Obvious Break Research Articles

Durability of glass fiber reinforced thermoplastic polypropylene composite bars under the coupling effect of seawater and sea sand concrete environment and sustained bending

AbstractThe long‐term interfacial shear strength (IFSS) and flexural strength of GFPP bars under the coupling effect of bending and immersion in the simulated seawater and sea sand concrete (SWSC) solution were studied by an acceleration experiment. Three temperatures and three bending stress levels (0%, 9.8%, and 29.4% of the maximum flexural strain of GFPP bars) were used to accelerate the experiment. Results indicate that the degradation of mechanical properties of GFPP bars is relatively sensitive to the immersion temperature. Low bending stress did not accelerate the degradation of GFPP bars compared with unbent GFPP bars while high bending stress dramatically accelerated the degradation. Microscopic tests found there is corrosion of glass fibers and debonding between glass fibers and polypropylene but no obvious chain breaks of polypropylene occurred. Based on the Arrhenius theory, long‐term stable retention rates of the IFSS of GFPP bars with zero and low bending stress immersed in the simulated SWSC solution are 42.4% and 52.3%.Highlights Low‐stressed GFPP bars degraded similarly or even slower than unbent GFPP bars. GFPP bars degraded mainly due to interfacial debonding and fiber corrosion. Long‐term IFSS of GFPP bars under a coupling effect was predicted.

Weak-Edge Extraction of Nuclear Plate Fuel Neutron Images at Low Lining Degree

Neutron imaging is an effective nondestructive testing (NDT) technique widely applied to detect structural defects and the enrichment of nuclear fuel elements due to its high penetration and nuclide-sensitive properties. Since the fuel element pellet is sealed in the cladding, the transmission imaging result is a superposition of the two parts. Therefore, the attenuation of neutrons by the cladding is interference that must be considered in the enrichment analysis. It is necessary to extract and separate cladding and pellets using an edge extraction method. However, the low neutron cross-section of the cladding material (e.g., aluminum and zirconium) leads to poor grayscale contrast at the cladding edge in the imaging result, and the intensity of the cladding edge is significantly lower than that of the pellet edge. In addition, affected by the noise from the imaging environment, the boundaries of targets are further blurred, making edge detection more challenging. Traditional detection algorithms extract the weak edges of cladding incompletely, and the results are discontinuous, with obvious edge breaks and missing areas. This paper proposes a method to extract edges in neutron images based on phase congruency (PC). This study utilized the classical perceptual field model to improve contrast at weak edges. The enriched edge map was generated using our PC model from six directions, allowing more weak edges to be detected accurately. The non-maximum suppression ensured precise localization and avoided edge breaks. Furthermore, the edge results were optimized by eliminating noise through morphological operations. The experimental results demonstrate that the proposed method effectively detects the weak edges of the cladding, is superior in accuracy and integrity to traditional detection, and is able to obtain stable and reliable results with different materials of neutron images. The edge integrity improved by 64.1%, and the edge localization accuracy reached 94.3%. The extracted edge information is useful in the next stage of the high-precision enrichment analysis.

Experimental investigation on the wave-oscillating buoy interaction and wave run-up on the buoy

The interaction between a wave and an oscillating buoy is complex, and it directly affects the stability, working state, and efficiency of the buoy. In this study, an experimental investigation of the interaction between a wave and an oscillating buoy (including wave breaking, wave run-up, and the relative motion between waves and buoys) is conducted under constant power take-off (PTO) values. The wave conditions selected in the experiment are all obtained from measured data on the Qingdao coast, China. The experimental results show that when the wave steepness is greater than 0.0597, there is an obvious wave breaking in front of the oscillating buoy and that the steepness of the critical wave decreases with an increase in PTO. When the relative damping force is 0.101. In addition, an empirical formula based on the wave steepness, the PTO value, and the wave run-up is proposed in accordance with the M5’ model tree. The results obtained in this study contribute to an increased understanding of the development of wave energy from buoys. In turn, this improvement in understanding will inform the design and deployment of buoys in real-life scenarios.

Influence of Target Properties on Wall Slumping in Lunar Impact Craters Within the Simple‐To‐Complex Transition

AbstractThe 15–20 km crater diameter range on the Moon spans simple to transitional to complex crater morphologies. Simple craters in this range are only in the highlands. Transitional craters that contain localized slumps are scattered across the lunar surface. Most craters with localized slumps in the highlands superpose pre‐impact topography with obvious slope breaks. We interpret this as a condition favorable for post‐excavation internal slumping. However, some of these craters formed on terrains with topographic variation like the settings of simple craters: flat or gradually sloping surface, or degraded structures of older craters such as rims and terraces. To resolve the conundrum of two morphologies on one terrain type, we performed investigations of the local geology and topography of the inferred pre‐impact terrains. We assessed if the localized slumping in the craters happened during or well after crater formation, looked for spatial variations in the strength of the highlands crust, detected topographic breaks (through elevation data) that were unnoticeable in the optical data, and examined rim circularity. Our findings corroborate the influence of pre‐existing slopes on mass wasting along crater walls. Most of the craters with localized slumps have walls superposing topographic breaks that slope toward the crater interior. These walls are located near the uphill sector of the rims which initiated localized slumping. Most simple craters were found to have formed on surfaces with topographic breaks/slopes that face away from the adjoining crater walls, so that any immediate mass wasting would likely be outside the crater cavity.

High-Pressure Combustion Characteristics of Hydroxyl-Terminated Polybutadiene Propellants

Combustion mechanisms of propellants under high pressures are necessary to solve the problems of a high burning rate pressure exponent in high-pressure solid rocket motors. In this study, the combustion characteristics of hydroxyl-terminated polybutadiene (HTPB) propellants were investigated by analyzing the burning rate, the quenched surface, and the combustion wave up to pressures of 28 MPa. The results showed that the pressure exponent presented an obvious break above 17 MPa, which increased from below 0.4 to approximately one. The characteristic pressure where the exponent break occurred decreased from 19.00 to 17.90 MPa with the increase of coarse ammonium perchlorate (AP) particles and decreased from 18.73 to 16.96 MPa with the addition of octogen. Coarse-AP particles exposed on the burning surface recessed relative to the binder below the characteristic pressure and protruded from the binder above the characteristic pressure. This finding was attributed to the difference in the local mass transfer between the gas phase and the burning surface under high pressures. An important finding of this study was the decline at the AP/HTPB interface above the characteristic pressure, indicating that the local heat transfer might play a crucial role in the pressure exponent break of HTPB propellants under high pressures.

Effect of Mg microalloying on elevated-temperature creep resistance of Al–Cu 224 cast alloys

The influence of microalloying with Mg (0–0.36 wt%) on the elevated-temperature strength and creep resistance of Al–Cu 224 cast alloys was investigated. The Mg-containing alloys yielded finer and denser θ′ precipitates after high-temperature stabilization (300 °C/100 h) than the Mg-free alloy, which improved the yield strength at both room temperature and 300 °C. Compressive creep tests were conducted at 300 °C over a wide range of the applied stresses (45–100 MPa). The results showed that the creep resistance increased with increasing Mg content at any fixed applied stress, and the alloy with 0.36 wt% Mg exhibited the best creep resistance among the four alloys studied. During creep deformation, the θ′ precipitates continued to coarsen. However, Mg microalloying greatly stabilized the θ′ precipitates in the matrix by slowing down the coarsening process. An obvious break was observed in the creep rate curves with different stress exponents (n). Below the break in the low-stress regime (LSR), stress exponent (n) was ∼3, whereas it increased to 9–12 above the break in the high-stress regime (HSR). In the LSR, the creep was controlled by the dislocation climbing, and it transformed into the Orowan looping in the HSR.

On-Site Full-Scale Load Test and Reliability Evaluation of Prefabricated Bridge Substructure for “Pile–Column Integration”

The application of prefabricated bridge structures is of great significance to building industrialization, which can realize the green construction and maintenance process of low energy consumption and low emission as well as the normal operation of transportation in time, and effectively realize the green development requirements. However, the substructure of a conventional prefabricated bridge usually needs to cast a bearing platform between pier and column, and may not give full play to the advantages of prefabricated bridge construction. Given the engineering characteristics that most of the pile foundations in the bridge design of this engineering project are end-bearing piles, in which the pile foundation is not deep and the pile column is not high, the assembly process of “pile–column integration” has been proposed in this study. Aiming at the reconstruction and expansion project of the Qinzhou–Beihai section in the Lanzhou–Haikou expressway, the test site with representative geological conditions was firstly selected. The pile–column structure of the bridge can be completed by prefabricated pile foundation, pier, and cap beam based on the integral assembly installation method. The vertical compressive static load test, horizontal static load test, and reliability test of pile–column connection were introduced in detail to analyze whether the bearing capacity and connection effect of pile–column can meet the requirements. Test results showed that the limit value and corresponding characteristic value of the vertical compressive bearing capacity and horizontal critical load of a single pile could meet the design requirements. The displacement curve of single pile No. 5 at the flange connection position under various loads of the test pile does not have an obvious angle break, and there is no sudden change in the slope, indicating that the flange connection quality is good. Due to many interference factors and some abnormal strain measurement data, the strain data are suggested as auxiliary to the displacement results. The findings of static load testing and connection reliability in this study proved the feasibility of this prefabricated bridge substructure “pile–column integration”, which can provide a reference for the rapid construction of bridges.

Local symmetry predictors of mechanical stability in glasses.

The mechanical properties of crystals are controlled by the translational symmetry of their structures. But for glasses with a disordered structure, the link between the symmetry of local particle arrangements and stability is not well established. In this contribution, we provide experimental verification that the centrosymmetry of nearest-neighbor polyhedra in a glass strongly correlates with the local mechanical stability. We examine the distribution of local stability and local centrosymmetry in a glass during aging and deformation using microbeam x-ray scattering. These measurements reveal the underlying relationship between particle-level structure and larger-scale behavior and demonstrate that spatially connected, coordinated local transformations to lower symmetry structures are fundamental to these phenomena. While glassy structures lack obvious global symmetry breaking, local structural symmetry is a critical factor in predicting stability.

Occurrence morphology of bitumen in Dengying Formation deep and ultra-deep carbonate reservoirs of the Sichuan Basin and its indicating significance to oil and gas reservoirs

Abundant bitumen can be discovered in the wells of Upper Sinian Dengying Formation in the Sichuan Basin and their peripheral outcrops sections. As the cracking product of a paleo-oil reservoir, the occurrence morphologies and distribution characteristics of bitumen in carbonate reservoirs can indicate the preservation, migration and other key information of (paleo-) oil and gas reservoirs. In order to provide reference and basis for the deep and ultra-deep oil and gas exploration in the Sichuan Basin and the basins in western China, this paper systematically studies the occurrence morphological characteristics of bitumen in deep and ultra-deep carbonate reservoirs in well Gaoshi 1 of the Sichuan Basin by carrying out thin section observation, scanning electron microscope-energy spectrum analysis and fluid inclusion organic geochemical analysis on the cores of the fourth member of Dengying Formation (Deng 4 Member). In addition, the coupling relationship between the occurrence morphology of bitumen and the key event of hydrocarbon accumulation is revealed. And the following research results are obtained. First, solid bitumen in the Deng 4 Member deep and ultra-deep reservoir has two types of occurrence morphology. The first type of bitumen adheres to pore walls in the shape of a rim or exists in pores in the form of sticky branch (e.g., Wells Chuanshen 1 and Gaoshi 1). There are more obvious shrinkage fractures and residual pores generated by in-situ thermal cracking in this type of bitumen. And combined with fluid inclusion and burial thermal history, it can effectively indicate that a paleo-gas reservoir has been preserved so far since the paleo-oil reservoir was thermally cracked into carbonaceous bitumen. The second type of bitumen is distributed in intra- and inter-neogenic mineral crystals in pores disorderly in the shape of grain and band (e.g., Wells Mashen 1 and Wutan 1) and it has obvious breaking edges. It reveals that after a paleo-oil reservoir was thermally cracked into carbonaceous bitumen, the paleo-gas reservoir suffered blowdown and gas escape and neogenic fluid minerals moved into reservoirs to fill in pores. In conclusion, the occurrence morphologies and distribution characteristics of bitumen in deep and ultra-deep carbonate reservoirs can effectively indicate the hydrocarbon accumulation and evolution process of paleo-oil and gas reservoirs.

The outermost stellar halo of NGC 5128 (Centaurus A): Radial structure

Context.The extended stellar halos of galaxies contain important clues for investigating their assembly history and evolution.Aims.We investigate the resolved stellar content and the extended halo of NGC 5128 as a function of galactocentric distance, and trace the halo outward to its currently detectable limits.Methods.We usedHubbleSpace Telescope images obtained with the WFPC2, ACS, and WFC3 cameras equipped withF606WandF814Wfilters to resolve individual red giant branch (RGB) stars in 28 independent pointings across the halo of NGC 5128. The stellar halo analysis for 14 of these pointings is presented here for the first time. Star counts from deepVIcolor-magnitude diagrams reaching at least 1.5 mag below the tip of the RGB are used to derive the surface density distribution of the halo. The contamination by Milky Way stars is assessed with a new control field, with models, and by combining optical and near-IR photometry.Results.We present a new calibration of the WFC3F606W + F814Wphotometry to the ground-basedVIphotometric system. The photometry shows that the stellar halo of NGC 5128 is dominated by old RGB stars that are present in all fields. TheV-band surface brightness of fields changes from 23 to 32 mag arcsec−2between the innermost field only 8.3 kpc from the galaxy center to our outermost halo fields, which are located 140 kpc away from the center along the major axis and 92 kpc along the minor axis. Within the inner ∼30 kpc, we also find evidence for a 2 − 3 Gyr old population traced by asymptotic giant branch stars that are brighter than the tip of the RGB. This population contributes only up to 10% in total stellar mass if it is 2 Gyr old, but a larger fraction of 30 − 40% is required if its age is 3 Gyr. The stellar surface density profile is well fit by a classicr1/4curve or a simple power-law form ∼r−3.1over the full radial range, with no obvious break in the slope, but with large field-to-field scatter. The ellipticity measured from integrated-light photometry in the inner parts,e = (b/a) = 0.77, flattens toe = 0.54 ± 0.02 beyond 30 kpc. Considering the flattening of the outer halo, the projection of the elliptical isophote on the semimajor axis for our most distant field reaches nearly 30 effective radii.

Fragmentation dynamics of CH3Clq+ (q = 2,3): theory and experiment.

A combined theoretical and experimental study of the dissociation of the di- and trication of the CH3Cl molecule has been performed. Experimentally, these multi-charged ions were produced after interactions of a CH3Cl effusive jet with a mono-energetic beam of H+ or Ar9+ projectile ions. Theoretically, we mapped the multi-dimensional potential energy surfaces of CH3Cl2+, H2CClH2+ and CH3Cl3+ species in their electronic ground and electronically excited states using post-Hartree-Fock configuration interaction methods. In addition to the obvious bond-breaking ionic fragments (i.e. H+ + CH2Cl+, H+ + CH2Cl2+ and CH3+ + Cl+), the formation of H2+ (+CHCl+ or CHCl2+), H3+ (+CCl+) and HCl+ (+CH2+) was observed upon bond rearrangement after ion impact of CH3Cl. The interaction strength of the incident projectiles is found to affect the relative yields on the observed dissociation channels, however, it has no effect on the kinetic energy releases of the fragmentation pathways. For the observed dissociation channels, plausible formation mechanisms were proposed. These reaction pathways take place on the ground and/or electronic excited potential energy surfaces of the doubly and triply charged CH3Cl ions, where spin-orbit and vibronic couplings are in action. Moreover, this work suggests that the mechanisms undertaken may depend on the multiply charged ion preparation by valence or inner-shell single photon photoionization, fast ion beam impact or ultrafast intense laser ionization.

Research on Roof Fracture Characteristics of Gob-Side Entry Retaining with Roof Cutting and Non-pillar Mining in Thick Coal Seam, China

Based on the S1201-2 large height mining in the 2–2 coal seam of Ningtiaota colliery with on-site microseismic measurement, physical simulation and theoretical analysis methods, this paper explores the rule of roof movement in thick coal seams with roof cutting and non-pillar (hereinafter referred to as RCN-P) mining, so as to obtain scientific and effective theoretical basis for entry support and to summarize the regional structural characteristics and dynamic periodic fracture characteristics. As can be seen from microseismic events, the entry roof is featured by "two zones and one line" along the horizontal direction, namely, the crack generation area, the roof movement area. Additionally, and the obvious lateral breaking of the entry roof on the coal wall is a typical feature of the thick coal seam with RCN-P mining. The roof is vertically divided into "three zones", the crack generation area, the roof movement area and the crack development area. The roof cutting activity mainly affects the overburden activity within the basic roof height range, which is also the roof movement area. In addition, the distribution frequency and the intensity of microseismic events indicate the roof periodic breaking characteristics. The "breaking pressure relief,” “advanced crack development,” and “the limit breaking state” of roof breaking corresponds to the initial, middle, and final stage of breaking in the periodic weighting process, respectively. Compared with the normal mining, the RCN-P mining reduces the periodic weighting length and increases the pressure strength. As is shown in the physical simulation experiment, the basic roof and the cutting control layer in the "regional structural characteristics" constitute the “large” and “small” structures with RCN-P mining. The basic roof key layer is the core to control the stability of the strata, and the breaking process from the cantilever beam to the short masonry beam of the roof-cutting control layer is the main cause of the entry stress. Correspondingly, the basic structure model of “short masonry-hinged” roof was proposed and the calculation method of support was established for the entry with RCN-P mining in thick coal seam, providing a research foundation for scientific and effective rock formation control.

Research on the nonlinear dynamic relationship between FDI and CO2 emissions in the "One Belt, One Road" countries.

This study examines the relationship between FDI and CO2 emissions in a nonlinear framework using data from countries along the "One Belt, One Road" from 1979 to 2017 as the sample. First, the linear analysis method was used to examine the stability of FDI and CO2 emissions in countries along the "One Belt, One Road." In addition, the BDS (Brock-Dechert-Scheinkman test) method and nonlinear Granger causality test are used to investigate the nonlinear relationship between variables. Finally, a threshold vector autoregressive model (TVAR) is used to analyze the dynamic change mechanism between China's FDI and CO2 emissions, and a threshold vector error correction model (TVECM) is used to test how the variables respond to deviations from equilibrium. Then, the Markov switching model is used to test the robustness of the results. The research results show that China, India, South Africa, and other countries all have a nonlinear causal relationship between FDI and CO2 emissions. At the same time, the comovement of FDI and CO2 emissions in China has obvious structural break features, which are relevant for the underlying regime. Furthermore, the results also show that the adjustment process of the FDI toward equilibrium is highly persistent in the first regime, and CO2 emissions will adjust to an equilibrium state at a faster speed in the second regime. Therefore, this paper puts forward different policy suggestions for different countries. For China, we should pay attention to the long-term benefits of FDI and introduce high-tech green FDI.

UBM-guided scleral buckling for Schwartz-Matsuo syndrome with tear of nonpigmented epithelium of the ciliary body: a case report

BackgroundTears in Schwartz-Matsuo syndrome are generally confirmed by preoperative ophthalmoscopic examination. A case of Schwartz-Matsuo syndrome with a tear detected by ultrasound biomicroscopy (UBM) and treated by UBM-guided scleral buckling was reported, and its mechanism was analysed.Case presentationA 40-year-old Chinese man presented with blurry vision and intermittent eye pain in his left eye for three days. The visual acuity of the left eye decreased from 20/20 to 20/40, and the intraocular pressure (IOP) fluctuated dramatically from 24.0 mmHg to 56.7 mmHg at the first visit. Gonioscopy revealed that the chamber angle remained open. A macula-involving inferior retinal detachment extending from 4:30 to 9:30 with no obvious causative break was observed through ophthalmoscopic examination. However, a single small tear was detected at the nonpigmented epithelium of pars plana of the ciliary body at approximately 7–8 o’clock by UBM. The loss of photoreceptor outer segments and ellipsoid zone and the existence of macular microcysts in the inner and outer nuclear layers were observed in the detached macula by optical coherence tomography. Then, he underwent successful scleral buckling guided by UBM. Three months later, the retina was flat with normal IOP, and the best corrected visual acuity of his left eye gradually improved to 20/25. UBM confirmed the closure of the tear.ConclusionsTear of the nonpigmented epithelium of the ciliary body is a rare condition associated with Schwartz-Matsuo syndrome. UBM plays a key role in detecting occult tears of the nonpigmented epithelium of the ciliary body, guiding scleral buckling surgery, and observing the closure of the tear postoperatively.

Spatio-Temporal Assessment of Global Precipitation Products over the Largest Agriculture Region in Pakistan

Spatial and temporal precipitation data acquisition is highly important for hydro-meteorological applications. Gridded precipitation products (GPPs) offer an opportunity to estimate precipitation at different time and resolution. Though, the products have numerous discrepancies that need to be evaluated against in-situ records. The present study is the first of its kind to highlight the performance evaluation of gauge based (GB) and satellite based (SB) GPPs at annual, winter, and summer monsoon scale by using multiple statistical approach during the period of 1979–2017 and 2003–2017, respectively. The result revealed that the temporal magnitude of all the GPPs was different and deviate up to 100–200 mm with overall spatial pattern of underestimation (GB product) and overestimation (SB product) from north to south gradient. The degree of accuracy of GB products with observed precipitation decreases with the increase in the magnitude of precipitation and vice versa for SB precipitation products. Furthermore, the observed precipitation revealed the positive trend with multiple turning points during the period 1979–2005. However, the gentle increase with no obvious break point has been detected during the period of 2005–2017. The large inter-annual variability and trends slope of the reference data series were well captured by Global Precipitation Climatology Centre (GPCC) and Tropical Rainfall Measuring Mission (TRMM) products and outperformed the relative GPPs in terms of higher R2 values of ≥ 0.90 and lower values of estimated RME ≤ 25% at annual and summer monsoon season. However, Climate Research Unit (CRU) performed better during winter estimates as compared with in-situ records. In view of significant error and discrepancies, regional correction factors for each GPPs were introduced that can be useful for future concerned projects over the study region. The study highlights the importance of evaluation by the careful selection of potential GPPs for the future hydro-climate studies over the similar regions like Punjab Province.

Exploring High-energy Emission from the BL Lacertae Object S5 0716+714 with the Fermi Large Area Telescope

Abstract We present the results of an extensive γ-ray data analysis of the emission from the blazar S5 0716+714 with the primary motivation to study its temporal and spectral variability behavior. In this work, we extract a 10 days binned γ-ray light curve from 2008 August 4 to 2016 April 27 in the energy range of 0.1–300 GeV and identify six outburst periods with peak flux of >4 × 10−7 ph cm−2 s−1 from this highly variable source. The brightest flares are identified by zooming in these outburst periods to 1 day binning and using the Bayesian Blocks algorithm. The fastest variability timescale is found to be 1.5 ± 0.3 hr at MJD 57128.01 ± 0.01 with a peak flux above 100 MeV of (26.8 ± 6.9) × 10−7 ph cm−2 s−1. No hint of periodic modulations has been detected for the light curve of S5 0716+714. During the outburst phases, the γ-ray spectrum shows an obvious spectral break with a break energy between 0.93 and 6.90 GeV energies, which may be caused by an intrinsic break in the energy distribution of radiating particles. The five highest-energy photons, with E > 100 GeV, imply that the high-energy emission from this source may originate from a moving emission region in a helical path upstream in the jet. The spectral behavior and temporal characteristics of the individual flares indicate that the location of the emission region lies in the sub-parsec scale (r γ < 0.85 pc).

Avalonian arc-to-platform transition in southeastern New England: U-Pb geochronology and stratigraphy of Ediacaran Cambridge “argillite,” Boston Basin, Massachusetts, USA

High-precision CA-TIMS 206Pb/238U zircon dates clarify the age and tectonic significance of the Cambridge Formation which is poorly exposed in the Boston Basin, eastern Massachusetts, but transected by ∼50 km of tunnels beneath the mainland and Boston Harbor. The youngest detrital zircon in a sample from the northern Braintree Weymouth Tunnel establishes a maximum depositional age of 584.09 ± 1.98 Ma, consistent with sources in sills of that age in underlying Roxbury Conglomerate. A 551.22 ± 0.20 Ma ash bed from the Mystic Quarry in Somerville, Massachusetts lies near the top of an approximately 5350 m thick, dominantly argillaceous section measured in subsurface cross sections. These were constructed from attitudes reported in pre-1960 tunnels and from mapping logs obtained from tunnels completed decades later during the federally ordered clean-up of Boston Harbor. A 488.58 ± 0.16 Ma aplite sill intruding argillite ∼800 m above the ash bed sets the minimum depositional age on the north side of the Basin. A tighter constraint comes from trilobite-bearing strata of the lower Cambrian Weymouth Formation located south of Boston that overlies the Cambridge Formation without obvious break in the Braintree Weymouth Tunnel. If Cambridge deposition was continuous after 584 Ma, the depositional interval would exceed 40 million years. An estimated ∼20 Ma depositional hiatus seems more likely because the base of the Cambridge Formation appears to define a regional unconformity above which argillite rests variously on magmatic arc-related units of both the 595 to 584 Ma Roxbury Conglomerate and the 597 to 593 Ma Lynn-Mattapan Volcanic Complex. Cambridge deposition set in once arc activity in more northerly “West” Avalonian terranes extending through Atlantic Canada to the Avalon Peninsula, Newfoundland had given way to wrench faulting and bimodal magmatism. This regime is manifested structurally in Boston-area tunnels by later-reactivated normal faults in which hanging wall blocks of Cambridge argillite were originally downthrown relative to older footwall units. Pyroclastic volcanic textures and thin basaltic flows with soft sediment contacts are present in argillite of the City Tunnel Extension, and whole rock major element and REE compositions reveal mixed terrigenous and volcanic components deposited under marine conditions throughout the Basin. Proposed sources for the latter are voluminous eruptions recorded in the 560 to 550 Ma Coldbrook Group in New Brunswick9s Caledonia terrane.

Investigation of processing factors affecting flexible heating wire by coating polyester yarns with carbon nanotubes

A method for preparing a flexible heating wire coated with carbon nanotubes on a surface of a polyester yarn is proposed in view of the problems of poor flexibility and water washing resistance of the existing heating wire. Based on the flexible heating wire forming system, the orthogonal test method was used to study the effects of process parameters such as solution concentration and polymer content on the formation of flexible heating wire; the prepared heating wire was subjected to resistance measurement, microscopic morphology observation, heating and washing resistance tests. The results show that the optimal parameter parameters for the preparation of flexible hot wire is A3B3C2D2. In this combination, the polymer content is 15 g/L and the heating wire resistance is 180.5 Ω/cm. Moreover, the photomicrograph shows that the surface has a conductive layer composed of polymer and carbon nanotubes, which has no obvious protrusions and breaks; the surface of the parallel mesh structure can obtain a heating temperature of 52.2°C at a voltage of 12 V; the resistance of heating wire does not increase with latter washing after the first washing.

‘A New Era’ is always Dawning. A Linguistic Biography of a Border Crosser and Doppelgänger from Bukovina in the Second Half of the 20th Century

This article argues that it was not only physical borders that challenged people’s biographies in the 20th century, but also shifts in ideology, discourse and predominant languages. I shall explore the biography of a man called Cornel, a native of Bukovina who was a communist cultural official in Romania’s capital Bucharest in the 1960s and who became a priest in the 1970s. I shall show that not only obvious breaks such as the beginning and end of communist rule, but ideological shifts too within Romanian communism prompted Cornel to thoroughly reassess himself. For Cornel, it was the ‘mini-cultural revolution’ of 1971 under the rule of Nicolae Ceaușescu that quickly convinced him to leave his job at the Romanian Ministry of Culture and reinvent himself as an Orthodox priest. But was his self-reinvention successful? A thorough analysis of his biography shows that his linguistic biography—oscillating between Romanian, Ukrainian and Russian—contains crucial elements of productive adaptation and continuity that enabled him repeatedly and successfully to circumvent borders imposed by newly emerging policies. His “third” identity as a writer has given him continuity and self-assurance.

Samspil máls og merkingar. Um litaheiti í íslensku táknmáli

Brent Berlin and Paul Kay brought a sea change in semantic studies of colour terms when they published their book Basic Color Terms in 1969. Up to that point the dominant view was that each language represented a unique conceptual organisation of the world, a view supported by the fact that the colour spectrum is a continuum which provides not obvious breaks for the purposes of naming. Despite the many criticisms of their work which have followed, their methodology has proven extremely influential and been widely adopted. The project Evolution of Semantic Systems, 2011–2012, adopted their methodology for a study of colour terms in the Indo-European languages and the Colours in Context project applied the same methods to a study of Icelandic Sign Language. Signed languages diff er in many ways from spoken languages but the results of this study suggest the broad organisation of the colour space is the same in Icelandic Sign Language, Icelandic and British English. The colour space is organised by a few dominant terms, largely the same as Berlin and Kay ́s original basic colour terms. Yet within that broad pattern is considerable microvariation, especially in the spaces between the dominant terms. There the characteristic patt erns of word formation in the language have a clear influence in colour naming strategies.