bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative assessment of preferential fatigue initiation sites in a multi‐phase aluminium alloy
Authors: JOYCE M. R. , LEE K. K. , SYNGELLAKIS S. , REED P. A. S. 
Published: August 2010

ABSTRACTComplex multi‐phase Al–Sn–Si alloys are commonly employed in the manufacture of small automotive plain bearings. The fundamental fatigue initiation behaviour of this class of alloys is currently not well understood. A range of analytical techniques were applied to investigate preferential initiation site location and to attempt to identify critical microstructural features. It was apparent from experimental studies that points of fatigue crack initiation are associated with the Si secondary phase. Using tessellation approaches and subsequently both adaptive numerical modelling and micro‐scale finite element modelling allowed the identification of features affecting the probability that a given Si phase would initiate a fatigue crack.
Material fatigue properties for assessing mechanical components weakened by notches and defects
Authors: ATZORI B. , MENEGHETTI G. , SUSMEL L. 
Published: August 2010

ABSTRACTThis paper addresses the problem of estimating the material fatigue properties for assessing real mechanical components. Initially, some practical rules are proposed to estimate the fully reversed plain fatigue limit, Δσ0, using the material tensile stress. These rules are obtained by subdividing materials into five different groups: carbon steels, low‐alloy steels, high‐alloy steels, aluminium alloys and cast irons. Subsequently, using a large database of fatigue data found in the literature, it is demonstrated that the fully reversed torsional plain fatigue limit can be directly estimated from the fully reversed uniaxial plain fatigue limit by simply using Von Mises' formula. Finally, some empirical equations are proposed to estimate El Haddad's short crack constant, a0. These equations are based on the assumption that this material property can be derived from the plain fatigue limit determined at a given load ratio, R. Since the a0 values depend on the load ratio, so a0 versus Δσ0 relationships can directly account for the R influence. The aim of this paper is to provide engineers engaged in assessing real structural components with empirical rules to estimate the material fatigue properties. All these pieces of information are needed to apply the most modern methods suitable for assessing components weakened by any kind of geometrical feature and subjected to any kind of fatigue loading.
Fracture behaviour of an Al2O3–ZrO2 multi‐layered ceramic with residual stresses due to phase transformations*
Authors: BERMEJO R. , TORRES Y. , SÁNCHEZ‐HERENCIA A. J. , BAUDÍN C. , ANGLADA M. , LLANES L. 
Published: August 2010

ABSTRACTThe fracture behaviour of a ceramic multi‐layer designed with thin internal compressive layers and obtained by slip casting is studied. It consists of nine alternated Al2O3–5vol%tZrO2 and Al2O3–30vol%mZrO2 layers of 530 μm and 100 μm thickness, respectively. Mechanical characterization includes evaluation of Vickers Hardness, Young's modulus and fracture strength under four‐point bending. In addition, the residual stress magnitude and distribution in the laminate is determined both analytically, from calculations using the differential strain between layers and the elastic properties, and experimentally, using indentation techniques. The experimental findings in terms of mechanical strength and fractography show a subcritical growth of the natural flaws in the laminate before catastrophic failure occurs, owing to the relevant role of the thin Al2O3–30vol%mZrO2 layers with compressive stresses inherent to the zirconia phase transformation. These layers are also responsible for the increase in toughness to levels of at least three times that of the reference Al2O3–5vol%tZrO2 monolith.
Fatigue life prediction of vulcanized natural rubber under proportional and non‐proportional loading
Authors: WANG Y. , YU W. , CHEN X. , YAN L. 
Published: August 2010

ABSTRACTTo investigate the multiaxial fatigue properties of vulcanized natural rubber (NR), a series of tests including both proportional and non‐proportional loading paths on small specimens were performed. The existing fatigue life prediction approaches are evaluated with life data obtained in the tests. It is shown that the equivalent strain approach presents a good prediction of the fatigue life although it has a certain shortcoming. Compared with the strain energy density (SED) model, the cracking energy density (CED) model represents the portion of SED that is available to be released by virtue of crack growth on a given material plane, so it gives better results in the life prediction. Some of the approaches based on critical plane which are widely used for metal fatigue are also tested in this paper, and the results show that the Chen‐Xu‐Huang (CXH) model gives a better prediction, compared with the Smith‐Watson‐Topper (SWT) and Wang–Brown (WB) model. A modified Fatemi–Socie's model has also been introduced, and the results show that the modified model can be used to predict the fatigue life of rubber material well.
Calculation of stress intensity factors for a longitudinal semi‐elliptical crack in a finite‐length thick‐walled cylinder
Authors: NABAVI S. M. , SHAHANI A. R. 
Published: August 2010

ABSTRACTThe purpose of this paper is to present the effect of finite boundary on the stress intensity factor of an internal semi‐elliptical crack in a pressurized finite‐length thick‐walled cylinder (Ri/t= 4). The three‐dimensional finite element method, in conjunction with the weight function method, is used for computing the stress intensity factor at the deepest and surface points of an axial semi‐elliptical crack in a cylinder. The transition aspect ratios, the aspect ratios in which the maximum stress intensity factor translates from the deepest to the surface points of the crack, are calculated for different relative depths and cylinder lengths. The results show that the stress intensity factor increases as the cylinder length decreases, especially at the corner point of the crack compared with the deepest point. The major advantage of this paper is that a closed‐form expression is extracted for the stress intensity factor at the surface point of a semi‐elliptical crack, which experiences higher changes due to the effect of the finite boundary of the cylinder.
Micromechanical interactions in a superduplex stainless steel subjected to low cycle fatigue loading
Authors: PENG R. LIN , CHAI G. , JIA N. , WANG Y. D. , JOHANSSON S. 
Published: August 2010

ABSTRACTMicromechanical interactions in an austenitic‐ferritic SAF 2507 steel under lowcycle fatigue loading was studied by experiment and simulation. Neutron diffraction measurements of residual lattice strains were made on specimens unloaded from different cyclic deformation stages, namely cyclic hardening, softening and saturation. With self‐consistent modelling, the micromechanical behaviour of the constituent phases was studied for the first loading cycle. The evolution of the residual lattice strain distributions with cyclic loading and the development of phase stresses have been analysed with respect to the initial residual stress field and the different mechanical properties of the constituent phases.
Serum or target deprivation‐induced neuronal death causes oxidative neuronal accumulation of Zn2+ and loss of NAD+
Authors: Sheline Christian T. , Cai Ai‐Li , Zhu Julia , Shi Chunxiao 
Published: August 2010

AbstractTrophic deprivation‐mediated neuronal death is important during development, after acute brain or nerve trauma, and in neurodegeneration. Serum deprivation (SD) approximates trophic deprivation in vitro, and an in vivo model is provided by neuronal death in the mouse dorsal lateral geniculate nucleus (LGNd) after ablation of the visual cortex (VCA). Oxidant‐induced intracellular Zn2+ release ([Zn2+]i) from metallothionein‐3 (MT‐III), mitochondria or ‘protein Zn2+’, was implicated in trophic deprivation neurotoxicity. We have previously shown that neurotoxicity of extracellular Zn2+ required entry, increased [Zn2+]i, and reduction of NAD+ and ATP levels causing inhibition of glycolysis and cellular metabolism. Exogenous NAD+ and sirtuin inhibition attenuated Zn2+ neurotoxicity. Here we show that: (1) Zn2+ is released intracellularly after oxidant and SD injuries, and that sensitivity to these injuries is proportional to neuronal Zn2+ content; (2) NAD+ loss is involved – restoration of NAD+ using exogenous NAD+, pyruvate or nicotinamide attenuated these injuries, and potentiation of NAD+ loss potentiated injury; (3) neurons from genetically modified mouse strains which reduce intracellular Zn2+ content (MT‐III knockout), reduce NAD+ catabolism (PARP‐1 knockout) or increase expression of an NAD+ synthetic enzyme (Wlds) each had attenuated SD and oxidant neurotoxicities; (4) sirtuin inhibitors attenuated and sirtuin activators potentiated these neurotoxicities; (5) visual cortex ablation (VCA) induces Zn2+ staining and death only in ipsilateral LGNd neurons, and a 1 mg/kg Zn2+ diet attenuated injury; and finally (6) NAD+ synthesis and levels are involved given that LGNd neuronal death after VCA was dramatically reduced in Wlds animals, and by intraperitoneal pyruvate or nicotinamide. Zn2+ toxicity is involved in serum and trophic deprivation‐induced neuronal death.
Post dural puncture headache in a pediatric patient with idiopathic intracranial hypertension
Authors: NAFIU OLUBUKOLA O. , MONTEROSSO DOMINIC , WALTON SARAH R. , BRADIN STUART 
Published: August 2010

SummaryWe describe the occurrence of postdural puncture headache (PPDH) in an adolescent with idiopathic intracranial hypertension (IIH) and its successful management with an epidural blood patch. PPDH is a very rare occurrence in patients with intracranial hypertension and is described as a paradoxical situation in the literature. There are only two previous case reports (in adults) of the possible association. A 15‐year‐old obese patient with a diagnosis of IIH had an uneventful diagnostic spinal tap using a 22G Quincke needle in the pediatric emergency department but returned 24 h later with PPDH. After a failed trial of conservative management, she had an uneventful but curative epidural blood patch with 15 ml of autologous venous blood and was able to return to school the day after the blood patch. Follow‐up review by her neuro‐ophthalmologist shows resolution of her headaches, considerable improvement in her visual field defect and resolution of papilledema. This is the first report of PPDH and its successful management with an epidural blood patch in a pediatric patient with IIH.
Creation of a head and face protection device for children undergoing procedures in prone position
Authors: WENK MANUEL , PÖPPING DANIEL , HENNING MARTIN , WENK MELANIE , LILJENQVIST ULF , MÖLLMANN MICHAEL 
Published: August 2010

SummaryBackground:  Positioning the head of patients undergoing procedures in lateral or prone position remains a difficult task for the anesthesiologists. Associated risks have attracted increasing attention because they range from minor facial soft tissue injuries to catastrophic complications such as stroke or postoperative blindness. Earlier, we reported on the use of a boxing sports helmet for simple and easy positioning of the head. However, as available helmets are limited in sizes and materials, that system is not easily transferable to children. Therefore, we sought to create a face and head protection device for children undergoing procedures in prone position.Methods/Materials:  We re‐engineered a standard boxing sports helmet making it suitable as an on‐head support cushion. By using WHO standard growth charts, various sizes were calculated and prototypes of different foam materials produced. Facial surface pressures were measured in 15 volunteers.Results:  A lightweight foam‐based face mask was created. Minimum necessary foam thickness was 2.5 cm. Different materials were tested and pressure in different facial zones never exceeded 30 mmHg.Conclusion:  Bringing a face protection device onto the patient’s face instead of placing the face into support cushions is an elegant way of keeping control over airway devices and providing support for facial structures in various positions simultaneously. Skin surface pressure on facial structures remained low due to the specific mask design and choice of foam materials, which could lead to decreased incidences of undesired sequelae of prone position such as skin damage or even more devastating complications.
Pediatric airway management: comparing the Berci–Kaplan Video Laryngoscope with direct laryngoscopy
Authors: MACNAIR DAVID , BARACLOUGH DAN , WILSON GRAHAM , BLOCH MARK , ENGELHARDT THOMAS 
Published: August 2010

SummaryObjectives:  To assess the utility of the Berci–Kaplan Video Laryngoscope (VL) in pediatric anesthesia.Background:  The VL is designed to improve visualization of the glottis during tracheal intubation of normal and difficult airways in adults. This study was designed to assess the visual quality and the ease of tracheal intubation in children using the VL when compared with direct laryngoscopy (DL).Methods:  Sixty children, aged 2–16 years requiring tracheal intubation, were enrolled in this prospective, randomized clinical trial. Following induction of anesthesia and muscle paralysis, the first laryngoscopy method, using either a DL or the VL, was performed by one anesthetist, and the laryngoscopic view was graded according to the Cormack–Lehane scale. Laryngoscopy and grading of the view in the second method were then performed by a second anesthetist. Tracheal intubation was completed following the second laryngoscopy, and time to intubation was recorded.Results:  The average age and weight were 8.9 ± 3.6 years and 34.9 ± 16.0 kg respectively. Videolaryngoscopy improved 8/11 grade 2 views to grade 1 (P = 0.02), and one grade 3 to a grade 2. Three grade 2 views remained unchanged from DL to VL. 4/30 VL intubations required two attempts, and 1/30 failed after two attempts, but was easily intubated with DL. Median time (range) was 16.0 s (14.0–20.0 s) and 22.5 s (17.8–35.0 s) for DL and VL respectively (P < 0.001).Conclusion:  Videolaryngoscopy provides better views than DL at the expense of time to intubate. Although the time taken to intubate is increased with the VL, it is clinically acceptable.
Review article: Perioperative care of patients with epidermolysis bullosa: proceedings of the 5th international symposium on epidermolysis bullosa, Santiago Chile, December 4–6, 2008
Authors: GOLDSCHNEIDER KENNETH , LUCKY ANNE W. , MELLERIO JEMIMA E. , PALISSON FRANCIS , Del CARMEN VIÑUELA MIRANDA MARIA , AZIZKHAN RICHARD G. 
Published: August 2010

SummaryEpidermolysis bullosa (EB) has become recognized as a multisystem disorder that poses a number of pre‐, intra‐, and postoperative challenges. While anesthesiologists have long appreciated the potential difficult intubation in patients with EB, other systems can be affected by this disorder. Hematologic, cardiac, skeletal, gastrointestinal, nutritional, and metabolic deficiencies are foci of preoperative medical care, in addition to the airway concerns. Therefore, multidisciplinary planning for operative care is imperative. A multinational, interdisciplinary panel of experts assembled in Santiagio, Chile to review the best practices for perioperative care of patients with EB. This paper presents guidelines that represent a synthesis of evidence‐based approaches and the expert consensus of this panel and are intended to aid physicians new to caring for patients with EB when operative management is indicated. With proper medical optimization and attention to detail in the operating room, patients with EB can have an uneventful perioperative course.
Testing the Janzen‐Connell mechanism: pathogens cause overcompensating density dependence in a tropical tree
Authors: Bagchi Robert , Swinfield Tom , Gallery Rachel E. , Lewis Owen T. , Gripenberg Sofia , Narayan Lakshmi , Freckleton Robert P. 
Published: August 2010

Ecology Letters (2010)AbstractThe Janzen‐Connell hypothesis is a leading explanation for plant‐species diversity in tropical forests. It suggests that specialized natural enemies decrease offspring survival at high densities beneath parents, giving locally rarer species an advantage. This mechanism, in its original form, assumes that density dependence is overcompensating: mortality must be disproportionately high at the highest densities, with few offspring recruiting below their parents. We tested this assumption using parallel shadehouse and field density‐series experiments on seedlings of a tropical tree, Pleradenophora longicuspis. We found strong, overcompensating mortality driven by fungal pathogens, causing 90% (shadehouse) or 100% (field) mortality within 4 weeks of germination, and generating a negative relationship between initial and final seedling densities. Fungicide treatment led to much lower, density‐independent, mortality. Overcompensating mortality was extremely rapid, and could be missed without detailed monitoring. Such dynamics may prevent dead trees from being replaced by conspecifics, promoting coexistence as envisioned by the Janzen‐Connell hypothesis.
Do sexual pheromone traps provide biased information of the local gene pool in the pine processionary moth?
Authors: Salvato P. , Simonato M. , Zane L. , Patarnello T. , Masutti L. , Battisti A. 
Published: August 2010

Abstract  1 Sexual pheromone traps are commonly used to monitor populations of the pine processionary moth, Thaumetopoea pityocampa, assuming that trapped males are representative of the breeding population.2 For seven Italian populations, mitochondrial haplotypes (COI and COII) of adult males caught in traps were compared with those of larvae obtained from egg batches laid in the same year, to test whether the males trapped were representative of the local populations.3 The distribution of haplotype frequencies revealed substantial homogeneity between adult males and larvae samples from the same population, except for Aosta Ruines Verrès, a population recently expanding in the south‐western Alps. In this case, the results suggested that trapped males were recruited over a wider area than local moths because haplotype diversity was higher than that of larvae.4 A further analysis of this population using nuclear markers (AFLP) confirmed that adults, collected in pheromone traps, were genetically different from the larvae emerging in the same stand.5 In conclusion, the assumption that trapped males are representative of breeding populations was confirmed for core populations, but has not been verified for the recently established population of Aosta Ruines Verrès. This should encourage discussion with respect to the reliability of pheromone traps in monitoring programmes of the pest, especially at the range's edge.
Soil type and microtopography influencing feeding above and below ground by the pine weevil Hylobius abietis
Authors: Nordlander Göran , Bylund Helena , Björklund Niklas 
Published: August 2010

Abstract  1 The influence of soil type and microtopography on above and below ground feeding by adult pine weevils Hylobius abietis (L.) (Coleoptera: Curculionidae) was evaluated in a field experiment with enclosed weevil populations of known size.2 Four soil treatments, each with a food source at the centre, were presented within each enclosure: (i) a flat surface with fine‐grained, cultivated humus; (ii) a flat surface with sand; (iii) a conical mound of sand; and (iv) a conical pit in sand. The food source consisted of a stem section of Scots pine Pinus sylvestris L. extending both above and below ground.3 The majority of feeding on the half buried stem sections occurred below ground; only 2.7% of the total bark area consumed was situated above ground. The variation over time in bark area consumed was not significantly associated with any of the tested weather factors.4 The amount of feeding was 10‐fold higher on food sources placed in fine‐grained humus than those in areas of flat sand.5 Less pine bark was consumed on mounds of sand than flat sand surfaces, and there was more feeding in sandy pits than on flat sand. These effects on feeding are explained by the observation that the weevils had difficulties climbing the sandy slopes (27° gradient).6 We conclude that pine weevil damage to conifer seedlings can be considerably reduced by planting on mounds of pure mineral soil and that planting deeply in the soil increases the risk of damage.
Occurrence of Ips typographus (Col., Scolytidae) along an urbanization gradient in Brussels, Belgium
Authors: Piel Frédéric , Gilbert Marius , Franklin Anne , Grégoire Jean‐Claude 
Published: August 2010

Abstract  1 The distribution and dynamics of insect populations in cities is poorly understood. One approach to address this question is to explore the permeability of the urban habitat to species from surrounding rural areas, which can serve as reservoirs in source‐sink dynamics.2 Here, we present data on the distribution of the forest insect pest of spruce, Ips typographus (Coleoptera, Scolytidae), along two axes entering the city of Brussels (Belgium) from the south‐east and to the town centre.3 The insect was caught everywhere along these transects, even in heavily urbanized surroundings, and sometimes in relatively high numbers. The catches were highest near the middle of the transects and lower at both ends of them.4 This pattern was associated, on the one hand, with an urbanization gradient with the numbers of flying individuals increasing with the distance from the city centre and, on the other hand, with lower catches at the periphery of the city where a high proportion of broadleaved trees may have disrupted the response to aggregation pheromones.5 In addition to the probable rural origin of the beetles, high catches at the Port of Brussels indicated that some of the insects might be of foreign origin and enter the city with imported timber, highlighting a pathway for unintentional introductions of organisms, including potentially invasive species.
Factors influencing adult female oviposition in the citrus leafminer Phyllocnistis citrella
Authors: Vercher R. , Farias A. , Marzal C. , Soto A. , Tena A. , Garcia‐Marí F. 
Published: August 2010

Abstract1 The citrus leafminer (CLM) Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is a serious pest in most citrus‐growing regions of the world. The influence of leaf length, citrus species or variety, leaf colour tone and temperature on CLM oviposition was studied from field observations and laboratory experiments. The spatial distribution of eggs on leaves was also examined. Field data were obtained from 1100 samples collected in eastern Spain for 7 years.2 Significant differences in oviposition rate were found among citrus species in ‘no choice’ laboratory experiments. This tendency was not apparent in the field due to the confounding effect of such factors as the intensity of new flushes and adult CLM abundance. Leaf colour tone and air temperature in the range studied (18–27°C) had no effect on CLM egg‐laying.3 The distribution of eggs among leaves was random for population densities lower than four eggs per leaf, but became strongly aggregated above this, when not all eggs could survive and complete development.4 The CLM developmental stage found on leaves depended on the leaf length, and most of the egg‐laying occurred only on leaves that were 10–25 mm long. These leaves had the highest CLM stages in the field and thus give the best estimate of CLM oviposition.