ solutions indicates that deconvolution successfully extracted independent grain‐size populations. Conversely, the multimodal spectra generate traditional measures (for example, mean grain size) that are inconsistent combinations of different individual populations and thus are poor proxies of transport–depositional processes. Alberta Lake E is situated in a boreal wetland landscape where sediment delivery is dominated by overland flow transport during spring melt. This context means that the Alberta Lake E grain‐size spectra can be interpreted to reflect: (i) a bedload component transported during short‐duration high discharge events that reflect the intensity of the melt; and (ii) a finer suspended load component representing material whose magnitude is controlled by the volume of the spring melt. Stratigraphically, bedload and suspended load populations demonstrate different short‐wavelength and long‐wavelength cyclicity, suggesting that spring melt is likely to be driven by cyclic external forcing factors. The links between the grain‐size spectra and spring melt have potential for generating proxy records that better capture the external controls over spring melt in boreal systems and the risks associated with these energetic hydrodynamics. This is exemplified by the coarsest Alberta Lake E distributions, which indicate that more intense spring‐melt dynamics occurred in pre‐historical times.
Biases in Attention for Social Stimuli in Children are Associated with Patterns of Infant Attachment: A Brief Report
Authors: Meinz Paul , Morton J. Bruce , Pederson David R. , Moran Greg
Published: March 2016

The way an individual attends to social information has implications for his/her ability to regulate behavior in social settings. The results of the present investigation suggest that early experiences in parent–child relationships contribute to later differences in the deployment of attention to social information. The quality of the mother–child relationship was assessed at one‐year‐of‐age. At seven to eight years of age, a dot‐probe paradigm assessed immediate and delayed attention to pictures of faces vs. pictures of neutral objects. Children who were more avoidant with their mother in infancy attended to neutral objects over social stimuli at delayed but not immediate time frames. This finding suggests that individual differences in attention to social stimuli in childhood are associated with the quality of the prior attachment relationship with a primary caregiver.
On Crack Detection in Tuned and Mistuned Repeating Structures Using the Modal Assurance Criterion
Authors: Rehman A. U. , Worden K. , Rongong J. A.
Published: March 2016

Repeating structures in the form of multiple‐bladed rotors are used widely in turbomachinery. Mistuning in turbomachinery is caused by small differences in individual blade properties because of inevitable material and manufacturing variations, resulting in the splitting of vibration modes of the tuned system. Modal characteristics of the blades are quite sensitive to the level of mistuning present inside the structure. In addition, the existence of damage also results in changed dynamics of the complete system. This paper introduces a modal assurance criterion (MAC)‐based approach for the investigation of small defects such as cracks in a repeating structure. In order to understand the key issues involved, initial work involved a numerical study of a simple comb‐like repeating structure, followed by a detailed numerical and experimental investigation of a tuned and mistuned bladed disc. Changes to the system mode shapes and mode order arising from damage are related to the location and severity of damage. Damage, in the form of small, open cracks, is modelled using different techniques such as follows: material removal, monotonic reduction in the modulus of elasticity of selected elements at the required location and mass modification. Damage indices based on differences in the MAC that give a measure of the change in the mode shapes are introduced. MAC matrices are obtained using a reduced number of data points. The damage index is obtained from the Frobenius norm of the MAC matrix subtracted from the AutoMAC of a reference tuned model without crack. A clear correlation between the damage indices and the crack depth/location is shown. Application of this approach to the limited data obtainable from developing techniques such as blade tip timing is also explained.
Effects of unplanned treatment interruptions on HIV treatment failure – results from TAHOD
Authors: Jiamsakul Awachana , Kerr Stephen J. , Ng Oon Tek , Lee Man Po , Chaiwarith Romanee , Yunihastuti Evy , Van Nguyen Kinh , Pham Thuy Thanh , Kiertiburanakul Sasisopin , Ditangco Rossana , Saphonn Vonthanak , Sim Benedict L. H. , Merati Tuti Parwati , Wong Wingwai , Kantipong Pacharee , Zhang Fujie , Choi Jun Yong , Pujari Sanjay , Kamarulzaman Adeeba , Oka Shinichi , Mustafa Mahiran , Ratanasuwan Winai , Petersen Boondarika , Law Matthew , Kumarasamy Nagalingeswaran ,   the TREAT Asia HIV Observational Database (TAHOD)
Published: March 2016

Objectives

Treatment interruptions (TIs) of combination antiretroviral therapy (cART) are known to lead to unfavourable treatment outcomes but do still occur in resource‐limited settings. We investigated the effects of TI associated with adverse events (AEs) and non‐AE‐related reasons, including their durations, on treatment failure after cART resumption in HIV‐infected individuals in Asia.

Methods

Patients initiating cART between 2006 and 2013 were included. TI was defined as stopping cART for >1 day. Treatment failure was defined as confirmed virological, immunological or clinical failure. Time to treatment failure during cART was analysed using Cox regression, not including periods off treatment. Covariables with P < 0.10 in univariable analyses were included in multivariable analyses, where P < 0.05 was considered statistically significant.

Results

Of 4549 patients from 13 countries in Asia, 3176 (69.8%) were male and the median age was 34 years. A total of 111 (2.4%) had TIs due to AEs and 135 (3.0%) had TIs for other reasons. Median interruption times were 22 days for AE and 148 days for non‐AE TIs. In multivariable analyses, interruptions >30 days were associated with failure (31–180 days HR = 2.66, 95%CI (1.70–4.16); 181–365 days HR = 6.22, 95%CI (3.26–11.86); and >365 days HR = 9.10, 95% CI (4.27–19.38), all P < 0.001, compared to 0–14 days). Reasons for previous TI were not statistically significant (P = 0.158).

Conclusions

Duration of interruptions of more than 30 days was the key factor associated with large increases in subsequent risk of treatment failure. If TI is unavoidable, its duration should be minimised to reduce the risk of failure after treatment resumption.
Clinically significant anti‐KEL RBC alloantibodies are transferred by breast milk in a murine model
Authors: Santhanakrishnan M. , Tormey C. A. , Natarajan P. , Liu J. , Hendrickson J. E.
Published: March 2016

Background and Objectives

Fetuses affected by maternal RBC alloantibodies may have prolonged anaemia after birth, leading one to question whether maternal alloantibody transfer may occur outside the placenta. In response to a recent publication describing breast milk transfer of clinically significant amounts of maternal antiplatelet IgA antibodies from mother to nursing infant, we hypothesized that maternal RBC alloantibodies may also be capable of being transferred in breast milk.

Materials and Methods

The presence and clinical significance of breast milk alloantibody transfer were tested through a series of pregnancy, fostering and transfusion experiments, using a murine model in which transgenic RBCs express the human KEL glycoprotein.

Results

Maternal anti‐KEL immunoglobulins, induced through transfusion or pregnancy, were detected in the aqueous phase of breast milk. Further, efficient transfer of maternal anti‐KEL IgG and IgA to nursing pups was observed in fostering experiments. The breast milk‐acquired alloantibodies were clinically significant in wild‐type pups in a transfusion setting, binding to ‘incompatible’ KEL RBCs and leading to premature clearance from the circulation. Although breast milk‐acquired alloantibodies also bound to the RBCs of transgenic KEL‐positive fostered pups, no anaemia resulted.

Conclusions

Taking these murine data in combination with recently published human data of maternal antiplatelet IgA antibodies in breast milk leading to sequelae in some infants, it is theoretically possible that maternal anti‐RBC IgA alloantibodies may also be transferred in human breast milk and may lead to sequelae in some infants under some circumstances.
Manufacturing of High-Performance Nano/Microcellular Expanded PLA Bead Foams
Authors: Nofar Mohammadreza , Park Chul B.
Published: March 2016

In this study, expanded polylactide (EPLA) bead foams were produced with cellular morphology ranging from nanocellular to microcellular. This was achieved by using bead foaming technology while a double crystal melting peak structure was generated. The high melting peak crystals generated during the gas saturation played an important role on controlling the cell size and expansion ratio of the foamed beads. As the amount of high melting peak crystals increased, the cell sizes were reduced to around 350 nm while the expansion ratio was around 3-fold. In other words, the induced perfected crystals significantly promoted the heterogeneous cell nucleation while hindering the cell growth. On the other hand, with the reduced amount of these perfected crystals, the cell sizes were increased to around 15 μm and the expansion ratio of the foamed beads increased to 30-fold.
Instability of H2-O2-CO2 Premixed Flames on Flat Burner
Authors: Kaewpradap Amornrat , Kadowaki Satoshi
Published: March 2016

As the greenhouse emission problems, the combustion of hydrogen-air (H2-air) mixtures was investigated to consider the reduction of carbon dioxide (CO2) and the replacement of nitrogen N2 with CO2 was studied to reduce nitrogen oxide (NOx). Normally, the flame speed of H2-O2 mixtures is very fast thus it is necessary to control the limit of mixtures with CO2 addition as H2-O2-CO2 combustion. The limit of hydrogen was set and replaced by CO2 with O2:CO2 ratio as 1:3, 1:3.76 and 1:4 for this study. In this study, the combustion of H2-O2 -CO2 on flat burner at equivalence ratio ϕ=0.5 was investigated for 10, 15 and 20 L/min of flow rate of mixtures. When the ratio of CO2 increases, the power spectral density is lower, the ring of attractor is more complicated and the cellular flame become larger because the decrease of hydrogen replaced by CO2 affects the diffusive-thermal instability. Moreover, as the flow rate of mixtures increases, the power spectral density increases, and the reconstructed attractor and cell size become smaller due to decreasing of instability. The results show that the variation of CO2 and the flow rate of mixtures affect the instability of cellular premixed flames on flat burner.
Analysis of Formation of the Critical State in Tensile Failure of Unidirectional Composites
Authors: Zhuang Linqi , Talreja Ramesh
Published: March 2016

Unidirectional (UD) composites are building blocks in most load bearing structural components for lightweight applications in aerospace, automotive and wind energy industries. The loss of the structural load bearing capacity is governed by the instability of the fiber breakage process in the UD composites. When subjected to increasing or repeated tensile loading along fiber direction, the first failure event within these composites occurs as discrete fibers break at weak points followed by fiber/matrix debonding due to high stress concentration caused by fiber breaks. Upon further loading, or on repeated loading, more fiber breaks occur along with other accumulated damage events such as debond growth and matrix cracking. Final failure of a UD composite occurs when a critical fracture plane is formed by interconnecting individual broken fibers and associated debonding through matrix cracking. This failure process has emerged from numerous experimental studies, which also suggest that the critical fracture plane contains only a small number of broken fibers for commonly used composites such as glass/epoxy and carbon/epoxy. However, the mechanisms underlying the critical fracture plane formation are not clear. As the first step to clarify the creation of a critical fracture plane, the conditions for connectivity of a broken fiber end with neighboring broken fibers is studied in this work. In order to investigate the local stress field surrounding the broken fiber, a finite element (FE) model is constructed in which six neighboring fibers are placed as a ring of concentric axisymmetric cylinder embedded in the matrix. The discrete fiber region is surrounded by a concentric outer cylinder ring of homogenized composite. The entire FE model is subjected to axial tensile loading. To account for the consequence of the stress enhancement at the broken fiber end, a debond crack at the fiber/matrix interface extending a short distance from the fiber end is included in the analysis. Realizing that the debond crack by itself would not connect with other fiber failures, focus of the stress and failure analysis is placed on deviation of the debond crack laterally into the matrix. For this purpose, matrix cracking in two possible modes — ductile and brittle — is considered, Energy based criteria are used to study the competition between the cracking modes and the crack path into the matrix from the end of debond to the neighboring fibers is determined. Next the failure of the neighboring fibers caused by the intense stress field accompanying the matrix cracks is studied. The conditions for generating a plane connecting the initially broken fiber end to subsequent fiber failures are finally determined. Further ongoing studies are aimed at clarifying the limiting conditions for avoiding the fiber failure criticality, and thereby improving the load bearing capacity of UD composites. The statistical considerations regarding fiber failure will also be incorporated in these studies.
Study on Periodic Thermal-Switching Behavior of Flat Heat Pipe
Authors: Hirasawa Shigeki , Nakamu Tatsuya , Kawanami Tsuyoshi , Shirai Katsuaki
Published: March 2016

The coupling of the electrocaloric effect in thin films with thermal switches has the potential to be used for efficient refrigeration. We studied the unsteady heat transfer performance and periodic thermal-switching behavior of a flat heat pipe to transfer cold energy from a changing heat source. The condenser of the flat heat pipe was the changing heat source and changed from −20 W to +20 W every 5 s. The temperature of the condenser surface changed in accordance with the heat generation of the heat source. The evaporator was a plate with a mesh wick attached to a water-flow pipe. Cold energy transferred from the condenser surface to the evaporator surface only when the temperature of the condenser surface was lower than that of the evaporator surface. We analyzed the unsteady temperature change and heat transfer performance of the flat heat pipe by numerical simulation. The analytical results showed that it was necessary to have two thermal switches to separate the heat energy and cold energy of the changing heat source. Also, it was important to reduce the thermal resistance and heat capacity of the evaporator surface to improve the unsteady heat transfer performance of the heat pipe. Next, we measured the unsteady heat transfer performance of the flat heat pipe experimentally. The experimental results showed that the thermal-switching behavior was observed when the heat generation of the heat source changed every 5 s.
Enabling Right-Provisioned Microprocessor Architectures for the Internet of Things
Authors: Adegbija Tosiron , Rogacs Anita , Patel Chandrakant , Gordon-Ross Ann
Published: March 2016

The Internet of Things (IoT) consists of embedded low-power devices that collect and transmit data to centralized head nodes that process and analyze the data, and drive actions. The proliferation of these connected low-power devices will result in a data explosion that will significantly increase data transmission costs with respect to energy consumed and latency. Edge computing performs computations at the edge nodes prior to data transmission to interpret and/or utilize the data, thus reducing transmission costs. In this work, we seek to understand the interactions between IoT applications’ execution characteristics (e.g., compute/memory intensity, cache miss rates, etc.) and the edge nodes’ microarchitectural characteristics (e.g., clock frequency, memory capacity, etc.) for efficient and effective edge computing. Thus, we present a broad and tractable IoT application classification methodology and using this classification, we analyze the microarchitectural characteristics of a wide range of state-of-the-art embedded system microprocessors and evaluate the microprocessors’ applicability to IoT computation using various evaluation metrics. We also investigate and quantify the impact of leakage power reduction on the overall energy consumption across different architectures. Our work provides insights into the microarchitectural characteristics’ impact on system performance and efficiency for various IoT application requirements. Our work also provides a foundation for the analysis and design of a diverse set of microprocessor architectures for IoT edge computing.
Automatic Identification of Genu Valgum From Tibio-Femoral Short Radiographs
Authors: Nájera-Olvera Pedro Antonio , Menon Prahlad G.
Published: March 2016

Genu valgum is a cause of knee pain and early arthritis which requires therapeutic action with external braces or surgery at a young age. This paper describes an image processing workflow and validation study for automatic characterization of the valgus deformity (i.e. genu valgum) from tibio-femoral x-ray radiographs. We implement an image processing pipeline starting with basic filtering and bone segmentation, followed by application of a Hough transform to determine the centerline of the diaphyses of the femur and tibia based on which a TF subtended angle is measured for each leg. Feasibility of this workflow is demonstrated on 21 short TF radiographs. The automatically computed angles were highly correlated (r2 = 0.85 and p≪0.001) to the ground truth with a mean absolute error as low as 1.97°.
Tribological Behavior of Carbon Based Materials
Authors: Özmen Yılmaz
Published: March 2016

Diamond-like carbon (DLC) films have excellent tribological properties. These include low friction, high wear resistance, high corrosion resistance, and a high anti-seizure resistance. DLC film with and without Si doping (due to its promising effect on friction coefficient), at approximately 1–2 μm thickness, was synthesized by a reactive ion plating method using C6H6 source on WC-Co substrate. Si addition on tribological properties of DLC was evaluated. The effects of relative humidity and contact load are also investigated. When the Si content was increased above 5.9 at. %, tribological properties of the coating were deteriorated. These properties are, however, affected by film deposition parameters and sliding conditions such as normal load, sliding speed, mating materials, and atmospheric conditions. The effect of environment is particularly significant.
Effect of Particle Morphology on Pool Boiling From Surfaces Coated With Sintered Particles
Authors: Sarangi Suchismita , Weibel Justin A. , Garimella Suresh V.
Published: March 2016

Immersion cooling strategies often employ surface enhancements to improve the pool boiling heat transfer performance. Sintered particle/powder coatings with different constituent particle sizes and total layer thicknesses have been commonly used on smooth surfaces to reduce the wall superheat and increase the critical heat flux during pool boiling. However, the role of the particle morphology on pool boiling has not been explicitly investigated. Since the morphology of the particles affects the pore shape, permeability, surface roughness, effective conductivity and diffusivity of the sintered coating, it will impact the heat transfer coefficient and critical heat flux during boiling. In this study, pool boiling of FC-72 is experimentally investigated using copper surfaces coated with a layer of sintered copper particles of irregular, dendritic and spherical morphologies. In order to isolate the effect of particle morphology, particles with the same effective diameter (90–106 μm) are sintered under controlled conditions that yield the same porosity (∼60%) and coating thickness (∼6 particle diameters) for all samples tested. The effects of particle morphology on the incipient wall superheat, nucleate boiling heat transfer coefficient, and critical heat flux are analyzed. The morphology of the pore structure in the coating formed by sintering is observed with SEM images; bubble nucleation and departure characteristics affecting the heat transfer performance of the coatings are qualitatively assessed with the aid of high-speed flow visualizations to corroborate the trends observed in the boiling curves. The irregular particles are observed to show the highest heat transfer coefficient, followed by dendritic and then spherical particles. The critical heat flux is found to be independent of the particle morphology.
Experimental Study of High Velocity Penetration of an Aluminum Target Plate by a Spherical Projectile
Authors: Liu Yucheng , Dou Yangqing , Justin Warren , Horstemeyer Stephen J. , Thirumalai Rooban V. K. G. , Williams William
Published: March 2016

A high velocity penetration experimental between an aluminum sphere and a square aluminum plate is carried out to provide data for depicting the penetration process and behavior of both projectile and target at multi-length scales. Residual stress patterns of the plate’s surface before and after penetration are recorded and compared through X-ray diffraction (XRD). Effects of the penetration on microstructure of the Al plate and the material’s microstructural evolution are also illustrated through SEM. Important Physical features of the penetration phenomena are observed from the penetration tests. A good understanding of Al-Al penetration mechanism can therefore be achieved from the experimental study, along which a standard experimental procedure can be established for investigating plasticity mechanisms that govern engineering material penetration.
Tolerance Simulation of Thin-Walled C-Section Composite Beam in Wingbox Assembly Under Preloading
Authors: Wang Hua , Liu Jun
Published: March 2016

Tolerance simulation’s reliability depends on the concordance between the input probability distribution and the practical situation. Pre-loading induced changes in the probability distribution should be considered in the structure’s tolerance simulation, especially for composite structures. The paper presents a tolerance simulation method for the thin-walled C-section composite beam (TC2B) assembling under preloading, that is prescribed clamping force. Based on FEA model of TC2B, the preloading-modified probability distribution function of the R angle spring-in deviation is proposed. Thickness variations of the TC2B are obtained from the data of the downscaled composite wingbox. These parts’ variations are input to the tolerance simulation software, and the final assembly variations are obtained. The assembly of the downscaled wingbox illustrates the effect of preloading on the probability distribution of the R angle spring-in deviation. The results have shown that tolerance simulation with the modified probability distribution is more accurate than the initial normal distribution. The tolerance simulation work presented in the paper will enhance the understanding of the composite parts assembling with spring-in deviations, and help systematically improving the precision control efficiency in civil aircraft industry.
Development of Self Regulation Skills and Academic Self-Efficacy Beliefs
Authors: Shih Hui-Ru , Zheng Wei , Yuan Pao-Chiang , Ford Richterica Tukiya
Published: March 2016

In engineering and technology education, increasing concerns about student retention have led educators to pursue possible explanations for students’ academic successes and failures. Educators need to maintain students’ learning interest and motivation and increase their self-efficacy and learning persistence. Self-Regulated Learning (SRL) is a specific form of learning. “Self-regulated” describes a process of taking control of and evaluating one’s own learning and behavior. SRL is guided by meta-cognition, strategic action, and motivation to learn. With SRL, students can evaluate their study and learning strategies. Self-regulated learners also hold incremental beliefs about intelligence and attribute their successes or failures to factors within their control. The application of self-regulation to learning is a complicated process involving not only the awareness and application of learning strategies but also extensive reflection and self-awareness. Training programs that promote SRL have been found to be beneficial for students’ learning. This paper describes the design and development of the SRL instructional strategies, their implementation, and the evaluation of their effectiveness. Students also learned about the brain and how it forms new connections every time they learn something new. The outcomes are provided and recommendations are discussed.
New Prototype of the Two-Legged Robot CENTAUROB
Authors: Du Shucen , Schlattmann Josef , Schulz Stefan , Seibel Arthur
Published: March 2016

The CENTAUROB is a mobile service robot which can operate in unstructured environments while always remain in a statically stable position. The special feature of this system is the use of two Stewart platforms as leg structures, providing high flexibility and maneuverability. By a special foot geometry (shape like a C), it has been possible for the first time to realize a walking biped which can even handle spiral staircases. In this paper, we present a new and advanced prototype of this system.
Visualisation of Diffuser Instabilities in a Wet Gas Compressor
Authors: Ferrara Veronica , Bakken Lars E.
Published: March 2016

The continuous demand for oil and gas pushes the petroleum industry to develop new technologies in order to increase production and exploit existing fields. The wet gas process, based on direct compression of unprocessed well stream subsea is a powerful means to expand the extraction of crude oil and gas and reach remote regions. Consequently centrifugal compressors are key elements that need to be developed in this area. Since no commercial subsea compressors are available and the liquid phase inside the standard process has to be avoided, it is essential to fully understand the machine behaviour, particularly investigate the presence of a gas-liquid mixture. Because of liquid impact, the performance of compressors and consequently the margin of stability may have to be modified. Here, delayed instability inception should be identified.

An ongoing research programme is conducted at the Norwegian University of Science and Technology (NTNU) concerning the influence of wet gas on performance and aerodynamic stability. An open loop wet gas test rig is designed and employed in an experimental campaign.

The main goal of this study is the visualisation of flow in a vaneless diffuser by means of special windows in Plexiglas, in correspondence with the diffuser and volute. Most attention is focused on the behaviour that leads to unstable phenomena, like stall and surge, in order to expose wet effects. Interactions between the diffuser and volute will also be taken into account. Simultaneously, the analysis will be supported by measurements from high-response dynamic pressure sensors. A fast Fourier transform (FFT) examination will be realised, in order to identify characteristic frequencies of unsteady events.
A Comparison of Angular Discretization Techniques for the Radiative Transport Equation
Authors: Tencer John
Published: March 2016

Two of the most popular deterministic radiation transport methods for treating the angular dependence of the radiative intensity for heat transfer: the discrete ordinates and simplified spherical harmonics approximations are compared. A problem with discontinuous boundary conditions is included to evaluate ray effects for discrete ordinates solutions. Mesh resolution studies are included to ensure adequate convergence and evaluate the effects of the contribution of false scattering. All solutions are generated using finite element spatial discretization. Where applicable, any stabilization used is included in the description of the approximation method or the statement of the governing equations. A previous paper by the author presented results for a set of 2D benchmark problems for the discrete ordinates method using the PN-TN quadrature of orders 4, 6, and 8 as well as the P1, M1, and SP3 approximations. This paper expands that work to include the Lathrop-Carlson level symmetric quadrature of order up to 20 as well as the Lebedev quadrature of order up to 76 and simplified spherical harmonics of odd orders from 1 to 15. Two 3D benchmark problems are considered here. The first is a canonical problem of a cube with a single hot wall. This case is used primarily to demonstrate the potentially unintuitive interaction between mesh resolution, quadrature order, and solution error. The second case is meant to be representative of a pool fire. The temperature and absorption coefficient distributions are defined analytically. In both cases, the relative error in the radiative flux or the radiative flux divergence within a volume is considered as the quantity of interest as these are the terms that enter into the energy equation. The spectral dependence of the optical properties and the intensity is neglected.