ABSTRACT Concrete may develop micro cracks and contains pores, both of which are extremely undesirable since they allow water and other harmful chemicals to enter the material easily. The Bacterial Self Compacting (BSCC), which continually deposits calcite in concrete, is one efficient method for sealing fissures. Microbiologically Induced Calcite Precipitation, or MICP, is the term used to describe this occurrence. The urease enzyme assists bacteria in the deposition of calcium carbonate (CaCO3). Because it is bio-based, environmentally safe, and long-lasting, the bacterial remediation method outperforms other methods. The high pH of concrete and the mechanical forces that occur during mixing require bacteria to provide resistance. The MICP-induced concrete has become a significant topic of study for high performance building. The utilization of bacteria for the production of bacterial SCC has received very little attention in India, and the durability properties of these mixtures have also received inadequate attention. Bacterial Self-Compacting Concrete (BSCC) of M60 grade, with bacteria as admixture along with flyash and silica fume. This research is to know about the workability, mechanical properties, durability and micro analysis of bacterial self-compacting concrete. The test results shows the bacteria of size 106 shows the best results in bacterial self-compacting concrete.

Abstract. Reef-forming cnidarians are essential for maintaining ecological balance. Unfortunately, coral reefs are endangered due to coral bleaching, which interrupts mutualistic symbiosis between Symbiodiniaceae algae and their coral hosts. Bleaching events result in very high coral mortality and the rapid deterioration of reef structures. Studies aimed at explaining the causes, mechanisms, and consequences of coral bleaching have been mainly conducted with anthozoans, while the impacts of thermal stress responsible for coral bleaching have been scarcely studied in hydrozoans, such as Millepora species (phylum Cnidaria, class Hydrozoa), which are the second most important reef-forming cnidarians. In the present study, the effects of thermal stress caused by the 2015-2016 El Niño on symbiont abundance, exoskeleton structure, and the biochemical composition of Millepora alcicornis were analyzed. Unbleached M. alcicornis specimens exhibited a higher abundance of Breviolum and Durisdinium species, which suggests that unbleached hydrocoral colonies might counteract thermal stress by hosting thermotolerant symbionts of the Durisdinium genus. Bleached hydrocorals exhibited lower levels of calcification than unbleached hydrocorals as well as changes in the microstructure of trabeculae and zooid pores. In contrast, thermal stress did not affect total calcium carbonate and carbohydrate content. Bleached tissues showed significantly higher levels of protein and refractory material, whereas their lipid content decreased considerably. The present study provides evidence that bleached M. alcicornis colonies suffered a decline in calcification and changes in the structure of their exoskeletons after being exposed to the 2015-2016 El Niño. The significant decrease in lipid content suggests that M. alcicornis primarily uses energy stores to maintain vital cellular processes at the expense of calcification.

Resumen. Los cnidarios formadores de arrecifes son esenciales en la ecología marina. Desafortunadamente, están amenazados por el fenómeno de blanqueamiento, el cual rompe la simbiosis mutualista entre algas de la familia Symbiodiniaceae y sus hospederos coralinos. El blanqueamiento causa un alto índice de mortalidad de corales y un rápido deterioro de las estructuras arrecifales. Los estudios dirigidos a explicar causas, mecanismos y consecuencias del blanqueamiento se han realizado principalmente con antozoos, mientras que los impactos del blanqueamiento de corales se han estudiado escasamente en especies de Millepora (phylum Cnidaria, clase Hydrozoa), que son los segundos constructores de arrecifes más importantes. En el presente estudio se analizó el efecto del estrés térmico causado por el evento El Niño 2015-2016 sobre la abundancia de simbiontes, la estructura del exoesqueleto y la composición bioquímica de Millepora alcicornis. Los especímenes sin blanquear de M. alcicornis contenían una mayor abundancia de especies de Breviolum y Durisdinium, lo que sugiere que las colonias de hidrocorales sin blanquear podrían estar contrarrestando el estrés térmico al albergar simbiontes termotolerantes del género Durisdinium. Los hidrocorales blanqueados mostraron niveles más bajos de calcificación y cambios en la microestructura de zooides y trabéculas. En contraste, el estrés térmico no modificó el contenido total de carbonato de calcio y carbohidratos en los hidrocorales. Los tejidos blanqueados mostraron niveles significativamente más altos de proteína y material refractario, mientras que su contenido de lípidos disminuyó considerablemente. El presente estudio muestra que las colonias blanqueadas de M. alcicornis sufrieron una disminución en la calcificación y cambios en la estructura de su exoesqueleto después de estar expuestas al estrés térmico provocado por el evento El Niño 2015-2016. La disminución significativa en el contenido de lípidos sugiere que M. alcicornis está utilizando sus reservas de energía principalmente para mantener sus procesos celulares vitales a expensas de la calcificación.

The thermal decomposition of carbonate minerals as pre-treatment before smelting reduces the energy requirement for smelting. It can also make the combustion of fossil fuels for heating unnecassary. Thermal decomposition may become important in reducing greenhouse gas emissions when producing ferromanganese alloys while simultaneously reducing electrical energy demand during smelting. A kinetic reaction rate model for the thermal decomposition of manganese ores is presented, based on published reaction rate kinetics for the decomposition of manganese oxides and calcium carbonate. The model was validated against thermogravimetric data for two carbonaceous manganese ore samples and one ferruginous manganese ore sample. The reaction rate model shows that carbonate minerals in the manganese ores are decomposed at temperatures above 900 °C while pyrolusite is decomposed at temperatures from 450 °C to 500 °C. Mn2O3 decomposes rapidly at 550 °C. Braunite decomposition at temperatures below 1000 °C was negligible. The presence of organic carbon in the samples led to further reduction of the samples during thermal treatment.

Resumen El carbonato de calcio está presente en muchas estructuras biológicas, como la concha de bivalvo, que se compone principalmente de dos polimorfos de CaCO3: calcita y aragonito. Sin embargo, existen otras formas de carbonato de calcio como vaterita y carbonato de calcio amorfo (ACC) que no se reportan comúnmente. La selección de polimorfos está influenciada por la concentración de sal, los iones cofactores y la presencia de proteínas de la matriz de la cubierta (SMP) que regulan la deposición de carbonato de calcio, entre otros factores. En este estudio, se evaluó la cristalización in vitro de carbonato de calcio de cuatro soluciones salinas diferentes (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) en dos molaridades (40 o 100 mM)con diferentes concentraciones la proteína Ps19 (0.2, 0.7 y 1.2 µg/µL) una proteína insoluble extraída de la concha de Pteria sterna, descrita anteriormente como promotora de la cristalización de plaquetas de aragonita. Las cristalizaciones in vitro mostraron que Ps19 es capaz de inducir la deposición de aragonita y calcita de forma dependiente de la dosis, pero también de vaterita en determinadas condiciones, actuando como promotor e inhibidor de la cristalización. Los resultados contribuyen a comprender cómo Ps19 controla la precipitación de polimorfos de calcio en el crecimiento de la capa prismática y de nácar de la concha de P. sterna.

Abstract Calcium carbonate is present in many biological structures such as bivalve shells, which is composed mainly of two CaCO3 polymorphs: calcite and aragonite. However, other forms of calcium carbonate exist like vaterite and amorphous calcium carbonate (ACC) that are not commonly reported. Polymorph selection is influenced by salt concentration, cofactor ions, and the presence of shell matrix proteins (SMPs) which regulates calcium carbonate deposition, among other factors. In this study, in vitro calcium carbonate crystallization of four different saline solutions (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) at two molarities (40 o 100 mM) was evaluated with increased concentrations of the Ps19 protein (0.2, 0.7 y 1.2 µg/µL), an insoluble extracted protein from the Pteria sterna shell, previously described as a promotor of aragonite platelet crystallization. In vitro crystallizations showed that Ps19 is capable to induce aragonite and calcite deposition in a dose-dependent manner, but also vaterite under certain conditions, acting as a promoter and inhibitor of crystallization. The results contribute to understand how Ps19 control precipitation of calcium polymorphs in the growth of the prismatic and nacre layer of the shell of P. sterna.

ABSTRACT Background. Sclerobionts (e.g., calcareous algae, bryozoans, polychaetes, mollusks, and barnacles) produce reef calcium carbonate (CaCO3). Their contribution is key to maintaining positive CaCO3 balances, especially in marginal reefs. Objective. To compare the production of CaCO3 by sclerobionts in two marginal reefs of the Mexican Pacific: Las Gatas (LG), in Zihuatanejo Guerrero Bay, and La Llave (LL), in Bahía de Los Angeles (Gulf of California). Methods. CAUs (Calcification/Accretion Units) were used to promote sclerobiont recruitment during two deployment times: 6 and 15 months. Results. The calcification rate was high at six months and then decreased due to rapid colonization and initial growth, followed by a decrease over time. Sclerobionts deposited 1.2 ± 0.4 kg CaCO3 m-2 yr-1 in LG, which represents 7% of the production of branching corals in the Mexican South Pacific (17.2 kg m-2 yr-1), while in LL, they deposited 2.1 ± 0.7 kg CaCO3 m-2 yr-1; equivalent to 20% of the production of massive corals in the area (10.1 kg m-2 yr-1). The groups that deposited most CaCO3 were mollusks and bryozoans in LG (up to 0.65 ± 0.16 kg m-2 yr-1) and barnacles in LL (up to 2.32 ± 0.35 kg m-2 yr-1). Conclusions. These results highlight the role of heterotrophs as secondary calcifiers both in LG, a site impacted by anthropogenic activity, and in LL, an area with low anthropogenic impact but high biological productivity associated with upwellings. This finding implies that the environmental conditions at the study sites limit the calcification of primary calcifiers (i.e., corals and CCA) but promote that of secondary calcifiers, with potential geomorphic repercussions.

RESUMEN Antecedentes. Los esclerobiontes (e.g., algas calcáreas, briozoos, poliquetos, moluscos, y balanos) participan en la producción de carbonato de calcio (CaCO3) arrecifal. Su contribución es vital para mantener balances de CaCO3 positivos, especialmente en arrecifes marginales. Objetivo. Comparar la producción de CaCO3 por esclerobiontes en un arrecife sujeto a estrés antropogénico - Las Gatas (LG), en la bahía de Zihuatanejo Guerrero, y otro bajo condiciones ambientales altamente fluctuantes - La Llave (LL), en Bahía de Los Ángeles (Golfo de California). Métodos. Se utilizaron CAUs (Calcification/Accretion Units) para promover el reclutamiento de esclerobiontes durante dos periodos de inmersión: 6 y 15 meses. Resultados. La tasa de calcificación fue alta a los 6 meses y luego disminuyó debido a la rápida colonización y crecimiento inicial seguido de una disminución con el tiempo. Los esclerobiontes depositaron 1.2 ± 0.4 kg CaCO3 m-2 año-1 en LG, lo que representa el 7% de la producción de corales ramificados en el Pacífico sur mexicano (17.2 kg m-2 año-1), mientras que en LL depositaron 2.1 ± 0.7 kg CaCO3 m-2 año-1, equivalente al 20% de la producción de corales masivos en la zona (10.1 kg m-2 año-1). Los grupos que más CaCO3 depositaron fueron los moluscos y los briozoos en LG (hasta 0.65 ± 0.16 kg m-2 año-1), y los balanos en LL (hasta 2.32 ± 0.35 kg m-2 año-1). Conclusiones. Estos resultados destacan el papel de los heterótrofos como calcificadores secundarios tanto en LG, un sitio impactado por actividad antropogénica, como en LL, un sitio con bajo impacto antropogénico, pero con alta productividad biológica asociada a surgencias. Este hallazgo implica que las condiciones ambientales en los sitios de estudio limitan la calcificación de los calcificadores primarios (i.e., corales y CCA) pero estimulan la de calcificadores secundarios, con potenciales repercusiones geomórficas.

ABSTRACT Background. Coral reefs provide several important geo-ecological functions essential for the sustainability of coastal human communities. However, during the last 50 years, reef ecosystems are experiencing rapid degradation caused by natural and anthropogenic disturbances. One consequence of the above has been the reduction in the carbonate production rate and the structural complexity of these systems. Particularly, the loss of key coral species in the construction of reefs has compromised the functionality of the ecosystem. Objective. In this study we used an adaptation of the ReefBudget methodology to measure the calcium carbonate budget in the reef of La Entrega, Oaxaca, Mexico. Methods. Six transects were carried out to estimate the abundance of eroding fish (25 x 4 m), sea urchins (25 x 2 m) and the composition of the benthos. Results. When carrying out the corresponding calculations, it was found that in La Entrega 13.72 kg m-2 year-1 (commonly referred as “G”) are produced, the endobioerosion (including erosion by sponges) calculated was 5.65 G. The sea urchin erosion is 0.12 G and that of fish is 0.73 G; the resulting net carbonate budget was 7.21 G. The accretion rate (vertical reef growth) at La Entrega reef was 7.07 mm yr-1. We consider it important to mention that the reef patch at La Entrega is relatively small (approximately 324 x 233 m) compared to formations in the Caribbean or Indo-Pacific regions. Conclusions. Net production at La Entrega is higher than estimated for most Caribbean reefs (2-4 G) but lower than that of the Indo-Pacific (5-14 G). Differences in the balance between regions are mainly associated with differences in the abundances of builder species in each region. According to what was modeled in this work, the La Entrega reef patch presents a sufficient accretion rate to deal with a possible rise in sea level under the RCP 4.5 and 2.6 scenarios (4 and 7 mm, respectively).

RESUMEN Antecedentes. Los arrecifes de coral proporcionan diversas funciones geo-ecológicas importantes esenciales para la sostenibilidad de las comunidades humanas costeras. Sin embargo, durante los últimos 50 años, los ecosistemas arrecifales están experimentando una rápida degradación ocasionada por perturbaciones naturales y antropogénicas. Una consecuencia de lo anterior ha sido la reducción de la tasa de producción de carbonatos y la complejidad estructural de estos sistemas. Particularmente, la pérdida de especies coralinas clave en la construcción de arrecifes ha comprometido la funcionalidad del ecosistema. Objetivo. En este estudio utilizamos una adaptación de la metodología ReefBudget para medir el balance de carbonato de calcio en el arrecife de La Entrega, Oaxaca, México. Métodos. Se realizaron seis transectos para estimar la de abundancia de peces erosionadores (25 x 4 m), erizos (25 x 2 m) y la composición del bentos. Resultados. Al realizar los cálculos correspondientes, se encontró que en La Entrega se producen 13.72 kg m-2 año-1 (unidades comúnmente referidas con “G”), la endobioerosión (incluida la erosión por esponjas) calculada fue de 5.65 G. La erosión por erizos es de 0.12 G y la de peces es de 0.73 G; el balance neto de carbonatos resultantes fue de 7.21 G. La tasa de acreción (crecimiento vertical del arrecife) en el arrecife de La Entrega fue de 7.07 mm año-1. Consideramos importante mencionar que el parche arrecifal en La Entrega es relativamente pequeño (aproximadamente 324 x 233 m) en comparación con las formaciones de regiones del Caribe o el Indo-Pacífico. Conclusiones. La producción neta en La Entrega es superior a la estimada en la mayoría de los arrecifes del Caribe (2-4 G) pero más baja que la del Indo-Pacífico (5-14 G). Las diferencias en el balance entre regiones están, principalmente, asociadas a las diferencias en las abundancias de especies constructoras en cada región. De acuerdo con lo modelado en este trabajo, el parche arrecifal de La Entrega presenta una tasa de acreción suficiente para lidiar con una posible elevación en el nivel del mar bajo los escenarios RCP 4.5 y 2.6 (4 y 7 mm, respectivamente).

ABSTRACT Background. Corals play a fundamental role in reef structure and function because of their ability to deposit calcium carbonate and contribute to the formation of complex three-dimensional structures. However, the functioning potential of a reef community, in terms of its building capacity, is affected by the relative abundance of coral species on the reef. Objectives. Evaluate the physical functionality of coral reefs at six sites in the Parque Nacional Zona Marina del Archipiélago Espíritu Santo (PNZMAES). Methods. The Reef Functional Index (RFI) was implemented as a metric of physical functionality; this tool considers the calcification rate, structural complexity, and abundance of coral species at each site. Results. Las Navajas and San Gabriel sites had the highest coral cover, with 74.72 % and 60.14 %, respectively, while La Ballena was the site with the lowest coral cover (6.77 %). In terms of IFA, the sites with the highest index were Las Navajas (0.68) and San Gabriel (0.65), dominated by Pocillopora meandrina and Pocillopora verrucosa corals, respectively. The site with the lowest IFA was La Ballena (0.35), with Pocillopora verrucosa being the predominant coral. Coral species of the genus Pocillopora were predominant in all sites and contributed the most to the Reef Function Index. Conclusions. The Reef Function Index helped to complement the information on the coral assemblage in the PNZMAES and to understand the performance of coral species in the reef functioning of the Mexican Pacific.

RESUMEN Antecedentes. Los corales desempeñan un papel fundamental en la estructura y función del arrecife debido a su capacidad para depositar carbonato de calcio y contribuir con la formación de estructuras tridimensionales complejas. Sin embargo, el potencial de funcionamiento de una comunidad arrecifal, en términos de su capacidad de construcción, es afectado por la abundancia relativa de las especies de coral que se encuentran en el arrecife. Objetivos. Evaluar la funcionalidad física de los arrecifes de coral en seis sitios del Parque Nacional Zona Marina del Archipiélago Espíritu Santo (PNZMAES). Métodos. Se implementó el Índice Funcional Arrecifal (IFA) como métrica de funcionalidad física; esta herramienta considera la tasa de calcificación, la complejidad estructural y la abundancia de las especies de coral en cada sitio. Resultados. Los sitios Las Navajas y San Gabriel presentaron la cobertura de coral mayor con 74.72 % y 60.14 %, respectivamente, mientras que La Ballena fue el sitio con menor cobertura coralina (6.77 %). En cuanto al IFA, los sitios que presentaron el mayor valor fueron Las Navajas (0.68) y San Gabriel (0.65), dominados por los corales Pocillopora meandrina y Pocillopora verrucosa, respectivamente. El sitio con menor IFA fue La Ballena (0.35), donde Pocillopora verrucosa predominó. Las especies de coral del género Pocillopora son los que predominaron en todos los sitios y los que tuvieron una mayor contribución al IFA. Conclusiones. El IFA ayudó a complementar la información del ensamblaje de corales en el PNZMAES y a entender el desempeño que tienen las especies de coral en el funcionamiento arrecifal del Pacífico mexicano.

Abstract Ca2+ and Mg2+ ions are present in the water of the sulfide flotation process, negatively affecting its floatability and grade of the final concentrates obtained. It has recently been reported that its removal by adding sodium carbonate (Na2CO3) has a beneficial effect on flotation, although the reasons for this behavior are not yet known in detail. This paper presents the results of a study designed to investigate the reaction mechanism between the metal-carbonate ions. The results show that the addition of Na2CO3 to a saturated gypsum solution (0.016 mol/L) containing 50 ppm Mg(II) promotes the precipitation of the Ca2+ ion, such as calcite and vaterite. The kinetic model proposed to describe the reaction’s kinetics suggests that it is about a second order kinetic.

Resumen Los iones Ca2+ y Mg2+ se encuentran presentes en las aguas del proceso de flotación de sulfuros, lo que afecta negativamente su flotabilidad y el grado de los concentrados finales obtenidos. Recientemente se ha reportado que su remoción mediante la adición de carbonato de sodio (Na2CO3) tiene un efecto benéfico en la flotabilidad, aunque las razones de este comportamiento aún no se conocen con detalle. Este documento presenta los resultados de un estudio diseñado para investigar el mecanismo de reacción entre iones metal-carbonato. Los resultados demuestran que la adición de Na2CO3 a una solución saturada de yeso (0.016 mol/L) conteniendo 50 ppm de Mg(II), promueve la precipitación del ión Ca2+, como calcita y vaterita. El modelo cinético propuesto para describir la cinética de reacción sugiere que se trata de una cinética de segundo orden.

Abstract The aim of this paper is s to expand the knowledge about the variability with which taphonomic agents impact on the archaeological record from the southern coast of the province of Santa Cruz, specifically, on the one that is part of shell middens found in the archaeological locality of Punta Entrada and Monte León National Park. For this, the lithic materials recovered in different exposure situations (stratigraphy and surface materials) which are dated in the Middle and Late Holocene are analyzed. Specifically, indicators of subaerial exposure and burial are used, such as the impact of wind erosion and the presence of calcium carbonate precipitates. Results are compared with the ones available for non-shell midden sites. It is concluded thatthere would be no differences in the way in which both taphonomic effects are expressed according to the kind of site that contains the artifacts.

Resumen El objetivo de este trabajo es ampliar el conocimiento acerca de la variabilidad con que los agentes tafonómicos impactan sobre el registro arqueológico proveniente de la costa meridional de la provincia de Santa Cruz, específicamente, de sitios concheros que se encuentran en la localidad arqueológica Punta Entrada y el Parque Nacional Monte León. Para ello se analizan los artefactos líticos recuperados en distinta situación de exposición (estratigrafía y materiales en superficie) recuperados en sitios concheros y datados en el Holoceno medio y tardío. Concretamente se utilizan indicadores de exposición subaérea y enterramiento como son el impacto de la erosión eólica y la presencia de precipitados de carbonato de calcio. Los resultados se comparan con los disponibles para sitios no concheros. Se concluye queno habría diferencias en la forma en la que se expresan ambos efectos tafonómicos según el tipo de sitiosen el que se hallan los artefactos.

Forward osmosis technology was evaluated for treating evaporator brine stream from a petrochemical industry at bench scale using ammonium bicarbonate as a draw solution. Calcium carbonate scaling that forms from the interaction between the calcium ions in the feed solution and carbonate ions from the draw solution (reverse salt diffusion) leads to the reduction in water flux and water recoveries achievable (feed TDS concentration of -60 000 mg-L-1, calcium -545 mg-L-1 and draw solution (ammonium bicarbonate) concentration of-240 000 mg-L-1). Fouling can be prevented by softening the feedwater before it is treated in forward osmosis. Without calcium and magnesium, permeate fluxes and water recoveries of up to 6L m-2·h-1 and 60%, respectively, could be achieved. It was also observed in this study that the concentration of the calcium ions in the feed does have an impact on the formation of the calcium carbonate scale, implying that some hardness can be tolerated in the feed to the forward osmosis process. It can, therefore, be concluded that without some hardness removal, ammonium bicarbonate draw solution is not suitable for treating concentrated brine streams (e.g., evaporator brine) that contain a high concentration of calcium ions. FO technology using ammonium bicarbonate as a draw solution can be considered an alternative technology to treat concentrated brine streams from inland industries, provided some pre-treatment to remove scaling precursors such as calcium is incorporated in the flow scheme.

Resumo As algas coralinas crustosas (Corallinophycideae) são algas vermelhas que produzem carbonato de cálcio e são bem reconhecidas como espécies de base na zona epipelágica do ecossistema marinho. Essas algas induziram o assentamento juvenil de coral por meio de estímulos químicos liberados por comunidades bacterianas na superfície de suas colônias. Seu carbonato de cálcio extracelular também pode estabilizar a estrutura do recife que influencia muitos invertebrados anexados e crescimento no fundo do mar. As algas coralinas crustosas (CCA) têm obtido atenção devido à sua distribuição e comprometimento da saúde com o aumento da temperatura da água do mar, acidificação dos oceanos e poluentes. Como uma espécie enigmática no ecossistema, a presença de recrutamento CCA às vezes não recebe atenção, especialmente em sua capacidade de ocupar o espaço vazio. Este estudo teve como objetivo documentar a cobertura e o número de recrutamento de CCA em dois materiais de recrutamento diferentes. A maior porcentagem de CCA da cobertura foi mostrada na superfície interna do que nas outras superfícies em todas as estações. A intensidade da luz e a baixa sedimentação foram sugeridas como um fator-chave para o sucesso da alta cobertura. De modo geral, recrutas de CCA mais graduados mostraram-se em Tiga Warna. A baixa sedimentação e a proteção contra a exposição aérea se tornaram a principal razão para isso. Não houve diferença significativa no número de recrutas CCA entre mármore e arenito neste estudo. O recrutamento bem-sucedido de CCA neste estudo pode dar uma imagem ampla de que o recrutamento natural de corais e outros recifes da biodiversidade no sul de Malang será bem-sucedido por causa da abundância de algas coralinas que sustentam seu estágio de história de vida.

Abstract Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn’t have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile’s material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.

ABSTRACT. Biochar is a carbon-rich material produced during organic waste pyrolysis. In this context, two experiments were performed to evaluate the effect of biochar produced from rice husks and cattle manure on soil fertility and common bean production, as well as to identify the optimal dose of cattle manure biochar to be applied. The first experiment (Experiment I) was conducted according to a completely randomized design (factorial scheme 2 × 2 × 2 + 1) with six replicates: two types of biochar (cattle manure biochar and rice husk biochar), with and without acidity correction [addition of calcium carbonate and magnesium carbonate (PA) in a proportion of 4:1 (Ca:Mg) to raise the soil base saturation to 60%], with or without the addition of 120 mg dm-3 of phosphorus (P) as ammonium phosphate, and a control treatment (without biochar, acidity correction, and P). Based on the results of Experiment I, a second experiment was conducted according to a completely randomized design, with five treatments (doses of biochar from cattle manure) and four replications. Rice husk biochar, as a conditioner of soil chemical properties, had less prominent effects than cattle manure biochar. Cattle manure biochar functioned as a corrective for soil acidity and a source of nutrients (mainly phosphorus). The dose corresponding to 5.46% of the soil volume led to the maximum grain production by common bean plants.

This work aims to evaluate, from a static and dynamic perspective, the performance of a polycarboxylic acid-based scale inhibitor in the presence of iron ions (FeIII). The static (jar test) and dynamic (tube blocking test) tests were performed according to NACE TM0197-2010 and NACE TM31105-2005 standards, respectively. The lowest inhibition concentration (LIC) was determined under flow conditions of oil wells. In addition, the influence of the concentration of FeIII ions on the precipitation process was also evaluated. The scale deposits were analyzed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results demonstrated that the scale inhibitor is chemically compatible and efficient with the selected brines, possessing a LIC of 30 mg L 1 in the absence of FeIII ions. In the presence of FeIII ions, the inhibitor proved to be inefficient and incompatible, and it was not possible to determine the LIC. The combined XRD, FTIR, and SEM analyses allowed us to identify the inhibitor’s mechanism of action as being one of complexation, poly(carboxylic acid)-Ca2+. Furthermore, analyses in the presence of FeIII ions demonstrated a significant change in the morphology of the incrustation of CaCO3 crystals. Additionally, it has been proven that FeIII ions significantly affect the performance of the inhibitor. Finally, the results indicated that in the absence of high concentrations of FeIII ions, the poly(carboxylic acid) scale inhibitors can be an option to mitigate operating costs resulting from the deposition of inorganic scale in oil wells.

ABSTRACT Golden mussel is an invasive species in South America that causes environmental and economic damage due to the formation of large colonies without natural predators. This study aimed to test the agricultural use of golden mussel shell as a limestone substitute, as the shell is rich in calcium carbonate. The experiment was carried out in pots, with eight treatments (sandy soil; clay soil; sandy soil + 1.0 Mg ha−1 of limestone; clay soil + 1.0 Mg ha−1 of limestone; sandy soil + 1.0 Mg ha−1 of fresh shell; clay soil + 1.0 Mg ha−1 of fresh shell; sandy soil + 1.0 Mg ha−1 of calcined shell; clay soil + 1.0 Mg ha−1 of calcined shell), in addition to the application of the following fresh and calcined shell doses: 0, 1.0, 1.5 and 2.0 Mg ha−1. Rice was cultivated in all treatments, and the soil fertility and rice shoot and root dry masses were evaluated. The shell provided good chemical conditions to the soils and raised their pH and phosphorus and calcium contents. The agricultural use of golden mussel shell showed to be efficient for soil correction and can be considered an alternative to limestone.

RESUMO O mexilhão-dourado é uma espécie invasora na América do Sul que causa prejuízos ambientais e econômicos, devido à formação de grandes colônias sem predadores naturais. Objetivou-se testar o uso agrícola de carapaça de mexilhão-dourado como substituto ao calcário, já que é rica em carbonato de cálcio. O experimento foi conduzido em vasos, com oito tratamentos (solo arenoso; solo argiloso; solo arenoso + 1,0 Mg ha−1 de calcário; solo argiloso + 1,0 Mg ha−1 de calcário; solo arenoso + 1,0 Mg ha−1 de carapaça in natura; solo argiloso + 1,0 Mg ha−1 de carapaça in natura; solo arenoso + 1,0 Mg ha−1 de carapaça calcinada; solo argiloso + 1,0 Mg ha−1 de carapaça calcinada), além da aplicação das seguintes doses de carapaça in natura e calcinada: 0; 1,0; 1,5; e 2,0 Mg ha−1. Cultivou-se arroz em todos os tratamentos e foram avaliadas a fertilidade do solo e a massa seca da parte aérea e das raízes do arroz. A carapaça proporcionou boas condições químicas aos solos, elevou o seu pH e os teores de fósforo e cálcio. A utilização agrícola da carapaça de mexilhão-dourado foi eficiente para a correção do solo e pode ser considerada uma alternativa ao calcário.