ALBERT

Description: The coagulation of hydrosols was investigated theoretically and experimentally. A reduced form of the particle size distribution function, designated “self-preserving,” was found to satisfy Smoluchowski's equations of coagulation by Brownian motion and shear flow. Brownian motion coagulation experiments with two heterogeneous hydrosols showed that the distributions were self-preserving. The rate of coagulation for heterogeneous systems was found to be second order in total particle concentration, consistent with the self-preserving form of the distribution function. Coagulation experiments were carried out in a simple laminar shear field using a homogeneous Dow polystyrene latex dispersion. Smoluchowski's shear flow theory was confirmed for shear rates ranging from 1 to 80 sec.−1 The shear coagulation of a heterogeneous emulsion was studied at several shear rates, and the size distributions were self-preserving.

Description: This chapter aims at introducing the reader to general concepts about the main forcings of the Mediterranean Sea, in terms of exchanges through the Strait of Gibraltar, and air-sea exchanges of heat, freshwater, and momentum. These forcings are also responsible for the peculiar characteristics of Mediterranean water masses. Therefore, the chapter continues with giving a general explanation on water mass analysis, and then it describes the properties and vertical and horizontal distributions of the main Mediterranean water masses. To conclude, the reader is introduced to the use of other (biogeochemical, and chemical) tracers of water masses, with a focus on the Mediterranean Sea.

Description: A key requirement for geological CO2 storage is site integrity management and monitoring during operation through to the post decommissioning period. This paper focuses on monitoring deformation of the ground surface and seabed as a proxy for overall deformation in the reservoir and surrounding layers. The objective is to inform, based on deformation data, on how the reservoir is responding to CO2 injection and to ensure any issues with regard to storage integrity are rapidly detected. The magnitude and pattern of deformation at the surface reveals geomechanical/hydromechanical processes that occur in reservoir due to CO2 injection. We acquired deformation data from the In Salah CO2 injection site and from four additional study cases during the course of this study; one in the onshore UK, the other a combined campaign onshore Norway and offshore Germany, and the third in onshore Japan. Significant developments in measurement techniques, processing tools and interpretation algorithms were developed through this project. Models were then developed to simulate the observed data and to couple surface deformation to displacement in the subsurface. The results show millimeter-scale deformations in the subsurface have a signature at the surface that can be captured by the tools and workflows developed in this project. These deformations, particularly the patterns, are important factors to consider when monitoring a CO2 storage site.

Description: Quantification of phthalates or phthalic acid esters (PAEs) might be problematic due to matrix overlap, auto-self absorbance and background scattering noise by the plastic lab materials although plastics have been reported in the release of PAEs. These materials (ambient air, reagents bottles, sampling devices, and various analytical instruments), are ubiquitous in the laboratory environment, thereby making it more difficult to reliably analyze of trace concentration of PAEs. Thus, in the current study, a straight forward and reliable protocol has been established for the analysis of PAEs including control of blank contamination, and the experimental conditions such as extraction time and temperature were optimized. The mass of PAEs in blank tests of selected materials ranged from 3±0.7 to 35±6 ng for liquid-liquid extraction (LLE) and from 5±1.8 to 63±15 ng for solid-phase extraction (SPE). For both extraction methods, higher blank values were measured for dibutyl phthalate (DBP) (35±6 ng, 12±3 ng), and DEHP (63±12 ng, 23±5 ng) in LLE and SPE, respectively. Average recoveries of PAEs in LLE were 90-97% and obtained with successive aliquots of 2 mL, 1 mL, and 1 mL dichloromethane (DCM). For SPE, recoveries up to 86-90% were achieved with successive aliquots of 5, 3, and 2 mL DCM at a sample flow rate of 5 mL min -1 . Under the optimized conditions, the method quantification limits (MQL) for PAEs was 10-20 ng L -1 for LLE and 10-35 ng L -1 for SPE. Moreover, the dissolved concentrations of PAEs from LDPE measured by the LLE method ranged 〈 1.5 to 5.83 ng cm -2, and those measured by SPE ranged from 1.0to256ngL -1 , in seawater samples of Sharm Obhur. The method has lower MQL values for LLE and SPE than average reported values of 10-100 ng L -1 and 30-100 ng L -1 , respectively.

Description: Phytoplankton form the base of the pelagic food web in inland waters. Unlike rooted plants with access to nutrients in the sediment, phytoplankton depend on the open water as their sole direct source of minerals. Phytoplankton comprise cyanobacteria and phylogenetically diverse eukaryotic algae that convert light energy and mineral nutrients into organic matter. Many species also exploit the elements and energy within dissolved organic compounds and particles produced in the catchment or within the water. Here, we describe the nutrient requirements of phytoplankton, their different modes of nutrition, the mechanisms they employ to acquire nutrients and the ecological consequences of their varying ability to exploit an often scarce and spatially and temporally variable resource. When nutrients are abundant, often as a result of human disruption of nutrient cycles, phytoplankton productivity, and often biomass, increases to the point that it causes a range of ecological consequences that reduce the value of the water resource for mankind.

Description: One of the best-known greenhouse gases, CO2, has been increasing in the last decade of about 1.7%. To overcome the well-known global problems related to this gas, researchers of all over the world are working very hard in order to develop any strategies to seriously solve this issue. In this chapter, the authors focus their attention on one of the possible solutions to the problem: bacteria that are CO2 capture cells which have carried out this task since ancient times. In our work we make an excursus on all the biochemical processes of CO2 capture carried out by bacteria, ending with a detailed comparison of the most studied enzymes. One of the alternatives will be to genetically modify the organisms known to date to speed up their conversion process.

Description: Wildfires are natural or anthropogenic phenomena increasing at alarming rates globally due to land-use alterations, droughts, climatic warming, hunting and biological invasions. Whereas wildfire effects on terrestrial ecosystems are marked and relatively well-studied, ash depositions into aquatic ecosystems have often remained overlooked but have the potential to significantly impact bottom-up processes. This study assessed ash-water-phytoplankton biomass dynamics using six plant species [i.e., three natives (apple leaf Philenoptera violacea, Transvaal milk plum Englerophytum magalismontanum, quinine tree Rauvolfia caffra) and three aliens (lantana Lantana camara, gum Eucalyptus camaldulensis, guava Psidium guajava)] based on a six-week mesocosm experiment with different ash concentrations (1 and 2 g L-1). We assessed concentrations of chemical elements, i.e., N, P, K, Ca, Mg, Na, Mn, Fe, Cu, Zn and B from ash collected, and we have observed significant differences among the species. High concentrations of P, K, Mn, Fe, Cu, Zn and B were recorded from Transvaal milk plum ash and low concentrations of P, K, Ca, Mg, Cu and Zn were recorded from apple leaf. An increase in phytoplankton biomass (using chlorophyll-a concentration as a proxy) for all treatments i.e., 1 and 2 g L-1 for all plant species ash was observed a week after, followed by decreases in the following weeks, with the exception of 2 g L-1 for lantana, gum and control. Silicate concentrations (i.e., used as a proxy for diatom abundance) showed increasing patterns among all ash treatments, with exception of controls. However, no clear patterns were observed between native and alien plant ash on both chl-a and silicate concentrations. We found that ash has notable effects on water chemistry, particularly nitrate, which increased throughout the weeks, whereas, pH and conductivity were high at low ash concentrations. The impacts of ash on water chemistry, chl-a and silicate concentrations vary with individual species and the amount of ash deposited into the system.

Description: Adaptive sampling and situational awareness for autonomous underwater vehicles (AUVs) is a major improvement in ocean research. By only sampling the feature of interest in a feature-relevant domain instead of a covering a whole area expensive ship time can be saved and at the same time a more comprehensive data set can be obtained. A classical marine example where adaptive sampling is useful is sampling of boundary layers such as the thermocline because the boundary layer thickness is very small compared to the depth of the water column. These boundary layers play an important role in many ocean related disciplines such as marine biology, physical oceanography and underwater acoustics. In this paper an unscented Kalman filter (UKF) based extremum seeking control (ESC) approach is presented to detect and track such boundary layers. Simulation results for different use cases are presented to show its effectiveness.

Description: The Q10 temperature coefficient, which is widely used in scientific literature, is a measure of the temperature sensitivity of chemical reaction rates or biological processes. However, the conclusions drawn from applying this coefficient to experimental data obtained from biological processes are not universal. In many biological processes, Q10 values are often discordant with the results predicted by the Arrhenius law. The hypothesis tested in the present study is that this problem arises mainly from the fact that the Q10 coefficient is defined by the ratio between rates described by exponential laws instead of power laws. Considering this hypothesis and the need to review the mathematical laws and models currently used to describe rates and Q10 coefficients, we propose a model beyond the usual Arrhenius theory or exponential decay law herein. The proposed mathematical model is based on the theory of deformed exponential functions, with the ordinary Q10 model representing the conventional exponential function. Therefore, all results following the standard model remain valid. Moreover, we include a Q10 free open-source code, written in Python, and compatible with Windows, Linux and macOS platforms. The validation of the proposed model and confirmation of the given hypothesis were performed based on the following temperature-dependent biological processes: soil organic carbon (SOC) decomposition (which is essential to forecast the impact of climate change on terrestrial ecosystems); the metabolism of Arctic zooplankton; physiological processes of the respiratory and cardiovascular systems; rate of oxygen consumption in mitochondria of the eurythermal killifish Fundulus heteroclitus, and leaf respiration.

Description: Highlights • Continuous CH4 bioelectrosynthesis from CO2 demonstrated with 80% or higher Coulombic Efficiency • At pH values below 8 CH4 cathodic off-gas contains up to 85% CH4 • At pH above 8.5, production of acetate and then ethanol (up to 8 g L−1) was obtained • Coulombic efficiency remained above 80% • 16S sequencing showed proliferation of Clostridium, Methanosaeta, Methanobrevibacter and Methanobacterium spp at the cathode This study demonstrates the continuous conversion of CO2 to methane, acetate, and ethanol in a Microbial Electrosynthesis Cell (MESC) with a carbon felt biocathode. The MESC was inoculated with a mixed anaerobic microbial consortium and operated at a mesophilic temperature of 30 °C. In situ deposition of Ni and Fe was achieved by introducing 0.2 g L−1 of NiSO4 or FeSO4, respectively, into the cathode compartment influent stream. In response, a considerable improvement in MESC performance was observed with a current density of 6.4 mA cm−2 (per separator area) and a CH4 production of 0.83 L (LR d)−1 (R = cathode volume). Once Ni and Fe were removed from the influent solution, the performance remained unchanged. Electron dispersive spectroscopy confirmed Ni and Fe electrodeposition. A shift from CH4 to acetate and ethanol production with concentrations reaching 5 and 8 g L−1, respectively, was observed upon increasing the cathode compartment pH to 8.5–9.0. 16S rRNA gene sequencing showed significant changes in the bacterial population at the cathode with Clostridia representing almost two-thirds of the population. Methanosaeta, Methanobrevibacter, and Methanobacterium species dominated the archaeal community.