Minor Surface Research Articles

First-Year Composition as “Big Data”: Towards Examining Student Revisions at Scale

Abstract Given the central role revision plays in our First-Year Composition (FYC) program and the enormous number of papers students produce each semester across all course sections, we approached student revision as a “big data” phenomenon, assembling a large corpus of student papers and developing software to process them. Unlike past studies of revision which found that students focus almost exclusively on minor edits and surface errors, we found that student revisions primarily involve deleting and, more frequently, inserting complete sentences. After describing our software and reviewing its results, we examine several situational variables that may influence this unanticipated practice, and discuss ways to integrate revision more fully into the writing classroom.

Consensus on procedures to include in a simulation-based curriculum in ophthalmology: a national Delphi study.

The number of available simulation-based models for technical skills training in ophthalmology is rapidly increasing, and development of training programmes around these procedures should follow a structured approach. The aim of this study was to identify all technical procedures that should be integrated in a simulation-based curriculum in ophthalmology. Key opinion leaders involved in the education of ophthalmologists in Denmark including heads of departments, heads of clinical education, professors and board members of the society were invited to participate in a three-round Delphi process. Round 1 aimed at identifying technical procedures that physicians should be able to perform competently when completing specialty training; round 2 involved characterization of each procedure including frequency, number of operators, risk and/or discomfort for patients associated with an inexperienced physician, and feasibility of simulation-based training; round 3 included a priority ranking of procedures. The response rate for each round was 71%, 64% and 64%, respectively. Sixty-five procedures were reduced to 25 prioritized procedures during the three rounds. Two-thirds of the procedures that were identified and highly prioritized were therapeutic procedures such as intravitreal injection therapy, yttrium-aluminium-garnet laser iridotomy/capsulotomy, minor ocular surface procedures and retinal argon laser therapy. The diagnostic procedures that were prioritized were ocular ultrasound, superficial keratectomy and optical coherence tomography (OCT). The Delphi process identified and prioritized 25 procedures that should be practised in a simulation-based environment to achieve competency before working with patients. The list may be used to guide the development of future training programmes for ophthalmologists.

Morphometric properties of the levator scapulae, rhomboid major, and rhomboid minor in human fetuses

The main objective of this study is to showcase the growth dynamics of levator scapulae, rhomboid major, and rhomboid minor algebraically, to help plan surgeries on newborns and young infants. Twenty-five formalin-fixed fetuses (11 male-14 female) with a mean gestational age of 21.80 ± 2.61 (range 18-27) weeks present in the inventory of Mersin University Faculty of Medicine Anatomy Department were dissected. Surface area of levator scapulae, rhomboid major, and rhomboid minor was calculated using digital image analysis software; width and length parameters were measured using digital calipers. Neither sex nor side significant differences were observed in relation with the numerical data of levator scapulae, rhomboid major, and rhomboid minor (p > 0.05). Algebraic parameters such as surface area, width and length were detected to exhibit a linear growth from 18th to 27th week. Linear functions for levator scapulae, rhomboid major and rhomboid minor surface areas were obtained as y = - 136.871 + 10.598 × age (weeks), y = - 480.567 + 33.147 × age (weeks) and y = - 128.090 + 8.843 × age (weeks), respectively. The results and data of this study can potentially be beneficial in planning of surgeries for many infancy diseases such as trapezius paralysis, obstetrical brachial plexus palsy, Sprengel's disease, or winged scapula. Linear functions calculated in this study are expected to provide a better understanding of the growth dynamics of levator scapulae, rhomboid major, and rhomboid minor in fetal term and more precise estimation of muscle sizes.

Direct transformation of waste printed circuit boards to nano-structured powders through mechanical alloying

Identifying a solution to directly transform waste printed circuit boards (PCBs) to useful alloys will save energy, conserve our valuable resources, and contribute to preservation of our environment. In this study a solid state mechanical alloying was used to directly convert waste PCBs to a homogenous nanostructured alloy (Cu79-Zn13-Fe3-Sn3-Ni1). Electron microscopy analysis showed 10h milling time after a short period of cryomilling was enough to obtain a homogenous alloy and SAED ring pattern confirmed the nano-structure, although just a portion of particles size of the power was in nano-scale (<100nm). Lattice parameter, strain and grain size were calculated using XRD analysis. The grain size was 40nm with a strain of 0.73%. High resolution XPS analysis confirmed minor surface oxidation of produced alloy. The UV–Vis analysis showed a broad peak between 350 and 650nm indicating the chemical homogeneity of the surface. Also the calculation of input energy confirmed the formation of a nano-structured material during mechanical alloying. Finally, a promising application was investigated as nanofluid after dispersion of the synthesised powder in DI water followed by characterization of pH and conductivity variation. The conductivity of the sample was about 10 times higher than DI water. These results, for the first time, introduce a concept for directly transform waste PCBs to metallic alloys without using any heat or solutions.

Sorption of Sr, Co and Zn on illite: Batch experiments and modelling including Co in-diffusion measurements on compacted samples

Experimental investigations on the uptake of divalent cations (Sr, Co and Zn) onto illite (Illite du Puy, Le-Puy-en-Velay, France) were carried out by three different international research groups (Institute for Nuclear Waste Disposal, KIT (Germany), Group Waste & Disposal, SCK-CEN, (Belgium) and Laboratory for Waste Management, PSI (Switzerland)) in the framework of the European FP7 CatClay project. The dependence of solid-liquid distribution ratios (Rd values) on pH at trace metal conditions (sorption edges) and on the metal ion concentration (sorption isotherms) was determined in dilute suspensions of homo-ionic Na-illite (Na-IdP) under controlled N2 atmosphere. The experimental results were modelled using the 2 Site Protolysis Non Electrostatic Surface Complexation and Cation Exchange (2SPNE SC/CE) sorption model. The sorption of Sr depends strongly on ionic strength, while a rather weak pH dependence is observed in a pH range between 3 and 11. The data were modelled with cation exchange reactions, taking into account competition with H, K, Ca, Mg and Al, and surface complexation on weak amphotheric edge sites at higher pH values. The sorption of Co on Na-IdP, however, is strongly pH dependent. Cation exchange on the planar sites and surface complexation on strong and weak amphoteric edge sites were used to describe the Co sorption data. Rd values for Co derived from in-diffusion measurements on compacted Na-IdP samples (bulk-dry density of 1700 kg m−3) between pH 5.0 and 9.0 are in good agreement with the batch sorption data. The equivalence of both approaches to measure sorption was thus confirmed for the present test system. In addition, the results highlight the importance of both major and minor surface species for the diffusive transport behaviour of strongly sorbing metal cations. While surface complexes at the edge sites determine largely the Rd value, the diffusive flux may be governed by those species bound to the planar sites, even at low fractional occupancies. The pH dependent sorption determined for trace Zn concentrations showed large Rd values across the entire pH range with almost no dependence on the background electrolyte concentration. Additional sorption experiments carried out at substantial fractional Zn loadings demonstrated that the selectivity for the exchange of Na+ for Zn2+ at the planar sites could not explain the large Rd values measured at low pH and trace Zn concentrations. This suggests that another mechanism is ruling Zn uptake under these conditions.

Erosive Tooth Wear: Knowledge Of Diagnosis And Treatment Strategies Among Private Dental Practitioners In Kuantan, Pahang

Introduction: Awareness of erosive tooth wear (ETW) by the public is still low and most dental practitioners overlooked the very early stages dismissing minor tooth surface loss of erosive tooth wear. Therefore, this study aimed to assess knowledge of diagnosis and treatment strategies of ETW among private dental practitioners (PDP) in Kuantan. Materials and Methods: A crosssectional study was conducted in Kuantan private clinics involving PDP and general dental practitioners who performed locum by using convenience sampling. A self-administered validated questionnaire was distributed and descriptive analysis was performed. Results: Overall response rate was 75%. Results indicated that majority of participants (79.2%) received formal education about ETW. About half of participants further learned through continuous dental education. All participants agreed that carbonated drink was the cause of ETW and majority of them reported that gastro-esophageal reflux diseases and pickles also contributed to ETW. Regarding ETW documentation, majority of participants (79%) preferred case notes. Nevertheless, 40.9% and 36.4% record at tooth surface level and individual level respectively. In term of specific scoring in assessing ETW, 79% of them did not know about it. Most of participants prefer giving oral hygiene instruction and diet counseling as preventive measures; however usage of fluorides was not prioritized. 77% of participants never referred case to dental specialist and prefer to treat patient by themselves. Conclusion(s): Knowledge of ETW among recruited PDP is adequate however they did not use any specific indices for ETW scoring and treatment strategies were insufficient.

RAZA: A Rapid 3D z-crossings algorithm to segment electron tomograms and extract organelles and macromolecules.

Resolving the 3D architecture of cells to atomic resolution is one of the most ambitious challenges of cellular and structural biology. Central to this process is the ability to automate tomogram segmentation to identify sub-cellular components, facilitate molecular docking and annotate detected objects with associated metadata. Here we demonstrate that RAZA (Rapid 3D z-crossings algorithm) provides a robust, accurate, intuitive, fast, and generally applicable segmentation algorithm capable of detecting organelles, membranes, macromolecular assemblies and extrinsic membrane protein domains. RAZA defines each continuous contour within a tomogram as a discrete object and extracts a set of 3D structural fingerprints (major, middle and minor axes, surface area and volume), enabling selective, semi-automated segmentation and object extraction. RAZA takes advantage of the fact that the underlying algorithm is a true 3D edge detector, allowing the axes of a detected object to be defined, independent of its random orientation within a cellular tomogram. The selectivity of object segmentation and extraction can be controlled by specifying a user-defined detection tolerance threshold for each fingerprint parameter, within which segmented objects must fall and/or by altering the number of search parameters, to define morphologically similar structures. We demonstrate the capability of RAZA to selectively extract subgroups of organelles (mitochondria) and macromolecular assemblies (ribosomes) from cellular tomograms. Furthermore, the ability of RAZA to define objects and their contours, provides a basis for molecular docking and rapid tomogram annotation.

Comparison of Alterations in the Surface Topographies of HyFlex CM and HyFlex EDM Nickel-titanium Files after Root Canal Preparation: A Three-dimensional Optical Profilometry Study

AimsThe aims of the present study were to examine the surface topographies of intact HyFlex CM and HyFlex EDM nickel-titanium files and to compare alterations in the surface topographies of these files after root canal preparation of severely curved canals of molar teeth. MethodsEight HyFlex CM (25/.08) and 8 HyFlex EDM (25/.08) files were included in the present study. In total, 64 severely curved canals of molar teeth, with curvature angles ranging between 50° and 70°, were prepared with HyFlex CM and EDM (n = 32 in each group). Quantitative and qualitative analyses of the files' surface deformation were performed by using three-dimensional optical profilometry before and after root canal preparation. The data were analyzed with the Student t test at the 5% significant level by using SPSS 21.0 software. ResultsIn the HyFlex EDM group, the qualitative evaluation revealed the presence of cracks and microcavities after use of the file for root canal preparation, whereas only minor surface deformation was observed in the HyFlex CM group. The average roughness, root mean square roughness, and peak to valley height values of the HyFlex EDM group were significantly higher than those of the HyFlex CM group before and after root canal preparation (P < .05). The surface roughness values were statistically significantly increased in the HyFlex CM group after root canal preparation (P < .05). In contrast, the increase in the HyFlex EDM group was not statistically significant (P > .5). ConclusionsWithin the limitations of the present study, the HyFlex CM files showed significantly higher surface alterations compared with the HyFlex EDM files after the preparation of severely curved root canals.

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

Abstract Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag+ ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model‐data comparison

AbstractWe investigate the impact of different CO2 levels and different subarctic gateway configurations on the surface temperatures during the latest Cretaceous using the Earth System Model COSMOS. The simulated temperatures are compared with the surface temperature reconstructions based on a recent compilation of the latest Cretaceous proxies. In our numerical experiments, the CO2 level ranges from 1 to 6 times the preindustrial (PI) CO2 level of 280 ppm. On a global scale, the most reasonable match between modeling and proxy data is obtained for the experiments with 3 to 5 × PI CO2 concentrations. However, the simulated low‐ (high‐) latitude temperatures are too high (low) as compared to the proxy data. The moderate CO2 levels scenarios might be more realistic, if we take into account proxy data and the dead zone effect criterion. Furthermore, we test if the model‐data discrepancies can be caused by too simplistic proxy‐data interpretations. This is distinctly seen at high latitudes, where most proxies are biased toward summer temperatures. Additional sensitivity experiments with different ocean gateway configurations and constant CO2 level indicate only minor surface temperatures changes (&lt;~1°C) on a global scale, with higher values (up to ~8°C) on a regional scale. These findings imply that modeled and reconstructed temperature gradients are to a large degree only qualitatively comparable, providing challenges for the interpretation of proxy data and/or model sensitivity. With respect to the latter, our results suggest that an assessment of greenhouse worlds is best constrained by temperatures in the midlatitudes.

Mechanical Preparation Showed Superior Shaping Ability than Manual Technique in Primary Molars - A Micro-Computed Tomography Study.

Manual instrumentation is still reported as the main choice in the primary teeth preparation; however, studies have shown limitations in its use. The morphological characteristics of primary teeth and the limited knowledge of shaping procedures in these teeth using mechanical preparation become a challenge for clinical practice and might impair the predictability of endodontic treatment.

Leaf cuticle-assisted phototransformation of isoproturon

Isoproturon is a pre- and post-emergence herbicide used generally to manage Phalaris minor and Avena ludoviciana in wheat. The importance of post-emergence and foliarly applied pesticides has been increasing. The first reaction environment of these herbicides is the leaf surface made up of polymerised esters of higher fatty acids. In the presence of sunlight, the fatty substances on leaf surfaces generate reactive radicals, or ions which may interact with herbicide molecules leading towards degradation resulting in the loss of bioefficacy of herbicides and the formation of metabolites of unknown toxicity. The present experiment was conducted with the objective to know the photochemical behaviour of isoproturon on different leaf-extracted epicuticular cutin surfaces. Epicuticular waxes, i.e. cutins were extracted from P. minor and A. ludoviciana leaf surfaces using dichloromethane as a solvent and further purified with activated charcoal. On the cutin surface under UV-light (365 nm), the transformation of the herbicide is very slow as it is evident from its higher half-life values, 75 min on P. minor cutin surface and 115 min on A. ludoviciana cutin, as compared to that on the glass surface (half-life 53 min). A similar pattern was also observed under the sunlight condition. It may be due to the quenching effect imparted by the cutin material or simply screening effect of it on the herbicide. The sunlight-irradiated extracts of isoproturon and its degradation products were analysed by LC–MS/MS using electrospray interfacing technique and the structures of six different photoproducts were characterised by their respective spectra. The degradation pathways involved mainly demethylation and ring oxidation processes forming hydroxylated compounds. The mixture of these photoproducts were found to be non-toxic to A. ludoviciana and P. minor.

Chemical composition and morphology study of bovine enamel submitted to different sterilization methods.

The morphology and chemical composition of enamel submitted to different sterilization methods was studied. X-ray photoelectron spectroscopy (XPS), field emission gun scanning electron microscopy (FEG-SEM), and energy-dispersive X-ray spectroscopy (EDS) were performed to evaluate 50 bovine enamel specimens sterilized using four methods: microwaving (MI), gamma irradiation (GI), ethylene oxide (EO), and steam autoclave (SA). Non-sterilized specimens were used as control. XPS indicated that the concentration of P (phosphorus), CO3 (carbonate), and CO3/P was not changed in all groups. GI produced no significant change on elemental composition. SA produced the major decrease in calcium (Ca), Ca/P ratio, and increase in N (nitrogen). MI was found to decrease Ca, Ca/P ratio and O (oxygen), and increase in C (carbon) and N. EO produced decrease in Ca and O with increased C concentration. FEG-SEM revealed surface and in-depth morphological changes on SA specimens. Minor surface alterations were observed for EO and for MI groups, and no alteration was observed on GI group. EDS indicated no difference on elemental composition of enamel bulk among groups. SA produced mineral loss and morphological alterations on surface and in depth. MI and EO sterilization caused mineral loss showing only slight alteration on enamel surface. GI sterilization preserves the morphological characteristics of enamel. The sterilization methods could be classified from lower to high damage as GI<MI<EO<SA. This is a comprehensive comparative study where different methods for enamel sterilization were investigated in terms of chemical changes. The results presented here may help researchers to choose the most appropriate method for their research setting and purpose.

Rapid fabrication of electrohydrodynamic micro-/nanostructures with high aspect ratio using a leaky dielectric photoresist

A leaky dielectric photoresist was designed and prepared for rapid fabrication of high-aspect-ratio micro-/nanostructures via electrohydrodynamic patterning (EHDP). The rheological behavior and electrical properties of the photoresists were systematically investigated, since the structure formation in EHDP essentially originates from the flow and deformation of the polymeric film actuated by an applied electric field. It is found that the photoresists exhibit the suitable rheological behavior with a low viscosity of 2.4–157.7mPas, controllable electrical conductivity of 5.0×10−6−7.2×10−4Sm−1, as well as high homogeneity, minor surface tension of about 30 mN·m−1, favorable wettability and film-forming property on substrate and an extremely large reduction in the contact angle (down to 1.64°) of electrowetting on dielectric (EWOD). The EHDP results have shown that a higher electrical conductivity of the photoresists can lead to a higher filling height, a smaller characteristic wavelength and a shorter patterning time, while a lower viscosity can also lead to a shorter patterning time, which is accordance with the theoretical prediction. In addition, the patterning time of the photoresists cannot be too short because the following rapid ripening and coalescence of the formed microstructure will damage the high fidelity of the final pillar arrays.

Investigation of the size of the incandescent incipient soot particles in premixed sooting and nucleation flames of n-butane using LII, HIM, and 1 nm-SMPS

ABSTRACTLaser-induced incandescence (LII) measurements were conducted to explore the ability of LII to detect small soot particles of less than 10 nm in two sooting flat premixed flames of n-butane: a so-called nucleation flame obtained at a threshold equivalence ratio Φ = 1.75, in which the incipient soot particles undergo only minor soot surface growth along the flame, and a more sooting flame at Φ = 1.95. Size measurements were obtained by modeling the time-resolved LII signals detected using 1064 nm laser excitation. Spectrally-resolved LII signals collected in the nucleation flame display a similar blackbody-like behavior as mature soot. Soot particle temperature was determined from spectrally-resolved detection. LII modeling was conducted using parameters either relevant to those of mature soot or derived from fitting the modeled results to the experimental LII data. Particle size measurements were also carried out using (1) ex situ analysis by helium-ion microscopy (HIM) of particles sampled thermo...

Evaluation of corneal topographic changes and surgically induced astigmatism after transconjunctival 27-gauge microincision vitrectomy surgery.

To evaluate the corneal topographic changes and postvitrectomy astigmatism after 27-gauge (g) microincision vitrectomy surgery (MIVS) by using Pentacam HR-Scheimpflug imaging system. This prospective descriptive study included 30 eyes of 30 patients who underwent 27-g MIVS. All eyes underwent a Pentacam HR examination preoperatively and on the first week, first month and third month postoperatively. The power of the corneal astigmatism, mean keratometry (K m), K 1 and K 2 values and corneal asphericity (Q value) values for the both front and back surfaces of the cornea, index of surface variance (ISV), index of vertical asymmetry (IVA), index of height asymmetry (IHA), index of height decentration (IHD) and higher-order aberrations including coma, trefoil, spherical aberration, higher-order root-mean-square and total RMS were recorded. Additionally, the mean induced astigmatism was estimated by vector analysis. No statistically significant changes were observed in the mean power of corneal astigmatism, mean keratometry, K 1 and K 2 values, corneal asphericity values, ISV, IVA, IHA, IHD and higher-order aberrations on the first week, first month and third month after the operation. The mean surgically induced astigmatism was calculated as 0.23±0.11 D on the first week, 0.19±0.10 D on the first month and 0.19±0.08 D on the third month postoperatively. Minor corneal surface and induced astigmatic changes are expected to result in rapid visual rehabilitation after pars plana vitrectomy with the 27-g MIVS system.

Dynamics of surface runoff and soil loss from a toposequence under varied land use practices in Rwizi catchment, Lake Victoria Basin

In this study, we quantified surface runoff and soil loss along a toposequence considering four land use systems and three topographic segment positions in Rwizi catchment, Lake Victoria Basin (LVB). The land use systems were grassland dominated by a local species known as “Omugugu” (<i>Cyperus</i> spp.), tree plantation of pine (<i>Pinus sabiniana</i>) and eucalyptus (<i>Eucalyptus globus</i>), mulched banana (<i>Musa Paradisiaca</i>), and unmulched banana, topographically located on the foot slope, midslope, and summit. Runoff and soil loss magnitude and trends under varied rainfall regimes were measured using closed runoff plots measuring 2 × 20 m (40 m²). A split plot experimental design was adopted for the study. In total, 36 runoff plots were installed considering the land use and topographic factors with three replications. Observed monthly rainfall values varied from 9.3 to 167 mm (75 ± 54 mm). Annually, the registered rainfall depth was 680 mm. The annual rainfall depth was below the long-term annual mean for the area. Nearly all rainfall events with a depth greater than 10 mm contributed relatively heavy runoff, while rainfall events less than 10 mm in general caused minor surface runoff at the sites. Annual runoff within the catchment at the studied sites varied from 42 to 411 m³ ha⁻¹ y⁻¹. The average observed cross-site annual runoff was 151 ± 95 m³ ha⁻¹ y⁻¹. Results show that annual runoff was in the order of tree plantation &gt; unmulched banana sites &gt; grassland = mulched banana. Soil losses were greatest (1.5 t ha⁻¹ y⁻¹) and lowest (0.8 t ha⁻¹ y⁻¹) on unmulched banana and mulched banana sites, respectively. Annual soil loss showed an increase with topographic slope segment position. Average annual soil loss on the upper slope position facets (1.7 t ha⁻¹ y⁻¹) were 2.4 folds higher than those observed on the footslope position facets (0.7 t ha⁻¹ y⁻¹), giving a percentage difference of 83%. We did not detect a statistical difference in runoff (<i>p</i> &gt; 0.05) due to either land use system or toposequence position. However, statistical differences were observed in soil loss (<i>p</i> &lt; 0.05) for land use system and toposequence position. While the observed annual soil loss magnitude is within the tolerable thresholds, a sustained maintenance of best land use practices is still critical in maintaining the delicate balance on the fragile hillslopes in the study area.

Reactivity of Two-Dimensional Au9, Pt9, and Au18Pt18 against Common Molecules.

Adsorption of common molecules over two-dimensional Au9, Pt9, and Au18Pt18 is investigated with implementation of first-principles calculations. In general, it is found that Pt9 and Au18Pt18 exhibit low adsorption energies where Au18Pt18 preserves the structural integrity of the molecule and surface. In particular, adsorption of molecules onto Au18Pt18 frequently results in low adsorption energies and high reactivity with minor surface reconstruction of Au18Pt18 and average bond lengths of molecules. The decrease in adsorption energy can be attributed to the presence of platinum, while gold can be considered responsible for structural stability. In addition, molecule dissociation is observed in the cases of H2, HCl, CH4, SO, and SO2 when Pt atoms are involved. Thus, two-dimensional Au9, Pt9, and Au18Pt18 show low adsorption energies against common molecules, reflecting adsorption energies observed in small Au and Pt clusters. These results demonstrate that Au18Pt18 can successfully utilize the low adsorption energies associated with platinum while preserving the integrity of the surface structure using gold atoms, making it possible to adsorb desired molecules using select areas of the Au18Pt18 surface.

Effects of anisotropic properties on bursting behavior of rectangular cup with a V-notch

Effects of mechanical anisotropic properties on bursting failure and its pressure of rectangular deep-drawn cup fabricated by using AA3005-H14 thin sheet are investigated to utilize for electrolyte container of lithium-ion secondary batteries. The V-notch shape with a depth of 0.1 mm and an angle of 20.0˚ is defined on the rectangular cup, which has a thickness of 0.20 mm on the major surface and that of 0.30 mm on the minor surface. With the measured mechanical properties by uni-axial tensile tests and the defined V-notch geometry, a series of numerical prediction models considering isotropic, planar and normal anisotropic characteristics, are built-up and the bursting simulations are performed. Thereafter, the bursting fracture behavior is investigated by adopting ductile fracture criterion proposed by Cockcroft and Latham. The results predicted for the planar and the normal anisotropic models show that the bursting fracture pressure is well matched to 0.400 MPa, and the isotropic and the planar anisotropic models present a bursting fracture height of about 4.95 mm and 4.92 mm, respectively. A series of experimental investigations are undertaken to verify the bursting deformation that had been predicted. The bursting pressure and its height during experimental verifications are shown to be in good agreement with each variation of about 5.88% and roughly 0.20% with respect to the numerical results obtained using the planar anisotropic model.

The demise of the early Eocene greenhouse – Decoupled deep and surface water cooling in the eastern North Atlantic

Early Paleogene greenhouse climate culminated during the early Eocene Climatic Optimum (EECO, 50 to 53Ma). This episode of global warmth is subsequently followed by an almost 20 million year-long cooling trend leading to the Eocene-Oligocene glaciation of Antarctica. Here we present the first detailed planktic and benthic foraminiferal isotope single site record (δ13C, δ18O) of late Paleocene to middle Eocene age from the North Atlantic (Deep Sea Drilling Project Site 401, Bay of Biscay). Good core recovery in combination with well preserved foraminifera makes this site suitable for correlations and comparison with previously published long-term records from the Pacific Ocean (e.g. Allison Guyot, Shatsky Rise), the Southern Ocean (Maud Rise) and the equatorial Atlantic (Demerara Rise). Whereas our North Atlantic benthic foraminiferal δ18O and δ13C data agree with the global trend showing the long-term shift toward heavier δ18O values, we only observe minor surface water δ18O changes during the middle Eocene (if at all) in planktic foraminiferal data. Apparently, the surface North Atlantic did not cool substantially during the middle Eocene. Thus, the North Atlantic appears to have had a different surface ocean cooling history during the middle Eocene than the southern hemisphere, whereas cooler deep-water masses were comparatively well mixed. Our results are in agreement with previously published findings from Tanzania, which also support the idea of a muted post-EECO surface-water cooling outside the southern high-latitudes.