Surface Veneer Research Articles

MECHANICAL PROPERTIES OF PF AND MUF BONDED JUVENILE HYBRID EUCALYPTUS PLYWOODS PRODUCED IN GHANA

To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Ghana was the objective of this research. The samples for the experiment were prepared and tested according to GS EN 326-1, GS EN 310, GS EN 314-1, and GS EN 314 -2. The data obtained were analysed using the factorial ANOVA analysis. The mean results obtained for the various treatments were MOE (6520 – 7638 N/mm2), MOR (53.29 – 60.56 N/mm2, shear strength (2.47 – 5.51 N/mm2), failure (72 -90%) and density (725 – 748 kg/m3). The orientation of the surface veneer caused variations among treatments whiles the adhesives PF and MUF largely did not cause any variations among treatments. This study has proven that it is possible to produce sufficiently strong and resistant plywood from the juvenile wood of eucalyptus.

Development of higher weatherproof plywood using lathe check of veneer ―Penetration of impregnating paint into a plywood whose surface veneer is attached inside (pith side) out and its changes after 10 months exposure―

Development of higher weatherproof plywood using lathe check of veneer ―Penetration of impregnating paint into a plywood whose surface veneer is attached inside (pith side) out and its changes after 10 months exposure―

Performance properties of plywood composites reinforced with carbon fibers

In this study, carbon fibers were added as a reinforcement layer between wood veneers bonded with melamine-urea–formaldehyde (MUF) resin to improve properties of standard wood laminated composite. Two different fiber orientations were tested, being parallel and perpendicular to the veneers. In addition, two different locations were evaluated. Internal, surrounding the core veneer, and external, below the surface veneer. Flexural properties, water absorption, density, cutting force, and tensile shear strength were tested and evaluated. Results showed that reinforcing plywood panels with carbon fibers increased both MOR and MOE. The cutting force showed better results for composite panels with CF in a perpendicular orientation. Moreover, the water uptake and thickness swelling after 24 h showed better results for fibers in the core layer, either parallel or perpendicular.

A Song Below Water by Bethany C. Morrow

Reviewed by: A Song Below Water by Bethany C. Morrow Fiona Hartley-Kroeger A Song Below Water by Bethany C. Morrow In folklore and fiction, monsters represent very real human anxieties and fears, and the supernatural is often a way of talking about painful subjects. Morrow’s YA debut deftly twines myth and folklore with realism, creating a compelling narrative in which the fantastical elements, drawn from a range of folkloric and mythological traditions, amplify contemporary issues of gender, race, and power that Black women and girls face in their everyday lives. The story unfolds through alternating first-person narration by Tavia and Effie, who live in a Portland, Oregon much like ours—but in a world where sprites wreak mischief, elokos charm all and sundry, and gargoyles come and go as they please. The girls are sisters in all but blood; their mutual love and individual journeys of identity are the twin poles around which the action revolves. Tavia is a siren, with a voice that can command and compel listeners with her siren calls. Sirens’ voices are considered threats to be suppressed and controlled, especially since sirens are now exclusively Black women in a world that already demonizes them in multiple ways. “Now that it’s just us, the romance is dead,” remarks Tavia. “Instead of inspiring songs and stories, now our calls inspire defensive anger. Our power’s not enchanting or endearing anymore; it offends.” While her parents would prefer that Tavia suppress her power, she’s seeking out her grandmother’s spirit to learn more about her voice and how to use it. Effie’s journey is about understanding who and what she is. Haunted by a traumatic incident in her past, in which a group of childhood friends were turned to stone, Effie finds solace in swimming and performing as Euphemia the Mer at the local Renaissance Faire. Unanswered questions about her parents, the mysterious Hidden Scales tent at the Ren Faire, and literal and metaphorical discomfort in her own skin drive her to seek answers from the reticent grandparents who raised her after her mother’s death and sent her to live with Tavia’s family. This magical realist world has as much realism as magic: the murder of a Black woman rumored to be a siren, police violence at a protest, and the self-outing of a popular YouTube star as a siren bring urgency to the girls’ need to answer questions about who they are and how their voices can empower as well as endanger them. Friend and frenemy dynamics and boy troubles ring true alongside the mystery of the hunky gargoyle who perches on the girls’ roof. Morrow skillfully balances acerbic social commentary and relatable teen angst with understated, heart-pounding tension: for instance, faux-woke behavior from friends and teachers receives the disdain it deserves, while a “random” police stop incident is utterly [End Page 419] harrowing; currents of racism and misogyny are palpable beneath a surface veneer of civility that threatens to erupt into violence at any moment. Though it’s unflinching in its depiction of the trauma of silencing and disempowerment, the novel is far from a grimdark misery fest. It offers supportive versions of community in Tavia and Effie’s sisterhood, their complicated but loving families, Tavia’s gospel choir that lets her use her voice safely, and Effie’s Ren Faire home where performing frees her to be another version of herself. Morrow’s prose flows easily between the sisters, giving each her own voice and finding magic in self-knowledge as well as in the fantastic. There’s plenty here to interest a broad audience: this is a must-read for readers committed to a nuanced understanding of racial (in)justice and for fans of Nalo Hopkinson and Nnedi Okorafor. (See p. 440 for publication information.) Copyright © 2020 The Board of Trustees of the University of Illinois

Specific features of 3, 6-bis (4-hydroxy phenyl)-piperazine-2, 5-dione (BHPPD) diphenolic monomer and compered with toxic industrial bisphenol-A (BPA): DFT calculation

In this study calculations of IR spectra, Mullikan charge analysis, molecular structures, energy optimization, molecular masses, dipole moments, polarizations, atomic electronic charges, HOMO and LUMO energies, gap energies, hardness, softness, electron affinities, chemical potentials and investigate of electro static potentials have been performed. The density functional theory (DFT) within the B3LYP method and 6-31G/6-311G* basis sets on BPA and BHPPD were used. A comprehensive comparison between the two methods was presented. The computations demonstrate that the 3, 6-bis (4-hydroxy phenyl)- piperazine-2, 5-dione (BHPPD) monomer can be viewed as another biodegradable diol which might be utilized as substitutes for the mechanically utilized poisonous diphenols, for example, bisphenol-A (BPA). BHPPD can be utilized as a part of the outline of biodegradable materials as grocery contact surface veneer coatings for jars, metal containers capping, defensive veneers and completions, vehicle parts, glues, aviation applications and as a covering for PVC tubes. The examination amongst BPA and BHPPD demonstrated that the novel nonpoisonous integrated fragrant diol has better physicochemical and poisonous properties contrasted with that of BPA.

Effect of surface carbonization on mechanical properties of LVL

The wood veneer from Monopetalanthus species was heated under different temperatures (120 °C, 160 °C, 200 °C, and 240 °C) and then laminated as the surface of laminated veneer lumber (LVL). Bending modulus of elasticity (MOE), modulus of rupture (MOR), and impact toughness (IT) of the LVL were tested. The results showed that the failure location became scattered as the surface veneer carbonization temperature was increased and that the failure mode changed from split failure in the control and the 120 °C samples to crack failure in the 160 °C, 200 °C, and 240 °C samples under the bending load. Fiber tearing was visible in all five sample types, where the length of the tearing fibers became shorter with increased surface heating temperature under impact load. The carbonization temperature of surface veneer had a minimal effect on the MOE but a considerable effect on the MOR and IT, and the MOR mainly showed a downtrend. The IT loss decreased as the surface veneer carbonization temperature was increased.

Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts

Much of our knowledge of early metazoan evolution is derived from unmineralized death mask or endorelief mold and cast fossils in Ediacaran clastic sedimentary rocks. This record is often regarded as a unique ‘Ediacaran taphonomic window’; however, the prevalence of soft-bodied molds and casts in Paleozoic clastic rocks has been increasing, begging an extension, or modification, to our understanding of this preservational motif. Chief amongst such fossils are eldonids, a non-biomineralized group of stem deuterostomes. Because eldonids are also preserved as compressed or flattened fossils from deposits like the Burgess Shale, Chengjiang and Kaili, they offer a comparative case study for evaluating the taphonomic fidelity of mold/cast-style preservation during this interval. EDS and Raman microspectroscopic analysis of Ordovician and Devonian eldonid molds and casts, and comparison with Burgess Shale eldonids, suggests the mold/cast taphonomic style produces significantly lower fidelity of fossil preservation. We propose that eldonid mold/cast fossils are preserved by the adsorption of reduced iron ions onto tissues composed primarily of high molecular weight (HMW) biopolymers which require enzymatic degradation prior to decay. Nucleation and growth of aluminosilicates and/or sulfides around these adsorbed ions forms a fossilizable surface veneer, preserving a death mask mold. More labile tissues could not be fossilized in this mold and cast style. Ediacaran mold and cast fossils from South Australia, the White Sea region of Russia, Namibia, and Newfoundland exhibit preservational characteristics consistent with this new proposed model. Analysis of their preservational mode suggests that the first metazoans, which would have lacked HMW biopolymeric tissues, could not have been fossilized in this particular style. Thus, understanding the origin and earliest evolution of the Metazoa requires a focus on alternative modes of fossilization.

Preparation of hydro-thermal surface-densified plywood inspired by the stiffness difference in “sandwich structure” of wood

Inspired by stiffness difference in the “sandwich structure” of earlywood and latewood, surface-densified (SD) plywood was manufactured based on a hydro-thermal approach. A series of veneer moisture contents (MCs) and hot-pressing temperatures were selected to prepare the SD plywood. Great surface densification was observed according to density distribution through plywood thickness. The densification was attributed to the thermal softening and mechano-sorptive behavior of constituents in the wood cell wall. A greater degree of surface densification could be achieved at higher hot-pressing temperatures or higher surface veneer MCs. Final MCs of the SD plywood met the requirement of the Chinese national standard. No significant variation was observed for the bonding strength among SD and control (CK) plywood. Mechanical properties – including modulus of rupture (MOR), modulus of elasticity (MOE) and hardness – of the SD plywood were significantly higher than the CK plywood. The enhancements of MOR, MOE and hardness could be attributed to its high-density surfaces. The greatest increment of MOR, MOE and hardness was 54, 104 and 144%, respectively. Comparing to some domestic Chinese hardwood species, SD plywood possessed greater surface hardness with less average density. The results indicated that, inspired by the stiffness difference in the “sandwich structure” of wood, preparation of the SD plywood based upon hydro-thermal treatment is feasible.

난연특성을 가지는 EVA/Intumescent/나노클레이 복합재료 제조 및 교호집성재(Cross Laminated Timber) 적용 기술

최근 들어 늘어나고 있는 도시형 화재 사고와 건축 외장재에 따른 화재 피해 사례의 증가에 따라 난연처리기술의 중요성이 부각되고 있다. 특히, 목재를 기반으로 한 건축재료의 활용에 있어서 난연처리기술은 더욱 중요하게 평가되고 있다. Intumescent 시스템은 비할로겐계 난연처리기술의 하나로, 발포와 탄화층 형성을 통하여 난연성을 구현하는 시스템이다. 본 연구에서는 Intumescent 시스템을 적용하기 위해 Ethylene vinyl acetate (EVA)를 매트릭스로 채용하여 복합재료를 제조하였다. Intumescent 시스템의 난연특성을 강화하기 위해 나노클레이를 함께 적용하였다. Intumescent 시스템과 나노클레이 기술을 함께 적용한 복합재료를 시트상의 시험편으로 가공한 후, 이를 활용하여 표면의 난연특성이 강화된 새로운 구조의 교호집성재를 제작하였다. Intumescent 시스템을 적용한 복합재료의 연소특성 평가에서 최대 열방출량이 효과적으로 감소되는 것을 확인할 수 있었다. 표면에 부착된 구조에 따라 CLT는 두 단계에 걸친 연소 현상이 발생했다. 또한, 심부 연소 과정에서 최대 열방출률이 크게 감소하는 경향을 확인할 수 있었다. 이러한 특성은 목재의 연소과정에 있어 연소 확산지연효과가 있을 것으로 판단된다. 표면단판에 대한 난연처리기술 및 복합재료 적용 최적화 기술을 통해 보다 화재특성이 개선된 CLT 구조체 개발이 가능할 것으로 기대된다. Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

Impact-generated winds on Mars

Bright and dark wind streaks across Mars record wind patterns related to atmospheric circulation. In some cases these streaks represent erosion of a surface veneer; in others, they indicate sand grains mobilized by strong vortices shed off of positive relief, such as crater rims. While many streaks change length or orientation over time, others not only remain unchanged but also may indicate a completely different wind direction. These permanent streaks could reflect past circulation patterns in response to conditions related to orbital forcing (e.g., Thomas and Veverka, 1979; Veverka et al., 1981). Here, however, we focus on a subset of permanent wind streaks unrelated to global circulation, rather to impact-generated winds that can extend more than 500km away from the crater. Nighttime images from the Mars Odyssey's Thermal Emission Imaging System (THEMIS) reveal certain large craters (> 15km in diameter) having sets of thermally bright streaks that radiate from certain fresh impact craters. These streaks extend from pre-existing topographic highs (crater rims, wrinkle ridges) beyond the continuous ejecta deposits to more than 6 crater radii, unrelated to secondary craters. For illustration, this contribution primarily focuses on the 20km-diameter Santa Fe crater in Chryse Planitia. Context Camera (CTX) images reveal that these streaks correspond to zones of erosion. The thermally bright rays in nighttime images correlate with regions where coarser materials have been exposed, not always resolved even in HiRISE images. Models of the impact process indicate impact-generated vapor most likely generated intense winds that scoured the region, well before arrival of secondary craters and later ejecta run-out flows. Pre-existing relief (such as crater rims) disturbed this flow and generated intense cross-flow instabilities resulting in long parallel streaks.

Waviness of beech sliced veneer

In wood industry, decorative veneer is a product of high added value. Although the technological process of sliced veneer is well known, its quality and price depend on many technological parameters of production, particularly on the quality of logs. The research, which was focused on the influence of visual defects of beech (Fagus sylvatica L.) logs and the impact of climatic conditions in the drying phase of sliced veneer on the surface veneer waviness, was conducted in an industrial environment. The results indicate that the largest share of waved veneer was cut from cracked logs (71%) and less from curved logs (20%). The veneer was sorted manually by experienced controllers from this branch of industry. Their subjective criteria can affect the accuracy of classification of veneer and, consequently, the research results. Therefore, the possibility of using 3D camera for measuring veneer waviness and grading the veneer into quality classes was examined.

Evaluation of Mechanical Properties of Reinforced Poplar Laminated Veneer Lumber

Three types of reinforcement materials, a carbon fiber-reinforced polymer (CFRP) sheet, a glass fiber-reinforced polymer (GFRP) mesh, and a composite of the CFRP sheet and GFRP mesh, were used to reinforce poplar laminated veneer lumber (LVL), and the multi-step hot-pressing method was also applied. The mechanical properties, i.e., modulus of rupture (MOR), modulus of elasticity (MOE), and horizontal shear strength (HSS), of the reinforced LVL were investigated, as well as the effects of lay-up location of the CFRP sheet/GFRP mesh composite. The results indicated that applying the multi-step hot-pressing method and incorporating the CFRP sheet, GFRP mesh, and the CFRP sheet/GFRP mesh composite noticeably improved the MOR and MOE under horizontal and vertical loadings. Only the multi-step hot-pressing method was able to greatly improve the HSS of reinforced LVL under both loading modes. The improved effect of the three kinds of reinforcing materials on the mechanical properties was ordered as follows: CFRP sheet/GFRP mesh composite > CFRP sheet > GFRP mesh. Locating the CFRP sheet/GFRP mesh composite closer to the surface veneer layer yielded the best mechanical properties for the reinforced poplar LVL.

Uniform functional structure across spatial scales in an intertidal benthic assemblage

To investigate the causes of the remarkable similarity of emergent assemblage properties that has been demonstrated across disparate intertidal seagrass sites and assemblages, this study examined whether their emergent functional-group metrics are scale related by testing the null hypothesis that functional diversity and the suite of dominant functional groups in seagrass-associated macrofauna are robust structural features of such assemblages and do not vary spatially across nested scales within a 0.4 ha area. This was carried out via a lattice of 64 spatially referenced stations. Although densities of individual components were patchily dispersed across the locality, rank orders of importance of the 14 functional groups present, their overall functional diversity and evenness, and the proportions of the total individuals contained within each showed, in contrast, statistically significant spatial uniformity, even at areal scales <2 m2. Analysis of the proportional importance of the functional groups in their geospatial context also revealed weaker than expected levels of spatial autocorrelation, and then only at the smaller scales and amongst the most dominant groups, and only a small number of negative correlations occurred between the proportional importances of the individual groups. In effect, such patterning was a surface veneer overlying remarkable stability of assemblage functional composition across all spatial scales. Although assemblage species composition is known to be homogeneous in some soft-sediment marine systems over equivalent scales, this combination of patchy individual components yet basically constant functional-group structure seems as yet unreported.

Process and Structure of Electromagnetic Shielding Plywood Composite Laminated with Carbon Fiber Paper

Carbon fiber paper (CFP), a type of flexible planer electromagnetic shielding material with thin thickness, low density, and good adhesion property and permeability, was laminated with wood veneer to produce a plywood composite with good shielding effectiveness (SE). It was found that a hot-press pressure of 1.2 MPa and a double-sized adhesive concentration of 380 g/m2 were most appropriate for the production of CFP plywood composites. SE of plywood composite laminated with single layer CFP was better than that before hot pressed, which result from the formation of three-dimensional and smaller conductive carbon fiber circuitries. The space between two-layer CFPs and the thickness of the surface-layer veneer had significant influence on SE. The SE of the composites laminated with two-layer CFPs was significantly higher than those with one-layer CFPs. The SE in the frequency range of 30 MHz to 1 GHz reached above 30 dB depending on the space between two-layer CFPs and the thickness of the surface veneer, which was sufficient SE for commercialization and the use of plywood composites.

Fungal resistance and physical–mechanical properties of beech plywood having durable veneers or fungicides in surfaces

Improvement of insufficient fungal resistance of beech plywood for wet conditions was examined by: (1) incorporation of durable oak (Quercus robur) or black locust (Robinia pseudoacacia) surface veneers instead of beech (Fagus sylvatica) ones; (2) primordial treatment of beech surface veneers with 0.5, 1, 1.5 and 3 % solutions of fungicides DDAC, IPBC, Propiconazole and Tebuconazole; (3) additional treatment of beech plywood with the same fungicides. The anti-fungal efficiency of these three methods, applied to five-layer plywood boards glued with phenolic resin, was assessed either by decay test with two brown rot fungi (Coniophora puteana and Serpula lacrymans) and one white rot fungus (Trametes versicolor) using edge protected specimens according to modified ENV 12038, or by mould test with two microscopic fungi (Aspergillus niger and Penicillium brevi-compactum) according to modified EN 15457. The durability of beech plywood significantly increased after incorporation of black locust veneers into the surface layers, and also thanks to organic fungicides (0.5 % IPBC, Propiconazole or Tebuconazole, and 1.5 % DDAC) present in the surfaces. Other selected properties of beech plywood were sometimes influenced positively (e.g., soaking due to less permeable black locust and oak surface veneers) or negatively (e.g., shear strength due to fungicides).

MAHLI at the Rocknest sand shadow: Science and science‐enabling activities

AbstractDuring Martian solar days 57–100, the Mars Science Laboratory Curiosity rover acquired and processed a solid (sediment) sample and analyzed its mineralogy and geochemistry with the Chemistry and Mineralogy and Sample Analysis at Mars instruments. An aeolian deposit—herein referred to as the Rocknest sand shadow—was inferred to represent a global average soil composition and selected for study to facilitate integration of analytical results with observations from earlier missions. During first‐time activities, the Mars Hand Lens Imager (MAHLI) was used to support both science and engineering activities related to sample assessment, collection, and delivery. Here we report on MAHLI activities that directly supported sample analysis and provide MAHLI observations regarding the grain‐scale characteristics of the Rocknest sand shadow. MAHLI imaging confirms that the Rocknest sand shadow is one of a family of bimodal aeolian accumulations on Mars—similar to the coarse‐grained ripples interrogated by the Mars Exploration Rovers Spirit and Opportunity—in which a surface veneer of coarse‐grained sediment stabilizes predominantly fine‐grained sediment of the deposit interior. The similarity in grain size distribution of these geographically disparate deposits support the widespread occurrence of bimodal aeolian transport on Mars. We suggest that preservation of bimodal aeolian deposits may be characteristic of regions of active deflation, where winnowing of the fine‐sediment fraction results in a relatively low sediment load and a preferential increase in the coarse‐grained fraction of the sediment load. The compositional similarity of Martian aeolian deposits supports the potential for global redistribution of fine‐grained components, combined with potential local contributions.

Whewellite and its key role in living systems

Whewellite is the dominant mineral in the plant kingdom, and one of the most important minerals within the surface veneer of our planet. It is intimately associated with the functioning of living systems and plays a significant role in the carbon cycle. The monohydrate form of calcium oxalate, whewellite, commonly occurs along with the less stable dihydrate form (weddellite). These minerals are not restricted to plants—humans may be painfully aware of whewellite as the principal mineral phase of urinary stones. Geologically whewellite is found in diagenetic settings, hydrothermal veins and in meteorites (carbonaceous chondrites), nevertheless the mineral is massively under‐represented in the geological column given its high productivity in the biosphere. Reasons for this are explored, and it is argued that a better understanding of the relationship between whewellite and host organisms will have benefits for agriculture, medicine, and potentially strategies for CO2 sequestration.

Suitability of Melia dubia (malabar neem wood) for plywood manufacture

The plywood industries had been utilizing plantation timbers and other lesser known timbers for making plywood because of non-availability of conventional timbers. Melia dubia (malabar neem wood) has been identified as one of the fast growing species that would be suitable for plywood making and a study was carried out for determining its suitability for plywood manufacture. Investigations have shown that type-B surface veneers could be produced by peeling and the veneers could be dried without major degrades. Gluing and bonding properties have been studied and found that the panels made using urea formaldehyde and phenol formaldehyde adhesives meets the requirement of MR and BWR grade plywood as per relevant specification.

Detection of CO in Triton's atmosphere and the nature of surface-atmosphere interactions

Triton possesses a thin atmosphere, primarily composed of nitrogen, sustained by the sublimation of surface ices. The goal is to determine the composition of Triton's atmosphere and to constrain the nature of surface-atmosphere interactions. We perform high-resolution spectroscopic observations in the 2.32-2.37 $\mu$m range, using CRIRES at the VLT. From this first spectroscopic detection of Triton's atmosphere in the infrared, we report (i) the first observation of gaseous methane since its discovery in the ultraviolet by Voyager in 1989 and (ii) the first ever detection of gaseous CO in the satellite. The CO atmospheric abundance is remarkably similar to its surface abundance, and appears to be controlled by a thin, CO-enriched, surface veneer resulting from seasonal transport and/or atmospheric escape. The CH$_4$ partial pressure is several times larger than inferred from Voyager. This confirms that Triton's atmosphere is seasonally variable and is best interpreted by the warming of CH$_4$-rich icy grains as Triton passed southern summer solstice in 2000. The presence of CO in Triton's atmosphere also affects its temperature, photochemistry and ionospheric composition. An improved upper limit on CO in Pluto's atmosphere is also reported.

Medium timescale stability of tidal mudflats in Bridgwater Bay, Bristol Channel, UK: Influence of tides, waves and climate

This paper presents the results of an 11-year study into mudflat elevation changes within the intertidal zone at Stert Flats in Bridgwater Bay, Somerset. This site is located in the outer Severn Estuary/inner Bristol Channel which is a macro-hypertidal regime dominated by physical processes, characterized by strong tidal currents, high turbidity and a significant degree of exposure to wind generated waves. Two transects of stakes were installed perpendicular to the coast, extending seawards 300 m from the edge of the saltmarsh onto the mudflats, against which variations in accretion or erosion could be measured. The mudflats themselves consisted of an underlying consolidated clay of Holocene age and a surface veneer of fluid mud and/or mobile sand patches which varied both spatially and temporally. Mudflat development was recorded over both short-term (monthly/seasonal) and medium-term (inter-annual) timescales. The results display a significant degree of scatter over all timescales. Such variability in response may be expected in such a dynamic system where noise can be attributed to a combination of factors such as the mobility of surface fluid mud and sand patches and the migration of the underlying ridge–runnel drainage network. Despite this, the expected short-term variations related to neap–spring tidal conditions and seasonal influences were observed at a number of locations on the transects although these were weakly expressed. The over-riding feature of the profiles is a consistent long-term trend of erosion which appears to be masking shorter term trends within the dataset. Viewed over the 11-year period, the changes in mudflat elevation closely match the pattern of the index of the North Atlantic Oscillation (NAO) during the 1990s, suggesting a strong climatic control over mudflat development on a medium-term/decadal scale. Most profiles display a strong erosional trend during the early 1990s when the NAO index was positive. The erosional trend peaked in 1995 at a time during which the values for monthly winter mean significant wave height were notably high. Between 1996 and 2001 the profiles generally record accretion and the data display significant variability. This corresponds with a shift to a strongly negative and then weakly positive NAO index phase. The fact that such a general atmospheric factor correlates so closely with medium timescale elevation change is attributed to relative weakness of biological binding and burrowing at this site, and more-so to the overwhelming dominance of the physical regime, especially the tidal current and the wind–wave regime. Both the background erosional trend and the influence of the index of the NAO in controlling mudflat evolution have important implications relating to coastal management. These are discussed in relation to coastal defence measures, morphological response to major civil engineering projects (e.g. Severn Tidal Power Barrage) and the prospect of climate change, sea-level rise and a possible increase in strength of NAO conditions in the future.