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Abstract Holbox Island is a contemporary hotspot for global tourism. Here, long-term coastal exploitation and increasing anthropogenic activities threaten coastal habitats and resources. The impact of these activities is exacerbated by the lack of a management plan for the past 24 years, until October 2018. An interdisciplinary approach that integrates fishers' traditional knowledge was used to determine how small-scale fisheries (SSF) exploitation contributed to the decline of resources over time. Open interviews with community members and surveys of fishers' perspectives on fisheries overexploitation and practices as well as knowledge of fishing sites were collected. Over one hundred fishing sites were documented that were once very productive. Furthermore, over 40 species were highly fished (e.g. , Carcharhinidae, Shpyrnidae, Pristidae, Cheloniidae) over the past 50 years. Survey results allowed for the construction of maps with baseline information of coastal exploitation. Additional data from archaeozoological remains (n= 545) of aquatic fauna identified 33 families of exploited taxa, of which finfish (e.g. , Haemulidaea, Ariidae, Serranidae), sharks (e.g. , Carcharhinidae), and sea turtles were the most abundant. Fishers and literature sources (n= 50) document Holbox's contemporary issues, including overfishing, illegal fishing, and accelerated tourism development. These types of data (fishers' perspectives, interdisciplinary literature, and archaeozoological data) were combined using historical ecology techniques and geospatial tools to obtain novel baseline information on SSF exploitation. This information is essential for conservation managers and scientists to meet the management needs of Holbox's natural and social capital, which can assure the future provision of coastal ecosystem services to humans. Graphical abstract Holbox Island is a contemporary hotspot for global tourism. Here, long-term coastal exploitation and increasing anthropogenic activities threaten coastal habitats and resources. The impact of these activities is exacerbated by the lack of a management plan for the region. An interdisciplinary approach that integrates fishers' traditional knowledge was used to determine how small-scale fisheries (SSF) exploitation contributed to the decline of resources over time. Open interviews with community members and surveys of fishers' perspectives on fisheries overexploitation and practices as well as knowledge of fishing sites were collected. Over one hundred fishing sites were documented that were once very productive. Furthermore over 40 species were highly fished (e.g., Carcharhinidae, Shpyrnidae, Pristidae, Cheloniidae) over the past 50 years. Survey results allowed for the construction of maps with baseline information of coastal exploitation. Additional data from archaeozoological remains (n= 545) of aquatic fauna identified 33 families of exploited taxa, of which fmfish (e.g., Haemulidaea, Ariidae, Serranidae), sharks (e.g., Carcharhinidae), and sea turtles were the most abundant. Fishers and literature sources (n= 50) document Holbox's contemporary issues, including overfishing, illegal fishing, and accelerated tourism development. These types of data (fishers' perspectives, interdisciplinary literature, and archaeozoological data) were combined using historical ecology techniques and geospatial tools to obtain novel baseline information on SSF exploitation. This information is essential for conservation managers and scientists to meet the management needs of Holbox's natural and social capital, which can assure the future provision of coastal ecosystem services to humans. fx1 Highlig hts • Holbox Island (HI), is a hotspot spot for international tourism which is leading to increasing threats for biodiversity and habitat conservation. • Combining fishers' traditional knowledge, interdisciplinary literature, and archaeozoological data; spatial and qualitative baseline information on small-scale fisheries exploitation at HI is provided and can help develop management actions. • Finfish, sharks, and sea turtles, were the most abundant exploited taxa in archaeozoological remains. For the contemporary history of HI over 40 highly fished species (e.g. Carcharhinidae, Pristidae) were documented in the past 40 years. • Fishers' traditional knowledge documented over 100 fishing sites which allowed the construction of informative maps about small-scale fisheries exploitation. • Fishers' and literature sources report increasing fishing effort, overfishing, illegal fishing and social conflicts related to the use of coastal resources. [ABSTRACT FROM AUTHOR]

Lithomargic clay has low plasticity and therefore makes it difficult to form ceramic bodies without addition of binder using conventional sintering technique. Plasticity can be improved by addition of clay binders. However, clay binders increase SiO 2 content and thus lower the refractoriness of the sintered compacts. In this study, mullite was fabricated from lithomargic clay using spark plasma sintering without addition of clay binder. The mullite compacts were produced at a varying temperature range of 1300–1400 °C for a holding time of 300 s under pressure of 30 MPa. Densification and physico-mechanical properties were studied. Densification and hardness values of mullite increased with temperature while apparent porosity and water absorption decreased with temperature. The hardness of mullite sintered at 1400 °C reached 1112 HV. Mullite produced has the potential to be used for lightweight applications. [ABSTRACT FROM AUTHOR]

The processing of low-grade sulphide gold ores generates a significant volume of tailings which impacts the environment. The reuse of sulphide mine tailings as a substitute for sand in construction mortar offers the advantages of reducing costly tailings management whilst promoting sustainable construction. However, the acceptance of mine tailings as alternative sand for construction depends on its effective stabilization during use. In this study, hardened mortar cubes have been prepared by varying the substitution of river sand with sulphide mine tailings. The stabilization effects of cement, cement-lime and cement-pozzolana on sulphide mine tailings have been investigated. The water demand, slump behaviour, bulk density, water absorption, compressive strength, and X-ray diffraction (XRD) were examined to observe the physical and mechanical properties of the mortars. The water demand and bulk density decreased whilst the slump value and water absorption increased with increased tailings replacement. The highest 28-day compressive strength of 12.2 MPa was achieved at 25% tailing replacement with a cement binder. Cement proved to be the best binder for the stabilization of the tailings which was followed by cement-pozzolana and cement-lime respectively. • Sulphide mine tailing is used as a partial replacement for river sand in mortar. • Cement, lime and pozzolana were used as binders to stabilize the tailings. • The physical and mechanical properties of the mortar were examined. • Maximum compressive strength of 12.2 MPa was achieved at 25% tailing replacement. [ABSTRACT FROM AUTHOR]

Abstract: Lithomargic clay underlying Awaso bauxite deposits consists mainly of kaolinite and minor fractions of gibbsite. Gibbsite, useful as a source of alumina, was separated from kaolinite. Gibbsite was added to lithomargic clay in various amounts, using Mfensi clay as a binder, and fired at 1350 oC for 2h. Linear firing shrinkage, density, porosity, water absorption and cold crushing strength were used to characterize the fired bricks. The mineralogical compositions in the fired bricks were analyzed by X-ray diffraction techniques. The results showed that increasing the gibbsite amount up to 40wt% increased the firing shrinkage and density whilst the apparent porosity and water absorption values decreased. Increasing the gibbsite amount enhanced mullite and corundum formation whilst the formation of free-silica phases was inhibited. The cold crushing strength increased linearly with increasing gibbsite content. [Copyright &y& Elsevier]

Abstract: Lithomargic clay until now has not been utilised to produce refractory bodies due to its low plasticity. In this work, the development and evaluation of fireclay refractory material produced from lithomargic clay deposit has been studied by addition of clay binder. Three formulations were prepared by mixing, semi-dry moulding, drying and firing at temperatures ranging from 1200 to 1400°C. The fired samples were investigated to determine their physical properties such as bulk density, apparent porosity, linear firing shrinkage, and cold crushing strength. The chemical and mineralogical compositions were also determined. The results show that the linear firing shrinkage values were within limits acceptable for refractory clays. The cold crushing strength increases as temperature increased to 1400°C. Cold crushing strength increased with increasing binder content. The increase of the highly refractory phases (cristobalite and mullite) and the densification of the bricks due to the presence of fluxing agents were responsible for the high cold crushing strength values. The investigated properties indicate that lithomargic clay underlying bauxite deposits could be used to produce fire clay aluminosilicate refractories. [Copyright &y& Elsevier]

Electrochemiluminescence (ECL) is the generation of light during a chemical reaction with at least one of the reagents being generated in situ at an electrode. Recently, a host of methods have been developed employing ECL reactions as an analytical technique where one of the ECL reagents is the analyte. Electrochemiluminescent reactions involving aqueous metal ions can offer an alternative method for quantitation of dissolved metals. Previous work developed an ECL system using 1,10-phenanthroline as an ECL reagent in conjunction with Cd2+ ions providing sufficient emission for reliable cadmium detection. This paper explores the effects of ligand modification, choice of surfactant, and the interaction between the surfactant and the co-reactant tripropylamine (TPA). The effectiveness of the reagents tested can be ranked as phenanthroline, bathophenanthroline salt, terpyridine, dimethylphenanthroline, and bipyridine in order of decreasing Cd2+ specific ECL emissions. The non-ionic surfactants Triton X-100, Thesit, and Nonidet P40 were surveyed. [Copyright &y& Elsevier]

The influence of cobalt based and zirconia mixed binder additives on the mechanical properties and tribological characteristics of WC based spark plasma sintered cermet composites was investigated. Varied weight proportions of zirconia stabilized with yttria along with constant weights of 9Co/WC–4.5CO–2Cr–5Ni metallic binder were blended with WC, consolidated and sintered using spark plasma sintering process. The composites produced were characterized using SEM and XRD analyses, density measurements, mechanical properties and wear test evaluations. The results show that the use of the mixed binder additives did not significantly affect the densification process as relative densities above 92% (7.5% less than that achieved using only the Co based metallic binders) were achieved using SPS processing. However, the grain size was observed to increase with increase in zirconia content in the mixed bond composites, and the hardness values decreased with increase in zirconia content. The toughness and fracture toughness showed significant improvement with the addition of zirconia. Also the coefficient of friction for the mixed binder sintered composites were on the average lower than that of the cermet composites without zirconia. Pseudoplastic properties characterized by the presence of delaminations were the primary wear mechanism observed for the zirconia containing cermets; while pits and wear groove formations were observed in the cermets without zirconia. [ABSTRACT FROM AUTHOR]

To study the effect of ZrO 2 on the corrosion and wear behaviour of NiTi adaptive coatings, AISI 316 stainless steel samples were laser coated with NiTi–ZrO 2 admixed powders. The corrosion behaviour of the composite coatings was studied in 1 M H 2 SO 4 using polarisation methods. Both dry and wet wear tests were conducted on composite coatings at different sliding loads using pin-on-disc tribometer setup. The corrosion resistance of the laser coatings depended strongly on the chemical composition and microstructure. The results showed an increase in the corrosion rate, as ZrO 2 content increased. Dry wear rate improved, whilst wet wear rate decreased with increased ZrO 2 content. [ABSTRACT FROM AUTHOR]

The mechanical properties and wet sliding wear behavior of spark plasma sintered WC based composites consolidated using 10Ni/7Ni–3Cr (metallic binders) and varied wt.% (15 and 20%) zirconia stabilized with yttria (ceramic binder) as mixed binder additives were investigated. Relative density measurement, SEM analysis, hardness and Palmquist toughness characterization were used to assess the properties of the produced composites. The results show that the use of mixtures of 10Ni, 7Ni–3Cr and yttria stabilized zirconia binder additives for the consolidation of the WC based composites yielded relative densities above 94%. Significant drop in hardness values was observed in the sintered composites with the addition of 15 and 20% zirconia. But the Palmquist toughness improved with the addition of zirconia for both composite grades. The fracture toughness for the WC–10Ni based yttria stabilized zirconia composites appeared to be invariant to the addition of zirconia while the WC–7Ni–3Cr composite grades showed a slight improvement in the fracture toughness with an increase in the zirconia content. The fracture toughness of the WC–10Ni based yttria stabilized zirconia composites was slightly superior to that of the WC–7Ni–3Cr based yttria stabilized zirconia composites. The addition of zirconia resulted in a significant reduction of the coefficient of friction of the WC–10Ni based yttria stabilized zirconia composites but resulted in the increase of the coefficient of friction of the WC–7Ni–3Cr based yttria stabilized zirconia composites. [ABSTRACT FROM AUTHOR]

Abstract: The tribocorrosion characteristics of laser deposited titanium–nickel–zirconia composite coatings onto AISI 316 substrates have been investigated. Feedstock powders were blended at varying compositions and deposited onto AISI 316 using Nd:YAG high power laser beam at varying scan speeds. The relationships between laser speed, structure and tribocorrosion properties of the synthesised composite coatings were studied. The corrosion and tribocorrosion behaviour of the coatings was studied in 1M H2SO4 solution using a potentiodynamic polarisation technique. The coatings displayed fine and slightly porous structures with relatively well dispersed constituent elements. The Ti–Ni coatings deposited under 0.0067m/s had the highest corrosion resistance while addition of 5% zirconia to the Ti–Ni coatings significantly improved its tribocorrosion resistance. [Copyright &y& Elsevier]

[Display omitted] • Two-stage activation was used to synthesize oxygen-rich interconnected carbon. • High purity activated carbon with high surface area was synthesized. • A high energy density supercapacitor device was assembled. • The device successful lit an LED bulb during real-life practical applications. In this work, carbonization and subsequent activation procedures were adopted to synthesize waste shea butter shells into oxygen-rich interconnected porous activated carbon (SAC_ x, x is the mass ratio of KOH used for activation). The SAC_1.5 electrode material showed outstanding electrochemical performance with high specific capacitance (286.6 F/g) and improved rate capability, owing to various synergistic effects originating from a high specific surface area (1233.5 m2/g) and O-rich content. The SAC_1.5-based symmetric device delivered an impressive specific capacitance of 91.6 F/g with a high energy density of 12.7 Wh/kg at 0.5 A/g. The device recorded 99.9 % capacitance retention after 10,000 charge-discharge cycles. The symmetric supercapacitor device successfully lit an LED bulb for more than 1 h, signifying the potential of bio-waste as an efficient carbon precursor for electrode material in practical supercapacitors. This work offers an efficient, affordable, and environmentally friendly strategy for potential renewable energy storage devices. [ABSTRACT FROM AUTHOR]

• 2205 stainless steel is fast replacing other grades of stainless steel. • Compressive stress is dominant in the austenite phase. • Dislocation accumulation around the grain boundary resulted in increased corrosion. • Residual stress promotes the formation of pits. The use of 2205 duplex stainless steel (2205 DSS) in the petrochemical and nuclear industries is fast replacing carbon steel and other convectional alloys due to its excellent corrosion resistance and improved mechanical properties it offers. The effect of residual stress on corrosion behaviour of hot and cold rolled 2205 DSS in a chloride environment is investigated. As received hot and cold rolled duplex stainless-steel samples were characterized using a scanning electron microscope (SEM) for microstructural phase analysis. Residual stresses of varying percentages (20, 40, and 60%) were applied to duplex stainless steel samples machined to micro tensile dimensions. The residual stress analysis of the necked region was analyzed using Bruker D8 Advance X-ray diffractometer, while potentiodynamic polarization was carried out in 3.5 wt% NaCl to access the corrosion integrity of the necked region. The center and average principal stress analysis (S11 and S22) of hot and cold-rolled stainless steel in the necked region showed the deformation of austenite and ferrite phases due to tensile pulling with more tensile stress in the austenite phase. SEM micrographs of corrosion substrates revealed the dominance of corrosion in the austenite phase within the necked region in hot rolled samples. [ABSTRACT FROM AUTHOR]